ndp: replay on-link routes instead of address assignments

diff --git a/src/ndp.c b/src/ndp.c
index 5fc95dd88d787434d79fb0cd3f0dab4684042e94..027e9ab53e8d117bd766fda968843230c0e85734 100644 (file)
--- a/src/ndp.c
+++ b/src/ndp.c
@@ -332,43 +332,54 @@ static void handle_rtnetlink(_unused void *addr, void *data, size_t len,
 
        for (struct nlmsghdr *nh = data; NLMSG_OK(nh, len);
                        nh = NLMSG_NEXT(nh, len)) {
+               struct ndmsg *ndm = NLMSG_DATA(nh);
                struct rtmsg *rtm = NLMSG_DATA(nh);
-               if ((nh->nlmsg_type == RTM_NEWROUTE ||
-                               nh->nlmsg_type == RTM_DELROUTE) &&
-                               rtm->rtm_dst_len == 0)
-                       raise(SIGUSR1); // Inform about a change in default route
 
-               struct ndmsg *ndm = NLMSG_DATA(nh);
-               struct ifaddrmsg *ifa = NLMSG_DATA(nh);
-               if (nh->nlmsg_type != RTM_NEWNEIGH
-                               && nh->nlmsg_type != RTM_DELNEIGH
-                               && nh->nlmsg_type != RTM_NEWADDR
-                               && nh->nlmsg_type != RTM_DELADDR)
-                       continue; // Unrelated message type
                bool is_addr = (nh->nlmsg_type == RTM_NEWADDR
                                || nh->nlmsg_type == RTM_DELADDR);
+               bool is_route = (nh->nlmsg_type == RTM_NEWROUTE
+                               || nh->nlmsg_type == RTM_DELROUTE);
+               bool is_neigh = (nh->nlmsg_type == RTM_NEWNEIGH
+                               || nh->nlmsg_type == RTM_DELNEIGH);
 
                // Family and ifindex are on the same offset for NEIGH and ADDR
-               if (NLMSG_PAYLOAD(nh, 0) < sizeof(*ndm)
+               if ((!is_addr && !is_route && !is_neigh)
+                               || NLMSG_PAYLOAD(nh, 0) < sizeof(*ndm)
                                || ndm->ndm_family != AF_INET6)
-                       continue; //
+                       continue;
 
-               // Lookup interface
-               struct interface *iface;
-               if (!(iface = odhcpd_get_interface_by_index(ndm->ndm_ifindex)))
+               // Inform about a change in default route
+               if (is_route && rtm->rtm_dst_len == 0)
+                       raise(SIGUSR1);
+               else if (is_route && rtm->rtm_dst_len == 128)
                        continue;
 
                // Data to retrieve
-               size_t rta_offset = (is_addr) ? sizeof(*ifa) : sizeof(*ndm);
-               uint16_t atype = (is_addr) ? IFA_ADDRESS : NDA_DST;
+               size_t rta_offset = (is_route) ? sizeof(*rtm) : (is_addr) ?
+                               sizeof(*ifa) : sizeof(*ndm);
+               uint16_t atype = (is_route) ? RTA_DST : (is_addr) ? IFA_ADDRESS : NDA_DST;
                ssize_t alen = NLMSG_PAYLOAD(nh, rta_offset);
                struct in6_addr *addr = NULL;
+               int *ifindex = (!is_route) ? &ndm->ndm_ifindex : NULL;
 
                for (struct rtattr *rta = (void*)(((uint8_t*)ndm) + rta_offset);
-                               RTA_OK(rta, alen); rta = RTA_NEXT(rta, alen))
+                               RTA_OK(rta, alen); rta = RTA_NEXT(rta, alen)) {
                        if (rta->rta_type == atype &&
-                                       RTA_PAYLOAD(rta) >= sizeof(*addr))
+                                       RTA_PAYLOAD(rta) >= sizeof(*addr)) {
                                addr = RTA_DATA(rta);
+                       } else if (is_route && rta->rta_type == RTA_OIF &&
+                                       RTA_PAYLOAD(rta) == sizeof(int)) {
+                               ifindex = (int*)RTA_DATA(rta);
+                       } else if (is_route && rta->rta_type == RTA_GATEWAY) {
+                               ifindex = NULL;
+                               break;
+                       }
+               }
+
+               // Lookup interface
+               struct interface *iface = ifindex ? odhcpd_get_interface_by_index(*ifindex) : NULL;
+               if (!iface)
+                       continue;
 
                // Keep-alive neighbor entries for RA sending
                if (nh->nlmsg_type == RTM_DELNEIGH && !(ndm->ndm_state & NUD_FAILED) &&
@@ -389,7 +400,7 @@ static void handle_rtnetlink(_unused void *addr, void *data, size_t len,
                                (NUD_REACHABLE | NUD_STALE | NUD_DELAY | NUD_PROBE
                                                | NUD_PERMANENT | NUD_NOARP)));
 
-               if (iface->ndp == RELAYD_RELAY) {
+               if (iface->ndp == RELAYD_RELAY && !is_route) {
                        // Replay change to all neighbor cache
                        struct {
                                struct nlmsghdr nh;
@@ -468,18 +479,18 @@ static void handle_rtnetlink(_unused void *addr, void *data, size_t len,
 
                        if (iface->dhcpv6 == RELAYD_SERVER)
                                iface->ia_reconf = true;
-
+               } else if (is_route) {
                        if (iface->ndp == RELAYD_RELAY && iface->master) {
-                               // Replay address changes on all slave interfaces
+                               // Replay on-link route changes on all slave interfaces
                                nh->nlmsg_flags = NLM_F_REQUEST;
 
-                               if (nh->nlmsg_type == RTM_NEWADDR)
+                               if (nh->nlmsg_type == RTM_NEWROUTE)
                                        nh->nlmsg_flags |= NLM_F_CREATE | NLM_F_REPLACE;
 
                                struct interface *c;
                                list_for_each_entry(c, &interfaces, head) {
                                        if (c->ndp == RELAYD_RELAY && !c->master) {
-                                               ifa->ifa_index = c->ifindex;
+                                               *ifindex = c->ifindex;
                                                send(rtnl_event.uloop.fd, nh, nh->nlmsg_len, MSG_DONTWAIT);
                                        }
                                }