windows-nt/Source/XPSP1/NT/base/ntos/wmi/sample/wmifilt/pnp.c
2020-09-26 16:20:57 +08:00

299 lines
8.4 KiB
C

/*++
Copyright (c) 1996 Microsoft Corporation
Module Name:
pnp.c
Abstract: NULL filter driver -- boilerplate code
Author:
ervinp
Environment:
Kernel mode
Revision History:
--*/
#include <WDM.H>
#include "filter.h"
#ifdef ALLOC_PRAGMA
#pragma alloc_text(PAGE, VA_PnP)
#pragma alloc_text(PAGE, GetDeviceCapabilities)
#endif
NTSTATUS VA_PnP(struct DEVICE_EXTENSION *devExt, PIRP irp)
/*++
Routine Description:
Dispatch routine for PnP IRPs (MajorFunction == IRP_MJ_PNP)
Arguments:
devExt - device extension for the targetted device object
irp - IO Request Packet
Return Value:
NT status code
--*/
{
PIO_STACK_LOCATION irpSp;
NTSTATUS status = STATUS_SUCCESS;
BOOLEAN completeIrpHere = FALSE;
BOOLEAN justReturnStatus = FALSE;
PAGED_CODE();
irpSp = IoGetCurrentIrpStackLocation(irp);
DBGOUT(("VA_PnP, minorFunc = %d ", (ULONG)irpSp->MinorFunction));
switch (irpSp->MinorFunction){
case IRP_MN_START_DEVICE:
DBGOUT(("START_DEVICE"));
devExt->state = STATE_STARTING;
/*
* First, send the START_DEVICE irp down the stack
* synchronously to start the lower stack.
* We cannot do anything with our device object
* before propagating the START_DEVICE this way.
*/
IoCopyCurrentIrpStackLocationToNext(irp);
status = CallNextDriverSync(devExt, irp);
if (NT_SUCCESS(status)){
/*
* Now that the lower stack is started,
* do any initialization required by this device object.
*/
status = GetDeviceCapabilities(devExt);
if (NT_SUCCESS(status)){
devExt->state = STATE_STARTED;
/*
* Now that device is started, register with WMI
*/
IoWMIRegistrationControl(devExt->filterDevObj,
WMIREG_ACTION_REGISTER);
}
else {
devExt->state = STATE_START_FAILED;
}
}
else {
devExt->state = STATE_START_FAILED;
}
completeIrpHere = TRUE;
break;
case IRP_MN_QUERY_STOP_DEVICE:
break;
case IRP_MN_STOP_DEVICE:
if (devExt->state == STATE_SUSPENDED){
status = STATUS_DEVICE_POWER_FAILURE;
completeIrpHere = TRUE;
}
else {
/*
* Only set state to STOPPED if the device was
* previously started successfully.
*/
if (devExt->state == STATE_STARTED){
devExt->state = STATE_STOPPED;
}
}
break;
case IRP_MN_QUERY_REMOVE_DEVICE:
/*
* We will pass this IRP down the driver stack.
* However, we need to change the default status
* from STATUS_NOT_SUPPORTED to STATUS_SUCCESS.
*/
irp->IoStatus.Status = STATUS_SUCCESS;
break;
case IRP_MN_SURPRISE_REMOVAL:
DBGOUT(("SURPRISE_REMOVAL"));
/*
* We will pass this IRP down the driver stack.
* However, we need to change the default status
* from STATUS_NOT_SUPPORTED to STATUS_SUCCESS.
*/
irp->IoStatus.Status = STATUS_SUCCESS;
/*
* For now just set the STATE_REMOVING state so that
* we don't do any more IO. We are guaranteed to get
* IRP_MN_REMOVE_DEVICE soon; we'll do the rest of
* the remove processing there.
*/
devExt->state = STATE_REMOVING;
break;
case IRP_MN_REMOVE_DEVICE:
/*
* Check the current state to guard against multiple
* REMOVE_DEVICE IRPs.
*/
DBGOUT(("REMOVE_DEVICE"));
if (devExt->state != STATE_REMOVED){
devExt->state = STATE_REMOVED;
/*
* Send the REMOVE IRP down the stack asynchronously.
* Do not synchronize sending down the REMOVE_DEVICE
* IRP, because the REMOVE_DEVICE IRP must be sent
* down and completed all the way back up to the sender
* before we continue.
*/
IoCopyCurrentIrpStackLocationToNext(irp);
status = IoCallDriver(devExt->physicalDevObj, irp);
justReturnStatus = TRUE;
DBGOUT(("REMOVE_DEVICE - waiting for %d irps to complete...",
devExt->pendingActionCount));
/*
* We must for all outstanding IO to complete before
* completing the REMOVE_DEVICE IRP.
*
* First do an extra decrement on the pendingActionCount.
* This will cause pendingActionCount to eventually
* go to -1 once all asynchronous actions on this
* device object are complete.
* Then wait on the event that gets set when the
* pendingActionCount actually reaches -1.
*/
DecrementPendingActionCount(devExt);
KeWaitForSingleObject( &devExt->removeEvent,
Executive, // wait reason
KernelMode,
FALSE, // not alertable
NULL ); // no timeout
DBGOUT(("REMOVE_DEVICE - ... DONE waiting. "));
/*
* Now that the device is going away unregister with WMI
* Note that we wait until all WMI irps are completed
* before unregistering since unregistering will block
* until all WMI irps are completed.
*/
FilterWmiCleanup(devExt);
IoWMIRegistrationControl(devExt->filterDevObj,
WMIREG_ACTION_DEREGISTER);
/*
* Detach our device object from the lower
* device object stack.
*/
IoDetachDevice(devExt->topDevObj);
/*
* Delete our device object.
* This will also delete the associated device extension.
*/
IoDeleteDevice(devExt->filterDevObj);
}
break;
case IRP_MN_QUERY_DEVICE_RELATIONS:
case IRP_MN_QUERY_PNP_DEVICE_STATE:
default:
break;
}
if (justReturnStatus){
/*
* We've already sent this IRP down the stack asynchronously.
*/
}
else if (completeIrpHere){
irp->IoStatus.Status = status;
IoCompleteRequest(irp, IO_NO_INCREMENT);
}
else {
IoCopyCurrentIrpStackLocationToNext(irp);
status = IoCallDriver(devExt->physicalDevObj, irp);
}
return status;
}
NTSTATUS GetDeviceCapabilities(struct DEVICE_EXTENSION *devExt)
/*++
Routine Description:
Function retrieves the DEVICE_CAPABILITIES descriptor from the device
Arguments:
devExt - device extension for targetted device object
Return Value:
NT status code
--*/
{
NTSTATUS status;
PIRP irp;
PAGED_CODE();
irp = IoAllocateIrp(devExt->physicalDevObj->StackSize, FALSE);
if (irp){
PIO_STACK_LOCATION nextSp = IoGetNextIrpStackLocation(irp);
nextSp->MajorFunction = IRP_MJ_PNP;
nextSp->MinorFunction = IRP_MN_QUERY_CAPABILITIES;
RtlZeroMemory( &devExt->deviceCapabilities,
sizeof(DEVICE_CAPABILITIES));
nextSp->Parameters.DeviceCapabilities.Capabilities =
&devExt->deviceCapabilities;
/*
* For any IRP you create, you must set the default status
* to STATUS_NOT_SUPPORTED before sending it.
*/
irp->IoStatus.Status = STATUS_NOT_SUPPORTED;
status = CallNextDriverSync(devExt, irp);
IoFreeIrp(irp);
}
else {
status = STATUS_INSUFFICIENT_RESOURCES;
}
ASSERT(NT_SUCCESS(status));
return status;
}