Create IRP

NTDEV
1

Hello,

I would like to create a IRP from my upper filter driver in order to retrieve the InstanceId from the PDO. 

Is there any example to create this kind of IRP?

I perform these following instructions while I receive IRP_MN_START_DEVICE in the filter driver.

My system crashes when the system loads this driver.

Anybody could help me to fix this small problem…

// START_DEVICE

// Instance Id 

        BufLen = 8 * sizeof(WCHAR); 

  

        Buffer = ExAllocatePool(PagedPool, BufLen);

        if (!Buffer) {

           status = STATUS_INSUFFICIENT_RESOURCES;

           return status;

        }

// create IRP here

        irp = IoBuildAsynchronousFsdRequest(IRP_MJ_PNP,

                                            deviceExtension->NextLowerDriver,

                                            Buffer,

                                            BufLen,

                                            &largeInt,

                                            NULL);

  IoSetCompletionRoutine(irp,

          (PIO_COMPLETION_ROUTINE) FilterQueryInstanceRoutine,

          NULL,

          TRUE,

          TRUE,

          TRUE);

        irpStack_2 = IoGetNextIrpStackLocation(irp);

        irpStack_2->MajorFunction = IRP_MJ_PNP;

  irpStack_2->MinorFunction = IRP_MN_QUERY_ID;

  irpStack_2->Parameters.QueryId.IdType = BusQueryInstanceID;

 

  KeInitializeEvent(&syncEvent, SynchronizationEvent, FALSE);

  status = IoCallDriver(deviceExtension->NextLowerDriver, irp);

        if (status == STATUS_PENDING) {

            KeWaitForSingleObject(&syncEvent, Executive, KernelMode, FALSE, NULL);

            status = irp->IoStatus.Status;

        }

 

2
  1. your code segment is (more than) a bit incomplete so there could be
    numerous bugs not revealed by the sample. In addition you provided no actual
    data from your system crash, like a bug check code and a stack trace. That
    sort of information is really helpful in isolating exactly what this
    specific problem is, especially as my guess is that you are having multiple
    problems, so you could be fixing bugs and still getting crashes.

1.) if you are going to do a ‘send and wait’ you should just use
IoBuildSynchronousFsdRequest.

  1. you should not specify a data buffer for pnp irps. These sort of irps
    have their own peculiar rules for how they send data. Generally data is
    transferred back towards the originator using Irp.IoStatus.Information. In
    your specific case, as is clearly described in the DDK, the instance ID
    string is returned in IRP.IoStatus.Information, and it is your
    responsibility to deallocate this buffer after you are done with it.

  2. you MUST set IRP.IoStatus.Status to STATUS_NOT_SUPPORTED.

  3. You don’t need a StartingOffset parameter, so just set this to NULL.

  4. If you take my advice and use IoBuildSynchronousFsdRequest you don’t need
    a completion handler, and as that is most likely where most of your bugs
    are, this is goodness.

  5. You don’t set the MajorFunction field - it is set by the call to
    IoBuildSynchronousFsdRequest. Just set the MinorFunction field.

  6. you should set IRP.IoStatus.Information to NULL.

  7. FYI: it looks like your call to IoSetCompletionHandler does not pass the
    address of your ‘syncEvent’. How exactly was your completion handler
    supposed to set this event?

=====================
Mark Roddy
Windows .NET/XP/2000 Consulting
Hollis Technology Solutions 603-321-1032
www.hollistech.com

From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of xxxxx@mcdi.com
Sent: Monday, March 22, 2004 3:52 PM
To: Windows System Software Devs Interest List
Subject: [ntdev] Create IRP

Hello,

I would like to create a IRP from my upper filter driver in order to
retrieve the InstanceId from the PDO.

Is there any example to create this kind of IRP?

I perform these following instructions while I receive IRP_MN_START_DEVICE
in the filter driver.

My system crashes when the system loads this driver.

Anybody could help me to fix this small problem…

// START_DEVICE
// Instance Id
BufLen = 8 * sizeof(WCHAR);

Buffer = ExAllocatePool(PagedPool, BufLen);
if (!Buffer) {
status = STATUS_INSUFFICIENT_RESOURCES;
return status;
}

// create IRP here
irp = IoBuildAsynchronousFsdRequest(IRP_MJ_PNP,

deviceExtension->NextLowerDriver,
Buffer,
BufLen,
&largeInt,
NULL);

IoSetCompletionRoutine(irp,
(PIO_COMPLETION_ROUTINE) FilterQueryInstanceRoutine,
NULL,
TRUE,
TRUE,
TRUE);
irpStack_2 = IoGetNextIrpStackLocation(irp);

irpStack_2->MajorFunction = IRP_MJ_PNP;

irpStack_2->MinorFunction = IRP_MN_QUERY_ID;
irpStack_2->Parameters.QueryId.IdType = BusQueryInstanceID;

KeInitializeEvent(&syncEvent, SynchronizationEvent, FALSE);

status = IoCallDriver(deviceExtension->NextLowerDriver, irp);

if (status == STATUS_PENDING) {
KeWaitForSingleObject(&syncEvent, Executive, KernelMode, FALSE,
NULL);
status = irp->IoStatus.Status;
}

— Questions? First check the Kernel Driver FAQ at
http://www.osronline.com/article.cfm?id=256 You are currently subscribed to
ntdev as: xxxxx@hollistech.com To unsubscribe send a blank email to
xxxxx@lists.osr.com