+#endif
+ else {
+ len_and_sockaddr *lsa;
+#if ENABLE_FEATURE_IPV6
+ char *prefix;
+ int prefix_len = 0;
+ prefix = strchr(host, '/');
+ if (prefix) {
+ prefix_len = xatou_range(prefix + 1, 0, 128);
+ *prefix = '\0';
+ }
+ resolve:
+#endif
+ lsa = xhost2sockaddr(host, 0);
+#if ENABLE_FEATURE_IPV6
+ if (lsa->u.sa.sa_family != AF_INET6 && prefix) {
+/* TODO: we do not support "ifconfig eth0 up 1.2.3.4/17".
+ * For now, just make it fail instead of silently ignoring "/17" part:
+ */
+ *prefix = '/';
+ goto resolve;
+ }
+ if (lsa->u.sa.sa_family == AF_INET6) {
+ int sockfd6;
+ struct in6_ifreq ifr6;
+
+ sockfd6 = xsocket(AF_INET6, SOCK_DGRAM, 0);
+ xioctl(sockfd6, SIOCGIFINDEX, &ifr);
+ ifr6.ifr6_ifindex = ifr.ifr_ifindex;
+ ifr6.ifr6_prefixlen = prefix_len;
+ memcpy(&ifr6.ifr6_addr,
+ &lsa->u.sin6.sin6_addr,
+ sizeof(struct in6_addr));
+ ioctl_or_perror_and_die(sockfd6, a1op->selector, &ifr6, "SIOC%s", a1op->name);
+ if (ENABLE_FEATURE_CLEAN_UP)
+ free(lsa);
+ continue;
+ }
+#endif
+ sai.sin_addr = lsa->u.sin.sin_addr;
+ if (ENABLE_FEATURE_CLEAN_UP)
+ free(lsa);
+ }
+#if ENABLE_FEATURE_IFCONFIG_BROADCAST_PLUS
+ if (mask & A_HOSTNAME)
+ sai_hostname = sai.sin_addr.s_addr;
+ if (mask & A_NETMASK)
+ sai_netmask = sai.sin_addr.s_addr;
+#endif