int dtls1_listen(SSL *s, struct sockaddr *client)
 {
     int ret;
 
    /* Ensure there is no state left over from a previous invocation */
    SSL_clear(s);

     SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
     s->d1->listen = 1;

    (void)BIO_dgram_get_peer(SSL_get_rbio(s), client);
    return 1;
}

Unknown