router: don't announce as default router if we aren't

[project/odhcpd.git] / src / odhcpd.c

diff --git a/src/odhcpd.c b/src/odhcpd.c
index 5774a4f..9c7f27c 100644 (file)
--- a/src/odhcpd.c
+++ b/src/odhcpd.c
@@ -254,24 +254,21 @@ ssize_t odhcpd_get_interface_addresses(int ifindex,
        return ret;
 }
 
-int odhcpd_get_preferred_interface_address(int ifindex, struct in6_addr *addr)
+int odhcpd_get_linklocal_interface_address(int ifindex, struct in6_addr *lladdr)
 {
-       struct odhcpd_ipaddr ipaddrs[8];
-       ssize_t ip_cnt = odhcpd_get_interface_addresses(ifindex, ipaddrs, ARRAY_SIZE(ipaddrs));
-       uint32_t preferred = 0;
-       int ret = 0;
-
-       for (ssize_t i = 0; i < ip_cnt; i++) {
-               struct odhcpd_ipaddr *ipaddr = &ipaddrs[i];
-
-               if (ipaddr->preferred > preferred || !preferred) {
-                       preferred = ipaddr->preferred;
-                       *addr = ipaddr->addr;
-                       ret = 1;
+               int status = -1;
+               struct sockaddr_in6 addr = {AF_INET6, 0, 0, ALL_IPV6_ROUTERS, ifindex};
+               socklen_t alen = sizeof(addr);
+               int sock = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6);
+
+               if (!connect(sock, (struct sockaddr*)&addr, sizeof(addr)) &&
+                               !getsockname(sock, (struct sockaddr*)&addr, &alen)) {
+                       *lladdr = addr.sin6_addr;
+                       status = 0;
                }
-       }
 
-       return ret;
+               close(sock);
+               return status;
 }
 
 void odhcpd_setup_route(const struct in6_addr *addr, int prefixlen,