X-Git-Url: http://git.archive.openwrt.org/?p=project%2Fodhcpd.git;a=blobdiff_plain;f=src%2Fndp.c;h=93b70fc2e0af91ac6b98d7b62f45d6a437953860;hp=17ec8b48efa3657c57dba3de677b200446923906;hb=24d21c7c26d07e93fb329ac62da5e974cf44213b;hpb=a85ccf1aa14d3d860e6ac0e7c56ba4695462afa1

diff --git a/src/ndp.c b/src/ndp.c
index 17ec8b4..93b70fc 100644
--- a/src/ndp.c
+++ b/src/ndp.c
@@ -17,6 +17,8 @@
 #include <signal.h>
 #include <errno.h>
 
+#include <fcntl.h>
+#include <unistd.h>
 #include <arpa/inet.h>
 #include <sys/socket.h>
 #include <net/ethernet.h>
@@ -26,29 +28,38 @@
 
 #include <linux/rtnetlink.h>
 #include <linux/filter.h>
+
+#include <netlink/msg.h>
+#include <netlink/socket.h>
+#include <netlink/attr.h>
+
 #include "router.h"
+#include "dhcpv6.h"
 #include "ndp.h"
 
-
+struct event_socket {
+	struct odhcpd_event ev;
+	struct nl_sock *sock;
+	int sock_bufsize;
+};
 
 static void handle_solicit(void *addr, void *data, size_t len,
-		struct interface *iface);
-static void handle_rtnetlink(void *addr, void *data, size_t len,
-		struct interface *iface);
-static struct ndp_neighbor* find_neighbor(struct in6_addr *addr, bool strict);
-static void modify_neighbor(struct in6_addr *addr, struct interface *iface,
-		bool add);
-static ssize_t ping6(struct in6_addr *addr,
-		const struct interface *iface);
-
-static struct list_head neighbors = LIST_HEAD_INIT(neighbors);
-static size_t neighbor_count = 0;
-static uint32_t rtnl_seqid = 0;
+		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 ping_socket = -1;
-static struct odhcpd_event ndp_event = {{.fd = -1}, handle_solicit};
-static struct odhcpd_event rtnl_event = {{.fd = -1}, handle_rtnetlink};
-
+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
 static struct sock_filter bpf[] = {
@@ -66,48 +77,28 @@ static const struct sock_fprog bpf_prog = {sizeof(bpf) / sizeof(*bpf), bpf};
 // Initialize NDP-proxy
 int init_ndp(void)
 {
-	// Setup netlink socket
-	if ((rtnl_event.uloop.fd = odhcpd_open_rtnl()) < 0)
-		return -1;
-
-	// Receive netlink neighbor and ip-address events
-	uint32_t group = RTNLGRP_IPV6_IFADDR;
-	setsockopt(rtnl_event.uloop.fd, SOL_NETLINK,
-			NETLINK_ADD_MEMBERSHIP, &group, sizeof(group));
-	group = RTNLGRP_IPV6_ROUTE;
-	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);
+	int val = 2;
 
+	rtnl_event.sock = odhcpd_create_nl_socket(NETLINK_ROUTE);
+	if (!rtnl_event.sock)
+		goto err;
 
-	// Create socket for intercepting NDP
-	int sock = socket(AF_PACKET, SOCK_DGRAM | SOCK_CLOEXEC | SOCK_NONBLOCK,
-			htons(ETH_P_ALL)); // ETH_P_ALL for ingress + egress
-	if (sock < 0) {
-		syslog(LOG_ERR, "Unable to open packet socket: %s",
-				strerror(errno));
-		return -1;
-	}
+	rtnl_event.ev.uloop.fd = nl_socket_get_fd(rtnl_event.sock);
 
-	if (setsockopt(sock, SOL_SOCKET, SO_ATTACH_FILTER,
-			&bpf_prog, sizeof(bpf_prog))) {
-		syslog(LOG_ERR, "Failed to set BPF: %s", strerror(errno));
-		return -1;
-	}
+	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;
 
-	ndp_event.uloop.fd = sock;
-	odhcpd_register(&ndp_event);
+	odhcpd_register(&rtnl_event.ev);
 
 	// Open ICMPv6 socket
 	ping_socket = socket(AF_INET6, SOCK_RAW | SOCK_CLOEXEC, IPPROTO_ICMPV6);
@@ -116,7 +107,6 @@ int init_ndp(void)
 			return -1;
 	}
 
-	int val = 2;
 	setsockopt(ping_socket, IPPROTO_RAW, IPV6_CHECKSUM, &val, sizeof(val));
 
 	// This is required by RFC 4861
@@ -129,112 +119,178 @@ int init_ndp(void)
 	ICMP6_FILTER_SETBLOCKALL(&filt);
 	setsockopt(ping_socket, IPPROTO_ICMPV6, ICMP6_FILTER, &filt, sizeof(filt));
 
+	return 0;
 
-	// Netlink socket, continued...
-	group = RTNLGRP_NEIGH;
-	setsockopt(rtnl_event.uloop.fd, SOL_NETLINK, NETLINK_ADD_MEMBERSHIP, &group, sizeof(group));
+err:
+	if (rtnl_event.sock) {
+		nl_socket_free(rtnl_event.sock);
+		rtnl_event.sock = NULL;
+		rtnl_event.ev.uloop.fd = -1;
+	}
 
-	// Synthesize initial neighbor events
-	struct {
-		struct nlmsghdr nh;
-		struct ndmsg ndm;
-	} req = {
-		{sizeof(req), RTM_GETNEIGH, NLM_F_REQUEST | NLM_F_DUMP,
-				++rtnl_seqid, 0},
-		{.ndm_family = AF_INET6}
+	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,
 	};
-	send(rtnl_event.uloop.fd, &req, sizeof(req), MSG_DONTWAIT);
 
-	return 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_addr_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);
+}
 
 int setup_ndp_interface(struct interface *iface, bool enable)
 {
-	struct packet_mreq mreq = {iface->ifindex, PACKET_MR_ALLMULTI, ETH_ALEN, {0}};
-	setsockopt(ndp_event.uloop.fd, SOL_PACKET, PACKET_DROP_MEMBERSHIP, &mreq, sizeof(mreq));
+	int ret = 0, procfd;
+	bool dump_neigh = false;
+	char procbuf[64];
 
-	struct ndp_neighbor *c, *n;
-	list_for_each_entry_safe(c, n, &neighbors, head)
-		if (c->iface == iface && (c->timeout == 0 || iface->ndp != RELAYD_RELAY || !enable))
-			modify_neighbor(&c->addr, c->iface, false);
+	snprintf(procbuf, sizeof(procbuf), "/proc/sys/net/ipv6/conf/%s/proxy_ndp", iface->ifname);
+	procfd = open(procbuf, O_WRONLY);
+
+	if (procfd < 0) {
+		ret = -1;
+		goto out;
+	}
+
+	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 (write(procfd, "0\n", 2) < 0) {}
+
+		dump_neigh = true;
+	}
+
+	if (enable && (iface->ra == RELAYD_SERVER ||
+			iface->dhcpv6 == RELAYD_SERVER || iface->ndp == RELAYD_RELAY))
+		dump_addr_table();
 
 	if (enable && iface->ndp == RELAYD_RELAY) {
-		setsockopt(ndp_event.uloop.fd, SOL_PACKET, PACKET_ADD_MEMBERSHIP, &mreq, sizeof(mreq));
+		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));
+			ret = -1;
+			goto out;
+		}
 
-		if (iface->static_ndp_len) {
-			char *entry = alloca(iface->static_ndp_len), *saveptr;
-			if (!entry) {
-				syslog(LOG_ERR, "Alloca failed for static NDP list");
-				return -1;
-			}
-			memcpy(entry, iface->static_ndp, iface->static_ndp_len);
-
-			for (entry = strtok_r(entry, " ", &saveptr); entry; entry = strtok_r(NULL, " ", &saveptr)) {
-				char *sep;
-				struct ndp_neighbor *n = malloc(sizeof(*n));
-				if (!n) {
-					syslog(LOG_ERR, "Malloc failed for static NDP-prefix %s", entry);
-					return -1;
-				}
-
-				n->iface = iface;
-				n->timeout = 0;
-
-				sep = strchr(entry, '/');
-				if (!sep) {
-					free(n);
-					syslog(LOG_ERR, "Invalid static NDP-prefix %s", entry);
-					return -1;
-				}
-				
-				*sep = 0;
-				n->len = atoi(sep + 1);
-				if (inet_pton(AF_INET6, entry, &n->addr) != 1 || n->len > 128) {
-					free(n);
-					syslog(LOG_ERR, "Invalid static NDP-prefix %s/%s", entry, sep + 1);
-					return -1;
-				}
-
-				list_add(&n->head, &neighbors);
-			}
+#ifdef PACKET_RECV_TYPE
+		int pktt = 1 << PACKET_MULTICAST;
+		setsockopt(sock, SOL_PACKET, PACKET_RECV_TYPE, &pktt, sizeof(pktt));
+#endif
+
+		if (setsockopt(sock, SOL_SOCKET, SO_ATTACH_FILTER,
+				&bpf_prog, sizeof(bpf_prog))) {
+			syslog(LOG_ERR, "Failed to set BPF: %s", strerror(errno));
+			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 (!dump_neigh)
+			dump_neigh_table(false);
+		else
+			dump_neigh = false;
 	}
 
-	return 0;
+	if (dump_neigh)
+		dump_neigh_table(true);
+
+out:
+	if (procfd >= 0)
+		close(procfd);
+
+	return ret;
 }
 
 
 // Send an ICMP-ECHO. This is less for actually pinging but for the
 // neighbor cache to be kept up-to-date.
-static ssize_t ping6(struct in6_addr *addr,
+static void ping6(struct in6_addr *addr,
 		const struct interface *iface)
 {
-	struct sockaddr_in6 dest = {AF_INET6, 0, 0, *addr, 0};
-	struct icmp6_hdr echo = {.icmp6_type = ICMP6_ECHO_REQUEST};
-	struct iovec iov = {&echo, sizeof(echo)};
-
-	// Linux seems to not honor IPV6_PKTINFO on raw-sockets, so work around
-	setsockopt(ping_socket, SOL_SOCKET, SO_BINDTODEVICE,
-			iface->ifname, sizeof(iface->ifname));
-	return odhcpd_send(ping_socket, &dest, &iov, 1, iface);
-}
+	struct sockaddr_in6 dest = { .sin6_family = AF_INET6, .sin6_addr = *addr, .sin6_scope_id = iface->ifindex, };
+	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);
 
+	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);
+}
 
 // Handle solicitations
 static void handle_solicit(void *addr, void *data, size_t len,
-		struct interface *iface)
+		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;
+	char ipbuf[INET6_ADDRSTRLEN];
+	uint8_t mac[6];
 
 	// 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->external && !ns_is_dad)
+	if (iface->ndp != RELAYD_RELAY || (iface->external && !ns_is_dad))
 		return;
 
 	if (len < sizeof(*ip6) + sizeof(*req))
@@ -245,281 +301,278 @@ static void handle_solicit(void *addr, void *data, size_t len,
 			IN6_IS_ADDR_MULTICAST(&req->nd_ns_target))
 		return; // Invalid target
 
-	char ipbuf[INET6_ADDRSTRLEN];
 	inet_ntop(AF_INET6, &req->nd_ns_target, ipbuf, sizeof(ipbuf));
-	syslog(LOG_DEBUG, "Got a NS for %s", ipbuf);
+	syslog(LOG_DEBUG, "Got a NS for %s%%%s", ipbuf, iface->ifname);
 
-	uint8_t mac[6];
 	odhcpd_get_mac(iface, mac);
-	if (!memcmp(ll->sll_addr, mac, sizeof(mac)) &&
-			ll->sll_pkttype != PACKET_OUTGOING)
+	if (!memcmp(ll->sll_addr, mac, sizeof(mac)))
 		return; // Looped back
 
-	time_t now = time(NULL);
-
-	struct ndp_neighbor *n = find_neighbor(&req->nd_ns_target, false);
-	if (n && (n->iface || abs(n->timeout - now) < 5)) {
-		syslog(LOG_DEBUG, "%s is on %s", ipbuf,
-				(n->iface) ? n->iface->ifname : "<pending>");
-		if (!n->iface || n->iface == iface)
-			return;
-
-		// Found on other interface, answer with advertisement
-		struct {
-			struct nd_neighbor_advert body;
-			struct nd_opt_hdr opt_ll_hdr;
-			uint8_t mac[6];
-		} advert = {
-			.body = {
-				.nd_na_hdr = {ND_NEIGHBOR_ADVERT,
-					0, 0, {{0}}},
-				.nd_na_target = req->nd_ns_target,
-			},
-			.opt_ll_hdr = {ND_OPT_TARGET_LINKADDR, 1},
-		};
-
-		memcpy(advert.mac, mac, sizeof(advert.mac));
-		advert.body.nd_na_flags_reserved = ND_NA_FLAG_ROUTER |
-				ND_NA_FLAG_SOLICITED;
-
-		struct sockaddr_in6 dest = {AF_INET6, 0, 0, ALL_IPV6_NODES, 0};
-		if (!ns_is_dad) // If not DAD, then unicast to source
-			dest.sin6_addr = ip6->ip6_src;
-
-		// Linux seems to not honor IPV6_PKTINFO on raw-sockets, so work around
-		setsockopt(ping_socket, SOL_SOCKET, SO_BINDTODEVICE,
-					iface->ifname, sizeof(iface->ifname));
-		struct iovec iov = {&advert, sizeof(advert)};
-		odhcpd_send(ping_socket, &dest, &iov, 1, iface);
-	} else {
-		// Send echo to all other interfaces to see where target is on
-		// This will trigger neighbor discovery which is what we want.
-		// We will observe the neighbor cache to see results.
-
-		ssize_t sent = 0;
-		struct interface *c;
-		list_for_each_entry(c, &interfaces, head)
-			if (iface->ndp == RELAYD_RELAY && iface != c &&
-					(!ns_is_dad || !c->external == false))
-				sent += ping6(&req->nd_ns_target, c);
-
-		if (sent > 0) // Sent a ping, add pending neighbor entry
-			modify_neighbor(&req->nd_ns_target, NULL, true);
-	}
+	struct interface *c;
+	list_for_each_entry(c, &interfaces, head)
+		if (iface != c && c->ndp == RELAYD_RELAY &&
+				(ns_is_dad || !c->external))
+			ping6(&req->nd_ns_target, c);
 }
 
-
-void odhcpd_setup_route(const struct in6_addr *addr, int prefixlen,
-		const struct interface *iface, const struct in6_addr *gw, bool add)
+// Use rtnetlink to modify kernel routes
+static void setup_route(struct in6_addr *addr, struct interface *iface, bool add)
 {
-	struct req {
-		struct nlmsghdr nh;
-		struct rtmsg rtm;
-		struct rtattr rta_dst;
-		struct in6_addr dst_addr;
-		struct rtattr rta_oif;
-		uint32_t ifindex;
-		struct rtattr rta_table;
-		uint32_t table;
-		struct rtattr rta_gw;
-		struct in6_addr gw;
-	} req = {
-		{sizeof(req), 0, NLM_F_REQUEST, ++rtnl_seqid, 0},
-		{AF_INET6, prefixlen, 0, 0, 0, 0, 0, 0, 0},
-		{sizeof(struct rtattr) + sizeof(struct in6_addr), RTA_DST},
-		*addr,
-		{sizeof(struct rtattr) + sizeof(uint32_t), RTA_OIF},
-		iface->ifindex,
-		{sizeof(struct rtattr) + sizeof(uint32_t), RTA_TABLE},
-		RT_TABLE_MAIN,
-		{sizeof(struct rtattr) + sizeof(struct in6_addr), RTA_GATEWAY},
-		IN6ADDR_ANY_INIT,
-	};
+	char ipbuf[INET6_ADDRSTRLEN];
 
-	if (gw)
-		req.gw = *gw;
-
-	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_scope = (gw) ? RT_SCOPE_UNIVERSE : RT_SCOPE_LINK;
-		req.rtm.rtm_type = RTN_UNICAST;
-	} else {
-		req.nh.nlmsg_type = RTM_DELROUTE;
-		req.rtm.rtm_scope = RT_SCOPE_NOWHERE;
-	}
+	inet_ntop(AF_INET6, addr, ipbuf, sizeof(ipbuf));
+	syslog(LOG_NOTICE, "%s about %s%%%s",
+			(add) ? "Learned" : "Forgot", ipbuf, iface->ifname);
 
-	size_t reqlen = (gw) ? sizeof(req) : offsetof(struct req, rta_gw);
-	send(rtnl_event.uloop.fd, &req, reqlen, MSG_DONTWAIT);
+	if (iface->learn_routes)
+		odhcpd_setup_route(addr, 128, iface, NULL, 1024, add);
 }
 
-// Use rtnetlink to modify kernel routes
-static void setup_route(struct in6_addr *addr, struct interface *iface,
-		bool add)
+// compare prefixes
+static int prefixcmp(const void *va, const void *vb)
 {
-	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>");
+	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 (!iface || !iface->learn_routes)
+	if (len < 0)
 		return;
 
-	odhcpd_setup_route(addr, 128, iface, NULL, add);
+	qsort(addr, len, sizeof(*addr), prefixcmp);
+
+	for (int i = 0; i < len; ++i) {
+		addr[i].addr.s6_addr32[3] = 0;
+
+		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);
+	}
 }
 
-static void free_neighbor(struct ndp_neighbor *n)
+void setup_addr_for_relaying(struct in6_addr *addr, struct interface *iface, bool add)
 {
-	setup_route(&n->addr, n->iface, false);
-	list_del(&n->head);
-	free(n);
-	--neighbor_count;
+	struct interface *c;
+	char ipbuf[INET6_ADDRSTRLEN];
+
+	inet_ntop(AF_INET6, addr, ipbuf, sizeof(ipbuf));
+
+	list_for_each_entry(c, &interfaces, head) {
+		if (iface == c || (c->ndp != RELAYD_RELAY && !add))
+			continue;
+
+		add = (c->ndp == RELAYD_RELAY ? add : false);
+
+		if (odhcpd_setup_proxy_neigh(addr, c, add))
+			syslog(LOG_DEBUG, "Failed to %s proxy neighbour entry %s%%%s",
+				add ? "add" : "delete", ipbuf, iface->ifname);
+		else
+			syslog(LOG_DEBUG, "%s proxy neighbour entry %s%%%s",
+				add ? "Added" : "Deleted", ipbuf, iface->ifname);
+	}
 }
 
-static struct ndp_neighbor* find_neighbor(struct in6_addr *addr, bool strict)
+void setup_ping6(struct in6_addr *addr, struct interface *iface)
 {
-	time_t now = time(NULL);
-	struct ndp_neighbor *n, *e;
-	list_for_each_entry_safe(n, e, &neighbors, head) {
-		if ((!strict && !odhcpd_bmemcmp(&n->addr, addr, n->len)) ||
-				(n->len == 128 && IN6_ARE_ADDR_EQUAL(&n->addr, addr)))
-			return n;
-
-		if (!n->iface && abs(n->timeout - now) >= 5)
-			free_neighbor(n);
+	struct interface *c;
+
+	list_for_each_entry(c, &interfaces, head) {
+		if (iface == c || c->ndp != RELAYD_RELAY ||
+				c->external == true)
+			continue;
+
+		ping6(addr, c);
 	}
-	return NULL;
 }
 
+static struct in6_addr last_solicited;
 
-// Modified our own neighbor-entries
-static void modify_neighbor(struct in6_addr *addr,
-		struct interface *iface, bool add)
+static void handle_rtnl_event(struct odhcpd_event *e)
 {
-	if (!addr || (void*)addr == (void*)iface)
-		return;
+	struct event_socket *ev_sock = container_of(e, struct event_socket, ev);
 
-	struct ndp_neighbor *n = find_neighbor(addr, true);
-	if (!add) { // Delete action
-		if (n && (!n->iface || n->iface == iface))
-			free_neighbor(n);
-	} else if (!n) { // No entry yet, add one if possible
-		if (neighbor_count >= NDP_MAX_NEIGHBORS ||
-				!(n = malloc(sizeof(*n))))
-			return;
-
-		n->len = 128;
-		n->addr = *addr;
-		n->iface = iface;
-		if (!n->iface)
-			time(&n->timeout);
-		list_add(&n->head, &neighbors);
-		++neighbor_count;
-		setup_route(addr, n->iface, add);
-	} else if (n->iface == iface) {
-		if (!n->iface)
-			time(&n->timeout);
-	} else if (iface && (!n->iface ||
-			(!iface->external && n->iface->external))) {
-		setup_route(addr, n->iface, false);
-		n->iface = iface;
-		setup_route(addr, n->iface, add);
-	}
-	// TODO: In case a host switches interfaces we might want
-	// to set its old neighbor entry to NUD_STALE and ping it
-	// on the old interface to confirm if the MACs match.
+	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 void handle_rtnetlink(_unused void *addr, void *data, size_t len,
-		_unused struct interface *iface)
+static int cb_rtnl_valid(struct nl_msg *msg, _unused void *arg)
 {
-	for (struct nlmsghdr *nh = data; NLMSG_OK(nh, len);
-			nh = NLMSG_NEXT(nh, len)) {
-		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);
-
-		// Family and ifindex are on the same offset for NEIGH and ADDR
-		if (NLMSG_PAYLOAD(nh, 0) < sizeof(*ndm)
-				|| ndm->ndm_family != AF_INET6)
-			continue; //
-
-		// Lookup interface
-		struct interface *iface;
-		if (!(iface = odhcpd_get_interface_by_index(ndm->ndm_ifindex)))
-			continue;
+	struct nlmsghdr *hdr = nlmsg_hdr(msg);
+	struct in6_addr *addr = NULL;
+	struct interface *iface = NULL;
+	bool add = false;
+	char ipbuf[INET6_ADDRSTRLEN];
 
-		// Data to retrieve
-		size_t rta_offset = (is_addr) ? sizeof(*ifa) : sizeof(*ndm);
-		uint16_t atype = (is_addr) ? IFA_ADDRESS : NDA_DST;
-		ssize_t alen = NLMSG_PAYLOAD(nh, rta_offset);
-		struct in6_addr *addr = NULL;
+	switch (hdr->nlmsg_type) {
+	case RTM_NEWROUTE:
+	case RTM_DELROUTE: {
+		struct rtmsg *rtm = nlmsg_data(hdr);
 
-		for (struct rtattr *rta = (void*)(((uint8_t*)ndm) + rta_offset);
-				RTA_OK(rta, alen); rta = RTA_NEXT(rta, alen))
-			if (rta->rta_type == atype &&
-					RTA_PAYLOAD(rta) >= sizeof(*addr))
-				addr = RTA_DATA(rta);
+		if (!nlmsg_valid_hdr(hdr, sizeof(*rtm)) ||
+				rtm->rtm_family != AF_INET6)
+			return NL_SKIP;
 
-		// Address not specified or unrelated
+		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))
-			continue;
+			return NL_SKIP;
 
-		// Check for states
-		bool add;
-		if (is_addr)
-			add = (nh->nlmsg_type == RTM_NEWADDR);
-		else
-			add = (nh->nlmsg_type == RTM_NEWNEIGH && (ndm->ndm_state &
-				(NUD_REACHABLE | NUD_STALE | NUD_DELAY | NUD_PROBE
-						| NUD_PERMANENT | NUD_NOARP)));
+		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 (iface->ndp == RELAYD_RELAY)
-			modify_neighbor(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 (is_addr && iface->ra == RELAYD_SERVER)
-			raise(SIGUSR1); // Inform about a change in addresses
+		if (!nlmsg_valid_hdr(hdr, sizeof(*ndm)) ||
+				ndm->ndm_family != AF_INET6)
+			return NL_SKIP;
 
-		if (is_addr && iface->dhcpv6 == RELAYD_SERVER)
-			iface->ia_reconf = true;
+		iface = odhcpd_get_interface_by_index(ndm->ndm_ifindex);
+		if (!iface || iface->ndp != RELAYD_RELAY)
+			return (iface ? NL_OK : NL_SKIP);
 
-		if (iface->ndp == RELAYD_RELAY && is_addr && iface->master) {
-			// Replay address changes on all slave interfaces
-			nh->nlmsg_flags = NLM_F_REQUEST;
+		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);
+			}
 
-			if (nh->nlmsg_type == RTM_NEWADDR)
-				nh->nlmsg_flags |= NLM_F_CREATE | NLM_F_REPLACE;
+			return NL_OK;
+		}
 
-			struct interface *c;
-			list_for_each_entry(c, &interfaces, head) {
-				if (c->ndp == RELAYD_RELAY && !c->master) {
-					ifa->ifa_index = c->ifindex;
-					send(rtnl_event.uloop.fd, nh, nh->nlmsg_len, MSG_DONTWAIT);
-				}
+		if (add && !(ndm->ndm_state &
+				(NUD_REACHABLE | NUD_STALE | NUD_DELAY | NUD_PROBE |
+				 NUD_PERMANENT | NUD_NOARP))) {
+			if (!IN6_ARE_ADDR_EQUAL(&last_solicited, addr)) {
+				last_solicited = *addr;
+				setup_ping6(addr, iface);
 			}
+
+			return NL_OK;
 		}
 
-		/* TODO: See if this is required for optimal operation
-		// Keep neighbor entries alive so we don't loose routes
-		 */
-		if (add && (ndm->ndm_state & NUD_STALE))
-			ping6(addr, iface);
+		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_addr_table();
+	return;
+
+err:
+	odhcpd_deregister(e);
 }