filediskthread.c

介绍了NDIS驱动

#include <ntddk.h>
#include "ntifs.h"

VOID
FileDiskThread (
    IN PVOID Context
    )
{
    PDEVICE_OBJECT      device_object;
    PDEVICE_EXTENSION   device_extension;
    PLIST_ENTRY         request;
    PIRP                irp;
    PIO_STACK_LOCATION  io_stack;

    ASSERT(Context != NULL);

    device_object = (PDEVICE_OBJECT) Context;

    device_extension = (PDEVICE_EXTENSION) device_object->DeviceExtension;

    KeSetPriorityThread(KeGetCurrentThread(), LOW_REALTIME_PRIORITY);
	//LOW_REALTIME_PRIORITY在ntddk.h定义为16

    for (;;)//产生死循环，用PsTerminateSystemThread来中止线程
    {
        KeWaitForSingleObject(
            &device_extension->request_event,
            Executive,
            KernelMode,
            FALSE,
            NULL
            );

        if (device_extension->terminate_thread)
        {
            PsTerminateSystemThread(STATUS_SUCCESS);
        }

        while (request = ExInterlockedRemoveHeadList(
            &device_extension->list_head,
            &device_extension->list_lock
            ))
        {
            irp = CONTAINING_RECORD(request, IRP, Tail.Overlay.ListEntry);

            io_stack = IoGetCurrentIrpStackLocation(irp);

            switch (io_stack->MajorFunction)
            {
            case IRP_MJ_READ:
                ZwReadFile(
                    device_extension->file_handle,
                    NULL,
                    NULL,
                    NULL,
                    &irp->IoStatus,
                    MmGetSystemAddressForMdlSafe(irp->MdlAddress, NormalPagePriority),
                    io_stack->Parameters.Read.Length,
                    &io_stack->Parameters.Read.ByteOffset,
                    NULL
                    );
				//NormalPagePriority在ntddk.h中定义为16
                break;

            case IRP_MJ_WRITE:
                if ((io_stack->Parameters.Write.ByteOffset.QuadPart +
                     io_stack->Parameters.Write.Length) >
                     device_extension->file_size.QuadPart)
                {
                    irp->IoStatus.Status = STATUS_INVALID_PARAMETER;
                    irp->IoStatus.Information = 0;
                }
                ZwWriteFile(
                    device_extension->file_handle,
                    NULL,
                    NULL,
                    NULL,
                    &irp->IoStatus,
                    MmGetSystemAddressForMdlSafe(irp->MdlAddress, NormalPagePriority),
                    io_stack->Parameters.Write.Length,
                    &io_stack->Parameters.Write.ByteOffset,
                    NULL
                    );
                break;

            case IRP_MJ_DEVICE_CONTROL:
                switch (io_stack->Parameters.DeviceIoControl.IoControlCode)
                {
                case IOCTL_FILE_DISK_OPEN_FILE:

                    SeImpersonateClient(device_extension->security_client_context, NULL);

                    irp->IoStatus.Status = FileDiskOpenFile(device_object, irp);

                    PsRevertToSelf();

                    break;

                case IOCTL_FILE_DISK_CLOSE_FILE:
                    irp->IoStatus.Status = FileDiskCloseFile(device_object, irp);
                    break;

                default:
                    irp->IoStatus.Status = STATUS_DRIVER_INTERNAL_ERROR;
					//STATUS_DRIVER_INTERNAL_ERROR在ntstatus.h中定义为((NTSTATUS)0xC0000183L)
                }
                break;

            default:
                irp->IoStatus.Status = STATUS_DRIVER_INTERNAL_ERROR;
            }

            IoCompleteRequest(
                irp,
                (CCHAR) (NT_SUCCESS(irp->IoStatus.Status) ?
                IO_DISK_INCREMENT : IO_NO_INCREMENT)
                );
			//IO_DISK_INCREMENT在ntddk.h中定义为1
        }
    }
}