X-Git-Url: https://www.tinc-vpn.org/git/browse?a=blobdiff_plain;f=src%2Froute.c;h=4d7127959308cc0fcb6be76614469339202359ee;hb=a6448291834ca7419553a807ee367c719c2956d0;hp=a130e690d50f2b6cf14ef95160330c2592afe97e;hpb=f6e87ab476a0faf8b124ecaaa27f967d825e6457;p=tinc

diff --git a/src/route.c b/src/route.c
index a130e690..4d712795 100644
--- a/src/route.c
+++ b/src/route.c
@@ -59,6 +59,7 @@ static const size_t opt_size = sizeof(struct nd_opt_hdr);
 #define MAX(a, b) ((a) > (b) ? (a) : (b))
 #endif
 
+volatile int dummy;
 static timeout_t age_subnets_timeout;
 
 /* RFC 1071 */
@@ -80,6 +81,11 @@ static uint16_t inet_checksum(void *data, int len, uint16_t prevsum) {
 		checksum = (checksum & 0xFFFF) + (checksum >> 16);
 	}
 
+	// Work around a compiler optimization bug.
+	if(checksum) {
+		dummy = 1;
+	}
+
 	return ~checksum;
 }
 
@@ -406,6 +412,15 @@ static void clamp_mss(const node_t *source, const node_t *via, vpn_packet_t *pac
 		type = DATA(packet)[16] << 8 | DATA(packet)[17];
 	}
 
+	/* IP in IP (RFC 2003) packet */
+	if(type == ETH_P_IP && DATA(packet)[start + 9] == 4) {
+		start += 20;
+	}
+
+	if(packet->len <= start + 20) {
+		return;
+	}
+
 	if(type == ETH_P_IP && DATA(packet)[start + 9] == 6) {
 		start += (DATA(packet)[start] & 0xf) * 4;
 	} else if(type == ETH_P_IPV6 && DATA(packet)[start + 6] == 6) {
@@ -642,11 +657,13 @@ static void route_ipv4(node_t *source, vpn_packet_t *packet) {
 	}
 
 	if(!subnet->owner->status.reachable) {
-		return route_ipv4_unreachable(source, packet, ether_size, ICMP_DEST_UNREACH, ICMP_NET_UNREACH);
+		route_ipv4_unreachable(source, packet, ether_size, ICMP_DEST_UNREACH, ICMP_NET_UNREACH);
+		return;
 	}
 
 	if(forwarding_mode == FMODE_OFF && source != myself && subnet->owner != myself) {
-		return route_ipv4_unreachable(source, packet, ether_size, ICMP_DEST_UNREACH, ICMP_NET_ANO);
+		route_ipv4_unreachable(source, packet, ether_size, ICMP_DEST_UNREACH, ICMP_NET_ANO);
+		return;
 	}
 
 	if(decrement_ttl && source != myself && subnet->owner != myself)
@@ -666,7 +683,8 @@ static void route_ipv4(node_t *source, vpn_packet_t *packet) {
 	}
 
 	if(directonly && subnet->owner != via) {
-		return route_ipv4_unreachable(source, packet, ether_size, ICMP_DEST_UNREACH, ICMP_NET_ANO);
+		route_ipv4_unreachable(source, packet, ether_size, ICMP_DEST_UNREACH, ICMP_NET_ANO);
+		return;
 	}
 
 	if(via && packet->len > MAX(via->mtu, 590) && via != myself) {
@@ -733,11 +751,13 @@ static void route_ipv6(node_t *source, vpn_packet_t *packet) {
 	}
 
 	if(!subnet->owner->status.reachable) {
-		return route_ipv6_unreachable(source, packet, ether_size, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOROUTE);
+		route_ipv6_unreachable(source, packet, ether_size, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOROUTE);
+		return;
 	}
 
 	if(forwarding_mode == FMODE_OFF && source != myself && subnet->owner != myself) {
-		return route_ipv6_unreachable(source, packet, ether_size, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_ADMIN);
+		route_ipv6_unreachable(source, packet, ether_size, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_ADMIN);
+		return;
 	}
 
 	if(decrement_ttl && source != myself && subnet->owner != myself)
@@ -757,7 +777,8 @@ static void route_ipv6(node_t *source, vpn_packet_t *packet) {
 	}
 
 	if(directonly && subnet->owner != via) {
-		return route_ipv6_unreachable(source, packet, ether_size, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_ADMIN);
+		route_ipv6_unreachable(source, packet, ether_size, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_ADMIN);
+		return;
 	}
 
 	if(via && packet->len > MAX(via->mtu, 1294) && via != myself) {