FSCTL_GET_WOF_VERSION control code

The FSCTL_GET_WOF_VERSION I/O control code (IOCTL) is used to query the version of the driver used to support a particular provider.

To perform this operation, call FltFsControlFile or ZwFsControlFile with the following parameters.

BOOL
   WINAPI
   DeviceIoControl( (HANDLE)       hDevice,         // handle to device
                    (DWORD)        FSCTL_GET_WOF_VERSION, // dwIoControlCode
                    (LPDWORD)      lpInBuffer,      // input buffer
                    (DWORD)        nInBufferSize,   // size of input buffer
                    (LPDWORD)      lpOutBuffer,     // output buffer
                    (DWORD)        nOutBufferSize,  // size of output buffer
                    (LPDWORD)      lpBytesReturned, // number of bytes returned
                    (LPOVERLAPPED) lpOverlapped );  // OVERLAPPED structure

Parameters

• hDevice [in]: A handle to the device. To obtain a device handle, call the CreateFile function or similar API.

• dwIoControlCode [in]: The control code for the operation. Use FSCTL_GET_WOF_VERSION for this operation.

• lpInBuffer: The input buffer for the operation. This is a pointer to a WOF_EXTERNAL_INFO structure.

• nInBufferSize [in]: The size, in bytes, of the input buffer. This should be sizeof(WOF_EXTERNAL_INFO).

• lpOutBuffer [out]: The output buffer for the operation. This is a pointer to a WOF_VERSION_INFO structure.

• nOutBufferSize [in]: The size, in bytes, of the output buffer. This should be sizeof(WOF_VERSION_INFO).

• lpBytesReturned [out]: A pointer to a variable that receives the size of the data stored in the output buffer, in bytes.

  If the output buffer is too small, the call fails, GetLastError returns ERROR_INSUFFICIENT_BUFFER, and lpBytesReturned is zero.

  If lpOverlapped is NULL, lpBytesReturned cannot be NULL. Even when an operation returns no output data and lpOutBuffer is NULL, DeviceIoControl makes use of lpBytesReturned. After such an operation, the value of lpBytesReturned is meaningless.

  If lpOverlapped is not NULL, lpBytesReturned can be NULL. If this parameter is not NULL and the operation returns data, lpBytesReturned is meaningless until the overlapped operation has completed. To retrieve the number of bytes returned, call GetOverlappedResult. If the hDevice parameter is associated with an I/O completion port, you can retrieve the number of bytes returned by calling GetQueuedCompletionStatus.

• lpOverlapped [in]: A pointer to an OVERLAPPED structure.

  If hDevice was opened without specifying FILE_FLAG_OVERLAPPED, lpOverlapped is ignored.

  If hDevice was opened with the FILE_FLAG_OVERLAPPED flag, the operation is performed as an overlapped (asynchronous) operation. In this case, lpOverlapped must point to a valid OVERLAPPED structure that contains a handle to an event object. Otherwise, the function fails in unpredictable ways.

  For overlapped operations, DeviceIoControl returns immediately, and the event object is signaled when the operation has been completed. Otherwise, the function does not return until the operation has been completed or an error occurs.

Status block

If the operation completes successfully, DeviceIoControl returns a nonzero value.

If the operation fails or is pending, DeviceIoControl returns zero. To get extended error information, call GetLastError.

Requirements