// 写操作
VOID RamDiskEvtIoWrite(IN WDFQUEUE Queue,IN WDFREQUEST Request,IN size_t Length)
{
PDEVICE_EXTENSION devExt = QueueGetExtension(Queue)->DeviceExtension;
//从队列对象获得设备扩展
NTSTATUS Status = STATUS_INVALID_PARAMETER;
WDF_REQUEST_PARAMETERS Parameters;
LARGE_INTEGER ByteOffset;
WDFMEMORY hMemory;
//__analysis_assume(Length > 0);
//参数清0
WDF_REQUEST_PARAMETERS_INIT(&Parameters);
//从请求中获取信息
WdfRequestGetParameters(Request, &Parameters);
//写入偏移
ByteOffset.QuadPart = Parameters.Parameters.Write.DeviceOffset;
//检测写入是否合法
if (RamDiskCheckParameters(devExt, ByteOffset, Length))
{
// from output to input
Status = WdfRequestRetrieveInputMemory(Request, &hMemory);
//获得内存状态
if(NT_SUCCESS(Status))
{
// Source # offset in Source memory where the copy has to start # destination
Status = WdfMemoryCopyToBuffer(hMemory, 0,devExt->DiskImage + ByteOffset.LowPart, Length);
// from "from" to "to"
}
}
WdfRequestCompleteWithInformation(Request, Status, (ULONG_PTR)Length);
}
VOID
RamDiskEvtIoWrite(
IN WDFQUEUE Queue,
IN WDFREQUEST Request,
IN size_t Length
)
/*++
Routine Description:
This event is invoked when the framework receives IRP_MJ_WRITE request.
Arguments:
Queue - Handle to the framework queue object that is associated with the
I/O request.
Request - Handle to a framework request object.
Length - Length of the data buffer associated with the request.
The default property of the queue is to not dispatch
zero length read & write requests to the driver and
complete is with status success. So we will never get
a zero length request.
Return Value:
VOID
--*/
{
PDEVICE_EXTENSION devExt = QueueGetExtension(Queue)->DeviceExtension;
NTSTATUS Status = STATUS_INVALID_PARAMETER;
WDF_REQUEST_PARAMETERS Parameters;
LARGE_INTEGER ByteOffset;
WDFMEMORY hMemory;
_Analysis_assume_(Length > 0);
WDF_REQUEST_PARAMETERS_INIT(&Parameters);
WdfRequestGetParameters(Request, &Parameters);
ByteOffset.QuadPart = Parameters.Parameters.Write.DeviceOffset;
if (RamDiskCheckParameters(devExt, ByteOffset, Length)) {
Status = WdfRequestRetrieveInputMemory(Request, &hMemory);
if(NT_SUCCESS(Status)){
Status = WdfMemoryCopyToBuffer(hMemory, // Source
0, // offset in Source memory where the copy has to start
devExt->DiskImage + ByteOffset.LowPart, // destination
Length);
}
}
WdfRequestCompleteWithInformation(Request, Status, (ULONG_PTR)Length);
}
//读操作
VOID RamDiskEvtIoRead(IN WDFQUEUE Queue,IN WDFREQUEST Request,IN size_t Length)
{
PDEVICE_EXTENSION devExt = QueueGetExtension(Queue)->DeviceExtension;
//从队列对象获得设备扩展
NTSTATUS Status = STATUS_INVALID_PARAMETER;
WDF_REQUEST_PARAMETERS Parameters;
LARGE_INTEGER ByteOffset;
WDFMEMORY hMemory;
//__analysis_assume(Length > 0);
//参数清0
WDF_REQUEST_PARAMETERS_INIT(&Parameters);
//从请求中获取信息
WdfRequestGetParameters(Request, &Parameters);
//读取偏移
ByteOffset.QuadPart = Parameters.Parameters.Read.DeviceOffset;
//检测读取是否合法
if (RamDiskCheckParameters(devExt, ByteOffset, Length))
{
//获得内存状态
Status = WdfRequestRetrieveOutputMemory(Request, &hMemory);
if(NT_SUCCESS(Status))
{
// Destination # Offset into the destination ＃ source
Status = WdfMemoryCopyFromBuffer(hMemory,0, devExt->DiskImage + ByteOffset.LowPart, Length);
}
}
WdfRequestCompleteWithInformation(Request, Status, (ULONG_PTR)Length);
}
