filter.c

键盘睡眠键过滤驱动程序

/*++

Routine Description:

    The plug and play dispatch routines.

    Most of these the driver will completely ignore.
    In all cases it must pass on the IRP to the lower driver.

Arguments:

   DeviceObject - pointer to a device object.

   Irp - pointer to an I/O Request Packet.

Return Value:

      NT status code

--*/
{
    PDEVICE_EXTENSION           deviceExtension; 
    PIO_STACK_LOCATION          irpStack;
    NTSTATUS                    status;
    KEVENT                      event;        

    PAGED_CODE();

    deviceExtension = (PDEVICE_EXTENSION) DeviceObject->DeviceExtension;
    irpStack = IoGetCurrentIrpStackLocation(Irp);

    DebugPrint(("FilterDO %s IRP:0x%x \n", 
                PnPMinorFunctionString(irpStack->MinorFunction), Irp));

    status = STATUS_SUCCESS;
    
    switch (irpStack->MinorFunction) {
    case IRP_MN_START_DEVICE:

        //
        // The device is starting.
        //
        // We cannot touch the device (send it any non pnp irps) until a
        // start device has been passed down to the lower drivers.
        //
        IoCopyCurrentIrpStackLocationToNext(Irp);
        KeInitializeEvent(&event,
                          NotificationEvent,
                          FALSE
                          );

        IoSetCompletionRoutine(Irp,
                               (PIO_COMPLETION_ROUTINE) FilterCompletionRoutine, 
                               &event,
                               TRUE,
                               TRUE,
                               TRUE); // No need for Cancel

        status = IoCallDriver(deviceExtension->NextLowerDriver, Irp);

        if (STATUS_PENDING == status) {
            KeWaitForSingleObject(
               &event,
               Executive, // Waiting for reason of a driver
               KernelMode, // Waiting in kernel mode
               FALSE, // No alert
               NULL); // No timeout
        }

        if (NT_SUCCESS(status) && NT_SUCCESS(Irp->IoStatus.Status)) {
            //
            // As we are successfully now back from our start device
            // we can do work.
            //
            SET_NEW_PNP_STATE(deviceExtension, Started);
        }

        //
        // We must now complete the IRP, since we stopped it in the
        // completion routine with STATUS_MORE_PROCESSING_REQUIRED.
        //
        Irp->IoStatus.Status = status;
        IoCompleteRequest(Irp, IO_NO_INCREMENT);
        return status;
        
    case IRP_MN_REMOVE_DEVICE:
        
        IoSkipCurrentIrpStackLocation(Irp);

        status = IoCallDriver(deviceExtension->NextLowerDriver, Irp);

        SET_NEW_PNP_STATE(deviceExtension, Deleted);

        IoDetachDevice(deviceExtension->NextLowerDriver); 
        IoDeleteDevice(DeviceObject);
        return status;
        
        
    case IRP_MN_QUERY_STOP_DEVICE:
        SET_NEW_PNP_STATE(deviceExtension, StopPending);
        status = STATUS_SUCCESS;
        break;
        
    case IRP_MN_CANCEL_STOP_DEVICE:

        //
        // Check to see whether you have received cancel-stop
        // without first receiving a query-stop. This could happen if someone
        // above us fails a query-stop and passes down the subsequent
        // cancel-stop.
        //
        
        if(StopPending == deviceExtension->DevicePnPState)
        {
            //
            // We did receive a query-stop, so restore.
            //             
            RESTORE_PREVIOUS_PNP_STATE(deviceExtension);
        }
        status = STATUS_SUCCESS; // We must not fail this IRP.
        break;
        
    case IRP_MN_STOP_DEVICE:
        SET_NEW_PNP_STATE(deviceExtension, StopPending);
        status = STATUS_SUCCESS;
        break;

    case IRP_MN_QUERY_REMOVE_DEVICE:

        SET_NEW_PNP_STATE(deviceExtension, RemovePending);
        status = STATUS_SUCCESS;
        break;
       
    case IRP_MN_SURPRISE_REMOVAL:

        SET_NEW_PNP_STATE(deviceExtension, SurpriseRemovePending);
        status = STATUS_SUCCESS;
        break;

    case IRP_MN_CANCEL_REMOVE_DEVICE:

        //
        // Check to see whether you have received cancel-remove
        // without first receiving a query-remove. This could happen if 
        // someone above us fails a query-remove and passes down the 
        // subsequent cancel-remove.
        //
        
        if(RemovePending == deviceExtension->DevicePnPState)
        {
            //
            // We did receive a query-remove, so restore.
            //             
            RESTORE_PREVIOUS_PNP_STATE(deviceExtension);
        }
        status = STATUS_SUCCESS; // We must not fail this IRP.
        break;
         
        
    default:
        //
        // If you don't handle any IRP you must leave the
        // status as is.
        //        
        status = Irp->IoStatus.Status;

        break;
    }

    //
    // Pass the IRP down and forget it.
    //
    Irp->IoStatus.Status = status;
    return FilterPass(DeviceObject, Irp);
}


NTSTATUS
FilterDispatchPower(
    IN PDEVICE_OBJECT    DeviceObject,
    IN PIRP              Irp
    )
/*++

Routine Description:

    This routine is the dispatch routine for power irps.

Arguments:

    DeviceObject - Pointer to the device object.

    Irp - Pointer to the request packet.

Return Value:

    NT Status code
--*/
{
    PDEVICE_EXTENSION   deviceExtension;
    
    PAGED_CODE ();

    deviceExtension = (PDEVICE_EXTENSION) DeviceObject->DeviceExtension;
    PoStartNextPowerIrp(Irp);
    IoSkipCurrentIrpStackLocation(Irp);
    return PoCallDriver(deviceExtension->NextLowerDriver, Irp);
}


    
VOID
FilterUnload(
    IN PDRIVER_OBJECT DriverObject
    )
	
/*++

Routine Description:

    Free all the allocated resources in DriverEntry, etc.

Arguments:

    DriverObject - pointer to a driver object.

Return Value:

    VOID.

--*/
{
    PAGED_CODE ();

    //
    // The device object(s) should be NULL now
    // (since we unload, all the devices objects associated with this
    // driver must be deleted.
    //
    ASSERT(DriverObject->DeviceObject == NULL);
    
    //
    // We should not be unloaded until all the devices we control 
    // have been removed from our queue.  
    //
    DebugPrint (("unload\n"));

    return;
}


#if DBG



PCHAR
PnPMinorFunctionString (
    UCHAR MinorFunction
)
{
    switch (MinorFunction)
    {
        case IRP_MN_START_DEVICE:
            return "IRP_MN_START_DEVICE";
        case IRP_MN_QUERY_REMOVE_DEVICE:
            return "IRP_MN_QUERY_REMOVE_DEVICE";
        case IRP_MN_REMOVE_DEVICE:
            return "IRP_MN_REMOVE_DEVICE";
        case IRP_MN_CANCEL_REMOVE_DEVICE:
            return "IRP_MN_CANCEL_REMOVE_DEVICE";
        case IRP_MN_STOP_DEVICE:
            return "IRP_MN_STOP_DEVICE";
        case IRP_MN_QUERY_STOP_DEVICE:
            return "IRP_MN_QUERY_STOP_DEVICE";
        case IRP_MN_CANCEL_STOP_DEVICE:
            return "IRP_MN_CANCEL_STOP_DEVICE";
        case IRP_MN_QUERY_DEVICE_RELATIONS:
            return "IRP_MN_QUERY_DEVICE_RELATIONS";
        case IRP_MN_QUERY_INTERFACE:
            return "IRP_MN_QUERY_INTERFACE";
        case IRP_MN_QUERY_CAPABILITIES:
            return "IRP_MN_QUERY_CAPABILITIES";
        case IRP_MN_QUERY_RESOURCES:
            return "IRP_MN_QUERY_RESOURCES";
        case IRP_MN_QUERY_RESOURCE_REQUIREMENTS:
            return "IRP_MN_QUERY_RESOURCE_REQUIREMENTS";
        case IRP_MN_QUERY_DEVICE_TEXT:
            return "IRP_MN_QUERY_DEVICE_TEXT";
        case IRP_MN_FILTER_RESOURCE_REQUIREMENTS:
            return "IRP_MN_FILTER_RESOURCE_REQUIREMENTS";
        case IRP_MN_READ_CONFIG:
            return "IRP_MN_READ_CONFIG";
        case IRP_MN_WRITE_CONFIG:
            return "IRP_MN_WRITE_CONFIG";
        case IRP_MN_EJECT:
            return "IRP_MN_EJECT";
        case IRP_MN_SET_LOCK:
            return "IRP_MN_SET_LOCK";
        case IRP_MN_QUERY_ID:
            return "IRP_MN_QUERY_ID";
        case IRP_MN_QUERY_PNP_DEVICE_STATE:
            return "IRP_MN_QUERY_PNP_DEVICE_STATE";
        case IRP_MN_QUERY_BUS_INFORMATION:
            return "IRP_MN_QUERY_BUS_INFORMATION";
        case IRP_MN_DEVICE_USAGE_NOTIFICATION:
            return "IRP_MN_DEVICE_USAGE_NOTIFICATION";
        case IRP_MN_SURPRISE_REMOVAL:
            return "IRP_MN_SURPRISE_REMOVAL";
            
        default:
            return "IRP_MN_?????";
    }
}

#endif