// Control.cpp -- IOCTL handlers for workitem driver
// Copyright (C) 1999 by Walter Oney
// All rights reserved
#include "stddcls.h"
#include "driver.h"
#include "ioctls.h"
struct _RANDOM_JUNK : public _WORK_QUEUE_ITEM
{
PDEVICE_EXTENSION DeviceExtension;
ULONG value;
PIRP nfyirp;
};
typedef _RANDOM_JUNK RANDOM_JUNK, *PRANDOM_JUNK;
VOID WorkItemCallback(PRANDOM_JUNK item);
///////////////////////////////////////////////////////////////////////////////
#pragma PAGEDCODE
NTSTATUS DispatchControl(PDEVICE_OBJECT fdo, PIRP Irp)
{ // DispatchControl
PDEVICE_EXTENSION pdx = (PDEVICE_EXTENSION) fdo->DeviceExtension;
NTSTATUS status = IoAcquireRemoveLock(&pdx->RemoveLock, Irp);
if (!NT_SUCCESS(status))
return CompleteRequest(Irp, status, 0);
ULONG info = 0;
PIO_STACK_LOCATION stack = IoGetCurrentIrpStackLocation(Irp);
ULONG cbin = stack->Parameters.DeviceIoControl.InputBufferLength;
ULONG cbout = stack->Parameters.DeviceIoControl.OutputBufferLength;
ULONG code = stack->Parameters.DeviceIoControl.IoControlCode;
switch (code)
{ // process request
case IOCTL_SUBMIT_ITEM: // code == 0x800
{ // IOCTL_SUBMIT_ITEM
if (cbout < sizeof(ULONG))
status = STATUS_INVALID_PARAMETER;
else
status = GenericCacheControlRequest(pdx->pgx, Irp, &pdx->NotifyIrp);
if (status != STATUS_PENDING)
break; // something wrong, so quit
// Create an executive work item that will complete the notification IRP.
// Since there's no way to cancel a queued work item, leave the remove
// lock claim we already have in place
// Allocate memory for a structure that begins with a work queue item. Use
// the address of this structure as the context argument for the work item
PRANDOM_JUNK item = (PRANDOM_JUNK) ExAllocatePool(PagedPool, sizeof(RANDOM_JUNK));
ExInitializeWorkItem(item, (PWORKER_THREAD_ROUTINE) WorkItemCallback, (PVOID) item);
item->DeviceExtension = pdx;
item->value = *(PULONG) Irp->AssociatedIrp.SystemBuffer;
item->nfyirp = Irp; // only used in call to IoReleaseRemoveLock
// Queue the work item for delayed execution
ExQueueWorkItem(item, DelayedWorkQueue);
KdPrint((DRIVERNAME " - Work item queued\n"));
return STATUS_PENDING;
} // IOCTL_SUBMIT_ITEM
default:
status = STATUS_INVALID_DEVICE_REQUEST;
break;
} // process request
IoReleaseRemoveLock(&pdx->RemoveLock, Irp);
return status == STATUS_PENDING ? status : CompleteRequest(Irp, status, info);
} // DispatchControl
///////////////////////////////////////////////////////////////////////////////
#pragma PAGEDCODE
VOID WorkItemCallback(PRANDOM_JUNK item)
{ // WorkItemCallback
PAGED_CODE();
KdPrint((DRIVERNAME " - Work item callback has occurred\n"));
PDEVICE_EXTENSION pdx = item->DeviceExtension;
ULONG value = item->value;
PIRP nfyirp = GenericUncacheControlRequest(pdx->pgx, &pdx->NotifyIrp);
if (nfyirp)
{ // complete the notification IRP
*(PULONG) nfyirp->AssociatedIrp.SystemBuffer = item->value;
CompleteRequest(nfyirp, STATUS_SUCCESS, sizeof(ULONG));
} // complete the notification IRP
IoReleaseRemoveLock(&pdx->RemoveLock, item->nfyirp);
ExFreePool(item);
} // WorkItemCallback
