FltGetDestinationFileNameInformation function

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NTSTATUS FLTAPI FltGetDestinationFileNameInformation(
  PFLT_INSTANCE              Instance,
  PFILE_OBJECT               FileObject,
  HANDLE                     RootDirectory,
  PWSTR                      FileName,
  ULONG                      FileNameLength,
  FLT_FILE_NAME_OPTIONS      NameOptions,
  PFLT_FILE_NAME_INFORMATION *RetFileNameInformation
);

Parameters

Instance

Opaque instance pointer for a minifilter driver instance that is attached to the volume where the file resides.

FileObject

Pointer to the file object for the file. This parameter is required and cannot be NULL.

RootDirectory

For link operations: If the link is to be created in the same directory as the file that is being linked to, or if the FileName parameter contains the full pathname for the link to be created, this parameter is NULL. Otherwise it is a handle for the directory where the link is to be created.

For rename operations: If the file is not being moved to a different directory, or if the FileName parameter contains the full pathname, this parameter is NULL. Otherwise it is a handle for the directory where the file resides after it is renamed.

FileName

Link operations: Pointer to a wide-character string containing the name to be assigned to the newly created link.

Rename operations: Pointer to a wide-character string containing the new name for the file.

FileNameLength

Length, in bytes, of the wide-character string that FileName points to.

NameOptions

FLT_FILE_NAME_OPTIONS value containing flags that specify the format of the name information to be returned, the query method that the Filter Manager is to use, and additional file name flags. This parameter is required and cannot be NULL.

The following are the name format flag values. Only one name format flag can be specified. (Note that FLT_FILE_NAME_SHORT is not a valid flag value for this parameter.)

The following are the query method flag values. Only one query method flag can be specified.

The following are the file name flag values. Any combination of these flags can be specified.

RetFileNameInformation

Pointer to a caller-allocated variable that receives the address of a system-allocated FLT_FILE_NAME_INFORMATION structure containing the file name information. FltGetDestinationFileNameInformation allocates this structure from paged pool. This parameter is required and cannot be NULL.

Return value

FltGetDestinationFileNameInformation returns STATUS_SUCCESS or an appropriate NTSTATUS value such as one of the following:

Remarks

FltGetDestinationFileNameInformation returns the file name information in either normalized or "opened file" format. For more information on these formats, see the FLT_FILE_NAME_INFORMATION structure.

The file object pointer that is passed for the FileObject parameter must be either the FileObject member of the FLT_RELATED_OBJECTS structure for the operation or the Data->Iopb->TargetFileObject pointer for the operation, where Data is the callback data structure for the operation (FLT_CALLBACK_DATA). The file object pointer cannot be the Data->Iopb->Parameters.SetFileInformation.FileObject member, because this field is not used uniformly across file systems.

If the user opened the file by using the file ID but does not have traverse privilege for the entire path, FltGetDestinationFileNameInformation returns only the portion of the path that the user has privilege for.

A rename or hard-link-creation operation can only be performed within a volume and not across volumes. Therefore, such an operation fails if the destination path name contains a mount point that resolves to a volume other than the one where the file resides. For more information about rename operations, see the FILE_RENAME_INFORMATION structure. For more information about hard-link creation operations, see the FILE_LINK_INFORMATION structures.

After a successful call to FltGetDestinationFileNameInformation, the caller is responsible for releasing the pointer returned in the RetFileNameInformation parameter when it is no longer needed by calling FltReleaseFileNameInformation.

The caller must not modify the contents of the structure returned in the RetFileNameInformation parameter, because this structure is cached by the Filter Manager so that all minifilter drivers can use it.

In create, hard-link, and rename operations, file name tunneling can cause the final component in normalized file name information that a minifilter driver retrieves in a preoperation callback routine to be invalidated. If a minifilter driver retrieves normalized file name information in a preoperation callback (PFLT_PRE_OPERATION_CALLBACK) routine by calling a routine such as FltGetDestinationFileNameInformation, it must call FltGetTunneledName from its postoperation callback (PFLT_POST_OPERATION_CALLBACK) routine to retrieve the correct file name information for the file.

For more information about normalized file name information, see FLT_FILE_NAME_INFORMATION.

The following paired operations can cause the file name name to be tunneled:

• delete(name)/create(name)
• delete(name)/rename(source, name)
• rename(name, newname)/create(name)
• rename(name, newname)/rename(source, name)

Requirements