SpbRequestCaptureIoOtherTransferList function (spbcx.h)

Artikel
04/01/2021

The SpbRequestCaptureIoOtherTransferList method retrieves the SPB_TRANSFER_LIST structure in the input buffer of the custom IOCTL request.

Syntax

NTSTATUS SpbRequestCaptureIoOtherTransferList(
  SPBREQUEST Request
);

Parameters

Request

An SPBREQUEST handle to the custom IOCTL request. The SPB controller driver previously received this handle through one of its registered event callback functions.

Return value

SpbRequestCaptureIoOtherTransferList returns STATUS_SUCCESS if the call is successful. Possible return values include the following error codes.

Return value	Description
STATUS_INVALID_PARAMETER	The SPBREQUEST parameter is invalid or the SPB_TRANSFER_LIST structure in the request is formatted incorrectly.
STATUS_INSUFFICIENT_RESOURCES	Cannot allocate the system resources that are required for this operation.

Remarks

This method must be called in the context of the process in which the buffer addresses are valid. Typically, the SPB controller driver calls this method from the EvtIoInCallerContext event callback function that the driver supplies as an input parameter to the SpbControllerSetIoOtherCallback method.

The maximum IRQL at which the SPB controller driver can call this method depends on whether the originator of the I/O request is running in user mode or in kernel mode. If the request originated from user mode, the driver must call this method at PASSIVE_LEVEL. If the request originated from kernel mode, the driver must call this method at IRQL <= DISPATCH_LEVEL. The driver can call the WdfRequestGetRequestorMode method to determine the originator's mode. However, this call is typically unnecessary because the driver can rely on the SPB framework extension (SpbCx) to call the driver's EvtIoInCallerContext function at the appropriate IRQL.

Examples

The following code example shows how an SPB controller driver's EvtIoInCallerContext event callback function can use the SpbRequestCaptureIoOtherTransferList method to obtain the I/O buffer or buffers from a custom IOCTL request.

VOID
EvtIoInCallerContext(
    _In_  WDFDEVICE   SpbController,
    _In_  WDFREQUEST  FxRequest
    ) 
{
    NTSTATUS status;

    //
    // NOTE: The driver should check for custom IOCTLs that this
    // driver handles. If an IOCTL is not recognized, mark the
    // request as STATUS_NOT_SUPPORTED, and complete the request.
    //

    status = SpbRequestCaptureIoOtherTransferList((SPBREQUEST)FxRequest);

    //
    // If the preceding call fails, the driver must complete the
    // request instead of queueing the request.
    //

    if (!NT_SUCCESS(status))
    {
        goto exit;
    }

    status = WdfDeviceEnqueueRequest(SpbController, FxRequest);

    if (!NT_SUCCESS(status))
    {
        goto exit;
    }

exit:

    if (!NT_SUCCESS(status))
    {
        WdfRequestComplete(FxRequest, status);
    }
}

Requirements

Requirement	Value
Minimum supported client	Available starting with Windows 8.
Target Platform	Universal
Header	spbcx.h
Library	Spbcxstubs.lib
IRQL	See Remarks.

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