/* include udp_server */#include	"unp.h"intudp_server(const char *host, const char *serv, socklen_t *addrlenp){	int				sockfd, n;	struct addrinfo	hints, *res, *ressave;	bzero(&hints, sizeof(struct addrinfo));	hints.ai_flags = AI_PASSIVE;	hints.ai_family = AF_UNSPEC;	hints.ai_socktype = SOCK_DGRAM;	if ( (n = getaddrinfo(host, serv, &hints, &res)) != 0)		err_quit("udp_server error for %s, %s: %s",				 host, serv, gai_strerror(n));	ressave = res;	do {		sockfd = socket(res->ai_family, res->ai_socktype, res->ai_protocol);		if (sockfd < 0)			continue;		/* error, try next one */		if (bind(sockfd, res->ai_addr, res->ai_addrlen) == 0)			break;			/* success */		Close(sockfd);		/* bind error, close and try next one */	} while ( (res = res->ai_next) != NULL);	if (res == NULL)	/* errno from final socket() or bind() */		err_sys("udp_server error for %s, %s", host, serv);	if (addrlenp)		*addrlenp = res->ai_addrlen;	/* return size of protocol address */	freeaddrinfo(ressave);	return(sockfd);}/* end udp_server */intUdp_server(const char *host, const char *serv, socklen_t *addrlenp){	return(udp_server(host, serv, addrlenp));}