IOCTL_GET_HCD_DRIVERKEY_NAME control code

The IOCTL_GET_HCD_DRIVERKEY_NAME I/O control request retrieves the driver key name in the registry for a USB host controller driver.

IOCTL_GET_HCD_DRIVERKEY_NAME is a user-mode I/O control request. This request targets the USB host controller (GUID_DEVINTERFACE_USB_HOST_CONTROLLER).

Input Buffer

None.

Input Buffer Length

None.

Output Buffer

The AssociatedIrp.SystemBuffer member specifies the address of a caller-allocated buffer that contains a USB_HCD_DRIVERKEY_NAME structure. On output, this structure holds the driver key name. For more information, see Remarks.

Output Buffer Length

The size of this buffer is specified in the Parameters.DeviceIoControl.OutputBufferLength member.

Status block

The USB stack sets Irp->IoStatus.Status to STATUS_SUCCESS if the request is successful. Otherwise, the USB stack sets Status to the appropriate error condition, such as STATUS_INVALID_PARAMETER or STATUS_INSUFFICIENT_RESOURCES.

Remarks

To get the driver key name in the registry, you must perform the following tasks:

  1. Declare a variable of the type USB_HCD_DRIVERKEY_NAME.
  2. Send an IOCTL_GET_HCD_DRIVERKEY_NAME request by specifying the address and size of the variable in the output parameters. On return, the ActualLength member of USB_HCD_DRIVERKEY_NAME contains the length required to allocate a buffer to hold a USB_HCD_DRIVERKEY_NAME that is populated with the driver key name.
  3. Allocate memory for a buffer to hold a USB_HCD_DRIVERKEY_NAME structure. The size of the buffer must be the received ActualLength value.
  4. Send an IOCTL_GET_HCD_DRIVERKEY_NAME request by passing a pointer to the allocated buffer and its size in the output parameters. On return, the DriverKeyName member of USB_HCD_DRIVERKEY_NAME is a null-terminated Unicode string that contains the name of the driver key associated with the host controller driver.

The following example code shows how to send the IOCTL_GET_HCD_DRIVERKEY_NAME I/O control request.



/*++

Routine Description:

This routine prints the name of the driver key associated with
the specified host controller driver.

Arguments:

HCD - Handle for host controller driver.

Return Value: Boolean that indicates success or failure.

--*/

BOOL GetHCDDriverKeyName (HANDLE  HCD)
{
    BOOL                    success;
    ULONG                   nBytes;
    USB_HCD_DRIVERKEY_NAME  driverKeyName;
    PUSB_HCD_DRIVERKEY_NAME driverKeyNameW;

    driverKeyNameW = NULL;

    // 1. Get the length of the name of the driver key.
    success = DeviceIoControl(HCD,
        IOCTL_GET_HCD_DRIVERKEY_NAME,
        NULL,
        0,
        &driverKeyName,
        sizeof(driverKeyName),
        &nBytes,
        NULL);

    if (!success) 
    {
        printf("First IOCTL_GET_HCD_DRIVERKEY_NAME request failed\n");
        goto GetHCDDriverKeyNameDone;
    }

    //2. Get the length of the driver key name.
    nBytes = driverKeyName.ActualLength;

    if (nBytes <= sizeof(driverKeyName)) 
    {
        printf("Incorrect length received by IOCTL_GET_HCD_DRIVERKEY_NAME.\n");
        goto GetHCDDriverKeyNameDone;
    }

    // 3. Allocate memory for a USB_HCD_DRIVERKEY_NAME
    //    to hold the driver key name.
    driverKeyNameW = (PUSB_HCD_DRIVERKEY_NAME) malloc(nBytes);

    if (driverKeyNameW == NULL) 
    {
        printf("Failed to allocate memory.\n");
        goto GetHCDDriverKeyNameDone;
    }

    // Get the name of the driver key of the device attached to
    // the specified port.
    success = DeviceIoControl(HCD,
        IOCTL_GET_HCD_DRIVERKEY_NAME,
        NULL,
        0,
        driverKeyNameW,
        nBytes,
        &nBytes,
        NULL);

    if (!success) 
    {
        printf("Second IOCTL_GET_HCD_DRIVERKEY_NAME request failed.\n");
        goto GetHCDDriverKeyNameDone;
    }

    // print the driver key name. 
    printf("Driver Key Name: %s.\n", driverKeyNameW->DriverKeyName);


GetHCDDriverKeyNameDone:

    // Cleanup.
    // Free the allocated memory for USB_HCD_DRIVERKEY_NAME.

    if (driverKeyNameW != NULL) 
    {
        free(driverKeyNameW);
        driverKeyNameW = NULL;
    }

    return success;
}



Requirements

Header

Usbioctl.h (include Usbioctl.h)

See also

USB_HCD_DRIVERKEY_NAME

 

 

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