// Control.cpp -- IOCTL handlers for ioctl driver
// Copyright (C) 1999 by Walter Oney
// All rights reserved
#include "stddcls.h"
#include "driver.h"
#include "ioctls.h"
///////////////////////////////////////////////////////////////////////////////
#pragma PAGEDCODE
NTSTATUS DispatchControl(PDEVICE_OBJECT fdo, PIRP Irp)
{ // DispatchControl
PAGED_CODE();
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_GET_VERSION_BUFFERED: // code == 0x800
{ // IOCTL_GET_VERSION_BUFFERED
if (cbout < sizeof(ULONG))
{ // not enough output data
status = STATUS_INVALID_BUFFER_SIZE;
break;
} // not enough output data
PULONG pversion = (PULONG) Irp->AssociatedIrp.SystemBuffer;
info = sizeof(ULONG);
*pversion = 0x04000A;
break;
} // IOCTL_GET_VERSION_BUFFERED
case IOCTL_GET_VERSION_DIRECT: // code == 0x801
{ // IOCTL_GET_VERSION_DIRECT
if (cbout < sizeof(ULONG))
{ // not enough output data
status = STATUS_INVALID_BUFFER_SIZE;
break;
} // not enough output data
PMDL pmdl = Irp->MdlAddress;
// If the system is low on memory, MmGetSystemAddressForMdl will
// bug-check unless the MDL_MAPPING_CAN_FAIL flag is set in MdlFlags.
// Win2K has a new function named MmGetSystemAddressForMdlSafe that
// returns NULL instead, but Win98 doesn't export it. But, since the
// MDL is supposed to be a completely opaque structure, we should
// not set the flag ourselves.
PULONG pversion = (PULONG) MmGetSystemAddressForMdl(pmdl);
info = sizeof(ULONG);
*pversion = 0x0004000B;
break;
} // IOCTL_GET_VERSION_DIRECT
case IOCTL_GET_VERSION_NEITHER: // code == 0x802
{ // IOCTL_GET_VERSION_NEITHER
if (cbout < sizeof(ULONG))
{ // not enough output data
status = STATUS_INVALID_BUFFER_SIZE;
break;
} // not enough output data
PULONG pversion = (PULONG) Irp->UserBuffer;
if (Irp->RequestorMode != KernelMode)
{ // untrusted caller
__try
{
ProbeForWrite(pversion, sizeof(ULONG), 1);
*pversion = 0x0004000C;
}
__except(EXCEPTION_EXECUTE_HANDLER)
{
status = GetExceptionCode();
break;
}
} // untrusted caller
else
*pversion = 0x0004000C; // trusted caller
info = sizeof(ULONG);
break;
} // IOCTL_GET_VERSION_NEITHER
default:
status = STATUS_INVALID_DEVICE_REQUEST;
break;
} // process request
IoReleaseRemoveLock(&pdx->RemoveLock, Irp);
return CompleteRequest(Irp, status, info);
} // DispatchControl
