listati/sockbind.c

   1 int sockbind(char *host, char *serv, int prot, int type)
   2 {
   3     struct addrinfo hint, *addr, *save;
   4     int res;
   5     int sock;
   6     char buf[INET6_ADDRSTRLEN];
   7     memset(&hint, 0, sizeof(struct addrinfo));
   8     hint.ai_flags = AI_PASSIVE;            /* address for binding */
   9     hint.ai_family = PF_UNSPEC;            /* generic address (IPv4 or IPv6) */
  10     hint.ai_protocol = prot;               /* protocol */
  11     hint.ai_socktype = type;               /* socket type */
  12     res = getaddrinfo(host, serv, &hint, &addr);   /* calling getaddrinfo */
  13     if (res != 0) {                                /* on error exit */
  14         fprintf(stderr, "sockbind: resolution failed:");
  15         fprintf(stderr, " %s\n", gai_strerror(res));
  16         errno = 0;                         /* clear errno */
  17         return -1;
  18     }
  19     save = addr;                           /* saving for freeaddrinfo */
  20     while (addr != NULL) {                 /* loop on possible addresses */
  21         sock = socket(addr->ai_family, addr->ai_socktype, addr->ai_protocol);
  22         if (sock < 0) {                    /* on error */
  23             if (addr->ai_next != NULL) {   /* if other addresses */
  24                 addr=addr->ai_next;        /* take next */
  25                 continue;                  /* restart cycle */
  26             } else {                       /* else stop */
  27                 perror("sockbind: cannot create socket");
  28                 return sock;
  29             }
  30         }
  31         if ( (res = bind(sock, addr->ai_addr, addr->ai_addrlen)) < 0) {
  32             if (addr->ai_next != NULL) {   /* if other addresses */
  33                 addr=addr->ai_next;        /* take next */
  34                 close(sock);               /* close socket */
  35                 continue;                  /* restart cycle */
  36             } else {                       /* else stop */
  37                 perror("sockbind: cannot connect");
  38                 close(sock);
  39                 return res;
  40             }
  41         } else break;                      /* ok, we are binded! */
  42     }
  43     freeaddrinfo(save);                    /* done, release memory */
  44     return sock;
  45 }