X-Git-Url: http://git.archive.openwrt.org/?p=project%2Fodhcpd.git;a=blobdiff_plain;f=src%2Frouter.c;h=fffdc4c24ba3401c41e877a968efb7c092927373;hp=5abf1e6bff1d3682ae336a09f2ed88c08e1d5dd7;hb=58128dfdc336658477c248243af8c74a17d6e468;hpb=d02dc222e61e2464bf850a629030c8a8b9b57ee8

diff --git a/src/router.c b/src/router.c
index 5abf1e6..fffdc4c 100644
--- a/src/router.c
+++ b/src/router.c
@@ -130,12 +130,66 @@ static void sigusr1_refresh(_unused int signal)
 			uloop_timeout_set(&iface->timer_rs, 1000);
 }
 
+static int router_icmpv6_valid(struct sockaddr_in6 *source, uint8_t *data, size_t len)
+{
+	struct icmp6_hdr *hdr = (struct icmp6_hdr *)data;
+	struct icmpv6_opt *opt;
+	size_t optlen = len - sizeof(*hdr);
+
+	/* Hoplimit is already checked in odhcpd_receive_packets */
+	if (len < sizeof(*hdr))
+		return 0;
+
+	if (hdr->icmp6_code)
+		return 0;
+
+	switch (hdr->icmp6_type) {
+	case ND_ROUTER_ADVERT:
+		if (!IN6_IS_ADDR_LINKLOCAL(&source->sin6_addr))
+			return 0;
+
+		opt = (struct icmpv6_opt *)((struct nd_router_advert *)data + 1);
+		break;
+
+	case ND_ROUTER_SOLICIT:
+		opt = (struct icmpv6_opt *)((struct nd_router_solicit *)data + 1);
+		break;
+
+	default:
+		return 0;
+	}
+
+	while (optlen > 0) {
+		size_t l = opt->len << 3;
+
+		if (optlen < sizeof(*opt))
+			return 0;
+
+		if (l > optlen || l == 0)
+			return 0;
+
+		if (opt->type == ND_OPT_SOURCE_LINKADDR && IN6_IS_ADDR_UNSPECIFIED(&source->sin6_addr) &&
+			hdr->icmp6_type == ND_ROUTER_SOLICIT) {
+			return 0;
+		}
+
+		opt = (struct icmpv6_opt *)(((uint8_t *)opt) + l);
+
+		optlen -= l;
+	}
+
+	return 1;
+}
 
 // Event handler for incoming ICMPv6 packets
-static void handle_icmpv6(_unused void *addr, void *data, size_t len,
+static void handle_icmpv6(void *addr, void *data, size_t len,
 		struct interface *iface)
 {
 	struct icmp6_hdr *hdr = data;
+	
+	if (!router_icmpv6_valid(addr, data, len))
+		return;
+
 	if ((iface->ra == RELAYD_SERVER && !iface->master)) { // Server mode
 		if (hdr->icmp6_type == ND_ROUTER_SOLICIT)
 			send_router_advert(&iface->timer_rs);
@@ -219,7 +273,10 @@ static void send_router_advert(struct uloop_timeout *event)
 		.lladdr = {ND_OPT_SOURCE_LINKADDR, 1, {0}},
 		.mtu = {ND_OPT_MTU, 1, 0, htonl(mtu)},
 	};
-	adv.h.nd_ra_flags_reserved = ND_RA_FLAG_OTHER;
+
+	if (iface->dhcpv6)
+		adv.h.nd_ra_flags_reserved = ND_RA_FLAG_OTHER;
+
 	if (iface->managed >= RELAYD_MANAGED_MFLAG)
 		adv.h.nd_ra_flags_reserved |= ND_RA_FLAG_MANAGED;
 
@@ -353,6 +410,11 @@ static void send_router_advert(struct uloop_timeout *event)
 		uint32_t lifetime;
 		uint8_t name[];
 	} *search = alloca(sizeof(*search) + search_padded);
+
+	if (!search) {
+		syslog(LOG_ERR, "Alloca failed for dns search on interface %s", iface->ifname);
+		return;
+	}
 	search->type = ND_OPT_DNS_SEARCH;
 	search->len = search_len ? ((sizeof(*search) + search_padded) / 8) : 0;
 	search->pad = 0;