IRP_MJ_READ
时间: 2024-03-10 20:42:05 浏览: 22
IRP_MJ_READ是Windows内核中的一个I/O请求主要函数码,用于处理读取操作。当应用程序或驱动程序需要从设备或文件中读取数据时,它会发送一个IRP_MJ_READ请求给操作系统内核,以便内核执行相应的读取操作。
IRP_MJ_READ的处理过程通常包括以下几个步骤:
1. 应用程序或驱动程序发送IRP_MJ_READ请求给内核。
2. 内核接收到IRP_MJ_READ请求后,会根据请求中的参数确定读取的目标设备或文件。
3. 内核根据目标设备或文件的特性,选择适当的读取方式和策略。
4. 内核执行读取操作,将数据从设备或文件中读取到内存缓冲区中。
5. 内核将读取到的数据返回给应用程序或驱动程序,并完成IRP_MJ_READ请求。
相关问题
KMDF驱动如何获取底层硬盘驱动对象,并向其发送IRP_MJ_READ请求?请给出示例
要获取底层硬盘驱动对象并向其发送IRP_MJ_READ请求,可以使用下面的示例代码:
```
#include <ntddk.h>
NTSTATUS ReadSector(IN PDEVICE_OBJECT DeviceObject, IN PIRP Irp, IN PVOID Context)
{
// 获取IRP的输入输出缓冲区
PIO_STACK_LOCATION irpStack = IoGetCurrentIrpStackLocation(Irp);
PVOID inputBuffer = Irp->AssociatedIrp.SystemBuffer;
PVOID outputBuffer = Irp->UserBuffer;
// 分配一个MDL描述符并锁定输入缓冲区
PMDL mdl = IoAllocateMdl(inputBuffer, irpStack->Parameters.Read.Length, FALSE, FALSE, NULL);
MmBuildMdlForNonPagedPool(mdl);
MmProbeAndLockPages(mdl, KernelMode, IoReadAccess);
// 构造IRP并发送给底层驱动
PIRP readIrp = IoBuildSynchronousFsdRequest(IRP_MJ_READ, DeviceObject, outputBuffer, irpStack->Parameters.Read.Length, &irpStack->Parameters.Read.StartingOffset, NULL, NULL);
NTSTATUS status = IoCallDriver(DeviceObject, readIrp);
// 解锁并释放MDL
MmUnlockPages(mdl);
IoFreeMdl(mdl);
return status;
}
NTSTATUS DispatchReadWrite(IN PDEVICE_OBJECT DeviceObject, IN PIRP Irp)
{
// 获取IRP的输入输出缓冲区
PIO_STACK_LOCATION irpStack = IoGetCurrentIrpStackLocation(Irp);
PVOID inputBuffer = Irp->AssociatedIrp.SystemBuffer;
PVOID outputBuffer = Irp->UserBuffer;
// 如果是读请求,则调用ReadSector函数发送IRP_MJ_READ请求
if (irpStack->MajorFunction == IRP_MJ_READ)
{
return ReadSector(DeviceObject, Irp, NULL);
}
// 如果是写请求,则直接返回成功
if (irpStack->MajorFunction == IRP_MJ_WRITE)
{
Irp->IoStatus.Status = STATUS_SUCCESS;
Irp->IoStatus.Information = irpStack->Parameters.Write.Length;
IoCompleteRequest(Irp, IO_NO_INCREMENT);
return STATUS_SUCCESS;
}
// 其他请求则返回未实现
Irp->IoStatus.Status = STATUS_NOT_IMPLEMENTED;
Irp->IoStatus.Information = 0;
IoCompleteRequest(Irp, IO_NO_INCREMENT);
return STATUS_NOT_IMPLEMENTED;
}
NTSTATUS DriverEntry(IN PDRIVER_OBJECT DriverObject, IN PUNICODE_STRING RegistryPath)
{
// 创建设备对象
PDEVICE_OBJECT deviceObject;
UNICODE_STRING deviceName = RTL_CONSTANT_STRING(L"\\Device\\MyDisk");
UNICODE_STRING symbolicLinkName = RTL_CONSTANT_STRING(L"\\DosDevices\\MyDisk");
NTSTATUS status = IoCreateDevice(DriverObject, 0, &deviceName, FILE_DEVICE_DISK, 0, FALSE, &deviceObject);
if (!NT_SUCCESS(status))
{
return status;
}
// 创建符号链接
status = IoCreateSymbolicLink(&symbolicLinkName, &deviceName);
if (!NT_SUCCESS(status))
{
IoDeleteDevice(deviceObject);
return status;
}
// 设置IRP处理函数
for (ULONG i = 0; i <= IRP_MJ_MAXIMUM_FUNCTION; i++)
{
DriverObject->MajorFunction[i] = DispatchReadWrite;
}
// 获取底层硬盘驱动对象
WCHAR diskName[] = L"\\Device\\Harddisk0\\Partition1";
UNICODE_STRING diskNameUnicode = RTL_CONSTANT_STRING(diskName);
PDEVICE_OBJECT diskObject = IoGetDeviceObjectByDeviceName(&diskNameUnicode);
// 发送IRP_MJ_READ请求
PVOID buffer = ExAllocatePoolWithTag(NonPagedPool, 512, 'MyD');
if (buffer != NULL)
{
LARGE_INTEGER offset = { 0 };
PIRP readIrp = IoBuildSynchronousFsdRequest(IRP_MJ_READ, diskObject, buffer, 512, &offset, NULL, NULL);
if (readIrp != NULL)
{
status = IoCallDriver(diskObject, readIrp);
if (NT_SUCCESS(status))
{
DbgPrint("Read sector successfully!\n");
}
else
{
DbgPrint("Read sector failed with status 0x%X\n", status);
}
}
else
{
DbgPrint("Failed to build IRP\n");
}
ExFreePoolWithTag(buffer, 'MyD');
}
else
{
DbgPrint("Failed to allocate buffer\n");
}
return STATUS_SUCCESS;
}
```
在这个示例中,我们首先创建了一个设备对象并设置了IRP处理函数为DispatchReadWrite。这个函数会根据IRP的MajorFunction字段来判断是否是读请求或写请求,如果是读请求则调用ReadSector函数发送IRP_MJ_READ请求,如果是写请求则直接返回成功。如果是其他请求则返回未实现。
在DriverEntry函数中,我们获取了底层硬盘驱动对象,并发送了一个IRP_MJ_READ请求来读取磁盘扇区。注意,这里的硬盘驱动对象是通过设备名获取的,因此需要知道硬盘的设备名才能获取到正确的对象。
WDF驱动如何向底层磁盘驱动发送IRP_MJ_READ请求读取原始数据?请给出示例
WDF驱动向底层磁盘驱动发送IRP_MJ_READ请求读取原始数据的示例代码如下:
```cpp
NTSTATUS ReadFromDisk(WDFDEVICE Device, PVOID Buffer, ULONG Length)
{
NTSTATUS status = STATUS_SUCCESS;
WDFREQUEST request = NULL;
PIRP irp = NULL;
KEVENT event;
IO_STATUS_BLOCK ioStatusBlock;
// 初始化事件
KeInitializeEvent(&event, NotificationEvent, FALSE);
// 创建请求对象
status = WdfRequestCreate(WDF_NO_OBJECT_ATTRIBUTES, WdfDeviceGetIoTarget(Device), &request);
if (!NT_SUCCESS(status)) {
return status;
}
// 获取IRP对象
irp = WdfRequestWdmGetIrp(request);
// 设置IRP参数
IoSetCompletionRoutine(irp, ReadCompletionRoutine, &event, TRUE, TRUE, TRUE);
irp->Flags |= IRP_BUFFERED_IO | IRP_DEALLOCATE_BUFFER;
irp->AssociatedIrp.SystemBuffer = Buffer;
irp->MdlAddress = NULL;
irp->IoStatus.Status = STATUS_NOT_SUPPORTED;
irp->IoStatus.Information = 0;
irp->Tail.Overlay.Thread = PsGetCurrentThread();
irp->Tail.Overlay.OriginalFileObject = NULL;
irp->Tail.Overlay.AuxiliaryBuffer = NULL;
irp->Flags &= ~(IRP_PAGING_IO | IRP_NOCACHE | IRP_SYNCHRONOUS_API);
// 设置IO栈位置
PIO_STACK_LOCATION irpStack = IoGetNextIrpStackLocation(irp);
irpStack->MajorFunction = IRP_MJ_READ;
irpStack->Parameters.Read.Length = Length;
irpStack->Parameters.Read.ByteOffset.QuadPart = 0;
// 发送IRP请求
status = WdfRequestSend(request, WdfDeviceGetIoTarget(Device), WDF_NO_SEND_OPTIONS);
if (!NT_SUCCESS(status)) {
WdfRequestComplete(request, status);
return status;
}
// 等待请求完成
KeWaitForSingleObject(&event, Executive, KernelMode, FALSE, NULL);
// 获取IO状态
status = irp->IoStatus.Status;
// 完成请求
WdfRequestComplete(request, status);
return status;
}
```
在以上代码中,我们创建了一个WDF请求对象,并获取了其对应的IRP对象,然后设置了IRP的各项参数,最终发送请求并等待请求完成。一旦请求完成,我们就可以通过IRP的IoStatus成员获取IO操作的状态,然后使用WdfRequestComplete函数完成请求。