[转&精]IO_STACK_LOCATION与IRP的一点笔记

 1 VOID
 2 IoSetCompletionRoutine(
 3     __in PIRP Irp,
 4     __in_opt PIO_COMPLETION_ROUTINE CompletionRoutine,
 5     __in_opt __drv_aliasesMem PVOID Context,
 6     __in BOOLEAN InvokeOnSuccess,
 7     __in BOOLEAN InvokeOnError,
 8     __in BOOLEAN InvokeOnCancel
 9     )
10 {
11     PIO_STACK_LOCATION irpSp;
12     ASSERT( (InvokeOnSuccess || InvokeOnError || InvokeOnCancel) ? (CompletionRoutine != NULL) : TRUE );
13     irpSp = IoGetNextIrpStackLocation(Irp);
14     irpSp->CompletionRoutine = CompletionRoutine;
15     irpSp->Context = Context;
16     irpSp->Control = 0;
17  
18     if (InvokeOnSuccess) {
19         irpSp->Control = SL_INVOKE_ON_SUCCESS;
20     }
21  
22     if (InvokeOnError) {
23         irpSp->Control |= SL_INVOKE_ON_ERROR;
24     }
25  
26     if (InvokeOnCancel) {
27         irpSp->Control |= SL_INVOKE_ON_CANCEL;
28     }
29 }  

 1 NTSTATUS CompletionRoutine(PDEVICE_OBJECT device, PIRP Irp, PVOID context)
 2 {
 3     if (Irp->PendingReturned)
 4     {
 5         IoMarkIrpPending(Irp);
 6     }
 7     // ...
 8  
 9     return STATUS_SUCCESS /* or some other status code */ ;
10 }  

1 NTSTATUS ForwardAndForget(PDEVICE_OBJECT fdo, PIRP Irp)
2 {
3     PDEVICE_EXTENSION pdx = (PDEVICE_EXTENSION) fdo->DeviceExtension;
4     IoSkipCurrentIrpStackLocation(Irp);
5     return IoCallDriver(pdx->LowerDeviceObject, Irp);
6 }  

 1 VOID
 2 IoCopyCurrentIrpStackLocationToNext(
 3     __inout PIRP Irp
 4 )
 5 {
 6     PIO_STACK_LOCATION irpSp;
 7     PIO_STACK_LOCATION nextIrpSp;
 8     irpSp = IoGetCurrentIrpStackLocation(Irp);
 9     nextIrpSp = IoGetNextIrpStackLocation(Irp);
10     RtlCopyMemory( nextIrpSp, irpSp, FIELD_OFFSET(IO_STACK_LOCATION, CompletionRoutine));
11     nextIrpSp->Control = 0;
12 }  

1 VOID
2 IoSkipCurrentIrpStackLocation (
3     __inout PIRP Irp
4 )
5 {
6     ASSERT(Irp->CurrentLocation <= Irp->StackCount);
7     Irp->CurrentLocation++;
8     Irp->Tail.Overlay.CurrentStackLocation++;
9 }  

 1 NTSTATUS ForwardAndWait(PDEVICE_OBJECT fdo, PIRP Irp)
 2 {
 3     KEVENT event;
 4     KeInitializeEvent(&event, NotificationEvent, FALSE);
 5     IoCopyCurrentIrpStackLocationToNext(Irp);
 6     IoSetCompletionRoutine(Irp,
 7             (PIO_COMPLETION_ROUTINE) OnRequestComplete,
 8             (PVOID) &event,
 9             TRUE,
10             TRUE,
11             TRUE);
12     PDEVICE_EXTENSION pdx = (PDEVICE_EXTENSION) fdo->DeviceExtension;
13     IoCallDriver(pdx->LowerDeviceObject, Irp);
14     KeWaitForSingleObject(&event, Executive, KernelMode, FALSE, NULL);
15     return Irp->IoStatus.Status;
16 }
17  
18 NTSTATUS OnRequestComplete(PDEVICE_OBJECT fdo, PIRP Irp, PKEVENT pev)
19 {
20     KeSetEvent(pev, 0, FALSE);
21     return STATUS_MORE_PROCESSING_REQUIRED;
22 }