int silc_packet_send(SilcSocketConnection sock, bool force_send);

    Actually sends the packet. This flushes the connections outgoing data
    buffer. If data is sent directly to the network this returns the bytes
    written, if error occured this returns -1 and if the data could not
    be written directly to the network at this time this returns -2, in
    which case the data should be queued by the caller and sent at some
    later time. If `force_send' is TRUE this attempts to write the data
    directly to the network, if FALSE, this returns -2.