CBFilter Component

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The CBFilter component allows applications to intercept and control filesystem requests.

Syntax

callback.CBFSFilter.Cbfilter

Remarks

The CBFilter component gives applications the ability to intercept filesystem requests, allowing them to be altered, handled, or blocked. Applications use standard filter rules to specify which requests they are interested in intercepting; and special filter rules to enforce access restrictions and redirect requests to different files.

To learn more about the component's capabilities, please refer to the product's General Information topics.

Getting Started

  1. If the component's system driver has not been installed yet, call the Install method to do so. This needs to be done only once.
    • In production, the driver can be installed (or updated) ahead of time with the application's installation script using the Installer DLL. Please refer to the Driver Installation topic for more information.
  2. Call the Initialize method to initialize the CBFilter component. This must be done each time the application starts.
  3. Add one or more filter rules using methods like AddFilterRule. (Rules can also be added or removed after the filter is started.)
  4. Call the StartFilter method to start filtering filesystem requests.
  5. When finished, call the StopFilter method to stop filtering filesystem requests.
  6. To uninstall the component's system driver, call the Uninstall method. This should not be done as part of the driver upgrade process.
    • In production, the driver can be uninstalled by the application's uninstallation script using the Installer DLL. Please refer to the Driver Installation topic for more information.

Property List


The following is the full list of the properties of the component with short descriptions. Click on the links for further details.

ActiveThis property notes whether the component is active and processing requests.
AltitudeThis property specifies the altitude the component's system driver should use .
DefaultRulesThis property includes the collection of default rules.
FileFlushingBehaviorThis property specifies the file flushing and closing behavior that the component's system driver should enforce.
FilterRulesThis property includes a collection of filter rules.
FireVolumeEventsThis property specifies the events that should be fired when a filesystem volume is mounted to or unmounted from the system.
PassthroughRulesThis property includes a collection of passthrough rules.
ProcessCachedIORequestsThis property specifies whether cached file read/write requests should be processed.
ProcessFailedRequestsThis property specifies whether failed requests should be processed.
ReparseRulesThis property includes a collection of reparse rules.
SerializeEventsWhether events should be fired on a single worker thread, or many.
TagThis property stores application-defined data specific to a particular instance of the component.

Method List


The following is the full list of the methods of the component with short descriptions. Click on the links for further details.

AddBytesToWriteBufferThis method reserves extra space in the file data buffers used in file read/write events.
AddDefaultRuleThis method adds a default rule.
AddFilterRuleThis method adds a standard filter rule or access rule.
AddFilterRuleExThis method adds a standard filter rule or access rule with additional match qualifiers.
AddPassthroughRuleThis method adds a passthrough rule.
AddPassthroughRuleExThis method adds a passthrough rule with additional match qualifiers.
AddReparseRuleThis method adds a reparse rule.
CloseDefaultRulesSnapshotThis method closes the previously created default rules snapshot.
CloseReparseRulesSnapshotThis method closes the previously created reparse rules snapshot.
ConfigSets or retrieves a configuration setting.
CreateDefaultRulesSnapshotThis method creates a snapshot of information about the default rules that have been added.
CreateFileDirectThis method creates or opens a file or directory by passing the request directly to the filesystem.
CreateFileDirectAsStreamThis method creates or opens a file by passing the request directly to the filesystem.
CreateReparseRulesSnapshotThis method creates a snapshot of information about the reparse rules that have been added.
CreateVirtualFileThis method is under construction.
DeleteAllFilterRulesThis method deletes all standard filter rules and access rules.
DeleteAllPassthroughRulesThis method deletes all passthrough rules.
DeleteAllReparseRulesThis method deletes all reparse rules.
DeleteDefaultRuleThis method deletes a particular default rule.
DeleteFilterRuleThis method deletes a particular standard filter rule or access rule.
DeletePassthroughRuleThis method deletes a particular passthrough rule.
DeleteReparseRuleThis method deletes a particular reparse rule.
FileMatchesMaskThis method checks whether a particular file or directory name matches the specified mask.
GetDriverStatusThis method retrieves the status of the component's system driver.
GetDriverVersionThis method retrieves the version of the component's system driver.
GetEventFilenameThis method retrieves the name of the file or directory, to which the event applies.
GetHandleCreatorProcessIdThis method retrieves the Id of the process (PID) that opened the file handle.
GetHandleCreatorProcessNameThis method retrieves the name of the process that opened the file handle.
GetHandleCreatorThreadIdThis method retrieves the Id of the thread that opened the file handle.
GetHandleCreatorTokenThis method retrieves the security token associated with the process that opened the file handle.
GetOperationTimeThis method returns the time at which the request was received by the filter driver.
GetOriginatorProcessIdRetrieves the Id of the process (PID) that initiated the operation.
GetOriginatorProcessNameRetrieves the name of the process that initiated the operation.
GetOriginatorThreadIdRetrieves the Id of the thread that initiated the operation.
GetOriginatorTokenRetrieves the security token associated with the process that initiated the operation.
GetRemoteAccessInformationThis method returns networking-related information about the operation.
GetReparseRuleByMaskThis method retrieves the reparse rule associated with the specified file mask.
GetVolumeGUIDThis method retrieves the volume GUID of the device targeted by a filesystem operation.
InitializeThis method initializes the component.
InstallThis method installs (or upgrades) the component's system driver.
IsFileFilteredThis method checks whether a particular file or directory is covered by any filter rules.
NtStatusToWin32ErrorThis method converts a native status code to a Win32 error code.
ResetTimeoutThis method resets the timeout duration for the current event handler.
SetFileInformationDirectThis method sets the file information of a file opened using CreateFileDirect.
SetFileSizeDirectThis method resizes a file by passing the request directly to the filesystem.
ShutdownSystemShuts down or reboots the operating system.
StartFilterThis method starts filtering filesystem operations.
StopFilterThis method stops filtering filesystem operations.
SuspendDefaultRulesThis method suspends all default rules until the application exits.
SuspendFileEventsThis method suspends all events for a particular file or directory until all of its handles have been closed.
ToggleProcessProtectionThis method enables or disables termination protection for the application.
UninstallThis method uninstalls the component's system driver.

Event List


The following is the full list of the events fired by the component with short descriptions. Click on the links for further details.

AfterCanFileBeDeletedThis event fires after the OS marks a file or directory for deletion or removes such a mark.
AfterCleanupFileThis event fires after a file or directory handle is closed.
AfterCloseEnumerationThis event fires after a directory enumeration operation finishes.
AfterCloseFileThis event fires after a file or directory is closed.
AfterCreateFileThis event fires after a file or directory is created.
AfterCreateHardLinkThis event fires after a hard link is created.
AfterDeleteFileThis event fires after a file or directory is deleted.
AfterDeleteReparsePointThis event fires after the OS deletes a reparse point from a file or directory.
AfterEnumerateDirectoryThis event fires after a directory entry is returned during directory enumeration.
AfterFilterAttachToVolumeThis event fires after the filter attaches to a newly mounted filesystem volume.
AfterFilterDetachFromVolumeThis event fires after the filter detaches from a filesystem volume.
AfterFsctlThis event fires after an IRP_MJ_FILE_SYSTEM_CONTROL request is processed.
AfterGetFileSecurityThis event fires after a file or directory's security attributes are retrieved.
AfterGetFileSizesThis event fires after a file's size information is retrieved.
AfterGetReparsePointThis event fires after a file or directory's reparse point information is retrieved.
AfterIoctlThis event fires after an IRP_MJ_DEVICE_CONTROL request is processed.
AfterLockThis event fires after a range of bytes in a file is locked.
AfterOpenFileThis event fires after a file or directory is opened.
AfterQueryEaThis event fires after information about extended attributes of a file is retrieved.
AfterQueryFileInfoThis event fires after information about a file or directory is retrieved.
AfterReadFileThis event fires after data are read from a file.
AfterRenameOrMoveFileThis event fires after a file or directory is renamed or moved.
AfterSetAllocationSizeThis event fires after a file's allocation size is changed.
AfterSetEaThis event fires after extended attributes of a file are changed.
AfterSetFileAttributesThis event fires after a file or directory's attributes or times are changed.
AfterSetFileInfoThis event fires after information about a file or directory is changed.
AfterSetFileSecurityThis event fires after a file or directory's security attributes are changed.
AfterSetFileSizeThis event fires after a file is resized.
AfterSetReparsePointThis event fires after the OS creates or updates a reparse point on a file or directory.
AfterUnlockAllThis event fires after all locked byte ranges in a file are unlocked.
AfterUnlockAllByKeyThis event fires after all locked byte ranges in a file, associated with a particular key, are unlocked.
AfterUnlockSingleThis event fires after a particular locked byte range in a file is unlocked.
AfterWriteFileThis event fires after data are written to a file.
BeforeCanFileBeDeletedThis event fires before the OS attempts to mark a file or directory for deletion or remove such a mark.
BeforeCleanupFileThis event fires before a file or directory handle is closed.
BeforeCloseFileThis event fires before a file or directory is closed.
BeforeCreateFileThis event fires before a file or directory is created.
BeforeCreateHardLinkThis event fires before a hard link is created.
BeforeDeleteFileThis event fires before a file or directory is deleted.
BeforeDeleteReparsePointThis event fires when the OS wants to delete a reparse point from a file or directory.
BeforeEnumerateDirectoryThis event fires when an enumeration request is sent by the OS.
BeforeFilterAttachToVolumeThis event fires before the filter attaches to a newly mounted filesystem volume.
BeforeFsctlThis event fires before an IRP_MJ_FILE_SYSTEM_CONTROL request is processed.
BeforeGetFileSecurityThis event fires before a file or directory's security attributes are retrieved.
BeforeGetReparsePointThis event fires when the OS wants to read a reparse point for a file or directory.
BeforeIoctlThis event fires before an IRP_MJ_DEVICE_CONTROL request is processed.
BeforeLockThis event fires before a range of bytes in a file is locked.
BeforeOpenFileThis event fires before a file or directory is opened.
BeforeQueryEaThis event fires before information about extended attributes of a file is retrieved.
BeforeQueryFileInfoThis event fires before information about a file or directory is retrieved.
BeforeReadFileThis event fires before data are read from a file.
BeforeRenameOrMoveFileThis event fires before a file or directory is renamed or moved.
BeforeSetAllocationSizeThis event fires before a file's allocation size is changed.
BeforeSetEaThis event fires before extended attributes of a file are changed.
BeforeSetFileAttributesThis event fires before a file or directory's attributes or times are changed.
BeforeSetFileInfoThis event fires before information about a file or directory is changed.
BeforeSetFileSecurityThis event fires before a file or directory's security attributes are changed.
BeforeSetFileSizeThis event fires before a file is resized.
BeforeSetReparsePointThis event fires when the OS wants to create or update a reparse point on a file or directory.
BeforeUnlockAllThis event fires before all locked byte ranges in a file are unlocked.
BeforeUnlockAllByKeyThis event fires before all locked byte ranges in a file, associated with a particular key, are unlocked.
BeforeUnlockSingleThis event fires before a particular locked byte range in a file is unlocked.
BeforeWriteFileThis event fires before data are written to a file.
CleanupContextThis event fires when the application-defined data stored in one or more contexts need to be cleaned up.
ErrorThis event fires if an unhandled error occurs during an event.
FilterStartThis event fires once the filter has attached and filtering has started.
FilterStopThis event fires once filtering has stopped and the filter has detached.
NotifyCanFileBeDeletedThis event fires when the OS marks a file or directory for deletion or removes such a mark.
NotifyCleanupFileThis event fires when a file or directory handle has been closed.
NotifyCloseFileThis event fires when a file or directory has been closed.
NotifyCreateFileThis event fires when a file or directory has been created.
NotifyCreateHardLinkThis event fires when a hard link has been created.
NotifyDeleteFileThis event fires when a file or directory has been deleted.
NotifyDeleteReparsePointThis event fires when a file or directory's reparse point has been deleted.
NotifyEnumerateDirectoryThis event fires when a directory entry has been returned during directory enumeration.
NotifyFilterAttachToVolumeThis event fires when the filter has been attached to a newly mounted filesystem volume.
NotifyFilterDetachFromVolumeThis event fires when the filter has been detached from a filesystem volume.
NotifyFsctlThis event fires when an IRP_MJ_FILE_SYSTEM_CONTROL operation has occurred.
NotifyGetFileSecurityThis event fires when a file or directory's security attributes have been retrieved.
NotifyGetFileSizesThis event fires when a file's size information has been retrieved.
NotifyGetReparsePointThis event fires when a file or directory's reparse point information has been retrieved.
NotifyIoctlThis event fires when an IRP_MJ_DEVICE_CONTROL operation has occurred.
NotifyLockThis event fires when a range of bytes in a file has been locked.
NotifyOpenFileThis event fires when a file or directory has been opened.
NotifyQueryEaThis event fires when information about the extended attributes of a file has been retrieved.
NotifyQueryFileInfoThis event fires when information about a file or directory has been retrieved.
NotifyReadFileThis event fires when data have been read from a file.
NotifyRenameOrMoveFileThis event fires when a file or directory has been renamed or moved.
NotifySetAllocationSizeThis event fires when a file's allocation size has been changed.
NotifySetEaThis event fires when information about the extended attributes of a file has been changed.
NotifySetFileAttributesThis event fires when a file or directory's attributes or times have been changed.
NotifySetFileInfoThis event fires when information about a file or directory has been changed.
NotifySetFileSecurityThis event fires when a file or directory's security attributes have been changed.
NotifySetFileSizeThis event fires when a file has been resized.
NotifySetReparsePointThis event fires when a file or directory's reparse point has been created or updated.
NotifyUnlockAllThis event fires when all locked byte ranges in a file have been unlocked.
NotifyUnlockAllByKeyThis event fires when all locked byte ranges in a file, associated with a particular key, have been unlocked.
NotifyUnlockSingleThis event fires when a particular locked byte range in a file has been unlocked.
NotifyWriteFileThis event fires when data have been written to a file.
ReparseFileNameThis event fires to allow file access to be dynamically redirected to another location.
ReparseWithTagThis event fires if an open operation returns STATUS_REPARSE so that the application can respond to the reparse point.
WorkerThreadCreationFires just after a new worker thread is created.
WorkerThreadTerminationFires just before a worker thread is terminated

Config Settings


The following is a list of config settings for the component with short descriptions. Click on the links for further details.

AllowFileAccessInBeforeOpenWhether file access, via the CreateFileDirect method, is allowed in during the BeforeCreateFile and BeforeOpenFile events.
AlwaysPrepareFilesWhether the driver should keep track of information for files that are already open when (i.e., were opened before) the component is initialized.
AlwaysRequestAttributesOnOpenWhether the driver should keep request existing attributes before file create/open operation.
CacheRemoteFilesLocallyWhether remote files involved in filtered operations should be cached locally rather than remotely.
DirectRequestsDownTheStackWhether requests for handles created with the CreateFileDirect method go down the filter stack and not direct to the filesystem.
FilterOwnRequestsWhether the component's system driver should filter requests made by the application itself.
ForceAdminRightsForDefaultRulesSpecifies whether default rules can be added or deleted only by administrators.
ForceAppPermissionCheckWhether the driver should require the controller process to have elevated or system privileges.
ForceSecurityChecksWhether the driver should prevent the controller process from filtering files that it would not normally have access to.
LoggingEnabledWhether extended logging is enabled.
MaxWorkerThreadCountThe maximum number of worker threads to use to fire events.
MinWorkerThreadCountThe minimum number of worker threads to use to fire events.
ModifiableReadWriteBuffersWhether the driver should duplicate read/write buffers sent to the user.
OmitEventFilenamesWhether the filename parameter should be empty in events.
PassSecurityInFileOpenEventsWhether security information, associated with the file create/open request, is passed to file creation and opening events.
PreprocessedRulesCacheSizeMaximum number of preprocessed rules to keep cached.
RecordOperationTimeEnables collection of operation time.
ResolveNtDeviceToDriveLetterWhether native device names are translated to drive letters.
SendRequestsViaDriverStackWhether internal requests to the filesystem are sent directly to the filesystem driver or through the stack of filesystem filter drivers.
SerializeAccessWhether nonintersecting operations against the same file should execute serially or in parallel.
TranslateDOSCharsInEnumMasksWhether the DOS wildcard characters should be translated during search.
WorkerInitialStackSizeThe initial stack size to create worker threads with.
BuildInfoInformation about the product's build.
LicenseInfoInformation about the current license.

Active Property (CBFilter Component)

This property notes whether the component is active and processing requests.

Syntax

public bool Active { get; }
Public ReadOnly Property Active As Boolean

Default Value

False

Remarks

This property reflects whether the component is active and currently processing requests. It will be true after the filter has been attached successfully via a call to StartFilter.

This property is read-only and not available at design time.

Altitude Property (CBFilter Component)

This property specifies the altitude the component's system driver should use .

Syntax

public string Altitude { get; set; }
Public Property Altitude As String

Default Value

""

Remarks

This property specifies the altitude that the component's system driver should use . A driver's altitude determines its absolute position in the stack of filter drivers; drivers with higher altitudes are attached toward the top of the stack, closer to the user mode, which allows them to process requests earlier.

Microsoft manages and assigns filesystem minifilter driver altitudes directly, so an application-specific altitude value must be obtained from Microsoft before an application is deployed in production. Please refer to the Driver Altitudes topic for more information. During development, an appropriate arbitrary value, such as 360000 (which is not registered with Microsoft), can be used.

If this property is queried before an altitude has been set (via this property or the Install method), it will return an empty string.

Note: This property cannot be changed when Active is true. Additionally, the Initialize method must be called before attempting to get or set this property's value, which is stored in the registry.

DefaultRules Property (CBFilter Component)

This property includes the collection of default rules.

Syntax

public FileDefaultRuleList DefaultRules { get; }
Public ReadOnly Property DefaultRules As FileDefaultRuleList

Remarks

This property holds a collection of FileDefaultRule objects, each of which represents a default rule. Please refer to the Default Rules topic for more information.

Use the following methods to manage default rules:

Note: Because default rules are managed by the component's system driver, this collection is not populated by default, nor is it updated by any of the aforementioned methods. Applications can call the CreateDefaultRulesSnapshot method to populate this collection; and must call the CloseDefaultRulesSnapshot method when finished working with it to release the associated memory.

Note: The methods and properties related to rule management are not intended to be used from multiple threads at once. Applications that wish to use said methods and properties from multiple threads (e.g., during the AfterFilterAttachToVolume and AfterFilterDetachFromVolume events) are responsible for employing proper thread synchronization techniques to ensure that manipulation and enumeration of the rule lists both occur in a thread-safe manner.

This property is read-only and not available at design time.

Please refer to the FileDefaultRule type for a complete list of fields.

FileFlushingBehavior Property (CBFilter Component)

This property specifies the file flushing and closing behavior that the component's system driver should enforce.

Syntax

public int FileFlushingBehavior { get; set; }
Public Property FileFlushingBehavior As Integer

Default Value

0

Remarks

This property specifies what file flushing and closing behaviors the component's system driver should enforce.

Applications that modify file data as it is being read or written may need to change this property's value to function correctly. For example, applications that provide on-the-fly encryption should choose the proper flags to ensure that other applications that have opened the files being encrypted cannot accidentally write nonencrypted data to the disk.

Applications that do not modify file data as it is being read or written can leave this property unchanged.

The value of this property should be constructed by ORing together zero or more of the following flags:

FS_FLUSH_FILES_ON_OPEN1Whether memory-mapped file data should be flushed to disk before files are opened.

This flag indicates that the component's system driver should flush any cached and memory-mapped file data, leftover from the last time a file was opened, before opening it again. Doing so ensures that file data are read directly from the disk rather than from the old memory mapping.

Applications that modify file data as it is being read may need to set this flag to function correctly. For example, applications that provide on-the-fly encryption should set this flag to ensure that file data are always read from the disk (and thus have a chance to get decrypted) when a file is opened.

Applications that do not modify file data as it is being read should leave this flag unset to maintain optimal performance when opening files.

FS_FLUSH_FILES_ON_CLOSE2Whether file buffers must be flushed when files are closed.

This flag indicates that the component's system driver should flush and clear the buffers of files that are opened for writing (and have had data written to them) when they are closed.

Applications that modify file data as it is being written may need to set this flag to function correctly. For example, applications that provide on-the-fly encryption should set this flag to ensure that all file data are flushed to the disk (and thus has a chance to get encrypted) when a file is closed.

Applications that do not modify file data as it is being written can unset this flag.

After a file is flushed, all in-memory buffers and memory mappings are cleared to avoid leakage of unprotected information.

FS_CLOSE_FILES_ON_STOPFILTER4Whether files opened for writing must be closed when the application stops filtering.

This flag indicates that the component's system driver should close files that are opened for writing (and have had data written to them) when the application calls StopFilter.

Applications that modify file data as it is being written (e.g., on-the-fly encryption) may need to set this flag to prevent further operations against the file data from being performed. Applications that do not modify file data as it is being written can leave this flag unset.

Note: If memory mappings of some file exist, these mappings will remain active; only the open handles to such files are closed.

When the file is closed, all in-memory buffers and memory mappings are cleared to avoid leakage of unprotected information. Applications can control whether file data are flushed before files are closed using the FS_FLUSH_FILES_ON_STOPFILTER flag; any data that are not flushed get discarded.

FS_FLUSH_FILES_ON_STOPFILTER8Whether file buffers must be flushed when the application stops filtering.

This flag indicates that the component's system driver should flush and clear the buffers of files that are opened for writing (and have had data written to them) when the application calls StopFilter.

Applications that modify file data as it is being written (e.g., on-the-fly encryption) may need to set this flag to ensure that no unprotected data are kept in memory, but rather has a chance to be encrypted and written out to disk. Applications that do not modify file data as it is being written can leave this flag unset.

If the application will not be able to perform on-the-fly data modification at the moment when StopFilter is called (e.g., because a cryptographic hardware module is unplugged), then this flag should be unset before calling StopFilter.

After a file is flushed, all in-memory buffers and memory mappings are cleared to avoid leakage of unprotected information.

FS_CLOSE_FILES_ON_CRASH16Whether files opened for writing must be closed if the application terminates unexpectedly.

This flag indicates that the component's system driver should close files that are opened for writing (and have had data written to them) if the driver detects that the application has terminated.

Applications that modify file data as it is being written (e.g., on-the-fly encryption) may need to set this flag to prevent further operations against the file data from being performed. Applications that do not modify file data as it is being written can leave this flag unset.

Note: If memory mappings of some file exist, these mappings will remain active; only the open handles to such files are closed.

When the file is closed, all in-memory buffers and memory mappings are cleared to avoid leakage of unprotected information.

FS_FLUSH_FILES_ON_CRASH32Whether file buffers must be flushed if the application terminates unexpectedly.

This flag indicates that the component's system driver should flush and clear the buffers of files that are opened for writing (and have had data written to them) if the driver detects that the application has terminated.

Applications that do not modify data as it is being written may set this flag if necessary. Applications that modify data as it is being written (e.g., on-the-fly encryption) should not set this flag, because such flushing could cause unprotected data to be written out to disk.

FS_SUPPORT_FILE_ENCRYPTION31Combination of flags suitable for on-the-fly file encryption applications.

This option includes the following flags: FS_FLUSH_FILES_ON_OPEN, FS_FLUSH_FILES_ON_CLOSE, FS_CLOSE_FILES_ON_STOPFILTER, FS_FLUSH_FILES_ON_STOPFILTER, and FS_CLOSE_FILES_ON_CRASH flags.

FilterRules Property (CBFilter Component)

This property includes a collection of filter rules.

Syntax

public FileFilterRuleList FilterRules { get; }
Public ReadOnly Property FilterRules As FileFilterRuleList

Remarks

This property holds a collection of FileFilterRule objects, each of which represents a standard filter rule, access rule, or both. Please refer to the File and Registry Filter Rules and Access Rules topics for more information.

Use the following methods to manage the rules in this collection:

Note: The methods and properties related to rule management are not intended to be used from multiple threads at once. Applications that wish to use said methods and properties from multiple threads (e.g., during the AfterFilterAttachToVolume and AfterFilterDetachFromVolume events) are responsible for employing proper thread synchronization techniques to ensure that manipulation and enumeration of the rule lists both occur in a thread-safe manner.

This property is read-only and not available at design time.

Please refer to the FileFilterRule type for a complete list of fields.

FireVolumeEvents Property (CBFilter Component)

This property specifies the events that should be fired when a filesystem volume is mounted to or unmounted from the system.

Syntax

public int FireVolumeEvents { get; set; }
Public Property FireVolumeEvents As Integer

Default Value

0

Remarks

This property specifies the events that the component should fire when a filesystem volume is mounted to or unmounted from the system. Possible values are as follows:

FS_MOUNT_IGNORE0Don't fire any events when volumes are mounted or unmounted.

FS_MOUNT_NOTIFY64Fire Notification Events when volumes are mounted or unmounted.

The NotifyFilterAttachToVolume and NotifyFilterDetachFromVolume events will fire, asynchronously, as necessary.

FS_MOUNT_CONTROL128Fire Control Events when volumes are mounted or unmounted.

The BeforeFilterAttachToVolume, AfterFilterAttachToVolume, and AfterFilterDetachFromVolume events will fire, synchronously, as necessary.

FS_MOUNT_BOTH192Fire all events when volumes are mounted or unmounted.

Note: The aforementioned events are fired only for volumes mounted/unmounted after the StartFilter method is called. Typically, applications use these events to dynamically add or remove volume-specific filter rules that target removable volumes (e.g., USB drives) as well as to create virtual files on such volumes. Please refer to the File Masks topic for more information.

PassthroughRules Property (CBFilter Component)

This property includes a collection of passthrough rules.

Syntax

public FilePassthroughRuleList PassthroughRules { get; }
Public ReadOnly Property PassthroughRules As FilePassthroughRuleList

Remarks

This property holds a collection of FilePassthroughRule objects, each of which represents a passthrough rule. Please refer to the Passthrough Rules topic for more information.

Use the following methods to manage the rules in this collection:

Note: The methods and properties related to rule management are not intended to be used from multiple threads at once. Applications that wish to use said methods and properties from multiple threads (e.g., during the AfterFilterAttachToVolume and AfterFilterDetachFromVolume events) are responsible for employing proper thread synchronization techniques to ensure that manipulation and enumeration of the rule lists both occur in a thread-safe manner.

This property is read-only and not available at design time.

Please refer to the FilePassthroughRule type for a complete list of fields.

ProcessCachedIORequests Property (CBFilter Component)

This property specifies whether cached file read/write requests should be processed.

Syntax

public bool ProcessCachedIORequests { get; set; }
Public Property ProcessCachedIORequests As Boolean

Default Value

False

Remarks

This property specifies whether the component's system driver should process cached file read/write requests (i.e., fire *ReadFile and *WriteFile events for them). Please refer to the Cached and Non-Cached Requests topic for more information.

Note: This property cannot be changed when Active is true.

ProcessFailedRequests Property (CBFilter Component)

This property specifies whether failed requests should be processed.

Syntax

public bool ProcessFailedRequests { get; set; }
Public Property ProcessFailedRequests As Boolean

Default Value

False

Remarks

This property specifies whether the component's system driver should process failed requests (i.e., fire After* or Notify* events for them).

When this property is enabled, applications can inspect the Status parameter of the aforementioned events to determine whether an operation has failed. If an operation fails, then the corresponding event's Status parameter will contain a nonzero native status code. Applications generally can use the NtStatusToWin32Error method to convert these status codes into Win32 error codes (but keep in mind that not all native status codes have direct Win32 error code mapping).

ReparseRules Property (CBFilter Component)

This property includes a collection of reparse rules.

Syntax

public FileReparseRuleList ReparseRules { get; }
Public ReadOnly Property ReparseRules As FileReparseRuleList

Remarks

This property holds a collection of FileReparseRule objects, each of which represents a reparse rule. Please refer to the Reparse Rules topic for more information.

Use the following methods to manage reparse rules:

Note: Because reparse rules are managed by the component's system driver, this collection is not populated by default, nor is it updated by any of the aforementioned methods. Applications can call the CreateReparseRulesSnapshot method to populate this collection; and must call the CloseReparseRulesSnapshot method when finished working with it to release the associated memory.

Note: The methods and properties related to rule management are not intended to be used from multiple threads at once. Applications that wish to use said methods and properties from multiple threads (e.g., during the AfterFilterAttachToVolume and AfterFilterDetachFromVolume events) are responsible for employing proper thread synchronization techniques to ensure that manipulation and enumeration of the rule lists both occur in a thread-safe manner.

This property is read-only and not available at design time.

Please refer to the FileReparseRule type for a complete list of fields.

SerializeEvents Property (CBFilter Component)

Whether events should be fired on a single worker thread, or many.

Syntax

public CbfilterSerializeEvents SerializeEvents { get; set; }

enum CbfilterSerializeEvents { seOnMultipleThreads, seOnOneWorkerThread }
Public Property SerializeEvents As CbfilterSerializeEvents

Enum CbfilterSerializeEvents seOnMultipleThreads seOnOneWorkerThread End Enum

Default Value

0

Remarks

This property specifies whether the component should fire all events serially on a single worker thread, or concurrently on multiple worker threads. The possible values are:

0 (seOnMultipleThreads) The component fires events in the context of multiple worker threads. The MinWorkerThreadCount and MaxWorkerThreadCount configuration settings control how many worker threads are used for this.
1 (seOnOneWorkerThread) The component fires events in the context of one background worker thread.

Please refer to the Threading and Concurrency topic for more information.

Note: This property cannot be changed when Active is true, and it cannot be changed within events.

Tag Property (CBFilter Component)

This property stores application-defined data specific to a particular instance of the component.

Syntax

public long Tag { get; set; }
Public Property Tag As Long

Default Value

0

Remarks

This property can be used to store data specific to a particular instance of the component.

AddBytesToWriteBuffer Method (CBFilter Component)

This method reserves extra space in the file data buffers used in file read/write events.

Syntax

public bool AddBytesToWriteBuffer(int extraBytes);
Public Function AddBytesToWriteBuffer(ByVal ExtraBytes As Integer) As Boolean

Remarks

Applications that plan to add additional data when files are being read or written should call this method to specify how much extra space to reserve in the file data buffers used in the BeforeReadFile, AfterReadFile, BeforeWriteFile, and AfterWriteFile events. If successful, this method returns true; otherwise, it returns false.

The ExtraBytes parameter specifies how many bytes to reserve.

Note: The value passed for this parameter must be a multiple of 512.

Note: This method cannot be called when Active is true.

AddDefaultRule Method (CBFilter Component)

This method adds a default rule.

Syntax

public bool AddDefaultRule(string mask, int accessFlags, string productGUID);
Public Function AddDefaultRule(ByVal Mask As String, ByVal AccessFlags As Integer, ByVal ProductGUID As String) As Boolean

Remarks

This method adds a default rule for the files and directories that match the specified Mask. Each rule in a ruleset is uniquely identified by its mask; if a rule with the specified mask already exists, the new rule's parameters are merged into it.

If the rule is added successfully, this method returns true; otherwise, it returns false.

Default rules, like access rules, instruct the component's system driver to apply certain access restrictions to matching files and directories. However, unlike access rules, default rules are managed by the driver directly; they are activated as soon as the driver loads at boot time, and then continue to be enforced at all times, regardless of whether the application that added them is open.

The Mask parameter must be a valid file mask according to the File Masks topic. Only the files and directories that match the specified mask will be covered by the rule.

The AccessFlags parameter specifies which access restrictions the component's system driver should apply to matching files and directories. The value passed for this parameter should be constructed by ORing together zero or more of the following flags:

ACCESS_NONE0x00No access restrictions.

ACCESS_READ_ONLY0x01Read-only access; writing and deleting are prohibited.

ACCESS_WRITE_ONLY0x02Write-only access; reading and deleting are prohibited.

ACCESS_DELETE_PROTECT0x04Deleting and renaming are prohibited.

ACCESS_EXECUTE_PROTECT0x08Execution is prohibited.

ACCESS_NO_CHANGE_DAC0x10Change of security attributes is prohibited.

ACCESS_NO_CHANGE_OWNER0x20Change of owner is prohibited.

ACCESS_RENAME_PROTECT0x40Renaming is prohibited.

ACCESS_DELETE_ONLY_PROTECT0x80Deleting is prohibited (renaming is not affected).

ACCESS_REMOTE_ACCESS_PROTECT0x100Access from other systems is prohibited.

ACCESS_DENY_ALL0x200All access is denied.

ACCESS_ALL_FLAGS-1Used to denote all currently set access restriction flags.

The ProductGUID parameter identifies the application that the rule should be associated with in the registry. In most cases, the value passed for this parameter should be the same one that was used to call the Initialize method.

This method requires administrative rights to execute successfully. If the user account of the process that calls this method doesn't have such rights, the call will fail with an ERROR_PRIVILEGE_NOT_HELD (0x0522) error. Please refer to the Default Rules topic for more information.

Note: The methods and properties related to rule management are not intended to be used from multiple threads at once. Applications that wish to use said methods and properties from multiple threads (e.g., during the AfterFilterAttachToVolume and AfterFilterDetachFromVolume events) are responsible for employing proper thread synchronization techniques to ensure that manipulation and enumeration of the rule lists both occur in a thread-safe manner.

AddFilterRule Method (CBFilter Component)

This method adds a standard filter rule or access rule.

Syntax

public bool AddFilterRule(string mask, int accessFlags, long controlFlags, long notifyFlags);
Public Function AddFilterRule(ByVal Mask As String, ByVal AccessFlags As Integer, ByVal ControlFlags As Long, ByVal NotifyFlags As Long) As Boolean

Remarks

This method adds a standard filter rule or access rule for the files and directories that match the specified Mask. Each rule in a ruleset is uniquely identified by its mask; if a rule with the specified mask already exists, the new rule's parameters are merged into it.

If the rule is added successfully, this method returns true; otherwise, it returns false.

Standard filter rules determine which filesystem operations, of those performed on matching files and directories, the component should fire its events for. Access rules instruct the component's system driver to apply certain access restrictions to matching files and directories.

The Mask parameter must be a valid file mask according to the File Masks topic. Only the files and directories that match the specified mask will be covered by the rule.

The AccessFlags parameter specifies which access restrictions the component's system driver should apply to matching files and directories. The value passed for this parameter should be constructed by ORing together zero or more of the following flags:

ACCESS_NONE0x00No access restrictions.

ACCESS_READ_ONLY0x01Read-only access; writing and deleting are prohibited.

ACCESS_WRITE_ONLY0x02Write-only access; reading and deleting are prohibited.

ACCESS_DELETE_PROTECT0x04Deleting and renaming are prohibited.

ACCESS_EXECUTE_PROTECT0x08Execution is prohibited.

ACCESS_NO_CHANGE_DAC0x10Change of security attributes is prohibited.

ACCESS_NO_CHANGE_OWNER0x20Change of owner is prohibited.

ACCESS_RENAME_PROTECT0x40Renaming is prohibited.

ACCESS_DELETE_ONLY_PROTECT0x80Deleting is prohibited (renaming is not affected).

ACCESS_REMOTE_ACCESS_PROTECT0x100Access from other systems is prohibited.

ACCESS_DENY_ALL0x200All access is denied.

ACCESS_ALL_FLAGS-1Used to denote all currently set access restriction flags.

The ControlFlags parameter specifies which filesystem operations the component should fire Control Events for. For example, if the FS_CE_BEFORE_READ and FS_CE_AFTER_READ flags are present, the BeforeReadFile and AfterReadFile events will fire before and after a read operation is performed on any file that matches Mask. The value passed for this parameter should be constructed by ORing together zero or more of the following flags:

FS_CE_NONE0Don't fire for any filesystem operations.

Control Events will not fire for any filesystem operations.

FS_CE_BEFORE_CREATE0x000000000001LFire before file creation operations.

The BeforeCreateFile event will fire anytime the OS attempts to create a file or directory. In some cases, this event can cause the BeforeOpenFile event to fire; refer to the File Create/Open Events topic for more information.

FS_CE_AFTER_CREATE0x000000000002LFire after file creation operations.

The AfterCreateFile event will fire after a file or directory creation request has been processed, before the response is returned. In some cases, this event can cause the AfterOpenFile event to fire; refer to the File Create/Open Events topic for more information.

FS_CE_BEFORE_OPEN0x000000000004LFire before file open operations.

The BeforeOpenFile event will fire anytime the OS attempts to open a file or directory. In some cases, this event can cause the BeforeCreateFile event to fire; refer to the File Create/Open Events topic for more information.

FS_CE_AFTER_OPEN0x000000000008LFire after file open operations.

The AfterOpenFile event will fire after a file or directory open request has been processed, before the response is returned. In some cases, this event can cause the AfterCreateFile event to fire; refer to the File Create/Open Events topic for more information.

FS_CE_BEFORE_READ0x000000000010LFire before read operations.

The BeforeReadFile event will fire anytime the OS attempts to read data from a file.

FS_CE_AFTER_READ0x000000000020LFire after read operations.

The AfterReadFile event will fire after a read request has been processed, before the response is returned.

FS_CE_BEFORE_WRITE0x000000000040LFire before write operations.

The BeforeWriteFile event will fire anytime the OS attempts to write data to a file.

FS_CE_AFTER_WRITE0x000000000080LFire after write operations.

The AfterReadFile event will fire after a write request has been processed, before the response is returned.

FS_CE_BEFORE_LOCK_CONTROL0x000000000100LFire before lock and unlock operations.

The BeforeLock, BeforeUnlockAll, BeforeUnlockAllByKey, and BeforeUnlockSingle events will fire, as applicable, before the OS attempts to lock or unlock a range of bytes in a file.

FS_CE_AFTER_LOCK_CONTROL0x000000000200LFire before and after lock and unlock operations.

The AfterLock, AfterUnlockAll, AfterUnlockAllByKey, and AfterUnlockSingle, events will fire, as applicable, after a lock or unlock request has been processed, before the response is returned.

FS_CE_BEFORE_CLEANUP0x000000000400LFire before file handle cleanup operations.

The BeforeCleanupFile event will fire anytime a process closes a file or directory handle.

FS_CE_AFTER_CLEANUP0x000000000800LFire after file handle cleanup operations.

The AfterCleanupFile event will fire after a file handle cleanup request has been processed, before the response is returned.

FS_CE_BEFORE_CLOSE0x000000001000LFire before file close operations.

The BeforeCloseFile event will fire anytime the OS closes a file or directory. Also, the AfterCloseEnumeration event will fire anytime the OS closes a directory enumeration (which typically occurs immediately before the directory is closed).

FS_CE_AFTER_CLOSE0x000000002000LFire after file close operations.

The AfterCloseFile event will fire after a file/directory close request has been processed, before the response is returned.

FS_CE_BEFORE_CAN_DELETE0x000000004000LFire before 'can be deleted' operations.

The BeforeCanFileBeDeleted event will fire anytime the OS checks whether a file or directory can be deleted.

FS_CE_AFTER_CAN_DELETE0x000000008000LFire after 'can be deleted' operations.

The AfterCanFileBeDeleted event will fire after a can be deleted request has been processed, before the response is returned.

FS_CE_BEFORE_DELETE0x000000010000LFire before delete operations

The BeforeDeleteFile event will fire anytime the OS attempts to delete a file or directory.

FS_CE_AFTER_DELETE0x000000020000LFire after delete operations.

The AfterDeleteFile event will fire after a delete request has been processed, before the response is returned.

FS_CE_BEFORE_RENAME0x000000040000LFire before rename/move operations.

The BeforeRenameOrMoveFile event will fire anytime the OS attempts to rename or move a file or directory.

FS_CE_AFTER_RENAME0x000000080000LFire after rename/move operations.

The AfterRenameOrMoveFile event will fire after a rename or move request has been processed, before the response is returned.

FS_CE_BEFORE_GET_SECURITY0x000000100000LFire before get security operations.

The BeforeGetFileSecurity event will fire before the OS queries the security attributes of a file or directory.

FS_CE_AFTER_GET_SECURITY0x000000200000LFire after get security operations.

The AfterGetFileSecurity events will fire after a get security operation has been processed, before the response is returned.

FS_CE_BEFORE_ENUMERATE_DIRECTORY0x000000400000LFire before directory enumeration operations.

The BeforeEnumerateDirectory event will fire anytime the OS needs to read information about directory entries.

FS_CE_AFTER_ENUMERATE_DIRECTORY0x000000800000LFire after directory enumeration operations.

The AfterEnumerateDirectory event will fire after information about a directory entry has been retrieved during directory enumeration, before the response is returned.

FS_CE_BEFORE_QUERY_FILE_INFO0x000001000000LFire before 'query file information' operations.

The BeforeQueryFileInfo event will fire anytime the OS needs to retrieve information about a file or directory.

FS_CE_AFTER_QUERY_FILE_INFO0x000002000000LFire after 'query file information' operations.

The AfterQueryFileInfo event will fire after a file or directory information query request has been processed, before the response is returned.

FS_CE_AFTER_GET_SIZES0x000008000000LFire after get size operations.

The AfterGetFileSizes event will fire after a file's size information is retrieved, before the response is returned.

FS_CE_BEFORE_SET_SECURITY0x000010000000LFire before set security operations.

The BeforeSetFileSecurity event will fire anytime the OS needs to change the security attributes of a file or directory.

FS_CE_AFTER_SET_SECURITY0x000020000000LFire after set security operations.

The AfterSetFileSecurity event will fire after a security attribute change request has been processed, before the response is returned.

FS_CE_BEFORE_SET_ATTRIBUTES0x000040000000LFire before file attribute update operations.

The BeforeSetFileAttributes event will fire anytime the OS attempts to change the attributes of a file or directory.

FS_CE_AFTER_SET_ATTRIBUTES0x000080000000LFire after file attribute update operations.

The AfterSetFileAttributes event will fire after a file attribute change request has been processed, before the response is returned.

FS_CE_BEFORE_SET_SIZES0x000100000000LFire before file resize operations.

The BeforeSetFileSize event will fire anytime the OS attempts to resize a file, and the BeforeSetAllocationSize event will fire anytime the OS attempts to change a file's allocation size.

FS_CE_AFTER_SET_SIZES0x000200000000LFire after file resize operations.

The AfterSetFileSize event will fire after a file resize request has been processed, and the AfterSetAllocationSize event will fire after a file allocation size change request has been processed, before the response is returned.

FS_CE_BEFORE_CREATE_HARD_LINK0x000400000000LFire before hard link creation operations.

The BeforeCreateHardLink event will fire anytime the OS attempts to create a hard link.

FS_CE_AFTER_CREATE_HARD_LINK0x000800000000LFire after hard link creation operations.

The AfterCreateHardLink events will fire after a hard link creation request has been processed, before the response is returned.

FS_CE_BEFORE_FSCTL0x001000000000LFire before FSCTL operations.

The BeforeFsctl event will fire anytime an IRP_MJ_FILE_SYSTEM_CONTROL request occurs.

FS_CE_AFTER_FSCTL0x002000000000LFire after FSCTL operations.

The AfterFsctl event will fire after an IRP_MJ_FILE_SYSTEM_CONTROL request has been processed, before the response is returned.

FS_CE_BEFORE_IOCTL0x004000000000LFire before IOCTL operations.

The BeforeIoctl event will fire anytime an IRP_MJ_DEVICE_CONTROL request occurs.

FS_CE_AFTER_IOCTL0x008000000000LFire after IOCTL operations.

The AfterIoctl event will fire after an IRP_MJ_DEVICE_CONTROL request has been processed, before the response is returned.

FS_CE_BEFORE_SET_FILE_INFO0x010000000000LFire before 'set file information' operations.

The BeforeSetFileInfo event will fire anytime the OS needs to change information about a file or directory.

FS_CE_AFTER_SET_FILE_INFO0x020000000000LFire after 'set file information' operations.

The AfterSetFileInfo event will fire after a file or directory information change request has been processed, before the response is returned.

FS_CE_BEFORE_SET_EA0x040000000000LFire before Set Extended Attributes operations.

The BeforeSetEa event will fire anytime the OS needs to set extended attributes of a file.

FS_CE_AFTER_SET_EA0x080000000000LFire after Set Extended Attributes operations.

The AfterSetEa event will fire after the OS request to set extended attributes of a file has been processed, before the response is returned.

FS_CE_BEFORE_QUERY_EA0x100000000000LFire before Query Extended Attributes operations.

The BeforeQueryEa event will fire anytime the OS needs to retrieve extended attributes of a file.

FS_CE_AFTER_QUERY_EA0x200000000000LFire after Query Extended Attributes operations.

The AfterQueryEa event will fire after the OS request to retrieve extended attributes of a file has been processed, before the response is returned.

FS_CE_BEFORE_GET_REPARSE_POINT0x400000000000LFire before Get Reparse Point operations.

The BeforeGetReparsePoint event will fire anytime the OS needs to read a reparse point of a file or directory.

FS_CE_AFTER_GET_REPARSE_POINT0x800000000000LFire after Get Reparse Point operations.

The AfterGetReparsePoint event will fire after the OS request to read a reparse point of a file or directory has been processed, before the response is returned.

FS_CE_BEFORE_SET_REPARSE_POINT0x1000000000000LFire before Set Reparse Point operations.

The BeforeSetReparsePoint event will fire anytime the OS needs to set or update a reparse point for a file or directory.

FS_CE_AFTER_SET_REPARSE_POINT0x2000000000000LFire after Set Reparse Point operations.

The AfterSetReparsePoint event will fire after the OS request to set or update a reparse point for a file or directory has been processed, before the response is returned.

FS_CE_BEFORE_DELETE_REPARSE_POINT0x4000000000000LFire before Delete Reparse Point operations.

The BeforeDeleteReparsePoint event will fire anytime the OS needs to remove reparse point information from a file or directory.

FS_CE_AFTER_DELETE_REPARSE_POINT0x8000000000000LFire after Delete Reparse Point operations.

The AfterDeleteReparsePoint event will fire after the OS request to remove reparse point information from a file or directory has been processed, before the response is returned.

FS_CE_REPARSE_FILENAME0x40000000000000LFire before various operations for the purpose of file redirection.

The ReparseFileName event will fire before any operation that includes a file or directory name, giving the application a chance to redirect it. This event is typically used when an application requires more advanced redirection logic than Reparse Rules can provide; please refer to that topic for more information.

FS_CE_REPARSE_TAG0x80000000000000LFire for reparse operations.

The ReparseWithTag event will fire anytime a file/directory open operation returns a STATUS_REPARSE result, allowing the application to handle the reparse point. Please refer to Microsoft's Reparse Points article for more information.

FS_CE_ALL-1Fire for all filesystem operations.

Control Events will fire for all filesystem operations that the component tracks.

The NotifyFlags parameter specifies which filesystem operations the component should fire Notification Events for. For example, if the FS_NE_READ flag is present, the NotifyReadFile event will fire after a read operation is performed on any file that matches Mask. The value passed for this parameter should be constructed by ORing together zero or more of the following flags:

FS_NE_NONE0Don't fire for any filesystem operations.

Notification Events will not fire for any filesystem operations.

FS_NE_CREATE0x00000001LFire for file creation operations.

The NotifyCreateFile event will fire anytime the OS creates a file or directory. In some cases, this event can cause the NotifyOpenFile event to fire; refer to the File Create/Open Events topic for more information.

FS_NE_OPEN0x00000002LFire for file open operations.

The NotifyOpenFile event will fire anytime the OS opens a file or directory. In some cases, this event can cause the NotifyCreateFile event to fire; refer to the File Create/Open Events topic for more information.

FS_NE_READ0x00000004LFire for read operations.

The NotifyReadFile event will fire anytime the OS reads data from a file.

FS_NE_WRITE0x00000008LFire for write operations.

The NotifyWriteFile event will fire anytime the OS writes data to a file.

FS_NE_LOCK_CONTROL0x00000010LFire for lock and unlock operations.

The NotifyLock, NotifyUnlockAll, NotifyUnlockAllByKey, and NotifyUnlockSingle events will fire, as applicable, anytime the OS locks or unlocks a range of bytes in a file.

FS_NE_CLEANUP0x00000020LFire for file handle cleanup operations.

The NotifyCleanupFile event will fire anytime a process closes a file or directory handle.

FS_NE_CLOSE0x00000040LFire for file close operations.

The NotifyCloseFile event will fire anytime the OS closes a file or directory.

FS_NE_CAN_DELETE0x00000080LFire for 'can be deleted' operations.

The NotifyCanFileBeDeleted event will fire anytime the OS checks whether or not a file or directory can be deleted.

FS_NE_DELETE0x00000100LFire for delete operations.

The NotifyDeleteFile event will fire anytime the OS deletes a file or directory.

FS_NE_RENAME0x00000200LFire for rename/move operations.

The NotifyRenameOrMoveFile event will fire anytime the OS renames or moves a file or directory.

FS_NE_GET_SECURITY0x00000400LFire for get security operations.

The NotifyGetFileSecurity event will fire anytime the OS queries the security attributes of a file or directory.

FS_NE_ENUMERATE_DIRECTORY0x00000800LFire for directory enumeration operations.

The NotifyEnumerateDirectory event will fire anytime the OS retrieves a directory entry during directory enumeration.

FS_NE_QUERY_FILE_INFO0x00001000LFire for QueryFileInformation operations.

The NotifyQueryFileInfo event will fire anytime the OS retrieves information about a file or directory.

FS_NE_GET_SIZES0x00002000LFire for get size operations.

The NotifyGetFileSizes event will fire anytime the OS retrieves a file's size information.

FS_NE_SET_SECURITY0x00004000LFire for set security operations.

The NotifySetFileSecurity event will fire anytime the OS changes the security attributes of a file or directory.

FS_NE_SET_ATTRIBUTES0x00008000LFire for file attribute update operations.

The NotifySetFileAttributes event will fire anytime the OS changes the attributes of a file or directory.

FS_NE_SET_SIZES0x00010000LFire for file resize operations.

The NotifySetFileSize event will fire anytime the OS resizes a file, and the NotifySetAllocationSize event will fire anytime the OS changes a file's allocation size.

FS_NE_CREATE_HARD_LINK0x00020000LFire for hard link creation operations.

The NotifyCreateHardLink event will fire anytime the OS creates a hard link.

FS_NE_FSCTL0x00040000LFire for FSCTL operations.

The NotifyFsctl event will fire anytime an IRP_MJ_FILE_SYSTEM_CONTROL operation occurs.

FS_NE_IOCTL0x00080000LFire for IOCTL operations.

The NotifyIoctl event will fire anytime an IRP_MJ_DEVICE_CONTROL operation occurs.

FS_NE_SET_FILE_INFO0x00100000LFire for SetFileInformation operations.

The NotifySetFileInfo event will fire anytime the OS changes information about a file or directory.

FS_NE_SET_EA0x00200000LFire for Set Extended Attributes operations.

The NotifySetEa event will fire anytime the OS sets extended attributes of a file.

FS_NE_QUERY_EA0x00400000LFire for Query Extended Attributes operations.

The NotifyQueryEa event will fire anytime the OS retrieves extended attributes of a file.

FS_NE_GET_REPARSE_POINT0x00800000LFire for Get Reparse Point operations.

The NotifyGetReparsePoint event will fire anytime the OS reads reparse point information of a file or directory.

FS_NE_SET_REPARSE_POINT0x01000000LFire for Set Reparse Point operations.

The NotifySetReparsePoint event will fire anytime the OS sets or updates reparse point information for a file or directory.

FS_NE_DELETE_REPARSE_POINT0x02000000LFire for Delete Reparse Point operations.

The NotifyDeleteReparsePoint event will fire anytime the OS deletes reparse point information from a file or directory.

FS_NE_ALL-1Fire for all filesystem operations.

Notification Events will fire for all filesystem operations that the component tracks.

Note: The methods and properties related to rule management are not intended to be used from multiple threads at once. Applications that wish to use said methods and properties from multiple threads (e.g., during the AfterFilterAttachToVolume and AfterFilterDetachFromVolume events) are responsible for employing proper thread synchronization techniques to ensure that manipulation and enumeration of the rule lists both occur in a thread-safe manner.

AddFilterRuleEx Method (CBFilter Component)

This method adds a standard filter rule or access rule with additional match qualifiers.

Syntax

public bool AddFilterRuleEx(string mask, string eaName, int accessFlags, long controlFlags, long notifyFlags, long minSize, long maxSize, long includedAttributes, long excludedAttributes);
Public Function AddFilterRuleEx(ByVal Mask As String, ByVal EaName As String, ByVal AccessFlags As Integer, ByVal ControlFlags As Long, ByVal NotifyFlags As Long, ByVal MinSize As Long, ByVal MaxSize As Long, ByVal IncludedAttributes As Long, ByVal ExcludedAttributes As Long) As Boolean

Remarks

This method adds a standard filter rule or access rule for the files and directories that match the specified Mask (which must be provided), and other qualifiers (which are optional). Each rule in a ruleset is uniquely identified by its mask; if a rule with the specified mask already exists, the new rule's parameters are merged into it.

If the rule is added successfully, this method returns true; otherwise, it returns false.

Standard filter rules determine which filesystem operations, of those performed on matching files and directories, the component should fire its events for. Access rules instruct the component's system driver to apply certain access restrictions to matching files and directories.

The Mask parameter must be a valid file mask according to the File Masks topic. Only the files and directories that match the specified mask will be covered by the rule.

The EaName parameter specifies the name of an extended attribute that a file or directory must have to qualify as a match; wildcards are not allowed. Pass an empty string if this parameter should not be used as a match qualifier.

The AccessFlags parameter specifies which access restrictions the component's system driver should apply to matching files and directories. The value passed for this parameter should be constructed by ORing together zero or more of the following flags:

ACCESS_NONE0x00No access restrictions.

ACCESS_READ_ONLY0x01Read-only access; writing and deleting are prohibited.

ACCESS_WRITE_ONLY0x02Write-only access; reading and deleting are prohibited.

ACCESS_DELETE_PROTECT0x04Deleting and renaming are prohibited.

ACCESS_EXECUTE_PROTECT0x08Execution is prohibited.

ACCESS_NO_CHANGE_DAC0x10Change of security attributes is prohibited.

ACCESS_NO_CHANGE_OWNER0x20Change of owner is prohibited.

ACCESS_RENAME_PROTECT0x40Renaming is prohibited.

ACCESS_DELETE_ONLY_PROTECT0x80Deleting is prohibited (renaming is not affected).

ACCESS_REMOTE_ACCESS_PROTECT0x100Access from other systems is prohibited.

ACCESS_DENY_ALL0x200All access is denied.

ACCESS_ALL_FLAGS-1Used to denote all currently set access restriction flags.

The ControlFlags parameter specifies which filesystem operations the component should fire Control Events for. For example, if the FS_CE_BEFORE_READ and FS_CE_AFTER_READ flags are present, the BeforeReadFile and AfterReadFile events will fire before and after a read operation is performed on any file that matches Mask. The value passed for this parameter should be constructed by ORing together zero or more of the following flags:

FS_CE_NONE0Don't fire for any filesystem operations.

Control Events will not fire for any filesystem operations.

FS_CE_BEFORE_CREATE0x000000000001LFire before file creation operations.

The BeforeCreateFile event will fire anytime the OS attempts to create a file or directory. In some cases, this event can cause the BeforeOpenFile event to fire; refer to the File Create/Open Events topic for more information.

FS_CE_AFTER_CREATE0x000000000002LFire after file creation operations.

The AfterCreateFile event will fire after a file or directory creation request has been processed, before the response is returned. In some cases, this event can cause the AfterOpenFile event to fire; refer to the File Create/Open Events topic for more information.

FS_CE_BEFORE_OPEN0x000000000004LFire before file open operations.

The BeforeOpenFile event will fire anytime the OS attempts to open a file or directory. In some cases, this event can cause the BeforeCreateFile event to fire; refer to the File Create/Open Events topic for more information.

FS_CE_AFTER_OPEN0x000000000008LFire after file open operations.

The AfterOpenFile event will fire after a file or directory open request has been processed, before the response is returned. In some cases, this event can cause the AfterCreateFile event to fire; refer to the File Create/Open Events topic for more information.

FS_CE_BEFORE_READ0x000000000010LFire before read operations.

The BeforeReadFile event will fire anytime the OS attempts to read data from a file.

FS_CE_AFTER_READ0x000000000020LFire after read operations.

The AfterReadFile event will fire after a read request has been processed, before the response is returned.

FS_CE_BEFORE_WRITE0x000000000040LFire before write operations.

The BeforeWriteFile event will fire anytime the OS attempts to write data to a file.

FS_CE_AFTER_WRITE0x000000000080LFire after write operations.

The AfterReadFile event will fire after a write request has been processed, before the response is returned.

FS_CE_BEFORE_LOCK_CONTROL0x000000000100LFire before lock and unlock operations.

The BeforeLock, BeforeUnlockAll, BeforeUnlockAllByKey, and BeforeUnlockSingle events will fire, as applicable, before the OS attempts to lock or unlock a range of bytes in a file.

FS_CE_AFTER_LOCK_CONTROL0x000000000200LFire before and after lock and unlock operations.

The AfterLock, AfterUnlockAll, AfterUnlockAllByKey, and AfterUnlockSingle, events will fire, as applicable, after a lock or unlock request has been processed, before the response is returned.

FS_CE_BEFORE_CLEANUP0x000000000400LFire before file handle cleanup operations.

The BeforeCleanupFile event will fire anytime a process closes a file or directory handle.

FS_CE_AFTER_CLEANUP0x000000000800LFire after file handle cleanup operations.

The AfterCleanupFile event will fire after a file handle cleanup request has been processed, before the response is returned.

FS_CE_BEFORE_CLOSE0x000000001000LFire before file close operations.

The BeforeCloseFile event will fire anytime the OS closes a file or directory. Also, the AfterCloseEnumeration event will fire anytime the OS closes a directory enumeration (which typically occurs immediately before the directory is closed).

FS_CE_AFTER_CLOSE0x000000002000LFire after file close operations.

The AfterCloseFile event will fire after a file/directory close request has been processed, before the response is returned.

FS_CE_BEFORE_CAN_DELETE0x000000004000LFire before 'can be deleted' operations.

The BeforeCanFileBeDeleted event will fire anytime the OS checks whether a file or directory can be deleted.

FS_CE_AFTER_CAN_DELETE0x000000008000LFire after 'can be deleted' operations.

The AfterCanFileBeDeleted event will fire after a can be deleted request has been processed, before the response is returned.

FS_CE_BEFORE_DELETE0x000000010000LFire before delete operations

The BeforeDeleteFile event will fire anytime the OS attempts to delete a file or directory.

FS_CE_AFTER_DELETE0x000000020000LFire after delete operations.

The AfterDeleteFile event will fire after a delete request has been processed, before the response is returned.

FS_CE_BEFORE_RENAME0x000000040000LFire before rename/move operations.

The BeforeRenameOrMoveFile event will fire anytime the OS attempts to rename or move a file or directory.

FS_CE_AFTER_RENAME0x000000080000LFire after rename/move operations.

The AfterRenameOrMoveFile event will fire after a rename or move request has been processed, before the response is returned.

FS_CE_BEFORE_GET_SECURITY0x000000100000LFire before get security operations.

The BeforeGetFileSecurity event will fire before the OS queries the security attributes of a file or directory.

FS_CE_AFTER_GET_SECURITY0x000000200000LFire after get security operations.

The AfterGetFileSecurity events will fire after a get security operation has been processed, before the response is returned.

FS_CE_BEFORE_ENUMERATE_DIRECTORY0x000000400000LFire before directory enumeration operations.

The BeforeEnumerateDirectory event will fire anytime the OS needs to read information about directory entries.

FS_CE_AFTER_ENUMERATE_DIRECTORY0x000000800000LFire after directory enumeration operations.

The AfterEnumerateDirectory event will fire after information about a directory entry has been retrieved during directory enumeration, before the response is returned.

FS_CE_BEFORE_QUERY_FILE_INFO0x000001000000LFire before 'query file information' operations.

The BeforeQueryFileInfo event will fire anytime the OS needs to retrieve information about a file or directory.

FS_CE_AFTER_QUERY_FILE_INFO0x000002000000LFire after 'query file information' operations.

The AfterQueryFileInfo event will fire after a file or directory information query request has been processed, before the response is returned.

FS_CE_AFTER_GET_SIZES0x000008000000LFire after get size operations.

The AfterGetFileSizes event will fire after a file's size information is retrieved, before the response is returned.

FS_CE_BEFORE_SET_SECURITY0x000010000000LFire before set security operations.

The BeforeSetFileSecurity event will fire anytime the OS needs to change the security attributes of a file or directory.

FS_CE_AFTER_SET_SECURITY0x000020000000LFire after set security operations.

The AfterSetFileSecurity event will fire after a security attribute change request has been processed, before the response is returned.

FS_CE_BEFORE_SET_ATTRIBUTES0x000040000000LFire before file attribute update operations.

The BeforeSetFileAttributes event will fire anytime the OS attempts to change the attributes of a file or directory.

FS_CE_AFTER_SET_ATTRIBUTES0x000080000000LFire after file attribute update operations.

The AfterSetFileAttributes event will fire after a file attribute change request has been processed, before the response is returned.

FS_CE_BEFORE_SET_SIZES0x000100000000LFire before file resize operations.

The BeforeSetFileSize event will fire anytime the OS attempts to resize a file, and the BeforeSetAllocationSize event will fire anytime the OS attempts to change a file's allocation size.

FS_CE_AFTER_SET_SIZES0x000200000000LFire after file resize operations.

The AfterSetFileSize event will fire after a file resize request has been processed, and the AfterSetAllocationSize event will fire after a file allocation size change request has been processed, before the response is returned.

FS_CE_BEFORE_CREATE_HARD_LINK0x000400000000LFire before hard link creation operations.

The BeforeCreateHardLink event will fire anytime the OS attempts to create a hard link.

FS_CE_AFTER_CREATE_HARD_LINK0x000800000000LFire after hard link creation operations.

The AfterCreateHardLink events will fire after a hard link creation request has been processed, before the response is returned.

FS_CE_BEFORE_FSCTL0x001000000000LFire before FSCTL operations.

The BeforeFsctl event will fire anytime an IRP_MJ_FILE_SYSTEM_CONTROL request occurs.

FS_CE_AFTER_FSCTL0x002000000000LFire after FSCTL operations.

The AfterFsctl event will fire after an IRP_MJ_FILE_SYSTEM_CONTROL request has been processed, before the response is returned.

FS_CE_BEFORE_IOCTL0x004000000000LFire before IOCTL operations.

The BeforeIoctl event will fire anytime an IRP_MJ_DEVICE_CONTROL request occurs.

FS_CE_AFTER_IOCTL0x008000000000LFire after IOCTL operations.

The AfterIoctl event will fire after an IRP_MJ_DEVICE_CONTROL request has been processed, before the response is returned.

FS_CE_BEFORE_SET_FILE_INFO0x010000000000LFire before 'set file information' operations.

The BeforeSetFileInfo event will fire anytime the OS needs to change information about a file or directory.

FS_CE_AFTER_SET_FILE_INFO0x020000000000LFire after 'set file information' operations.

The AfterSetFileInfo event will fire after a file or directory information change request has been processed, before the response is returned.

FS_CE_BEFORE_SET_EA0x040000000000LFire before Set Extended Attributes operations.

The BeforeSetEa event will fire anytime the OS needs to set extended attributes of a file.

FS_CE_AFTER_SET_EA0x080000000000LFire after Set Extended Attributes operations.

The AfterSetEa event will fire after the OS request to set extended attributes of a file has been processed, before the response is returned.

FS_CE_BEFORE_QUERY_EA0x100000000000LFire before Query Extended Attributes operations.

The BeforeQueryEa event will fire anytime the OS needs to retrieve extended attributes of a file.

FS_CE_AFTER_QUERY_EA0x200000000000LFire after Query Extended Attributes operations.

The AfterQueryEa event will fire after the OS request to retrieve extended attributes of a file has been processed, before the response is returned.

FS_CE_BEFORE_GET_REPARSE_POINT0x400000000000LFire before Get Reparse Point operations.

The BeforeGetReparsePoint event will fire anytime the OS needs to read a reparse point of a file or directory.

FS_CE_AFTER_GET_REPARSE_POINT0x800000000000LFire after Get Reparse Point operations.

The AfterGetReparsePoint event will fire after the OS request to read a reparse point of a file or directory has been processed, before the response is returned.

FS_CE_BEFORE_SET_REPARSE_POINT0x1000000000000LFire before Set Reparse Point operations.

The BeforeSetReparsePoint event will fire anytime the OS needs to set or update a reparse point for a file or directory.

FS_CE_AFTER_SET_REPARSE_POINT0x2000000000000LFire after Set Reparse Point operations.

The AfterSetReparsePoint event will fire after the OS request to set or update a reparse point for a file or directory has been processed, before the response is returned.

FS_CE_BEFORE_DELETE_REPARSE_POINT0x4000000000000LFire before Delete Reparse Point operations.

The BeforeDeleteReparsePoint event will fire anytime the OS needs to remove reparse point information from a file or directory.

FS_CE_AFTER_DELETE_REPARSE_POINT0x8000000000000LFire after Delete Reparse Point operations.

The AfterDeleteReparsePoint event will fire after the OS request to remove reparse point information from a file or directory has been processed, before the response is returned.

FS_CE_REPARSE_FILENAME0x40000000000000LFire before various operations for the purpose of file redirection.

The ReparseFileName event will fire before any operation that includes a file or directory name, giving the application a chance to redirect it. This event is typically used when an application requires more advanced redirection logic than Reparse Rules can provide; please refer to that topic for more information.

FS_CE_REPARSE_TAG0x80000000000000LFire for reparse operations.

The ReparseWithTag event will fire anytime a file/directory open operation returns a STATUS_REPARSE result, allowing the application to handle the reparse point. Please refer to Microsoft's Reparse Points article for more information.

FS_CE_ALL-1Fire for all filesystem operations.

Control Events will fire for all filesystem operations that the component tracks.

The NotifyFlags parameter specifies which filesystem operations the component should fire Notification Events for. For example, if the FS_NE_READ flag is present, the NotifyReadFile event will fire after a read operation is performed on any file that matches Mask. The value passed for this parameter should be constructed by ORing together zero or more of the following flags:

FS_NE_NONE0Don't fire for any filesystem operations.

Notification Events will not fire for any filesystem operations.

FS_NE_CREATE0x00000001LFire for file creation operations.

The NotifyCreateFile event will fire anytime the OS creates a file or directory. In some cases, this event can cause the NotifyOpenFile event to fire; refer to the File Create/Open Events topic for more information.

FS_NE_OPEN0x00000002LFire for file open operations.

The NotifyOpenFile event will fire anytime the OS opens a file or directory. In some cases, this event can cause the NotifyCreateFile event to fire; refer to the File Create/Open Events topic for more information.

FS_NE_READ0x00000004LFire for read operations.

The NotifyReadFile event will fire anytime the OS reads data from a file.

FS_NE_WRITE0x00000008LFire for write operations.

The NotifyWriteFile event will fire anytime the OS writes data to a file.

FS_NE_LOCK_CONTROL0x00000010LFire for lock and unlock operations.

The NotifyLock, NotifyUnlockAll, NotifyUnlockAllByKey, and NotifyUnlockSingle events will fire, as applicable, anytime the OS locks or unlocks a range of bytes in a file.

FS_NE_CLEANUP0x00000020LFire for file handle cleanup operations.

The NotifyCleanupFile event will fire anytime a process closes a file or directory handle.

FS_NE_CLOSE0x00000040LFire for file close operations.

The NotifyCloseFile event will fire anytime the OS closes a file or directory.

FS_NE_CAN_DELETE0x00000080LFire for 'can be deleted' operations.

The NotifyCanFileBeDeleted event will fire anytime the OS checks whether or not a file or directory can be deleted.

FS_NE_DELETE0x00000100LFire for delete operations.

The NotifyDeleteFile event will fire anytime the OS deletes a file or directory.

FS_NE_RENAME0x00000200LFire for rename/move operations.

The NotifyRenameOrMoveFile event will fire anytime the OS renames or moves a file or directory.

FS_NE_GET_SECURITY0x00000400LFire for get security operations.

The NotifyGetFileSecurity event will fire anytime the OS queries the security attributes of a file or directory.

FS_NE_ENUMERATE_DIRECTORY0x00000800LFire for directory enumeration operations.

The NotifyEnumerateDirectory event will fire anytime the OS retrieves a directory entry during directory enumeration.

FS_NE_QUERY_FILE_INFO0x00001000LFire for QueryFileInformation operations.

The NotifyQueryFileInfo event will fire anytime the OS retrieves information about a file or directory.

FS_NE_GET_SIZES0x00002000LFire for get size operations.

The NotifyGetFileSizes event will fire anytime the OS retrieves a file's size information.

FS_NE_SET_SECURITY0x00004000LFire for set security operations.

The NotifySetFileSecurity event will fire anytime the OS changes the security attributes of a file or directory.

FS_NE_SET_ATTRIBUTES0x00008000LFire for file attribute update operations.

The NotifySetFileAttributes event will fire anytime the OS changes the attributes of a file or directory.

FS_NE_SET_SIZES0x00010000LFire for file resize operations.

The NotifySetFileSize event will fire anytime the OS resizes a file, and the NotifySetAllocationSize event will fire anytime the OS changes a file's allocation size.

FS_NE_CREATE_HARD_LINK0x00020000LFire for hard link creation operations.

The NotifyCreateHardLink event will fire anytime the OS creates a hard link.

FS_NE_FSCTL0x00040000LFire for FSCTL operations.

The NotifyFsctl event will fire anytime an IRP_MJ_FILE_SYSTEM_CONTROL operation occurs.

FS_NE_IOCTL0x00080000LFire for IOCTL operations.

The NotifyIoctl event will fire anytime an IRP_MJ_DEVICE_CONTROL operation occurs.

FS_NE_SET_FILE_INFO0x00100000LFire for SetFileInformation operations.

The NotifySetFileInfo event will fire anytime the OS changes information about a file or directory.

FS_NE_SET_EA0x00200000LFire for Set Extended Attributes operations.

The NotifySetEa event will fire anytime the OS sets extended attributes of a file.

FS_NE_QUERY_EA0x00400000LFire for Query Extended Attributes operations.

The NotifyQueryEa event will fire anytime the OS retrieves extended attributes of a file.

FS_NE_GET_REPARSE_POINT0x00800000LFire for Get Reparse Point operations.

The NotifyGetReparsePoint event will fire anytime the OS reads reparse point information of a file or directory.

FS_NE_SET_REPARSE_POINT0x01000000LFire for Set Reparse Point operations.

The NotifySetReparsePoint event will fire anytime the OS sets or updates reparse point information for a file or directory.

FS_NE_DELETE_REPARSE_POINT0x02000000LFire for Delete Reparse Point operations.

The NotifyDeleteReparsePoint event will fire anytime the OS deletes reparse point information from a file or directory.

FS_NE_ALL-1Fire for all filesystem operations.

Notification Events will fire for all filesystem operations that the component tracks.

The MinSize and MaxSize parameters specify the minimum and maximum size, in bytes, that a file can be to qualify as a match. Pass -1 for either parameter if it should not be used as a match qualifier.

The IncludedAttributes and ExcludedAttributes parameters specify which file attributes a file or directory must have or not have to qualify as a match. Pass 0 for either parameter if it should not be used as a match qualifier.

Note: The methods and properties related to rule management are not intended to be used from multiple threads at once. Applications that wish to use said methods and properties from multiple threads (e.g., during the AfterFilterAttachToVolume and AfterFilterDetachFromVolume events) are responsible for employing proper thread synchronization techniques to ensure that manipulation and enumeration of the rule lists both occur in a thread-safe manner.

AddPassthroughRule Method (CBFilter Component)

This method adds a passthrough rule.

Syntax

public bool AddPassthroughRule(string mask, int accessFlags, long controlFlags, long notifyFlags);
Public Function AddPassthroughRule(ByVal Mask As String, ByVal AccessFlags As Integer, ByVal ControlFlags As Long, ByVal NotifyFlags As Long) As Boolean

Remarks

This method adds a passthrough rule for the files and directories that match the specified Mask. Each rule in a ruleset is uniquely identified by its mask; if a rule with the specified mask already exists, the new rule's parameters are merged into it.

If the rule is added successfully, this method returns true; otherwise, it returns false.

Passthrough rules exclude matching files and directories from being processed by other filter rules.

The Mask parameter must be a valid file mask according to the File Masks topic. Only the files and directories that match the specified mask will be covered by the rule.

The AccessFlags parameter specifies which access restrictions the component's system driver should lift from matching files and directories. The value passed for this parameter should be constructed by ORing together zero or more of the following flags:

ACCESS_NONE0x00No access restrictions.

ACCESS_READ_ONLY0x01Read-only access; writing and deleting are prohibited.

ACCESS_WRITE_ONLY0x02Write-only access; reading and deleting are prohibited.

ACCESS_DELETE_PROTECT0x04Deleting and renaming are prohibited.

ACCESS_EXECUTE_PROTECT0x08Execution is prohibited.

ACCESS_NO_CHANGE_DAC0x10Change of security attributes is prohibited.

ACCESS_NO_CHANGE_OWNER0x20Change of owner is prohibited.

ACCESS_RENAME_PROTECT0x40Renaming is prohibited.

ACCESS_DELETE_ONLY_PROTECT0x80Deleting is prohibited (renaming is not affected).

ACCESS_REMOTE_ACCESS_PROTECT0x100Access from other systems is prohibited.

ACCESS_DENY_ALL0x200All access is denied.

ACCESS_ALL_FLAGS-1Used to denote all currently set access restriction flags.

The ControlFlags parameter specifies which filesystem operations the component should not fire Control Events for. The value passed for this parameter should be constructed by ORing together zero or more of the following flags:

FS_CE_NONE0Don't fire for any filesystem operations.

Control Events will not fire for any filesystem operations.

FS_CE_BEFORE_CREATE0x000000000001LFire before file creation operations.

The BeforeCreateFile event will fire anytime the OS attempts to create a file or directory. In some cases, this event can cause the BeforeOpenFile event to fire; refer to the File Create/Open Events topic for more information.

FS_CE_AFTER_CREATE0x000000000002LFire after file creation operations.

The AfterCreateFile event will fire after a file or directory creation request has been processed, before the response is returned. In some cases, this event can cause the AfterOpenFile event to fire; refer to the File Create/Open Events topic for more information.

FS_CE_BEFORE_OPEN0x000000000004LFire before file open operations.

The BeforeOpenFile event will fire anytime the OS attempts to open a file or directory. In some cases, this event can cause the BeforeCreateFile event to fire; refer to the File Create/Open Events topic for more information.

FS_CE_AFTER_OPEN0x000000000008LFire after file open operations.

The AfterOpenFile event will fire after a file or directory open request has been processed, before the response is returned. In some cases, this event can cause the AfterCreateFile event to fire; refer to the File Create/Open Events topic for more information.

FS_CE_BEFORE_READ0x000000000010LFire before read operations.

The BeforeReadFile event will fire anytime the OS attempts to read data from a file.

FS_CE_AFTER_READ0x000000000020LFire after read operations.

The AfterReadFile event will fire after a read request has been processed, before the response is returned.

FS_CE_BEFORE_WRITE0x000000000040LFire before write operations.

The BeforeWriteFile event will fire anytime the OS attempts to write data to a file.

FS_CE_AFTER_WRITE0x000000000080LFire after write operations.

The AfterReadFile event will fire after a write request has been processed, before the response is returned.

FS_CE_BEFORE_LOCK_CONTROL0x000000000100LFire before lock and unlock operations.

The BeforeLock, BeforeUnlockAll, BeforeUnlockAllByKey, and BeforeUnlockSingle events will fire, as applicable, before the OS attempts to lock or unlock a range of bytes in a file.

FS_CE_AFTER_LOCK_CONTROL0x000000000200LFire before and after lock and unlock operations.

The AfterLock, AfterUnlockAll, AfterUnlockAllByKey, and AfterUnlockSingle, events will fire, as applicable, after a lock or unlock request has been processed, before the response is returned.

FS_CE_BEFORE_CLEANUP0x000000000400LFire before file handle cleanup operations.

The BeforeCleanupFile event will fire anytime a process closes a file or directory handle.

FS_CE_AFTER_CLEANUP0x000000000800LFire after file handle cleanup operations.

The AfterCleanupFile event will fire after a file handle cleanup request has been processed, before the response is returned.

FS_CE_BEFORE_CLOSE0x000000001000LFire before file close operations.

The BeforeCloseFile event will fire anytime the OS closes a file or directory. Also, the AfterCloseEnumeration event will fire anytime the OS closes a directory enumeration (which typically occurs immediately before the directory is closed).

FS_CE_AFTER_CLOSE0x000000002000LFire after file close operations.

The AfterCloseFile event will fire after a file/directory close request has been processed, before the response is returned.

FS_CE_BEFORE_CAN_DELETE0x000000004000LFire before 'can be deleted' operations.

The BeforeCanFileBeDeleted event will fire anytime the OS checks whether a file or directory can be deleted.

FS_CE_AFTER_CAN_DELETE0x000000008000LFire after 'can be deleted' operations.

The AfterCanFileBeDeleted event will fire after a can be deleted request has been processed, before the response is returned.

FS_CE_BEFORE_DELETE0x000000010000LFire before delete operations

The BeforeDeleteFile event will fire anytime the OS attempts to delete a file or directory.

FS_CE_AFTER_DELETE0x000000020000LFire after delete operations.

The AfterDeleteFile event will fire after a delete request has been processed, before the response is returned.

FS_CE_BEFORE_RENAME0x000000040000LFire before rename/move operations.

The BeforeRenameOrMoveFile event will fire anytime the OS attempts to rename or move a file or directory.

FS_CE_AFTER_RENAME0x000000080000LFire after rename/move operations.

The AfterRenameOrMoveFile event will fire after a rename or move request has been processed, before the response is returned.

FS_CE_BEFORE_GET_SECURITY0x000000100000LFire before get security operations.

The BeforeGetFileSecurity event will fire before the OS queries the security attributes of a file or directory.

FS_CE_AFTER_GET_SECURITY0x000000200000LFire after get security operations.

The AfterGetFileSecurity events will fire after a get security operation has been processed, before the response is returned.

FS_CE_BEFORE_ENUMERATE_DIRECTORY0x000000400000LFire before directory enumeration operations.

The BeforeEnumerateDirectory event will fire anytime the OS needs to read information about directory entries.

FS_CE_AFTER_ENUMERATE_DIRECTORY0x000000800000LFire after directory enumeration operations.

The AfterEnumerateDirectory event will fire after information about a directory entry has been retrieved during directory enumeration, before the response is returned.

FS_CE_BEFORE_QUERY_FILE_INFO0x000001000000LFire before 'query file information' operations.

The BeforeQueryFileInfo event will fire anytime the OS needs to retrieve information about a file or directory.

FS_CE_AFTER_QUERY_FILE_INFO0x000002000000LFire after 'query file information' operations.

The AfterQueryFileInfo event will fire after a file or directory information query request has been processed, before the response is returned.

FS_CE_AFTER_GET_SIZES0x000008000000LFire after get size operations.

The AfterGetFileSizes event will fire after a file's size information is retrieved, before the response is returned.

FS_CE_BEFORE_SET_SECURITY0x000010000000LFire before set security operations.

The BeforeSetFileSecurity event will fire anytime the OS needs to change the security attributes of a file or directory.

FS_CE_AFTER_SET_SECURITY0x000020000000LFire after set security operations.

The AfterSetFileSecurity event will fire after a security attribute change request has been processed, before the response is returned.

FS_CE_BEFORE_SET_ATTRIBUTES0x000040000000LFire before file attribute update operations.

The BeforeSetFileAttributes event will fire anytime the OS attempts to change the attributes of a file or directory.

FS_CE_AFTER_SET_ATTRIBUTES0x000080000000LFire after file attribute update operations.

The AfterSetFileAttributes event will fire after a file attribute change request has been processed, before the response is returned.

FS_CE_BEFORE_SET_SIZES0x000100000000LFire before file resize operations.

The BeforeSetFileSize event will fire anytime the OS attempts to resize a file, and the BeforeSetAllocationSize event will fire anytime the OS attempts to change a file's allocation size.

FS_CE_AFTER_SET_SIZES0x000200000000LFire after file resize operations.

The AfterSetFileSize event will fire after a file resize request has been processed, and the AfterSetAllocationSize event will fire after a file allocation size change request has been processed, before the response is returned.

FS_CE_BEFORE_CREATE_HARD_LINK0x000400000000LFire before hard link creation operations.

The BeforeCreateHardLink event will fire anytime the OS attempts to create a hard link.

FS_CE_AFTER_CREATE_HARD_LINK0x000800000000LFire after hard link creation operations.

The AfterCreateHardLink events will fire after a hard link creation request has been processed, before the response is returned.

FS_CE_BEFORE_FSCTL0x001000000000LFire before FSCTL operations.

The BeforeFsctl event will fire anytime an IRP_MJ_FILE_SYSTEM_CONTROL request occurs.

FS_CE_AFTER_FSCTL0x002000000000LFire after FSCTL operations.

The AfterFsctl event will fire after an IRP_MJ_FILE_SYSTEM_CONTROL request has been processed, before the response is returned.

FS_CE_BEFORE_IOCTL0x004000000000LFire before IOCTL operations.

The BeforeIoctl event will fire anytime an IRP_MJ_DEVICE_CONTROL request occurs.

FS_CE_AFTER_IOCTL0x008000000000LFire after IOCTL operations.

The AfterIoctl event will fire after an IRP_MJ_DEVICE_CONTROL request has been processed, before the response is returned.

FS_CE_BEFORE_SET_FILE_INFO0x010000000000LFire before 'set file information' operations.

The BeforeSetFileInfo event will fire anytime the OS needs to change information about a file or directory.

FS_CE_AFTER_SET_FILE_INFO0x020000000000LFire after 'set file information' operations.

The AfterSetFileInfo event will fire after a file or directory information change request has been processed, before the response is returned.

FS_CE_BEFORE_SET_EA0x040000000000LFire before Set Extended Attributes operations.

The BeforeSetEa event will fire anytime the OS needs to set extended attributes of a file.

FS_CE_AFTER_SET_EA0x080000000000LFire after Set Extended Attributes operations.

The AfterSetEa event will fire after the OS request to set extended attributes of a file has been processed, before the response is returned.

FS_CE_BEFORE_QUERY_EA0x100000000000LFire before Query Extended Attributes operations.

The BeforeQueryEa event will fire anytime the OS needs to retrieve extended attributes of a file.

FS_CE_AFTER_QUERY_EA0x200000000000LFire after Query Extended Attributes operations.

The AfterQueryEa event will fire after the OS request to retrieve extended attributes of a file has been processed, before the response is returned.

FS_CE_BEFORE_GET_REPARSE_POINT0x400000000000LFire before Get Reparse Point operations.

The BeforeGetReparsePoint event will fire anytime the OS needs to read a reparse point of a file or directory.

FS_CE_AFTER_GET_REPARSE_POINT0x800000000000LFire after Get Reparse Point operations.

The AfterGetReparsePoint event will fire after the OS request to read a reparse point of a file or directory has been processed, before the response is returned.

FS_CE_BEFORE_SET_REPARSE_POINT0x1000000000000LFire before Set Reparse Point operations.

The BeforeSetReparsePoint event will fire anytime the OS needs to set or update a reparse point for a file or directory.

FS_CE_AFTER_SET_REPARSE_POINT0x2000000000000LFire after Set Reparse Point operations.

The AfterSetReparsePoint event will fire after the OS request to set or update a reparse point for a file or directory has been processed, before the response is returned.

FS_CE_BEFORE_DELETE_REPARSE_POINT0x4000000000000LFire before Delete Reparse Point operations.

The BeforeDeleteReparsePoint event will fire anytime the OS needs to remove reparse point information from a file or directory.

FS_CE_AFTER_DELETE_REPARSE_POINT0x8000000000000LFire after Delete Reparse Point operations.

The AfterDeleteReparsePoint event will fire after the OS request to remove reparse point information from a file or directory has been processed, before the response is returned.

FS_CE_REPARSE_FILENAME0x40000000000000LFire before various operations for the purpose of file redirection.

The ReparseFileName event will fire before any operation that includes a file or directory name, giving the application a chance to redirect it. This event is typically used when an application requires more advanced redirection logic than Reparse Rules can provide; please refer to that topic for more information.

FS_CE_REPARSE_TAG0x80000000000000LFire for reparse operations.

The ReparseWithTag event will fire anytime a file/directory open operation returns a STATUS_REPARSE result, allowing the application to handle the reparse point. Please refer to Microsoft's Reparse Points article for more information.

FS_CE_ALL-1Fire for all filesystem operations.

Control Events will fire for all filesystem operations that the component tracks.

The NotifyFlags parameter specifies which filesystem operations the component should not fire Notification Events for. The value passed for this parameter should be constructed by ORing together zero or more of the following flags:

FS_NE_NONE0Don't fire for any filesystem operations.

Notification Events will not fire for any filesystem operations.

FS_NE_CREATE0x00000001LFire for file creation operations.

The NotifyCreateFile event will fire anytime the OS creates a file or directory. In some cases, this event can cause the NotifyOpenFile event to fire; refer to the File Create/Open Events topic for more information.

FS_NE_OPEN0x00000002LFire for file open operations.

The NotifyOpenFile event will fire anytime the OS opens a file or directory. In some cases, this event can cause the NotifyCreateFile event to fire; refer to the File Create/Open Events topic for more information.

FS_NE_READ0x00000004LFire for read operations.

The NotifyReadFile event will fire anytime the OS reads data from a file.

FS_NE_WRITE0x00000008LFire for write operations.

The NotifyWriteFile event will fire anytime the OS writes data to a file.

FS_NE_LOCK_CONTROL0x00000010LFire for lock and unlock operations.

The NotifyLock, NotifyUnlockAll, NotifyUnlockAllByKey, and NotifyUnlockSingle events will fire, as applicable, anytime the OS locks or unlocks a range of bytes in a file.

FS_NE_CLEANUP0x00000020LFire for file handle cleanup operations.

The NotifyCleanupFile event will fire anytime a process closes a file or directory handle.

FS_NE_CLOSE0x00000040LFire for file close operations.

The NotifyCloseFile event will fire anytime the OS closes a file or directory.

FS_NE_CAN_DELETE0x00000080LFire for 'can be deleted' operations.

The NotifyCanFileBeDeleted event will fire anytime the OS checks whether or not a file or directory can be deleted.

FS_NE_DELETE0x00000100LFire for delete operations.

The NotifyDeleteFile event will fire anytime the OS deletes a file or directory.

FS_NE_RENAME0x00000200LFire for rename/move operations.

The NotifyRenameOrMoveFile event will fire anytime the OS renames or moves a file or directory.

FS_NE_GET_SECURITY0x00000400LFire for get security operations.

The NotifyGetFileSecurity event will fire anytime the OS queries the security attributes of a file or directory.

FS_NE_ENUMERATE_DIRECTORY0x00000800LFire for directory enumeration operations.

The NotifyEnumerateDirectory event will fire anytime the OS retrieves a directory entry during directory enumeration.

FS_NE_QUERY_FILE_INFO0x00001000LFire for QueryFileInformation operations.

The NotifyQueryFileInfo event will fire anytime the OS retrieves information about a file or directory.

FS_NE_GET_SIZES0x00002000LFire for get size operations.

The NotifyGetFileSizes event will fire anytime the OS retrieves a file's size information.

FS_NE_SET_SECURITY0x00004000LFire for set security operations.

The NotifySetFileSecurity event will fire anytime the OS changes the security attributes of a file or directory.

FS_NE_SET_ATTRIBUTES0x00008000LFire for file attribute update operations.

The NotifySetFileAttributes event will fire anytime the OS changes the attributes of a file or directory.

FS_NE_SET_SIZES0x00010000LFire for file resize operations.

The NotifySetFileSize event will fire anytime the OS resizes a file, and the NotifySetAllocationSize event will fire anytime the OS changes a file's allocation size.

FS_NE_CREATE_HARD_LINK0x00020000LFire for hard link creation operations.

The NotifyCreateHardLink event will fire anytime the OS creates a hard link.

FS_NE_FSCTL0x00040000LFire for FSCTL operations.

The NotifyFsctl event will fire anytime an IRP_MJ_FILE_SYSTEM_CONTROL operation occurs.

FS_NE_IOCTL0x00080000LFire for IOCTL operations.

The NotifyIoctl event will fire anytime an IRP_MJ_DEVICE_CONTROL operation occurs.

FS_NE_SET_FILE_INFO0x00100000LFire for SetFileInformation operations.

The NotifySetFileInfo event will fire anytime the OS changes information about a file or directory.

FS_NE_SET_EA0x00200000LFire for Set Extended Attributes operations.

The NotifySetEa event will fire anytime the OS sets extended attributes of a file.

FS_NE_QUERY_EA0x00400000LFire for Query Extended Attributes operations.

The NotifyQueryEa event will fire anytime the OS retrieves extended attributes of a file.

FS_NE_GET_REPARSE_POINT0x00800000LFire for Get Reparse Point operations.

The NotifyGetReparsePoint event will fire anytime the OS reads reparse point information of a file or directory.

FS_NE_SET_REPARSE_POINT0x01000000LFire for Set Reparse Point operations.

The NotifySetReparsePoint event will fire anytime the OS sets or updates reparse point information for a file or directory.

FS_NE_DELETE_REPARSE_POINT0x02000000LFire for Delete Reparse Point operations.

The NotifyDeleteReparsePoint event will fire anytime the OS deletes reparse point information from a file or directory.

FS_NE_ALL-1Fire for all filesystem operations.

Notification Events will fire for all filesystem operations that the component tracks.

Note: The methods and properties related to rule management are not intended to be used from multiple threads at once. Applications that wish to use said methods and properties from multiple threads (e.g., during the AfterFilterAttachToVolume and AfterFilterDetachFromVolume events) are responsible for employing proper thread synchronization techniques to ensure that manipulation and enumeration of the rule lists both occur in a thread-safe manner.

AddPassthroughRuleEx Method (CBFilter Component)

This method adds a passthrough rule with additional match qualifiers.

Syntax

public bool AddPassthroughRuleEx(string mask, string eaName, int accessFlags, long controlFlags, long notifyFlags, long minSize, long maxSize, long includedAttributes, long excludedAttributes);
Public Function AddPassthroughRuleEx(ByVal Mask As String, ByVal EaName As String, ByVal AccessFlags As Integer, ByVal ControlFlags As Long, ByVal NotifyFlags As Long, ByVal MinSize As Long, ByVal MaxSize As Long, ByVal IncludedAttributes As Long, ByVal ExcludedAttributes As Long) As Boolean

Remarks

This method adds a passthrough rule for the files and directories that match the specified Mask (which must be provided) and other qualifiers (which are optional). Each rule in a ruleset is uniquely identified by its mask; if a rule with the specified mask already exists, the new rule's parameters are merged into it.

If the rule is added successfully, this method returns true; otherwise, it returns false.

Passthrough rules exclude matching files and directories from being processed by other filter rules.

The Mask parameter must be a valid file mask according to the File Masks topic. Only the files and directories that match the specified mask will be covered by the rule.

The EaName parameter specifies the name of an extended attribute that a file or directory must have to qualify as a match; wildcards are not allowed. Pass an empty string if this parameter should not be used as a match qualifier.

The AccessFlags parameter specifies which access restrictions the component's system driver should lift from matching files and directories. The value passed for this parameter should be constructed by ORing together zero or more of the following flags:

ACCESS_NONE0x00No access restrictions.

ACCESS_READ_ONLY0x01Read-only access; writing and deleting are prohibited.

ACCESS_WRITE_ONLY0x02Write-only access; reading and deleting are prohibited.

ACCESS_DELETE_PROTECT0x04Deleting and renaming are prohibited.

ACCESS_EXECUTE_PROTECT0x08Execution is prohibited.

ACCESS_NO_CHANGE_DAC0x10Change of security attributes is prohibited.

ACCESS_NO_CHANGE_OWNER0x20Change of owner is prohibited.

ACCESS_RENAME_PROTECT0x40Renaming is prohibited.

ACCESS_DELETE_ONLY_PROTECT0x80Deleting is prohibited (renaming is not affected).

ACCESS_REMOTE_ACCESS_PROTECT0x100Access from other systems is prohibited.

ACCESS_DENY_ALL0x200All access is denied.

ACCESS_ALL_FLAGS-1Used to denote all currently set access restriction flags.

The ControlFlags parameter specifies which filesystem operations the component should not fire Control Events for. The value passed for this parameter should be constructed by ORing together zero or more of the following flags:

FS_CE_NONE0Don't fire for any filesystem operations.

Control Events will not fire for any filesystem operations.

FS_CE_BEFORE_CREATE0x000000000001LFire before file creation operations.

The BeforeCreateFile event will fire anytime the OS attempts to create a file or directory. In some cases, this event can cause the BeforeOpenFile event to fire; refer to the File Create/Open Events topic for more information.

FS_CE_AFTER_CREATE0x000000000002LFire after file creation operations.

The AfterCreateFile event will fire after a file or directory creation request has been processed, before the response is returned. In some cases, this event can cause the AfterOpenFile event to fire; refer to the File Create/Open Events topic for more information.

FS_CE_BEFORE_OPEN0x000000000004LFire before file open operations.

The BeforeOpenFile event will fire anytime the OS attempts to open a file or directory. In some cases, this event can cause the BeforeCreateFile event to fire; refer to the File Create/Open Events topic for more information.

FS_CE_AFTER_OPEN0x000000000008LFire after file open operations.

The AfterOpenFile event will fire after a file or directory open request has been processed, before the response is returned. In some cases, this event can cause the AfterCreateFile event to fire; refer to the File Create/Open Events topic for more information.

FS_CE_BEFORE_READ0x000000000010LFire before read operations.

The BeforeReadFile event will fire anytime the OS attempts to read data from a file.

FS_CE_AFTER_READ0x000000000020LFire after read operations.

The AfterReadFile event will fire after a read request has been processed, before the response is returned.

FS_CE_BEFORE_WRITE0x000000000040LFire before write operations.

The BeforeWriteFile event will fire anytime the OS attempts to write data to a file.

FS_CE_AFTER_WRITE0x000000000080LFire after write operations.

The AfterReadFile event will fire after a write request has been processed, before the response is returned.

FS_CE_BEFORE_LOCK_CONTROL0x000000000100LFire before lock and unlock operations.

The BeforeLock, BeforeUnlockAll, BeforeUnlockAllByKey, and BeforeUnlockSingle events will fire, as applicable, before the OS attempts to lock or unlock a range of bytes in a file.

FS_CE_AFTER_LOCK_CONTROL0x000000000200LFire before and after lock and unlock operations.

The AfterLock, AfterUnlockAll, AfterUnlockAllByKey, and AfterUnlockSingle, events will fire, as applicable, after a lock or unlock request has been processed, before the response is returned.

FS_CE_BEFORE_CLEANUP0x000000000400LFire before file handle cleanup operations.

The BeforeCleanupFile event will fire anytime a process closes a file or directory handle.

FS_CE_AFTER_CLEANUP0x000000000800LFire after file handle cleanup operations.

The AfterCleanupFile event will fire after a file handle cleanup request has been processed, before the response is returned.

FS_CE_BEFORE_CLOSE0x000000001000LFire before file close operations.

The BeforeCloseFile event will fire anytime the OS closes a file or directory. Also, the AfterCloseEnumeration event will fire anytime the OS closes a directory enumeration (which typically occurs immediately before the directory is closed).

FS_CE_AFTER_CLOSE0x000000002000LFire after file close operations.

The AfterCloseFile event will fire after a file/directory close request has been processed, before the response is returned.

FS_CE_BEFORE_CAN_DELETE0x000000004000LFire before 'can be deleted' operations.

The BeforeCanFileBeDeleted event will fire anytime the OS checks whether a file or directory can be deleted.

FS_CE_AFTER_CAN_DELETE0x000000008000LFire after 'can be deleted' operations.

The AfterCanFileBeDeleted event will fire after a can be deleted request has been processed, before the response is returned.

FS_CE_BEFORE_DELETE0x000000010000LFire before delete operations

The BeforeDeleteFile event will fire anytime the OS attempts to delete a file or directory.

FS_CE_AFTER_DELETE0x000000020000LFire after delete operations.

The AfterDeleteFile event will fire after a delete request has been processed, before the response is returned.

FS_CE_BEFORE_RENAME0x000000040000LFire before rename/move operations.

The BeforeRenameOrMoveFile event will fire anytime the OS attempts to rename or move a file or directory.

FS_CE_AFTER_RENAME0x000000080000LFire after rename/move operations.

The AfterRenameOrMoveFile event will fire after a rename or move request has been processed, before the response is returned.

FS_CE_BEFORE_GET_SECURITY0x000000100000LFire before get security operations.

The BeforeGetFileSecurity event will fire before the OS queries the security attributes of a file or directory.

FS_CE_AFTER_GET_SECURITY0x000000200000LFire after get security operations.

The AfterGetFileSecurity events will fire after a get security operation has been processed, before the response is returned.

FS_CE_BEFORE_ENUMERATE_DIRECTORY0x000000400000LFire before directory enumeration operations.

The BeforeEnumerateDirectory event will fire anytime the OS needs to read information about directory entries.

FS_CE_AFTER_ENUMERATE_DIRECTORY0x000000800000LFire after directory enumeration operations.

The AfterEnumerateDirectory event will fire after information about a directory entry has been retrieved during directory enumeration, before the response is returned.

FS_CE_BEFORE_QUERY_FILE_INFO0x000001000000LFire before 'query file information' operations.

The BeforeQueryFileInfo event will fire anytime the OS needs to retrieve information about a file or directory.

FS_CE_AFTER_QUERY_FILE_INFO0x000002000000LFire after 'query file information' operations.

The AfterQueryFileInfo event will fire after a file or directory information query request has been processed, before the response is returned.

FS_CE_AFTER_GET_SIZES0x000008000000LFire after get size operations.

The AfterGetFileSizes event will fire after a file's size information is retrieved, before the response is returned.

FS_CE_BEFORE_SET_SECURITY0x000010000000LFire before set security operations.

The BeforeSetFileSecurity event will fire anytime the OS needs to change the security attributes of a file or directory.

FS_CE_AFTER_SET_SECURITY0x000020000000LFire after set security operations.

The AfterSetFileSecurity event will fire after a security attribute change request has been processed, before the response is returned.

FS_CE_BEFORE_SET_ATTRIBUTES0x000040000000LFire before file attribute update operations.

The BeforeSetFileAttributes event will fire anytime the OS attempts to change the attributes of a file or directory.

FS_CE_AFTER_SET_ATTRIBUTES0x000080000000LFire after file attribute update operations.

The AfterSetFileAttributes event will fire after a file attribute change request has been processed, before the response is returned.

FS_CE_BEFORE_SET_SIZES0x000100000000LFire before file resize operations.

The BeforeSetFileSize event will fire anytime the OS attempts to resize a file, and the BeforeSetAllocationSize event will fire anytime the OS attempts to change a file's allocation size.

FS_CE_AFTER_SET_SIZES0x000200000000LFire after file resize operations.

The AfterSetFileSize event will fire after a file resize request has been processed, and the AfterSetAllocationSize event will fire after a file allocation size change request has been processed, before the response is returned.

FS_CE_BEFORE_CREATE_HARD_LINK0x000400000000LFire before hard link creation operations.

The BeforeCreateHardLink event will fire anytime the OS attempts to create a hard link.

FS_CE_AFTER_CREATE_HARD_LINK0x000800000000LFire after hard link creation operations.

The AfterCreateHardLink events will fire after a hard link creation request has been processed, before the response is returned.

FS_CE_BEFORE_FSCTL0x001000000000LFire before FSCTL operations.

The BeforeFsctl event will fire anytime an IRP_MJ_FILE_SYSTEM_CONTROL request occurs.

FS_CE_AFTER_FSCTL0x002000000000LFire after FSCTL operations.

The AfterFsctl event will fire after an IRP_MJ_FILE_SYSTEM_CONTROL request has been processed, before the response is returned.

FS_CE_BEFORE_IOCTL0x004000000000LFire before IOCTL operations.

The BeforeIoctl event will fire anytime an IRP_MJ_DEVICE_CONTROL request occurs.

FS_CE_AFTER_IOCTL0x008000000000LFire after IOCTL operations.

The AfterIoctl event will fire after an IRP_MJ_DEVICE_CONTROL request has been processed, before the response is returned.

FS_CE_BEFORE_SET_FILE_INFO0x010000000000LFire before 'set file information' operations.

The BeforeSetFileInfo event will fire anytime the OS needs to change information about a file or directory.

FS_CE_AFTER_SET_FILE_INFO0x020000000000LFire after 'set file information' operations.

The AfterSetFileInfo event will fire after a file or directory information change request has been processed, before the response is returned.

FS_CE_BEFORE_SET_EA0x040000000000LFire before Set Extended Attributes operations.

The BeforeSetEa event will fire anytime the OS needs to set extended attributes of a file.

FS_CE_AFTER_SET_EA0x080000000000LFire after Set Extended Attributes operations.

The AfterSetEa event will fire after the OS request to set extended attributes of a file has been processed, before the response is returned.

FS_CE_BEFORE_QUERY_EA0x100000000000LFire before Query Extended Attributes operations.

The BeforeQueryEa event will fire anytime the OS needs to retrieve extended attributes of a file.

FS_CE_AFTER_QUERY_EA0x200000000000LFire after Query Extended Attributes operations.

The AfterQueryEa event will fire after the OS request to retrieve extended attributes of a file has been processed, before the response is returned.

FS_CE_BEFORE_GET_REPARSE_POINT0x400000000000LFire before Get Reparse Point operations.

The BeforeGetReparsePoint event will fire anytime the OS needs to read a reparse point of a file or directory.

FS_CE_AFTER_GET_REPARSE_POINT0x800000000000LFire after Get Reparse Point operations.

The AfterGetReparsePoint event will fire after the OS request to read a reparse point of a file or directory has been processed, before the response is returned.

FS_CE_BEFORE_SET_REPARSE_POINT0x1000000000000LFire before Set Reparse Point operations.

The BeforeSetReparsePoint event will fire anytime the OS needs to set or update a reparse point for a file or directory.

FS_CE_AFTER_SET_REPARSE_POINT0x2000000000000LFire after Set Reparse Point operations.

The AfterSetReparsePoint event will fire after the OS request to set or update a reparse point for a file or directory has been processed, before the response is returned.

FS_CE_BEFORE_DELETE_REPARSE_POINT0x4000000000000LFire before Delete Reparse Point operations.

The BeforeDeleteReparsePoint event will fire anytime the OS needs to remove reparse point information from a file or directory.

FS_CE_AFTER_DELETE_REPARSE_POINT0x8000000000000LFire after Delete Reparse Point operations.

The AfterDeleteReparsePoint event will fire after the OS request to remove reparse point information from a file or directory has been processed, before the response is returned.

FS_CE_REPARSE_FILENAME0x40000000000000LFire before various operations for the purpose of file redirection.

The ReparseFileName event will fire before any operation that includes a file or directory name, giving the application a chance to redirect it. This event is typically used when an application requires more advanced redirection logic than Reparse Rules can provide; please refer to that topic for more information.

FS_CE_REPARSE_TAG0x80000000000000LFire for reparse operations.

The ReparseWithTag event will fire anytime a file/directory open operation returns a STATUS_REPARSE result, allowing the application to handle the reparse point. Please refer to Microsoft's Reparse Points article for more information.

FS_CE_ALL-1Fire for all filesystem operations.

Control Events will fire for all filesystem operations that the component tracks.

The NotifyFlags parameter specifies which filesystem operations the component should not fire Notification Events for. The value passed for this parameter should be constructed by ORing together zero or more of the following flags:

FS_NE_NONE0Don't fire for any filesystem operations.

Notification Events will not fire for any filesystem operations.

FS_NE_CREATE0x00000001LFire for file creation operations.

The NotifyCreateFile event will fire anytime the OS creates a file or directory. In some cases, this event can cause the NotifyOpenFile event to fire; refer to the File Create/Open Events topic for more information.

FS_NE_OPEN0x00000002LFire for file open operations.

The NotifyOpenFile event will fire anytime the OS opens a file or directory. In some cases, this event can cause the NotifyCreateFile event to fire; refer to the File Create/Open Events topic for more information.

FS_NE_READ0x00000004LFire for read operations.

The NotifyReadFile event will fire anytime the OS reads data from a file.

FS_NE_WRITE0x00000008LFire for write operations.

The NotifyWriteFile event will fire anytime the OS writes data to a file.

FS_NE_LOCK_CONTROL0x00000010LFire for lock and unlock operations.

The NotifyLock, NotifyUnlockAll, NotifyUnlockAllByKey, and NotifyUnlockSingle events will fire, as applicable, anytime the OS locks or unlocks a range of bytes in a file.

FS_NE_CLEANUP0x00000020LFire for file handle cleanup operations.

The NotifyCleanupFile event will fire anytime a process closes a file or directory handle.

FS_NE_CLOSE0x00000040LFire for file close operations.

The NotifyCloseFile event will fire anytime the OS closes a file or directory.

FS_NE_CAN_DELETE0x00000080LFire for 'can be deleted' operations.

The NotifyCanFileBeDeleted event will fire anytime the OS checks whether or not a file or directory can be deleted.

FS_NE_DELETE0x00000100LFire for delete operations.

The NotifyDeleteFile event will fire anytime the OS deletes a file or directory.

FS_NE_RENAME0x00000200LFire for rename/move operations.

The NotifyRenameOrMoveFile event will fire anytime the OS renames or moves a file or directory.

FS_NE_GET_SECURITY0x00000400LFire for get security operations.

The NotifyGetFileSecurity event will fire anytime the OS queries the security attributes of a file or directory.

FS_NE_ENUMERATE_DIRECTORY0x00000800LFire for directory enumeration operations.

The NotifyEnumerateDirectory event will fire anytime the OS retrieves a directory entry during directory enumeration.

FS_NE_QUERY_FILE_INFO0x00001000LFire for QueryFileInformation operations.

The NotifyQueryFileInfo event will fire anytime the OS retrieves information about a file or directory.

FS_NE_GET_SIZES0x00002000LFire for get size operations.

The NotifyGetFileSizes event will fire anytime the OS retrieves a file's size information.

FS_NE_SET_SECURITY0x00004000LFire for set security operations.

The NotifySetFileSecurity event will fire anytime the OS changes the security attributes of a file or directory.

FS_NE_SET_ATTRIBUTES0x00008000LFire for file attribute update operations.

The NotifySetFileAttributes event will fire anytime the OS changes the attributes of a file or directory.

FS_NE_SET_SIZES0x00010000LFire for file resize operations.

The NotifySetFileSize event will fire anytime the OS resizes a file, and the NotifySetAllocationSize event will fire anytime the OS changes a file's allocation size.

FS_NE_CREATE_HARD_LINK0x00020000LFire for hard link creation operations.

The NotifyCreateHardLink event will fire anytime the OS creates a hard link.

FS_NE_FSCTL0x00040000LFire for FSCTL operations.

The NotifyFsctl event will fire anytime an IRP_MJ_FILE_SYSTEM_CONTROL operation occurs.

FS_NE_IOCTL0x00080000LFire for IOCTL operations.

The NotifyIoctl event will fire anytime an IRP_MJ_DEVICE_CONTROL operation occurs.

FS_NE_SET_FILE_INFO0x00100000LFire for SetFileInformation operations.

The NotifySetFileInfo event will fire anytime the OS changes information about a file or directory.

FS_NE_SET_EA0x00200000LFire for Set Extended Attributes operations.

The NotifySetEa event will fire anytime the OS sets extended attributes of a file.

FS_NE_QUERY_EA0x00400000LFire for Query Extended Attributes operations.

The NotifyQueryEa event will fire anytime the OS retrieves extended attributes of a file.

FS_NE_GET_REPARSE_POINT0x00800000LFire for Get Reparse Point operations.

The NotifyGetReparsePoint event will fire anytime the OS reads reparse point information of a file or directory.

FS_NE_SET_REPARSE_POINT0x01000000LFire for Set Reparse Point operations.

The NotifySetReparsePoint event will fire anytime the OS sets or updates reparse point information for a file or directory.

FS_NE_DELETE_REPARSE_POINT0x02000000LFire for Delete Reparse Point operations.

The NotifyDeleteReparsePoint event will fire anytime the OS deletes reparse point information from a file or directory.

FS_NE_ALL-1Fire for all filesystem operations.

Notification Events will fire for all filesystem operations that the component tracks.

The MinSize and MaxSize parameters specify the minimum and maximum size, in bytes, that a file can be to qualify as a match. Pass -1 for either parameter if it should not be used as a match qualifier.

The IncludedAttributes and ExcludedAttributes parameters specify which file attributes a file or directory must have or not have to qualify as a match. Pass 0 for either parameter if it should not be used as a match qualifier.

Note: The methods and properties related to rule management are not intended to be used from multiple threads at once. Applications that wish to use said methods and properties from multiple threads (e.g., during the AfterFilterAttachToVolume and AfterFilterDetachFromVolume events) are responsible for employing proper thread synchronization techniques to ensure that manipulation and enumeration of the rule lists both occur in a thread-safe manner.

AddReparseRule Method (CBFilter Component)

This method adds a reparse rule.

Syntax

public bool AddReparseRule(string mask, string reparseMask, string productGUID, int flags);
Public Function AddReparseRule(ByVal Mask As String, ByVal ReparseMask As String, ByVal ProductGUID As String, ByVal Flags As Integer) As Boolean

Remarks

This method adds a reparse rule for the files and directories that match the specified Mask. Each rule in a ruleset is uniquely identified by its mask; if a rule with the specified mask already exists, the new rule replaces it.

If the rule is added successfully, this method returns true; otherwise, it returns false.

Reparse rules are used to redirect access from a file or directory covered by Mask to another location in the filesystem, specified by ReparseMask.

The Mask and ReparseMask parameters must be valid file masks according to the File Masks topic. Only the files and directories that match Mask will be covered by the rule (i.e., redirected to the path specified by ReparseMask). For example, passing *.txt for Mask and *_1.txt for ReparseMask would cause, for example, test.txt to be redirected to test_1.txt.

More generally, for each wildcard (* or ?) present in Mask, there must be a corresponding wildcard (of the same type) in ReparseMask; and the wildcards in ReparseMask must appear in the same order as they do in Mask. For example, if Mask is 20??_Budget.*, then 20??_Budget_Report.* would be a legal value for ReparseMask; but 20??_Budget_Report.xls would not be, nor would 20*_Budget_Report.*.

The ProductGUID parameter identifies the application that the rule should be associated with in the registry. In most cases, the value passed for this parameter should be the same one that was used to call the Initialize method.

The Flags parameter specifies how, exactly, the redirection should be performed. Possible values are as follows:

FS_REPARSE_CHANGE_PATH0Perform redirection by modifying the path directly using the CBFilter system driver.

FS_REPARSE_USE_REPARSE_POINT1Perform redirection by having the CBFilter system driver emulate real reparse point behavior.

This option will cause the driver to report that a file or directory's parent directory is a reparse point of the SYMLINK variety. Redirection performed in this manner is more consistent with Windows' behavior; however, some software may fail to correctly handle paths that cross such symbolic links.

Note: The methods and properties related to rule management are not intended to be used from multiple threads at once. Applications that wish to use said methods and properties from multiple threads (e.g., during the AfterFilterAttachToVolume and AfterFilterDetachFromVolume events) are responsible for employing proper thread synchronization techniques to ensure that manipulation and enumeration of the rule lists both occur in a thread-safe manner.

CloseDefaultRulesSnapshot Method (CBFilter Component)

This method closes the previously created default rules snapshot.

Syntax

public void CloseDefaultRulesSnapshot();
Public Sub CloseDefaultRulesSnapshot()

Remarks

This method closes the default rules snapshot previously created by CreateDefaultRulesSnapshot, releasing the memory associated with it. Please refer to that method's documentation for more information.

Note: This method cannot be called within events.

The methods and properties related to rule management are not intended to be used from multiple threads at once. Applications that wish to use said methods and properties from multiple threads (e.g., during the AfterFilterAttachToVolume and AfterFilterDetachFromVolume events) are responsible for employing proper thread synchronization techniques to ensure that manipulation and enumeration of the rule lists both occur in a thread-safe manner.

CloseReparseRulesSnapshot Method (CBFilter Component)

This method closes the previously created reparse rules snapshot.

Syntax

public void CloseReparseRulesSnapshot();
Public Sub CloseReparseRulesSnapshot()

Remarks

This method closes the reparse rules snapshot previously created by CreateReparseRulesSnapshot, releasing the memory associated with it. Please refer to that method's documentation for more information.

Note: This method cannot be called within events.

The methods and properties related to rule management are not intended to be used from multiple threads at once. Applications that wish to use said methods and properties from multiple threads (e.g., during the AfterFilterAttachToVolume and AfterFilterDetachFromVolume events) are responsible for employing proper thread synchronization techniques to ensure that manipulation and enumeration of the rule lists both occur in a thread-safe manner.

Config Method (CBFilter Component)

Sets or retrieves a configuration setting.

Syntax

public string Config(string configurationString);
Public Function Config(ByVal ConfigurationString As String) As String

Remarks

Config is a generic method available in every component. It is used to set and retrieve configuration settings for the component.

These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the component, access to these internal properties is provided through the Config method.

To set a configuration setting named PROPERTY, you must call Config("PROPERTY=VALUE"), where VALUE is the value of the setting expressed as a string. For boolean values, use the strings "True", "False", "0", "1", "Yes", or "No" (case does not matter).

To read (query) the value of a configuration setting, you must call Config("PROPERTY"). The value will be returned as a string.

CreateDefaultRulesSnapshot Method (CBFilter Component)

This method creates a snapshot of information about the default rules that have been added.

Syntax

public void CreateDefaultRulesSnapshot(string productGUID);
Public Sub CreateDefaultRulesSnapshot(ByVal ProductGUID As String)

Remarks

This method creates a snapshot of information about all default rules that have been added by the application identified by ProductGUID. This information is then used to populate the DefaultRules collection property.

When the application is finished working with the default rules snapshot, it must close it by calling the CloseDefaultRulesSnapshot method to release the associated memory. If this method is called again before an existing snapshot is closed, the component will attempt to close it before creating a new one.

Note: This method cannot be called within events.

The methods and properties related to rule management are not intended to be used from multiple threads at once. Applications that wish to use said methods and properties from multiple threads (e.g., during the AfterFilterAttachToVolume and AfterFilterDetachFromVolume events) are responsible for employing proper thread synchronization techniques to ensure that manipulation and enumeration of the rule lists both occur in a thread-safe manner.

CreateFileDirect Method (CBFilter Component)

This method creates or opens a file or directory by passing the request directly to the filesystem.

Syntax

public long CreateFileDirect(string fileName, bool synchronize, int desiredAccess, int shareMode, int creationDisposition, int flagsAndAttributes, bool closeImmediately);
Public Function CreateFileDirect(ByVal FileName As String, ByVal Synchronize As Boolean, ByVal DesiredAccess As Integer, ByVal ShareMode As Integer, ByVal CreationDisposition As Integer, ByVal FlagsAndAttributes As Integer, ByVal CloseImmediately As Boolean) As Long

Remarks

This method should be used instead of the Windows API's CreateFile function to create or open a file or directory when an application needs to access it without sending requests through the filesystem filter driver stack.

The parameters of this method correspond to the parameters of the CreateFile function.

If the file or directory is created or opened successfully, this method returns a file handle for it; otherwise, it returns INVALID_HANDLE_VALUE. The returned handle, if valid, must be closed using the Windows API's CloseHandle function when the application is finished with it.

If CloseImmediately is true, this method will create or open the specified file or directory and then immediately close the resulting handle. In this case, the handle will still be returned to indicate the success of the operation, but it will not be usable in any file operations.

Because all requests against the returned file handle are routed directly to the filesystem (bypassing all filter drivers, including the component's), applications can use it to call the Windows File API functions (ReadFile, WriteFile) within filesystem-related events without causing a system deadlock. However, pay special attention to the Synchronize parameter's documentation, which is given below.

The returned handle can be used with some of the Windows API functions that accept a file handle as a parameter. Support may vary depending on the internal implementation of each function. The following Windows API functions have been tested and proven to work:

Other functions may work as well but have not been tested.

Note: When calling the GetFileInformationByHandleEx function, only the following information classes are currently supported:

  • FileAttributeTagInfo
  • FileBasicInfo
  • FileStandardInfo
  • FileStreamInfo
  • FileIdInfo
Support for other information classes depends on the class and OS capabilities.

The FileName, DesiredAccess, CreationDisposition, and FlagsAndAttributes parameters correspond to the lpFileName, dwDesiredAccess, dwCreationDisposition, and dwFlagsAndAttributes parameters of the Windows API's CreateFile function (respectively). Please refer to Microsoft's documentation for more information about how to set these parameters appropriately.

The ShareMode parameter should be set by ORing together zero or more of the following flags:

FILESYS_SHARE_NONE0x00000000Prevents any process from opening a file or device if it requests delete, read, or write access.

FILESYS_SHARE_READ0x00000001Enables subsequent open operations on a file or device to request read access.

Enables subsequent open operations to request read access; otherwise, no process can open the file or device if it requests read access. If this flag is not specified, but the file or device has been opened for read access, the function fails.

FILESYS_SHARE_WRITE0x00000002Enables subsequent open operations on a file or device to request write access.

Enables subsequent open operations to request write access; otherwise, no process can open the file or device if it requests write access. If this flag is not specified, but the file or device has been opened for write access or has a file mapping with write access, the function fails.

FILESYS_SHARE_DELETE0x00000004Enables subsequent open operations on a file or device to request delete access.

Enables subsequent open operations to request delete access; otherwise, no process can open the file or device if it requests delete access. If this flag is not specified, but the file or device has been opened for delete access, the function fails.

Note: Delete access allows both delete and rename operations.

CBFILTER_IGNORE_SHARE_ACCESS_CHECK0x10000000Specifies that the driver should pass IO_IGNORE_SHARE_ACCESS_CHECK flag to the system functions.

Use this flag to bypass sharing checks performed by the I/O manager when opening local files.

Note: The filesystem still may perform these checks. Also, the internal structures are not updated with the share mode values, passed in this call. This means that subsequent file open operations will not know about the previous share mode and may succeed where they would have to fail.

The Synchronize parameter specifies whether this method and operations with the resulting handle should be synchronized with the thread that originated the underlying filesystem request associated with the current event (i.e., the event that this method was called from).

The parameter is applicable only when a caller uses it to open the file, for which the event was fired. Also, the parameter should not be set to True when this method is called from the AfterCloseFile event; when the event is fired, no file is open to synchronize operations with.

If Synchronize is true, this method and all operations with the resulting handle will be execute in the context of the external thread that originated the underlying filesystem request associated with the current event (which is important for on-the-fly file data modification like encryption), and the following restrictions will apply:

  • The method may be called from any event handlers with the exception of AfterCloseFile and CleanupContext. Note: To be able to call the method from the BeforeCreateFile and BeforeOpenFile event handlers, set the AllowFileAccessInBeforeOpen configuration setting to true.
  • The method should be called only for the file or directory that the event fired for.
  • A file will be opened without buffering, which means that applications must comply with all restrictions imposed by the FILE_FLAG_NO_BUFFERING flag when reading and writing file data. Please refer to Microsoft's File Buffering article for more information.
There also exists a limitation in how the method works in the following scenario: if the method is called from a BeforeCreateFile or BeforeOpenFile event handler and the file doesn't exist and the method is used to create this file, then writing to this file from the same event handler will not work. The reason is that the file didn't exist at the moment when the event was fired, so the driver cannot synchronize the operations properly. The solution is to move the file writing step to the AfterCreateFile and AfterOpenFile event handler respectively. There, an application may use the handle obtained in BeforeCreateFile or BeforeOpenFile and write data to that file.

If Synchronize is false, this method and operations with the resulting handle are executed in the context of the thread in which the corresponding call is made, and the restrictions described above do not apply. This provides applications with greater flexibility because the returned file handle can be used in any event (as long as its handler complies with the general restrictions described by the Avoiding Deadlocks and Recursive Calls topics).

In both cases, the component must be active - that is, it must be started using a call to the StartFilter method.

CreateFileDirectAsStream Method (CBFilter Component)

This method creates or opens a file by passing the request directly to the filesystem.

Syntax

public CBFSFilterStream CreateFileDirectAsStream(string fileName, bool synchronize, int desiredAccess, int shareMode, int creationDisposition, int flagsAndAttributes, ref long handle);
Public Function CreateFileDirectAsStream(ByVal FileName As String, ByVal Synchronize As Boolean, ByVal DesiredAccess As Integer, ByVal ShareMode As Integer, ByVal CreationDisposition As Integer, ByVal FlagsAndAttributes As Integer, ByRef Handle As Long) As CBFSFilterStream

Remarks

This method should be used instead of the Windows API's CreateFile function to create or open a file when an application needs to access it without sending requests through the filesystem filter driver stack.

The parameters of this method correspond to the parameters of the CreateFile function.

If the file is created or opened successfully, this method returns a stream object that provides access to its data; otherwise, it returns null. Upon success, the Handle parameter is populated with the handle value, which can be used to call SetFileSizeDirect or SetFileInformationDirect if needed.

Because all requests against the file are routed directly to the filesystem (bypassing all filter drivers, including the component's), applications can use the returned stream within filesystem-related events without causing a system deadlock. However, pay special attention to the Synchronize parameter's documentation, which is given below.

The FileName, DesiredAccess, CreationDisposition, and FlagsAndAttributes parameters correspond to the lpFileName, dwDesiredAccess, dwCreationDisposition, and dwFlagsAndAttributes parameters of the Windows API's CreateFile function (respectively). Please refer to Microsoft's documentation for more information about how to set these parameters appropriately.

The ShareMode parameter should be set by ORing together zero or more of the following flags:

FILESYS_SHARE_NONE0x00000000Prevents any process from opening a file or device if it requests delete, read, or write access.

FILESYS_SHARE_READ0x00000001Enables subsequent open operations on a file or device to request read access.

Enables subsequent open operations to request read access; otherwise, no process can open the file or device if it requests read access. If this flag is not specified, but the file or device has been opened for read access, the function fails.

FILESYS_SHARE_WRITE0x00000002Enables subsequent open operations on a file or device to request write access.

Enables subsequent open operations to request write access; otherwise, no process can open the file or device if it requests write access. If this flag is not specified, but the file or device has been opened for write access or has a file mapping with write access, the function fails.

FILESYS_SHARE_DELETE0x00000004Enables subsequent open operations on a file or device to request delete access.

Enables subsequent open operations to request delete access; otherwise, no process can open the file or device if it requests delete access. If this flag is not specified, but the file or device has been opened for delete access, the function fails.

Note: Delete access allows both delete and rename operations.

CBFILTER_IGNORE_SHARE_ACCESS_CHECK0x10000000Specifies that the driver should pass IO_IGNORE_SHARE_ACCESS_CHECK flag to the system functions.

Use this flag to bypass sharing checks performed by the I/O manager when opening local files.

Note: The filesystem still may perform these checks. Also, the internal structures are not updated with the share mode values, passed in this call. This means that subsequent file open operations will not know about the previous share mode and may succeed where they would have to fail.

The Synchronize parameter specifies whether this method and operations with the resulting handle should be synchronized with the thread that originated the underlying filesystem request associated with the current event (i.e., the event that this method was called from).

The parameter is applicable only when a caller uses it to open the file, for which the event was fired. Also, the parameter should not be set to True when this method is called from the AfterCloseFile event; when the event is fired, no file is open to synchronize operations with.

If Synchronize is true, this method and all operations with the resulting handle will be execute in the context of the external thread that originated the underlying filesystem request associated with the current event (which is important for on-the-fly file data modification like encryption), and the following restrictions will apply:

  • The method may be called from any event handlers with the exception of AfterCloseFile and CleanupContext. Note: To be able to call the method from the BeforeCreateFile and BeforeOpenFile event handlers, set the AllowFileAccessInBeforeOpen configuration setting to true.
  • The method should be called only for the file or directory that the event fired for.
  • A file will be opened without buffering, which means that applications must comply with all restrictions imposed by the FILE_FLAG_NO_BUFFERING flag when reading and writing file data. Please refer to Microsoft's File Buffering article for more information.
There also exists a limitation in how the method works in the following scenario: if the method is called from a BeforeCreateFile or BeforeOpenFile event handler and the file doesn't exist and the method is used to create this file, then writing to this file from the same event handler will not work. The reason is that the file didn't exist at the moment when the event was fired, so the driver cannot synchronize the operations properly. The solution is to move the file writing step to the AfterCreateFile and AfterOpenFile event handler respectively. There, an application may use the handle obtained in BeforeCreateFile or BeforeOpenFile and write data to that file.

If Synchronize is false, this method and operations with the resulting handle are executed in the context of the thread in which the corresponding call is made, and the restrictions described above do not apply. This provides applications with greater flexibility because the returned file handle can be used in any event (as long as its handler complies with the general restrictions described by the Avoiding Deadlocks and Recursive Calls topics).

In both cases, the component must be active - that is, it must be started using a call to the StartFilter method.

CreateReparseRulesSnapshot Method (CBFilter Component)

This method creates a snapshot of information about the reparse rules that have been added.

Syntax

public void CreateReparseRulesSnapshot(string productGUID);
Public Sub CreateReparseRulesSnapshot(ByVal ProductGUID As String)

Remarks

This method creates a snapshot of information about all reparse rules that have been added by the application identified by ProductGUID. This information is then used to populate the ReparseRules collection property.

When the application is finished working with the reparse rules snapshot, it must close it by calling the CloseReparseRulesSnapshot method to release the associated memory. If this method is called again before an existing snapshot is closed, the component will attempt to close it before creating a new one.

Note: This method cannot be called within events.

The methods and properties related to rule management are not intended to be used from multiple threads at once. Applications that wish to use said methods and properties from multiple threads (e.g., during the AfterFilterAttachToVolume and AfterFilterDetachFromVolume events) are responsible for employing proper thread synchronization techniques to ensure that manipulation and enumeration of the rule lists both occur in a thread-safe manner.

CreateVirtualFile Method (CBFilter Component)

This method is under construction.

Syntax

public long CreateVirtualFile(string fileName, int desiredAccess, int shareMode, int creationDisposition, int flagsAndAttributes);
Public Function CreateVirtualFile(ByVal FileName As String, ByVal DesiredAccess As Integer, ByVal ShareMode As Integer, ByVal CreationDisposition As Integer, ByVal FlagsAndAttributes As Integer) As Long

Remarks

This method is under construction.

DeleteAllFilterRules Method (CBFilter Component)

This method deletes all standard filter rules and access rules.

Syntax

public bool DeleteAllFilterRules();
Public Function DeleteAllFilterRules() As Boolean

Remarks

This method deletes all standard filter rules and access rules that are currently present.

If the rules are deleted successfully, this method returns true; otherwise, it returns false.

To delete standard filter rules or access rules individually, use the DeleteFilterRule method instead.

Note: The methods and properties related to rule management are not intended to be used from multiple threads at once. Applications that wish to use said methods and properties from multiple threads (e.g., during the AfterFilterAttachToVolume and AfterFilterDetachFromVolume events) are responsible for employing proper thread synchronization techniques to ensure that manipulation and enumeration of the rule lists both occur in a thread-safe manner.

DeleteAllPassthroughRules Method (CBFilter Component)

This method deletes all passthrough rules.

Syntax

public bool DeleteAllPassthroughRules();
Public Function DeleteAllPassthroughRules() As Boolean

Remarks

This method deletes all passthrough rules that are currently present.

If the rules are deleted successfully, this method returns true; otherwise, it returns false.

To delete passthrough rules individually, use the DeletePassthroughRule method instead.

Note: The methods and properties related to rule management are not intended to be used from multiple threads at once. Applications that wish to use said methods and properties from multiple threads (e.g., during the AfterFilterAttachToVolume and AfterFilterDetachFromVolume events) are responsible for employing proper thread synchronization techniques to ensure that manipulation and enumeration of the rule lists both occur in a thread-safe manner.

DeleteAllReparseRules Method (CBFilter Component)

This method deletes all reparse rules.

Syntax

public bool DeleteAllReparseRules(string productGUID);
Public Function DeleteAllReparseRules(ByVal ProductGUID As String) As Boolean

Remarks

This method deletes all reparse rules associated with the application identified by ProductGUID.

If the rules are deleted successfully, this method returns true; otherwise, it returns false.

In most cases, the value passed for the ProductGUID parameter should be the same one that was used to call the Initialize method. Please refer to the AddReparseRule method's documentation for more information.

To delete reparse rules individually, use the DeleteReparseRule method instead.

Note: The methods and properties related to rule management are not intended to be used from multiple threads at once. Applications that wish to use said methods and properties from multiple threads (e.g., during the AfterFilterAttachToVolume and AfterFilterDetachFromVolume events) are responsible for employing proper thread synchronization techniques to ensure that manipulation and enumeration of the rule lists both occur in a thread-safe manner.

DeleteDefaultRule Method (CBFilter Component)

This method deletes a particular default rule.

Syntax

public bool DeleteDefaultRule(string mask, int accessFlags, string productGUID);
Public Function DeleteDefaultRule(ByVal Mask As String, ByVal AccessFlags As Integer, ByVal ProductGUID As String) As Boolean

Remarks

This method deletes the specified AccessFlags from the default rule identified by Mask and associated with the application identified by ProductGUID. If AccessFlags includes all flags currently present in the rule, then the entire rule is deleted; otherwise, the flags specified by AccessFlags are simply removed from the rule.

If the flags or this rule are deleted successfully, this method returns true; otherwise, it returns false.

The Mask parameter must be the file mask of an existing rule. If a rule with the specified mask cannot be found, this method will fail.

The AccessFlags parameter specifies which access restrictions should be removed from the rule. The value passed for this parameter should be constructed by ORing together zero or more of the following flags:

ACCESS_NONE0x00No access restrictions.

ACCESS_READ_ONLY0x01Read-only access; writing and deleting are prohibited.

ACCESS_WRITE_ONLY0x02Write-only access; reading and deleting are prohibited.

ACCESS_DELETE_PROTECT0x04Deleting and renaming are prohibited.

ACCESS_EXECUTE_PROTECT0x08Execution is prohibited.

ACCESS_NO_CHANGE_DAC0x10Change of security attributes is prohibited.

ACCESS_NO_CHANGE_OWNER0x20Change of owner is prohibited.

ACCESS_RENAME_PROTECT0x40Renaming is prohibited.

ACCESS_DELETE_ONLY_PROTECT0x80Deleting is prohibited (renaming is not affected).

ACCESS_REMOTE_ACCESS_PROTECT0x100Access from other systems is prohibited.

ACCESS_DENY_ALL0x200All access is denied.

ACCESS_ALL_FLAGS-1Used to denote all currently set access restriction flags.

In most cases, the value passed for the ProductGUID parameter should be the same one that was used to call the Initialize method. Please refer to the AddDefaultRule method's documentation for more information.

This method requires administrative rights to execute successfully. If the user account of the process that calls this method doesn't have such rights, the call will fail with an ERROR_PRIVILEGE_NOT_HELD (0x0522) error. Please refer to the Default Rules topic for more information.

Note: The methods and properties related to rule management are not intended to be used from multiple threads at once. Applications that wish to use said methods and properties from multiple threads (e.g., during the AfterFilterAttachToVolume and AfterFilterDetachFromVolume events) are responsible for employing proper thread synchronization techniques to ensure that manipulation and enumeration of the rule lists both occur in a thread-safe manner.

DeleteFilterRule Method (CBFilter Component)

This method deletes a particular standard filter rule or access rule.

Syntax

public bool DeleteFilterRule(string mask, int accessFlags, long controlFlags, long notifyFlags);
Public Function DeleteFilterRule(ByVal Mask As String, ByVal AccessFlags As Integer, ByVal ControlFlags As Long, ByVal NotifyFlags As Long) As Boolean

Remarks

This method deletes the specified AccessFlags, ControlFlags, and/or NotifyFlags from the standard filter rule and/or access rule identified by Mask. If the aforementioned parameters include all flags currently present in the rule, then the entire rule is deleted; otherwise, the specified flags are simply removed from the rule.

If the flags or this rule are deleted successfully, this method returns true; otherwise, it returns false.

The Mask parameter must be the file mask of an existing rule. If a rule with the specified mask cannot be found, this method will fail.

The AccessFlags parameter specifies which access restrictions should be removed from the rule. The value passed for this parameter should be constructed by ORing together zero or more of the following flags:

ACCESS_NONE0x00No access restrictions.

ACCESS_READ_ONLY0x01Read-only access; writing and deleting are prohibited.

ACCESS_WRITE_ONLY0x02Write-only access; reading and deleting are prohibited.

ACCESS_DELETE_PROTECT0x04Deleting and renaming are prohibited.

ACCESS_EXECUTE_PROTECT0x08Execution is prohibited.

ACCESS_NO_CHANGE_DAC0x10Change of security attributes is prohibited.

ACCESS_NO_CHANGE_OWNER0x20Change of owner is prohibited.

ACCESS_RENAME_PROTECT0x40Renaming is prohibited.

ACCESS_DELETE_ONLY_PROTECT0x80Deleting is prohibited (renaming is not affected).

ACCESS_REMOTE_ACCESS_PROTECT0x100Access from other systems is prohibited.

ACCESS_DENY_ALL0x200All access is denied.

ACCESS_ALL_FLAGS-1Used to denote all currently set access restriction flags.

The ControlFlags parameter specifies which Control Event flags should be removed from the rule. The value passed for this parameter should be constructed by ORing together zero or more of the following flags:

FS_CE_NONE0Don't fire for any filesystem operations.

Control Events will not fire for any filesystem operations.

FS_CE_BEFORE_CREATE0x000000000001LFire before file creation operations.

The BeforeCreateFile event will fire anytime the OS attempts to create a file or directory. In some cases, this event can cause the BeforeOpenFile event to fire; refer to the File Create/Open Events topic for more information.

FS_CE_AFTER_CREATE0x000000000002LFire after file creation operations.

The AfterCreateFile event will fire after a file or directory creation request has been processed, before the response is returned. In some cases, this event can cause the AfterOpenFile event to fire; refer to the File Create/Open Events topic for more information.

FS_CE_BEFORE_OPEN0x000000000004LFire before file open operations.

The BeforeOpenFile event will fire anytime the OS attempts to open a file or directory. In some cases, this event can cause the BeforeCreateFile event to fire; refer to the File Create/Open Events topic for more information.

FS_CE_AFTER_OPEN0x000000000008LFire after file open operations.

The AfterOpenFile event will fire after a file or directory open request has been processed, before the response is returned. In some cases, this event can cause the AfterCreateFile event to fire; refer to the File Create/Open Events topic for more information.

FS_CE_BEFORE_READ0x000000000010LFire before read operations.

The BeforeReadFile event will fire anytime the OS attempts to read data from a file.

FS_CE_AFTER_READ0x000000000020LFire after read operations.

The AfterReadFile event will fire after a read request has been processed, before the response is returned.

FS_CE_BEFORE_WRITE0x000000000040LFire before write operations.

The BeforeWriteFile event will fire anytime the OS attempts to write data to a file.

FS_CE_AFTER_WRITE0x000000000080LFire after write operations.

The AfterReadFile event will fire after a write request has been processed, before the response is returned.

FS_CE_BEFORE_LOCK_CONTROL0x000000000100LFire before lock and unlock operations.

The BeforeLock, BeforeUnlockAll, BeforeUnlockAllByKey, and BeforeUnlockSingle events will fire, as applicable, before the OS attempts to lock or unlock a range of bytes in a file.

FS_CE_AFTER_LOCK_CONTROL0x000000000200LFire before and after lock and unlock operations.

The AfterLock, AfterUnlockAll, AfterUnlockAllByKey, and AfterUnlockSingle, events will fire, as applicable, after a lock or unlock request has been processed, before the response is returned.

FS_CE_BEFORE_CLEANUP0x000000000400LFire before file handle cleanup operations.

The BeforeCleanupFile event will fire anytime a process closes a file or directory handle.

FS_CE_AFTER_CLEANUP0x000000000800LFire after file handle cleanup operations.

The AfterCleanupFile event will fire after a file handle cleanup request has been processed, before the response is returned.

FS_CE_BEFORE_CLOSE0x000000001000LFire before file close operations.

The BeforeCloseFile event will fire anytime the OS closes a file or directory. Also, the AfterCloseEnumeration event will fire anytime the OS closes a directory enumeration (which typically occurs immediately before the directory is closed).

FS_CE_AFTER_CLOSE0x000000002000LFire after file close operations.

The AfterCloseFile event will fire after a file/directory close request has been processed, before the response is returned.

FS_CE_BEFORE_CAN_DELETE0x000000004000LFire before 'can be deleted' operations.

The BeforeCanFileBeDeleted event will fire anytime the OS checks whether a file or directory can be deleted.

FS_CE_AFTER_CAN_DELETE0x000000008000LFire after 'can be deleted' operations.

The AfterCanFileBeDeleted event will fire after a can be deleted request has been processed, before the response is returned.

FS_CE_BEFORE_DELETE0x000000010000LFire before delete operations

The BeforeDeleteFile event will fire anytime the OS attempts to delete a file or directory.

FS_CE_AFTER_DELETE0x000000020000LFire after delete operations.

The AfterDeleteFile event will fire after a delete request has been processed, before the response is returned.

FS_CE_BEFORE_RENAME0x000000040000LFire before rename/move operations.

The BeforeRenameOrMoveFile event will fire anytime the OS attempts to rename or move a file or directory.

FS_CE_AFTER_RENAME0x000000080000LFire after rename/move operations.

The AfterRenameOrMoveFile event will fire after a rename or move request has been processed, before the response is returned.

FS_CE_BEFORE_GET_SECURITY0x000000100000LFire before get security operations.

The BeforeGetFileSecurity event will fire before the OS queries the security attributes of a file or directory.

FS_CE_AFTER_GET_SECURITY0x000000200000LFire after get security operations.

The AfterGetFileSecurity events will fire after a get security operation has been processed, before the response is returned.

FS_CE_BEFORE_ENUMERATE_DIRECTORY0x000000400000LFire before directory enumeration operations.

The BeforeEnumerateDirectory event will fire anytime the OS needs to read information about directory entries.

FS_CE_AFTER_ENUMERATE_DIRECTORY0x000000800000LFire after directory enumeration operations.

The AfterEnumerateDirectory event will fire after information about a directory entry has been retrieved during directory enumeration, before the response is returned.

FS_CE_BEFORE_QUERY_FILE_INFO0x000001000000LFire before 'query file information' operations.

The BeforeQueryFileInfo event will fire anytime the OS needs to retrieve information about a file or directory.

FS_CE_AFTER_QUERY_FILE_INFO0x000002000000LFire after 'query file information' operations.

The AfterQueryFileInfo event will fire after a file or directory information query request has been processed, before the response is returned.

FS_CE_AFTER_GET_SIZES0x000008000000LFire after get size operations.

The AfterGetFileSizes event will fire after a file's size information is retrieved, before the response is returned.

FS_CE_BEFORE_SET_SECURITY0x000010000000LFire before set security operations.

The BeforeSetFileSecurity event will fire anytime the OS needs to change the security attributes of a file or directory.

FS_CE_AFTER_SET_SECURITY0x000020000000LFire after set security operations.

The AfterSetFileSecurity event will fire after a security attribute change request has been processed, before the response is returned.

FS_CE_BEFORE_SET_ATTRIBUTES0x000040000000LFire before file attribute update operations.

The BeforeSetFileAttributes event will fire anytime the OS attempts to change the attributes of a file or directory.

FS_CE_AFTER_SET_ATTRIBUTES0x000080000000LFire after file attribute update operations.

The AfterSetFileAttributes event will fire after a file attribute change request has been processed, before the response is returned.

FS_CE_BEFORE_SET_SIZES0x000100000000LFire before file resize operations.

The BeforeSetFileSize event will fire anytime the OS attempts to resize a file, and the BeforeSetAllocationSize event will fire anytime the OS attempts to change a file's allocation size.

FS_CE_AFTER_SET_SIZES0x000200000000LFire after file resize operations.

The AfterSetFileSize event will fire after a file resize request has been processed, and the AfterSetAllocationSize event will fire after a file allocation size change request has been processed, before the response is returned.

FS_CE_BEFORE_CREATE_HARD_LINK0x000400000000LFire before hard link creation operations.

The BeforeCreateHardLink event will fire anytime the OS attempts to create a hard link.

FS_CE_AFTER_CREATE_HARD_LINK0x000800000000LFire after hard link creation operations.

The AfterCreateHardLink events will fire after a hard link creation request has been processed, before the response is returned.

FS_CE_BEFORE_FSCTL0x001000000000LFire before FSCTL operations.

The BeforeFsctl event will fire anytime an IRP_MJ_FILE_SYSTEM_CONTROL request occurs.

FS_CE_AFTER_FSCTL0x002000000000LFire after FSCTL operations.

The AfterFsctl event will fire after an IRP_MJ_FILE_SYSTEM_CONTROL request has been processed, before the response is returned.

FS_CE_BEFORE_IOCTL0x004000000000LFire before IOCTL operations.

The BeforeIoctl event will fire anytime an IRP_MJ_DEVICE_CONTROL request occurs.

FS_CE_AFTER_IOCTL0x008000000000LFire after IOCTL operations.

The AfterIoctl event will fire after an IRP_MJ_DEVICE_CONTROL request has been processed, before the response is returned.

FS_CE_BEFORE_SET_FILE_INFO0x010000000000LFire before 'set file information' operations.

The BeforeSetFileInfo event will fire anytime the OS needs to change information about a file or directory.

FS_CE_AFTER_SET_FILE_INFO0x020000000000LFire after 'set file information' operations.

The AfterSetFileInfo event will fire after a file or directory information change request has been processed, before the response is returned.

FS_CE_BEFORE_SET_EA0x040000000000LFire before Set Extended Attributes operations.

The BeforeSetEa event will fire anytime the OS needs to set extended attributes of a file.

FS_CE_AFTER_SET_EA0x080000000000LFire after Set Extended Attributes operations.

The AfterSetEa event will fire after the OS request to set extended attributes of a file has been processed, before the response is returned.

FS_CE_BEFORE_QUERY_EA0x100000000000LFire before Query Extended Attributes operations.

The BeforeQueryEa event will fire anytime the OS needs to retrieve extended attributes of a file.

FS_CE_AFTER_QUERY_EA0x200000000000LFire after Query Extended Attributes operations.

The AfterQueryEa event will fire after the OS request to retrieve extended attributes of a file has been processed, before the response is returned.

FS_CE_BEFORE_GET_REPARSE_POINT0x400000000000LFire before Get Reparse Point operations.

The BeforeGetReparsePoint event will fire anytime the OS needs to read a reparse point of a file or directory.

FS_CE_AFTER_GET_REPARSE_POINT0x800000000000LFire after Get Reparse Point operations.

The AfterGetReparsePoint event will fire after the OS request to read a reparse point of a file or directory has been processed, before the response is returned.

FS_CE_BEFORE_SET_REPARSE_POINT0x1000000000000LFire before Set Reparse Point operations.

The BeforeSetReparsePoint event will fire anytime the OS needs to set or update a reparse point for a file or directory.

FS_CE_AFTER_SET_REPARSE_POINT0x2000000000000LFire after Set Reparse Point operations.

The AfterSetReparsePoint event will fire after the OS request to set or update a reparse point for a file or directory has been processed, before the response is returned.

FS_CE_BEFORE_DELETE_REPARSE_POINT0x4000000000000LFire before Delete Reparse Point operations.

The BeforeDeleteReparsePoint event will fire anytime the OS needs to remove reparse point information from a file or directory.

FS_CE_AFTER_DELETE_REPARSE_POINT0x8000000000000LFire after Delete Reparse Point operations.

The AfterDeleteReparsePoint event will fire after the OS request to remove reparse point information from a file or directory has been processed, before the response is returned.

FS_CE_REPARSE_FILENAME0x40000000000000LFire before various operations for the purpose of file redirection.

The ReparseFileName event will fire before any operation that includes a file or directory name, giving the application a chance to redirect it. This event is typically used when an application requires more advanced redirection logic than Reparse Rules can provide; please refer to that topic for more information.

FS_CE_REPARSE_TAG0x80000000000000LFire for reparse operations.

The ReparseWithTag event will fire anytime a file/directory open operation returns a STATUS_REPARSE result, allowing the application to handle the reparse point. Please refer to Microsoft's Reparse Points article for more information.

FS_CE_ALL-1Fire for all filesystem operations.

Control Events will fire for all filesystem operations that the component tracks.

The NotifyFlags parameter specifies which Notification Event flags should be removed from the rule. The value passed for this parameter should be constructed by ORing together zero or more of the following flags:

FS_NE_NONE0Don't fire for any filesystem operations.

Notification Events will not fire for any filesystem operations.

FS_NE_CREATE0x00000001LFire for file creation operations.

The NotifyCreateFile event will fire anytime the OS creates a file or directory. In some cases, this event can cause the NotifyOpenFile event to fire; refer to the File Create/Open Events topic for more information.

FS_NE_OPEN0x00000002LFire for file open operations.

The NotifyOpenFile event will fire anytime the OS opens a file or directory. In some cases, this event can cause the NotifyCreateFile event to fire; refer to the File Create/Open Events topic for more information.

FS_NE_READ0x00000004LFire for read operations.

The NotifyReadFile event will fire anytime the OS reads data from a file.

FS_NE_WRITE0x00000008LFire for write operations.

The NotifyWriteFile event will fire anytime the OS writes data to a file.

FS_NE_LOCK_CONTROL0x00000010LFire for lock and unlock operations.

The NotifyLock, NotifyUnlockAll, NotifyUnlockAllByKey, and NotifyUnlockSingle events will fire, as applicable, anytime the OS locks or unlocks a range of bytes in a file.

FS_NE_CLEANUP0x00000020LFire for file handle cleanup operations.

The NotifyCleanupFile event will fire anytime a process closes a file or directory handle.

FS_NE_CLOSE0x00000040LFire for file close operations.

The NotifyCloseFile event will fire anytime the OS closes a file or directory.

FS_NE_CAN_DELETE0x00000080LFire for 'can be deleted' operations.

The NotifyCanFileBeDeleted event will fire anytime the OS checks whether or not a file or directory can be deleted.

FS_NE_DELETE0x00000100LFire for delete operations.

The NotifyDeleteFile event will fire anytime the OS deletes a file or directory.

FS_NE_RENAME0x00000200LFire for rename/move operations.

The NotifyRenameOrMoveFile event will fire anytime the OS renames or moves a file or directory.

FS_NE_GET_SECURITY0x00000400LFire for get security operations.

The NotifyGetFileSecurity event will fire anytime the OS queries the security attributes of a file or directory.

FS_NE_ENUMERATE_DIRECTORY0x00000800LFire for directory enumeration operations.

The NotifyEnumerateDirectory event will fire anytime the OS retrieves a directory entry during directory enumeration.

FS_NE_QUERY_FILE_INFO0x00001000LFire for QueryFileInformation operations.

The NotifyQueryFileInfo event will fire anytime the OS retrieves information about a file or directory.

FS_NE_GET_SIZES0x00002000LFire for get size operations.

The NotifyGetFileSizes event will fire anytime the OS retrieves a file's size information.

FS_NE_SET_SECURITY0x00004000LFire for set security operations.

The NotifySetFileSecurity event will fire anytime the OS changes the security attributes of a file or directory.

FS_NE_SET_ATTRIBUTES0x00008000LFire for file attribute update operations.

The NotifySetFileAttributes event will fire anytime the OS changes the attributes of a file or directory.

FS_NE_SET_SIZES0x00010000LFire for file resize operations.

The NotifySetFileSize event will fire anytime the OS resizes a file, and the NotifySetAllocationSize event will fire anytime the OS changes a file's allocation size.

FS_NE_CREATE_HARD_LINK0x00020000LFire for hard link creation operations.

The NotifyCreateHardLink event will fire anytime the OS creates a hard link.

FS_NE_FSCTL0x00040000LFire for FSCTL operations.

The NotifyFsctl event will fire anytime an IRP_MJ_FILE_SYSTEM_CONTROL operation occurs.

FS_NE_IOCTL0x00080000LFire for IOCTL operations.

The NotifyIoctl event will fire anytime an IRP_MJ_DEVICE_CONTROL operation occurs.

FS_NE_SET_FILE_INFO0x00100000LFire for SetFileInformation operations.

The NotifySetFileInfo event will fire anytime the OS changes information about a file or directory.

FS_NE_SET_EA0x00200000LFire for Set Extended Attributes operations.

The NotifySetEa event will fire anytime the OS sets extended attributes of a file.

FS_NE_QUERY_EA0x00400000LFire for Query Extended Attributes operations.

The NotifyQueryEa event will fire anytime the OS retrieves extended attributes of a file.

FS_NE_GET_REPARSE_POINT0x00800000LFire for Get Reparse Point operations.

The NotifyGetReparsePoint event will fire anytime the OS reads reparse point information of a file or directory.

FS_NE_SET_REPARSE_POINT0x01000000LFire for Set Reparse Point operations.

The NotifySetReparsePoint event will fire anytime the OS sets or updates reparse point information for a file or directory.

FS_NE_DELETE_REPARSE_POINT0x02000000LFire for Delete Reparse Point operations.

The NotifyDeleteReparsePoint event will fire anytime the OS deletes reparse point information from a file or directory.

FS_NE_ALL-1Fire for all filesystem operations.

Notification Events will fire for all filesystem operations that the component tracks.

To delete all standard filter rules and access rules, use the DeleteAllFilterRules method instead.

Note: The methods and properties related to rule management are not intended to be used from multiple threads at once. Applications that wish to use said methods and properties from multiple threads (e.g., during the AfterFilterAttachToVolume and AfterFilterDetachFromVolume events) are responsible for employing proper thread synchronization techniques to ensure that manipulation and enumeration of the rule lists both occur in a thread-safe manner.

DeletePassthroughRule Method (CBFilter Component)

This method deletes a particular passthrough rule.

Syntax

public bool DeletePassthroughRule(string mask, int accessFlags, long controlFlags, long notifyFlags);
Public Function DeletePassthroughRule(ByVal Mask As String, ByVal AccessFlags As Integer, ByVal ControlFlags As Long, ByVal NotifyFlags As Long) As Boolean

Remarks

This method deletes the specified AccessFlags, ControlFlags, and/or NotifyFlags from the passthrough rule identified by Mask. If the aforementioned parameters include all flags currently present in the rule, then the entire rule is deleted; otherwise, the specified flags are simply removed from the rule.

If the flags or this rule are deleted successfully, this method returns true; otherwise, it returns false.

The Mask parameter must be the file mask of an existing rule. If a rule with the specified mask cannot be found, this method will fail.

The AccessFlags parameter specifies which access restrictions should be removed from the rule. The value passed for this parameter should be constructed by ORing together zero or more of the following flags:

ACCESS_NONE0x00No access restrictions.

ACCESS_READ_ONLY0x01Read-only access; writing and deleting are prohibited.

ACCESS_WRITE_ONLY0x02Write-only access; reading and deleting are prohibited.

ACCESS_DELETE_PROTECT0x04Deleting and renaming are prohibited.

ACCESS_EXECUTE_PROTECT0x08Execution is prohibited.

ACCESS_NO_CHANGE_DAC0x10Change of security attributes is prohibited.

ACCESS_NO_CHANGE_OWNER0x20Change of owner is prohibited.

ACCESS_RENAME_PROTECT0x40Renaming is prohibited.

ACCESS_DELETE_ONLY_PROTECT0x80Deleting is prohibited (renaming is not affected).

ACCESS_REMOTE_ACCESS_PROTECT0x100Access from other systems is prohibited.

ACCESS_DENY_ALL0x200All access is denied.

ACCESS_ALL_FLAGS-1Used to denote all currently set access restriction flags.

The ControlFlags parameter specifies which Control Event flags should be removed from the rule. The value passed for this parameter should be constructed by ORing together zero or more of the following flags:

FS_CE_NONE0Don't fire for any filesystem operations.

Control Events will not fire for any filesystem operations.

FS_CE_BEFORE_CREATE0x000000000001LFire before file creation operations.

The BeforeCreateFile event will fire anytime the OS attempts to create a file or directory. In some cases, this event can cause the BeforeOpenFile event to fire; refer to the File Create/Open Events topic for more information.

FS_CE_AFTER_CREATE0x000000000002LFire after file creation operations.

The AfterCreateFile event will fire after a file or directory creation request has been processed, before the response is returned. In some cases, this event can cause the AfterOpenFile event to fire; refer to the File Create/Open Events topic for more information.

FS_CE_BEFORE_OPEN0x000000000004LFire before file open operations.

The BeforeOpenFile event will fire anytime the OS attempts to open a file or directory. In some cases, this event can cause the BeforeCreateFile event to fire; refer to the File Create/Open Events topic for more information.

FS_CE_AFTER_OPEN0x000000000008LFire after file open operations.

The AfterOpenFile event will fire after a file or directory open request has been processed, before the response is returned. In some cases, this event can cause the AfterCreateFile event to fire; refer to the File Create/Open Events topic for more information.

FS_CE_BEFORE_READ0x000000000010LFire before read operations.

The BeforeReadFile event will fire anytime the OS attempts to read data from a file.

FS_CE_AFTER_READ0x000000000020LFire after read operations.

The AfterReadFile event will fire after a read request has been processed, before the response is returned.

FS_CE_BEFORE_WRITE0x000000000040LFire before write operations.

The BeforeWriteFile event will fire anytime the OS attempts to write data to a file.

FS_CE_AFTER_WRITE0x000000000080LFire after write operations.

The AfterReadFile event will fire after a write request has been processed, before the response is returned.

FS_CE_BEFORE_LOCK_CONTROL0x000000000100LFire before lock and unlock operations.

The BeforeLock, BeforeUnlockAll, BeforeUnlockAllByKey, and BeforeUnlockSingle events will fire, as applicable, before the OS attempts to lock or unlock a range of bytes in a file.

FS_CE_AFTER_LOCK_CONTROL0x000000000200LFire before and after lock and unlock operations.

The AfterLock, AfterUnlockAll, AfterUnlockAllByKey, and AfterUnlockSingle, events will fire, as applicable, after a lock or unlock request has been processed, before the response is returned.

FS_CE_BEFORE_CLEANUP0x000000000400LFire before file handle cleanup operations.

The BeforeCleanupFile event will fire anytime a process closes a file or directory handle.

FS_CE_AFTER_CLEANUP0x000000000800LFire after file handle cleanup operations.

The AfterCleanupFile event will fire after a file handle cleanup request has been processed, before the response is returned.

FS_CE_BEFORE_CLOSE0x000000001000LFire before file close operations.

The BeforeCloseFile event will fire anytime the OS closes a file or directory. Also, the AfterCloseEnumeration event will fire anytime the OS closes a directory enumeration (which typically occurs immediately before the directory is closed).

FS_CE_AFTER_CLOSE0x000000002000LFire after file close operations.

The AfterCloseFile event will fire after a file/directory close request has been processed, before the response is returned.

FS_CE_BEFORE_CAN_DELETE0x000000004000LFire before 'can be deleted' operations.

The BeforeCanFileBeDeleted event will fire anytime the OS checks whether a file or directory can be deleted.

FS_CE_AFTER_CAN_DELETE0x000000008000LFire after 'can be deleted' operations.

The AfterCanFileBeDeleted event will fire after a can be deleted request has been processed, before the response is returned.

FS_CE_BEFORE_DELETE0x000000010000LFire before delete operations

The BeforeDeleteFile event will fire anytime the OS attempts to delete a file or directory.

FS_CE_AFTER_DELETE0x000000020000LFire after delete operations.

The AfterDeleteFile event will fire after a delete request has been processed, before the response is returned.

FS_CE_BEFORE_RENAME0x000000040000LFire before rename/move operations.

The BeforeRenameOrMoveFile event will fire anytime the OS attempts to rename or move a file or directory.

FS_CE_AFTER_RENAME0x000000080000LFire after rename/move operations.

The AfterRenameOrMoveFile event will fire after a rename or move request has been processed, before the response is returned.

FS_CE_BEFORE_GET_SECURITY0x000000100000LFire before get security operations.

The BeforeGetFileSecurity event will fire before the OS queries the security attributes of a file or directory.

FS_CE_AFTER_GET_SECURITY0x000000200000LFire after get security operations.

The AfterGetFileSecurity events will fire after a get security operation has been processed, before the response is returned.

FS_CE_BEFORE_ENUMERATE_DIRECTORY0x000000400000LFire before directory enumeration operations.

The BeforeEnumerateDirectory event will fire anytime the OS needs to read information about directory entries.

FS_CE_AFTER_ENUMERATE_DIRECTORY0x000000800000LFire after directory enumeration operations.

The AfterEnumerateDirectory event will fire after information about a directory entry has been retrieved during directory enumeration, before the response is returned.

FS_CE_BEFORE_QUERY_FILE_INFO0x000001000000LFire before 'query file information' operations.

The BeforeQueryFileInfo event will fire anytime the OS needs to retrieve information about a file or directory.

FS_CE_AFTER_QUERY_FILE_INFO0x000002000000LFire after 'query file information' operations.

The AfterQueryFileInfo event will fire after a file or directory information query request has been processed, before the response is returned.

FS_CE_AFTER_GET_SIZES0x000008000000LFire after get size operations.

The AfterGetFileSizes event will fire after a file's size information is retrieved, before the response is returned.

FS_CE_BEFORE_SET_SECURITY0x000010000000LFire before set security operations.

The BeforeSetFileSecurity event will fire anytime the OS needs to change the security attributes of a file or directory.

FS_CE_AFTER_SET_SECURITY0x000020000000LFire after set security operations.

The AfterSetFileSecurity event will fire after a security attribute change request has been processed, before the response is returned.

FS_CE_BEFORE_SET_ATTRIBUTES0x000040000000LFire before file attribute update operations.

The BeforeSetFileAttributes event will fire anytime the OS attempts to change the attributes of a file or directory.

FS_CE_AFTER_SET_ATTRIBUTES0x000080000000LFire after file attribute update operations.

The AfterSetFileAttributes event will fire after a file attribute change request has been processed, before the response is returned.

FS_CE_BEFORE_SET_SIZES0x000100000000LFire before file resize operations.

The BeforeSetFileSize event will fire anytime the OS attempts to resize a file, and the BeforeSetAllocationSize event will fire anytime the OS attempts to change a file's allocation size.

FS_CE_AFTER_SET_SIZES0x000200000000LFire after file resize operations.

The AfterSetFileSize event will fire after a file resize request has been processed, and the AfterSetAllocationSize event will fire after a file allocation size change request has been processed, before the response is returned.

FS_CE_BEFORE_CREATE_HARD_LINK0x000400000000LFire before hard link creation operations.

The BeforeCreateHardLink event will fire anytime the OS attempts to create a hard link.

FS_CE_AFTER_CREATE_HARD_LINK0x000800000000LFire after hard link creation operations.

The AfterCreateHardLink events will fire after a hard link creation request has been processed, before the response is returned.

FS_CE_BEFORE_FSCTL0x001000000000LFire before FSCTL operations.

The BeforeFsctl event will fire anytime an IRP_MJ_FILE_SYSTEM_CONTROL request occurs.

FS_CE_AFTER_FSCTL0x002000000000LFire after FSCTL operations.

The AfterFsctl event will fire after an IRP_MJ_FILE_SYSTEM_CONTROL request has been processed, before the response is returned.

FS_CE_BEFORE_IOCTL0x004000000000LFire before IOCTL operations.

The BeforeIoctl event will fire anytime an IRP_MJ_DEVICE_CONTROL request occurs.

FS_CE_AFTER_IOCTL0x008000000000LFire after IOCTL operations.

The AfterIoctl event will fire after an IRP_MJ_DEVICE_CONTROL request has been processed, before the response is returned.

FS_CE_BEFORE_SET_FILE_INFO0x010000000000LFire before 'set file information' operations.

The BeforeSetFileInfo event will fire anytime the OS needs to change information about a file or directory.

FS_CE_AFTER_SET_FILE_INFO0x020000000000LFire after 'set file information' operations.

The AfterSetFileInfo event will fire after a file or directory information change request has been processed, before the response is returned.

FS_CE_BEFORE_SET_EA0x040000000000LFire before Set Extended Attributes operations.

The BeforeSetEa event will fire anytime the OS needs to set extended attributes of a file.

FS_CE_AFTER_SET_EA0x080000000000LFire after Set Extended Attributes operations.

The AfterSetEa event will fire after the OS request to set extended attributes of a file has been processed, before the response is returned.

FS_CE_BEFORE_QUERY_EA0x100000000000LFire before Query Extended Attributes operations.

The BeforeQueryEa event will fire anytime the OS needs to retrieve extended attributes of a file.

FS_CE_AFTER_QUERY_EA0x200000000000LFire after Query Extended Attributes operations.

The AfterQueryEa event will fire after the OS request to retrieve extended attributes of a file has been processed, before the response is returned.

FS_CE_BEFORE_GET_REPARSE_POINT0x400000000000LFire before Get Reparse Point operations.

The BeforeGetReparsePoint event will fire anytime the OS needs to read a reparse point of a file or directory.

FS_CE_AFTER_GET_REPARSE_POINT0x800000000000LFire after Get Reparse Point operations.

The AfterGetReparsePoint event will fire after the OS request to read a reparse point of a file or directory has been processed, before the response is returned.

FS_CE_BEFORE_SET_REPARSE_POINT0x1000000000000LFire before Set Reparse Point operations.

The BeforeSetReparsePoint event will fire anytime the OS needs to set or update a reparse point for a file or directory.

FS_CE_AFTER_SET_REPARSE_POINT0x2000000000000LFire after Set Reparse Point operations.

The AfterSetReparsePoint event will fire after the OS request to set or update a reparse point for a file or directory has been processed, before the response is returned.

FS_CE_BEFORE_DELETE_REPARSE_POINT0x4000000000000LFire before Delete Reparse Point operations.

The BeforeDeleteReparsePoint event will fire anytime the OS needs to remove reparse point information from a file or directory.

FS_CE_AFTER_DELETE_REPARSE_POINT0x8000000000000LFire after Delete Reparse Point operations.

The AfterDeleteReparsePoint event will fire after the OS request to remove reparse point information from a file or directory has been processed, before the response is returned.

FS_CE_REPARSE_FILENAME0x40000000000000LFire before various operations for the purpose of file redirection.

The ReparseFileName event will fire before any operation that includes a file or directory name, giving the application a chance to redirect it. This event is typically used when an application requires more advanced redirection logic than Reparse Rules can provide; please refer to that topic for more information.

FS_CE_REPARSE_TAG0x80000000000000LFire for reparse operations.

The ReparseWithTag event will fire anytime a file/directory open operation returns a STATUS_REPARSE result, allowing the application to handle the reparse point. Please refer to Microsoft's Reparse Points article for more information.

FS_CE_ALL-1Fire for all filesystem operations.

Control Events will fire for all filesystem operations that the component tracks.

The NotifyFlags parameter specifies which Notification Event flags should be removed from the rule. The value passed for this parameter should be constructed by ORing together zero or more of the following flags:

FS_NE_NONE0Don't fire for any filesystem operations.

Notification Events will not fire for any filesystem operations.

FS_NE_CREATE0x00000001LFire for file creation operations.

The NotifyCreateFile event will fire anytime the OS creates a file or directory. In some cases, this event can cause the NotifyOpenFile event to fire; refer to the File Create/Open Events topic for more information.

FS_NE_OPEN0x00000002LFire for file open operations.

The NotifyOpenFile event will fire anytime the OS opens a file or directory. In some cases, this event can cause the NotifyCreateFile event to fire; refer to the File Create/Open Events topic for more information.

FS_NE_READ0x00000004LFire for read operations.

The NotifyReadFile event will fire anytime the OS reads data from a file.

FS_NE_WRITE0x00000008LFire for write operations.

The NotifyWriteFile event will fire anytime the OS writes data to a file.

FS_NE_LOCK_CONTROL0x00000010LFire for lock and unlock operations.

The NotifyLock, NotifyUnlockAll, NotifyUnlockAllByKey, and NotifyUnlockSingle events will fire, as applicable, anytime the OS locks or unlocks a range of bytes in a file.

FS_NE_CLEANUP0x00000020LFire for file handle cleanup operations.

The NotifyCleanupFile event will fire anytime a process closes a file or directory handle.

FS_NE_CLOSE0x00000040LFire for file close operations.

The NotifyCloseFile event will fire anytime the OS closes a file or directory.

FS_NE_CAN_DELETE0x00000080LFire for 'can be deleted' operations.

The NotifyCanFileBeDeleted event will fire anytime the OS checks whether or not a file or directory can be deleted.

FS_NE_DELETE0x00000100LFire for delete operations.

The NotifyDeleteFile event will fire anytime the OS deletes a file or directory.

FS_NE_RENAME0x00000200LFire for rename/move operations.

The NotifyRenameOrMoveFile event will fire anytime the OS renames or moves a file or directory.

FS_NE_GET_SECURITY0x00000400LFire for get security operations.

The NotifyGetFileSecurity event will fire anytime the OS queries the security attributes of a file or directory.

FS_NE_ENUMERATE_DIRECTORY0x00000800LFire for directory enumeration operations.

The NotifyEnumerateDirectory event will fire anytime the OS retrieves a directory entry during directory enumeration.

FS_NE_QUERY_FILE_INFO0x00001000LFire for QueryFileInformation operations.

The NotifyQueryFileInfo event will fire anytime the OS retrieves information about a file or directory.

FS_NE_GET_SIZES0x00002000LFire for get size operations.

The NotifyGetFileSizes event will fire anytime the OS retrieves a file's size information.

FS_NE_SET_SECURITY0x00004000LFire for set security operations.

The NotifySetFileSecurity event will fire anytime the OS changes the security attributes of a file or directory.

FS_NE_SET_ATTRIBUTES0x00008000LFire for file attribute update operations.

The NotifySetFileAttributes event will fire anytime the OS changes the attributes of a file or directory.

FS_NE_SET_SIZES0x00010000LFire for file resize operations.

The NotifySetFileSize event will fire anytime the OS resizes a file, and the NotifySetAllocationSize event will fire anytime the OS changes a file's allocation size.

FS_NE_CREATE_HARD_LINK0x00020000LFire for hard link creation operations.

The NotifyCreateHardLink event will fire anytime the OS creates a hard link.

FS_NE_FSCTL0x00040000LFire for FSCTL operations.

The NotifyFsctl event will fire anytime an IRP_MJ_FILE_SYSTEM_CONTROL operation occurs.

FS_NE_IOCTL0x00080000LFire for IOCTL operations.

The NotifyIoctl event will fire anytime an IRP_MJ_DEVICE_CONTROL operation occurs.

FS_NE_SET_FILE_INFO0x00100000LFire for SetFileInformation operations.

The NotifySetFileInfo event will fire anytime the OS changes information about a file or directory.

FS_NE_SET_EA0x00200000LFire for Set Extended Attributes operations.

The NotifySetEa event will fire anytime the OS sets extended attributes of a file.

FS_NE_QUERY_EA0x00400000LFire for Query Extended Attributes operations.

The NotifyQueryEa event will fire anytime the OS retrieves extended attributes of a file.

FS_NE_GET_REPARSE_POINT0x00800000LFire for Get Reparse Point operations.

The NotifyGetReparsePoint event will fire anytime the OS reads reparse point information of a file or directory.

FS_NE_SET_REPARSE_POINT0x01000000LFire for Set Reparse Point operations.

The NotifySetReparsePoint event will fire anytime the OS sets or updates reparse point information for a file or directory.

FS_NE_DELETE_REPARSE_POINT0x02000000LFire for Delete Reparse Point operations.

The NotifyDeleteReparsePoint event will fire anytime the OS deletes reparse point information from a file or directory.

FS_NE_ALL-1Fire for all filesystem operations.

Notification Events will fire for all filesystem operations that the component tracks.

To delete all passthrough rules, use the DeleteAllPassthroughRules method instead.

Note: The methods and properties related to rule management are not intended to be used from multiple threads at once. Applications that wish to use said methods and properties from multiple threads (e.g., during the AfterFilterAttachToVolume and AfterFilterDetachFromVolume events) are responsible for employing proper thread synchronization techniques to ensure that manipulation and enumeration of the rule lists both occur in a thread-safe manner.

DeleteReparseRule Method (CBFilter Component)

This method deletes a particular reparse rule.

Syntax

public bool DeleteReparseRule(string mask, string productGUID);
Public Function DeleteReparseRule(ByVal Mask As String, ByVal ProductGUID As String) As Boolean

Remarks

This method deletes the ReparseRules identified by Mask and associated with the application identified by ProductGUID.

If the flags or this rule are deleted successfully, this method returns true; otherwise, it returns false.

The Mask parameter must be the file mask of an existing rule. If a rule with the specified mask cannot be found, this method will fail.

In most cases, the value passed for the ProductGUID parameter should be the same one that was used to call the Initialize method. Please refer to the AddReparseRule method's documentation for more information.

To delete all reparse rules, use the DeleteAllReparseRules method instead.

Note: The methods and properties related to rule management are not intended to be used from multiple threads at once. Applications that wish to use said methods and properties from multiple threads (e.g., during the AfterFilterAttachToVolume and AfterFilterDetachFromVolume events) are responsible for employing proper thread synchronization techniques to ensure that manipulation and enumeration of the rule lists both occur in a thread-safe manner.

FileMatchesMask Method (CBFilter Component)

This method checks whether a particular file or directory name matches the specified mask.

Syntax

public bool FileMatchesMask(string mask, string fileName, bool caseSensitive);
Public Function FileMatchesMask(ByVal Mask As String, ByVal FileName As String, ByVal CaseSensitive As Boolean) As Boolean

Remarks

This method checks whether the file or directory name specified by FileName matches Mask; if it does, this method returns true. The CaseSensitive parameter controls whether a case-sensitive match should be performed.

Note: This method does not handle so-called DOS_* wildcards (DOS_STAR, DOS_QM, DOS_DOT). The explanation about the characters can be found in the MSDN article. If you have a mask that includes one of those characters on Windows, you can use the RtlIsNameInExpression function of Windows API.

Note: As the explanation states, "When you do a case-insensitive search and do not provide a translation table, the name is converted to uppercase."

GetDriverStatus Method (CBFilter Component)

This method retrieves the status of the component's system driver.

Syntax

public int GetDriverStatus(string productGUID);
Public Function GetDriverStatus(ByVal ProductGUID As String) As Integer

Remarks

This method retrieves the status of the component's system driver. This status can then be used to verify whether it has been properly installed and is ready for use.

The value returned by the method corresponds to the dwCurrentState field of the SERVICE_STATUS structure from the Windows API. It will be one of the following:

MODULE_STATUS_NOT_PRESENT0x00000000The specified module is not present on the system.

MODULE_STATUS_STOPPED0x00000001The specified module is in the Stopped state.

MODULE_STATUS_RUNNING0x00000004The specified module is loaded and running.

ProductGUID is used to distinguish among driver installations performed by different applications. Such information is necessary to guard against unexpected situations, such as the driver being uninstalled by one application despite other applications still needing it.

Therefore, to ensure proper operation, it is critical that each individual application have its own unique ProductGUID value, and that applications (and their installation scripts) use that value when calling any of the following methods:

This method is available in both the component API and the Installer DLL included with the product; please refer to the Driver Installation topic for more information about the latter.

Note: This method cannot be called within events.

GetDriverVersion Method (CBFilter Component)

This method retrieves the version of the component's system driver.

Syntax

public long GetDriverVersion(string productGUID);
Public Function GetDriverVersion(ByVal ProductGUID As String) As Long

Remarks

This method retrieves the version of the component's system driver. The value is returned as a 64-bit integer composed of four 16-bit words that each correspond to a piece of the overall module version. For example, a version of 2.32.6.28 would cause the value 0x000200200006001C to be returned.

If the component's system driver is not installed, this method returns 0.

ProductGUID is used to distinguish among driver installations performed by different applications. Such information is necessary to guard against unexpected situations, such as the driver being uninstalled by one application despite other applications still needing it.

Therefore, to ensure proper operation, it is critical that each individual application have its own unique ProductGUID value, and that applications (and their installation scripts) use that value when calling any of the following methods:

This method is available in both the component API and the Installer DLL included with the product; please refer to the Driver Installation topic for more information about the latter.

Note: This method cannot be called within events.

GetEventFilename Method (CBFilter Component)

This method retrieves the name of the file or directory, to which the event applies.

Syntax

public string GetEventFilename();
Public Function GetEventFilename() As String

Remarks

This method can be called within event handlers of events, related to the file or directory operations, to retrieve the name of the file or directory, to which the operation applies. If the query fails or an event does not have an associated filename, this method returns an empty string.

GetHandleCreatorProcessId Method (CBFilter Component)

This method retrieves the Id of the process (PID) that opened the file handle.

Syntax

public int GetHandleCreatorProcessId();
Public Function GetHandleCreatorProcessId() As Integer

Remarks

This method can be called within certain events to retrieve the Id of the process (PID) that opened the file handle. If the query fails, this method returns 0.

Note: PIDs are not unique and may be reused by different processes over time (although in practice, this is uncommon).

Applications cannot use this method to retrieve information about remote processes accessing drives shared on the network. Windows does not provide such information due to the nature of remote access.

Note: This method can be called only within the AfterCreateFile and AfterOpenFile events, and must be called in the same thread that the event was originally fired on. Applications that need the information that this method returns during other events can do the following:

  1. Call this method within the AfterCreateFile or AfterOpenFile event.
  2. Store the information somewhere, and store a reference to it in the event's HandleContext parameter.
  3. In a later event, access the information through the reference stored in HandleContext.
Please refer to the Contexts topic for more information on how to use events' context parameters.

Note: This method cannot be used from CleanupContext event handlers.

GetHandleCreatorProcessName Method (CBFilter Component)

This method retrieves the name of the process that opened the file handle.

Syntax

public string GetHandleCreatorProcessName();
Public Function GetHandleCreatorProcessName() As String

Remarks

This method can be called within certain events to retrieve the name of the process that opened the file handle. If the query fails, this method returns an empty string.

Applications cannot use this method to retrieve information about remote processes accessing drives shared on the network. Windows does not provide such information due to the nature of remote access.

Note: This method can be called only within the AfterCreateFile and AfterOpenFile events, and must be called in the same thread that the event was originally fired on. Applications that need the information that this method returns during other events can do the following:

  1. Call this method within the AfterCreateFile or AfterOpenFile event.
  2. Store the information somewhere, and store a reference to it in the event's HandleContext parameter.
  3. In a later event, access the information through the reference stored in HandleContext.
Please refer to the Contexts topic for more information on how to use events' context parameters.

Note: This method cannot be used from CleanupContext event handlers.

GetHandleCreatorThreadId Method (CBFilter Component)

This method retrieves the Id of the thread that opened the file handle.

Syntax

public int GetHandleCreatorThreadId();
Public Function GetHandleCreatorThreadId() As Integer

Remarks

This method can be called within certain events to retrieve the Id of the thread that opened the file handle. If the query fails, this method returns 0.

Notes: Thread Ids are not unique and may be reused by different threads over time.

Note: This method can be called only within the AfterCreateFile and AfterOpenFile events, and must be called in the same thread that the event was originally fired on. Applications that need the information that this method returns during other events can do the following:

  1. Call this method within the AfterCreateFile or AfterOpenFile event.
  2. Store the information somewhere, and store a reference to it in the event's HandleContext parameter.
  3. In a later event, access the information through the reference stored in HandleContext.
Please refer to the Contexts topic for more information on how to use events' context parameters.

Note: This method cannot be used from CleanupContext event handlers.

GetHandleCreatorToken Method (CBFilter Component)

This method retrieves the security token associated with the process that opened the file handle.

Syntax

public long GetHandleCreatorToken();
Public Function GetHandleCreatorToken() As Long

Remarks

This method can be called within certain events to retrieve the security token associated with the process that opened the file handle. If the query fails, this method returns INVALID_HANDLE_VALUE.

The security token returned by this method can be passed to the Windows API's GetTokenInformation function to obtain more information about the process.

Note: When applications are finished using the returned security token, they must close it using the Windows API's CloseHandle function.

Network Access Notes

Applications monitoring a drive shared on the network may wish to obtain information about the network users accessing it (e.g., account names). Drives can be shared in several modes in Windows, which can affect the information retrievable via the security token this method returns:

  • Authenticated mode, in which case the network redirector (which, in general, is responsible for relaying remote drive requests to and from the system driver) will impersonate the network user, allowing that account's actual information to be retrieved.
  • Guest mode, in which case the retrievable information is for the system's GUEST account.
  • Administrative shares (those which exist by default and whose names end with '$'; e.g., C$, ADMIN$, etc.), in which case the retrievable information is for the LOCAL_SYSTEM account.

Note: This method can be called only within the AfterCreateFile and AfterOpenFile events, and must be called in the same thread that the event was originally fired on. Applications that need the information that this method returns during other events can do the following:

  1. Call this method within the AfterCreateFile or AfterOpenFile event.
  2. Store the information somewhere, and store a reference to it in the event's HandleContext parameter.
  3. In a later event, access the information through the reference stored in HandleContext.
Please refer to the Contexts topic for more information on how to use events' context parameters.

Note: This method cannot be used from CleanupContext event handlers.

GetOperationTime Method (CBFilter Component)

This method returns the time at which the request was received by the filter driver.

Syntax

public DateTime GetOperationTime();
Public Function GetOperationTime() As DateTime

Remarks

This method can be called within operation-related events to retrieve the time at which the filter driver received the request. The time is recorded before an event is fired but only when the RecordOperationTime configuration setting is enabled.

The timestamps returned by this method are specified in UTC.

GetOriginatorProcessId Method (CBFilter Component)

Retrieves the Id of the process (PID) that initiated the operation.

Syntax

public int GetOriginatorProcessId();
Public Function GetOriginatorProcessId() As Integer

Remarks

This method can be called within events fired for filesystem operations to retrieve the Id of the process (PID) that initiated the operation. If the query fails, this method returns 0.

Please note that PIDs are not unique, and may be reused by different processes over time (though in practice, this is uncommon).

Applications cannot use this method to retrieve information about remote processes accessing drives shared on the network. Windows does not provide such information due to the nature of remote access.

Note: This method can be called only within events, and it must be called in the same thread that the event was originally fired on. However, it must not be called within events that work with opened files since such events can be initiated by system components (e.g., the cache manager, memory manager, etc.). If applications need the information this method returns during such events, they may do the following:

  1. Call this method within the CreateFile or OpenFile event.
  2. Store the information somewhere, and store a reference to it in the event's HandleContext parameter.
  3. In a later event, access the information via the reference stored in HandleContext.
Please refer to the Contexts topic for more information on how to use events' context parameters.

Note: Renaming and deletion of files is performed after the file is opened. Thus, access checks should be performed during file opening as described above.

Note: This method cannot be used from CleanupContext event handlers.

GetOriginatorProcessName Method (CBFilter Component)

Retrieves the name of the process that initiated the operation.

Syntax

public string GetOriginatorProcessName();
Public Function GetOriginatorProcessName() As String

Remarks

This method can be called within events fired for filesystem operations to retrieve the name of the process that initiated the operation. If the query fails, this method returns empty string.

Applications cannot use this method to retrieve information about remote processes accessing drives shared on the network. Windows does not provide such information due to the nature of remote access.

Note: This method can be called only within events, and it must be called in the same thread that the event was originally fired on. However, it must not be called within events that work with opened files since such events can be initiated by system components (e.g., the cache manager, memory manager, etc.). If applications need the information this method returns during such events, they may do the following:

  1. Call this method within the CreateFile or OpenFile event.
  2. Store the information somewhere, and store a reference to it in the event's HandleContext parameter.
  3. In a later event, access the information via the reference stored in HandleContext.
Please refer to the Contexts topic for more information on how to use events' context parameters.

Note: Renaming and deletion of files is performed after the file is opened. Thus, access checks should be performed during file opening as described above.

Note: This method cannot be used from CleanupContext event handlers.

GetOriginatorThreadId Method (CBFilter Component)

Retrieves the Id of the thread that initiated the operation.

Syntax

public int GetOriginatorThreadId();
Public Function GetOriginatorThreadId() As Integer

Remarks

This method can be called within events fired for filesystem operations to retrieve the Id of the thread that initiated the operation. If the query fails, this method returns 0.

Please note that thread Ids are not unique, and may be reused by different threads over time.

Note: This method can be called only within events, and it must be called in the same thread that the event was originally fired on. However, it must not be called within events that work with opened files since such events can be initiated by system components (e.g., the cache manager, memory manager, etc.). If applications need the information this method returns during such events, they may do the following:

  1. Call this method within the CreateFile or OpenFile event.
  2. Store the information somewhere, and store a reference to it in the event's HandleContext parameter.
  3. In a later event, access the information via the reference stored in HandleContext.
Please refer to the Contexts topic for more information on how to use events' context parameters.

Note: Renaming and deletion of files is performed after the file is opened. Thus, access checks should be performed during file opening as described above.

Note: This method cannot be used from CleanupContext event handlers.

GetOriginatorToken Method (CBFilter Component)

Retrieves the security token associated with the process that initiated the operation.

Syntax

public long GetOriginatorToken();
Public Function GetOriginatorToken() As Long

Remarks

This method can be called within synchronous, i.e., Before* and After* events fired for filesystem operations to retrieve the security token associated with the process that initiated the operation. If the query fails, this method returns INVALID_HANDLE_VALUE. Note: This method will not work properly when called from Notify* event handlers because security tokens are not kept for possible later use. If you need to obtain security information about a request, use corresponding After* events.

The security token returned by this method can be passed to the Windows API's GetTokenInformation function to obtain more information about the process.

Important: When applications are finished using the returned security token, they must close it using the Windows API's CloseHandle function.

Network Access Notes

Applications monitoring a drive shared on the network may wish to obtain information about the network users accessing it (e.g., account names). Drives can be shared in several modes in Windows, which can affect the information retrievable via the security token this method returns:

  • Authenticated mode, in which case the network redirector (which, in general, is responsible for relaying remote drive requests to and from the system driver) will impersonate the network user, allowing that account's actual information to be retrieved.
  • Guest mode, in which case the retrievable information is for the system's GUEST account.
  • Administrative shares (those which exist by default and whose names end with '$'; e.g., C$, ADMIN$, etc.), in which case the retrievable information is for the LOCAL_SYSTEM account.

Note: This method can be called only within events, and it must be called in the same thread that the event was originally fired on. However, it must not be called within events that work with opened files since such events can be initiated by system components (e.g., the cache manager, memory manager, etc.). If applications need the information this method returns during such events, they may do the following:

  1. Call this method within the CreateFile or OpenFile event.
  2. Store the information somewhere, and store a reference to it in the event's HandleContext parameter.
  3. In a later event, access the information via the reference stored in HandleContext.
Please refer to the Contexts topic for more information on how to use events' context parameters.

Note: Renaming and deletion of files is performed after the file is opened. Thus, access checks should be performed during file opening as described above.

Note: This method cannot be used from CleanupContext event handlers.

GetRemoteAccessInformation Method (CBFilter Component)

This method returns networking-related information about the operation.

Syntax

public void GetRemoteAccessInformation(ref string shareName, IntPtr clientSocketAddressBuffer, ref int clientSocketAddressBufferSize);
Public Sub GetRemoteAccessInformation(ByRef ShareName As String, ByVal ClientSocketAddressBuffer As IntPtr, ByRef ClientSocketAddressBufferSize As Integer)

Remarks

Call this method from *CreateFile/*OpenFile events to retrieve the collected networking details information related to the filesystem operation performed across the network.

Note: The information will be available only when the CollectRemoteOpenInformation configuration setting is enabled.

This method returns the contents of one of two structures, SRV_OPEN_ECP_CONTEXT or NFS_OPEN_ECP_CONTEXT. These structures contain various networking information that differs depending on the remote access type. Please refer to MSDN for additional information.

Depending on the type of remote access, the information is extracted from one of those structures. When the method returns, ShareName will contain the value of either ShareName or ExportAlias field of the corresponding structure. ClientSocketAddressBuffer will contain the value of the SocketAddress or ClientSocketAddress field of the corresponding structure. This field is a structure of the SOCKADDR_STORAGE_NFS type.

When calling the method, an application needs to prepare the buffer of the required size and specify this size of the ClientSocketAddressBuffer buffer in the ClientSocketAddressBufferSize argument.

GetReparseRuleByMask Method (CBFilter Component)

This method retrieves the reparse rule associated with the specified file mask.

Syntax

public string GetReparseRuleByMask(string mask, string productGUID);
Public Function GetReparseRuleByMask(ByVal Mask As String, ByVal ProductGUID As String) As String

Remarks

This method retrieves the reparse rule identified by Mask and associated with the application identified by ProductGUID. If such a reparse rule is found, this method returns its reparse mask (see AddReparseRule); otherwise, it returns empty string.

The Mask parameter must be the file mask of an existing rule.

In most cases, the value passed for the ProductGUID parameter should be the same one that was used to call the Initialize method.

Note: The methods and properties related to rule management are not intended to be used from multiple threads at once. Applications that wish to use said methods and properties from multiple threads (e.g., during the AfterFilterAttachToVolume and AfterFilterDetachFromVolume events) are responsible for employing proper thread synchronization techniques to ensure that manipulation and enumeration of the rule lists both occur in a thread-safe manner.

GetVolumeGUID Method (CBFilter Component)

This method retrieves the volume GUID of the device targeted by a filesystem operation.

Syntax

public string GetVolumeGUID();
Public Function GetVolumeGUID() As String

Remarks

This method can be called within events fired for filesystem operations to retrieve the volume GUID of the device targeted by the operation, returned in the Volume{xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx} format. If the query fails, this method returns an empty string.

Volume GUIDs can be used to enumerate the mounting points of a device using the Windows API's GetVolumePathNamesForVolumeName function.

Note: This method can be called only within events.

Initialize Method (CBFilter Component)

This method initializes the component.

Syntax

public void Initialize(string productGUID);
Public Sub Initialize(ByVal ProductGUID As String)

Remarks

This method initializes the component and must be called each time the application starts before attempting to call any of the component's other methods with the exception of installation-related methods.

ProductGUID is used to distinguish among driver installations performed by different applications. Such information is necessary to guard against unexpected situations, such as the driver being uninstalled by one application despite other applications still needing it.

Therefore, to ensure proper operation, it is critical that each individual application have its own unique ProductGUID value, and that applications (and their installation scripts) use that value when calling any of the following methods:

If the required driver was not installed using the Install method with the same value of ProductGUID, Initialize will return a ERROR_FILE_NOT_FOUND error (Win32 error code 2).

If the loaded kernel-mode driver is older than the user-mode API, Initialize will return a ERROR_INVALID_KERNEL_INFO_VERSION error (Win32 error code 340). In this situation, an update of the driver using the Install method is required before the component can be used.

Install Method (CBFilter Component)

This method installs (or upgrades) the component's system driver.

Syntax

public bool Install(string cabFileName, string productGUID, string pathToInstall, string altitude, int flags);
Public Function Install(ByVal CabFileName As String, ByVal ProductGUID As String, ByVal PathToInstall As String, ByVal Altitude As String, ByVal Flags As Integer) As Boolean

Remarks

This method is used to install or upgrade the component's system driver. If the system must be rebooted to complete the installation process, this method returns true; otherwise, it returns false.

Important: To upgrade the component's driver, use only the Install method. Previously installed versions of the driver should not be uninstalled first. Calling the Install method will upgrade the previously installed version.

Please refer to the Driver Installation topic for more information.

CabFileName must be the path of the cbfilter.cab file containing the component's system driver.

Note: This .cab file must remain on the target system (or be available in some other way) after installation, as it is required to uninstall the driver from the system.

ProductGUID is used to distinguish among driver installations performed by different applications. Such information is necessary to guard against unexpected situations, such as the driver being uninstalled by one application despite other applications still needing it.

Therefore, to ensure proper operation, it is critical that each individual application have its own unique ProductGUID value, and that applications (and their installation scripts) use that value when calling any of the following methods:

PathToInstall controls where the driver is installed. Pass empty string (highly recommended) to automatically install them to the appropriate Windows system directory.

Altitude specifies the driver altitude to use . During development, you can use any acceptable altitude value. For deployment, an altitude value must be assigned by Microsoft before deploying a filesystem minifilter in production. After installation, the altitude can be changed at any time using the Altitude property. Please refer to the Driver Altitudes topic for more information.

Flags specifies various installation options. It should contain zero or more of the following flags, ORed together:

INSTALL_REMOVE_OLD_VERSIONS0x00000001Uninstall drivers from previous component versions (e.g., 2017).

INSTALL_KEEP_START_TYPE0x00000002Keep the driver's current start type setting in the registry.

If this flag is not set (default), the installation logic will reset the driver's start type setting in the Windows registry to the default value. Setting this flag causes the installation logic to preserve the current value, which may be necessary if the user (or the application) set it previously.

INSTALL_REQUESTS_VIA_DRIVER_STACK0x00000004Whether internal requests to the filesystem are sent directly to the filesystem driver or through the stack of filesystem filter drivers.

This flag is applicable only for CBFilter and CBMonitor.

After installation, the effects of this flag can be changed using the SendRequestsViaDriverStack configuration setting.

INSTALL_ALWAYS_PREPARE_FILES0x00010000Whether the driver should keep track of information for files that are already open when (i.e., were opened before) the component is initialized.

This flag is applicable only for CBFilter and CBMonitor.

If this flag is set, the driver will prepare information about each file as it is opened, regardless of whether a CBFilter/CBMonitor-based application is actually running at the time. This information then allows applications to receive events for any files that are already open when the CBFilter/CBMonitor component is initialized.

Note: These preparations will slow down all file open operations; do not enable this feature unless it is actually necessary.

After installation, the effects of this flag can be changed using the AlwaysPrepareFiles configuration setting.

INSTALL_FORCE_APP_PERMISSION_CHECK0x00020000Whether the driver should require the controller process to have elevated or system privileges.

This flag is not applicable for CBProcess.

If this flag is set, the driver will verify that the controller process is a system service (or is executing with elevated privileges) anytime a file is opened. If the controller process does not meet these requirements, the file will be skipped (i.e., not filtered in any way).

Note: This additional verification will slow down all file open operations.

After installation, the effects of this flag can be changed using the ForceAppPermissionCheck configuration setting.

INSTALL_FORCE_SECURITY_CHECKS0x00040000Whether the driver should prevent the controller process from filtering files that it would not normally have access to.

This flag is not applicable for CBProcess.

If this flag is set, the driver will check the security permissions of the controller process anytime a file is opened to verify that the process has access to the file. If the controller process does not have access to the file, the file will be skipped (i.e., not filtered in any way). For example, if this flag is set and the controller process is running with limited privileges, then the driver will not allow it to filter files that require greater privileges to access.

Note: This additional verification will slow down all file open operations.

After installation, the effects of this flag can be changed using the ForceSecurityChecks configuration setting.

Note: Enabling the AlwaysPrepareFiles and/or SendRequestsViaDriverStack configuration settings before calling this method will cause the corresponding flags to be added automatically. These configuration settings can also be used to toggle the corresponding options at any time after installation.

This method is available in both the component API and the Installer DLL included with the product; please refer to the Driver Installation topic for more information about the latter.

This method requires administrative rights to execute successfully. If the user account of the process that calls this method doesn't have such rights, the call will fail with an ERROR_PRIVILEGE_NOT_HELD (0x0522) error.

Note: This method cannot be called within events.

IsFileFiltered Method (CBFilter Component)

This method checks whether a particular file or directory is covered by any filter rules.

Syntax

public bool IsFileFiltered(string fileName);
Public Function IsFileFiltered(ByVal FileName As String) As Boolean

Remarks

This method checks whether the file or directory specified by FileName is covered by any of the standard filter rules active currently (i.e., whether the component would fire its events for one or more kinds of filesystem operations performed on it). If the specified file or directory matches any of the active standard filter rules, this method returns true; otherwise, it returns false.

Applications should use this method anytime they want to create/open some file or directory from within an event handler. If this method returns true, then the file or directory must be created/opened using the component's CreateFileDirect method rather than the Windows API's CreateFile function, because the latter could trigger recursion and cause a system deadlock.

NtStatusToWin32Error Method (CBFilter Component)

This method converts a native status code to a Win32 error code.

Syntax

public int NtStatusToWin32Error(int status);
Public Function NtStatusToWin32Error(ByVal Status As Integer) As Integer

Remarks

This method converts the native status code specified by Status to a Win32 error code. If the specified native status code does not map directly to a Win32 error code, this method returns ERROR_MR_MID_NOT_FOUND (317).

ResetTimeout Method (CBFilter Component)

This method resets the timeout duration for the current event handler.

Syntax

public bool ResetTimeout(int timeout);
Public Function ResetTimeout(ByVal Timeout As Integer) As Boolean

Remarks

When event timeouts are being enforced, this method can be called within an event handler to inform the component that request processing is taking longer than expected.

If called successfully, this method returns true, and the current event handler's timeout timer is immediately reset to 0; when it reaches the number of milliseconds specified by Timeout, the driver will either "release" the underlying request and pass it onwards, or cancel it by reporting an error; whichever is most appropriate for the event in question. Please refer to the Timeouts topic for more information.

Passing 0 for Timeout disables the timeout timer for the current event handler, allowing it to take as long as it needs to complete.

Note: When several events are fired for the same file concurrently (if the SerializeAccess configuration setting is disabled), and ResetTimeout is called from one of the handlers of these events, this method will reset the timer for all currently executed event handlers.

Note: This method can be called only within events.

SetFileInformationDirect Method (CBFilter Component)

This method sets the file information of a file opened using CreateFileDirect.

Syntax

public void SetFileInformationDirect(long fileHandle, int informationClass, byte[] fileInformation);
Public Sub SetFileInformationDirect(ByVal FileHandle As Long, ByVal InformationClass As Integer, ByVal FileInformation As String)

Remarks

Applications may call this method to change various kinds of information about a file that was opened using the CreateFileDirect method.

The FileHandle parameter specifies the file that should be updated. The value passed for this parameter must be a file handle obtained from the CreateFileDirect method; please refer to its documentation for more information.

The InformationClass parameter specifies the class of information to be set. For the list of supported classes, please refer to the documentation of the Windows API's FltSetInformationFile function.

Note: Only a limited subset of classes comparing to similar functions like NtSetInformationFile or NtQueryInformationFile is supported by this function.

FileInformation is a buffer that must contain the information to be set. The exact size and format of the information depend on InformationClass and are described in the FltSetInformationFile help topic.

SetFileSizeDirect Method (CBFilter Component)

This method resizes a file by passing the request directly to the filesystem.

Syntax

public bool SetFileSizeDirect(long fileHandle, long size);
Public Function SetFileSizeDirect(ByVal FileHandle As Long, ByVal Size As Long) As Boolean

Remarks

Applications can call this method in filesystem-related event handlers to resize a file without sending the request through the filesystem filter driver stack. If the file is resized successfully, this method returns true; otherwise, it returns false.

The FileHandle parameter specifies the file that should be resized. The value passed for this parameter must be a file handle obtained from the CreateFileDirect method; please refer to its documentation for more information.

The Size parameter specifies the new file size, in bytes.

To set file allocation size or valid file length, you may use the SetFileInformationDirect method.

Note: This method can be called only within events.

ShutdownSystem Method (CBFilter Component)

Shuts down or reboots the operating system.

Syntax

public bool ShutdownSystem(string shutdownPrompt, int timeout, bool forceCloseApps, bool reboot);
Public Function ShutdownSystem(ByVal ShutdownPrompt As String, ByVal Timeout As Integer, ByVal ForceCloseApps As Boolean, ByVal Reboot As Boolean) As Boolean

Remarks

This method shuts down or (if Reboot is true) reboots the operating system. If the appropriate privileges cannot be obtained, or if the InitiateSystemShutdown system call returns false, then this method will return false; otherwise, it returns true. This method can be used if the installation or uninstallation function requires the system to be rebooted in order to complete.

ShutdownPrompt, if non-empty, specifies a message that the OS should display to the user for Timeout seconds. If empty string is passed for ShutdownPrompt, no message is displayed and the Timeout parameter's value is ignored.

ForceCloseApps specifies whether the OS should forcefully close all applications. Please keep in mind that forceful closing of applications with unsaved data can lead to data loss.

Reboot specifies whether the OS should reboot (true) or just shut down (false).

This method is available in both the component API and the Installer DLL included with the product; please refer to the Driver Installation topic for more information about the latter.

Note: This method cannot be called within events.

StartFilter Method (CBFilter Component)

This method starts filtering filesystem operations.

Syntax

public void StartFilter(int timeout);
Public Sub StartFilter(ByVal Timeout As Integer)

Remarks

This method attaches the filter, causing the component's system driver to start filtering filesystem operations according to the filter rules currently present. Rules can be added and removed both before and after this method is called, so long as the Initialize method is called before doing anything else.

The Timeout parameter specifies how many milliseconds the driver should wait for events to execute before releasing or cancelling the underlying OS requests; please refer to the Timeouts topic for more information. Valid values are 0, which disables event timeouts, and values greater than or equal to 3000. When event timeouts are in effect, event handlers can call ResetTimeout to reset the timer if they require additional time to complete.

This method can fail for a number of reasons, including (but not limited to) the following:

  • If the component's system driver has not been properly installed, or is awaiting a system reboot (as indicated by the return value of Install), this method fails with an ERROR_FILE_NOT_FOUND (2) error code.
  • If the Initialize method has not been called yet, this method fails with an ERROR_NOT_READY (21) error code.
  • If the filter is already Active, this method fails with an ERROR_CONNECTION_ACTIVE (1230) error code.
  • If an invalid value is passed for Timeout, this method fails with an ERROR_IMPLEMENTATION_LIMIT (1292) error code.

StopFilter Method (CBFilter Component)

This method stops filtering filesystem operations.

Syntax

public void StopFilter(bool reserved);
Public Sub StopFilter(ByVal Reserved As Boolean)

Remarks

This method detaches the filter, causing the component's system driver to stop filtering filesystem operations. This method will block until all pending requests have been completed and the filter has been detached.

The Reserved parameter is obsolete.

SuspendDefaultRules Method (CBFilter Component)

This method suspends all default rules until the application exits.

Syntax

public bool SuspendDefaultRules(string productGUID);
Public Function SuspendDefaultRules(ByVal ProductGUID As String) As Boolean

Remarks

This method suspends (i.e., deactivates) all default rules associated with the application identified by ProductGUID until the application exits. If the rules are suspended successfully, this method returns true; otherwise, it returns false.

In most cases, the value passed for the ProductGUID parameter should be the same one that was used to call the Initialize method.

When the application exits, the component's system driver will reactivate the suspended rules and start enforcing them once again.

SuspendFileEvents Method (CBFilter Component)

This method suspends all events for a particular file or directory until all of its handles have been closed.

Syntax

public void SuspendFileEvents();
Public Sub SuspendFileEvents()

Remarks

Applications can call this method from an AfterCreateFile or AfterOpenFile event to suspend all further events for the file or directory that the event fired for. The suspension will remain in effect until all handles to said file or directory have been closed, at which point the component will once again fire events for it (if it is accessed again).

Typically, this method should be used only as a "last resort"; that is, when the application cannot achieve the same outcome through the use of more granular standard filter rules. Said another way, it is almost always more efficient for an application to exclude files or directories implicitly using standard filter rules, if possible, than it is to exclude them explicitly using this method.

Note: This method can be called only within the AfterCreateFile and AfterOpenFile events.

ToggleProcessProtection Method (CBFilter Component)

This method enables or disables termination protection for the application.

Syntax

public bool ToggleProcessProtection(bool enabled);
Public Function ToggleProcessProtection(ByVal Enabled As Boolean) As Boolean

Remarks

This method controls the termination protection mechanism, which applications can enable to prevent their process and threads from being terminated. If successful, this method returns true; otherwise, it returns false.

The Enabled parameter specifies whether termination protection should be enabled (true) or disabled (false); it is disabled by default. If termination protection is enabled, an application must disable it before attempting to exit.

Note: When developing a GUI-based application, please keep in mind that the termination protection mechanism does not intercept Windows' notifications like WM_CLOSE or WM_QUIT; applications must intercept and handle such messages themselves if they wish to protect their UI. Please refer to Microsoft's Window Notifications articles for more information.

Uninstall Method (CBFilter Component)

This method uninstalls the component's system driver.

Syntax

public bool Uninstall(string cabFileName, string productGUID, string installedPath, int flags);
Public Function Uninstall(ByVal CabFileName As String, ByVal ProductGUID As String, ByVal InstalledPath As String, ByVal Flags As Integer) As Boolean

Remarks

This method is used to uninstall the component's system driver. If the system must be rebooted to complete the uninstallation process, this method returns true; otherwise, it returns false.

Important: To upgrade the component's driver, use only the Install method. Previously installed versions of the driver should not be uninstalled first. Calling the Install method will upgrade the previously installed version.

Please refer to the Driver Installation topic for more information.

The same values must be passed for the CabFileName, ProductGUID, and InstalledPath parameters as were passed when Install was called; please refer to its documentation for more information.

Flags specifies which versions of the component's system driver should be uninstalled and which should be set by ORing together one or more of the following values:

UNINSTALL_VERSION_PREVIOUS0x00000001Uninstall modules from previous product versions.

UNINSTALL_VERSION_CURRENT0x00000002Uninstall modules from the current product version.

UNINSTALL_VERSION_ALL0x00000003Uninstall modules from all product versions.

This method is available in both the component API and the Installer DLL included with the product; please refer to the Driver Installation topic for more information about the latter.

This method requires administrative rights to execute successfully. If the user account of the process that calls this method doesn't have such rights, the call will fail with an ERROR_PRIVILEGE_NOT_HELD (0x0522) error.

Note: This method cannot be called within events.

AfterCanFileBeDeleted Event (CBFilter Component)

This event fires after the OS marks a file or directory for deletion or removes such a mark.

Syntax

public event OnAfterCanFileBeDeletedHandler OnAfterCanFileBeDeleted;

public delegate void OnAfterCanFileBeDeletedHandler(object sender, CbfilterAfterCanFileBeDeletedEventArgs e);

public class CbfilterAfterCanFileBeDeletedEventArgs : EventArgs {
  public string FileName { get; }
  public int RequestType { get; }
  public bool CanDelete { get; }
  public int Status { get; set; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnAfterCanFileBeDeleted As OnAfterCanFileBeDeletedHandler

Public Delegate Sub OnAfterCanFileBeDeletedHandler(sender As Object, e As CbfilterAfterCanFileBeDeletedEventArgs)

Public Class CbfilterAfterCanFileBeDeletedEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public ReadOnly Property RequestType As Integer
  Public ReadOnly Property CanDelete As Boolean
  Public Property Status As Integer
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ResultCode As Integer
End Class

Remarks

This event fires after the OS marks the file or directory specified by FileName for deletion or removes such a mark.

If the file or directory is marked for deletion, they will not be removed immediately but will actually be removed when the last handle is closed. Moreover, it is possible that a future call to a system function will remove the mark, so this event is not a final indicator that the file or directory will be deleted.

Files and directories can be deleted in two ways: (1) a file or directory can be opened with the FILE_FLAG_DELETE_ON_CLOSE flag, or (2) some process may call Windows API's NtSetInformationFile function with FILE_DISPOSITION_INFORMATION or FILE_DISPOSITION_INFORMATION_EX structure as a parameter.

If the file or directory is created or opened with the FILE_FLAG_DELETE_ON_CLOSE flag, this event is fired shortly after the AfterCreateFile or AfterOpenFile event.

The RequestType indicates which kind of system request resulted in firing this event. It can be one of the following:

DEL_REQ_OPEN_FLAG0x1The file or directory is opened with the FILE_FLAG_DELETE_ON_CLOSE flag

DEL_REQ_SET_DISPOSITION0x2The system has sent the IRP_MJ_SET_INFORMATION request with SetFileDisposition structure as a parameter.

This request usually is sent using the NtSetInformationFile() Windows native API function.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_AFTER_CAN_DELETE flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The CanDelete parameter reflects whether the file or directory will be deleted.

The Status parameter contains an NT status code that indicates the outcome of the operation; 0 indicates success. To convert this value to a Win32 error code, call the NtStatusToWin32Error method.

Note: This event will not fire for failed requests unless the ProcessFailedRequests property is enabled. Applications may change this parameter's value if they want a different NT status code to be returned.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

AfterCleanupFile Event (CBFilter Component)

This event fires after a file or directory handle is closed.

Syntax

public event OnAfterCleanupFileHandler OnAfterCleanupFile;

public delegate void OnAfterCleanupFileHandler(object sender, CbfilterAfterCleanupFileEventArgs e);

public class CbfilterAfterCleanupFileEventArgs : EventArgs {
  public string FileName { get; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnAfterCleanupFile As OnAfterCleanupFileHandler

Public Delegate Sub OnAfterCleanupFileHandler(sender As Object, e As CbfilterAfterCleanupFileEventArgs)

Public Class CbfilterAfterCleanupFileEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ResultCode As Integer
End Class

Remarks

This event fires after a handle to the file or directory specified by FileName is closed. This event differs from AfterCloseFile in that AfterCleanupFile fires immediately after an open handle to the specified file or directory is closed by a process, whereas AfterCloseFile may be fired much later when the OS decides that the file or directory can be formally closed.

Other events may fire for the file or directory in the time between when this event fires and when the AfterCloseFile event fires. For example, system components, such as the memory manager or cache manager, may cause the AfterReadFile and AfterWriteFile events to fire.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_AFTER_CLEANUP flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

AfterCloseEnumeration Event (CBFilter Component)

This event fires after a directory enumeration operation finishes.

Syntax

public event OnAfterCloseEnumerationHandler OnAfterCloseEnumeration;

public delegate void OnAfterCloseEnumerationHandler(object sender, CbfilterAfterCloseEnumerationEventArgs e);

public class CbfilterAfterCloseEnumerationEventArgs : EventArgs {
  public string DirectoryName { get; }
  public IntPtr DirectoryContext { get; }
  public IntPtr HandleContext { get; }
  public IntPtr EnumerationContext { get; }
  public int ResultCode { get; set; }
}
Public Event OnAfterCloseEnumeration As OnAfterCloseEnumerationHandler

Public Delegate Sub OnAfterCloseEnumerationHandler(sender As Object, e As CbfilterAfterCloseEnumerationEventArgs)

Public Class CbfilterAfterCloseEnumerationEventArgs Inherits EventArgs
  Public ReadOnly Property DirectoryName As String
  Public ReadOnly Property DirectoryContext As IntPtr
  Public ReadOnly Property HandleContext As IntPtr
  Public ReadOnly Property EnumerationContext As IntPtr
  Public Property ResultCode As Integer
End Class

Remarks

This event fires after enumeration of the directory specified by DirectoryName finishes.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_BEFORE_CLOSE flag (directory enumerations are typically closed immediately before a directory is closed).

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The EnumerationContext parameter is a placeholder for application-defined data associated with the enumeration. Please refer to the Contexts topic for more information.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

AfterCloseFile Event (CBFilter Component)

This event fires after a file or directory is closed.

Syntax

public event OnAfterCloseFileHandler OnAfterCloseFile;

public delegate void OnAfterCloseFileHandler(object sender, CbfilterAfterCloseFileEventArgs e);

public class CbfilterAfterCloseFileEventArgs : EventArgs {
  public string FileName { get; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnAfterCloseFile As OnAfterCloseFileHandler

Public Delegate Sub OnAfterCloseFileHandler(sender As Object, e As CbfilterAfterCloseFileEventArgs)

Public Class CbfilterAfterCloseFileEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ResultCode As Integer
End Class

Remarks

This event fires after the file or directory specified by FileName is closed.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_AFTER_CLOSE flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information.

If the file or directory was marked for deletion earlier, the AfterDeleteFile will fire shortly before this event.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

AfterCreateFile Event (CBFilter Component)

This event fires after a file or directory is created.

Syntax

public event OnAfterCreateFileHandler OnAfterCreateFile;

public delegate void OnAfterCreateFileHandler(object sender, CbfilterAfterCreateFileEventArgs e);

public class CbfilterAfterCreateFileEventArgs : EventArgs {
  public string FileName { get; }
  public int ExistingAttributes { get; }
  public bool Isolate { get; }
  public string BackendFileName { get; }
  public int DesiredAccess { get; }
  public int Attributes { get; }
  public int ShareMode { get; }
  public int Options { get; }
  public int CreateDisposition { get; }
  public IntPtr SecurityDescriptor { get; }
  public int Length { get; }
  public int Status { get; set; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnAfterCreateFile As OnAfterCreateFileHandler

Public Delegate Sub OnAfterCreateFileHandler(sender As Object, e As CbfilterAfterCreateFileEventArgs)

Public Class CbfilterAfterCreateFileEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public ReadOnly Property ExistingAttributes As Integer
  Public ReadOnly Property Isolate As Boolean
  Public ReadOnly Property BackendFileName As String
  Public ReadOnly Property DesiredAccess As Integer
  Public ReadOnly Property Attributes As Integer
  Public ReadOnly Property ShareMode As Integer
  Public ReadOnly Property Options As Integer
  Public ReadOnly Property CreateDisposition As Integer
  Public ReadOnly Property SecurityDescriptor As IntPtr
  Public ReadOnly Property Length As Integer
  Public Property Status As Integer
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ResultCode As Integer
End Class

Remarks

This event fires after the file or directory specified by FileName is created. Please refer to the File Create/Open Events topic for more information about how the component determines whether to fire this event or AfterOpenFile.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_AFTER_CREATE flag.

Note: Applications must have the FilterOwnRequests configuration setting enabled if they wish to filter their own file/directory creation requests.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

When extended rules are used or the AlwaysRequestAttributesOnOpen configuration setting is enabled, the driver requests attributes of the entity from the filesystem and passes them to ExistingAttributes. If the attributes are not requested, this parameter contains 0.

Isolation-related functionality is under construction.

The DesiredAccess, Attributes, ShareMode, and CreateDisposition parameters reflect the values that were passed for the similarly named parameters of the Windows API's CreateFile function (or, more accurately, the values carried by the IRP_MJ_CREATE IRP).

DesiredAccess may contain one or more of the following access flags:

DESIRED_ACCESS_FILE_LIST_DIRECTORY0x00000001For a directory, the right to list the contents of the directory.

DESIRED_ACCESS_FILE_READ_DATA0x00000001For a file object, the right to read the corresponding file data.

For a directory object, the right to read the corresponding directory data.

DESIRED_ACCESS_FILE_ADD_FILE0x00000002For a directory, the right to create a file in the directory.

DESIRED_ACCESS_FILE_WRITE_DATA0x00000002For a file object, the right to write data to the file.

For a directory object, the right to create a file in the directory

DESIRED_ACCESS_FILE_ADD_SUBDIRECTORY0x00000004For a directory, the right to create a subdirectory.

DESIRED_ACCESS_FILE_APPEND_DATA0x00000004For a file object, the right to append data to the file.

(For local files, write operations will not overwrite existing data if this flag is specified without FILE_WRITE_DATA.) For a directory object, the right to create a subdirectory (FILE_ADD_SUBDIRECTORY).

DESIRED_ACCESS_FILE_READ_EA0x00000008The right to read extended file attributes.

DESIRED_ACCESS_FILE_WRITE_EA0x00000010The right to write extended file attributes.

DESIRED_ACCESS_FILE_EXECUTE0x00000020For a native code file, the right to execute the file.

This access right given to scripts may cause the script to be executable, depending on the script interpreter.

DESIRED_ACCESS_FILE_DELETE_CHILD0x00000040For a directory, the right to delete a directory and all the files it contains, including read-only files.

DESIRED_ACCESS_FILE_READ_ATTRIBUTES0x00000080The right to read file attributes.

DESIRED_ACCESS_FILE_WRITE_ATTRIBUTES0x00000100The right to write file attributes.

DESIRED_ACCESS_READ_CONTROL0x00020000The right to read the information in the file or directory object's security descriptor.

This does not include the information in the SACL.

DESIRED_ACCESS_STANDARD_RIGHTS_READ0x00020000Includes READ_CONTROL, which is the right to read the information in the file or directory object's security descriptor.

This does not include the information in the SACL.

DESIRED_ACCESS_STANDARD_RIGHTS_WRITE0x00020000Same as STANDARD_RIGHTS_READ

DESIRED_ACCESS_STANDARD_RIGHTS_EXECUTE0x00020000Same as STANDARD_RIGHTS_READ

DESIRED_ACCESS_SYNCHRONIZE0x00100000The right to use the object for synchronization.

This enables a thread to wait until the object is in the signaled state. Some object types do not support this access right.

DESIRED_ACCESS_FILE_ALL_ACCESS0x001F01FFAll possible access rights for a file.

DESIRED_ACCESS_FILE_GENERIC_READ0x00120089A combinarion of flags that allow reading of the file.

Note: Don't match received values against this flag. Instead, use flags that specify the rights that you want to verify or add/remove.

DESIRED_ACCESS_FILE_GENERIC_WRITE0x00120116A combinarion of flags that allow modifications to the file.

Note: Don't match received values against this flag. Instead, use flags that specify the rights that you want to verify or add/remove.

DESIRED_ACCESS_FILE_GENERIC_EXECUTE0x001200A0A combinarion of flags that allow execution of the file.

Note: Don't match received values against this flag. Instead, use flags that specify the rights that you want to verify or add/remove.

Attributes may contain one or more of the following attributes:

FILE_SYS_ATTR_READ_ONLY0x00000001The file is read-only.

Applications can read the file, but cannot write to it or delete it. This attribute is not honored on directories.

FILE_SYS_ATTR_HIDDEN0x00000002The file or directory is hidden.

The file is not included in an ordinary directory listing.

FILE_SYS_ATTR_SYSTEM0x00000004A file or directory that the operating system uses a part of, or uses exclusively.

FILE_SYS_ATTR_DIRECTORY0x00000010The entry is a directory.

FILE_SYS_ATTR_ARCHIVE0x00000020The entry is an archive file or directory.

Applications typically use this attribute to mark files for backup or removal.

FILE_SYS_ATTR_NORMAL0x00000080A file doesn't have other attributes set.

This attribute is valid only when used alone.

FILE_SYS_ATTR_TEMPORARY0x00000100A file that is being used for temporary storage.

File systems avoid writing data back to mass storage if sufficient cache memory is available, because typically, an application deletes a temporary file after the handle is closed. In that scenario, the system can entirely avoid writing the data. Otherwise, the data are written after the handle is closed.

FILE_SYS_ATTR_SPARSE_FILE0x00000200A file that is a sparse file.

FILE_SYS_ATTR_REPARSE_POINT0x00000400A file that is a reparse point or a symbolic link.

FILE_SYS_ATTR_COMPRESSED0x00000800A file or directory that is compressed.

For a file, all of the data in the file are compressed. For a directory, compression is the default for newly created files and subdirectories. A filesystem implementation can make use of this attribute by setting the SupportCompressedAttribute property to true and then properly handling the GetFileInfo, EnumerateDirectory, and SetFileAttributes events.

FILE_SYS_ATTR_OFFLINE0x00001000The data of a file are not available immediately.

This attribute indicates that the file data are physically moved to offline storage.

FILE_SYS_ATTR_NOT_CONTENT_INDEXED0x00002000The file or directory is not to be indexed by the content indexing service.

FILE_SYS_ATTR_ENCRYPTED0x00004000A file or directory that is encrypted.

For a file, all data streams in the file are encrypted. For a directory, encryption is the default for newly created files and subdirectories.

Note: This flag is used by NTFS and the OS sends undocumented requests to the filesystem based on this flag. The flag should not be used for files in custom filesystem implementations.

FILE_SYS_ATTR_VIRTUAL0x00010000Reserved.

Note: This flag is reserved by the OS and should not be used for files in custom filesystem implementations.

FILE_SYS_ATTR_RECALL_ON_OPEN0x00040000The file or directory has no physical representation on the local system; the item is virtual.

Opening the item will be more expensive than normal (e.g., it will cause at least some of it to be fetched from a remote store). This flag is reported by filesystems during directory enumerations.

ShareMode may contain zero or more of the following share mode flags:

FILESYS_SHARE_READ0x00000001Enables subsequent open operations on a file or device to request read access.

Enables subsequent open operations to request read access; otherwise, no process can open the file or device if it requests read access. If this flag is not specified, but the file or device has been opened for read access, the function fails.

FILESYS_SHARE_WRITE0x00000002Enables subsequent open operations on a file or device to request write access.

Enables subsequent open operations to request write access; otherwise, no process can open the file or device if it requests write access. If this flag is not specified, but the file or device has been opened for write access or has a file mapping with write access, the function fails.

FILESYS_SHARE_DELETE0x00000004Enables subsequent open operations on a file or device to request delete access.

Enables subsequent open operations to request delete access; otherwise, no process can open the file or device if it requests delete access. If this flag is not specified, but the file or device has been opened for delete access, the function fails.

Note: Delete access allows both delete and rename operations.

CreateDisposition may contain one of the following values:

FILE_DISPOSITION_CREATE_NEW0x00000001Creates a new file, only if it does not already exist.

If the specified file exists, the operation fails with an "already exists" error.

FILE_DISPOSITION_CREATE_ALWAYS0x00000002Creates a new file, always.

If the specified file exists and is writable, the system overwrites the file. If the specified file does not exist and is a valid path, a new file is created.

FILE_DISPOSITION_OPEN_EXISTING0x00000003Opens a file, only if it exists

If the specified file does not exist, opening fails.

FILE_DISPOSITION_OPEN_ALWAYS0x00000004Opens a file, always.

If the specified file exists, the operation succeeds. If the specified file does not exist and is a valid path to a writable location, the a file is created.

FILE_DISPOSITION_TRUNCATE_EXISTING0x00000005Opens a file and truncates it so that its size is zero bytes, only if it exists.

If the specified file does not exist, the operation fails with a "file not found" error.

Options contains the flags that are described in the CreateOptions parameter of the native API's ZwCreateFile function. Most of those flags correspond to flags passed in the FlagsAndAttributes parameter of the Windows API's CreateFile function, but some flags are specific to the native API. If you need those flags, check both functions' descriptions.

Please refer to Microsoft's documentation for detailed information about these constants.

To determine whether the request was for a file or a directory, compare Attributes against the FILE_SYS_ATTR_DIRECTORY constant, as follows: // Check whether the request is for a file or a directory. bool isDirectory = Attributes & FILE_SYS_ATTR_DIRECTORY == FILE_SYS_ATTR_DIRECTORY; FILE_SYS_ATTR_DIRECTORY will be present if it was specified by the calling process or if the existing filesystem entry is a directory.

To determine whether a file will be deleted when its last handle is closed, compare Options against the Windows API's FILE_FLAG_DELETE_ON_CLOSE constant, as follows: // Check whether the file will be deleted on close. bool deleteOnClose = Options & FILE_FLAG_DELETE_ON_CLOSE == FILE_FLAG_DELETE_ON_CLOSE; Note: Because files can be deleted in different ways, do not use this check to take actions related to tracking file deletion operations. Instead, use the events related to file deletion.

When a file or directory is created using the CreateFile() Windows API function, a caller can specify the security descriptor with the security information. This security information should be applied to a newly created file or directory. The component passes this security information in the SecurityInformation and SecurityDescriptor parameters, when the PassSecurityInFileOpenEvents configuration setting is enabled. If this configuration setting is omitted, the corresponding parameters are empty.

The SecurityInformation parameter reflects which pieces of security information, of those present in SecurityDescriptor, are valid and should have been applied. Please refer to Microsoft's SECURITY_INFORMATION data type documentation for more information about possible values.

The SecurityDescriptor parameter points to a memory buffer that contains the security information. The Length parameter reflects the length of this data, in bytes. Please see the Buffer Parameters topic for more information on how to work with memory buffer event parameters.

The data are formatted as a SECURITY_DESCRIPTOR structure in self-relative format; please refer to the Microsoft's documentation for more information.

If the Options contains the FILE_FLAG_DELETE_ON_CLOSE flag, the AfterCanFileBeDeleted event will fire after this event.

If the file is created with Extended Attributes passed in the request, the AfterSetEa event will fire after this event.

The Status parameter contains an NT status code that indicates the outcome of the operation; 0 indicates success. To convert this value to a Win32 error code, call the NtStatusToWin32Error method.

Note: This event will not fire for failed requests unless the ProcessFailedRequests property is enabled. Applications may change this parameter's value if they want a different NT status code to be returned.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information.

When the ProcessFailedRequests property is enabled, this event may fire even if the specified file or directory has not been created or opened, in which case the Status parameter will be non-zero. When this occurs, applications must not alter the FileContext and HandleContext parameters.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

AfterCreateHardLink Event (CBFilter Component)

This event fires after a hard link is created.

Syntax

Remarks

This event fires after a hard link to the file specified by FileName is created. Please refer to Microsoft's Hard Links article for more information about hard links.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_AFTER_CREATE_HARD_LINK flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The LinkName parameter reflects the name of the created hard link.

The Status parameter contains an NT status code that indicates the outcome of the operation; 0 indicates success. To convert this value to a Win32 error code, call the NtStatusToWin32Error method.

Note: This event will not fire for failed requests unless the ProcessFailedRequests property is enabled. Applications may change this parameter's value if they want a different NT status code to be returned.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

AfterDeleteFile Event (CBFilter Component)

This event fires after a file or directory is deleted.

Syntax

public event OnAfterDeleteFileHandler OnAfterDeleteFile;

public delegate void OnAfterDeleteFileHandler(object sender, CbfilterAfterDeleteFileEventArgs e);

public class CbfilterAfterDeleteFileEventArgs : EventArgs {
  public string FileName { get; }
  public int RequestType { get; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnAfterDeleteFile As OnAfterDeleteFileHandler

Public Delegate Sub OnAfterDeleteFileHandler(sender As Object, e As CbfilterAfterDeleteFileEventArgs)

Public Class CbfilterAfterDeleteFileEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public ReadOnly Property RequestType As Integer
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ResultCode As Integer
End Class

Remarks

This event fires after the file or directory specified by FileName is deleted. More specifically, this event is fired after the final IRP_MJ_CLOSE IRP is processed by the filesystem (i.e., after the last handle to the file or directory is closed and the file or directory is gone) and before AfterCloseFile fires.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_AFTER_DELETE flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The RequestType indicates which kind of system request resulted in firing this event. It can be one of the following:

DEL_REQ_OPEN_FLAG0x1The file or directory is opened with the FILE_FLAG_DELETE_ON_CLOSE flag

DEL_REQ_SET_DISPOSITION0x2The system has sent the IRP_MJ_SET_INFORMATION request with SetFileDisposition structure as a parameter.

This request usually is sent using the NtSetInformationFile() Windows native API function.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

AfterDeleteReparsePoint Event (CBFilter Component)

This event fires after the OS deletes a reparse point from a file or directory.

Syntax

public event OnAfterDeleteReparsePointHandler OnAfterDeleteReparsePoint;

public delegate void OnAfterDeleteReparsePointHandler(object sender, CbfilterAfterDeleteReparsePointEventArgs e);

public class CbfilterAfterDeleteReparsePointEventArgs : EventArgs {
  public string FileName { get; }
  public IntPtr ReparseBuffer { get; }
  public int BufferLength { get; }
  public int Status { get; set; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnAfterDeleteReparsePoint As OnAfterDeleteReparsePointHandler

Public Delegate Sub OnAfterDeleteReparsePointHandler(sender As Object, e As CbfilterAfterDeleteReparsePointEventArgs)

Public Class CbfilterAfterDeleteReparsePointEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public ReadOnly Property ReparseBuffer As IntPtr
  Public ReadOnly Property BufferLength As Integer
  Public Property Status As Integer
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ResultCode As Integer
End Class

Remarks

This event fires after the OS deletes a reparse point from a file or directory specified by FileName.

Note: The file or directory is not deleted, only a reparse point is.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_AFTER_DELETE_REPARSE_POINT flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The ReparseBuffer parameter points to a memory buffer that specifies the known reparse point information. This information is provided for convenience. Please see the Buffer Parameters topic for more information on how to work with memory buffer event parameters.

Please refer to the Reparse Points topic for more information.

The Status parameter contains an NT status code that indicates the outcome of the operation; 0 indicates success. To convert this value to a Win32 error code, call the NtStatusToWin32Error method.

Note: This event will not fire for failed requests unless the ProcessFailedRequests property is enabled. Applications may change this parameter's value if they want a different NT status code to be returned.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

AfterEnumerateDirectory Event (CBFilter Component)

This event fires after a directory entry is returned during directory enumeration.

Syntax

public event OnAfterEnumerateDirectoryHandler OnAfterEnumerateDirectory;

public delegate void OnAfterEnumerateDirectoryHandler(object sender, CbfilterAfterEnumerateDirectoryEventArgs e);

public class CbfilterAfterEnumerateDirectoryEventArgs : EventArgs {
  public string DirectoryName { get; }
  public int Flags { get; }
  public int Index { get; }
  public string FileName { get; set; }
  public DateTime CreationTime { get; set; }
  public DateTime LastAccessTime { get; set; }
  public DateTime LastWriteTime { get; set; }
  public DateTime ChangeTime { get; set; }
  public long Size { get; set; }
  public long AllocationSize { get; set; }
  public long FileId { get; set; }
  public int Attributes { get; set; }
  public int Status { get; set; }
  public IntPtr DirectoryContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public IntPtr EnumerationContext { get; set; }
  public bool ProcessRequest { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnAfterEnumerateDirectory As OnAfterEnumerateDirectoryHandler

Public Delegate Sub OnAfterEnumerateDirectoryHandler(sender As Object, e As CbfilterAfterEnumerateDirectoryEventArgs)

Public Class CbfilterAfterEnumerateDirectoryEventArgs Inherits EventArgs
  Public ReadOnly Property DirectoryName As String
  Public ReadOnly Property Flags As Integer
  Public ReadOnly Property Index As Integer
  Public Property FileName As String
  Public Property CreationTime As DateTime
  Public Property LastAccessTime As DateTime
  Public Property LastWriteTime As DateTime
  Public Property ChangeTime As DateTime
  Public Property Size As Long
  Public Property AllocationSize As Long
  Public Property FileId As Long
  Public Property Attributes As Integer
  Public Property Status As Integer
  Public Property DirectoryContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property EnumerationContext As IntPtr
  Public Property ProcessRequest As Boolean
  Public Property ResultCode As Integer
End Class

Remarks

This event fires after a directory entry (i.e., a file or subdirectory) is returned during enumeration of the directory specified by DirectoryName.

Applications may use this event to modify the entry's metadata before it gets reported to the requestor or even to prevent the entry from being reported in the first place.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_AFTER_ENUMERATE_DIRECTORY flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The Flags parameter specifies supplementary information about enumeration. It is a combination of zero or more values:

FS_ENUM_RESTART_SCAN1The requestor specified that directory enumeration must be restarted.

FS_ENUM_RETURN_SINGLE_ENTRY2One entry should be returned.

FS_ENUM_INDEX_SPECIFIED4The requestor specified the index to start enumeration from.

If the Flags parameter contains FS_ENUM_INDEX_SPECIFIED, the Index parameter contains the index as provided by the OS.

The FileName parameter reflects the name of the directory entry. .

The CreationTime, LastAccessTime, LastWriteTime, and ChangeTime parameters specify the entry's time values, specified in UTC.

The Size parameter specifies the size of the file, in bytes; it must always be 0 for subdirectories.

The AllocationSize parameter specifies the amount of space allocated for the file, in bytes; it must always be 0 for subdirectories.

The FileId parameter specifies the unique Id of the entry, as reported by the filesystem (or, for virtual files, by the application itself). This Id is used by the network redirector, and some third-party applications, to open files and directories by Id instead of by name. The root directory always uses the predefined Id 0x7FFFFFFFFFFFFFFF.

The Attributes parameter specifies the entry's attributes; please refer to Microsoft's File Attribute Constants article for attribute descriptions.

The Status parameter contains an NT status code that indicates the outcome of the operation; 0 indicates success. To convert this value to a Win32 error code, call the NtStatusToWin32Error method.

Note: This event will not fire for failed requests unless the ProcessFailedRequests property is enabled. Applications may change this parameter's value if they want a different NT status code to be returned.

The DirectoryContext, HandleContext, and EnumerationContext parameters are placeholders for application-defined data associated with the directory, specific handle, and enumeration, respectively. (For general-purpose events, the DirectoryContext is called FileContext instead.) DirectoryContext corresponds to the FileContext in the file/directory creation, opening, and closing events. Please refer to the Contexts topic for more information.

The ProcessRequest parameter controls whether the directory entry should actually be reported to the requestor; it is true by default. Setting this parameter to false will "hide" the directory entry (i.e., prevent it from being reported).

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

AfterFilterAttachToVolume Event (CBFilter Component)

This event fires after the filter attaches to a newly mounted filesystem volume.

Syntax

public event OnAfterFilterAttachToVolumeHandler OnAfterFilterAttachToVolume;

public delegate void OnAfterFilterAttachToVolumeHandler(object sender, CbfilterAfterFilterAttachToVolumeEventArgs e);

public class CbfilterAfterFilterAttachToVolumeEventArgs : EventArgs {
  public string VolumeName { get; }
  public int ResultCode { get; set; }
}
Public Event OnAfterFilterAttachToVolume As OnAfterFilterAttachToVolumeHandler

Public Delegate Sub OnAfterFilterAttachToVolumeHandler(sender As Object, e As CbfilterAfterFilterAttachToVolumeEventArgs)

Public Class CbfilterAfterFilterAttachToVolumeEventArgs Inherits EventArgs
  Public ReadOnly Property VolumeName As String
  Public Property ResultCode As Integer
End Class

Remarks

This event fires after the filter attaches to the newly mounted filesystem volume specified by VolumeName. Please refer to the FireVolumeEvents property for more information.

Applications need to handle this event only if the FireVolumeEvents property includes the FS_MOUNT_CONTROL flag.

Note: This event won't fire for any volumes skipped during the BeforeFilterAttachToVolume event; please refer to its documentation for more information.

Applications can use this event to add volume-specific rules for the volume that has been mounted (keeping in mind that this event does not fire for volumes that are already present when StartFilter is called). Applications that intend to do so must ensure that proper thread synchronization techniques are used when manipulating or enumerating the rule lists, because this event's handler will always execute in the context of some worker thread.

Applications must be aware that this event fires as a direct response to a filesystem state change (mount or unmount). Various system components or third-party actors can perform supplementary filesystem mounting and unmounting during main unmount operations (e.g., Volume Service is one such component). This can cause seemingly excessive events to be fired, and sometimes they can be fired out of order (such as two *Attach or *Detach events fired in a row).

The format of the VolumeName parameter's value depends on whether the ResolveNtDeviceToDriveLetter configuration setting is enabled; please refer to its documentation for more information. Applications can obtain additional information about a volume by retrieving its GUID using the GetVolumeGUID method, and then using that GUID to call various Windows API functions.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

AfterFilterDetachFromVolume Event (CBFilter Component)

This event fires after the filter detaches from a filesystem volume.

Syntax

public event OnAfterFilterDetachFromVolumeHandler OnAfterFilterDetachFromVolume;

public delegate void OnAfterFilterDetachFromVolumeHandler(object sender, CbfilterAfterFilterDetachFromVolumeEventArgs e);

public class CbfilterAfterFilterDetachFromVolumeEventArgs : EventArgs {
  public string VolumeName { get; }
  public int ResultCode { get; set; }
}
Public Event OnAfterFilterDetachFromVolume As OnAfterFilterDetachFromVolumeHandler

Public Delegate Sub OnAfterFilterDetachFromVolumeHandler(sender As Object, e As CbfilterAfterFilterDetachFromVolumeEventArgs)

Public Class CbfilterAfterFilterDetachFromVolumeEventArgs Inherits EventArgs
  Public ReadOnly Property VolumeName As String
  Public Property ResultCode As Integer
End Class

Remarks

This event fires after the filter detaches from the filesystem volume specified by VolumeName, typically because of the volume being unmounted. Please refer to the FireVolumeEvents property for more information.

Applications need to handle this event only if the FireVolumeEvents property includes the FS_MOUNT_CONTROL flag.

Note: This event won't fire for any volumes skipped during the BeforeFilterAttachToVolume event; please refer to its documentation for more information.

Applications should use this event to remove volume-specific rules for the volume that has been unmounted. Applications that intend to do so must ensure that proper thread synchronization techniques are used when manipulating or enumerating the rule lists, because this event's handler will always execute in the context of some worker thread.

Applications must be aware that this event fires as a direct response to a filesystem state change (mount or unmount). Various system components or third-party actors can perform supplementary filesystem mounting and unmounting during main unmount operations (e.g., Volume Service is one such component). This can cause seemingly excessive events to be fired, and sometimes they can be fired out of order (such as two *Attach or *Detach events fired in a row).

The format of the VolumeName parameter's value depends on whether the ResolveNtDeviceToDriveLetter configuration setting is enabled; please refer to its documentation for more information. Applications can obtain additional information about a volume by retrieving its GUID using the GetVolumeGUID method, and then using that GUID to call various Windows API functions.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

AfterFsctl Event (CBFilter Component)

This event fires after an IRP_MJ_FILE_SYSTEM_CONTROL request is processed.

Syntax

public event OnAfterFsctlHandler OnAfterFsctl;

public delegate void OnAfterFsctlHandler(object sender, CbfilterAfterFsctlEventArgs e);

public class CbfilterAfterFsctlEventArgs : EventArgs {
  public string FileName { get; }
  public int FsControlCode { get; }
  public IntPtr InBuffer { get; }
  public int InBufferLength { get; }
  public int InBufferValidBytes { get; }
  public IntPtr OutBuffer { get; }
  public int OutBufferLength { get; }
  public int OutBufferValidBytes { get; set; }
  public int Status { get; set; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnAfterFsctl As OnAfterFsctlHandler

Public Delegate Sub OnAfterFsctlHandler(sender As Object, e As CbfilterAfterFsctlEventArgs)

Public Class CbfilterAfterFsctlEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public ReadOnly Property FsControlCode As Integer
  Public ReadOnly Property InBuffer As IntPtr
  Public ReadOnly Property InBufferLength As Integer
  Public ReadOnly Property InBufferValidBytes As Integer
  Public ReadOnly Property OutBuffer As IntPtr
  Public ReadOnly Property OutBufferLength As Integer
  Public Property OutBufferValidBytes As Integer
  Public Property Status As Integer
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ResultCode As Integer
End Class

Remarks

This event fires after an IRP_MJ_FILE_SYSTEM_CONTROL (FSCTL) request is processed. Such requests are sent using the Windows API's DeviceIoControl function (user mode), or ZwFsControlFile function (kernel mode); please refer to Microsoft's documentation for more information.

Applications may use this event to modify the output data (if there are any) before the response is returned to the requestor. Applications that choose to do this must:

  1. copy no more than OutBufferLength bytes into OutBuffer; and
  2. update the OutBufferValidBytes parameter's value afterward so that it correctly reflects the amount of data in OutBuffer.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_AFTER_FSCTL flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The FileName parameter reflects the file, directory, or volume targeted by the request.

The FsControlCode parameter reflects the requested filesystem control code (FSCTL).

The InBuffer parameter points to a memory buffer that contains the data required to perform the operation. The InBufferLength and InBufferValidBytes parameters reflect the capacity of InBuffer and the length of the data it contains (respectively), in bytes; InBufferValidBytes may be less than InBufferLength (unless the request did not include data, in which case both will be 0).

The OutBuffer parameter points to a memory buffer that contains the data returned by the operation. The OutBufferLength and OutBufferValidBytes parameters reflect the capacity of OutBuffer and the length of the data it contains (respectively), in bytes; OutBufferValidBytes may be less than OutBufferLength (unless the operation did not return data, in which case both will be 0).

Please see the Buffer Parameters topic for more information on how to work with memory buffer event parameters.

The Status parameter contains an NT status code that indicates the outcome of the operation; 0 indicates success. To convert this value to a Win32 error code, call the NtStatusToWin32Error method.

Note: This event will not fire for failed requests unless the ProcessFailedRequests property is enabled. Applications may change this parameter's value if they want a different NT status code to be returned.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

AfterGetFileSecurity Event (CBFilter Component)

This event fires after a file or directory's security attributes are retrieved.

Syntax

public event OnAfterGetFileSecurityHandler OnAfterGetFileSecurity;

public delegate void OnAfterGetFileSecurityHandler(object sender, CbfilterAfterGetFileSecurityEventArgs e);

public class CbfilterAfterGetFileSecurityEventArgs : EventArgs {
  public string FileName { get; }
  public int SecurityInformation { get; }
  public IntPtr SecurityDescriptor { get; }
  public int Length { get; }
  public int LengthNeeded { get; set; }
  public int Status { get; set; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnAfterGetFileSecurity As OnAfterGetFileSecurityHandler

Public Delegate Sub OnAfterGetFileSecurityHandler(sender As Object, e As CbfilterAfterGetFileSecurityEventArgs)

Public Class CbfilterAfterGetFileSecurityEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public ReadOnly Property SecurityInformation As Integer
  Public ReadOnly Property SecurityDescriptor As IntPtr
  Public ReadOnly Property Length As Integer
  Public Property LengthNeeded As Integer
  Public Property Status As Integer
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ResultCode As Integer
End Class

Remarks

This event fires after security attributes are retrieved for the file or directory specified by FileName.

Note: This event will not fire every time a file or directory is accessed. To check file security upon each access to a file or directory, implement the file create and open events and perform the necessary checks there instead.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_AFTER_GET_SECURITY flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The SecurityInformation parameter indicates which pieces of security information were requested. Please refer to Microsoft's SECURITY_INFORMATION data-type documentation for more information about possible values.

The SecurityDescriptor parameter points to a memory buffer that, if the request was successful, contains the requested security information. The Length parameter reflects the length of this data, in bytes. Please see the Buffer Parameters topic for more information on how to work with memory buffer event parameters.

The data are formatted as a SECURITY_DESCRIPTOR structure in self-relative format; please refer to the Microsoft's documentation for more information.

Applications that wish to modify the security information may do so by replacing the data in the SecurityDescriptor buffer. If the current Length is too small to accommodate the new security information, set LengthNeeded to the number of bytes necessary to hold the data and return the ERROR_INSUFFICIENT_BUFFER error code via ResultCode.

The Status parameter contains an NT status code that indicates the outcome of the operation; 0 indicates success. To convert this value to a Win32 error code, call the NtStatusToWin32Error method.

Note: This event will not fire for failed requests unless the ProcessFailedRequests property is enabled. Applications may change this parameter's value if they want a different NT status code to be returned.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

AfterGetFileSizes Event (CBFilter Component)

This event fires after a file's size information is retrieved.

Syntax

public event OnAfterGetFileSizesHandler OnAfterGetFileSizes;

public delegate void OnAfterGetFileSizesHandler(object sender, CbfilterAfterGetFileSizesEventArgs e);

public class CbfilterAfterGetFileSizesEventArgs : EventArgs {
  public string FileName { get; }
  public long Size { get; set; }
  public long AllocationSize { get; set; }
  public int Status { get; set; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnAfterGetFileSizes As OnAfterGetFileSizesHandler

Public Delegate Sub OnAfterGetFileSizesHandler(sender As Object, e As CbfilterAfterGetFileSizesEventArgs)

Public Class CbfilterAfterGetFileSizesEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public Property Size As Long
  Public Property AllocationSize As Long
  Public Property Status As Integer
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ResultCode As Integer
End Class

Remarks

This event fires after size information is retrieved for the file specified by FileName.

Applications that intend to modify a file's contents should use this event to modify the file's actual size or allocation size as necessary. Applications that make use of virtual files should use this event to report the size of the virtual files.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_AFTER_GET_SIZES flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The Size parameter specifies the actual size of the file, in bytes.

The AllocationSize parameter specifies the amount of space allocated for the file, in bytes.

The Status parameter contains an NT status code that indicates the outcome of the operation; 0 indicates success. To convert this value to a Win32 error code, call the NtStatusToWin32Error method.

Note: This event will not fire for failed requests unless the ProcessFailedRequests property is enabled. Applications may change this parameter's value if they want a different NT status code to be returned.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

AfterGetReparsePoint Event (CBFilter Component)

This event fires after a file or directory's reparse point information is retrieved.

Syntax

public event OnAfterGetReparsePointHandler OnAfterGetReparsePoint;

public delegate void OnAfterGetReparsePointHandler(object sender, CbfilterAfterGetReparsePointEventArgs e);

public class CbfilterAfterGetReparsePointEventArgs : EventArgs {
  public string FileName { get; }
  public IntPtr ReparseBuffer { get; }
  public int BufferLength { get; }
  public int DataLength { get; set; }
  public int LengthNeeded { get; set; }
  public int Status { get; set; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnAfterGetReparsePoint As OnAfterGetReparsePointHandler

Public Delegate Sub OnAfterGetReparsePointHandler(sender As Object, e As CbfilterAfterGetReparsePointEventArgs)

Public Class CbfilterAfterGetReparsePointEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public ReadOnly Property ReparseBuffer As IntPtr
  Public ReadOnly Property BufferLength As Integer
  Public Property DataLength As Integer
  Public Property LengthNeeded As Integer
  Public Property Status As Integer
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ResultCode As Integer
End Class

Remarks

This event fires after reparse point information is retrieved for the file or directory specified by FileName.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_AFTER_GET_REPARSE_POINT flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The ReparseBuffer parameter points to a memory buffer that, if the request was successful, contains the requested reparse point information. The DataLength parameter reflects the length of this data, in bytes. Please see the Buffer Parameters topic for more information on how to work with memory buffer event parameters.

Please refer to the Reparse Points topic for more information.

Applications that wish to modify the reparse point information may do so by replacing the data in the ReparseBuffer buffer. If the current BufferLength is too small to accommodate the new information, the application should write as much data as possible, set LengthNeeded appropriately, and return the STATUS_BUFFER_OVERFLOW status code via Status.

The Status parameter contains an NT status code that indicates the outcome of the operation; 0 indicates success. To convert this value to a Win32 error code, call the NtStatusToWin32Error method.

Note: This event will not fire for failed requests unless the ProcessFailedRequests property is enabled. Applications may change this parameter's value if they want a different NT status code to be returned.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information.

Depending on how the request originator accessed the specified file or directory, it may or may not currently be open. The FileContext and HandleContext parameters will be absent if it is not open, in which case they will be IntPtr.Zero.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

AfterIoctl Event (CBFilter Component)

This event fires after an IRP_MJ_DEVICE_CONTROL request is processed.

Syntax

public event OnAfterIoctlHandler OnAfterIoctl;

public delegate void OnAfterIoctlHandler(object sender, CbfilterAfterIoctlEventArgs e);

public class CbfilterAfterIoctlEventArgs : EventArgs {
  public string FileName { get; }
  public int IoControlCode { get; }
  public IntPtr InBuffer { get; }
  public int InBufferLength { get; }
  public int InBufferValidBytes { get; }
  public IntPtr OutBuffer { get; }
  public int OutBufferLength { get; }
  public int OutBufferValidBytes { get; set; }
  public int Status { get; set; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnAfterIoctl As OnAfterIoctlHandler

Public Delegate Sub OnAfterIoctlHandler(sender As Object, e As CbfilterAfterIoctlEventArgs)

Public Class CbfilterAfterIoctlEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public ReadOnly Property IoControlCode As Integer
  Public ReadOnly Property InBuffer As IntPtr
  Public ReadOnly Property InBufferLength As Integer
  Public ReadOnly Property InBufferValidBytes As Integer
  Public ReadOnly Property OutBuffer As IntPtr
  Public ReadOnly Property OutBufferLength As Integer
  Public Property OutBufferValidBytes As Integer
  Public Property Status As Integer
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ResultCode As Integer
End Class

Remarks

This event fires after an IRP_MJ_DEVICE_CONTROL (IOCTL) request is processed. Such requests are sent using the Windows API's DeviceIoControl function (user mode), or ZwDeviceIoControlFile function (kernel mode). Please refer to Microsoft's documentation for more information.

Applications may use this event to modify the output data (if there are any) before the response is returned to the requestor. Applications that choose to do this must:

  1. copy no more than OutBufferLength bytes into OutBuffer; and
  2. update the OutBufferValidBytes parameter's value afterward so that it correctly reflects the amount of data in OutBuffer.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_AFTER_IOCTL flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The FileName parameter reflects the file, directory, or volume targeted by the request.

The IoControlCode parameter reflects the requested I/O control code (IOCTL).

The InBuffer parameter points to a memory buffer that contains the data required to perform the operation. The InBufferLength and InBufferValidBytes parameters reflect the capacity of InBuffer and the length of the data it contains (respectively), in bytes; InBufferValidBytes may be less than InBufferLength (unless the request did not include data, in which case both will be 0).

The OutBuffer parameter points to a memory buffer that contains the data returned by the operation. The OutBufferLength and OutBufferValidBytes parameters reflect the capacity of OutBuffer and the length of the data it contains (respectively), in bytes; OutBufferValidBytes may be less than OutBufferLength (unless the operation did not return data, in which case both will be 0).

Please see the Buffer Parameters topic for more information on how to work with memory buffer event parameters.

The Status parameter contains an NT status code that indicates the outcome of the operation; 0 indicates success. To convert this value to a Win32 error code, call the NtStatusToWin32Error method.

Note: This event will not fire for failed requests unless the ProcessFailedRequests property is enabled. Applications may change this parameter's value if they want a different NT status code to be returned.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

AfterLock Event (CBFilter Component)

This event fires after a range of bytes in a file is locked.

Syntax

public event OnAfterLockHandler OnAfterLock;

public delegate void OnAfterLockHandler(object sender, CbfilterAfterLockEventArgs e);

public class CbfilterAfterLockEventArgs : EventArgs {
  public string FileName { get; }
  public long Offset { get; }
  public long Length { get; }
  public long Key { get; }
  public bool FailImmediately { get; }
  public bool ExclusiveLock { get; }
  public int Status { get; set; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnAfterLock As OnAfterLockHandler

Public Delegate Sub OnAfterLockHandler(sender As Object, e As CbfilterAfterLockEventArgs)

Public Class CbfilterAfterLockEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public ReadOnly Property Offset As Long
  Public ReadOnly Property Length As Long
  Public ReadOnly Property Key As Long
  Public ReadOnly Property FailImmediately As Boolean
  Public ReadOnly Property ExclusiveLock As Boolean
  Public Property Status As Integer
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ResultCode As Integer
End Class

Remarks

This event fires after a range of bytes in the file specified by FileName is locked; This request is made either by the OS, or on behalf of a user mode application that called the Windows API's LockFile or LockFileEx function.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_AFTER_LOCK_CONTROL flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The Offset parameter reflects the byte offset where the byte range lock starts.

The Length parameter reflects the length of the byte range lock.

The Key parameter reflects the key that the byte range lock is associated with. This key is used to identify the byte range lock in later unlock-by-key requests.

The FailImmediately parameter indicates whether the request was to fail if the lock could not be granted immediately.

The ExclusiveLock parameter indicates whether the byte range lock was to be exclusive (true) or shared (false).

The Status parameter contains an NT status code that indicates the outcome of the operation; 0 indicates success. To convert this value to a Win32 error code, call the NtStatusToWin32Error method.

Note: This event will not fire for failed requests unless the ProcessFailedRequests property is enabled. Applications may change this parameter's value if they want a different NT status code to be returned.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

AfterOpenFile Event (CBFilter Component)

This event fires after a file or directory is opened.

Syntax

public event OnAfterOpenFileHandler OnAfterOpenFile;

public delegate void OnAfterOpenFileHandler(object sender, CbfilterAfterOpenFileEventArgs e);

public class CbfilterAfterOpenFileEventArgs : EventArgs {
  public string FileName { get; }
  public int ExistingAttributes { get; }
  public bool Isolate { get; }
  public string BackendFileName { get; }
  public int DesiredAccess { get; }
  public int Attributes { get; }
  public int ShareMode { get; }
  public int Options { get; }
  public int CreateDisposition { get; }
  public IntPtr SecurityDescriptor { get; }
  public int Length { get; }
  public int Status { get; set; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnAfterOpenFile As OnAfterOpenFileHandler

Public Delegate Sub OnAfterOpenFileHandler(sender As Object, e As CbfilterAfterOpenFileEventArgs)

Public Class CbfilterAfterOpenFileEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public ReadOnly Property ExistingAttributes As Integer
  Public ReadOnly Property Isolate As Boolean
  Public ReadOnly Property BackendFileName As String
  Public ReadOnly Property DesiredAccess As Integer
  Public ReadOnly Property Attributes As Integer
  Public ReadOnly Property ShareMode As Integer
  Public ReadOnly Property Options As Integer
  Public ReadOnly Property CreateDisposition As Integer
  Public ReadOnly Property SecurityDescriptor As IntPtr
  Public ReadOnly Property Length As Integer
  Public Property Status As Integer
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ResultCode As Integer
End Class

Remarks

This event fires after the file or directory specified by FileName is opened. Please refer to the File Create/Open Events topic for more information about how the component determines whether to fire this event or AfterCreateFile.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_AFTER_OPEN flag.

Note: Applications must have the FilterOwnRequests configuration setting enabled if they wish to filter their own file/directory open requests.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

When extended rules are used or the AlwaysRequestAttributesOnOpen configuration setting is enabled, the driver requests attributes of the entity from the filesystem and passes them to ExistingAttributes. If the attributes are not requested, this parameter contains 0.

Isolation-related functionality is under construction.

The DesiredAccess, Attributes, ShareMode, and CreateDisposition parameters reflect the values that were passed for the similarly named parameters of the Windows API's CreateFile function (or, more accurately, the values carried by the IRP_MJ_CREATE IRP).

DesiredAccess may contain one or more of the following access flags:

DESIRED_ACCESS_FILE_LIST_DIRECTORY0x00000001For a directory, the right to list the contents of the directory.

DESIRED_ACCESS_FILE_READ_DATA0x00000001For a file object, the right to read the corresponding file data.

For a directory object, the right to read the corresponding directory data.

DESIRED_ACCESS_FILE_ADD_FILE0x00000002For a directory, the right to create a file in the directory.

DESIRED_ACCESS_FILE_WRITE_DATA0x00000002For a file object, the right to write data to the file.

For a directory object, the right to create a file in the directory

DESIRED_ACCESS_FILE_ADD_SUBDIRECTORY0x00000004For a directory, the right to create a subdirectory.

DESIRED_ACCESS_FILE_APPEND_DATA0x00000004For a file object, the right to append data to the file.

(For local files, write operations will not overwrite existing data if this flag is specified without FILE_WRITE_DATA.) For a directory object, the right to create a subdirectory (FILE_ADD_SUBDIRECTORY).

DESIRED_ACCESS_FILE_READ_EA0x00000008The right to read extended file attributes.

DESIRED_ACCESS_FILE_WRITE_EA0x00000010The right to write extended file attributes.

DESIRED_ACCESS_FILE_EXECUTE0x00000020For a native code file, the right to execute the file.

This access right given to scripts may cause the script to be executable, depending on the script interpreter.

DESIRED_ACCESS_FILE_DELETE_CHILD0x00000040For a directory, the right to delete a directory and all the files it contains, including read-only files.

DESIRED_ACCESS_FILE_READ_ATTRIBUTES0x00000080The right to read file attributes.

DESIRED_ACCESS_FILE_WRITE_ATTRIBUTES0x00000100The right to write file attributes.

DESIRED_ACCESS_READ_CONTROL0x00020000The right to read the information in the file or directory object's security descriptor.

This does not include the information in the SACL.

DESIRED_ACCESS_STANDARD_RIGHTS_READ0x00020000Includes READ_CONTROL, which is the right to read the information in the file or directory object's security descriptor.

This does not include the information in the SACL.

DESIRED_ACCESS_STANDARD_RIGHTS_WRITE0x00020000Same as STANDARD_RIGHTS_READ

DESIRED_ACCESS_STANDARD_RIGHTS_EXECUTE0x00020000Same as STANDARD_RIGHTS_READ

DESIRED_ACCESS_SYNCHRONIZE0x00100000The right to use the object for synchronization.

This enables a thread to wait until the object is in the signaled state. Some object types do not support this access right.

DESIRED_ACCESS_FILE_ALL_ACCESS0x001F01FFAll possible access rights for a file.

DESIRED_ACCESS_FILE_GENERIC_READ0x00120089A combinarion of flags that allow reading of the file.

Note: Don't match received values against this flag. Instead, use flags that specify the rights that you want to verify or add/remove.

DESIRED_ACCESS_FILE_GENERIC_WRITE0x00120116A combinarion of flags that allow modifications to the file.

Note: Don't match received values against this flag. Instead, use flags that specify the rights that you want to verify or add/remove.

DESIRED_ACCESS_FILE_GENERIC_EXECUTE0x001200A0A combinarion of flags that allow execution of the file.

Note: Don't match received values against this flag. Instead, use flags that specify the rights that you want to verify or add/remove.

Attributes may contain one or more of the following attributes:

FILE_SYS_ATTR_READ_ONLY0x00000001The file is read-only.

Applications can read the file, but cannot write to it or delete it. This attribute is not honored on directories.

FILE_SYS_ATTR_HIDDEN0x00000002The file or directory is hidden.

The file is not included in an ordinary directory listing.

FILE_SYS_ATTR_SYSTEM0x00000004A file or directory that the operating system uses a part of, or uses exclusively.

FILE_SYS_ATTR_DIRECTORY0x00000010The entry is a directory.

FILE_SYS_ATTR_ARCHIVE0x00000020The entry is an archive file or directory.

Applications typically use this attribute to mark files for backup or removal.

FILE_SYS_ATTR_NORMAL0x00000080A file doesn't have other attributes set.

This attribute is valid only when used alone.

FILE_SYS_ATTR_TEMPORARY0x00000100A file that is being used for temporary storage.

File systems avoid writing data back to mass storage if sufficient cache memory is available, because typically, an application deletes a temporary file after the handle is closed. In that scenario, the system can entirely avoid writing the data. Otherwise, the data are written after the handle is closed.

FILE_SYS_ATTR_SPARSE_FILE0x00000200A file that is a sparse file.

FILE_SYS_ATTR_REPARSE_POINT0x00000400A file that is a reparse point or a symbolic link.

FILE_SYS_ATTR_COMPRESSED0x00000800A file or directory that is compressed.

For a file, all of the data in the file are compressed. For a directory, compression is the default for newly created files and subdirectories. A filesystem implementation can make use of this attribute by setting the SupportCompressedAttribute property to true and then properly handling the GetFileInfo, EnumerateDirectory, and SetFileAttributes events.

FILE_SYS_ATTR_OFFLINE0x00001000The data of a file are not available immediately.

This attribute indicates that the file data are physically moved to offline storage.

FILE_SYS_ATTR_NOT_CONTENT_INDEXED0x00002000The file or directory is not to be indexed by the content indexing service.

FILE_SYS_ATTR_ENCRYPTED0x00004000A file or directory that is encrypted.

For a file, all data streams in the file are encrypted. For a directory, encryption is the default for newly created files and subdirectories.

Note: This flag is used by NTFS and the OS sends undocumented requests to the filesystem based on this flag. The flag should not be used for files in custom filesystem implementations.

FILE_SYS_ATTR_VIRTUAL0x00010000Reserved.

Note: This flag is reserved by the OS and should not be used for files in custom filesystem implementations.

FILE_SYS_ATTR_RECALL_ON_OPEN0x00040000The file or directory has no physical representation on the local system; the item is virtual.

Opening the item will be more expensive than normal (e.g., it will cause at least some of it to be fetched from a remote store). This flag is reported by filesystems during directory enumerations.

ShareMode may contain zero or more of the following share mode flags:

FILESYS_SHARE_READ0x00000001Enables subsequent open operations on a file or device to request read access.

Enables subsequent open operations to request read access; otherwise, no process can open the file or device if it requests read access. If this flag is not specified, but the file or device has been opened for read access, the function fails.

FILESYS_SHARE_WRITE0x00000002Enables subsequent open operations on a file or device to request write access.

Enables subsequent open operations to request write access; otherwise, no process can open the file or device if it requests write access. If this flag is not specified, but the file or device has been opened for write access or has a file mapping with write access, the function fails.

FILESYS_SHARE_DELETE0x00000004Enables subsequent open operations on a file or device to request delete access.

Enables subsequent open operations to request delete access; otherwise, no process can open the file or device if it requests delete access. If this flag is not specified, but the file or device has been opened for delete access, the function fails.

Note: Delete access allows both delete and rename operations.

CreateDisposition may contain one of the following values:

FILE_DISPOSITION_CREATE_NEW0x00000001Creates a new file, only if it does not already exist.

If the specified file exists, the operation fails with an "already exists" error.

FILE_DISPOSITION_CREATE_ALWAYS0x00000002Creates a new file, always.

If the specified file exists and is writable, the system overwrites the file. If the specified file does not exist and is a valid path, a new file is created.

FILE_DISPOSITION_OPEN_EXISTING0x00000003Opens a file, only if it exists

If the specified file does not exist, opening fails.

FILE_DISPOSITION_OPEN_ALWAYS0x00000004Opens a file, always.

If the specified file exists, the operation succeeds. If the specified file does not exist and is a valid path to a writable location, the a file is created.

FILE_DISPOSITION_TRUNCATE_EXISTING0x00000005Opens a file and truncates it so that its size is zero bytes, only if it exists.

If the specified file does not exist, the operation fails with a "file not found" error.

Options contains the flags that are described in the CreateOptions parameter of the native API's ZwCreateFile function. Most of those flags correspond to flags passed in the FlagsAndAttributes parameter of the Windows API's CreateFile function, but some flags are specific to the native API. If you need those flags, check both functions' descriptions.

Please refer to Microsoft's documentation for detailed information about these constants.

To determine whether the request was for a file or a directory, compare Attributes against the FILE_SYS_ATTR_DIRECTORY constant, as follows: // Check whether the request is for a file or a directory. bool isDirectory = Attributes & FILE_SYS_ATTR_DIRECTORY == FILE_SYS_ATTR_DIRECTORY; FILE_SYS_ATTR_DIRECTORY will be present if it was specified by the calling process or if the existing filesystem entry is a directory.

To determine whether a file will be deleted when its last handle is closed, compare Options against the Windows API's FILE_FLAG_DELETE_ON_CLOSE constant, as follows: // Check whether the file will be deleted on close. bool deleteOnClose = Options & FILE_FLAG_DELETE_ON_CLOSE == FILE_FLAG_DELETE_ON_CLOSE; Note: Because files can be deleted in different ways, do not use this check to take actions related to tracking file deletion operations. Instead, use the events related to file deletion.

When a file or directory is created using the CreateFile() Windows API function, a caller can specify the security descriptor with the security information. This security information should be applied to a newly created file or directory. The component passes this security information in the SecurityInformation and SecurityDescriptor parameters, when the PassSecurityInFileOpenEvents configuration setting is enabled. If this configuration setting is omitted, the corresponding parameters are empty.

The SecurityInformation parameter reflects which pieces of security information, of those present in SecurityDescriptor, are valid and should have been applied. Please refer to Microsoft's SECURITY_INFORMATION data type documentation for more information about possible values.

The SecurityDescriptor parameter points to a memory buffer that contains the security information. The Length parameter reflects the length of this data, in bytes. Please see the Buffer Parameters topic for more information on how to work with memory buffer event parameters.

The data are formatted as a SECURITY_DESCRIPTOR structure in self-relative format; please refer to the Microsoft's documentation for more information.

If the Options contains the FILE_FLAG_DELETE_ON_CLOSE flag, the AfterCanFileBeDeleted event will fire after this event.

If the file is opened with extended attributes passed in the request, the AfterSetEa event will fire after this event.

The Status parameter contains an NT status code that indicates the outcome of the operation; 0 indicates success. To convert this value to a Win32 error code, call the NtStatusToWin32Error method.

Note: This event will not fire for failed requests unless the ProcessFailedRequests property is enabled. Applications may change this parameter's value if they want a different NT status code to be returned.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information.

When the ProcessFailedRequests property is enabled, this event may fire even if the specified file or directory has not been created or opened, in which case the Status parameter will be non-zero. When this occurs, applications must not alter the FileContext and HandleContext parameters.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

AfterQueryEa Event (CBFilter Component)

This event fires after information about extended attributes of a file is retrieved.

Syntax

public event OnAfterQueryEaHandler OnAfterQueryEa;

public delegate void OnAfterQueryEaHandler(object sender, CbfilterAfterQueryEaEventArgs e);

public class CbfilterAfterQueryEaEventArgs : EventArgs {
  public string FileName { get; }
  public IntPtr Buffer { get; }
  public int BufferLength { get; }
  public bool ReturnSingleEntry { get; }
  public IntPtr EaList { get; }
  public int EaListLength { get; }
  public int EaIndex { get; }
  public bool RestartScan { get; }
  public int LengthReturned { get; set; }
  public int Status { get; set; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnAfterQueryEa As OnAfterQueryEaHandler

Public Delegate Sub OnAfterQueryEaHandler(sender As Object, e As CbfilterAfterQueryEaEventArgs)

Public Class CbfilterAfterQueryEaEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public ReadOnly Property Buffer As IntPtr
  Public ReadOnly Property BufferLength As Integer
  Public ReadOnly Property ReturnSingleEntry As Boolean
  Public ReadOnly Property EaList As IntPtr
  Public ReadOnly Property EaListLength As Integer
  Public ReadOnly Property EaIndex As Integer
  Public ReadOnly Property RestartScan As Boolean
  Public Property LengthReturned As Integer
  Public Property Status As Integer
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ResultCode As Integer
End Class

Remarks

This event fires after information about extended attributes of the file specified by FileName is retrieved using the FltQueryEaFile function of the system API.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_AFTER_QUERY_EA flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The Buffer parameter points to a memory buffer that, if the request was successful, contains the requested information. The data in the buffer are formatted as a FILE_FULL_EA_INFORMATION structure; please refer to the Microsoft's documentation for more information. The Length parameter reflects the length of this buffer, in bytes. Please see the Buffer Parameters topic for more information on how to work with memory buffer event parameters.

ReturnSingleEntry specifies that the filesystem had to return only the first entry it has found.

EaList is an optional parameter that points to a caller-supplied memory buffer specifying the extended attributes to be queried. The data in the buffer are formatted as a FILE_GET_EA_INFORMATION structure; please refer to the Microsoft's documentation for more information. The EaListLength parameter reflects the length of this data, in bytes. If the caller of the FltQueryEaFile function did not specify any value, it will contain 0.

EaIndex is an optional parameter that specifies the starting index of the attribute, information about which was requested. This parameter is ignored by the filesystem if EaList points to a nonempty list. If the caller of the FltQueryEaFile function did not specify any value, the parameter will contain -1.

The RestartScan parameter instructs the filesystem to restart enumeration of extended attributes from the first entry. If the parameter is false, retrieval of the extended attributes is resumed by the filesystem after a previous request.

LengthReturned is an optional parameter that contains the size, in bytes, of the information, returned in the Buffer.

A handler may modify the contents of the Buffer given that the size of the modified data does not exceed the length of the buffer. When modifying the data, a handler should update LengthReturned accordingly.

The Status parameter contains an NT status code that indicates the outcome of the operation; 0 indicates success. To convert this value to a Win32 error code, call the NtStatusToWin32Error method.

Note: This event will not fire for failed requests unless the ProcessFailedRequests property is enabled. Applications may change this parameter's value if they want a different NT status code to be returned.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

AfterQueryFileInfo Event (CBFilter Component)

This event fires after information about a file or directory is retrieved.

Syntax

public event OnAfterQueryFileInfoHandler OnAfterQueryFileInfo;

public delegate void OnAfterQueryFileInfoHandler(object sender, CbfilterAfterQueryFileInfoEventArgs e);

public class CbfilterAfterQueryFileInfoEventArgs : EventArgs {
  public string FileName { get; }
  public int FileInformationClass { get; }
  public IntPtr Buffer { get; }
  public int BufferLength { get; }
  public int ValidBytes { get; set; }
  public int Status { get; set; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnAfterQueryFileInfo As OnAfterQueryFileInfoHandler

Public Delegate Sub OnAfterQueryFileInfoHandler(sender As Object, e As CbfilterAfterQueryFileInfoEventArgs)

Public Class CbfilterAfterQueryFileInfoEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public ReadOnly Property FileInformationClass As Integer
  Public ReadOnly Property Buffer As IntPtr
  Public ReadOnly Property BufferLength As Integer
  Public Property ValidBytes As Integer
  Public Property Status As Integer
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ResultCode As Integer
End Class

Remarks

This event fires after information about the file or directory specified by FileName is retrieved; This event typically fires in response to the Windows API's NtQueryInformationFile function.

Applications may use this event to modify the output data before the response is returned to the requestor. Applications that choose to do this must:

  1. copy no more than BufferLength bytes into Buffer; and
  2. update the ValidBytes parameter's value afterward so that it correctly reflects the amount of data in Buffer.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_AFTER_QUERY_FILE_INFO flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The FileInformationClass parameter indicates what kind of file information was requested. Please refer to the NtQueryInformationFile function's documentation for more information about possible values.

The Buffer parameter points to a memory buffer that, if the request was successful, contains the requested file information. The BufferLength and ValidBytes parameters reflect the capacity of Buffer and the length of the data it contains (respectively), in bytes; ValidBytes may be less than BufferLength. Please see the Buffer Parameters topic for more information on how to work with memory buffer event parameters.

The format of the data is determined by the specified FileInformationClass; please refer to the NtQueryInformationFile function's documentation for more information.

The Status parameter contains an NT status code that indicates the outcome of the operation; 0 indicates success. To convert this value to a Win32 error code, call the NtStatusToWin32Error method.

Note: This event will not fire for failed requests unless the ProcessFailedRequests property is enabled. Applications may change this parameter's value if they want a different NT status code to be returned.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

AfterReadFile Event (CBFilter Component)

This event fires after data are read from a file.

Syntax

public event OnAfterReadFileHandler OnAfterReadFile;

public delegate void OnAfterReadFileHandler(object sender, CbfilterAfterReadFileEventArgs e);

public class CbfilterAfterReadFileEventArgs : EventArgs {
  public string FileName { get; }
  public long Position { get; }
  public IntPtr Buffer { get; }
  public int BufferLength { get; }
  public int BytesToRead { get; }
  public int Reserved { get; }
  public int Direction { get; }
  public int BytesRead { get; set; }
  public int Status { get; set; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnAfterReadFile As OnAfterReadFileHandler

Public Delegate Sub OnAfterReadFileHandler(sender As Object, e As CbfilterAfterReadFileEventArgs)

Public Class CbfilterAfterReadFileEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public ReadOnly Property Position As Long
  Public ReadOnly Property Buffer As IntPtr
  Public ReadOnly Property BufferLength As Integer
  Public ReadOnly Property BytesToRead As Integer
  Public ReadOnly Property Reserved As Integer
  Public ReadOnly Property Direction As Integer
  Public Property BytesRead As Integer
  Public Property Status As Integer
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ResultCode As Integer
End Class

Remarks

This event fires after data are read from the file specified by FileName.

Applications may use this event to modify the data that were read from the file before it is returned to the requestor. Applications that choose to do this must:

  1. enable the ModifiableReadWriteBuffers configuration setting (i.e., before this event fires);
  2. copy no more than BytesToRead bytes into Buffer; and
  3. update the BytesRead parameter's value afterward so that it correctly reflects the amount of data in Buffer.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_AFTER_READ flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The Position parameter reflects the byte offset in the file at which reading started.

The Buffer parameter points to a memory buffer that, if the request was successful, contains the data that were read from the file. The BufferLength parameter reflects the capacity of Buffer, in bytes. Please see the Buffer Parameters topic for more information on how to work with memory buffer event parameters.

The BytesToRead parameter reflects how many bytes were to be read from the file (i.e., how many bytes the requestor expects will be read).

The Direction parameter indicates the request direction; please refer to the Cached and Non-Cached Requests topic for more information. Possible values are as follows:

FS_REQUEST_DIR_USER_NONCACHED0Operations performed in the user mode application <--> filesystem direction.
FS_REQUEST_DIR_USER_CACHED1Operations performed in the user mode application <--> system cache direction.
FS_REQUEST_DIR_SYSTEM_NONCACHED2Operations performed in the system cache <--> filesystem direction.
FS_REQUEST_DIR_SYSTEM_CACHED3Operations performed in the system component <--> system cache direction.

The BytesRead parameter specifies how many bytes were actually read from the file, and thus the length of the data in Buffer. This parameter's value must not exceed BufferLength (and should not exceed BytesToRead; please refer to BeforeReadFile for more information).

The Status parameter contains an NT status code that indicates the outcome of the operation; 0 indicates success. To convert this value to a Win32 error code, call the NtStatusToWin32Error method.

Note: This event will not fire for failed requests unless the ProcessFailedRequests property is enabled. Applications may change this parameter's value if they want a different NT status code to be returned.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information. (If the system's cache manager or memory manager initiated the operation, HandleContext may be absent, in which case it will be IntPtr.Zero.)

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

AfterRenameOrMoveFile Event (CBFilter Component)

This event fires after a file or directory is renamed or moved.

Syntax

public event OnAfterRenameOrMoveFileHandler OnAfterRenameOrMoveFile;

public delegate void OnAfterRenameOrMoveFileHandler(object sender, CbfilterAfterRenameOrMoveFileEventArgs e);

public class CbfilterAfterRenameOrMoveFileEventArgs : EventArgs {
  public string FileName { get; }
  public string NewFileName { get; }
  public int Status { get; set; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnAfterRenameOrMoveFile As OnAfterRenameOrMoveFileHandler

Public Delegate Sub OnAfterRenameOrMoveFileHandler(sender As Object, e As CbfilterAfterRenameOrMoveFileEventArgs)

Public Class CbfilterAfterRenameOrMoveFileEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public ReadOnly Property NewFileName As String
  Public Property Status As Integer
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ResultCode As Integer
End Class

Remarks

This event fires after the file or directory specified by FileName is renamed or moved to NewFileName.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_AFTER_RENAME flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

A rule's mask is matched against both previous and new filenames, and the event will fire when either of the names matches the mask.

The Status parameter contains an NT status code that indicates the outcome of the operation; 0 indicates success. To convert this value to a Win32 error code, call the NtStatusToWin32Error method.

Note: This event will not fire for failed requests unless the ProcessFailedRequests property is enabled. Applications may change this parameter's value if they want a different NT status code to be returned.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

AfterSetAllocationSize Event (CBFilter Component)

This event fires after a file's allocation size is changed.

Syntax

public event OnAfterSetAllocationSizeHandler OnAfterSetAllocationSize;

public delegate void OnAfterSetAllocationSizeHandler(object sender, CbfilterAfterSetAllocationSizeEventArgs e);

public class CbfilterAfterSetAllocationSizeEventArgs : EventArgs {
  public string FileName { get; }
  public long AllocationSize { get; }
  public int Status { get; set; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnAfterSetAllocationSize As OnAfterSetAllocationSizeHandler

Public Delegate Sub OnAfterSetAllocationSizeHandler(sender As Object, e As CbfilterAfterSetAllocationSizeEventArgs)

Public Class CbfilterAfterSetAllocationSizeEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public ReadOnly Property AllocationSize As Long
  Public Property Status As Integer
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ResultCode As Integer
End Class

Remarks

This event fires after the allocation size of the file specified by FileName is changed.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_AFTER_SET_SIZES flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The AllocationSize parameter reflects the new allocation size, in bytes. A file's allocation size is typically larger than its actual size because filesystem operations often reserve space on disk before writing additional data to a file.

The Status parameter contains an NT status code that indicates the outcome of the operation; 0 indicates success. To convert this value to a Win32 error code, call the NtStatusToWin32Error method.

Note: This event will not fire for failed requests unless the ProcessFailedRequests property is enabled. Applications may change this parameter's value if they want a different NT status code to be returned.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information. (If the system's cache manager or memory manager initiated the operation, HandleContext may be absent, in which case it will be IntPtr.Zero.)

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

AfterSetEa Event (CBFilter Component)

This event fires after extended attributes of a file are changed.

Syntax

public event OnAfterSetEaHandler OnAfterSetEa;

public delegate void OnAfterSetEaHandler(object sender, CbfilterAfterSetEaEventArgs e);

public class CbfilterAfterSetEaEventArgs : EventArgs {
  public string FileName { get; }
  public IntPtr Buffer { get; }
  public int BufferLength { get; }
  public int Status { get; set; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnAfterSetEa As OnAfterSetEaHandler

Public Delegate Sub OnAfterSetEaHandler(sender As Object, e As CbfilterAfterSetEaEventArgs)

Public Class CbfilterAfterSetEaEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public ReadOnly Property Buffer As IntPtr
  Public ReadOnly Property BufferLength As Integer
  Public Property Status As Integer
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ResultCode As Integer
End Class

Remarks

This event fires after extended attributes are changed for the file specified by FileName.

If the file is created or opened with extended attributes passed in the request, this event will fire shortly after the AfterCreateFile or AfterOpenFile event.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_AFTER_SET_EA flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The Buffer parameter points to a memory buffer that specifies the extended attribute information. The Length parameter reflects the length of this buffer, in bytes. Please see the Buffer Parameters topic for more information on how to work with memory buffer event parameters.

The data are formatted as a FILE_FULL_EA_INFORMATION structure; please refer to the Microsoft's documentation for more information.

The Status parameter contains an NT status code that indicates the outcome of the operation; 0 indicates success. To convert this value to a Win32 error code, call the NtStatusToWin32Error method.

Note: This event will not fire for failed requests unless the ProcessFailedRequests property is enabled. Applications may change this parameter's value if they want a different NT status code to be returned.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

AfterSetFileAttributes Event (CBFilter Component)

This event fires after a file or directory's attributes or times are changed.

Syntax

public event OnAfterSetFileAttributesHandler OnAfterSetFileAttributes;

public delegate void OnAfterSetFileAttributesHandler(object sender, CbfilterAfterSetFileAttributesEventArgs e);

public class CbfilterAfterSetFileAttributesEventArgs : EventArgs {
  public string FileName { get; }
  public DateTime CreationTime { get; }
  public DateTime LastAccessTime { get; }
  public DateTime LastWriteTime { get; }
  public DateTime ChangeTime { get; }
  public int Attributes { get; }
  public int Status { get; set; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnAfterSetFileAttributes As OnAfterSetFileAttributesHandler

Public Delegate Sub OnAfterSetFileAttributesHandler(sender As Object, e As CbfilterAfterSetFileAttributesEventArgs)

Public Class CbfilterAfterSetFileAttributesEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public ReadOnly Property CreationTime As DateTime
  Public ReadOnly Property LastAccessTime As DateTime
  Public ReadOnly Property LastWriteTime As DateTime
  Public ReadOnly Property ChangeTime As DateTime
  Public ReadOnly Property Attributes As Integer
  Public Property Status As Integer
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ResultCode As Integer
End Class

Remarks

This event fires after the attributes or times of the file or directory specified by FileName are changed.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_AFTER_SET_ATTRIBUTES flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The CreationTime, LastAccessTime, LastWriteTime, and ChangeTime parameters reflect the new time values, specified in UTC. A value of January 1, 1601 00:00:00 UTC indicates that the corresponding time value was not included in the request.

The Attributes parameter reflects the new attributes; please refer to Microsoft's File Attribute Constants article for attribute descriptions.

The Status parameter contains an NT status code that indicates the outcome of the operation; 0 indicates success. To convert this value to a Win32 error code, call the NtStatusToWin32Error method.

Note: This event will not fire for failed requests unless the ProcessFailedRequests property is enabled. Applications may change this parameter's value if they want a different NT status code to be returned.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

AfterSetFileInfo Event (CBFilter Component)

This event fires after information about a file or directory is changed.

Syntax

public event OnAfterSetFileInfoHandler OnAfterSetFileInfo;

public delegate void OnAfterSetFileInfoHandler(object sender, CbfilterAfterSetFileInfoEventArgs e);

public class CbfilterAfterSetFileInfoEventArgs : EventArgs {
  public string FileName { get; }
  public int FileInformationClass { get; }
  public IntPtr Buffer { get; }
  public int BufferLength { get; }
  public int ValidBytes { get; }
  public int Status { get; set; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnAfterSetFileInfo As OnAfterSetFileInfoHandler

Public Delegate Sub OnAfterSetFileInfoHandler(sender As Object, e As CbfilterAfterSetFileInfoEventArgs)

Public Class CbfilterAfterSetFileInfoEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public ReadOnly Property FileInformationClass As Integer
  Public ReadOnly Property Buffer As IntPtr
  Public ReadOnly Property BufferLength As Integer
  Public ReadOnly Property ValidBytes As Integer
  Public Property Status As Integer
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ResultCode As Integer
End Class

Remarks

This event fires after information about the file or directory specified by FileName is changed; This event typically fires in response to the Windows API's NtSetInformationFile function.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_AFTER_SET_FILE_INFO flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The FileInformationClass parameter indicates what kind of file information was set. Please refer to the NtSetInformationFile function's documentation for more information about possible values.

The Buffer parameter points to a memory buffer that, if the request was successful, contains the new file information. The BufferLength and ValidBytes parameters reflect the capacity of Buffer and the length of the data it contains (respectively), in bytes; ValidBytes may be less than BufferLength. Please see the Buffer Parameters topic for more information on how to work with memory buffer event parameters.

The format of the data is determined by the specified FileInformationClass; please refer to the NtSetInformationFile function's documentation for more information.

The Status parameter contains an NT status code that indicates the outcome of the operation; 0 indicates success. To convert this value to a Win32 error code, call the NtStatusToWin32Error method.

Note: This event will not fire for failed requests unless the ProcessFailedRequests property is enabled. Applications may change this parameter's value if they want a different NT status code to be returned.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

AfterSetFileSecurity Event (CBFilter Component)

This event fires after a file or directory's security attributes are changed.

Syntax

public event OnAfterSetFileSecurityHandler OnAfterSetFileSecurity;

public delegate void OnAfterSetFileSecurityHandler(object sender, CbfilterAfterSetFileSecurityEventArgs e);

public class CbfilterAfterSetFileSecurityEventArgs : EventArgs {
  public string FileName { get; }
  public int SecurityInformation { get; }
  public IntPtr SecurityDescriptor { get; }
  public int Length { get; }
  public int Status { get; set; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnAfterSetFileSecurity As OnAfterSetFileSecurityHandler

Public Delegate Sub OnAfterSetFileSecurityHandler(sender As Object, e As CbfilterAfterSetFileSecurityEventArgs)

Public Class CbfilterAfterSetFileSecurityEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public ReadOnly Property SecurityInformation As Integer
  Public ReadOnly Property SecurityDescriptor As IntPtr
  Public ReadOnly Property Length As Integer
  Public Property Status As Integer
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ResultCode As Integer
End Class

Remarks

This event fires after security attributes are changed for the file or directory specified by FileName.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_AFTER_SET_SECURITY flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The SecurityInformation parameter reflects which pieces of security information, of those present in SecurityDescriptor, were to be set. Please refer to Microsoft's SECURITY_INFORMATION data-type documentation for more information about possible values.

The SecurityDescriptor parameter points to a memory buffer that contains the new security information. The Length parameter reflects the length of this data, in bytes. Please see the Buffer Parameters topic for more information on how to work with memory buffer event parameters.

The data are formatted as a SECURITY_DESCRIPTOR structure in self-relative format; please refer to the Microsoft's documentation for more information.

The Status parameter contains an NT status code that indicates the outcome of the operation; 0 indicates success. To convert this value to a Win32 error code, call the NtStatusToWin32Error method.

Note: This event will not fire for failed requests unless the ProcessFailedRequests property is enabled. Applications may change this parameter's value if they want a different NT status code to be returned.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

AfterSetFileSize Event (CBFilter Component)

This event fires after a file is resized.

Syntax

public event OnAfterSetFileSizeHandler OnAfterSetFileSize;

public delegate void OnAfterSetFileSizeHandler(object sender, CbfilterAfterSetFileSizeEventArgs e);

public class CbfilterAfterSetFileSizeEventArgs : EventArgs {
  public string FileName { get; }
  public long Size { get; }
  public int Status { get; set; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnAfterSetFileSize As OnAfterSetFileSizeHandler

Public Delegate Sub OnAfterSetFileSizeHandler(sender As Object, e As CbfilterAfterSetFileSizeEventArgs)

Public Class CbfilterAfterSetFileSizeEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public ReadOnly Property Size As Long
  Public Property Status As Integer
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ResultCode As Integer
End Class

Remarks

This event fires after the file specified by FileName is resized, whether explicitly (e.g., truncation) or implicitly (i.e., as data are appended).

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_AFTER_SET_SIZES flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The Size parameter reflects the new file size, in bytes.

The Status parameter contains an NT status code that indicates the outcome of the operation; 0 indicates success. To convert this value to a Win32 error code, call the NtStatusToWin32Error method.

Note: This event will not fire for failed requests unless the ProcessFailedRequests property is enabled. Applications may change this parameter's value if they want a different NT status code to be returned.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information. (If the system's cache manager or memory manager initiated the operation, HandleContext may be absent, in which case it will be IntPtr.Zero.)

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

AfterSetReparsePoint Event (CBFilter Component)

This event fires after the OS creates or updates a reparse point on a file or directory.

Syntax

public event OnAfterSetReparsePointHandler OnAfterSetReparsePoint;

public delegate void OnAfterSetReparsePointHandler(object sender, CbfilterAfterSetReparsePointEventArgs e);

public class CbfilterAfterSetReparsePointEventArgs : EventArgs {
  public string FileName { get; }
  public long ReparseTag { get; }
  public IntPtr ReparseBuffer { get; }
  public int BufferLength { get; }
  public int DataLength { get; }
  public int Status { get; set; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnAfterSetReparsePoint As OnAfterSetReparsePointHandler

Public Delegate Sub OnAfterSetReparsePointHandler(sender As Object, e As CbfilterAfterSetReparsePointEventArgs)

Public Class CbfilterAfterSetReparsePointEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public ReadOnly Property ReparseTag As Long
  Public ReadOnly Property ReparseBuffer As IntPtr
  Public ReadOnly Property BufferLength As Integer
  Public ReadOnly Property DataLength As Integer
  Public Property Status As Integer
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ResultCode As Integer
End Class

Remarks

This event fires after the OS creates or updates a reparse point on a file or directory specified by FileName.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_AFTER_SET_REPARSE_POINT flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The ReparseTag parameter contains the reparse tag, which is the value the system uses to identify the format of the reparse point data. This value is also present in the ReparseBuffer data; the component extracts it and provides it separately for convenience.

The ReparseBuffer parameter points to a memory buffer that specifies the new reparse point information. The DataLength parameter reflects the length of the data contained in the buffer, in bytes. Please see the Buffer Parameters topic for more information on how to work with memory buffer event parameters.

Please refer to the Reparse Points topic for more information.

The Status parameter contains an NT status code that indicates the outcome of the operation; 0 indicates success. To convert this value to a Win32 error code, call the NtStatusToWin32Error method.

Note: This event will not fire for failed requests unless the ProcessFailedRequests property is enabled. Applications may change this parameter's value if they want a different NT status code to be returned.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

AfterUnlockAll Event (CBFilter Component)

This event fires after all locked byte ranges in a file are unlocked.

Syntax

public event OnAfterUnlockAllHandler OnAfterUnlockAll;

public delegate void OnAfterUnlockAllHandler(object sender, CbfilterAfterUnlockAllEventArgs e);

public class CbfilterAfterUnlockAllEventArgs : EventArgs {
  public string FileName { get; }
  public int Status { get; set; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnAfterUnlockAll As OnAfterUnlockAllHandler

Public Delegate Sub OnAfterUnlockAllHandler(sender As Object, e As CbfilterAfterUnlockAllEventArgs)

Public Class CbfilterAfterUnlockAllEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public Property Status As Integer
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ResultCode As Integer
End Class

Remarks

This event fires after all locked byte ranges in the file specified by FileName are unlocked.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_AFTER_LOCK_CONTROL flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The Status parameter contains an NT status code that indicates the outcome of the operation; 0 indicates success. To convert this value to a Win32 error code, call the NtStatusToWin32Error method.

Note: This event will not fire for failed requests unless the ProcessFailedRequests property is enabled. Applications may change this parameter's value if they want a different NT status code to be returned.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

AfterUnlockAllByKey Event (CBFilter Component)

This event fires after all locked byte ranges in a file, associated with a particular key, are unlocked.

Syntax

public event OnAfterUnlockAllByKeyHandler OnAfterUnlockAllByKey;

public delegate void OnAfterUnlockAllByKeyHandler(object sender, CbfilterAfterUnlockAllByKeyEventArgs e);

public class CbfilterAfterUnlockAllByKeyEventArgs : EventArgs {
  public string FileName { get; }
  public long Key { get; }
  public int Status { get; set; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnAfterUnlockAllByKey As OnAfterUnlockAllByKeyHandler

Public Delegate Sub OnAfterUnlockAllByKeyHandler(sender As Object, e As CbfilterAfterUnlockAllByKeyEventArgs)

Public Class CbfilterAfterUnlockAllByKeyEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public ReadOnly Property Key As Long
  Public Property Status As Integer
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ResultCode As Integer
End Class

Remarks

This event fires after all locked byte ranges in the file specified by FileName, and associated with the specified Key, are unlocked.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_AFTER_LOCK_CONTROL flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The Key parameter contains the key value specified when the byte ranges were locked. Please refer to the AfterLock event's documentation for more information.

The Status parameter contains an NT status code that indicates the outcome of the operation; 0 indicates success. To convert this value to a Win32 error code, call the NtStatusToWin32Error method.

Note: This event will not fire for failed requests unless the ProcessFailedRequests property is enabled. Applications may change this parameter's value if they want a different NT status code to be returned.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

AfterUnlockSingle Event (CBFilter Component)

This event fires after a particular locked byte range in a file is unlocked.

Syntax

public event OnAfterUnlockSingleHandler OnAfterUnlockSingle;

public delegate void OnAfterUnlockSingleHandler(object sender, CbfilterAfterUnlockSingleEventArgs e);

public class CbfilterAfterUnlockSingleEventArgs : EventArgs {
  public string FileName { get; }
  public long Offset { get; }
  public long Length { get; }
  public long Key { get; }
  public int Status { get; set; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnAfterUnlockSingle As OnAfterUnlockSingleHandler

Public Delegate Sub OnAfterUnlockSingleHandler(sender As Object, e As CbfilterAfterUnlockSingleEventArgs)

Public Class CbfilterAfterUnlockSingleEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public ReadOnly Property Offset As Long
  Public ReadOnly Property Length As Long
  Public ReadOnly Property Key As Long
  Public Property Status As Integer
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ResultCode As Integer
End Class

Remarks

This event fires after a particular locked byte range in the file specified by FileName is unlocked.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_AFTER_LOCK_CONTROL flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The Offset, Length, and Key parameters contain the starting byte offset, length, and key values (respectively) specified when the byte range was locked. Please refer to the AfterLock event's documentation for more information.

The Status parameter contains an NT status code that indicates the outcome of the operation; 0 indicates success. To convert this value to a Win32 error code, call the NtStatusToWin32Error method.

Note: This event will not fire for failed requests unless the ProcessFailedRequests property is enabled. Applications may change this parameter's value if they want a different NT status code to be returned.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

AfterWriteFile Event (CBFilter Component)

This event fires after data are written to a file.

Syntax

public event OnAfterWriteFileHandler OnAfterWriteFile;

public delegate void OnAfterWriteFileHandler(object sender, CbfilterAfterWriteFileEventArgs e);

public class CbfilterAfterWriteFileEventArgs : EventArgs {
  public string FileName { get; }
  public long Position { get; }
  public IntPtr Buffer { get; }
  public int BufferLength { get; }
  public int BytesToWrite { get; }
  public int Direction { get; }
  public int BytesWritten { get; set; }
  public int Status { get; set; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnAfterWriteFile As OnAfterWriteFileHandler

Public Delegate Sub OnAfterWriteFileHandler(sender As Object, e As CbfilterAfterWriteFileEventArgs)

Public Class CbfilterAfterWriteFileEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public ReadOnly Property Position As Long
  Public ReadOnly Property Buffer As IntPtr
  Public ReadOnly Property BufferLength As Integer
  Public ReadOnly Property BytesToWrite As Integer
  Public ReadOnly Property Direction As Integer
  Public Property BytesWritten As Integer
  Public Property Status As Integer
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ResultCode As Integer
End Class

Remarks

This event fires after data are written to the file specified by FileName.

Applications may use this event to inspect the data that were written to the file, but must not attempt to alter said data. If, during BeforeWriteFile, an application causes less data than requested to be written to the file, it should use this event to set BytesWritten back to the expected value (i.e., BytesToWrite) to prevent the requestor from behaving unexpectedly.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_AFTER_WRITE flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The Position parameter reflects the byte offset in the file at which writing started. A value of -1 means "append to the end of the file".

The Buffer parameter points to a memory buffer that contains the data that, if the request was successful, were written to the file. The BufferLength parameter reflects the capacity of Buffer, in bytes. Please see the Buffer Parameters topic for more information on how to work with memory buffer event parameters.

The BytesToWrite parameter reflects how many bytes were to be written to the file (i.e., how many bytes the requestor expects will be written).

The Direction parameter indicates the request direction; please refer to the Cached and Non-Cached Requests topic for more information. Possible values are as follows:

FS_REQUEST_DIR_USER_NONCACHED0Operations performed in the user mode application <--> filesystem direction.
FS_REQUEST_DIR_USER_CACHED1Operations performed in the user mode application <--> system cache direction.
FS_REQUEST_DIR_SYSTEM_NONCACHED2Operations performed in the system cache <--> filesystem direction.
FS_REQUEST_DIR_SYSTEM_CACHED3Operations performed in the system component <--> system cache direction.

The BytesWritten parameter specifies how many bytes were actually written to the file. This parameter's value must not exceed BufferLength (and should not exceed BytesToWrite; please refer to BeforeWriteFile for more information).

The Status parameter contains an NT status code that indicates the outcome of the operation; 0 indicates success. To convert this value to a Win32 error code, call the NtStatusToWin32Error method.

Note: This event will not fire for failed requests unless the ProcessFailedRequests property is enabled. Applications may change this parameter's value if they want a different NT status code to be returned.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information. (If the system's cache manager or memory manager initiated the operation, HandleContext may be absent, in which case it will be IntPtr.Zero.)

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

BeforeCanFileBeDeleted Event (CBFilter Component)

This event fires before the OS attempts to mark a file or directory for deletion or remove such a mark.

Syntax

public event OnBeforeCanFileBeDeletedHandler OnBeforeCanFileBeDeleted;

public delegate void OnBeforeCanFileBeDeletedHandler(object sender, CbfilterBeforeCanFileBeDeletedEventArgs e);

public class CbfilterBeforeCanFileBeDeletedEventArgs : EventArgs {
  public string FileName { get; }
  public int RequestType { get; }
  public bool CanDelete { get; set; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public bool ProcessRequest { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnBeforeCanFileBeDeleted As OnBeforeCanFileBeDeletedHandler

Public Delegate Sub OnBeforeCanFileBeDeletedHandler(sender As Object, e As CbfilterBeforeCanFileBeDeletedEventArgs)

Public Class CbfilterBeforeCanFileBeDeletedEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public ReadOnly Property RequestType As Integer
  Public Property CanDelete As Boolean
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ProcessRequest As Boolean
  Public Property ResultCode As Integer
End Class

Remarks

This event fires before the OS marks the file or directory specified by FileName for deletion or removes such a mark.

Files and directories can be deleted in two ways: (1) a file or directory can be opened with the FILE_FLAG_DELETE_ON_CLOSE flag, or (2) some process may call Windows API's NtSetInformationFile function with FILE_DISPOSITION_INFORMATION or FILE_DISPOSITION_INFORMATION_EX structure as a parameter.

If the file or directory is created or opened with the FILE_FLAG_DELETE_ON_CLOSE flag, this event is fired shortly before the BeforeCreateFile or BeforeOpenFile event.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_BEFORE_CAN_DELETE flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The RequestType indicates which kind of system request resulted in firing this event. It can be one of the following:

DEL_REQ_OPEN_FLAG0x1The file or directory is opened with the FILE_FLAG_DELETE_ON_CLOSE flag

DEL_REQ_SET_DISPOSITION0x2The system has sent the IRP_MJ_SET_INFORMATION request with SetFileDisposition structure as a parameter.

This request usually is sent using the NtSetInformationFile() Windows native API function.

The CanDelete parameter specifies whether the file or directory will be deleted. This parameter can be true or false depending on which request the OS has sent. Applications may prevent deletion of the file or directory by setting CanDelete to false. Changing CanDelete from false to true may or may not have the effect on the file being deleted later, so such a change should be avoided.

Note: If the file is opened with FILE_FLAG_DELETE_ON_CLOSE flag set and the event handler permits file deletion, such flag cannot be removed later (even with the call to NtSetInformationFile() API function).

The ProcessRequest parameter controls whether the request is sent onward for further processing by subsequent filter drivers and the filesystem; it is true by default.

The effect of ProcessRequest depends on what operation caused the event to fire:

  • If the event fires during the file open operation where the FILE_FLAG_DELETE_ON_CLOSE flag is set,
    • setting CanDelete to false and ProcessRequest to true causes the FILE_FLAG_DELETE_ON_CLOSE flag to be removed and the file open request to be passed further to the filesystem; and
    • setting CanDelete to false and ProcessRequest to false causes the file open request to fail with ACCESS_DENIED error.
  • If the event fires in the context of the call to NtSetInformationFile Windows API function, setting CanDelete to false causes the DeleteFlag parameter to be set to false and the request to be passed further to the filesystem. This combination effectively resets the file deletion state, known to the filesystem, to the false ("do not delete") value. The value of ProcessRequest in this case does not matter as the new value must reach the filesystem.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information. (If the specified file or directory was not opened before the request, both contexts will be absent, in which case these parameters will be IntPtr.Zero.)

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

BeforeCleanupFile Event (CBFilter Component)

This event fires before a file or directory handle is closed.

Syntax

public event OnBeforeCleanupFileHandler OnBeforeCleanupFile;

public delegate void OnBeforeCleanupFileHandler(object sender, CbfilterBeforeCleanupFileEventArgs e);

public class CbfilterBeforeCleanupFileEventArgs : EventArgs {
  public string FileName { get; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnBeforeCleanupFile As OnBeforeCleanupFileHandler

Public Delegate Sub OnBeforeCleanupFileHandler(sender As Object, e As CbfilterBeforeCleanupFileEventArgs)

Public Class CbfilterBeforeCleanupFileEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ResultCode As Integer
End Class

Remarks

This event fires before a handle to the file or directory specified by FileName is closed. This event differs from BeforeCloseFile in that BeforeCleanupFile fires immediately before an open handle to the specified file or directory is closed by a process, whereas BeforeCloseFile may be fired much later when the OS itself decides that the file or directory can be formally closed.

Other events may fire for the file or directory in the time between when this event fires and when the BeforeCloseFile event fires. For example, system components such as the memory manager or cache manager may cause the BeforeReadFile and BeforeWriteFile events to fire.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_BEFORE_CLEANUP flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

BeforeCloseFile Event (CBFilter Component)

This event fires before a file or directory is closed.

Syntax

public event OnBeforeCloseFileHandler OnBeforeCloseFile;

public delegate void OnBeforeCloseFileHandler(object sender, CbfilterBeforeCloseFileEventArgs e);

public class CbfilterBeforeCloseFileEventArgs : EventArgs {
  public string FileName { get; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnBeforeCloseFile As OnBeforeCloseFileHandler

Public Delegate Sub OnBeforeCloseFileHandler(sender As Object, e As CbfilterBeforeCloseFileEventArgs)

Public Class CbfilterBeforeCloseFileEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ResultCode As Integer
End Class

Remarks

This event fires before the file or directory specified by FileName is closed.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_BEFORE_CLOSE flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information.

If the file or directory was marked for deletion earlier, the BeforeDeleteFile will fire shortly before this event.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

BeforeCreateFile Event (CBFilter Component)

This event fires before a file or directory is created.

Syntax

public event OnBeforeCreateFileHandler OnBeforeCreateFile;

public delegate void OnBeforeCreateFileHandler(object sender, CbfilterBeforeCreateFileEventArgs e);

public class CbfilterBeforeCreateFileEventArgs : EventArgs {
  public string FileName { get; }
  public int ExistingAttributes { get; }
  public bool Isolate { get; set; }
  public string BackendFileName { get; set; }
  public int DesiredAccess { get; set; }
  public int Attributes { get; set; }
  public int ShareMode { get; set; }
  public int Options { get; set; }
  public int CreateDisposition { get; set; }
  public IntPtr SecurityDescriptor { get; }
  public int Length { get; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public bool ProcessRequest { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnBeforeCreateFile As OnBeforeCreateFileHandler

Public Delegate Sub OnBeforeCreateFileHandler(sender As Object, e As CbfilterBeforeCreateFileEventArgs)

Public Class CbfilterBeforeCreateFileEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public ReadOnly Property ExistingAttributes As Integer
  Public Property Isolate As Boolean
  Public Property BackendFileName As String
  Public Property DesiredAccess As Integer
  Public Property Attributes As Integer
  Public Property ShareMode As Integer
  Public Property Options As Integer
  Public Property CreateDisposition As Integer
  Public ReadOnly Property SecurityDescriptor As IntPtr
  Public ReadOnly Property Length As Integer
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ProcessRequest As Boolean
  Public Property ResultCode As Integer
End Class

Remarks

This event fires before the file or directory specified by FileName is created. Please refer to the File Create/Open Events topic for more information about how the component determines whether to fire this event or BeforeOpenFile.

Applications may use this event to modify the request's parameters, or to block the request entirely. To do the latter, set ProcessRequest to false; this has the same effect as returning ACCESS_DENIED.

To redirect a request to another file or directory, use the ReparseFileName event, which is fired shortly after this event.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_BEFORE_CREATE flag.

Note: Applications must have the FilterOwnRequests configuration setting enabled if they wish to filter their own file/directory creation requests.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

When extended rules are used or the AlwaysRequestAttributesOnOpen configuration setting is enabled, the driver requests attributes of the entity from the filesystem and passes them to ExistingAttributes. If the attributes are not requested, this parameter contains 0.

Isolation-related functionality is under construction.

The initial values of DesiredAccess, Attributes, ShareMode, and CreateDisposition parameters reflect the values that were passed for the similarly named parameters of the Windows API's CreateFile function (or, more accurately, the values carried by the IRP_MJ_CREATE Internet Relay Programming).

DesiredAccess may contain one or more of the following access flags:

DESIRED_ACCESS_FILE_LIST_DIRECTORY0x00000001For a directory, the right to list the contents of the directory.

DESIRED_ACCESS_FILE_READ_DATA0x00000001For a file object, the right to read the corresponding file data.

For a directory object, the right to read the corresponding directory data.

DESIRED_ACCESS_FILE_ADD_FILE0x00000002For a directory, the right to create a file in the directory.

DESIRED_ACCESS_FILE_WRITE_DATA0x00000002For a file object, the right to write data to the file.

For a directory object, the right to create a file in the directory

DESIRED_ACCESS_FILE_ADD_SUBDIRECTORY0x00000004For a directory, the right to create a subdirectory.

DESIRED_ACCESS_FILE_APPEND_DATA0x00000004For a file object, the right to append data to the file.

(For local files, write operations will not overwrite existing data if this flag is specified without FILE_WRITE_DATA.) For a directory object, the right to create a subdirectory (FILE_ADD_SUBDIRECTORY).

DESIRED_ACCESS_FILE_READ_EA0x00000008The right to read extended file attributes.

DESIRED_ACCESS_FILE_WRITE_EA0x00000010The right to write extended file attributes.

DESIRED_ACCESS_FILE_EXECUTE0x00000020For a native code file, the right to execute the file.

This access right given to scripts may cause the script to be executable, depending on the script interpreter.

DESIRED_ACCESS_FILE_DELETE_CHILD0x00000040For a directory, the right to delete a directory and all the files it contains, including read-only files.

DESIRED_ACCESS_FILE_READ_ATTRIBUTES0x00000080The right to read file attributes.

DESIRED_ACCESS_FILE_WRITE_ATTRIBUTES0x00000100The right to write file attributes.

DESIRED_ACCESS_READ_CONTROL0x00020000The right to read the information in the file or directory object's security descriptor.

This does not include the information in the SACL.

DESIRED_ACCESS_STANDARD_RIGHTS_READ0x00020000Includes READ_CONTROL, which is the right to read the information in the file or directory object's security descriptor.

This does not include the information in the SACL.

DESIRED_ACCESS_STANDARD_RIGHTS_WRITE0x00020000Same as STANDARD_RIGHTS_READ

DESIRED_ACCESS_STANDARD_RIGHTS_EXECUTE0x00020000Same as STANDARD_RIGHTS_READ

DESIRED_ACCESS_SYNCHRONIZE0x00100000The right to use the object for synchronization.

This enables a thread to wait until the object is in the signaled state. Some object types do not support this access right.

DESIRED_ACCESS_FILE_ALL_ACCESS0x001F01FFAll possible access rights for a file.

DESIRED_ACCESS_FILE_GENERIC_READ0x00120089A combinarion of flags that allow reading of the file.

Note: Don't match received values against this flag. Instead, use flags that specify the rights that you want to verify or add/remove.

DESIRED_ACCESS_FILE_GENERIC_WRITE0x00120116A combinarion of flags that allow modifications to the file.

Note: Don't match received values against this flag. Instead, use flags that specify the rights that you want to verify or add/remove.

DESIRED_ACCESS_FILE_GENERIC_EXECUTE0x001200A0A combinarion of flags that allow execution of the file.

Note: Don't match received values against this flag. Instead, use flags that specify the rights that you want to verify or add/remove.

Attributes may contain one or more of the following attributes:

FILE_SYS_ATTR_READ_ONLY0x00000001The file is read-only.

Applications can read the file, but cannot write to it or delete it. This attribute is not honored on directories.

FILE_SYS_ATTR_HIDDEN0x00000002The file or directory is hidden.

The file is not included in an ordinary directory listing.

FILE_SYS_ATTR_SYSTEM0x00000004A file or directory that the operating system uses a part of, or uses exclusively.

FILE_SYS_ATTR_DIRECTORY0x00000010The entry is a directory.

FILE_SYS_ATTR_ARCHIVE0x00000020The entry is an archive file or directory.

Applications typically use this attribute to mark files for backup or removal.

FILE_SYS_ATTR_NORMAL0x00000080A file doesn't have other attributes set.

This attribute is valid only when used alone.

FILE_SYS_ATTR_TEMPORARY0x00000100A file that is being used for temporary storage.

File systems avoid writing data back to mass storage if sufficient cache memory is available, because typically, an application deletes a temporary file after the handle is closed. In that scenario, the system can entirely avoid writing the data. Otherwise, the data are written after the handle is closed.

FILE_SYS_ATTR_SPARSE_FILE0x00000200A file that is a sparse file.

FILE_SYS_ATTR_REPARSE_POINT0x00000400A file that is a reparse point or a symbolic link.

FILE_SYS_ATTR_COMPRESSED0x00000800A file or directory that is compressed.

For a file, all of the data in the file are compressed. For a directory, compression is the default for newly created files and subdirectories. A filesystem implementation can make use of this attribute by setting the SupportCompressedAttribute property to true and then properly handling the GetFileInfo, EnumerateDirectory, and SetFileAttributes events.

FILE_SYS_ATTR_OFFLINE0x00001000The data of a file are not available immediately.

This attribute indicates that the file data are physically moved to offline storage.

FILE_SYS_ATTR_NOT_CONTENT_INDEXED0x00002000The file or directory is not to be indexed by the content indexing service.

FILE_SYS_ATTR_ENCRYPTED0x00004000A file or directory that is encrypted.

For a file, all data streams in the file are encrypted. For a directory, encryption is the default for newly created files and subdirectories.

Note: This flag is used by NTFS and the OS sends undocumented requests to the filesystem based on this flag. The flag should not be used for files in custom filesystem implementations.

FILE_SYS_ATTR_VIRTUAL0x00010000Reserved.

Note: This flag is reserved by the OS and should not be used for files in custom filesystem implementations.

FILE_SYS_ATTR_RECALL_ON_OPEN0x00040000The file or directory has no physical representation on the local system; the item is virtual.

Opening the item will be more expensive than normal (e.g., it will cause at least some of it to be fetched from a remote store). This flag is reported by filesystems during directory enumerations.

ShareMode may contain zero or more of the following share mode flags:

FILESYS_SHARE_READ0x00000001Enables subsequent open operations on a file or device to request read access.

Enables subsequent open operations to request read access; otherwise, no process can open the file or device if it requests read access. If this flag is not specified, but the file or device has been opened for read access, the function fails.

FILESYS_SHARE_WRITE0x00000002Enables subsequent open operations on a file or device to request write access.

Enables subsequent open operations to request write access; otherwise, no process can open the file or device if it requests write access. If this flag is not specified, but the file or device has been opened for write access or has a file mapping with write access, the function fails.

FILESYS_SHARE_DELETE0x00000004Enables subsequent open operations on a file or device to request delete access.

Enables subsequent open operations to request delete access; otherwise, no process can open the file or device if it requests delete access. If this flag is not specified, but the file or device has been opened for delete access, the function fails.

Note: Delete access allows both delete and rename operations.

CreateDisposition may contain one of the following values:

FILE_DISPOSITION_CREATE_NEW0x00000001Creates a new file, only if it does not already exist.

If the specified file exists, the operation fails with an "already exists" error.

FILE_DISPOSITION_CREATE_ALWAYS0x00000002Creates a new file, always.

If the specified file exists and is writable, the system overwrites the file. If the specified file does not exist and is a valid path, a new file is created.

FILE_DISPOSITION_OPEN_EXISTING0x00000003Opens a file, only if it exists

If the specified file does not exist, opening fails.

FILE_DISPOSITION_OPEN_ALWAYS0x00000004Opens a file, always.

If the specified file exists, the operation succeeds. If the specified file does not exist and is a valid path to a writable location, the a file is created.

FILE_DISPOSITION_TRUNCATE_EXISTING0x00000005Opens a file and truncates it so that its size is zero bytes, only if it exists.

If the specified file does not exist, the operation fails with a "file not found" error.

Options contains the flags that are described in the CreateOptions parameter of the Native API's ZwCreateFile function. Most of those flags correspond to flags passed in the FlagsAndAttributes parameter of the Windows API's CreateFile function, but some flags are specific to Native API. If you need those flags, check both functions' descriptions.

Please refer to Microsoft's documentation for detailed information about these constants.

To determine whether the request is for a file or a directory, compare Attributes against the FILE_SYS_ATTR_DIRECTORY constant, as follows: // Check whether the request is for a file or a directory. bool isDirectory = Attributes & FILE_SYS_ATTR_DIRECTORY == FILE_SYS_ATTR_DIRECTORY; FILE_SYS_ATTR_DIRECTORY will be present only if it was specified by the calling process; its presence or absence does not indicate the real presence of the attribute on the file or directory on disk.

To determine whether a file will be deleted when its last handle is closed, compare Options against the Windows API's FILE_FLAG_DELETE_ON_CLOSE constant, as follows: // Check whether the file will be deleted on close. bool deleteOnClose = Options & FILE_FLAG_DELETE_ON_CLOSE == FILE_FLAG_DELETE_ON_CLOSE;

Note: Files can be deleted in different ways, so do not use this check to take actions related to tracking file deletion operations. Instead, use the events related to file deletion.

To prevent a file or directory from being opened, set the ResultCode parameter to a non-zero value (typically ERROR_ACCESS_DENIED (5)).

When a file or directory is created using the CreateFile() Windows API function, a caller can specify the security descriptor with the security information. This security information should be applied to a newly created file or directory. The component passes this security information in the SecurityInformation and SecurityDescriptor parameters, when the PassSecurityInFileOpenEvents configuration setting is enabled. If this configuration setting is omitted, the corresponding parameters are empty.

The SecurityInformation parameter reflects which pieces of security information, of those present in SecurityDescriptor, are valid and should have been applied. Please refer to Microsoft's SECURITY_INFORMATION data type documentation for more information about possible values.

The SecurityDescriptor parameter points to a memory buffer that contains the security information. The Length parameter reflects the length of this data, in bytes. Please see the Buffer Parameters topic for more information on how to work with memory buffer event parameters.

The data are formatted as a SECURITY_DESCRIPTOR structure in self-relative format; please refer to the Microsoft's documentation for more information.

If an application needs to alter the security information, it can do this by placing up to Length bytes of information into the SecurityDescriptor buffer.

Note: Changing the security data is possible only when the PassSecurityInFileOpenEvents configuration setting is enabled.

If the capacity reflected by the Length parameter is not enough to accommodate the security information, set LengthNeeded to the number of bytes necessary to hold the data, and return the ERROR_INSUFFICIENT_BUFFER error code via ResultCode.

The ProcessRequest parameter controls whether the request is sent onward for further processing by subsequent filter drivers and the filesystem; it is true by default.

If the Options contains the FILE_FLAG_DELETE_ON_CLOSE flag, the BeforeCanFileBeDeleted event will fire before this event.

If the file is opened with extended attributes passed in the request, the BeforeSetEa event will fire after this event.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

BeforeCreateHardLink Event (CBFilter Component)

This event fires before a hard link is created.

Syntax

Remarks

This event fires before a hard link to the file specified by FileName is created. Please refer to Microsoft's Hard Links article for more information about hard links.

Applications may use this event to modify the request's parameters, or to block the request entirely. To do the latter, set ProcessRequest to false.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_BEFORE_CREATE_HARD_LINK flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The LinkName parameter reflects the name of the new hard link.

The ReplaceIfExists parameter specifies what to do if a hard link with the specified LinkName already exists. If this parameter is true, the new hard link will replace the existing hard link; if this parameter is false, the operation will fail.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information.

The ProcessRequest parameter controls whether the request is sent onward for further processing by subsequent filter drivers and the filesystem; it is true by default.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

BeforeDeleteFile Event (CBFilter Component)

This event fires before a file or directory is deleted.

Syntax

public event OnBeforeDeleteFileHandler OnBeforeDeleteFile;

public delegate void OnBeforeDeleteFileHandler(object sender, CbfilterBeforeDeleteFileEventArgs e);

public class CbfilterBeforeDeleteFileEventArgs : EventArgs {
  public string FileName { get; }
  public int RequestType { get; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnBeforeDeleteFile As OnBeforeDeleteFileHandler

Public Delegate Sub OnBeforeDeleteFileHandler(sender As Object, e As CbfilterBeforeDeleteFileEventArgs)

Public Class CbfilterBeforeDeleteFileEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public ReadOnly Property RequestType As Integer
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ResultCode As Integer
End Class

Remarks

This event fires before the file or directory specified by FileName is deleted. More specifically, this event is fired before the final IRM_MJ_CLOSE Internet Relay Programming (IRP) is processed by the filesystem and before BeforeCloseFile fires.

Applications may use this event to obtain information about the specified file or directory, which still exists at the time this event fires. This event cannot be used to prevent a deletion; use the BeforeCanFileBeDeleted event instead.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_BEFORE_DELETE flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The RequestType indicates which kind of system request resulted in firing this event. It can be one of the following:

DEL_REQ_OPEN_FLAG0x1The file or directory is opened with the FILE_FLAG_DELETE_ON_CLOSE flag

DEL_REQ_SET_DISPOSITION0x2The system has sent the IRP_MJ_SET_INFORMATION request with SetFileDisposition structure as a parameter.

This request usually is sent using the NtSetInformationFile() Windows native API function.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

BeforeDeleteReparsePoint Event (CBFilter Component)

This event fires when the OS wants to delete a reparse point from a file or directory.

Syntax

public event OnBeforeDeleteReparsePointHandler OnBeforeDeleteReparsePoint;

public delegate void OnBeforeDeleteReparsePointHandler(object sender, CbfilterBeforeDeleteReparsePointEventArgs e);

public class CbfilterBeforeDeleteReparsePointEventArgs : EventArgs {
  public string FileName { get; }
  public IntPtr ReparseBuffer { get; }
  public int BufferLength { get; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public bool ProcessRequest { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnBeforeDeleteReparsePoint As OnBeforeDeleteReparsePointHandler

Public Delegate Sub OnBeforeDeleteReparsePointHandler(sender As Object, e As CbfilterBeforeDeleteReparsePointEventArgs)

Public Class CbfilterBeforeDeleteReparsePointEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public ReadOnly Property ReparseBuffer As IntPtr
  Public ReadOnly Property BufferLength As Integer
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ProcessRequest As Boolean
  Public Property ResultCode As Integer
End Class

Remarks

This event fires before the OS deletes a reparse point from a file or directory specified by FileName.

Note: The file or directory is not deleted, only the reparse point is.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_BEFORE_DELETE_REPARSE_POINT flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The ReparseBuffer parameter points to a memory buffer that specifies the known reparse point information. This information is provided for convenience. Please see the Buffer Parameters topic for more information on how to work with memory buffer event parameters.

Please refer to the Reparse Points topic for more information.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information.

The ProcessRequest parameter controls whether the request is sent onward for further processing by subsequent filter drivers and the filesystem; it is true by default.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

BeforeEnumerateDirectory Event (CBFilter Component)

This event fires when an enumeration request is sent by the OS.

Syntax

public event OnBeforeEnumerateDirectoryHandler OnBeforeEnumerateDirectory;

public delegate void OnBeforeEnumerateDirectoryHandler(object sender, CbfilterBeforeEnumerateDirectoryEventArgs e);

public class CbfilterBeforeEnumerateDirectoryEventArgs : EventArgs {
  public string DirectoryName { get; }
  public int Flags { get; }
  public string Mask { get; }
  public int Index { get; }
  public IntPtr DirectoryContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public IntPtr EnumerationContext { get; set; }
  public bool ProcessRequest { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnBeforeEnumerateDirectory As OnBeforeEnumerateDirectoryHandler

Public Delegate Sub OnBeforeEnumerateDirectoryHandler(sender As Object, e As CbfilterBeforeEnumerateDirectoryEventArgs)

Public Class CbfilterBeforeEnumerateDirectoryEventArgs Inherits EventArgs
  Public ReadOnly Property DirectoryName As String
  Public ReadOnly Property Flags As Integer
  Public ReadOnly Property Mask As String
  Public ReadOnly Property Index As Integer
  Public Property DirectoryContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property EnumerationContext As IntPtr
  Public Property ProcessRequest As Boolean
  Public Property ResultCode As Integer
End Class

Remarks

This event fires when the OS sends a request for reading one or more entries of the directory specified by DirectoryName.

Applications may use this event to record the request and optionally block it.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_BEFORE_ENUMERATE_DIRECTORY flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The Flags parameter specifies supplementary information about enumeration. It is a combination of zero or more values:

FS_ENUM_RESTART_SCAN1The requestor specified that directory enumeration must be restarted.

FS_ENUM_RETURN_SINGLE_ENTRY2One entry should be returned.

FS_ENUM_INDEX_SPECIFIED4The requestor specified the index to start enumeration from.

If the Flags parameter contains FS_ENUM_INDEX_SPECIFIED, the Index parameter contains the index as provided by the OS.

The Mask parameter contains the mask for the enumeration. This value may contain any combination of valid filename characters and wildcards (the * and ? characters). Alternatively, it may be an exact filename (i.e., a value without any wildcards), as some applications query file information by specifying an exact filename in an enumeration. When TranslateDOSCharsInEnumMasks is false, this parameter may contain a so-called DOS wildcard (please, refer to the description of this setting for more information). The mask can also be empty in rare cases: this happens when the OS request is a continuation of a previous enumeration with a valid non-zero Index.

The DirectoryContext, HandleContext, and EnumerationContext parameters are placeholders for application-defined data associated with the directory, specific handle, and enumeration, respectively. (For general-purpose events, the DirectoryContext is called FileContext instead.) DirectoryContext corresponds to the FileContext in the file/directory creation, opening, and closing events. Please refer to the Contexts topic for more information.

The ProcessRequest parameter controls whether the request is sent onward for further processing by subsequent filter drivers and the filesystem; it is true by default.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

BeforeFilterAttachToVolume Event (CBFilter Component)

This event fires before the filter attaches to a newly mounted filesystem volume.

Syntax

public event OnBeforeFilterAttachToVolumeHandler OnBeforeFilterAttachToVolume;

public delegate void OnBeforeFilterAttachToVolumeHandler(object sender, CbfilterBeforeFilterAttachToVolumeEventArgs e);

public class CbfilterBeforeFilterAttachToVolumeEventArgs : EventArgs {
  public string VolumeName { get; }
  public bool SkipVolume { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnBeforeFilterAttachToVolume As OnBeforeFilterAttachToVolumeHandler

Public Delegate Sub OnBeforeFilterAttachToVolumeHandler(sender As Object, e As CbfilterBeforeFilterAttachToVolumeEventArgs)

Public Class CbfilterBeforeFilterAttachToVolumeEventArgs Inherits EventArgs
  Public ReadOnly Property VolumeName As String
  Public Property SkipVolume As Boolean
  Public Property ResultCode As Integer
End Class

Remarks

This event fires before the filter attaches to the newly mounted filesystem volume specified by VolumeName. Please refer to the FireVolumeEvents property for more information.

Applications need to handle this event only if the FireVolumeEvents property includes the FS_MOUNT_CONTROL flag.

The VolumeName parameter's value is always an NT native format in this event (unlike the other volume-related events, listed below, where its format depends on the ResolveNtDeviceToDriveLetter configuration setting). It is therefore recommended that applications add volume-specific rules, if desired, during the AfterFilterAttachToVolume event rather than this one. Applications can obtain additional information about a volume by retrieving its GUID using the GetVolumeGUID method, and then using that GUID to call various Windows API functions.

The SkipVolume parameter specifies whether the component's system driver should skip the specified volume (i.e., not attach the filter to it). Setting this parameter to true will cause all filesystem operations that target to volume to be completely ignored by the component's system driver. It also will prevent any of the following events from firing for the volume:

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

Applications must be aware that this event fires as a direct response to a filesystem state change (mount or unmount). Various system components or third-party actors can perform supplementary filesystem mounting and unmounting during main unmount operations (e.g., Volume Service is one such component). This can cause seemingly excessive events to be fired, and sometimes they can be fired out of order (such as two *Attach or *Detach events fired in a row).

BeforeFsctl Event (CBFilter Component)

This event fires before an IRP_MJ_FILE_SYSTEM_CONTROL request is processed.

Syntax

public event OnBeforeFsctlHandler OnBeforeFsctl;

public delegate void OnBeforeFsctlHandler(object sender, CbfilterBeforeFsctlEventArgs e);

public class CbfilterBeforeFsctlEventArgs : EventArgs {
  public string FileName { get; }
  public int FsControlCode { get; }
  public IntPtr InBuffer { get; }
  public int InBufferLength { get; }
  public int InBufferValidBytes { get; set; }
  public IntPtr OutBuffer { get; }
  public int OutBufferLength { get; }
  public int OutBufferValidBytes { get; set; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public bool ProcessRequest { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnBeforeFsctl As OnBeforeFsctlHandler

Public Delegate Sub OnBeforeFsctlHandler(sender As Object, e As CbfilterBeforeFsctlEventArgs)

Public Class CbfilterBeforeFsctlEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public ReadOnly Property FsControlCode As Integer
  Public ReadOnly Property InBuffer As IntPtr
  Public ReadOnly Property InBufferLength As Integer
  Public Property InBufferValidBytes As Integer
  Public ReadOnly Property OutBuffer As IntPtr
  Public ReadOnly Property OutBufferLength As Integer
  Public Property OutBufferValidBytes As Integer
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ProcessRequest As Boolean
  Public Property ResultCode As Integer
End Class

Remarks

This event fires before an IRP_MJ_FILE_SYSTEM_CONTROL (FSCTL) request is processed. Such requests are sent using the Windows API's DeviceIoControl function (user mode), or ZwFsControlFile function (kernel mode); please refer to Microsoft's documentation for more information.

Applications may use this event to modify the input data (if there are any) before the request continues onward. Applications that choose to do this must do the following:

  1. Copy no more than InBufferLength bytes into InBuffer.
  2. Update the InBufferValidBytes parameter's value afterward so that it correctly reflects the amount of data in InBuffer.

Alternatively, applications may use this event to handle the request (preventing it from continuing onward), in which case they must do the following:

  1. Copy no more than OutBufferLength bytes into OutBuffer.
  2. Update the OutBufferValidBytes parameter's value afterward so that it correctly reflects the amount of data in OutBuffer.
  3. Set ProcessRequest to false to indicate that the request has been handled and should not continue onward.
(The first two steps are not applicable if the requested operation is not expected to return data.)

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_BEFORE_FSCTL flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The FileName parameter reflects the file, directory, or volume targeted by the request.

The FsControlCode parameter reflects the requested filesystem control code (FSCTL).

The InBuffer parameter points to a memory buffer that contains the data required to perform the operation. The InBufferLength and InBufferValidBytes parameters reflect the capacity of InBuffer and the length of the data it contains (respectively), in bytes; InBufferValidBytes may be less than InBufferLength (unless the request did not include data, in which case both will be 0).

The OutBuffer parameter points to a memory buffer that receives the data returned by the operation. The OutBufferLength and OutBufferValidBytes parameters reflect the capacity of OutBuffer and the length of the data it contains (respectively), in bytes; OutBufferValidBytes may be less than OutBufferLength (unless the operation is not expected to return data, in which case both will be 0).

Please see the Buffer Parameters topic for more information on how to work with memory buffer event parameters.

The ProcessRequest parameter controls whether the request is sent onward for further processing by subsequent filter drivers and the filesystem; it is true by default.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

BeforeGetFileSecurity Event (CBFilter Component)

This event fires before a file or directory's security attributes are retrieved.

Syntax

public event OnBeforeGetFileSecurityHandler OnBeforeGetFileSecurity;

public delegate void OnBeforeGetFileSecurityHandler(object sender, CbfilterBeforeGetFileSecurityEventArgs e);

public class CbfilterBeforeGetFileSecurityEventArgs : EventArgs {
  public string FileName { get; }
  public int SecurityInformation { get; }
  public IntPtr SecurityDescriptor { get; }
  public int Length { get; }
  public int LengthNeeded { get; set; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public bool ProcessRequest { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnBeforeGetFileSecurity As OnBeforeGetFileSecurityHandler

Public Delegate Sub OnBeforeGetFileSecurityHandler(sender As Object, e As CbfilterBeforeGetFileSecurityEventArgs)

Public Class CbfilterBeforeGetFileSecurityEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public ReadOnly Property SecurityInformation As Integer
  Public ReadOnly Property SecurityDescriptor As IntPtr
  Public ReadOnly Property Length As Integer
  Public Property LengthNeeded As Integer
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ProcessRequest As Boolean
  Public Property ResultCode As Integer
End Class

Remarks

This event fires before security attributes are retrieved for the file or directory specified by FileName.

Note: This event will not fire every time a file or directory is accessed. To check file security upon each access to a file or directory, implement the file create and open events and perform the necessary checks there instead.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_BEFORE_GET_SECURITY flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The SecurityInformation parameter indicates which pieces of security information are requested. Please refer to Microsoft's SECURITY_INFORMATION data-type documentation for more information about possible values.

The SecurityDescriptor parameter points to a memory buffer that receives the requested security information. The buffer referenced by the SecurityDescriptor parameter may be modified by the event handler if the operation is completed without passing it further to other filters and the filesystem driver. The Length parameter reflects the capacity of the SecurityDescriptor buffer, in bytes.

If the capacity reflected by the Length parameter is not sufficient to accommodate the security information, set LengthNeeded to the number of bytes necessary to hold the data, and return the ERROR_INSUFFICIENT_BUFFER error code via ResultCode.

Please see the Buffer Parameters topic for more information on how to work with memory buffer event parameters.

The returned data will be formatted as a SECURITY_DESCRIPTOR structure in self-relative format; please refer to the Microsoft's documentation for more information.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information.

The ProcessRequest parameter controls whether the request is sent onward for further processing by subsequent filter drivers and the filesystem; it is true by default.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

BeforeGetReparsePoint Event (CBFilter Component)

This event fires when the OS wants to read a reparse point for a file or directory.

Syntax

public event OnBeforeGetReparsePointHandler OnBeforeGetReparsePoint;

public delegate void OnBeforeGetReparsePointHandler(object sender, CbfilterBeforeGetReparsePointEventArgs e);

public class CbfilterBeforeGetReparsePointEventArgs : EventArgs {
  public string FileName { get; }
  public IntPtr ReparseBuffer { get; }
  public int ReparseBufferLength { get; set; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public bool ProcessRequest { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnBeforeGetReparsePoint As OnBeforeGetReparsePointHandler

Public Delegate Sub OnBeforeGetReparsePointHandler(sender As Object, e As CbfilterBeforeGetReparsePointEventArgs)

Public Class CbfilterBeforeGetReparsePointEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public ReadOnly Property ReparseBuffer As IntPtr
  Public Property ReparseBufferLength As Integer
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ProcessRequest As Boolean
  Public Property ResultCode As Integer
End Class

Remarks

This event fires when the OS wants to read a reparse point for the file or directory specified by FileName.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_BEFORE_GET_REPARSE_POINT flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

If an application desires to handle the event and does not pass the request further, it needs to fill ReparseBuffer with the reparse point data associated with the specified file or directory and set ReparseBufferLength to the number of bytes written. The ReparseBufferLength parameter's initial value reflects the capacity of the memory buffer pointed to by ReparseBuffer. If the buffer is too small to hold all of the reparse point data, then the application should write as much data to it as possible, set ReparseBufferLength appropriately, and return the ERROR_MORE_DATA error code via ResultCode.

Please refer to the Reparse Points topic for more information.

Please see the Buffer Parameters topic for more information on how to work with memory buffer event parameters.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information.

Depending on how the request originator accessed the specified file or directory, it may or may not currently be open. The FileContext and HandleContext parameters will be absent if it is not open, in which case they will be IntPtr.Zero.

The ProcessRequest parameter controls whether the request is sent onward for further processing by subsequent filter drivers and the filesystem; it is true by default.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

BeforeIoctl Event (CBFilter Component)

This event fires before an IRP_MJ_DEVICE_CONTROL request is processed.

Syntax

public event OnBeforeIoctlHandler OnBeforeIoctl;

public delegate void OnBeforeIoctlHandler(object sender, CbfilterBeforeIoctlEventArgs e);

public class CbfilterBeforeIoctlEventArgs : EventArgs {
  public string FileName { get; }
  public int IoControlCode { get; }
  public IntPtr InBuffer { get; }
  public int InBufferLength { get; }
  public int InBufferValidBytes { get; set; }
  public IntPtr OutBuffer { get; }
  public int OutBufferLength { get; }
  public int OutBufferValidBytes { get; set; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public bool ProcessRequest { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnBeforeIoctl As OnBeforeIoctlHandler

Public Delegate Sub OnBeforeIoctlHandler(sender As Object, e As CbfilterBeforeIoctlEventArgs)

Public Class CbfilterBeforeIoctlEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public ReadOnly Property IoControlCode As Integer
  Public ReadOnly Property InBuffer As IntPtr
  Public ReadOnly Property InBufferLength As Integer
  Public Property InBufferValidBytes As Integer
  Public ReadOnly Property OutBuffer As IntPtr
  Public ReadOnly Property OutBufferLength As Integer
  Public Property OutBufferValidBytes As Integer
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ProcessRequest As Boolean
  Public Property ResultCode As Integer
End Class

Remarks

This event fires before an IRP_MJ_DEVICE_CONTROL (IOCTL) request is processed. Such requests are sent using the Windows API's DeviceIoControl function (user mode), or ZwDeviceIoControlFile function (kernel mode). Please refer to Microsoft's documentation for more information.

Applications may use this event to modify the input data (if there are any) before the request continues onward. Applications that choose to do this must do the following:

  1. Copy no more than InBufferLength bytes into InBuffer.
  2. Update the InBufferValidBytes parameter's value afterward so that it correctly reflects the amount of data in InBuffer.

Alternatively, applications may use this event to handle the request (preventing it from continuing onward), in which case they must do the following:

  1. Copy no more than OutBufferLength bytes into OutBuffer.
  2. Update the OutBufferValidBytes parameter's value afterward so that it correctly reflects the amount of data in OutBuffer.
  3. Set ProcessRequest to false to indicate that the request has been handled and should not continue onward.
(The first two steps are not applicable if the requested operation is not expected to return data.)

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_BEFORE_IOCTL flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The FileName parameter reflects the file, directory, or volume targeted by the request.

The IoControlCode parameter reflects the requested I/O control code (IOCTL).

The InBuffer parameter points to a memory buffer that contains the data required to perform the operation. The InBufferLength and InBufferValidBytes parameters reflect the capacity of InBuffer and the length of the data it contains (respectively), in bytes; InBufferValidBytes may be less than InBufferLength (unless the request did not include data, in which case both will be 0).

The OutBuffer parameter points to a memory buffer that receives the data returned by the operation. The OutBufferLength and OutBufferValidBytes parameters reflect the capacity of OutBuffer and the length of the data it contains (respectively), in bytes; OutBufferValidBytes may be less than OutBufferLength (unless the operation is not expected to return data, in which case both will be 0).

Please see the Buffer Parameters topic for more information on how to work with memory buffer event parameters.

The ProcessRequest parameter controls whether the request is sent onward for further processing by subsequent filter drivers and the filesystem; it is true by default.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

BeforeLock Event (CBFilter Component)

This event fires before a range of bytes in a file is locked.

Syntax

public event OnBeforeLockHandler OnBeforeLock;

public delegate void OnBeforeLockHandler(object sender, CbfilterBeforeLockEventArgs e);

public class CbfilterBeforeLockEventArgs : EventArgs {
  public string FileName { get; }
  public long Offset { get; set; }
  public long Length { get; set; }
  public long Key { get; }
  public bool FailImmediately { get; set; }
  public bool ExclusiveLock { get; set; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public bool ProcessRequest { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnBeforeLock As OnBeforeLockHandler

Public Delegate Sub OnBeforeLockHandler(sender As Object, e As CbfilterBeforeLockEventArgs)

Public Class CbfilterBeforeLockEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public Property Offset As Long
  Public Property Length As Long
  Public ReadOnly Property Key As Long
  Public Property FailImmediately As Boolean
  Public Property ExclusiveLock As Boolean
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ProcessRequest As Boolean
  Public Property ResultCode As Integer
End Class

Remarks

This event fires before a range of bytes in the file specified by FileName is locked; This request is made either by the OS, or on behalf of a user mode application that called the Windows API's LockFile or LockFileEx function.

Applications may use this event to modify the request's parameters.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_BEFORE_LOCK_CONTROL flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The Offset parameter specifies the byte offset where the byte range lock should start.

The Length parameter specifies the length of the byte range lock.

The Key parameter reflects the key that the byte range lock will be associated with. This key is used to identify the byte range lock in later unlock-by-key requests.

The FailImmediately parameter specifies whether the request should fail if the lock cannot be granted immediately.

The ExclusiveLock parameter specifies whether the byte range lock should be exclusive (true) or shared (false).

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information.

The ProcessRequest parameter controls whether the request is sent onward for further processing by subsequent filter drivers and the filesystem; it is true by default.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

BeforeOpenFile Event (CBFilter Component)

This event fires before a file or directory is opened.

Syntax

public event OnBeforeOpenFileHandler OnBeforeOpenFile;

public delegate void OnBeforeOpenFileHandler(object sender, CbfilterBeforeOpenFileEventArgs e);

public class CbfilterBeforeOpenFileEventArgs : EventArgs {
  public string FileName { get; }
  public int ExistingAttributes { get; }
  public bool Isolate { get; set; }
  public string BackendFileName { get; set; }
  public int DesiredAccess { get; set; }
  public int Attributes { get; set; }
  public int ShareMode { get; set; }
  public int Options { get; set; }
  public int CreateDisposition { get; set; }
  public IntPtr SecurityDescriptor { get; }
  public int Length { get; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public bool ProcessRequest { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnBeforeOpenFile As OnBeforeOpenFileHandler

Public Delegate Sub OnBeforeOpenFileHandler(sender As Object, e As CbfilterBeforeOpenFileEventArgs)

Public Class CbfilterBeforeOpenFileEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public ReadOnly Property ExistingAttributes As Integer
  Public Property Isolate As Boolean
  Public Property BackendFileName As String
  Public Property DesiredAccess As Integer
  Public Property Attributes As Integer
  Public Property ShareMode As Integer
  Public Property Options As Integer
  Public Property CreateDisposition As Integer
  Public ReadOnly Property SecurityDescriptor As IntPtr
  Public ReadOnly Property Length As Integer
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ProcessRequest As Boolean
  Public Property ResultCode As Integer
End Class

Remarks

This event fires before the file or directory specified by FileName is opened. Please refer to the File Create/Open Events topic for more information about how the component determines whether to fire this event or BeforeCreateFile.

Applications may use this event to modify the request's parameters, or to block the request entirely. To do the latter, set ProcessRequest to false; this has the same effect as returning ACCESS_DENIED.

To redirect a request to another file or directory, use the ReparseFileName event, which is fired shortly after this event.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_BEFORE_OPEN flag.

Note: Applications must have the FilterOwnRequests configuration setting enabled if they wish to filter their own file/directory open requests.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

When extended rules are used or the AlwaysRequestAttributesOnOpen configuration setting is enabled, the driver requests attributes of the entity from the filesystem and passes them to ExistingAttributes. If the attributes are not requested, this parameter contains 0.

Isolation-related functionality is under construction.

The initial values of DesiredAccess, Attributes, ShareMode, and CreateDisposition parameters reflect the values that were passed for the similarly named parameters of the Windows API's CreateFile function (or, more accurately, the values carried by the IRP_MJ_CREATE Internet Relay Programming).

DesiredAccess may contain one or more of the following access flags:

DESIRED_ACCESS_FILE_LIST_DIRECTORY0x00000001For a directory, the right to list the contents of the directory.

DESIRED_ACCESS_FILE_READ_DATA0x00000001For a file object, the right to read the corresponding file data.

For a directory object, the right to read the corresponding directory data.

DESIRED_ACCESS_FILE_ADD_FILE0x00000002For a directory, the right to create a file in the directory.

DESIRED_ACCESS_FILE_WRITE_DATA0x00000002For a file object, the right to write data to the file.

For a directory object, the right to create a file in the directory

DESIRED_ACCESS_FILE_ADD_SUBDIRECTORY0x00000004For a directory, the right to create a subdirectory.

DESIRED_ACCESS_FILE_APPEND_DATA0x00000004For a file object, the right to append data to the file.

(For local files, write operations will not overwrite existing data if this flag is specified without FILE_WRITE_DATA.) For a directory object, the right to create a subdirectory (FILE_ADD_SUBDIRECTORY).

DESIRED_ACCESS_FILE_READ_EA0x00000008The right to read extended file attributes.

DESIRED_ACCESS_FILE_WRITE_EA0x00000010The right to write extended file attributes.

DESIRED_ACCESS_FILE_EXECUTE0x00000020For a native code file, the right to execute the file.

This access right given to scripts may cause the script to be executable, depending on the script interpreter.

DESIRED_ACCESS_FILE_DELETE_CHILD0x00000040For a directory, the right to delete a directory and all the files it contains, including read-only files.

DESIRED_ACCESS_FILE_READ_ATTRIBUTES0x00000080The right to read file attributes.

DESIRED_ACCESS_FILE_WRITE_ATTRIBUTES0x00000100The right to write file attributes.

DESIRED_ACCESS_READ_CONTROL0x00020000The right to read the information in the file or directory object's security descriptor.

This does not include the information in the SACL.

DESIRED_ACCESS_STANDARD_RIGHTS_READ0x00020000Includes READ_CONTROL, which is the right to read the information in the file or directory object's security descriptor.

This does not include the information in the SACL.

DESIRED_ACCESS_STANDARD_RIGHTS_WRITE0x00020000Same as STANDARD_RIGHTS_READ

DESIRED_ACCESS_STANDARD_RIGHTS_EXECUTE0x00020000Same as STANDARD_RIGHTS_READ

DESIRED_ACCESS_SYNCHRONIZE0x00100000The right to use the object for synchronization.

This enables a thread to wait until the object is in the signaled state. Some object types do not support this access right.

DESIRED_ACCESS_FILE_ALL_ACCESS0x001F01FFAll possible access rights for a file.

DESIRED_ACCESS_FILE_GENERIC_READ0x00120089A combinarion of flags that allow reading of the file.

Note: Don't match received values against this flag. Instead, use flags that specify the rights that you want to verify or add/remove.

DESIRED_ACCESS_FILE_GENERIC_WRITE0x00120116A combinarion of flags that allow modifications to the file.

Note: Don't match received values against this flag. Instead, use flags that specify the rights that you want to verify or add/remove.

DESIRED_ACCESS_FILE_GENERIC_EXECUTE0x001200A0A combinarion of flags that allow execution of the file.

Note: Don't match received values against this flag. Instead, use flags that specify the rights that you want to verify or add/remove.

Attributes may contain one or more of the following attributes:

FILE_SYS_ATTR_READ_ONLY0x00000001The file is read-only.

Applications can read the file, but cannot write to it or delete it. This attribute is not honored on directories.

FILE_SYS_ATTR_HIDDEN0x00000002The file or directory is hidden.

The file is not included in an ordinary directory listing.

FILE_SYS_ATTR_SYSTEM0x00000004A file or directory that the operating system uses a part of, or uses exclusively.

FILE_SYS_ATTR_DIRECTORY0x00000010The entry is a directory.

FILE_SYS_ATTR_ARCHIVE0x00000020The entry is an archive file or directory.

Applications typically use this attribute to mark files for backup or removal.

FILE_SYS_ATTR_NORMAL0x00000080A file doesn't have other attributes set.

This attribute is valid only when used alone.

FILE_SYS_ATTR_TEMPORARY0x00000100A file that is being used for temporary storage.

File systems avoid writing data back to mass storage if sufficient cache memory is available, because typically, an application deletes a temporary file after the handle is closed. In that scenario, the system can entirely avoid writing the data. Otherwise, the data are written after the handle is closed.

FILE_SYS_ATTR_SPARSE_FILE0x00000200A file that is a sparse file.

FILE_SYS_ATTR_REPARSE_POINT0x00000400A file that is a reparse point or a symbolic link.

FILE_SYS_ATTR_COMPRESSED0x00000800A file or directory that is compressed.

For a file, all of the data in the file are compressed. For a directory, compression is the default for newly created files and subdirectories. A filesystem implementation can make use of this attribute by setting the SupportCompressedAttribute property to true and then properly handling the GetFileInfo, EnumerateDirectory, and SetFileAttributes events.

FILE_SYS_ATTR_OFFLINE0x00001000The data of a file are not available immediately.

This attribute indicates that the file data are physically moved to offline storage.

FILE_SYS_ATTR_NOT_CONTENT_INDEXED0x00002000The file or directory is not to be indexed by the content indexing service.

FILE_SYS_ATTR_ENCRYPTED0x00004000A file or directory that is encrypted.

For a file, all data streams in the file are encrypted. For a directory, encryption is the default for newly created files and subdirectories.

Note: This flag is used by NTFS and the OS sends undocumented requests to the filesystem based on this flag. The flag should not be used for files in custom filesystem implementations.

FILE_SYS_ATTR_VIRTUAL0x00010000Reserved.

Note: This flag is reserved by the OS and should not be used for files in custom filesystem implementations.

FILE_SYS_ATTR_RECALL_ON_OPEN0x00040000The file or directory has no physical representation on the local system; the item is virtual.

Opening the item will be more expensive than normal (e.g., it will cause at least some of it to be fetched from a remote store). This flag is reported by filesystems during directory enumerations.

ShareMode may contain zero or more of the following share mode flags:

FILESYS_SHARE_READ0x00000001Enables subsequent open operations on a file or device to request read access.

Enables subsequent open operations to request read access; otherwise, no process can open the file or device if it requests read access. If this flag is not specified, but the file or device has been opened for read access, the function fails.

FILESYS_SHARE_WRITE0x00000002Enables subsequent open operations on a file or device to request write access.

Enables subsequent open operations to request write access; otherwise, no process can open the file or device if it requests write access. If this flag is not specified, but the file or device has been opened for write access or has a file mapping with write access, the function fails.

FILESYS_SHARE_DELETE0x00000004Enables subsequent open operations on a file or device to request delete access.

Enables subsequent open operations to request delete access; otherwise, no process can open the file or device if it requests delete access. If this flag is not specified, but the file or device has been opened for delete access, the function fails.

Note: Delete access allows both delete and rename operations.

CreateDisposition may contain one of the following values:

FILE_DISPOSITION_CREATE_NEW0x00000001Creates a new file, only if it does not already exist.

If the specified file exists, the operation fails with an "already exists" error.

FILE_DISPOSITION_CREATE_ALWAYS0x00000002Creates a new file, always.

If the specified file exists and is writable, the system overwrites the file. If the specified file does not exist and is a valid path, a new file is created.

FILE_DISPOSITION_OPEN_EXISTING0x00000003Opens a file, only if it exists

If the specified file does not exist, opening fails.

FILE_DISPOSITION_OPEN_ALWAYS0x00000004Opens a file, always.

If the specified file exists, the operation succeeds. If the specified file does not exist and is a valid path to a writable location, the a file is created.

FILE_DISPOSITION_TRUNCATE_EXISTING0x00000005Opens a file and truncates it so that its size is zero bytes, only if it exists.

If the specified file does not exist, the operation fails with a "file not found" error.

Options contains the flags that are described in the CreateOptions parameter of the Native API's ZwCreateFile function. Most of those flags correspond to flags passed in the FlagsAndAttributes parameter of the Windows API's CreateFile function, but some flags are specific to Native API. If you need those flags, check both functions' descriptions.

Please refer to Microsoft's documentation for detailed information about these constants.

To determine whether the request is for a file or a directory, compare Attributes against the FILE_SYS_ATTR_DIRECTORY constant, as follows: // Check whether the request is for a file or a directory. bool isDirectory = Attributes & FILE_SYS_ATTR_DIRECTORY == FILE_SYS_ATTR_DIRECTORY; FILE_SYS_ATTR_DIRECTORY will be present only if it was specified by the calling process; its presence or absence does not indicate the real presence of the attribute on the file or directory on disk.

To determine whether a file will be deleted when its last handle is closed, compare Options against the Windows API's FILE_FLAG_DELETE_ON_CLOSE constant, as follows: // Check whether the file will be deleted on close. bool deleteOnClose = Options & FILE_FLAG_DELETE_ON_CLOSE == FILE_FLAG_DELETE_ON_CLOSE;

Note: Files can be deleted in different ways, so do not use this check to take actions related to tracking file deletion operations. Instead, use the events related to file deletion.

To prevent a file or directory from being opened, set the ResultCode parameter to a non-zero value (typically ERROR_ACCESS_DENIED (5)).

When a file or directory is created using the CreateFile() Windows API function, a caller can specify the security descriptor with the security information. This security information should be applied to a newly created file or directory. The component passes this security information in the SecurityInformation and SecurityDescriptor parameters, when the PassSecurityInFileOpenEvents configuration setting is enabled. If this configuration setting is omitted, the corresponding parameters are empty.

The SecurityInformation parameter reflects which pieces of security information, of those present in SecurityDescriptor, are valid and should have been applied. Please refer to Microsoft's SECURITY_INFORMATION data type documentation for more information about possible values.

The SecurityDescriptor parameter points to a memory buffer that contains the security information. The Length parameter reflects the length of this data, in bytes. Please see the Buffer Parameters topic for more information on how to work with memory buffer event parameters.

The data are formatted as a SECURITY_DESCRIPTOR structure in self-relative format; please refer to the Microsoft's documentation for more information.

If an application needs to alter the security information, it can do this by placing up to Length bytes of information into the SecurityDescriptor buffer.

Note: Changing the security data is possible only when the PassSecurityInFileOpenEvents configuration setting is enabled.

If the capacity reflected by the Length parameter is not enough to accommodate the security information, set LengthNeeded to the number of bytes necessary to hold the data, and return the ERROR_INSUFFICIENT_BUFFER error code via ResultCode.

The ProcessRequest parameter controls whether the request is sent onward for further processing by subsequent filter drivers and the filesystem; it is true by default.

If the Options contains the FILE_FLAG_DELETE_ON_CLOSE flag, the BeforeCanFileBeDeleted event will fire before this event.

If the file is opened with extended attributes passed in the request, the BeforeSetEa event will fire after this event.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

BeforeQueryEa Event (CBFilter Component)

This event fires before information about extended attributes of a file is retrieved.

Syntax

public event OnBeforeQueryEaHandler OnBeforeQueryEa;

public delegate void OnBeforeQueryEaHandler(object sender, CbfilterBeforeQueryEaEventArgs e);

public class CbfilterBeforeQueryEaEventArgs : EventArgs {
  public string FileName { get; }
  public IntPtr Buffer { get; }
  public int BufferLength { get; }
  public bool ReturnSingleEntry { get; set; }
  public IntPtr EaList { get; }
  public int EaListLength { get; set; }
  public int EaIndex { get; set; }
  public bool RestartScan { get; set; }
  public int LengthReturned { get; set; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public bool ProcessRequest { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnBeforeQueryEa As OnBeforeQueryEaHandler

Public Delegate Sub OnBeforeQueryEaHandler(sender As Object, e As CbfilterBeforeQueryEaEventArgs)

Public Class CbfilterBeforeQueryEaEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public ReadOnly Property Buffer As IntPtr
  Public ReadOnly Property BufferLength As Integer
  Public Property ReturnSingleEntry As Boolean
  Public ReadOnly Property EaList As IntPtr
  Public Property EaListLength As Integer
  Public Property EaIndex As Integer
  Public Property RestartScan As Boolean
  Public Property LengthReturned As Integer
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ProcessRequest As Boolean
  Public Property ResultCode As Integer
End Class

Remarks

This event fires before information about extended attributes of the file specified by FileName is retrieved using the FltQueryEaFile function of the system API.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_BEFORE_QUERY_EA flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The Buffer parameter points to a memory buffer, into which, if the request is successful, the filesystem will place the requested information. The data in the buffer are formatted as a FILE_FULL_EA_INFORMATION structure; please refer to the Microsoft's documentation for more information. The Length parameter reflects the length of this buffer, in bytes. Please see the Buffer Parameters topic for more information on how to work with memory buffer event parameters.

ReturnSingleEntry specifies that the filesystem had to return only the first entry it has found.

EaList is an optional parameter that points to a caller-supplied memory buffer specifying the extended attributes to be queried. The data in the buffer are formatted as a FILE_GET_EA_INFORMATION structure; please refer to the Microsoft's documentation for more information. The EaListLength parameter reflects the length of this data, in bytes. If the caller of the FltQueryEaFile function did not specify any value, it will contain 0. The list may be modified by an event handler, if needed, provided that the size of the new or modified data does not exceed the value of the EaListLength parameter.

EaIndex is an optional parameter that specifies the starting index of the attribute, information about which is requested. This parameter is ignored by the filesystem if EaList points to a nonempty list. If the caller of the FltQueryEaFile function did not specify any value, the parameter will contain -1.

The RestartScan parameter instructs the filesystem to restart enumeration of extended attributes from the first entry. If the parameter is false, retrieval of the extended attributes is resumed by the filesystem after a previous request. The parameter may be modified by an event handler if needed.

LengthReturned is an optional parameter that contains the size, in bytes, of the information, returned in the Buffer.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information.

The ProcessRequest parameter controls whether the request is sent onward for further processing by subsequent filter drivers and the filesystem; it is true by default.

Applications may use this event to modify the request's data before it continues onward, or to handle the request entirely (preventing it from continuing onward). In these cases, applications must do the following:

  1. Copy no more than BufferLength bytes into Buffer.
  2. Update the LengthReturned parameter's value afterward so that it correctly reflects the amount of data in Buffer.
  3. If the request has been handled and should not continue onward, set ProcessRequest to false.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

BeforeQueryFileInfo Event (CBFilter Component)

This event fires before information about a file or directory is retrieved.

Syntax

public event OnBeforeQueryFileInfoHandler OnBeforeQueryFileInfo;

public delegate void OnBeforeQueryFileInfoHandler(object sender, CbfilterBeforeQueryFileInfoEventArgs e);

public class CbfilterBeforeQueryFileInfoEventArgs : EventArgs {
  public string FileName { get; }
  public int FileInformationClass { get; }
  public IntPtr Buffer { get; }
  public int BufferLength { get; }
  public int ValidBytes { get; set; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public bool ProcessRequest { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnBeforeQueryFileInfo As OnBeforeQueryFileInfoHandler

Public Delegate Sub OnBeforeQueryFileInfoHandler(sender As Object, e As CbfilterBeforeQueryFileInfoEventArgs)

Public Class CbfilterBeforeQueryFileInfoEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public ReadOnly Property FileInformationClass As Integer
  Public ReadOnly Property Buffer As IntPtr
  Public ReadOnly Property BufferLength As Integer
  Public Property ValidBytes As Integer
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ProcessRequest As Boolean
  Public Property ResultCode As Integer
End Class

Remarks

This event fires before information about the file or directory specified by FileName is retrieved; This event typically fires in response to the Windows API's NtQueryInformationFile function.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_BEFORE_QUERY_FILE_INFO flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The FileInformationClass parameter indicates what kind of file information is requested. Please refer to the NtQueryInformationFile function's documentation for more information about possible values.

The Buffer parameter points to a memory buffer that receives the requested file information. The BufferLength and ValidBytes parameters reflect the capacity of Buffer and the length of the data it contains (respectively), in bytes; ValidBytes may be less than BufferLength. Please see the Buffer Parameters topic for more information on how to work with memory buffer event parameters.

The format of the data is determined by the specified FileInformationClass; please refer to the NtQueryInformationFile function's documentation for more information.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information.

The ProcessRequest parameter controls whether the request is sent onward for further processing by subsequent filter drivers and the filesystem; it is true by default.

Applications may use this event to modify the request's data before it continues onward, or to handle the request entirely (preventing it from continuing onward). In these cases, applications must do the following:

  1. Copy no more than BufferLength bytes into Buffer.
  2. Update the ValidBytes parameter's value afterward so that it correctly reflects the amount of data in Buffer.
  3. If the request has been handled and should not continue onward, set ProcessRequest to false.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

BeforeReadFile Event (CBFilter Component)

This event fires before data are read from a file.

Syntax

public event OnBeforeReadFileHandler OnBeforeReadFile;

public delegate void OnBeforeReadFileHandler(object sender, CbfilterBeforeReadFileEventArgs e);

public class CbfilterBeforeReadFileEventArgs : EventArgs {
  public string FileName { get; }
  public long Position { get; set; }
  public IntPtr Buffer { get; }
  public int BufferLength { get; }
  public int BytesToRead { get; set; }
  public int Reserved { get; set; }
  public int Direction { get; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public bool ProcessRequest { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnBeforeReadFile As OnBeforeReadFileHandler

Public Delegate Sub OnBeforeReadFileHandler(sender As Object, e As CbfilterBeforeReadFileEventArgs)

Public Class CbfilterBeforeReadFileEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public Property Position As Long
  Public ReadOnly Property Buffer As IntPtr
  Public ReadOnly Property BufferLength As Integer
  Public Property BytesToRead As Integer
  Public Property Reserved As Integer
  Public ReadOnly Property Direction As Integer
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ProcessRequest As Boolean
  Public Property ResultCode As Integer
End Class

Remarks

This event fires before data are read from the file specified by FileName.

Applications that intend to modify a file's data after it is read may use this event to modify the request's parameters, if necessary (e.g., to ensure that the correct data are read from the file and made available for postprocessing during the AfterReadFile event). Applications may also use this event to block the request entirely by returning an appropriate error code (e.g., ACCESS_DENIED) via ResultCode.

Alternatively, applications may use this event to handle the underlying request, in which case they must do the following:

  1. Enable the ModifiableReadWriteBuffers configuration setting (i.e., before this event fires).
  2. Copy no more than BufferLength bytes into Buffer.
  3. Update the BytesToRead parameter's value afterward so that it correctly reflects the amount of data in Buffer.
  4. Set ProcessRequest to false to indicate that the request has been handled and should not continue onward.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_BEFORE_READ flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The Position parameter specifies the byte offset in the file at which reading should start.

The Buffer parameter points to a memory buffer that receives the data read from the file. The BufferLength parameter reflects the capacity of Buffer, in bytes. Please see the Buffer Parameters topic for more information on how to work with memory buffer event parameters.

The BytesToRead parameter's initial value reflects how many bytes should be read from the file (i.e., how many bytes the requestor expects will be read). This parameter's value may be changed (for either of the reasons discussed above), but it must not exceed BufferLength.

Note: However, reading more or less data than requested is not expected behavior and likely will cause the requestor to misbehave. Applications that change BytesToRead, for any reason, should use the AfterReadFile event to "cover up" such behavior; please refer to its documentation for more information.

The Direction parameter indicates the request direction; please refer to the Cached and Non-Cached Requests topic for more information. Possible values are as follows:

FS_REQUEST_DIR_USER_NONCACHED0Operations performed in the user mode application <--> filesystem direction.
FS_REQUEST_DIR_USER_CACHED1Operations performed in the user mode application <--> system cache direction.
FS_REQUEST_DIR_SYSTEM_NONCACHED2Operations performed in the system cache <--> filesystem direction.
FS_REQUEST_DIR_SYSTEM_CACHED3Operations performed in the system component <--> system cache direction.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information. (If the system's cache manager or memory manager initiated the operation, HandleContext may be absent, in which case it will be IntPtr.Zero.)

The ProcessRequest parameter controls whether the request is sent onward for further processing by subsequent filter drivers and the filesystem; it is true by default.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

BeforeRenameOrMoveFile Event (CBFilter Component)

This event fires before a file or directory is renamed or moved.

Syntax

public event OnBeforeRenameOrMoveFileHandler OnBeforeRenameOrMoveFile;

public delegate void OnBeforeRenameOrMoveFileHandler(object sender, CbfilterBeforeRenameOrMoveFileEventArgs e);

public class CbfilterBeforeRenameOrMoveFileEventArgs : EventArgs {
  public string FileName { get; }
  public string NewFileName { get; }
  public bool ReplaceIfExists { get; set; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public bool ProcessRequest { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnBeforeRenameOrMoveFile As OnBeforeRenameOrMoveFileHandler

Public Delegate Sub OnBeforeRenameOrMoveFileHandler(sender As Object, e As CbfilterBeforeRenameOrMoveFileEventArgs)

Public Class CbfilterBeforeRenameOrMoveFileEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public ReadOnly Property NewFileName As String
  Public Property ReplaceIfExists As Boolean
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ProcessRequest As Boolean
  Public Property ResultCode As Integer
End Class

Remarks

This event fires before the file or directory specified by FileName is renamed or moved to NewFileName.

Applications may use this event to modify the request's parameters, or to block the request entirely. To do the latter, set ProcessRequest to false.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_BEFORE_RENAME flag. A rule's mask is matched against both previous and new filenames, and the event will fire when either of the names matches the mask.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The ReplaceIfExists parameter specifies what to do if a file with the specified NewFileName already exists. If this parameter is true, the existing file will be overwritten by the file being renamed/moved; if this parameter is false, the operation will fail.

Note: Windows only allows files to be overwritten; if the destination is an existing directory, the request will be denied regardless of this parameter's value.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information.

The ProcessRequest parameter controls whether the request is sent onward for further processing by subsequent filter drivers and the filesystem; it is true by default.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

BeforeSetAllocationSize Event (CBFilter Component)

This event fires before a file's allocation size is changed.

Syntax

public event OnBeforeSetAllocationSizeHandler OnBeforeSetAllocationSize;

public delegate void OnBeforeSetAllocationSizeHandler(object sender, CbfilterBeforeSetAllocationSizeEventArgs e);

public class CbfilterBeforeSetAllocationSizeEventArgs : EventArgs {
  public string FileName { get; }
  public long AllocationSize { get; set; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public bool ProcessRequest { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnBeforeSetAllocationSize As OnBeforeSetAllocationSizeHandler

Public Delegate Sub OnBeforeSetAllocationSizeHandler(sender As Object, e As CbfilterBeforeSetAllocationSizeEventArgs)

Public Class CbfilterBeforeSetAllocationSizeEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public Property AllocationSize As Long
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ProcessRequest As Boolean
  Public Property ResultCode As Integer
End Class

Remarks

This event fires before the allocation size of the file specified by FileName is changed.

Applications may use this event to modify the request's parameters.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_BEFORE_SET_SIZES flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The AllocationSize parameter specifies the new allocation size, in bytes. A file's allocation size is typically larger than its actual size because filesystem operations often reserve space on disk before writing additional data to a file. Applications may track such situations and avoid reallocating disk space where possible to improve performance.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information. (If the system's cache manager or memory manager initiated the operation, HandleContext may be absent, in which case it will be IntPtr.Zero.)

The ProcessRequest parameter controls whether the request is sent onward for further processing by subsequent filter drivers and the filesystem; it is true by default.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

BeforeSetEa Event (CBFilter Component)

This event fires before extended attributes of a file are changed.

Syntax

public event OnBeforeSetEaHandler OnBeforeSetEa;

public delegate void OnBeforeSetEaHandler(object sender, CbfilterBeforeSetEaEventArgs e);

public class CbfilterBeforeSetEaEventArgs : EventArgs {
  public string FileName { get; }
  public IntPtr Buffer { get; }
  public int BufferLength { get; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public bool ProcessRequest { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnBeforeSetEa As OnBeforeSetEaHandler

Public Delegate Sub OnBeforeSetEaHandler(sender As Object, e As CbfilterBeforeSetEaEventArgs)

Public Class CbfilterBeforeSetEaEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public ReadOnly Property Buffer As IntPtr
  Public ReadOnly Property BufferLength As Integer
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ProcessRequest As Boolean
  Public Property ResultCode As Integer
End Class

Remarks

This event fires before extended attributes are changed for the file specified by FileName.

If the file is created or opened with extended attributes passed in the request, this event will fire shortly after the BeforeCreateFile or BeforeOpenFile event.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_BEFORE_SET_EA flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The Buffer parameter points to a memory buffer that specifies the extended attribute information. The buffer referenced by the Buffer parameter may be modified when needed if the request is to be passed further to other filters and the filesystem driver. The Length parameter reflects the length of this buffer, in bytes. Please see the Buffer Parameters topic for more information on how to work with memory buffer event parameters.

The data are formatted as a FILE_FULL_EA_INFORMATION structure; please refer to Microsoft's documentation for more information.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information.

The ProcessRequest parameter controls whether the request is sent onward for further processing by subsequent filter drivers and the filesystem; it is true by default.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

BeforeSetFileAttributes Event (CBFilter Component)

This event fires before a file or directory's attributes or times are changed.

Syntax

public event OnBeforeSetFileAttributesHandler OnBeforeSetFileAttributes;

public delegate void OnBeforeSetFileAttributesHandler(object sender, CbfilterBeforeSetFileAttributesEventArgs e);

public class CbfilterBeforeSetFileAttributesEventArgs : EventArgs {
  public string FileName { get; }
  public DateTime CreationTime { get; set; }
  public DateTime LastAccessTime { get; set; }
  public DateTime LastWriteTime { get; set; }
  public DateTime ChangeTime { get; set; }
  public int Attributes { get; set; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public bool ProcessRequest { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnBeforeSetFileAttributes As OnBeforeSetFileAttributesHandler

Public Delegate Sub OnBeforeSetFileAttributesHandler(sender As Object, e As CbfilterBeforeSetFileAttributesEventArgs)

Public Class CbfilterBeforeSetFileAttributesEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public Property CreationTime As DateTime
  Public Property LastAccessTime As DateTime
  Public Property LastWriteTime As DateTime
  Public Property ChangeTime As DateTime
  Public Property Attributes As Integer
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ProcessRequest As Boolean
  Public Property ResultCode As Integer
End Class

Remarks

This event fires before the attributes or times of a file or directory specified by FileName are changed.

Applications may use this event to modify the request's parameters.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_BEFORE_SET_ATTRIBUTES flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The CreationTime, LastAccessTime, LastWriteTime, and ChangeTime parameters specify the new time values, specified in UTC. A value of January 1, 1601 00:00:00 UTC indicates that the corresponding time value is not included in the request.

The Attributes parameter specifies the new attributes; please refer to Microsoft's File Attribute Constants article for attribute descriptions.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information.

The ProcessRequest parameter controls whether the request is sent onward for further processing by subsequent filter drivers and the filesystem; it is true by default.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

BeforeSetFileInfo Event (CBFilter Component)

This event fires before information about a file or directory is changed.

Syntax

public event OnBeforeSetFileInfoHandler OnBeforeSetFileInfo;

public delegate void OnBeforeSetFileInfoHandler(object sender, CbfilterBeforeSetFileInfoEventArgs e);

public class CbfilterBeforeSetFileInfoEventArgs : EventArgs {
  public string FileName { get; }
  public int FileInformationClass { get; }
  public IntPtr Buffer { get; }
  public int BufferLength { get; }
  public int ValidBytes { get; set; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public bool ProcessRequest { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnBeforeSetFileInfo As OnBeforeSetFileInfoHandler

Public Delegate Sub OnBeforeSetFileInfoHandler(sender As Object, e As CbfilterBeforeSetFileInfoEventArgs)

Public Class CbfilterBeforeSetFileInfoEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public ReadOnly Property FileInformationClass As Integer
  Public ReadOnly Property Buffer As IntPtr
  Public ReadOnly Property BufferLength As Integer
  Public Property ValidBytes As Integer
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ProcessRequest As Boolean
  Public Property ResultCode As Integer
End Class

Remarks

This event fires before information about the file or directory specified by FileName is changed; This event typically fires in response to the Windows API's NtSetInformationFile function.

Applications may use this event to modify the request's data before it continues onward, in which case they must do the following:

  1. Copy no more than BufferLength bytes into Buffer.
  2. Update the ValidBytes parameter's value afterward so that it correctly reflects the amount of data in Buffer.

Alternatively, applications may use this event to handle the underlying request, preventing it from continuing onward, by setting ProcessRequest to false.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_BEFORE_SET_FILE_INFO flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The FileInformationClass parameter indicates what kind of file information is to be changed. Please refer to the NtSetInformationFile function's documentation for more information about possible values.

The Buffer parameter points to a memory buffer that specifies the new file information. The BufferLength and ValidBytes parameters reflect the capacity of Buffer and the length of the data it contains, respectively, in bytes; ValidBytes may be less than BufferLength. Please see the Buffer Parameters topic for more information on how to work with memory buffer event parameters.

The format of the data is determined by the specified FileInformationClass; please refer to the NtSetInformationFile function's documentation for more information.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information.

The ProcessRequest parameter controls whether the request is sent onward for further processing by subsequent filter drivers and the filesystem; it is true by default.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

BeforeSetFileSecurity Event (CBFilter Component)

This event fires before a file or directory's security attributes are changed.

Syntax

public event OnBeforeSetFileSecurityHandler OnBeforeSetFileSecurity;

public delegate void OnBeforeSetFileSecurityHandler(object sender, CbfilterBeforeSetFileSecurityEventArgs e);

public class CbfilterBeforeSetFileSecurityEventArgs : EventArgs {
  public string FileName { get; }
  public int SecurityInformation { get; }
  public IntPtr SecurityDescriptor { get; }
  public int Length { get; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public bool ProcessRequest { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnBeforeSetFileSecurity As OnBeforeSetFileSecurityHandler

Public Delegate Sub OnBeforeSetFileSecurityHandler(sender As Object, e As CbfilterBeforeSetFileSecurityEventArgs)

Public Class CbfilterBeforeSetFileSecurityEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public ReadOnly Property SecurityInformation As Integer
  Public ReadOnly Property SecurityDescriptor As IntPtr
  Public ReadOnly Property Length As Integer
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ProcessRequest As Boolean
  Public Property ResultCode As Integer
End Class

Remarks

This event fires before security attributes are changed for the file or directory specified by FileName.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_BEFORE_SET_SECURITY flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The SecurityInformation parameter reflects which pieces of security information, of those present in SecurityDescriptor, will be set. Please refer to Microsoft's SECURITY_INFORMATION data-type documentation for more information about possible values.

The SecurityDescriptor parameter points to a memory buffer that specifies the new security information. The buffer referenced by the SecurityDescriptor parameter may be modified when needed if the request is to be passed further to other filters and the filesystem driver. The Length parameter reflects the length of this data, in bytes. Please see the Buffer Parameters topic for more information on how to work with memory buffer event parameters.

The data are formatted as a SECURITY_DESCRIPTOR structure in self-relative format; please refer to the Microsoft's documentation for more information.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information.

The ProcessRequest parameter controls whether the request is sent onward for further processing by subsequent filter drivers and the filesystem; it is true by default.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

BeforeSetFileSize Event (CBFilter Component)

This event fires before a file is resized.

Syntax

public event OnBeforeSetFileSizeHandler OnBeforeSetFileSize;

public delegate void OnBeforeSetFileSizeHandler(object sender, CbfilterBeforeSetFileSizeEventArgs e);

public class CbfilterBeforeSetFileSizeEventArgs : EventArgs {
  public string FileName { get; }
  public long Size { get; set; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public bool ProcessRequest { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnBeforeSetFileSize As OnBeforeSetFileSizeHandler

Public Delegate Sub OnBeforeSetFileSizeHandler(sender As Object, e As CbfilterBeforeSetFileSizeEventArgs)

Public Class CbfilterBeforeSetFileSizeEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public Property Size As Long
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ProcessRequest As Boolean
  Public Property ResultCode As Integer
End Class

Remarks

This event fires before the file specified by FileName is resized, whether explicitly (e.g., truncation) or implicitly (i.e., as data are appended).

Applications may use this event to modify the request's parameters.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_BEFORE_SET_SIZES flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The Size parameter specifies the new file size, in bytes.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information. (If the system's cache manager or memory manager initiated the operation, HandleContext may be absent, in which case it will be IntPtr.Zero.)

The ProcessRequest parameter controls whether the request is sent onward for further processing by subsequent filter drivers and the filesystem; it is true by default.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

BeforeSetReparsePoint Event (CBFilter Component)

This event fires when the OS wants to create or update a reparse point on a file or directory.

Syntax

public event OnBeforeSetReparsePointHandler OnBeforeSetReparsePoint;

public delegate void OnBeforeSetReparsePointHandler(object sender, CbfilterBeforeSetReparsePointEventArgs e);

public class CbfilterBeforeSetReparsePointEventArgs : EventArgs {
  public string FileName { get; }
  public long ReparseTag { get; }
  public IntPtr ReparseBuffer { get; }
  public int BufferLength { get; }
  public int DataLength { get; set; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public bool ProcessRequest { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnBeforeSetReparsePoint As OnBeforeSetReparsePointHandler

Public Delegate Sub OnBeforeSetReparsePointHandler(sender As Object, e As CbfilterBeforeSetReparsePointEventArgs)

Public Class CbfilterBeforeSetReparsePointEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public ReadOnly Property ReparseTag As Long
  Public ReadOnly Property ReparseBuffer As IntPtr
  Public ReadOnly Property BufferLength As Integer
  Public Property DataLength As Integer
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ProcessRequest As Boolean
  Public Property ResultCode As Integer
End Class

Remarks

This event fires before the OS creates or updates a reparse point on a file or directory specified by FileName.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_BEFORE_SET_REPARSE_POINT flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The ReparseTag is the reparse tag, which is the value the system uses to identify the format of the reparse point data. This value is also present in the ReparseBuffer data; for convenience, the component extracts it and provides it separately. If the event handler needs to change the reparse tag, it may do so in ReparseBuffer.

The ReparseBuffer parameter points to a memory buffer that specifies the new reparse point information. The buffer referenced by the ReparseBuffer parameter may be modified when needed if the request is to be passed further to other filters and the filesystem driver. The DataLength parameter initially reflects the length of the data contained in the buffer, in bytes. If the event handler updates the data in the ReparseBuffer, it should adjust DataLength to the size of the new data, placed to the buffer. Please see the Buffer Parameters topic for more information on how to work with memory buffer event parameters.

Please refer to the Reparse Points topic for more information.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information.

The ProcessRequest parameter controls whether the request is sent onward for further processing by subsequent filter drivers and the filesystem; it is true by default.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

BeforeUnlockAll Event (CBFilter Component)

This event fires before all locked byte ranges in a file are unlocked.

Syntax

public event OnBeforeUnlockAllHandler OnBeforeUnlockAll;

public delegate void OnBeforeUnlockAllHandler(object sender, CbfilterBeforeUnlockAllEventArgs e);

public class CbfilterBeforeUnlockAllEventArgs : EventArgs {
  public string FileName { get; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public bool ProcessRequest { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnBeforeUnlockAll As OnBeforeUnlockAllHandler

Public Delegate Sub OnBeforeUnlockAllHandler(sender As Object, e As CbfilterBeforeUnlockAllEventArgs)

Public Class CbfilterBeforeUnlockAllEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ProcessRequest As Boolean
  Public Property ResultCode As Integer
End Class

Remarks

This event fires before all locked byte ranges in the file specified by FileName are unlocked.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_BEFORE_LOCK_CONTROL flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information.

The ProcessRequest parameter controls whether the request is sent onward for further processing by subsequent filter drivers and the filesystem; it is true by default.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

BeforeUnlockAllByKey Event (CBFilter Component)

This event fires before all locked byte ranges in a file, associated with a particular key, are unlocked.

Syntax

public event OnBeforeUnlockAllByKeyHandler OnBeforeUnlockAllByKey;

public delegate void OnBeforeUnlockAllByKeyHandler(object sender, CbfilterBeforeUnlockAllByKeyEventArgs e);

public class CbfilterBeforeUnlockAllByKeyEventArgs : EventArgs {
  public string FileName { get; }
  public long Key { get; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public bool ProcessRequest { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnBeforeUnlockAllByKey As OnBeforeUnlockAllByKeyHandler

Public Delegate Sub OnBeforeUnlockAllByKeyHandler(sender As Object, e As CbfilterBeforeUnlockAllByKeyEventArgs)

Public Class CbfilterBeforeUnlockAllByKeyEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public ReadOnly Property Key As Long
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ProcessRequest As Boolean
  Public Property ResultCode As Integer
End Class

Remarks

This event fires before all locked byte ranges in the file specified by FileName, and associated with the specified Key, are unlocked.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_BEFORE_LOCK_CONTROL flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The Key parameter contains the key value specified when the byte ranges were locked. Please refer to the BeforeLock event's documentation for more information.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information.

The ProcessRequest parameter controls whether the request is sent onward for further processing by subsequent filter drivers and the filesystem; it is true by default.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

BeforeUnlockSingle Event (CBFilter Component)

This event fires before a particular locked byte range in a file is unlocked.

Syntax

public event OnBeforeUnlockSingleHandler OnBeforeUnlockSingle;

public delegate void OnBeforeUnlockSingleHandler(object sender, CbfilterBeforeUnlockSingleEventArgs e);

public class CbfilterBeforeUnlockSingleEventArgs : EventArgs {
  public string FileName { get; }
  public long Offset { get; set; }
  public long Length { get; set; }
  public long Key { get; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public bool ProcessRequest { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnBeforeUnlockSingle As OnBeforeUnlockSingleHandler

Public Delegate Sub OnBeforeUnlockSingleHandler(sender As Object, e As CbfilterBeforeUnlockSingleEventArgs)

Public Class CbfilterBeforeUnlockSingleEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public Property Offset As Long
  Public Property Length As Long
  Public ReadOnly Property Key As Long
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ProcessRequest As Boolean
  Public Property ResultCode As Integer
End Class

Remarks

This event fires before a particular locked byte range in the file specified by FileName is unlocked.

Applications may use this event to modify the request's parameters.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_BEFORE_LOCK_CONTROL flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The Offset, Length, and Key parameters contain the starting byte offset, length, and key values, respectively, specified when the byte range was locked. Please refer to the BeforeLock event's documentation for more information.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information.

The ProcessRequest parameter controls whether the request is sent onward for further processing by subsequent filter drivers and the filesystem; it is true by default.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

BeforeWriteFile Event (CBFilter Component)

This event fires before data are written to a file.

Syntax

public event OnBeforeWriteFileHandler OnBeforeWriteFile;

public delegate void OnBeforeWriteFileHandler(object sender, CbfilterBeforeWriteFileEventArgs e);

public class CbfilterBeforeWriteFileEventArgs : EventArgs {
  public string FileName { get; }
  public long Position { get; set; }
  public IntPtr Buffer { get; }
  public int BufferLength { get; }
  public int BytesToWrite { get; set; }
  public int Reserved { get; set; }
  public int Direction { get; }
  public IntPtr FileContext { get; set; }
  public IntPtr HandleContext { get; set; }
  public bool ProcessRequest { get; set; }
  public int ResultCode { get; set; }
}
Public Event OnBeforeWriteFile As OnBeforeWriteFileHandler

Public Delegate Sub OnBeforeWriteFileHandler(sender As Object, e As CbfilterBeforeWriteFileEventArgs)

Public Class CbfilterBeforeWriteFileEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public Property Position As Long
  Public ReadOnly Property Buffer As IntPtr
  Public ReadOnly Property BufferLength As Integer
  Public Property BytesToWrite As Integer
  Public Property Reserved As Integer
  Public ReadOnly Property Direction As Integer
  Public Property FileContext As IntPtr
  Public Property HandleContext As IntPtr
  Public Property ProcessRequest As Boolean
  Public Property ResultCode As Integer
End Class

Remarks

This event fires before data are written to the file specified by FileName.

Applications may use this event to modify the request's parameters or data. Applications that choose to modify the request's data must do the following:

  1. Enable the ModifiableReadWriteBuffers configuration setting (i.e., before this event fires).
  2. Copy no more than BufferLength bytes into Buffer.
  3. Update the BytesToWrite parameter's value afterward so that it correctly reflects the amount of data in Buffer.

Applications may also use this event to block the request entirely by returning an appropriate error code (e.g., ACCESS_DENIED) via ResultCode.

Alternatively, applications may use this event to handle the underlying request, in which case they must do the following:

  1. Write the data pointed to by Buffer to the desired location (after preprocessing it, if necessary).
  2. Update the BytesToWrite parameter's value afterward so that it correctly reflects the amount of data that were written.
  3. Set ProcessRequest to false to indicate that the request has been handled and should not continue onward.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_CE_BEFORE_WRITE flag.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

The Position parameter specifies the byte offset in the file at which writing should start. A value of -1 means "append to the end of the file".

The Buffer parameter points to a memory buffer that contains the data to write to the file. The BufferLength parameter reflects the capacity of Buffer, in bytes. Please see the Buffer Parameters topic for more information on how to work with memory buffer event parameters.

The BytesToWrite parameter's initial value reflects how many bytes should be written to the file (i.e., how many bytes the requestor expects will be written). This parameter's value may be changed (for either of the reasons discussed above), but it must not exceed BufferLength.

Note: However, writing more or less data than requested is not expected behavior and likely will cause the requestor to misbehave. Applications that change BytesToWrite, for any reason, should use the AfterWriteFile event to "cover up" such behavior; please refer to its documentation for more information.

The Direction parameter indicates the request direction; please refer to the Cached and Non-Cached Requests topic for more information. Possible values are as follows:

FS_REQUEST_DIR_USER_NONCACHED0Operations performed in the user mode application <--> filesystem direction.
FS_REQUEST_DIR_USER_CACHED1Operations performed in the user mode application <--> system cache direction.
FS_REQUEST_DIR_SYSTEM_NONCACHED2Operations performed in the system cache <--> filesystem direction.
FS_REQUEST_DIR_SYSTEM_CACHED3Operations performed in the system component <--> system cache direction.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information. (If the system's cache manager or memory manager initiated the operation, HandleContext may be absent, in which case it will be IntPtr.Zero.)

The ProcessRequest parameter controls whether the request is sent onward for further processing by subsequent filter drivers and the filesystem; it is true by default.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

CleanupContext Event (CBFilter Component)

This event fires when the application-defined data stored in one or more contexts need to be cleaned up.

Syntax

public event OnCleanupContextHandler OnCleanupContext;

public delegate void OnCleanupContextHandler(object sender, CbfilterCleanupContextEventArgs e);

public class CbfilterCleanupContextEventArgs : EventArgs {
  public IntPtr FileContext { get; }
  public IntPtr HandleContext { get; }
  public int ResultCode { get; set; }
}
Public Event OnCleanupContext As OnCleanupContextHandler

Public Delegate Sub OnCleanupContextHandler(sender As Object, e As CbfilterCleanupContextEventArgs)

Public Class CbfilterCleanupContextEventArgs Inherits EventArgs
  Public ReadOnly Property FileContext As IntPtr
  Public ReadOnly Property HandleContext As IntPtr
  Public Property ResultCode As Integer
End Class

Remarks

This event fires after a file or directory is closed, just before any contexts related to it are discarded, giving applications a chance to clean up any information stored in them.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information.

When a handle to some file or directory is closed, this event will fire if the HandleContext associated with that handle is not IntPtr.Zero. When the last handle to the file or directory is closed, this event will fire if the HandleContext associated with that handle or the FileContext associated with that file or directory is not IntPtr.Zero. After this event fires, the applicable contexts are set back to IntPtr.Zero automatically.

Applications that need to know the name of the file or directory this event is firing for should store a copy of that name in the context during an earlier event.

This event is optional; it will fire regardless of whether any filter rules are present, but only if FileContext, HandleContext, or both, are not already IntPtr.Zero. Applications that clean up their contexts (and set them back to IntPtr.Zero) when a file is being closed, or earlier, do not need to handle this event.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

Error Event (CBFilter Component)

This event fires if an unhandled error occurs during an event.

Syntax

public event OnErrorHandler OnError;

public delegate void OnErrorHandler(object sender, CbfilterErrorEventArgs e);

public class CbfilterErrorEventArgs : EventArgs {
  public int ErrorCode { get; }
  public string Description { get; }
}
Public Event OnError As OnErrorHandler

Public Delegate Sub OnErrorHandler(sender As Object, e As CbfilterErrorEventArgs)

Public Class CbfilterErrorEventArgs Inherits EventArgs
  Public ReadOnly Property ErrorCode As Integer
  Public ReadOnly Property Description As String
End Class

Remarks

This event fires if an unhandled error occurs during another event. Developers can use this information to track down unhandled errors in an application's event handlers.

Note: Not everything is possible or allowed in the event handlers. For details, see the Recursive Calls topic.

FilterStart Event (CBFilter Component)

This event fires once the filter has attached and filtering has started.

Syntax

public event OnFilterStartHandler OnFilterStart;

public delegate void OnFilterStartHandler(object sender, CbfilterFilterStartEventArgs e);

public class CbfilterFilterStartEventArgs : EventArgs {
  public int ResultCode { get; set; }
}
Public Event OnFilterStart As OnFilterStartHandler

Public Delegate Sub OnFilterStartHandler(sender As Object, e As CbfilterFilterStartEventArgs)

Public Class CbfilterFilterStartEventArgs Inherits EventArgs
  Public Property ResultCode As Integer
End Class

Remarks

This event fires once the filter has attached and filtering has started; please refer to the StartFilter method for more information.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource is not available or security checks failed), set it to a nonzero value to report an appropriate error. Please see the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

FilterStop Event (CBFilter Component)

This event fires once filtering has stopped and the filter has detached.

Syntax

public event OnFilterStopHandler OnFilterStop;

public delegate void OnFilterStopHandler(object sender, CbfilterFilterStopEventArgs e);

public class CbfilterFilterStopEventArgs : EventArgs {
  public int ResultCode { get; set; }
}
Public Event OnFilterStop As OnFilterStopHandler

Public Delegate Sub OnFilterStopHandler(sender As Object, e As CbfilterFilterStopEventArgs)

Public Class CbfilterFilterStopEventArgs Inherits EventArgs
  Public Property ResultCode As Integer
End Class

Remarks

This event fires once filtering has stopped and the filter has detached.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason, set it to a non-zero value to report an appropriate error.

Note: This event fires after the operation has already completed, so reporting an error will not actually affect the operation itself. Please refer to the Error Reporting and Handling topic for more information.

This event is fired synchronously; please refer to the Event Types topic for more information.

NotifyCanFileBeDeleted Event (CBFilter Component)

This event fires when the OS marks a file or directory for deletion or removes such a mark.

Syntax

public event OnNotifyCanFileBeDeletedHandler OnNotifyCanFileBeDeleted;

public delegate void OnNotifyCanFileBeDeletedHandler(object sender, CbfilterNotifyCanFileBeDeletedEventArgs e);

public class CbfilterNotifyCanFileBeDeletedEventArgs : EventArgs {
  public string FileName { get; }
  public int RequestType { get; }
  public bool CanDelete { get; }
  public int Status { get; }
  public int ResultCode { get; set; }
}
Public Event OnNotifyCanFileBeDeleted As OnNotifyCanFileBeDeletedHandler

Public Delegate Sub OnNotifyCanFileBeDeletedHandler(sender As Object, e As CbfilterNotifyCanFileBeDeletedEventArgs)

Public Class CbfilterNotifyCanFileBeDeletedEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public ReadOnly Property RequestType As Integer
  Public ReadOnly Property CanDelete As Boolean
  Public ReadOnly Property Status As Integer
  Public Property ResultCode As Integer
End Class

Remarks

This event fires when the OS marks the file or directory specified by FileName for deletion or removes such a mark.

Files and directories can be deleted in two ways: (1) a file or directory can be opened with the FILE_FLAG_DELETE_ON_CLOSE flag, or (2) some process may call Windows API's NtSetInformationFile function with FILE_DISPOSITION_INFORMATION or FILE_DISPOSITION_INFORMATION_EX structure as a parameter.

If the file or directory is created or opened with the FILE_FLAG_DELETE_ON_CLOSE flag, this event is fired shortly after the NotifyCreateFile or NotifyOpenFile event.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_NE_CAN_DELETE flag.

The RequestType indicates which kind of system request resulted in firing this event. It can be one of the following:

DEL_REQ_OPEN_FLAG0x1The file or directory is opened with the FILE_FLAG_DELETE_ON_CLOSE flag

DEL_REQ_SET_DISPOSITION0x2The system has sent the IRP_MJ_SET_INFORMATION request with SetFileDisposition structure as a parameter.

This request usually is sent using the NtSetInformationFile() Windows native API function.

The CanDelete parameter reflects whether or not the file or directory can be deleted.

The Status parameter contains an NT status code that indicates the outcome of the operation; 0 indicates success. To convert this value to a Win32 error code, call the NtStatusToWin32Error method.

Note: This event will not fire for failed requests unless the ProcessFailedRequests property is enabled.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason, set it to a non-zero value to report an appropriate error.

Note: This event fires after the operation has already completed, so reporting an error will not actually affect the operation itself. Please refer to the Error Reporting and Handling topic for more information.

This event is fired asynchronously; please refer to the Event Types topic for more information.

NotifyCleanupFile Event (CBFilter Component)

This event fires when a file or directory handle has been closed.

Syntax

public event OnNotifyCleanupFileHandler OnNotifyCleanupFile;

public delegate void OnNotifyCleanupFileHandler(object sender, CbfilterNotifyCleanupFileEventArgs e);

public class CbfilterNotifyCleanupFileEventArgs : EventArgs {
  public string FileName { get; }
  public int ResultCode { get; set; }
}
Public Event OnNotifyCleanupFile As OnNotifyCleanupFileHandler

Public Delegate Sub OnNotifyCleanupFileHandler(sender As Object, e As CbfilterNotifyCleanupFileEventArgs)

Public Class CbfilterNotifyCleanupFileEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public Property ResultCode As Integer
End Class

Remarks

This event fires when a handle to the file or directory specified by FileName has been closed. This event differs from NotifyCloseFile in that NotifyCleanupFile fires when an open handle to the specified file or directory is closed by a process, whereas NotifyCloseFile may be fired much later when the OS itself decides that the file or directory can be formally closed.

Other events may fire for the file or directory in the time between when this event fires and when the NotifyCloseFile event fires. For example, system components, such as the memory manager or cache manager, may cause the NotifyReadFile and NotifyWriteFile events to fire.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_NE_CLEANUP flag.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason, set it to a non-zero value to report an appropriate error.

Note: This event fires after the operation has already completed, so reporting an error will not actually affect the operation itself. Please refer to the Error Reporting and Handling topic for more information.

This event is fired asynchronously; please refer to the Event Types topic for more information.

NotifyCloseFile Event (CBFilter Component)

This event fires when a file or directory has been closed.

Syntax

public event OnNotifyCloseFileHandler OnNotifyCloseFile;

public delegate void OnNotifyCloseFileHandler(object sender, CbfilterNotifyCloseFileEventArgs e);

public class CbfilterNotifyCloseFileEventArgs : EventArgs {
  public string FileName { get; }
  public int ResultCode { get; set; }
}
Public Event OnNotifyCloseFile As OnNotifyCloseFileHandler

Public Delegate Sub OnNotifyCloseFileHandler(sender As Object, e As CbfilterNotifyCloseFileEventArgs)

Public Class CbfilterNotifyCloseFileEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public Property ResultCode As Integer
End Class

Remarks

This event fires when the file or directory specified by FileName has been closed.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_NE_CLOSE flag.

If the file or directory was marked for deletion earlier, the NotifyDeleteFile will fire shortly before this event.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason, set it to a non-zero value to report an appropriate error.

Note: This event fires after the operation has already completed, so reporting an error will not actually affect the operation itself. Please refer to the Error Reporting and Handling topic for more information.

This event is fired asynchronously; please refer to the Event Types topic for more information.

NotifyCreateFile Event (CBFilter Component)

This event fires when a file or directory has been created.

Syntax

public event OnNotifyCreateFileHandler OnNotifyCreateFile;

public delegate void OnNotifyCreateFileHandler(object sender, CbfilterNotifyCreateFileEventArgs e);

public class CbfilterNotifyCreateFileEventArgs : EventArgs {
  public string FileName { get; }
  public int ExistingAttributes { get; }
  public int DesiredAccess { get; }
  public int Attributes { get; }
  public int ShareMode { get; }
  public int Options { get; }
  public int CreateDisposition { get; }
  public IntPtr SecurityDescriptor { get; }
  public int Length { get; }
  public int Status { get; }
  public int ResultCode { get; set; }
}
Public Event OnNotifyCreateFile As OnNotifyCreateFileHandler

Public Delegate Sub OnNotifyCreateFileHandler(sender As Object, e As CbfilterNotifyCreateFileEventArgs)

Public Class CbfilterNotifyCreateFileEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public ReadOnly Property ExistingAttributes As Integer
  Public ReadOnly Property DesiredAccess As Integer
  Public ReadOnly Property Attributes As Integer
  Public ReadOnly Property ShareMode As Integer
  Public ReadOnly Property Options As Integer
  Public ReadOnly Property CreateDisposition As Integer
  Public ReadOnly Property SecurityDescriptor As IntPtr
  Public ReadOnly Property Length As Integer
  Public ReadOnly Property Status As Integer
  Public Property ResultCode As Integer
End Class

Remarks

This event fires when the file or directory specified by FileName has been created. Please refer to the File Create/Open Events topic for more information about how the component determines whether to fire this event or NotifyOpenFile.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_NE_CREATE flag.

Note: Applications must have the FilterOwnRequests configuration setting enabled if they wish to filter their own file/directory creation requests.

When extended rules are used or the AlwaysRequestAttributesOnOpen configuration setting is enabled, the driver requests attributes of the entity from the filesystem and passes them to ExistingAttributes. If the attributes are not requested, this parameter contains 0.

The DesiredAccess, Attributes, ShareMode, and CreateDisposition parameters reflect the values that were passed for the similarly named parameters of the Windows API's CreateFile function (or, more accurately, the values carried by the IRP_MJ_CREATE IRP).

DesiredAccess may contain one or more of the following access flags:

DESIRED_ACCESS_FILE_LIST_DIRECTORY0x00000001For a directory, the right to list the contents of the directory.

DESIRED_ACCESS_FILE_READ_DATA0x00000001For a file object, the right to read the corresponding file data.

For a directory object, the right to read the corresponding directory data.

DESIRED_ACCESS_FILE_ADD_FILE0x00000002For a directory, the right to create a file in the directory.

DESIRED_ACCESS_FILE_WRITE_DATA0x00000002For a file object, the right to write data to the file.

For a directory object, the right to create a file in the directory

DESIRED_ACCESS_FILE_ADD_SUBDIRECTORY0x00000004For a directory, the right to create a subdirectory.

DESIRED_ACCESS_FILE_APPEND_DATA0x00000004For a file object, the right to append data to the file.

(For local files, write operations will not overwrite existing data if this flag is specified without FILE_WRITE_DATA.) For a directory object, the right to create a subdirectory (FILE_ADD_SUBDIRECTORY).

DESIRED_ACCESS_FILE_READ_EA0x00000008The right to read extended file attributes.

DESIRED_ACCESS_FILE_WRITE_EA0x00000010The right to write extended file attributes.

DESIRED_ACCESS_FILE_EXECUTE0x00000020For a native code file, the right to execute the file.

This access right given to scripts may cause the script to be executable, depending on the script interpreter.

DESIRED_ACCESS_FILE_DELETE_CHILD0x00000040For a directory, the right to delete a directory and all the files it contains, including read-only files.

DESIRED_ACCESS_FILE_READ_ATTRIBUTES0x00000080The right to read file attributes.

DESIRED_ACCESS_FILE_WRITE_ATTRIBUTES0x00000100The right to write file attributes.

DESIRED_ACCESS_READ_CONTROL0x00020000The right to read the information in the file or directory object's security descriptor.

This does not include the information in the SACL.

DESIRED_ACCESS_STANDARD_RIGHTS_READ0x00020000Includes READ_CONTROL, which is the right to read the information in the file or directory object's security descriptor.

This does not include the information in the SACL.

DESIRED_ACCESS_STANDARD_RIGHTS_WRITE0x00020000Same as STANDARD_RIGHTS_READ

DESIRED_ACCESS_STANDARD_RIGHTS_EXECUTE0x00020000Same as STANDARD_RIGHTS_READ

DESIRED_ACCESS_SYNCHRONIZE0x00100000The right to use the object for synchronization.

This enables a thread to wait until the object is in the signaled state. Some object types do not support this access right.

DESIRED_ACCESS_FILE_ALL_ACCESS0x001F01FFAll possible access rights for a file.

DESIRED_ACCESS_FILE_GENERIC_READ0x00120089A combinarion of flags that allow reading of the file.

Note: Don't match received values against this flag. Instead, use flags that specify the rights that you want to verify or add/remove.

DESIRED_ACCESS_FILE_GENERIC_WRITE0x00120116A combinarion of flags that allow modifications to the file.

Note: Don't match received values against this flag. Instead, use flags that specify the rights that you want to verify or add/remove.

DESIRED_ACCESS_FILE_GENERIC_EXECUTE0x001200A0A combinarion of flags that allow execution of the file.

Note: Don't match received values against this flag. Instead, use flags that specify the rights that you want to verify or add/remove.

Attributes may contain one or more of the following attributes:

FILE_SYS_ATTR_READ_ONLY0x00000001The file is read-only.

Applications can read the file, but cannot write to it or delete it. This attribute is not honored on directories.

FILE_SYS_ATTR_HIDDEN0x00000002The file or directory is hidden.

The file is not included in an ordinary directory listing.

FILE_SYS_ATTR_SYSTEM0x00000004A file or directory that the operating system uses a part of, or uses exclusively.

FILE_SYS_ATTR_DIRECTORY0x00000010The entry is a directory.

FILE_SYS_ATTR_ARCHIVE0x00000020The entry is an archive file or directory.

Applications typically use this attribute to mark files for backup or removal.

FILE_SYS_ATTR_NORMAL0x00000080A file doesn't have other attributes set.

This attribute is valid only when used alone.

FILE_SYS_ATTR_TEMPORARY0x00000100A file that is being used for temporary storage.

File systems avoid writing data back to mass storage if sufficient cache memory is available, because typically, an application deletes a temporary file after the handle is closed. In that scenario, the system can entirely avoid writing the data. Otherwise, the data are written after the handle is closed.

FILE_SYS_ATTR_SPARSE_FILE0x00000200A file that is a sparse file.

FILE_SYS_ATTR_REPARSE_POINT0x00000400A file that is a reparse point or a symbolic link.

FILE_SYS_ATTR_COMPRESSED0x00000800A file or directory that is compressed.

For a file, all of the data in the file are compressed. For a directory, compression is the default for newly created files and subdirectories. A filesystem implementation can make use of this attribute by setting the SupportCompressedAttribute property to true and then properly handling the GetFileInfo, EnumerateDirectory, and SetFileAttributes events.

FILE_SYS_ATTR_OFFLINE0x00001000The data of a file are not available immediately.

This attribute indicates that the file data are physically moved to offline storage.

FILE_SYS_ATTR_NOT_CONTENT_INDEXED0x00002000The file or directory is not to be indexed by the content indexing service.

FILE_SYS_ATTR_ENCRYPTED0x00004000A file or directory that is encrypted.

For a file, all data streams in the file are encrypted. For a directory, encryption is the default for newly created files and subdirectories.

Note: This flag is used by NTFS and the OS sends undocumented requests to the filesystem based on this flag. The flag should not be used for files in custom filesystem implementations.

FILE_SYS_ATTR_VIRTUAL0x00010000Reserved.

Note: This flag is reserved by the OS and should not be used for files in custom filesystem implementations.

FILE_SYS_ATTR_RECALL_ON_OPEN0x00040000The file or directory has no physical representation on the local system; the item is virtual.

Opening the item will be more expensive than normal (e.g., it will cause at least some of it to be fetched from a remote store). This flag is reported by filesystems during directory enumerations.

ShareMode may contain zero or more of the following share mode flags:

FILESYS_SHARE_READ0x00000001Enables subsequent open operations on a file or device to request read access.

Enables subsequent open operations to request read access; otherwise, no process can open the file or device if it requests read access. If this flag is not specified, but the file or device has been opened for read access, the function fails.

FILESYS_SHARE_WRITE0x00000002Enables subsequent open operations on a file or device to request write access.

Enables subsequent open operations to request write access; otherwise, no process can open the file or device if it requests write access. If this flag is not specified, but the file or device has been opened for write access or has a file mapping with write access, the function fails.

FILESYS_SHARE_DELETE0x00000004Enables subsequent open operations on a file or device to request delete access.

Enables subsequent open operations to request delete access; otherwise, no process can open the file or device if it requests delete access. If this flag is not specified, but the file or device has been opened for delete access, the function fails.

Note: Delete access allows both delete and rename operations.

CreateDisposition may contain one of the following values:

FILE_DISPOSITION_CREATE_NEW0x00000001Creates a new file, only if it does not already exist.

If the specified file exists, the operation fails with an "already exists" error.

FILE_DISPOSITION_CREATE_ALWAYS0x00000002Creates a new file, always.

If the specified file exists and is writable, the system overwrites the file. If the specified file does not exist and is a valid path, a new file is created.

FILE_DISPOSITION_OPEN_EXISTING0x00000003Opens a file, only if it exists

If the specified file does not exist, opening fails.

FILE_DISPOSITION_OPEN_ALWAYS0x00000004Opens a file, always.

If the specified file exists, the operation succeeds. If the specified file does not exist and is a valid path to a writable location, the a file is created.

FILE_DISPOSITION_TRUNCATE_EXISTING0x00000005Opens a file and truncates it so that its size is zero bytes, only if it exists.

If the specified file does not exist, the operation fails with a "file not found" error.

Options contains the flags that are described in the CreateOptions parameter of the native API's ZwCreateFile function. Most of those flags correspond to flags passed in the FlagsAndAttributes parameter of the Windows API's CreateFile function, but some flags are specific to the native API. If you need those flags, check both functions' descriptions.

Please refer to Microsoft's documentation for detailed information about these constants.

To determine whether the request was for a file or a directory, compare Attributes against the FILE_SYS_ATTR_DIRECTORY constant, as follows: // Check whether the request is for a file or a directory. bool isDirectory = Attributes & FILE_SYS_ATTR_DIRECTORY == FILE_SYS_ATTR_DIRECTORY; FILE_SYS_ATTR_DIRECTORY will be present if it was specified by the calling process or if the existing filesystem entry is a directory.

To determine whether a file will be deleted when its last handle is closed, compare Options against the Windows API's FILE_FLAG_DELETE_ON_CLOSE constant, as follows: // Check whether the file will be deleted on close. bool deleteOnClose = Options & FILE_FLAG_DELETE_ON_CLOSE == FILE_FLAG_DELETE_ON_CLOSE; Note: Because files can be deleted in different ways, do not use this check to take actions related to tracking file deletion operations. Instead, use the events related to file deletion.

When a file or directory is created using the CreateFile() Windows API function, a caller can specify the security descriptor with the security information. This security information should be applied to a newly created file or directory. The component passes this security information in the SecurityInformation and SecurityDescriptor parameters, when the PassSecurityInFileOpenEvents configuration setting is enabled. If this configuration setting is omitted, the corresponding parameters are empty.

The SecurityInformation parameter reflects which pieces of security information, of those present in SecurityDescriptor, are valid and should have been applied. Please refer to Microsoft's SECURITY_INFORMATION data type documentation for more information about possible values.

The SecurityDescriptor parameter points to a memory buffer that contains the security information. The Length parameter reflects the length of this data, in bytes. Please see the Buffer Parameters topic for more information on how to work with memory buffer event parameters.

The data are formatted as a SECURITY_DESCRIPTOR structure in self-relative format; please refer to the Microsoft's documentation for more information.

If the Options contains the FILE_FLAG_DELETE_ON_CLOSE flag, the NotifyCanFileBeDeleted event will fire after this event.

If the file is created with extended attributes passed in the request, the NotifySetEa event will fire after this event.

The Status parameter contains an NT status code that indicates the outcome of the operation; 0 indicates success. To convert this value to a Win32 error code, call the NtStatusToWin32Error method.

Note: This event will not fire for failed requests unless the ProcessFailedRequests property is enabled.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason, set it to a non-zero value to report an appropriate error.

Note: This event fires after the operation has already completed, so reporting an error will not actually affect the operation itself. Please refer to the Error Reporting and Handling topic for more information.

This event is fired asynchronously; please refer to the Event Types topic for more information.

NotifyCreateHardLink Event (CBFilter Component)

This event fires when a hard link has been created.

Syntax

Remarks

This event fires when a hard link to the file specified by FileName has been created. Please refer to Microsoft's Hard Links article for more information about hard links.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_NE_CREATE_HARD_LINK flag.

The LinkName parameter reflects the name of the created hard link.

The Status parameter contains an NT status code that indicates the outcome of the operation; 0 indicates success. To convert this value to a Win32 error code, call the NtStatusToWin32Error method.

Note: This event will not fire for failed requests unless the ProcessFailedRequests property is enabled.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason, set it to a non-zero value to report an appropriate error.

Note: This event fires after the operation has already completed, so reporting an error will not actually affect the operation itself. Please refer to the Error Reporting and Handling topic for more information.

This event is fired asynchronously; please refer to the Event Types topic for more information.

NotifyDeleteFile Event (CBFilter Component)

This event fires when a file or directory has been deleted.

Syntax

public event OnNotifyDeleteFileHandler OnNotifyDeleteFile;

public delegate void OnNotifyDeleteFileHandler(object sender, CbfilterNotifyDeleteFileEventArgs e);

public class CbfilterNotifyDeleteFileEventArgs : EventArgs {
  public string FileName { get; }
  public int RequestType { get; }
  public int ResultCode { get; set; }
}
Public Event OnNotifyDeleteFile As OnNotifyDeleteFileHandler

Public Delegate Sub OnNotifyDeleteFileHandler(sender As Object, e As CbfilterNotifyDeleteFileEventArgs)

Public Class CbfilterNotifyDeleteFileEventArgs Inherits EventArgs
  Public ReadOnly Property FileName As String
  Public ReadOnly Property RequestType As Integer
  Public Property ResultCode As Integer
End Class

Remarks

This event fires when the file or directory specified by FileName has been deleted. More specifically, this event is queued for delivery after the final IRP_MJ_CLOSE I/O request packet (IRP) has been processed by the filesystem (i.e., after the last handle to the file or directory is closed and the file or directory is gone) and before NotifyCloseFile is queued.

Applications need to handle this event only if they have added a standard filter rule that includes the FS_NE_DELETE flag.

The RequestType indicates which kind of system req