affect how the message is sent.  See the C{MSG_}
        constants in the sendmsg(2) manual page. By default no flags are set.
    @type flags: L{int}

    @return: A named 3-tuple of the bytes received using the datagram/stream
        mechanism, a L{list} of L{tuple}s giving ancillary received data, and
        flags as an L{int} describing the data received.
    r