3.3.5.2.2.7 Sending an IOControl Request Message
The structure and fields of the IOControl Request message are described in section 2.2.2.3.7.
This message MUST be sent only after the CreateFile request-response sequence has been sent, establishing a file handle for I/O on this connection. The server MUST generate a RequestId for this request and the server MUST pass along the rest of the IOControl parameters. The server also stores all necessary information required to complete the request (for example, the location of a variable to store the result), and associates this information with the RequestId.