ra/dhcpv6: unify address change handling

4 files changed, 130 insertions, 116 deletions

diff --git a/src/dhcpv6-ia.c b/src/dhcpv6-ia.c
index 6ea49b0..c5f8783 100644
--- a/src/dhcpv6-ia.c
+++ b/src/dhcpv6-ia.c
@@ -34,7 +34,6 @@
 #include <sys/timerfd.h>
 
 
-static void update(struct interface *iface);
 static void reconf_timer(struct uloop_timeout *event);
 static struct uloop_timeout reconf_event = {.cb = reconf_timer};
 static uint32_t serial = 0;
@@ -89,8 +88,6 @@ int setup_dhcpv6_ia_interface(struct interface *iface, bool enable)
 			list_add(&border->head, &iface->ia_assignments);
 		}
 
-		update(iface);
-
 		// Parse static entries
 		struct lease *lease;
 		list_for_each_entry(lease, &leases, head) {
@@ -556,106 +553,73 @@ static bool assign_na(struct interface *iface, struct dhcpv6_assignment *assign)
 	return false;
 }
 
-
-static int prefixcmp(const void *va, const void *vb)
+void dhcpv6_ia_preupdate(struct interface *iface)
 {
-	const struct odhcpd_ipaddr *a = va, *b = vb;
-	uint32_t a_pref = ((a->addr.s6_addr[0] & 0xfe) != 0xfc) ? a->preferred : 1;
-	uint32_t b_pref = ((b->addr.s6_addr[0] & 0xfe) != 0xfc) ? b->preferred : 1;
-	return (a_pref < b_pref) ? 1 : (a_pref > b_pref) ? -1 : 0;
-}
+	if (iface->dhcpv6 != RELAYD_SERVER)
+		return;
 
+	struct dhcpv6_assignment *c, *border = list_last_entry(
+			&iface->ia_assignments, struct dhcpv6_assignment, head);
+	list_for_each_entry(c, &iface->ia_assignments, head)
+		if (c != border && !iface->managed)
+			apply_lease(iface, c, false);
+}
 
-static void update(struct interface *iface)
+void dhcpv6_ia_postupdate(struct interface *iface, time_t now)
 {
-	struct odhcpd_ipaddr addr[8];
-	memset(addr, 0, sizeof(addr));
-	int len = odhcpd_get_interface_addresses(iface->ifindex, addr, 8);
-
-	if (len < 0)
+	if (iface->dhcpv6 != RELAYD_SERVER)
 		return;
 
-	qsort(addr, len, sizeof(*addr), prefixcmp);
-
-	time_t now = odhcpd_time();
 	int minprefix = -1;
-
-	for (int i = 0; i < len; ++i) {
-		if (addr[i].preferred > 0 && addr[i].prefix < 64 &&
-				addr[i].prefix > minprefix)
-			minprefix = addr[i].prefix;
-
-		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;
+	for (size_t i = 0; i < iface->ia_addr_len; ++i) {
+		if (iface->ia_addr[i].preferred > now &&
+				iface->ia_addr[i].prefix < 64 &&
+				iface->ia_addr[i].prefix > minprefix)
+			minprefix = iface->ia_addr[i].prefix;
 	}
 
-	struct dhcpv6_assignment *border = list_last_entry(&iface->ia_assignments, struct dhcpv6_assignment, head);
+	struct dhcpv6_assignment *border = list_last_entry(
+			&iface->ia_assignments, struct dhcpv6_assignment, head);
 	if (minprefix > 32 && minprefix <= 64)
 		border->assigned = 1U << (64 - minprefix);
 	else
 		border->assigned = 0;
 
-	bool change = len != (int)iface->ia_addr_len;
-	for (int i = 0; !change && i < len; ++i)
-		if (addr[i].addr.s6_addr32[0] != iface->ia_addr[i].addr.s6_addr32[0] ||
-				addr[i].addr.s6_addr32[1] != iface->ia_addr[i].addr.s6_addr32[1] ||
-				(addr[i].preferred > 0) != (iface->ia_addr[i].preferred > 0) ||
-				(addr[i].valid > (uint32_t)now + 7200) !=
-						(iface->ia_addr[i].valid > (uint32_t)now + 7200))
-			change = true;
-
-	if (change) {
-		struct dhcpv6_assignment *c;
-		list_for_each_entry(c, &iface->ia_assignments, head)
-			if (c != border && !iface->managed)
-				apply_lease(iface, c, false);
-	}
-
-	memcpy(iface->ia_addr, addr, len * sizeof(*addr));
-	iface->ia_addr_len = len;
+	struct list_head reassign = LIST_HEAD_INIT(reassign);
+	struct dhcpv6_assignment *c, *d;
+	list_for_each_entry_safe(c, d, &iface->ia_assignments, head) {
+		if (c->clid_len == 0 || c->valid_until < now || c->managed_size)
+			continue;
 
-	if (change) { // Addresses / prefixes have changed
-		struct list_head reassign = LIST_HEAD_INIT(reassign);
-		struct dhcpv6_assignment *c, *d;
-		list_for_each_entry_safe(c, d, &iface->ia_assignments, head) {
-			if (c->clid_len == 0 || c->valid_until < now || c->managed_size)
-				continue;
+		if (c->length < 128 && c->assigned >= border->assigned && c != border)
+			list_move(&c->head, &reassign);
+		else if (c != border)
+			apply_lease(iface, c, true);
 
-			if (c->length < 128 && c->assigned >= border->assigned && c != border)
-				list_move(&c->head, &reassign);
-			else if (c != border)
-				apply_lease(iface, c, true);
-
-			if (c->accept_reconf && c->reconf_cnt == 0) {
-				c->reconf_cnt = 1;
-				c->reconf_sent = now;
-				send_reconf(iface, c);
-
-				// Leave all other assignments of that client alone
-				struct dhcpv6_assignment *a;
-				list_for_each_entry(a, &iface->ia_assignments, head)
-					if (a != c && a->clid_len == c->clid_len &&
-							!memcmp(a->clid_data, c->clid_data, a->clid_len))
-						c->reconf_cnt = INT_MAX;
-			}
+		if (c->accept_reconf && c->reconf_cnt == 0) {
+			c->reconf_cnt = 1;
+			c->reconf_sent = now;
+			send_reconf(iface, c);
+
+			// Leave all other assignments of that client alone
+			struct dhcpv6_assignment *a;
+			list_for_each_entry(a, &iface->ia_assignments, head)
+				if (a != c && a->clid_len == c->clid_len &&
+						!memcmp(a->clid_data, c->clid_data, a->clid_len))
+					c->reconf_cnt = INT_MAX;
 		}
+	}
 
-		while (!list_empty(&reassign)) {
-			c = list_first_entry(&reassign, struct dhcpv6_assignment, head);
-			list_del(&c->head);
-			if (!assign_pd(iface, c)) {
-				c->assigned = 0;
-				list_add(&c->head, &iface->ia_assignments);
-			}
+	while (!list_empty(&reassign)) {
+		c = list_first_entry(&reassign, struct dhcpv6_assignment, head);
+		list_del(&c->head);
+		if (!assign_pd(iface, c)) {
+			c->assigned = 0;
+			list_add(&c->head, &iface->ia_assignments);
 		}
-
-		dhcpv6_write_statefile();
 	}
+
+	dhcpv6_write_statefile();
 }
 
 
@@ -1009,8 +973,6 @@ ssize_t dhcpv6_handle_ia(uint8_t *buf, size_t buflen, struct interface *iface,
 	if (!clid_data || !clid_len || clid_len > 130)
 		goto out;
 
-	update(iface);
-
 	struct dhcpv6_assignment *first = NULL;
 	dhcpv6_for_each_option(start, end, otype, olen, odata) {
 		bool is_pd = (otype == DHCPV6_OPT_IA_PD);
diff --git a/src/dhcpv6.h b/src/dhcpv6.h
index 09aa6f1..d9f42c8 100644
--- a/src/dhcpv6.h
+++ b/src/dhcpv6.h
@@ -14,6 +14,7 @@
 #pragma once
 
 #include <libubox/ustream.h>
+#include "odhcpd.h"
 
 #define ALL_DHCPV6_RELAYS {{{0xff, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,\
 		0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x02}}}
@@ -181,3 +182,5 @@ ssize_t dhcpv6_handle_ia(uint8_t *buf, size_t buflen, struct interface *iface,
 int dhcpv6_ia_init(void);
 int setup_dhcpv6_ia_interface(struct interface *iface, bool enable);
 void dhcpv6_write_statefile(void);
+void dhcpv6_ia_preupdate(struct interface *iface);
+void dhcpv6_ia_postupdate(struct interface *iface, time_t now);
diff --git a/src/ndp.c b/src/ndp.c
index 2aa55be..7f63f96 100644
--- a/src/ndp.c
+++ b/src/ndp.c
@@ -29,6 +29,7 @@
 #include <linux/rtnetlink.h>
 #include <linux/filter.h>
 #include "router.h"
+#include "dhcpv6.h"
 #include "ndp.h"
 
 
@@ -272,6 +273,58 @@ static void setup_route(struct in6_addr *addr, struct interface *iface, bool add
 		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 = ((a->addr.s6_addr[0] & 0xfe) != 0xfc) ? a->preferred : 1;
+	uint32_t b_pref = ((b->addr.s6_addr[0] & 0xfe) != 0xfc) ? b->preferred : 1;
+	return (a_pref < b_pref) ? 1 : (a_pref > b_pref) ? -1 : 0;
+}
+
+// Check address update
+static void check_updates(struct interface *iface)
+{
+	struct odhcpd_ipaddr addr[8] = {{IN6ADDR_ANY_INIT, 0, 0, 0, 0}};
+	time_t now = odhcpd_time();
+	ssize_t len = odhcpd_get_interface_addresses(iface->ifindex, addr, 8);
+
+	if (len < 0)
+		return;
+
+	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)
+		raise(SIGUSR1);
+}
+
 
 // Handler for neighbor cache entries from the kernel. This is our source
 // to learn and unlearn hosts on interfaces.
@@ -412,8 +465,7 @@ static void handle_rtnetlink(_unused void *addr, void *data, size_t len,
 		}
 
 		if (is_addr) {
-			if (iface->ra == RELAYD_SERVER)
-				raise(SIGUSR1); // Inform about a change in addresses
+			check_updates(iface);
 
 			if (iface->dhcpv6 == RELAYD_SERVER)
 				iface->ia_reconf = true;
diff --git a/src/router.c b/src/router.c
index 7e666f1..36f6ae7 100644
--- a/src/router.c
+++ b/src/router.c
@@ -114,7 +114,7 @@ int setup_router_interface(struct interface *iface, bool enable)
 			forward_router_solicitation(iface);
 		} else if (iface->ra == RELAYD_SERVER && !iface->master) {
 			iface->timer_rs.cb = trigger_router_advert;
-			trigger_router_advert(&iface->timer_rs);
+			uloop_timeout_set(&iface->timer_rs, 1000);
 		}
 
 		if (iface->ra == RELAYD_RELAY || (iface->ra == RELAYD_SERVER && !iface->master))
@@ -209,6 +209,7 @@ static bool parse_routes(struct odhcpd_ipaddr *n, ssize_t len)
 // Router Advert server mode
 static uint64_t send_router_advert(struct interface *iface, const struct in6_addr *from)
 {
+	time_t now = odhcpd_time();
 	int mtu = odhcpd_get_interface_config(iface->ifname, "mtu");
 	int hlim = odhcpd_get_interface_config(iface->ifname, "hop_limit");
 
@@ -219,7 +220,7 @@ static uint64_t send_router_advert(struct interface *iface, const struct in6_add
 		struct nd_router_advert h;
 		struct icmpv6_opt lladdr;
 		struct nd_opt_mtu mtu;
-		struct nd_opt_prefix_info prefix[RELAYD_MAX_PREFIXES];
+		struct nd_opt_prefix_info prefix[sizeof(iface->ia_addr) / sizeof(*iface->ia_addr)];
 	} adv = {
 		.h = {{.icmp6_type = ND_ROUTER_ADVERT, .icmp6_code = 0}, 0, 0},
 		.lladdr = {ND_OPT_SOURCE_LINKADDR, 1, {0}},
@@ -242,21 +243,21 @@ static uint64_t send_router_advert(struct interface *iface, const struct in6_add
 	odhcpd_get_mac(iface, adv.lladdr.data);
 
 	// If not currently shutting down
-	struct odhcpd_ipaddr addrs[RELAYD_MAX_PREFIXES];
+	struct odhcpd_ipaddr *addrs = NULL;
 	ssize_t ipcnt = 0;
-	uint64_t minvalid = UINT64_MAX;
-	uint64_t maxvalid = 0;
+	int64_t minvalid = INT64_MAX;
+	int64_t maxvalid = 0;
 
 	// If not shutdown
 	if (iface->timer_rs.cb) {
-		ipcnt = odhcpd_get_interface_addresses(iface->ifindex,
-				addrs, ARRAY_SIZE(addrs));
+		addrs = iface->ia_addr;
+		ipcnt = iface->ia_addr_len;
 
 		// Check default route
-		if (iface->default_router > 1)
-			adv.h.nd_ra_router_lifetime = htons(iface->default_router);
 		if (parse_routes(addrs, ipcnt))
 			adv.h.nd_ra_router_lifetime = htons(1);
+		if (iface->default_router > 1)
+			adv.h.nd_ra_router_lifetime = htons(iface->default_router);
 	}
 
 	// Construct Prefix Information options
@@ -268,15 +269,9 @@ static uint64_t send_router_advert(struct interface *iface, const struct in6_add
 
 	for (ssize_t i = 0; i < ipcnt; ++i) {
 		struct odhcpd_ipaddr *addr = &addrs[i];
-		if (addr->prefix > 96)
+		if (addr->prefix > 96 || addr->valid <= now)
 			continue; // Address not suitable
 
-		if (addr->preferred > MaxValidTime)
-			addr->preferred = MaxValidTime;
-
-		if (addr->valid > MaxValidTime)
-			addr->valid = MaxValidTime;
-
 		struct nd_opt_prefix_info *p = NULL;
 		for (size_t i = 0; i < cnt; ++i) {
 			if (addr->prefix == adv.prefix[i].nd_opt_pi_prefix_len &&
@@ -292,16 +287,16 @@ static uint64_t send_router_advert(struct interface *iface, const struct in6_add
 			p = &adv.prefix[cnt++];
 		}
 
-		if (addr->preferred > 0 &&
-				minvalid > 1000ULL * addr->valid)
-			minvalid = 1000ULL * addr->valid;
+		if (addr->preferred > now &&
+				minvalid > 1000LL * (addr->valid - now))
+			minvalid = 1000LL * (addr->valid - now);
 
-		if (maxvalid < 1000ULL * addr->valid)
-			maxvalid = 1000ULL * addr->valid;
+		if (maxvalid < 1000LL * (addr->valid - now))
+			maxvalid = 1000LL * (addr->valid - now);
 
 		if (((addr->addr.s6_addr[0] & 0xfe) != 0xfc || iface->default_router)
-				&& ntohs(adv.h.nd_ra_router_lifetime) < addr->valid)
-			adv.h.nd_ra_router_lifetime = htons(addr->valid);
+				&& ntohs(adv.h.nd_ra_router_lifetime) < addr->valid - now)
+			adv.h.nd_ra_router_lifetime = htons(addr->valid - now);
 
 		odhcpd_bmemcpy(&p->nd_opt_pi_prefix, &addr->addr,
 				(iface->ra_advrouter) ? 128 : addr->prefix);
@@ -315,11 +310,13 @@ static uint64_t send_router_advert(struct interface *iface, const struct in6_add
 			p->nd_opt_pi_flags_reserved |= ND_OPT_PI_FLAG_AUTO;
 		if (iface->ra_advrouter)
 			p->nd_opt_pi_flags_reserved |= ND_OPT_PI_FLAG_RADDR;
-		p->nd_opt_pi_valid_time = htonl(addr->valid);
-		p->nd_opt_pi_preferred_time = htonl(addr->preferred);
+		p->nd_opt_pi_valid_time = htonl(addr->valid - now);
+		if (addr->preferred > now)
+			p->nd_opt_pi_preferred_time = htonl(addr->preferred - now);
+
 
-		if (addr->preferred > dns_time) {
-			dns_time = addr->preferred;
+		if (addr->preferred - now > dns_time) {
+			dns_time = addr->preferred - now;
 			dns_pref = addr->addr;
 		}
 	}
@@ -395,7 +392,7 @@ static uint64_t send_router_advert(struct interface *iface, const struct in6_add
 
 	for (ssize_t i = 0; i < ipcnt; ++i) {
 		struct odhcpd_ipaddr *addr = &addrs[i];
-		if (addr->dprefix > 64 || addr->dprefix == 0 ||
+		if (addr->dprefix > 64 || addr->dprefix == 0 || addr->valid <= now ||
 				(addr->dprefix == 64 && addr->prefix == 64)) {
 			continue; // Address not suitable
 		} else if (addr->dprefix > 32) {
@@ -413,7 +410,7 @@ static uint64_t send_router_advert(struct interface *iface, const struct in6_add
 			routes[routes_cnt].flags |= ND_RA_PREF_LOW;
 		else if (iface->route_preference > 0)
 			routes[routes_cnt].flags |= ND_RA_PREF_HIGH;
-		routes[routes_cnt].lifetime = htonl(addr->valid);
+		routes[routes_cnt].lifetime = htonl(addr->valid - now);
 		routes[routes_cnt].addr[0] = addr->addr.s6_addr32[0];
 		routes[routes_cnt].addr[1] = addr->addr.s6_addr32[1];
 		routes[routes_cnt].addr[2] = 0;