IO请求包-IRP

IRP（IO请求包）用于win32和驱动程序通讯，NT内核有一个组件叫做IO管理器。IO管理器负责IRP的分发，驱动程序里创建好设备并且创建好符号链接后，Win32就可以加载驱动了。而要让一个驱动可以处理IRP，必需给驱动添加IRP处理例程。

添加的方法就是再DriverEntry里面对驱动对象DriverObject操作。该参数是一个指针，指向驱动对象，驱动对象内部有一个MajorFunction数组，该数组的类型是
NTSTATUS  (*PDRIVER_DISPATCH) (IN PDEVICE_OBJECT DeviceObject,IN PIRP Irp) 。这是一个函数指针，指向每个IRP对于的处理例程。最后就是为所有需要处理的IRP实现对应的例程。

 

#ifndef _IRP_H_
#define _IRP_H_
/*device type*/
/*0-32767 reserved for M$ */
#define FILE_DEVICE_IRP 0x00008011 
/*IRP*/
/*0-2047 reserved for M$*/
#define IRP_IOCTL_INDEX 0x810 
 

#define IOCTL_IRP_1     CTL_CODE(FILE_DEVICE_IRP,  \
                                     IRP_IOCTL_INDEX, \
                                     METHOD_BUFFERED, \
                                     FILE_ANY_ACCESS)

#define IOCTL_IRP_2     CTL_CODE(FILE_DEVICE_IRP,  \
                                     IRP_IOCTL_INDEX+1,\
                                     METHOD_BUFFERED,   \
                                     FILE_ANY_ACCESS)

#define IOCTL_IRP_3     CTL_CODE(FILE_DEVICE_IRP,  \
                                     IRP_IOCTL_INDEX+2,\
                                     METHOD_BUFFERED,   \
                                     FILE_ANY_ACCESS)            

#endif /*_IRP_H_*/




 

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


/*
function declares
*/
NTSTATUS DispatchCreate(IN PDEVICE_OBJECT DeviceObject,IN PIRP Irp);
NTSTATUS DispatchClose(IN PDEVICE_OBJECT DeviceObject,IN PIRP Irp);
NTSTATUS DispatchDeviceControl(IN PDEVICE_OBJECT DeviceObject,IN PIRP Irp);
VOID     DriverUnload(PDRIVER_OBJECT DriverObject);

/*
DriverEntry
*/
NTSTATUS DriverEntry(IN PDRIVER_OBJECT DriverObject,IN PUNICODE_STRING RegistryPath)
{
    UNICODE_STRING  DeviceNameUnicodeString;
    UNICODE_STRING  DeviceLinkUnicodeString;
    NTSTATUS        ntStatus;
    PDEVICE_OBJECT  DeviceObject = NULL;

    DbgPrint ("Entering DriverEntry");

    RtlInitUnicodeString (&DeviceNameUnicodeString, L"\\Device\\irp");

    // Create an EXCLUSIVE device object (only 1 thread at a time
    // can make requests to this device).

    ntStatus = IoCreateDevice (DriverObject,
                                0,
                                &DeviceNameUnicodeString,
                                FILE_DEVICE_IRP,
                                0,
                                TRUE,
                                &DeviceObject);

    if (NT_SUCCESS(ntStatus))
    {
    // Create dispatch points for device control, create, close.

        DriverObject->MajorFunction[IRP_MJ_CREATE]         = DispatchCreate;
        DriverObject->MajorFunction[IRP_MJ_CLOSE]          = DispatchClose;
        DriverObject->MajorFunction[IRP_MJ_DEVICE_CONTROL] = DispatchDeviceControl;
        DriverObject->DriverUnload                         = DriverUnload;

        // Create a symbolic link, e.g. a name that a Win32 app can specify
        // to open the device.

        RtlInitUnicodeString (&DeviceLinkUnicodeString, L"\\DosDevices\\irp");

        ntStatus = IoCreateSymbolicLink (&DeviceLinkUnicodeString,
        &DeviceNameUnicodeString);

        if (!NT_SUCCESS(ntStatus))
        {
        // Symbolic link creation failed- note this & then delete the
        // device object (it's useless if a Win32 app can't get at it).

            DbgPrint ("ERROR: IoCreateSymbolicLink failed");

            IoDeleteDevice (DeviceObject);
        }

    }
    else
    {
        DbgPrint ("ERROR: IoCreateDevice failed");
    }

    DbgPrint ("Leaving DriverEntry");

    return ntStatus;
}


/*DriverUnload*/
VOID DriverUnload(PDRIVER_OBJECT DriverObject)
{
    UNICODE_STRING DeviceLinkUnicodeString;
    NTSTATUS ntStatus;

    DbgPrint ("Entering DriverUnload");

    RtlInitUnicodeString (&DeviceLinkUnicodeString, L"\\DosDevices\\irp");

    ntStatus = IoDeleteSymbolicLink (&DeviceLinkUnicodeString);

    if (NT_SUCCESS(ntStatus))
    {
        IoDeleteDevice (DriverObject->DeviceObject);
    }
    else
    {
        DbgPrint ("ERROR: IoDeleteSymbolicLink");
    }

    DbgPrint ("Leaving DriverUnload");
}
/*
DispatchCreate
*/
NTSTATUS DispatchCreate(IN PDEVICE_OBJECT DeviceObject,IN PIRP Irp)
{
    DbgPrint("CreateFile called");

    Irp->IoStatus.Status      = STATUS_SUCCESS;
    Irp->IoStatus.Information = 0;
    IoCompleteRequest (Irp, IO_NO_INCREMENT);

    return STATUS_SUCCESS;
}
/*
DispatchClose
*/
NTSTATUS DispatchClose(IN PDEVICE_OBJECT DeviceObject,IN PIRP Irp)
{
    DbgPrint("CloseHandle called");

    Irp->IoStatus.Status      = STATUS_SUCCESS;
    Irp->IoStatus.Information = 0;
    IoCompleteRequest (Irp, IO_NO_INCREMENT);

    return STATUS_SUCCESS;
}

/*DispatchDeviceControl*/

NTSTATUS DispatchDeviceControl(IN PDEVICE_OBJECT DeviceObject,IN PIRP Irp)
{
    PIO_STACK_LOCATION      irpStack;                                
    NTSTATUS                 ntStatus;
    ULONG                     IoControlCodes;
    irpStack=IoGetCurrentIrpStackLocation(Irp);
    
    Irp->IoStatus.Status      = STATUS_SUCCESS;
    Irp->IoStatus.Information = 0;    
    IoControlCodes=irpStack->Parameters.DeviceIoControl.IoControlCode;
    
    switch (IoControlCodes)
    {        
    case IOCTL_IRP_1:
        DbgPrint("irp1\n");
        break;
    case IOCTL_IRP_2:
        DbgPrint("irp2\n");
        break;
    case IOCTL_IRP_3:
        DbgPrint("irp3\n");
        break;
    default:                                            
        ntStatus = STATUS_INVALID_DEVICE_REQUEST;
        break;
    }
    ntStatus=Irp->IoStatus.Status;
    IoCompleteRequest (Irp, IO_NO_INCREMENT);    
    
    return ntStatus;

}





 

/*win32产生IRP*/

HANDLE hDriver= CreateFile("\\\\.\\irp",
                            GENERIC_WRITE | GENERIC_READ, 
                            0, 
                            NULL, 
                            OPEN_EXISTING, 
                            0, 
                            NULL); 

...                            
CloseHandle(hDriver);
...
DeviceIoControl(hDriver,
                IOCTL_IRP_1,
                NULL, 0, // no input buffer
                NULL, 0,     // output buffer
                &junk,                 // # bytes returned
                (LPOVERLAPPED) NULL) ; // synchronous I/O