fileinfo.c

windows 2000中的UDF文件系统的驱动程序.只有读的功能,不支持未关闭的盘片.只支持UDF2.0以下版本,不支持VAT格式的UDF.

    return;
}


//
//  Local support routine
//

VOID
UdfQueryInternalInfo (
    IN PIRP_CONTEXT IrpContext,
    IN PFCB Fcb,
    IN OUT PFILE_INTERNAL_INFORMATION Buffer,
    IN OUT PULONG Length
    )

/*++

Routine Description:

    This routine performs the query internal information function for Udfs.

Arguments:

    Fcb - Supplies the Fcb being queried, it has been verified

    Buffer - Supplies a pointer to the buffer where the information is to
        be returned

    Length - Supplies the length of the buffer in bytes, and receives the
        remaining bytes free in the buffer upon return.

Return Value:

    None

--*/

{
    PAGED_CODE();

    //
    //  Index number is the file Id number in the Fcb.
    //

    Buffer->IndexNumber = Fcb->FileId;
    *Length -= sizeof( FILE_INTERNAL_INFORMATION );

    return;
}


//
//  Local support routine
//

VOID
UdfQueryEaInfo (
    IN PIRP_CONTEXT IrpContext,
    IN PFCB Fcb,
    IN OUT PFILE_EA_INFORMATION Buffer,
    IN OUT PULONG Length
    )

/*++

Routine Description:

    This routine performs the query Ea information function for Udfs.

Arguments:

    Fcb - Supplies the Fcb being queried, it has been verified

    Buffer - Supplies a pointer to the buffer where the information is to
        be returned

    Length - Supplies the length of the buffer in bytes, and receives the
        remaining bytes free in the buffer upon return.

Return Value:

    None

--*/

{
    PAGED_CODE();

    //
    //  No Ea's on Udfs volumes.  At least not that our EA support would understand.
    //

    Buffer->EaSize = 0;
    *Length -= sizeof( FILE_EA_INFORMATION );

    return;
}


//
//  Local support routine
//

VOID
UdfQueryPositionInfo (
    IN PIRP_CONTEXT IrpContext,
    IN PFILE_OBJECT FileObject,
    IN OUT PFILE_POSITION_INFORMATION Buffer,
    IN OUT PULONG Length
    )

/*++

Routine Description:

    This routine performs the query position information function for Udfs.

Arguments:

    FileObject - Supplies the File object being queried

    Buffer - Supplies a pointer to the buffer where the information is to
        be returned

    Length - Supplies the length of the buffer in bytes, and receives the
        remaining bytes free in the buffer upon return.

Return Value:

    None

--*/

{
    PAGED_CODE();

    //
    //  Get the current position found in the file object.
    //

    Buffer->CurrentByteOffset = FileObject->CurrentByteOffset;

    //
    //  Update the length and status output variables
    //

    *Length -= sizeof( FILE_POSITION_INFORMATION );

    return;
}


//
//  Local support routine
//

NTSTATUS
UdfQueryNameInfo (
    IN PIRP_CONTEXT IrpContext,
    IN PFILE_OBJECT FileObject,
    IN OUT PFILE_NAME_INFORMATION Buffer,
    IN OUT PULONG Length
    )

/*++

Routine Description:

    This routine performs the query name information function for Udfs.

Arguments:

    FileObject - Supplies the file object containing the name.

    Buffer - Supplies a pointer to the buffer where the information is to
        be returned

    Length - Supplies the length of the buffer in bytes, and receives the
        remaining bytes free in the buffer upon return.

Return Value:

    NTSTATUS - STATUS_BUFFER_OVERFLOW if the entire name can't be copied.

--*/

{
    NTSTATUS Status = STATUS_SUCCESS;
    ULONG LengthToCopy;

    PAGED_CODE();

    ASSERT(*Length >= sizeof(ULONG));
    
    //
    //  Simply copy the name in the file object to the user's buffer.
    //

    //
    //  Place the size of the filename in the user's buffer and reduce the remaining
    //  size to match.
    //

    Buffer->FileNameLength = LengthToCopy = FileObject->FileName.Length;
    *Length -= sizeof(ULONG);

    if (LengthToCopy > *Length) {

        LengthToCopy = *Length;
        Status = STATUS_BUFFER_OVERFLOW;
    }

    RtlCopyMemory( Buffer->FileName, FileObject->FileName.Buffer, LengthToCopy );

    //
    //  Reduce the available bytes by the amount stored into this buffer.  In the overflow
    //  case, this simply drops to zero.  The returned filenamelength will indicate to the
    //  caller how much space is required.
    //

    *Length -= LengthToCopy;

    return Status;
}


//
//  Local support routine
//

NTSTATUS
UdfQueryAlternateNameInfo (
    IN PIRP_CONTEXT IrpContext,
    IN PFCB Fcb,
    IN PCCB Ccb,
    IN OUT PFILE_NAME_INFORMATION Buffer,
    IN OUT PULONG Length
    )

/*++

Routine Description:

    This routine performs the query alternate name information function.
    We lookup the dirent for this file and then check if there is a
    short name.

Arguments:

    Fcb - Supplies the Fcb being queried, it has been verified.

    Ccb - Ccb for this open handle.

    Buffer - Supplies a pointer to the buffer where the information is to
        be returned.

    Length - Supplies the length of the buffer in bytes, and receives the
        remaining bytes free in the buffer upon return.

Return Value:

    NTSTATUS - STATUS_SUCCESS if the whole name would fit into the user buffer,
               STATUS_OBJECT_NAME_NOT_FOUND if we can't return the name,
               STATUS_BUFFER_OVERFLOW otherwise.

--*/

{
    NTSTATUS Status = STATUS_SUCCESS;

    DIR_ENUM_CONTEXT DirContext;

    PLCB Lcb;
    
    PFCB ParentFcb;
    BOOLEAN ReleaseParentFcb = FALSE;

    BOOLEAN CleanupDirContext = FALSE;
    BOOLEAN Result;

    PUNICODE_STRING ShortName;

    UNICODE_STRING LocalShortName;
    WCHAR LocalShortNameBuffer[ BYTE_COUNT_8_DOT_3 / sizeof(WCHAR) ];
    
    PAGED_CODE();

    //
    //  Initialize the buffer length to zero.
    //

    Buffer->FileNameLength = 0;

    //
    //  If there was no associated Lcb then there is no short name.
    //

    Lcb = Ccb->Lcb;
    
    if (Lcb == NULL) {

        return STATUS_OBJECT_NAME_NOT_FOUND;
    }

    //
    //  Use a try-finally to cleanup the structures.
    //

    try {

        if (FlagOn( Lcb->Flags, LCB_FLAG_SHORT_NAME )) {

            //
            //  This caller opened the file by a generated short name, so simply hand it back.
            //

            ShortName = &Lcb->FileName;
        
        } else {

            //
            //  The open occured by a regular name.  Now, if this name is already 8.3 legal then
            //  there is no short name.
            //

            if (UdfIs8dot3Name( IrpContext, Lcb->FileName )) {

                try_leave( Status = STATUS_OBJECT_NAME_NOT_FOUND );
            }

            //
            //  This name has a generated short name.  In order to calculate this name we have to
            //  retrieve the FID for this file, since UDF specifies that a short name is uniquified
            //  with a CRC of the original in-FID byte representation of the filename.
            //
            //  N.B.: if this is a common operation, we may wish to cache the CRC in the Lcb.
            //

            ParentFcb = Lcb->ParentFcb;
            UdfAcquireFileShared( IrpContext, ParentFcb );
            ReleaseParentFcb = TRUE;

            //
            //  Now go find the FID for this filename in the parent.
            //

            UdfInitializeDirContext( IrpContext, &DirContext );
            CleanupDirContext = TRUE;

            Result = UdfFindDirEntry( IrpContext,
                                      ParentFcb,
                                      &Lcb->FileName,
                                      BooleanFlagOn( Lcb->Flags, LCB_FLAG_IGNORE_CASE ),
                                      FALSE,
                                      &DirContext );
            
            //
            //  We should always be able to find this entry, but don't bugcheck because
            //  we screwed this up.
            //
            
            ASSERT( Result );
            
            if (!Result) {
                
                try_leave( Status = STATUS_OBJECT_NAME_NOT_FOUND );
            }

            //
            //  Build the local unicode string to use and fill it in.
            //

            ShortName = &LocalShortName;

            LocalShortName.Buffer = LocalShortNameBuffer;
            LocalShortName.Length = 0;
            LocalShortName.MaximumLength = sizeof( LocalShortNameBuffer );

            UdfGenerate8dot3Name( IrpContext,
                                  &DirContext.CaseObjectName,
                                  ShortName );
        }
        
        //
        //  We now have the short name.  We have left it in Unicode form so copy it directly.
        //

        Buffer->FileNameLength = ShortName->Length;

        if (Buffer->FileNameLength + sizeof( ULONG ) > *Length) {

            Buffer->FileNameLength = *Length - sizeof( ULONG );
            Status = STATUS_BUFFER_OVERFLOW;
        }

        RtlCopyMemory( Buffer->FileName, ShortName->Buffer, Buffer->FileNameLength );

    } finally {

        if (CleanupDirContext) {

            UdfCleanupDirContext( IrpContext, &DirContext );
        }

        if (ReleaseParentFcb) {

            UdfReleaseFile( IrpContext, ParentFcb );
        }
    }

    //
    //  Reduce the available bytes by the amount stored into this buffer.
    //

    if (Status != STATUS_OBJECT_NAME_NOT_FOUND) {

        *Length -= sizeof( ULONG ) + Buffer->FileNameLength;
    }

    return Status;
}


//
//  Local support routine
//

VOID
UdfQueryNetworkInfo (
    IN PIRP_CONTEXT IrpContext,
    IN PFCB Fcb,
    IN PCCB Ccb,
    IN OUT PFILE_NETWORK_OPEN_INFORMATION Buffer,
    IN OUT PULONG Length
    )

/*++

 Description:

    This routine performs the query network open information function for Udfs.

Arguments:

    Fcb - Supplies the Fcb being queried, it has been verified

    Buffer - Supplies a pointer to the buffer where the information is to
        be returned

    Length - Supplies the length of the buffer in bytes, and receives the
        remaining bytes free in the buffer upon return.

Return Value:

    None

--*/

{
    PAGED_CODE();

    //
    //  We support all times on Udfs.
    //

    Buffer->CreationTime = Fcb->Timestamps.CreationTime;
    Buffer->LastWriteTime =
    Buffer->ChangeTime =  Fcb->Timestamps.ModificationTime;
    Buffer->LastAccessTime = Fcb->Timestamps.AccessTime;

    Buffer->FileAttributes = Fcb->FileAttributes | UdfGetExtraFileAttributes( Ccb );

    //
    //  We get the sizes from the header.  Return a size of zero
    //  for all directories.
    //

    if (FlagOn( Fcb->FileAttributes, FILE_ATTRIBUTE_DIRECTORY )) {

        Buffer->AllocationSize.QuadPart =
        Buffer->EndOfFile.QuadPart = 0;

    } else {

        Buffer->AllocationSize.QuadPart = Fcb->AllocationSize.QuadPart;
        Buffer->EndOfFile.QuadPart = Fcb->FileSize.QuadPart;
    }

    //
    //  Update the length and status output variables
    //

    *Length -= sizeof( FILE_NETWORK_OPEN_INFORMATION );

    return;
}