SilcAsyncOperation
    silc_socket_tcp_stream_create(SilcSocket sock, SilcBool lookup,
                                  SilcBool require_fqdn,
                                  SilcSchedule schedule,
                                  SilcSocketStreamCallback callback,
                                  void *context);

    Creates TCP socket stream of the TCP connection indicated by `sock'.
    The stream can be destroyed by calling the silc_stream_destroy.  Data
    can be sent and received from the stream by calling silc_stream_write
    and silc_stream_read.  The creation process is asynchronous since
    socket connection information, such as hostname and IP address are
    resolved, so SilcAsyncOperation is returned which can be used to cancel
    the creation process.  The `callback' will be called to return the
    created socket stream.

    If the `lookup' is TRUE then this will perform IP and hostname lookup
    for the socket.  If the `require_fqdn' is TRUE then the socket must
    have valid hostname and IP address, otherwise the stream creation will
    fail.  If it is FALSE then only valid IP address is required.  Note that,
    if the `lookup' is FALSE then the hostname, IP and port information
    will not be available from the socket stream.  In that case this will
    also return NULL as the `callback' is called immediately.

    If the silc_stream_set_notifier is called the stream is set to
    non-blocking mode.