X-Git-Url: https://git.decadent.org.uk/gitweb/?a=blobdiff_plain;f=src%2Fra.c;h=f41602a587e00b87d10299bbac62df785b873f11;hb=e1b11c518aded9136b4f44759c6e2a6be4161ee9;hp=9c1ed74d4ee4e89b90702ae8f33554ff34706bff;hpb=9c409ef5ce654ed5dd3ce706317eaac718a22983;p=odhcp6c.git

diff --git a/src/ra.c b/src/ra.c
index 9c1ed74..f41602a 100644
--- a/src/ra.c
+++ b/src/ra.c
@@ -67,6 +67,10 @@ int ra_init(const char *ifname, const struct in6_addr *ifid)
 	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));
 
@@ -75,21 +79,6 @@ int ra_init(const char *ifname, const struct in6_addr *ifid)
 	fcntl(sock, F_SETOWN, ourpid);
 	fcntl(sock, F_SETFL, fcntl(sock, F_GETFL) | O_ASYNC);
 
-	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);
-		}
-	}
-
 	// Send RS
 	signal(SIGALRM, ra_send_rs);
 	ra_send_rs(SIGALRM);
@@ -131,20 +120,49 @@ static void update_proc(const char *sect, const char *opt, uint32_t value)
 bool ra_process(void)
 {
 	bool found = false;
-	uint8_t buf[1500];
+	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};
 	const struct in6_addr any = IN6ADDR_ANY_INIT;
 
+	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);
+		}
+	}
+
 	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);
@@ -166,7 +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)
@@ -198,7 +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;
@@ -215,7 +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)
@@ -224,7 +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;
@@ -236,7 +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);
 				}
 			}
 		}
@@ -252,5 +270,5 @@ bool ra_process(void)
 	if (found)
 		odhcp6c_expire();
 
-	return found;
+	return found && changed;
 }