int sockconn(char *host, char *serv, int prot, int type) { struct addrinfo hint, *addr, *save; int res; int sock; memset(&hint, 0, sizeof(struct addrinfo)); hint.ai_family = PF_UNSPEC; /* generic address (IPv4 or IPv6) */ hint.ai_protocol = prot; /* protocol */ hint.ai_socktype = type; /* socket type */ res = getaddrinfo(host, serv, &hint, &addr); /* calling getaddrinfo */ if (res != 0) { /* on error exit */ fprintf(stderr, "sockconn: resolution failed:"); fprintf(stderr, " %s\n", gai_strerror(res)); errno = 0; /* clear errno */ return -1; } save = addr; while (addr != NULL) { /* loop on possible addresses */ sock = socket(addr->ai_family, addr->ai_socktype, addr->ai_protocol); if (sock < 0) { /* on error */ if (addr->ai_next != NULL) { /* if other addresses */ addr=addr->ai_next; /* take next */ continue; /* restart cycle */ } else { /* else stop */ perror("sockconn: cannot create socket"); return sock; } } if ( (res = connect(sock, addr->ai_addr, addr->ai_addrlen) < 0)) { if (addr->ai_next != NULL) { /* if other addresses */ addr=addr->ai_next; /* take next */ close(sock); /* close socket */ continue; /* restart cycle */ } else { /* else stop */ perror("sockconn: cannot connect"); close(sock); return res; } } else break; /* ok, we are connected! */ } freeaddrinfo(save); /* done, release memory */ return sock; }