// Requests out-of-band data. The significance and semantics of out-of-band data are protocol-specific.
// MSG_PEEK
// Peeks at the incoming message.
// MSG_WAITALL
// Requests that the function block until the full amount of data requested can be returned. The function may return a smaller amount of data if a signal is caught, if the connection is terminated, if MSG_PEEK was specified, or if an error is pending for the socket.