return STATUS_SUCCESS;
}


VOID
PtInstanceTeardownStart (
    __in PCFLT_RELATED_OBJECTS FltObjects,
    __in FLT_INSTANCE_TEARDOWN_FLAGS Flags
    )
/*++

Routine Description:

    This routine is called at the start of instance teardown.

Arguments:

    FltObjects - Pointer to the FLT_RELATED_OBJECTS data structure containing
        opaque handles to this filter, instance and its associated volume.

    Flags - Reason why this instance is been deleted.

Return Value:

    None.

--*/
{
    UNREFERENCED_PARAMETER( FltObjects );
    UNREFERENCED_PARAMETER( Flags );

    PAGED_CODE();

    PT_DBG_PRINT( PTDBG_TRACE_ROUTINES,
                  ("PassThrough!PtInstanceTeardownStart: Entered\n") );
}


VOID
PtInstanceTeardownComplete (
    __in PCFLT_RELATED_OBJECTS FltObjects,
    __in FLT_INSTANCE_TEARDOWN_FLAGS Flags
    )
/*++

Routine Description:

    This routine is called at the end of instance teardown.

Arguments:

    FltObjects - Pointer to the FLT_RELATED_OBJECTS data structure containing
        opaque handles to this filter, instance and its associated volume.

    Flags - Reason why this instance is been deleted.

Return Value:

    None.

--*/
{
    UNREFERENCED_PARAMETER( FltObjects );
    UNREFERENCED_PARAMETER( Flags );

    PAGED_CODE();

    PT_DBG_PRINT( PTDBG_TRACE_ROUTINES,
                  ("PassThrough!PtInstanceTeardownComplete: Entered\n") );
}


/*************************************************************************
    MiniFilter initialization and unload routines.
*************************************************************************/

NTSTATUS
DriverEntry (
    __in PDRIVER_OBJECT DriverObject,
    __in PUNICODE_STRING RegistryPath
    )
/*++

Routine Description:

    This is the initialization routine for this miniFilter driver.  This
    registers with FltMgr and initializes all global data structures.

Arguments:

    DriverObject - Pointer to driver object created by the system to
        represent this driver.

    RegistryPath - Unicode string identifying where the parameters for this
        driver are located in the registry.

Return Value:

    Returns STATUS_SUCCESS.

--*/
{
    NTSTATUS status;

    UNREFERENCED_PARAMETER( RegistryPath );

    PT_DBG_PRINT( PTDBG_TRACE_ROUTINES,
                  ("PassThrough!DriverEntry: Entered\n") );

    //
    //  Register with FltMgr to tell it our callback routines
    //

    status = FltRegisterFilter( DriverObject,
                                &FilterRegistration,
                                &gFilterHandle );

    ASSERT( NT_SUCCESS( status ) );

    if (NT_SUCCESS( status )) {

        //
        //  Start filtering i/o
        //

        status = FltStartFiltering( gFilterHandle );

        if (!NT_SUCCESS( status )) {

            FltUnregisterFilter( gFilterHandle );
        }
    }

    return status;
}

NTSTATUS
PtUnload (
    __in FLT_FILTER_UNLOAD_FLAGS Flags
    )
/*++

Routine Description:

    This is the unload routine for this miniFilter driver. This is called
    when the minifilter is about to be unloaded. We can fail this unload
    request if this is not a mandatory unloaded indicated by the Flags
    parameter.

Arguments:

    Flags - Indicating if this is a mandatory unload.

Return Value:

    Returns the final status of this operation.

--*/
{
    UNREFERENCED_PARAMETER( Flags );

    PAGED_CODE();

    PT_DBG_PRINT( PTDBG_TRACE_ROUTINES,
                  ("PassThrough!PtUnload: Entered\n") );

    FltUnregisterFilter( gFilterHandle );

    return STATUS_SUCCESS;
}


/*************************************************************************
    MiniFilter callback routines.
*************************************************************************/
FLT_PREOP_CALLBACK_STATUS
PtPreOperationPassThrough (
    __inout PFLT_CALLBACK_DATA Data,
    __in PCFLT_RELATED_OBJECTS FltObjects,
    __deref_out_opt PVOID *CompletionContext
    )
/*++

Routine Description:

    This routine is the main pre-operation dispatch routine for this
    miniFilter. Since this is just a simple passThrough miniFilter it
    does not do anything with the callbackData but rather return
    FLT_PREOP_SUCCESS_WITH_CALLBACK thereby passing it down to the next
    miniFilter in the chain.

    This is non-pageable because it could be called on the paging path

Arguments:

    Data - Pointer to the filter callbackData that is passed to us.

    FltObjects - Pointer to the FLT_RELATED_OBJECTS data structure containing
        opaque handles to this filter, instance, its associated volume and
        file object.

    CompletionContext - The context for the completion routine for this
        operation.

Return Value:

    The return value is the status of the operation.

--*/
{
    NTSTATUS status;

    UNREFERENCED_PARAMETER( FltObjects );
    UNREFERENCED_PARAMETER( CompletionContext );

    PT_DBG_PRINT( PTDBG_TRACE_ROUTINES,
                  ("PassThrough!PtPreOperationPassThrough: Entered\n") );

    //
    //  See if this is an operation we would like the operation status
    //  for.  If so request it.
    //
    //  NOTE: most filters do NOT need to do this.  You only need to make
    //        this call if, for example, you need to know if the oplock was
    //        actually granted.
    //

    if (PtDoRequestOperationStatus( Data )) {

        status = FltRequestOperationStatusCallback( Data,
                                                    PtOperationStatusCallback,
                                                    (PVOID)(++OperationStatusCtx) );
        if (!NT_SUCCESS(status)) {

            PT_DBG_PRINT( PTDBG_TRACE_OPERATION_STATUS,
                          ("PassThrough!PtPreOperationPassThrough: FltRequestOperationStatusCallback Failed, status=%08x\n",
                           status) );
        }
    }

    return FLT_PREOP_SUCCESS_WITH_CALLBACK;
}



VOID
PtOperationStatusCallback (
    __in PCFLT_RELATED_OBJECTS FltObjects,
    __in PFLT_IO_PARAMETER_BLOCK ParameterSnapshot,
    __in NTSTATUS OperationStatus,
    __in PVOID RequesterContext
    )
/*++

Routine Description:

    This routine is called when the given operation returns from the call
    to IoCallDriver.  This is useful for operations where STATUS_PENDING
    means the operation was successfully queued.  This is useful for OpLocks
    and directory change notification operations.

    This callback is called in the context of the originating thread and will
    never be called at DPC level.  The file object has been correctly
    referenced so that you can access it.  It will be automatically
    dereferenced upon return.

    This is non-pageable because it could be called on the paging path

Arguments:

    FltObjects - Pointer to the FLT_RELATED_OBJECTS data structure containing
        opaque handles to this filter, instance, its associated volume and
        file object.

    RequesterContext - The context for the completion routine for this
        operation.

    OperationStatus -

Return Value:

    The return value is the status of the operation.

--*/
{
    PT_DBG_PRINT( PTDBG_TRACE_ROUTINES,
                  ("PassThrough!PtOperationStatusCallback: Entered\n") );

    PT_DBG_PRINT( PTDBG_TRACE_OPERATION_STATUS,
                  ("PassThrough!PtOperationStatusCallback: Status=%08x ctx=%p IrpMj=%02x.%02x \"%s\"\n",
                   OperationStatus,
                   RequesterContext,
                   ParameterSnapshot->MajorFunction,
                   ParameterSnapshot->MinorFunction,
                   FltGetIrpName(ParameterSnapshot->MajorFunction)) );
}


FLT_POSTOP_CALLBACK_STATUS
PtPostOperationPassThrough (
    __inout PFLT_CALLBACK_DATA Data,
    __in PCFLT_RELATED_OBJECTS FltObjects,
    __in_opt PVOID CompletionContext,
    __in FLT_POST_OPERATION_FLAGS Flags
    )
/*++

Routine Description:

    This routine is the post-operation completion routine for this
    miniFilter.

    This is non-pageable because it may be called at DPC level.

Arguments:

    Data - Pointer to the filter callbackData that is passed to us.

    FltObjects - Pointer to the FLT_RELATED_OBJECTS data structure containing
        opaque handles to this filter, instance, its associated volume and
        file object.

    CompletionContext - The completion context set in the pre-operation routine.

    Flags - Denotes whether the completion is successful or is being drained.

Return Value:

    The return value is the status of the operation.

--*/
{
    UNREFERENCED_PARAMETER( Data );
    UNREFERENCED_PARAMETER( FltObjects );
    UNREFERENCED_PARAMETER( CompletionContext );
    UNREFERENCED_PARAMETER( Flags );

    PT_DBG_PRINT( PTDBG_TRACE_ROUTINES,
                  ("PassThrough!PtPostOperationPassThrough: Entered\n") );

    return FLT_POSTOP_FINISHED_PROCESSING;
}


FLT_PREOP_CALLBACK_STATUS
PtPreOperationNoPostOperationPassThrough (
    __inout PFLT_CALLBACK_DATA Data,
    __in PCFLT_RELATED_OBJECTS FltObjects,
    __deref_out_opt PVOID *CompletionContext
    )
/*++

Routine Description:

    This routine is the main pre-operation dispatch routine for this
    miniFilter. Since this is just a simple passThrough miniFilter it
    does not do anything with the callbackData but rather return
    FLT_PREOP_SUCCESS_WITH_CALLBACK thereby passing it down to the next
    miniFilter in the chain.

    This is non-pageable because it could be called on the paging path

Arguments:

    Data - Pointer to the filter callbackData that is passed to us.

    FltObjects - Pointer to the FLT_RELATED_OBJECTS data structure containing
        opaque handles to this filter, instance, its associated volume and
        file object.

    CompletionContext - The context for the completion routine for this
        operation.

Return Value:

    The return value is the status of the operation.

--*/
{
    UNREFERENCED_PARAMETER( Data );
    UNREFERENCED_PARAMETER( FltObjects );
    UNREFERENCED_PARAMETER( CompletionContext );

    PT_DBG_PRINT( PTDBG_TRACE_ROUTINES,
                  ("PassThrough!PtPreOperationNoPostOperationPassThrough: Entered\n") );

    return FLT_PREOP_SUCCESS_NO_CALLBACK;
}


BOOLEAN
PtDoRequestOperationStatus(
    __in PFLT_CALLBACK_DATA Data
    )
/*++

Routine Description:

    This identifies those operations we want the operation status for.  These
    are typically operations that return STATUS_PENDING as a normal completion
    status.

Arguments:

Return Value:

    TRUE - If we want the operation status
    FALSE - If we don't

--*/
{
    PFLT_IO_PARAMETER_BLOCK iopb = Data->Iopb;

    //
    //  return boolean state based on which operations we are interested in
    //

    return (BOOLEAN)

            //
            //  Check for oplock operations
            //

             (((iopb->MajorFunction == IRP_MJ_FILE_SYSTEM_CONTROL) &&
               ((iopb->Parameters.FileSystemControl.Common.FsControlCode == FSCTL_REQUEST_FILTER_OPLOCK)  ||
                (iopb->Parameters.FileSystemControl.Common.FsControlCode == FSCTL_REQUEST_BATCH_OPLOCK)   ||
                (iopb->Parameters.FileSystemControl.Common.FsControlCode == FSCTL_REQUEST_OPLOCK_LEVEL_1) ||
                (iopb->Parameters.FileSystemControl.Common.FsControlCode == FSCTL_REQUEST_OPLOCK_LEVEL_2)))

              ||

              //
              //    Check for directy change notification
              //

              ((iopb->MajorFunction == IRP_MJ_DIRECTORY_CONTROL) &&
               (iopb->MinorFunction == IRP_MN_NOTIFY_CHANGE_DIRECTORY))
             );
}