ndp: replay on-link routes instead of address assignments
[project/odhcpd.git] / src / ndp.c
index c1ac063..027e9ab 100644 (file)
--- a/src/ndp.c
+++ b/src/ndp.c
@@ -73,16 +73,6 @@ int init_ndp(void)
        setsockopt(rtnl_event.uloop.fd, SOL_NETLINK,
                        NETLINK_ADD_MEMBERSHIP, &group, sizeof(group));
 
-       // Synthesize initial address events
-       struct {
-               struct nlmsghdr nh;
-               struct ifaddrmsg ifa;
-       } req2 = {
-               {sizeof(req2), RTM_GETADDR, NLM_F_REQUEST | NLM_F_DUMP,
-                               ++rtnl_seqid, 0},
-               {.ifa_family = AF_INET6}
-       };
-       send(rtnl_event.uloop.fd, &req2, sizeof(req2), MSG_DONTWAIT);
        odhcpd_register(&rtnl_event);
 
        // Open ICMPv6 socket
@@ -125,6 +115,7 @@ static void dump_neigh_table(bool proxy)
                {.ndm_family = AF_INET6, .ndm_flags = (proxy) ? NTF_PROXY : 0}
        };
        send(rtnl_event.uloop.fd, &req, sizeof(req), MSG_DONTWAIT);
+       odhcpd_process(&rtnl_event);
 }
 
 
@@ -135,17 +126,34 @@ int setup_ndp_interface(struct interface *iface, bool enable)
        int procfd = open(procbuf, O_WRONLY);
        bool dump_neigh = false;
 
-       if (iface->ndp_event.uloop.fd >= 0) {
+       if (iface->ndp_event.uloop.fd > 0) {
                uloop_fd_delete(&iface->ndp_event.uloop);
                close(iface->ndp_event.uloop.fd);
                iface->ndp_event.uloop.fd = -1;
 
-               write(procfd, "0\n", 2);
+               if (!enable || iface->ndp != RELAYD_RELAY)
+                       if (write(procfd, "0\n", 2) < 0) {}
+
                dump_neigh = true;
        }
 
+       if (enable && (iface->ra == RELAYD_SERVER ||
+                       iface->dhcpv6 == RELAYD_SERVER || iface->ndp == RELAYD_RELAY)) {
+               // Synthesize initial address events
+               struct {
+                       struct nlmsghdr nh;
+                       struct ifaddrmsg ifa;
+               } req2 = {
+                       {sizeof(req2), RTM_GETADDR, NLM_F_REQUEST | NLM_F_DUMP,
+                                       ++rtnl_seqid, 0},
+                       {.ifa_family = AF_INET6, .ifa_index = iface->ifindex}
+               };
+               send(rtnl_event.uloop.fd, &req2, sizeof(req2), MSG_DONTWAIT);
+       }
+
        if (enable && iface->ndp == RELAYD_RELAY) {
-               write(procfd, "1\n", 2);
+               if (write(procfd, "1\n", 2) < 0) {}
+               close(procfd);
 
                int sock = socket(AF_PACKET, SOCK_DGRAM | SOCK_CLOEXEC, htons(ETH_P_IPV6));
                if (sock < 0) {
@@ -169,6 +177,10 @@ int setup_ndp_interface(struct interface *iface, bool enable)
                        .sll_family = AF_PACKET,
                        .sll_ifindex = iface->ifindex,
                        .sll_protocol = htons(ETH_P_IPV6),
+                       .sll_hatype = 0,
+                       .sll_pkttype = 0,
+                       .sll_halen = 0,
+                       .sll_addr = {0},
                };
                bind(sock, (struct sockaddr*)&ll, sizeof(ll));
 
@@ -184,8 +196,9 @@ int setup_ndp_interface(struct interface *iface, bool enable)
                        dump_neigh_table(false);
                else
                        dump_neigh = false;
+       } else {
+               close(procfd);
        }
-       close(procfd);
 
        if (dump_neigh)
                dump_neigh_table(true);
@@ -199,7 +212,7 @@ int setup_ndp_interface(struct interface *iface, bool enable)
 static ssize_t ping6(struct in6_addr *addr,
                const struct interface *iface)
 {
-       struct sockaddr_in6 dest = {AF_INET6, 0, 0, *addr, 0};
+       struct sockaddr_in6 dest = {AF_INET6, 0, 0, *addr, iface->ifindex};
        struct icmp6_hdr echo = {.icmp6_type = ICMP6_ECHO_REQUEST};
        struct iovec iov = {&echo, sizeof(echo)};
 
@@ -246,7 +259,7 @@ static void handle_solicit(void *addr, void *data, size_t len,
        struct interface *c;
        list_for_each_entry(c, &interfaces, head)
                if (iface->ndp == RELAYD_RELAY && iface != c &&
-                               (!ns_is_dad || !c->external == false))
+                               (ns_is_dad || !c->external))
                        ping6(&req->nd_ns_target, c);
 }
 
@@ -284,7 +297,7 @@ void odhcpd_setup_route(const struct in6_addr *addr, int prefixlen,
        if (add) {
                req.nh.nlmsg_type = RTM_NEWROUTE;
                req.nh.nlmsg_flags |= (NLM_F_CREATE | NLM_F_REPLACE);
-               req.rtm.rtm_protocol = RTPROT_BOOT;
+               req.rtm.rtm_protocol = RTPROT_STATIC;
                req.rtm.rtm_scope = (gw) ? RT_SCOPE_UNIVERSE : RT_SCOPE_LINK;
                req.rtm.rtm_type = RTN_UNICAST;
        } else {
@@ -292,23 +305,20 @@ void odhcpd_setup_route(const struct in6_addr *addr, int prefixlen,
                req.rtm.rtm_scope = RT_SCOPE_NOWHERE;
        }
 
-       size_t reqlen = (gw) ? sizeof(req) : offsetof(struct req, rta_gw);
-       send(rtnl_event.uloop.fd, &req, reqlen, MSG_DONTWAIT);
+       req.nh.nlmsg_len = (gw) ? sizeof(req) : offsetof(struct req, rta_gw);
+       send(rtnl_event.uloop.fd, &req, req.nh.nlmsg_len, MSG_DONTWAIT);
 }
 
 // Use rtnetlink to modify kernel routes
-static void setup_route(struct in6_addr *addr, struct interface *iface,
-               bool add)
+static void setup_route(struct in6_addr *addr, struct interface *iface, bool add)
 {
        char namebuf[INET6_ADDRSTRLEN];
        inet_ntop(AF_INET6, addr, namebuf, sizeof(namebuf));
-       syslog(LOG_NOTICE, "%s about %s on %s", (add) ? "Learned" : "Forgot",
-                       namebuf, (iface) ? iface->ifname : "<pending>");
+       syslog(LOG_NOTICE, "%s about %s on %s",
+                       (add) ? "Learned" : "Forgot", namebuf, iface->ifname);
 
-       if (!iface || !iface->learn_routes)
-               return;
-
-       odhcpd_setup_route(addr, 128, iface, NULL, add);
+       if (iface->learn_routes)
+               odhcpd_setup_route(addr, 128, iface, NULL, add);
 }
 
 
@@ -322,43 +332,59 @@ 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) &&
+                               addr && IN6_IS_ADDR_LINKLOCAL(addr) && iface->ra == RELAYD_SERVER)
+                       ping6(addr, iface);
 
                // Address not specified or unrelated
                if (!addr || IN6_IS_ADDR_LINKLOCAL(addr) ||
@@ -374,7 +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;
@@ -394,6 +420,7 @@ static void handle_rtnetlink(_unused void *addr, void *data, size_t len,
                                if (nh->nlmsg_type == RTM_NEWNEIGH) {
                                        req.ndm.ndm_ifindex = iface->ifindex;
                                        send(rtnl_event.uloop.fd, &req, sizeof(req), MSG_DONTWAIT);
+                                       setup_route(addr, iface, false);
                                        dump_neigh = true;
                                }
                        } else if (add) {
@@ -452,18 +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);
                                        }
                                }