X-Git-Url: https://git.decadent.org.uk/gitweb/?p=odhcp6c.git;a=blobdiff_plain;f=src%2Fra.c;h=560552fcbd5bb4149bb9f2df8043bd30394ee76a;hp=c8ccb888f8856172ff58f280625b5005b61ab356;hb=6cda10d0b5f43234b2fefdf1ab94ee341878d010;hpb=c570ee307de12e47e8a370fb66d8f99f14d4b064

diff --git a/src/ra.c b/src/ra.c
index c8ccb88..560552f 100644
--- a/src/ra.c
+++ b/src/ra.c
@@ -1,5 +1,5 @@
 /**
- * Copyright (C) 2012-2013 Steven Barth <steven@midlink.org>
+ * Copyright (C) 2012-2014 Steven Barth <steven@midlink.org>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License v2 as published by
@@ -13,6 +13,7 @@
  */
 
 #include <fcntl.h>
+#include <ifaddrs.h>
 #include <stdio.h>
 #include <signal.h>
 #include <string.h>
@@ -24,6 +25,7 @@
 #include <net/if.h>
 #include <arpa/inet.h>
 #include <sys/socket.h>
+#include <sys/types.h>
 #include <netinet/in.h>
 #include <netinet/icmp6.h>
 
@@ -59,13 +61,23 @@ int ra_init(const char *ifname, const struct in6_addr *ifid)
 {
 	const pid_t ourpid = getpid();
 	sock = socket(AF_INET6, SOCK_RAW | SOCK_CLOEXEC, IPPROTO_ICMPV6);
+	if (sock < 0)
+		return -1;
+
 	if_index = if_nametoindex(ifname);
+	if (!if_index)
+		return -1;
+
 	strncpy(if_name, ifname, sizeof(if_name) - 1);
 	lladdr = *ifid;
 
 	rtnl = socket(AF_NETLINK, SOCK_DGRAM | SOCK_CLOEXEC, NETLINK_ROUTE);
+	if (rtnl < 0)
+		return -1;
+
 	struct sockaddr_nl rtnl_kernel = { .nl_family = AF_NETLINK };
-	connect(rtnl, (const struct sockaddr*)&rtnl_kernel, sizeof(rtnl_kernel));
+	if (connect(rtnl, (const struct sockaddr*)&rtnl_kernel, sizeof(rtnl_kernel)) < 0)
+		return -1;
 
 	int val = RTNLGRP_LINK;
 	setsockopt(rtnl, SOL_NETLINK, NETLINK_ADD_MEMBERSHIP, &val, sizeof(val));
@@ -185,27 +197,66 @@ bool ra_link_up(void)
 	return ret;
 }
 
+static bool ra_icmpv6_valid(struct sockaddr_in6 *source, int hlim, uint8_t *data, size_t len)
+{
+	struct icmp6_hdr *hdr = (struct icmp6_hdr*)data;
+	struct icmpv6_opt *opt, *end = (struct icmpv6_opt*)&data[len];
+
+	if (hlim != 255 || len < sizeof(*hdr) || hdr->icmp6_code)
+		return false;
+
+	switch (hdr->icmp6_type) {
+	case ND_ROUTER_ADVERT:
+		if (!IN6_IS_ADDR_LINKLOCAL(&source->sin6_addr))
+			return false;
+
+		opt = (struct icmpv6_opt*)((struct nd_router_advert*)data + 1);
+		break;
+
+	default:
+		return false;
+	}
+
+	icmpv6_for_each_option(opt, opt, end)
+		;
+
+	return opt == end;
+}
+
 bool ra_process(void)
 {
 	bool found = false;
 	bool changed = false;
+	bool has_lladdr = !IN6_IS_ADDR_UNSPECIFIED(&lladdr);
 	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};
+	struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT, 0, 0, IN6ADDR_ANY_INIT, 0, 0, 0, 0, 0, 0};
 	const struct in6_addr any = IN6ADDR_ANY_INIT;
 
-	if (IN6_IS_ADDR_UNSPECIFIED(&lladdr)) {
+	if (!has_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);
+		struct ifaddrs *ifaddr, *ifa;
+
+		if (getifaddrs(&ifaddr) == 0) {
+			for (ifa = ifaddr; ifa != NULL; ifa = ifa->ifa_next) {
+				struct sockaddr_in6 *addr;
+
+				if (ifa->ifa_addr == NULL || ifa->ifa_addr->sa_family != AF_INET6)
+					continue;
+
+				addr = (struct sockaddr_in6*)ifa->ifa_addr;
+
+				if (!IN6_IS_ADDR_LINKLOCAL(&addr->sin6_addr))
+					continue;
+
+				if (!strcmp(ifa->ifa_name, if_name)) {
+					lladdr = addr->sin6_addr;
+					has_lladdr = true;
 					break;
 				}
 			}
-			fclose(fp);
+
+			freeifaddrs(ifaddr);
 		}
 	}
 
@@ -216,9 +267,10 @@ bool ra_process(void)
 				cmsg_buf, sizeof(cmsg_buf), 0};
 
 		ssize_t len = recvmsg(sock, &msg, MSG_DONTWAIT);
-		if (len < 0)
+		if (len <= 0)
 			break;
-		else if (len < (ssize_t)sizeof(*adv))
+
+		if (!has_lladdr)
 			continue;
 
 		int hlim = 0;
@@ -228,7 +280,7 @@ bool ra_process(void)
 					ch->cmsg_type == IPV6_HOPLIMIT)
 				memcpy(&hlim, CMSG_DATA(ch), sizeof(hlim));
 
-		if (hlim != 255)
+		if (!ra_icmpv6_valid(&from, hlim, buf, len))
 			continue;
 
 		// Stop sending solicits
@@ -254,6 +306,10 @@ bool ra_process(void)
 		entry.preferred = entry.valid;
 		changed |= odhcp6c_update_entry(STATE_RA_ROUTE, &entry);
 
+		// Parse hoplimit
+		if (adv->nd_ra_curhoplimit)
+			update_proc("conf", "hop_limit", adv->nd_ra_curhoplimit);
+
 		// Parse ND parameters
 		if (ntohl(adv->nd_ra_reachable) <= 3600000)
 			update_proc("neigh", "base_reachable_time_ms", ntohl(adv->nd_ra_reachable));