cmake: enforce additonal compiler checks
[project/odhcpd.git] / src / ndp.c
index 366522b63833e1dd3f65ff9e96b9b2e8b7b896fe..dfbb1115c2126cf67bdb7c08674a5355fa84750c 100644 (file)
--- a/src/ndp.c
+++ b/src/ndp.c
 #include <netinet/icmp6.h>
 #include <netpacket/packet.h>
 
-#include <linux/rtnetlink.h>
 #include <linux/filter.h>
-
-#include <netlink/msg.h>
-#include <netlink/socket.h>
-#include <netlink/attr.h>
+#include <linux/neighbour.h>
 
 #include "dhcpv6.h"
 #include "odhcpd.h"
 
-struct event_socket {
-       struct odhcpd_event ev;
-       struct nl_sock *sock;
-       int sock_bufsize;
-};
 
+static void ndp_netevent_cb(unsigned long event, struct netevent_handler_info *info);
+static void setup_route(struct in6_addr *addr, struct interface *iface, bool add);
+static void setup_addr_for_relaying(struct in6_addr *addr, struct interface *iface, bool add);
 static void handle_solicit(void *addr, void *data, size_t len,
                struct interface *iface, void *dest);
-static void handle_rtnl_event(struct odhcpd_event *ev);
-static int cb_rtnl_valid(struct nl_msg *msg, void *arg);
-static void catch_rtnl_err(struct odhcpd_event *e, int error);
-
-static int addr6_dump_rqs = 0;
-static int ping_socket = -1;
-static struct event_socket rtnl_event = {
-       .ev = {
-               .uloop = {.fd = - 1, },
-               .handle_dgram = NULL,
-               .handle_error = catch_rtnl_err,
-               .recv_msgs = handle_rtnl_event,
-       },
-       .sock = NULL,
-       .sock_bufsize = 133120,
-};
 
-// Filter ICMPv6 messages of type neighbor soliciation
+/* Filter ICMPv6 messages of type neighbor soliciation */
 static struct sock_filter bpf[] = {
        BPF_STMT(BPF_LD | BPF_B | BPF_ABS, offsetof(struct ip6_hdr, ip6_nxt)),
        BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, IPPROTO_ICMPV6, 0, 3),
@@ -72,122 +50,29 @@ static struct sock_filter bpf[] = {
        BPF_STMT(BPF_RET | BPF_K, 0),
 };
 static const struct sock_fprog bpf_prog = {sizeof(bpf) / sizeof(*bpf), bpf};
+static struct netevent_handler ndp_netevent_handler = { .cb = ndp_netevent_cb, };
 
-
-// Initialize NDP-proxy
-int init_ndp(void)
+/* Initialize NDP-proxy */
+int ndp_init(void)
 {
-       int val = 2;
-
-       rtnl_event.sock = odhcpd_create_nl_socket(NETLINK_ROUTE);
-       if (!rtnl_event.sock)
-               goto err;
-
-       rtnl_event.ev.uloop.fd = nl_socket_get_fd(rtnl_event.sock);
-
-       if (nl_socket_set_buffer_size(rtnl_event.sock, rtnl_event.sock_bufsize, 0))
-               goto err;
-
-       nl_socket_disable_seq_check(rtnl_event.sock);
-
-       nl_socket_modify_cb(rtnl_event.sock, NL_CB_VALID, NL_CB_CUSTOM,
-                       cb_rtnl_valid, NULL);
-
-       // Receive IPv6 address, IPv6 routes and neighbor events
-       if (nl_socket_add_memberships(rtnl_event.sock, RTNLGRP_IPV6_IFADDR,
-                               RTNLGRP_IPV6_ROUTE, RTNLGRP_NEIGH, 0))
-               goto err;
-
-       odhcpd_register(&rtnl_event.ev);
-
-       // Open ICMPv6 socket
-       ping_socket = socket(AF_INET6, SOCK_RAW | SOCK_CLOEXEC, IPPROTO_ICMPV6);
-       if (ping_socket < 0) {
-               syslog(LOG_ERR, "Unable to open raw socket: %s", strerror(errno));
-                       return -1;
-       }
+       int ret = 0;
 
-       setsockopt(ping_socket, IPPROTO_RAW, IPV6_CHECKSUM, &val, sizeof(val));
-
-       // This is required by RFC 4861
-       val = 255;
-       setsockopt(ping_socket, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &val, sizeof(val));
-       setsockopt(ping_socket, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &val, sizeof(val));
-
-       // Filter all packages, we only want to send
-       struct icmp6_filter filt;
-       ICMP6_FILTER_SETBLOCKALL(&filt);
-       setsockopt(ping_socket, IPPROTO_ICMPV6, ICMP6_FILTER, &filt, sizeof(filt));
-
-       return 0;
-
-err:
-       if (rtnl_event.sock) {
-               nl_socket_free(rtnl_event.sock);
-               rtnl_event.sock = NULL;
-               rtnl_event.ev.uloop.fd = -1;
+       if (netlink_add_netevent_handler(&ndp_netevent_handler) < 0) {
+               syslog(LOG_ERR, "Failed to add ndp netevent handler");
+               ret = -1;
        }
 
-       return -1;
-}
-
-static void dump_neigh_table(const bool proxy)
-{
-       struct nl_msg *msg;
-       struct ndmsg ndm = {
-               .ndm_family = AF_INET6,
-               .ndm_flags = proxy ? NTF_PROXY : 0,
-       };
-
-       msg = nlmsg_alloc_simple(RTM_GETNEIGH, NLM_F_REQUEST | NLM_F_DUMP);
-       if (!msg)
-               return;
-
-       nlmsg_append(msg, &ndm, sizeof(ndm), 0);
-
-       nl_send_auto_complete(rtnl_event.sock, msg);
-
-       nlmsg_free(msg);
-}
-
-static void dump_addr6_table(void)
-{
-       struct nl_msg *msg;
-       struct ifaddrmsg ifa = {
-               .ifa_family = AF_INET6,
-       };
-
-       msg = nlmsg_alloc_simple(RTM_GETADDR, NLM_F_REQUEST | NLM_F_DUMP);
-       if (!msg)
-               return;
-
-       nlmsg_append(msg, &ifa, sizeof(ifa), 0);
-
-       nl_send_auto_complete(rtnl_event.sock, msg);
-
-       nlmsg_free(msg);
-}
-
-void ndp_handle_addr6_dump(void)
-{
-       if (!addr6_dump_rqs)
-               return;
-
-       dump_addr6_table();
-       addr6_dump_rqs = 0;
-}
-
-inline void ndp_rqs_addr6_dump(void)
-{
-       addr6_dump_rqs++;
+       return ret;
 }
 
-int setup_ndp_interface(struct interface *iface, bool enable)
+int ndp_setup_interface(struct interface *iface, bool enable)
 {
        int ret = 0, procfd;
        bool dump_neigh = false;
        char procbuf[64];
 
+       enable = enable && (iface->ndp == MODE_RELAY);
+
        snprintf(procbuf, sizeof(procbuf), "/proc/sys/net/ipv6/conf/%s/proxy_ndp", iface->ifname);
        procfd = open(procbuf, O_WRONLY);
 
@@ -196,113 +81,265 @@ int setup_ndp_interface(struct interface *iface, bool enable)
                goto out;
        }
 
-       if (iface->ndp_event.uloop.fd > 0) {
+       if (iface->ndp_ping_fd >= 0) {
+               close(iface->ndp_ping_fd);
+               iface->ndp_ping_fd = -1;
+       }
+
+       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;
 
-               if (!enable || iface->ndp != RELAYD_RELAY)
+               if (!enable)
                        if (write(procfd, "0\n", 2) < 0) {}
 
                dump_neigh = true;
        }
 
-       if (enable && iface->ndp == RELAYD_RELAY) {
+       if (enable) {
+               struct sockaddr_ll ll;
+               struct packet_mreq mreq;
+               struct icmp6_filter filt;
+               int val = 2;
+
                if (write(procfd, "1\n", 2) < 0) {}
 
-               int sock = socket(AF_PACKET, SOCK_DGRAM | SOCK_CLOEXEC, htons(ETH_P_IPV6));
-               if (sock < 0) {
-                       syslog(LOG_ERR, "Unable to open packet socket: %s",
-                                       strerror(errno));
+               /* Open ICMPv6 socket */
+               iface->ndp_ping_fd = socket(AF_INET6, SOCK_RAW | SOCK_CLOEXEC, IPPROTO_ICMPV6);
+               if (iface->ndp_ping_fd < 0) {
+                       syslog(LOG_ERR, "socket(AF_INET6): %m");
+                       ret = -1;
+                       goto out;
+               }
+
+               if (setsockopt(iface->ndp_ping_fd, SOL_SOCKET, SO_BINDTODEVICE,
+                              iface->ifname, strlen(iface->ifname)) < 0) {
+                       syslog(LOG_ERR, "setsockopt(SO_BINDTODEVICE): %m");
+                       ret = -1;
+                       goto out;
+               }
+
+               if (setsockopt(iface->ndp_ping_fd, IPPROTO_RAW, IPV6_CHECKSUM,
+                               &val, sizeof(val)) < 0) {
+                       syslog(LOG_ERR, "setsockopt(IPV6_CHECKSUM): %m");
+                       ret = -1;
+                       goto out;
+               }
+
+               /* This is required by RFC 4861 */
+               val = 255;
+               if (setsockopt(iface->ndp_ping_fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS,
+                              &val, sizeof(val)) < 0) {
+                       syslog(LOG_ERR, "setsockopt(IPV6_MULTICAST_HOPS): %m");
+                       ret = -1;
+                       goto out;
+               }
+
+               if (setsockopt(iface->ndp_ping_fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS,
+                              &val, sizeof(val)) < 0) {
+                       syslog(LOG_ERR, "setsockopt(IPV6_UNICAST_HOPS): %m");
+                       ret = -1;
+                       goto out;
+               }
+
+               /* Filter all packages, we only want to send */
+               ICMP6_FILTER_SETBLOCKALL(&filt);
+               if (setsockopt(iface->ndp_ping_fd, IPPROTO_ICMPV6, ICMP6_FILTER,
+                              &filt, sizeof(filt)) < 0) {
+                       syslog(LOG_ERR, "setsockopt(ICMP6_FILTER): %m");
+                       ret = -1;
+                       goto out;
+               }
+
+
+               iface->ndp_event.uloop.fd = socket(AF_PACKET, SOCK_DGRAM | SOCK_CLOEXEC, htons(ETH_P_IPV6));
+               if (iface->ndp_event.uloop.fd < 0) {
+                       syslog(LOG_ERR, "socket(AF_PACKET): %m");
                        ret = -1;
                        goto out;
                }
 
 #ifdef PACKET_RECV_TYPE
                int pktt = 1 << PACKET_MULTICAST;
-               setsockopt(sock, SOL_PACKET, PACKET_RECV_TYPE, &pktt, sizeof(pktt));
+               if (setsockopt(iface->ndp_event.uloop.fd, SOL_PACKET, PACKET_RECV_TYPE,
+                               &pktt, sizeof(pktt)) < 0) {
+                       syslog(LOG_ERR, "setsockopt(PACKET_RECV_TYPE): %m");
+                       ret = -1;
+                       goto out;
+               }
 #endif
 
-               if (setsockopt(sock, SOL_SOCKET, SO_ATTACH_FILTER,
+               if (setsockopt(iface->ndp_event.uloop.fd, SOL_SOCKET, SO_ATTACH_FILTER,
                                &bpf_prog, sizeof(bpf_prog))) {
-                       syslog(LOG_ERR, "Failed to set BPF: %s", strerror(errno));
+                       syslog(LOG_ERR, "setsockopt(SO_ATTACH_FILTER): %m");
+                       ret = -1;
+                       goto out;
+               }
+
+               memset(&ll, 0, sizeof(ll));
+               ll.sll_family = AF_PACKET;
+               ll.sll_ifindex = iface->ifindex;
+               ll.sll_protocol = htons(ETH_P_IPV6);
+
+               if (bind(iface->ndp_event.uloop.fd, (struct sockaddr*)&ll, sizeof(ll)) < 0) {
+                       syslog(LOG_ERR, "bind(): %m");
+                       ret = -1;
+                       goto out;
+               }
+
+               memset(&mreq, 0, sizeof(mreq));
+               mreq.mr_ifindex = iface->ifindex;
+               mreq.mr_type = PACKET_MR_ALLMULTI;
+               mreq.mr_alen = ETH_ALEN;
+
+               if (setsockopt(iface->ndp_event.uloop.fd, SOL_PACKET, PACKET_ADD_MEMBERSHIP,
+                               &mreq, sizeof(mreq)) < 0) {
+                       syslog(LOG_ERR, "setsockopt(PACKET_ADD_MEMBERSHIP): %m");
                        ret = -1;
                        goto out;
                }
 
-               struct sockaddr_ll ll = {
-                       .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));
-
-               struct packet_mreq mreq = {iface->ifindex, PACKET_MR_ALLMULTI, ETH_ALEN, {0}};
-               setsockopt(sock, SOL_PACKET, PACKET_ADD_MEMBERSHIP, &mreq, sizeof(mreq));
-
-               iface->ndp_event.uloop.fd = sock;
                iface->ndp_event.handle_dgram = handle_solicit;
                odhcpd_register(&iface->ndp_event);
 
-               // If we already were enabled dump is unnecessary, if not do dump
+               /* If we already were enabled dump is unnecessary, if not do dump */
                if (!dump_neigh)
-                       dump_neigh_table(false);
+                       netlink_dump_neigh_table(false);
                else
                        dump_neigh = false;
-
-               ndp_rqs_addr6_dump();
        }
 
        if (dump_neigh)
-               dump_neigh_table(true);
+               netlink_dump_neigh_table(true);
+
+ out:
+       if (ret < 0) {
+               if (iface->ndp_event.uloop.fd >= 0) {
+                       close(iface->ndp_event.uloop.fd);
+                       iface->ndp_event.uloop.fd = -1;
+               }
+
+               if (iface->ndp_ping_fd >= 0) {
+                       close(iface->ndp_ping_fd);
+                       iface->ndp_ping_fd = -1;
+               }
+       }
 
-out:
        if (procfd >= 0)
                close(procfd);
 
        return ret;
 }
 
+static void ndp_netevent_cb(unsigned long event, struct netevent_handler_info *info)
+{
+       struct interface *iface = info->iface;
+       bool add = true;
+
+       if (!iface || iface->ndp == MODE_DISABLED)
+               return;
 
-// Send an ICMP-ECHO. This is less for actually pinging but for the
-// neighbor cache to be kept up-to-date.
+       switch (event) {
+       case NETEV_ADDR6_DEL:
+               add = false;
+               netlink_dump_neigh_table(false);
+               /* fall through */
+       case NETEV_ADDR6_ADD:
+               setup_addr_for_relaying(&info->addr.in6, iface, add);
+               break;
+       case NETEV_NEIGH6_DEL:
+               add = false;
+               /* fall through */
+       case NETEV_NEIGH6_ADD:
+               if (info->neigh.flags & NTF_PROXY) {
+                       if (add) {
+                               netlink_setup_proxy_neigh(&info->neigh.dst.in6, iface->ifindex, false);
+                               setup_route(&info->neigh.dst.in6, iface, false);
+                               netlink_dump_neigh_table(false);
+                       }
+                       break;
+               }
+
+               if (add &&
+                   !(info->neigh.state &
+                     (NUD_REACHABLE|NUD_STALE|NUD_DELAY|NUD_PROBE|NUD_PERMANENT|NUD_NOARP)))
+                       break;
+
+               setup_addr_for_relaying(&info->neigh.dst.in6, iface, add);
+               setup_route(&info->neigh.dst.in6, iface, add);
+
+               if (!add)
+                       netlink_dump_neigh_table(false);
+               break;
+       default:
+               break;
+       }
+}
+
+/* Send an ICMP-ECHO. This is less for actually pinging but for the
+ * neighbor cache to be kept up-to-date. */
 static void ping6(struct in6_addr *addr,
                const struct interface *iface)
 {
-       struct sockaddr_in6 dest = { .sin6_family = AF_INET6, .sin6_addr = *addr, .sin6_scope_id = iface->ifindex, };
+       struct sockaddr_in6 dest = { .sin6_family = AF_INET6, .sin6_addr = *addr , };
        struct icmp6_hdr echo = { .icmp6_type = ICMP6_ECHO_REQUEST };
        struct iovec iov = { .iov_base = &echo, .iov_len = sizeof(echo) };
        char ipbuf[INET6_ADDRSTRLEN];
 
        inet_ntop(AF_INET6, addr, ipbuf, sizeof(ipbuf));
-       syslog(LOG_NOTICE, "Pinging for %s%%%s", ipbuf, iface->ifname);
+       syslog(LOG_DEBUG, "Pinging for %s on %s", ipbuf, iface->name);
 
-       odhcpd_setup_route(addr, 128, iface, NULL, 128, true);
-       odhcpd_send(ping_socket, &dest, &iov, 1, iface);
-       odhcpd_setup_route(addr, 128, iface, NULL, 128, false);
+       netlink_setup_route(addr, 128, iface->ifindex, NULL, 128, true);
+       odhcpd_send(iface->ndp_ping_fd, &dest, &iov, 1, iface);
+       netlink_setup_route(addr, 128, iface->ifindex, NULL, 128, false);
 }
 
-// Handle solicitations
+/* Send a Neighbor Advertisement. */
+static void send_na(struct in6_addr *to_addr,
+               const struct interface *iface, struct in6_addr *for_addr,
+               const uint8_t *mac)
+{
+       struct sockaddr_in6 dest = { .sin6_family = AF_INET6, .sin6_addr = *to_addr };
+       char pbuf[sizeof(struct nd_neighbor_advert) + sizeof(struct nd_opt_hdr) + 6];
+       struct nd_neighbor_advert *adv = (struct nd_neighbor_advert*)pbuf;
+       struct nd_opt_hdr *opt = (struct nd_opt_hdr*) &pbuf[sizeof(struct nd_neighbor_advert)];
+       struct iovec iov = { .iov_base = &pbuf, .iov_len = sizeof(pbuf) };
+       char ipbuf[INET6_ADDRSTRLEN];
+
+       memset(pbuf, 0, sizeof(pbuf));
+       adv->nd_na_hdr = (struct icmp6_hdr) {
+               .icmp6_type = ND_NEIGHBOR_ADVERT,
+               .icmp6_dataun.icmp6_un_data32 = { ND_NA_FLAG_SOLICITED }
+       };
+       adv->nd_na_target = *for_addr;
+       *opt = (struct nd_opt_hdr) { .nd_opt_type = ND_OPT_TARGET_LINKADDR, .nd_opt_len = 1 };
+       memcpy(&pbuf[sizeof(struct nd_neighbor_advert) + sizeof(struct nd_opt_hdr)], mac, 6);
+
+       inet_ntop(AF_INET6, to_addr, ipbuf, sizeof(ipbuf));
+       syslog(LOG_DEBUG, "Answering NS to %s on %s", ipbuf, iface->ifname);
+
+       odhcpd_send(iface->ndp_ping_fd, &dest, &iov, 1, iface);
+}
+
+/* Handle solicitations */
 static void handle_solicit(void *addr, void *data, size_t len,
                struct interface *iface, _unused void *dest)
 {
        struct ip6_hdr *ip6 = data;
        struct nd_neighbor_solicit *req = (struct nd_neighbor_solicit*)&ip6[1];
        struct sockaddr_ll *ll = addr;
+       struct interface *c;
        char ipbuf[INET6_ADDRSTRLEN];
        uint8_t mac[6];
 
-       // Solicitation is for duplicate address detection
+       /* Solicitation is for duplicate address detection */
        bool ns_is_dad = IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src);
 
-       // Don't process solicit messages on non relay interfaces
-       // Don't forward any non-DAD solicitation for external ifaces
-       // TODO: check if we should even forward DADs for them
-       if (iface->ndp != RELAYD_RELAY || (iface->external && !ns_is_dad))
+       /* Don't process solicit messages on non relay interfaces
+        * Don't forward any non-DAD solicitation for external ifaces
+        * TODO: check if we should even forward DADs for them */
+       if (iface->ndp != MODE_RELAY || (iface->external && !ns_is_dad))
                return;
 
        if (len < sizeof(*ip6) + sizeof(*req))
@@ -311,85 +348,46 @@ static void handle_solicit(void *addr, void *data, size_t len,
        if (IN6_IS_ADDR_LINKLOCAL(&req->nd_ns_target) ||
                        IN6_IS_ADDR_LOOPBACK(&req->nd_ns_target) ||
                        IN6_IS_ADDR_MULTICAST(&req->nd_ns_target))
-               return; // Invalid target
+               return; /* Invalid target */
 
        inet_ntop(AF_INET6, &req->nd_ns_target, ipbuf, sizeof(ipbuf));
-       syslog(LOG_DEBUG, "Got a NS for %s%%%s", ipbuf, iface->ifname);
+       syslog(LOG_DEBUG, "Got a NS for %s on %s", ipbuf, iface->name);
 
        odhcpd_get_mac(iface, mac);
        if (!memcmp(ll->sll_addr, mac, sizeof(mac)))
-               return; // Looped back
+               return; /* Looped back */
 
-       struct interface *c;
-       list_for_each_entry(c, &interfaces, head)
-               if (iface != c && c->ndp == RELAYD_RELAY &&
+       avl_for_each_element(&interfaces, c, avl) {
+               if (iface != c && c->ndp == MODE_RELAY &&
                                (ns_is_dad || !c->external))
                        ping6(&req->nd_ns_target, c);
+       }
+
+       /* Catch global-addressed NS and answer them manually.
+        * The kernel won't answer these and cannot route them either. */
+       if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) &&
+                       IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) {
+               bool is_proxy_neigh = netlink_get_interface_proxy_neigh(iface->ifindex,
+                               &req->nd_ns_target) == 1;
+
+               if (is_proxy_neigh)
+                       send_na(&ip6->ip6_src, iface, &req->nd_ns_target, mac);
+       }
 }
 
-// Use rtnetlink to modify kernel routes
+/* Use rtnetlink to modify kernel routes */
 static void setup_route(struct in6_addr *addr, struct interface *iface, bool add)
 {
        char ipbuf[INET6_ADDRSTRLEN];
 
        inet_ntop(AF_INET6, addr, ipbuf, sizeof(ipbuf));
-       syslog(LOG_NOTICE, "%s about %s%%%s",
-                       (add) ? "Learned" : "Forgot", ipbuf, iface->ifname);
+       syslog(LOG_DEBUG, "%s about %s%s on %s",
+                       (add) ? "Learning" : "Forgetting",
+                       iface->learn_routes ? "proxy routing for " : "",
+                       ipbuf, iface->name);
 
        if (iface->learn_routes)
-               odhcpd_setup_route(addr, 128, iface, NULL, 1024, add);
-}
-
-// compare prefixes
-static int prefixcmp(const void *va, const void *vb)
-{
-       const struct odhcpd_ipaddr *a = va, *b = vb;
-       uint32_t a_pref = IN6_IS_ADDR_ULA(&a->addr) ? 1 : a->preferred;
-       uint32_t b_pref = IN6_IS_ADDR_ULA(&b->addr) ? 1 : b->preferred;
-       return (a_pref < b_pref) ? 1 : (a_pref > b_pref) ? -1 : 0;
-}
-
-// Check address update
-static void check_addr_updates(struct interface *iface)
-{
-       struct odhcpd_ipaddr addr[RELAYD_MAX_ADDRS] = {{IN6ADDR_ANY_INIT, 0, 0, 0, 0}};
-       time_t now = odhcpd_time();
-       ssize_t len = odhcpd_get_interface_addresses(iface->ifindex, addr, ARRAY_SIZE(addr));
-
-       if (len < 0)
-               return;
-
-       qsort(addr, len, sizeof(*addr), prefixcmp);
-
-       for (int i = 0; i < len; ++i) {
-               if (addr[i].preferred < UINT32_MAX - now)
-                       addr[i].preferred += now;
-
-               if (addr[i].valid < UINT32_MAX - now)
-                       addr[i].valid += now;
-       }
-
-       bool change = len != (ssize_t)iface->ia_addr_len;
-       for (ssize_t i = 0; !change && i < len; ++i)
-               if (!IN6_ARE_ADDR_EQUAL(&addr[i].addr, &iface->ia_addr[i].addr) ||
-                               (addr[i].preferred > 0) != (iface->ia_addr[i].preferred > 0) ||
-                               addr[i].valid < iface->ia_addr[i].valid ||
-                               addr[i].preferred < iface->ia_addr[i].preferred)
-                       change = true;
-
-       if (change)
-               dhcpv6_ia_preupdate(iface);
-
-       memcpy(iface->ia_addr, addr, len * sizeof(*addr));
-       iface->ia_addr_len = len;
-
-       if (change)
-               dhcpv6_ia_postupdate(iface, now);
-
-       if (change) {
-               syslog(LOG_INFO, "Raising SIGUSR1 due to address change on %s", iface->ifname);
-               raise(SIGUSR1);
-       }
+               netlink_setup_route(addr, 128, iface->ifindex, NULL, 1024, add);
 }
 
 static void setup_addr_for_relaying(struct in6_addr *addr, struct interface *iface, bool add)
@@ -399,169 +397,16 @@ static void setup_addr_for_relaying(struct in6_addr *addr, struct interface *ifa
 
        inet_ntop(AF_INET6, addr, ipbuf, sizeof(ipbuf));
 
-       list_for_each_entry(c, &interfaces, head) {
-               if (iface == c || (c->ndp != RELAYD_RELAY && !add))
+       avl_for_each_element(&interfaces, c, avl) {
+               if (iface == c || c->ndp != MODE_RELAY)
                        continue;
 
-               bool neigh_add = (c->ndp == RELAYD_RELAY ? add : false);
-
-               if (odhcpd_setup_proxy_neigh(addr, c, neigh_add))
-                       syslog(LOG_DEBUG, "Failed to %s proxy neighbour entry %s%%%s",
-                               neigh_add ? "add" : "delete", ipbuf, c->ifname);
-               else
-                       syslog(LOG_DEBUG, "%s proxy neighbour entry %s%%%s",
-                               neigh_add ? "Added" : "Deleted", ipbuf, c->ifname);
+               if (netlink_setup_proxy_neigh(addr, c->ifindex, add)) {
+                       if (add)
+                               syslog(LOG_ERR, "Failed to add proxy neighbour entry %s on %s",
+                                      ipbuf, c->name);
+               } else
+                       syslog(LOG_DEBUG, "%s proxy neighbour entry %s on %s",
+                              add ? "Added" : "Deleted", ipbuf, c->name);
        }
 }
-
-static void handle_rtnl_event(struct odhcpd_event *e)
-{
-       struct event_socket *ev_sock = container_of(e, struct event_socket, ev);
-
-       nl_recvmsgs_default(ev_sock->sock);
-}
-
-
-// Handler for neighbor cache entries from the kernel. This is our source
-// to learn and unlearn hosts on interfaces.
-static int cb_rtnl_valid(struct nl_msg *msg, _unused void *arg)
-{
-       struct nlmsghdr *hdr = nlmsg_hdr(msg);
-       struct in6_addr *addr = NULL;
-       struct interface *iface = NULL;
-       bool add = false;
-       char ipbuf[INET6_ADDRSTRLEN];
-
-       switch (hdr->nlmsg_type) {
-       case RTM_NEWROUTE:
-       case RTM_DELROUTE: {
-               struct rtmsg *rtm = nlmsg_data(hdr);
-
-               if (!nlmsg_valid_hdr(hdr, sizeof(*rtm)) ||
-                               rtm->rtm_family != AF_INET6)
-                       return NL_SKIP;
-
-               if (rtm->rtm_dst_len == 0) {
-                       syslog(LOG_INFO, "Raising SIGUSR1 due to default route change");
-                       raise(SIGUSR1);
-               }
-               return NL_OK;
-       }
-
-       case RTM_NEWADDR:
-               add = true;
-       case RTM_DELADDR: {
-               struct ifaddrmsg *ifa = nlmsg_data(hdr);
-               struct nlattr *nla[__IFA_MAX];
-
-               if (!nlmsg_valid_hdr(hdr, sizeof(*ifa)) ||
-                               ifa->ifa_family != AF_INET6)
-                       return NL_SKIP;
-
-               iface = odhcpd_get_interface_by_index(ifa->ifa_index);
-               if (!iface)
-                       return NL_SKIP;
-
-               nlmsg_parse(hdr, sizeof(*ifa), nla, __IFA_MAX - 1, NULL);
-               if (!nla[IFA_ADDRESS])
-                       return NL_SKIP;
-
-               addr = nla_data(nla[IFA_ADDRESS]);
-               if (!addr || IN6_IS_ADDR_LINKLOCAL(addr) ||
-                               IN6_IS_ADDR_MULTICAST(addr))
-                       return NL_SKIP;
-
-               inet_ntop(AF_INET6, addr, ipbuf, sizeof(ipbuf));
-               syslog(LOG_DEBUG, "Netlink %s %s%%%s", true ? "newaddr" : "deladdr",
-                       ipbuf, iface->ifname);
-
-               check_addr_updates(iface);
-
-               if (iface->ndp != RELAYD_RELAY)
-                       break;
-
-               /* handle the relay logic below */
-               setup_addr_for_relaying(addr, iface, add);
-
-               if (!add)
-                       dump_neigh_table(false);
-               break;
-       }
-
-       case RTM_NEWNEIGH:
-               add = true;
-       case RTM_DELNEIGH: {
-               struct ndmsg *ndm = nlmsg_data(hdr);
-               struct nlattr *nla[__NDA_MAX];
-
-               if (!nlmsg_valid_hdr(hdr, sizeof(*ndm)) ||
-                               ndm->ndm_family != AF_INET6)
-                       return NL_SKIP;
-
-               iface = odhcpd_get_interface_by_index(ndm->ndm_ifindex);
-               if (!iface || iface->ndp != RELAYD_RELAY)
-                       return (iface ? NL_OK : NL_SKIP);
-
-               nlmsg_parse(hdr, sizeof(*ndm), nla, __NDA_MAX - 1, NULL);
-               if (!nla[NDA_DST])
-                       return NL_SKIP;
-
-               addr = nla_data(nla[NDA_DST]);
-               if (!addr || IN6_IS_ADDR_LINKLOCAL(addr) ||
-                               IN6_IS_ADDR_MULTICAST(addr))
-                       return NL_SKIP;
-
-               inet_ntop(AF_INET6, addr, ipbuf, sizeof(ipbuf));
-               syslog(LOG_DEBUG, "Netlink %s %s%%%s", true ? "newneigh" : "delneigh",
-                       ipbuf, iface->ifname);
-
-               if (ndm->ndm_flags & NTF_PROXY) {
-                       /* Dump and flush proxy entries */
-                       if (hdr->nlmsg_type == RTM_NEWNEIGH) {
-                               odhcpd_setup_proxy_neigh(addr, iface, false);
-                               setup_route(addr, iface, false);
-                               dump_neigh_table(false);
-                       }
-
-                       return NL_OK;
-               }
-
-               if (add && !(ndm->ndm_state &
-                               (NUD_REACHABLE | NUD_STALE | NUD_DELAY | NUD_PROBE |
-                                NUD_PERMANENT | NUD_NOARP)))
-                       return NL_OK;
-
-               setup_addr_for_relaying(addr, iface, add);
-               setup_route(addr, iface, add);
-
-               if (!add)
-                       dump_neigh_table(false);
-               break;
-       }
-
-       default:
-               return NL_SKIP;
-       }
-
-       return NL_OK;
-}
-
-static void catch_rtnl_err(struct odhcpd_event *e, int error)
-{
-       struct event_socket *ev_sock = container_of(e, struct event_socket, ev);
-
-       if (error != ENOBUFS)
-               goto err;
-
-       /* Double netlink event buffer size */
-       ev_sock->sock_bufsize *= 2;
-
-       if (nl_socket_set_buffer_size(ev_sock->sock, ev_sock->sock_bufsize, 0))
-               goto err;
-
-       dump_addr6_table();
-       return;
-
-err:
-       odhcpd_deregister(e);
-}