X-Git-Url: https://git.decadent.org.uk/gitweb/?a=blobdiff_plain;f=src%2Fra.c;h=c870279abae3f70730dc3aee17719a25168df726;hb=d77cbea57d1b7dd9c25421bb13c90e65bb54a6bc;hp=b1526aed6ccacaba046b10072fd8e8887628fb29;hpb=83114b179091cb080f09cf4142ee1c9949ea4e30;p=odhcp6c.git

diff --git a/src/ra.c b/src/ra.c
index b1526ae..c870279 100644
--- a/src/ra.c
+++ b/src/ra.c
@@ -34,7 +34,7 @@
 #include "ra.h"
 
 
-static int sock = -1, rtnl_sock = -1;
+static int sock = -1;
 static unsigned if_index = 0;
 static char if_name[IF_NAMESIZE] = {0};
 static volatile int rs_attempt = 0;
@@ -42,11 +42,12 @@ static struct in6_addr lladdr = IN6ADDR_ANY_INIT;
 
 static void ra_send_rs(int signal __attribute__((unused)));
 
-int ra_init(const char *ifname)
+int ra_init(const char *ifname, const struct in6_addr *ifid)
 {
 	sock = socket(AF_INET6, SOCK_RAW | SOCK_CLOEXEC, IPPROTO_ICMPV6);
 	if_index = if_nametoindex(ifname);
 	strncpy(if_name, ifname, sizeof(if_name) - 1);
+	lladdr = *ifid;
 
 	// Filter ICMPv6 package types
 	struct icmp6_filter filt;
@@ -66,6 +67,10 @@ int ra_init(const char *ifname)
 	val = 255;
 	setsockopt(sock, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &val, sizeof(val));
 
+	// Receive multicast hops
+	val = 1;
+	setsockopt(sock, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &val, sizeof(val));
+
 	// Bind to one device
 	setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen(ifname));
 
@@ -74,31 +79,6 @@ int ra_init(const char *ifname)
 	fcntl(sock, F_SETOWN, ourpid);
 	fcntl(sock, F_SETFL, fcntl(sock, F_GETFL) | O_ASYNC);
 
-	// Get LL-addr
-	FILE *fp = fopen("/proc/net/if_inet6", "r");
-	if (fp) {
-		char addrbuf[33], ifbuf[16];
-		while (fscanf(fp, "%32s %*x %*x %*x %*x %15s", addrbuf, ifbuf) == 2) {
-			if (!strcmp(ifbuf, if_name)) {
-				script_unhexlify((uint8_t*)&lladdr, sizeof(lladdr), addrbuf);
-				break;
-			}
-		}
-		fclose(fp);
-	}
-
-	// Open rtnetlink socket
-	rtnl_sock = socket(AF_NETLINK, SOCK_RAW | SOCK_CLOEXEC, NETLINK_ROUTE);
-	struct sockaddr_nl rtnl_kernel = { .nl_family = AF_NETLINK };
-	if (connect(rtnl_sock, (struct sockaddr*)&rtnl_kernel, sizeof(rtnl_kernel)))
-		return -1;
-	uint32_t group = RTNLGRP_IPV6_IFADDR;
-	setsockopt(rtnl_sock, SOL_NETLINK, NETLINK_ADD_MEMBERSHIP, &group, sizeof(group));
-
-	// Add async-mode
-	fcntl(rtnl_sock, F_SETOWN, ourpid);
-	fcntl(rtnl_sock, F_SETFL, fcntl(rtnl_sock, F_GETFL) | O_ASYNC);
-
 	// Send RS
 	signal(SIGALRM, ra_send_rs);
 	ra_send_rs(SIGALRM);
@@ -137,80 +117,52 @@ static void update_proc(const char *sect, const char *opt, uint32_t value)
 }
 
 
-static bool ra_deduplicate(const struct in6_addr *any, uint8_t length)
-{
-	struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT, length, 0, *any, 0, 0};
-	struct odhcp6c_entry *x = odhcp6c_find_entry(STATE_RA_PREFIX, &entry);
-	if (x && IN6_ARE_ADDR_EQUAL(&x->target, any)) {
-		odhcp6c_random(&x->target.s6_addr32[2], 2 * sizeof(uint32_t));
-	} else if (odhcp6c_find_entry(STATE_IA_NA, &entry)) {
-		dhcpv6_request(DHCPV6_MSG_DECLINE);
-		raise(SIGUSR2);
-	}
-
-	return !!x;
-}
-
-
-bool ra_rtnl_process(void)
+bool ra_process(void)
 {
 	bool found = false;
-	uint32_t elapsed = odhcp6c_elapsed();
-	uint8_t buf[8192];
-	while (true) {
-		ssize_t len = recv(rtnl_sock, buf, sizeof(buf), MSG_DONTWAIT);
-		if (len < 0)
-			break;
-
-		if (elapsed > 10)
-			continue;
+	bool changed = false;
+	uint8_t buf[1500], cmsg_buf[128];
+	struct nd_router_advert *adv = (struct nd_router_advert*)buf;
+	struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT, 0, 0, IN6ADDR_ANY_INIT, 0, 0, 0, 0, 0};
+	const struct in6_addr any = IN6ADDR_ANY_INIT;
 
-		for (struct nlmsghdr *nh = (struct nlmsghdr*)buf; NLMSG_OK(nh, (size_t)len);
-					nh = NLMSG_NEXT(nh, len)) {
-			struct ifaddrmsg *ifa = NLMSG_DATA(nh);
-			struct in6_addr *addr = NULL;
-			if (NLMSG_PAYLOAD(nh, 0) < sizeof(*ifa) || ifa->ifa_index != if_index ||
-					(nh->nlmsg_type == RTM_NEWADDR && !(ifa->ifa_flags & IFA_F_DADFAILED)) ||
-					(nh->nlmsg_type == RTM_DELADDR && !(ifa->ifa_flags & IFA_F_TENTATIVE)) ||
-					(nh->nlmsg_type != RTM_NEWADDR && nh->nlmsg_type != RTM_DELADDR))
-				continue;
-
-			ssize_t alen = NLMSG_PAYLOAD(nh, sizeof(*ifa));
-			for (struct rtattr *rta = (struct rtattr*)&ifa[1]; RTA_OK(rta, alen);
-					rta = RTA_NEXT(rta, alen))
-				if (rta->rta_type == IFA_ADDRESS && RTA_PAYLOAD(rta) >= sizeof(*addr))
-					addr = RTA_DATA(rta);
-
-			if (addr) {
-				char ipbuf[INET6_ADDRSTRLEN];
-				inet_ntop(AF_INET6, addr, ipbuf, sizeof(ipbuf));
-				syslog(LOG_WARNING, "duplicate address detected: %s (code: %u:%x)",
-						ipbuf, (unsigned)nh->nlmsg_type, (unsigned)ifa->ifa_flags);
-				found |= ra_deduplicate(addr, ifa->ifa_prefixlen);
+	if (IN6_IS_ADDR_UNSPECIFIED(&lladdr)) {
+		// Autodetect interface-id if not specified
+		FILE *fp = fopen("/proc/net/if_inet6", "r");
+		if (fp) {
+			char addrbuf[33], ifbuf[16];
+			while (fscanf(fp, "%32s %*x %*x %*x %*x %15s", addrbuf, ifbuf) == 2) {
+				if (!strcmp(ifbuf, if_name)) {
+					script_unhexlify((uint8_t*)&lladdr, sizeof(lladdr), addrbuf);
+					break;
+				}
 			}
+			fclose(fp);
 		}
 	}
-	return found;
-}
-
-
-bool ra_process(void)
-{
-	bool found = false;
-	uint8_t buf[1500];
-	struct nd_router_advert *adv = (struct nd_router_advert*)buf;
-	struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT, 0, 0, IN6ADDR_ANY_INIT, 0, 0};
-	const struct in6_addr any = IN6ADDR_ANY_INIT;
 
 	while (true) {
 		struct sockaddr_in6 from;
-		socklen_t from_len = sizeof(from);
-		ssize_t len = recvfrom(sock, buf, sizeof(buf), MSG_DONTWAIT, &from, &from_len);
+		struct iovec iov = {buf, sizeof(buf)};
+		struct msghdr msg = {&from, sizeof(from), &iov, 1,
+				cmsg_buf, sizeof(cmsg_buf), 0};
+
+		ssize_t len = recvmsg(sock, &msg, MSG_DONTWAIT);
 		if (len < 0)
 			break;
 		else if (len < (ssize_t)sizeof(*adv))
 			continue;
 
+		int hlim = 0;
+		for (struct cmsghdr *ch = CMSG_FIRSTHDR(&msg); ch != NULL;
+				ch = CMSG_NXTHDR(&msg, ch))
+			if (ch->cmsg_level == IPPROTO_IPV6 &&
+					ch->cmsg_type == IPV6_HOPLIMIT)
+				memcpy(&hlim, CMSG_DATA(ch), sizeof(hlim));
+
+		if (hlim != 255)
+			continue;
+
 		// Stop sending solicits
 		if (rs_attempt > 0) {
 			alarm(0);
@@ -232,7 +184,7 @@ bool ra_process(void)
 			entry.priority = pref_to_priority(0);
 		entry.valid = router_valid;
 		entry.preferred = entry.valid;
-		odhcp6c_update_entry(STATE_RA_ROUTE, &entry);
+		changed |= odhcp6c_update_entry(STATE_RA_ROUTE, &entry);
 
 		// Parse ND parameters
 		if (ntohl(adv->nd_ra_reachable) <= 3600000)
@@ -264,7 +216,7 @@ bool ra_process(void)
 					continue;
 
 				if (entry.priority > 0)
-					odhcp6c_update_entry(STATE_RA_ROUTE, &entry);
+					changed |= odhcp6c_update_entry(STATE_RA_ROUTE, &entry);
 			} else if (opt->type == ND_OPT_PREFIX_INFORMATION && opt->len == 4) {
 				struct nd_opt_prefix_info *pinfo = (struct nd_opt_prefix_info*)opt;
 				entry.router = any;
@@ -281,7 +233,7 @@ bool ra_process(void)
 					continue;
 
 				if (pinfo->nd_opt_pi_flags_reserved & ND_OPT_PI_FLAG_ONLINK)
-					odhcp6c_update_entry_safe(STATE_RA_ROUTE, &entry, 7200);
+					changed |= odhcp6c_update_entry_safe(STATE_RA_ROUTE, &entry, 7200);
 
 				if (!(pinfo->nd_opt_pi_flags_reserved & ND_OPT_PI_FLAG_AUTO) ||
 						pinfo->nd_opt_pi_prefix_len != 64)
@@ -290,7 +242,7 @@ bool ra_process(void)
 				entry.target.s6_addr32[2] = lladdr.s6_addr32[2];
 				entry.target.s6_addr32[3] = lladdr.s6_addr32[3];
 
-				odhcp6c_update_entry_safe(STATE_RA_PREFIX, &entry, 7200);
+				changed |= odhcp6c_update_entry_safe(STATE_RA_PREFIX, &entry, 7200);
 			} else if (opt->type == ND_OPT_RECURSIVE_DNS && opt->len > 2) {
 				entry.router = from.sin6_addr;
 				entry.priority = 0;
@@ -302,7 +254,7 @@ bool ra_process(void)
 				for (ssize_t i = 0; i < (opt->len - 1) / 2; ++i) {
 					memcpy(&entry.target, &opt->data[6 + i * sizeof(entry.target)],
 							sizeof(entry.target));
-					odhcp6c_update_entry(STATE_RA_DNS, &entry);
+					changed |= odhcp6c_update_entry(STATE_RA_DNS, &entry);
 				}
 			}
 		}
@@ -318,5 +270,5 @@ bool ra_process(void)
 	if (found)
 		odhcp6c_expire();
 
-	return found;
+	return found && changed;
 }