IOCTL_SEND_USB_REQUEST IOCTL (usbscan.h)
Sends a vendor-defined request to a USB device, using the control pipe, and optionally sends or receives additional data.
Major code
Input buffer
Pointer to an IO_BLOCK_EX structure.
Input buffer length
Size of the input buffer.
Output buffer
Pointer to the same buffer the pbyData member of the IO_BLOCK_EX structure identified, or NULL if a data transfer is not being requested.
Output buffer length
Size of the output buffer, or zero if a data transfer is not being requested.
Status block
Irp->IoStatus.Status is set to STATUS_SUCCESS if the request is successful. Otherwise, Status to the appropriate error condition as a NTSTATUS code.
Remarks
DeviceIoControl Parameters
When the DeviceloControl function is called with the IOCTL_SEND_USB_REQUEST control code, the caller must specify the address of an IO_BLOCK_EX structure as the function's lpInBuffer parameter. The type of request specified with this I/O control code is device-specific and vendor-defined, as are the type and size of any information that might be sent or received.
The following table shows how input arguments should be specified.
| Argument | Read Operation | Write Operation | No Data Transfer |
|---|---|---|---|
| lpInBuffer | IO_BLOCK_EX pointer. | IO_BLOCK_EX pointer. | IO_BLOCK_EX pointer. |
| lpOutBuffer | Pointer to buffer that will receive data to be read. | Pointer to buffer containing data to be written. | NULL |
| lpOutBufferSize | Size of buffer. | Size of buffer. | Zero |
| bRequest member of IO_BLOCK_EX structure | Device-specific request code. | Device-specific request code. | Device-specific request code. |
| pbyData member of IO_BLOCK_EX structure | Same pointer as lpOutBuffer. | Same pointer as lpOutBuffer. | NULL |
| uLength member of IO_BLOCK_EX structure | Same value as lpOutBufferSize. | Same value as lpOutBufferSize. | Zero |
| fTransferDirectionIn member of IO_BLOCK_EX structure | TRUE | FALSE | FALSE |
The bmRequestType member of the IO_BLOCK_EX structure is not used with IOCTL_SEND_USB_REQUEST.
Using the IO_BLOCK_EX structure contents, the kernel-mode driver creates a URB that contains a URB_CONTROL_VENDOR_OR_CLASS_REQUEST structure.
The following table indicates the values assigned to _URB_CONTROL_VENDOR_OR_CLASS_REQUEST structure members.
| Structure Member | Value Assigned |
|---|---|
| TransferFlags | 0 |
| TransferBufferLength | pIoBlockEx->uLength |
| TransferBuffer | lpOutBuffer (read) or pIoBlockEx->pbyData (write) |
| TransferBufferMDL | NULL |
| RequestTypeReservedBits | 0xC0 (read) or 0x40 (write) |
| Request | pIoBlockEx->bRequest |
| Value | (SHORT)pIoBlockEx->uOffset |
| Index | pIoBlockEx->uIndex |
For more information, see Accessing Kernel-Mode Drivers for Still Image Devices.
Requirements
| Requirement | Value |
|---|---|
| Header | usbscan.h (include Usbscan.h) |