+ struct servent *se;
+ struct sockaddr_in *sin = (struct sockaddr_in *)&local_addr;
+ (void) bindresvport(sock, sin);
+ /* try to avoid known ports */
+ se = getservbyport(sin->sin_port, "udp");
+ if (se && retry_cnt < 100) {
+ retry_cnt++;
+ close(sock);
+ goto retry;
+ }