X-Git-Url: https://tinc-vpn.org/git/browse?a=blobdiff_plain;f=src%2Froute.c;h=7bb9996179e6de082fbb736deb2864ff4eb91b65;hb=6bc5d626a8726fc23365ee705761a3c666a08ad4;hp=cec35cae13b37b51fbeb5d7596bdafc00815aa73;hpb=0b8b23e0dd7219344543f135ca0aeba8a4a42d48;p=tinc

diff --git a/src/route.c b/src/route.c
index cec35cae..7bb99961 100644
--- a/src/route.c
+++ b/src/route.c
@@ -59,7 +59,7 @@ static const size_t opt_size = sizeof(struct nd_opt_hdr);
 #define MAX(a, b) ((a) > (b) ? (a) : (b))
 #endif
 
-static struct event age_subnets_event;
+static timeout_t age_subnets_timeout;
 
 /* RFC 1071 */
 
@@ -71,7 +71,7 @@ static uint16_t inet_checksum(void *data, int len, uint16_t prevsum) {
 		checksum += *p++;
 		len -= 2;
 	}
-	
+
 	if(len)
 		checksum += *(uint8_t *)p;
 
@@ -84,13 +84,12 @@ static uint16_t inet_checksum(void *data, int len, uint16_t prevsum) {
 static bool ratelimit(int frequency) {
 	static time_t lasttime = 0;
 	static int count = 0;
-	time_t now = time(NULL);
-	
-	if(lasttime == now) {
+
+	if(lasttime == now.tv_sec) {
 		if(count >= frequency)
 			return true;
 	} else {
-		lasttime = now;
+		lasttime = now.tv_sec;
 		count = 0;
 	}
 
@@ -115,15 +114,22 @@ static void clamp_mss(const node_t *source, const node_t *via, vpn_packet_t *pac
 		mtu = via->mtu;
 
 	/* Find TCP header */
-	int start = 0;
+	int start = ether_size;
 	uint16_t type = packet->data[12] << 8 | packet->data[13];
 
-	if(type == ETH_P_IP && packet->data[23] == 6)
-		start = 14 + (packet->data[14] & 0xf) * 4;
-	else if(type == ETH_P_IPV6 && packet->data[20] == 6)
-		start = 14 + 40;
+	if(type == ETH_P_8021Q) {
+		start += 4;
+		type = packet->data[16] << 8 | packet->data[17];
+	}
 
-	if(!start || packet->len <= start + 20)
+	if(type == ETH_P_IP && packet->data[start + 9] == 6)
+		start += (packet->data[start] & 0xf) * 4;
+	else if(type == ETH_P_IPV6 && packet->data[start + 6] == 6)
+		start += 40;
+	else
+		return;
+
+	if(packet->len <= start + 20)
 		return;
 
 	/* Use data offset field to calculate length of options field */
@@ -162,7 +168,7 @@ static void clamp_mss(const node_t *source, const node_t *via, vpn_packet_t *pac
 
 		if(oldmss <= newmss)
 			break;
-		
+
 		logger(DEBUG_TRAFFIC, LOG_INFO, "Clamping MSS of packet from %s to %s to %d", source->name, via->name, newmss);
 
 		/* Update the MSS value and the checksum */
@@ -184,13 +190,12 @@ static void swap_mac_addresses(vpn_packet_t *packet) {
 	memcpy(&packet->data[0], &packet->data[6], sizeof tmp);
 	memcpy(&packet->data[6], &tmp, sizeof tmp);
 }
-	
-static void age_subnets(int fd, short events, void *data) {
+
+static void age_subnets(void *data) {
 	bool left = false;
-	time_t now = time(NULL);
 
 	for splay_each(subnet_t, s, myself->subnet_tree) {
-		if(s->expires && s->expires < now) {
+		if(s->expires && s->expires < now.tv_sec) {
 			if(debug_level >= DEBUG_TRAFFIC) {
 				char netstr[MAXNETSTR];
 				if(net2str(netstr, sizeof netstr, s))
@@ -209,7 +214,7 @@ static void age_subnets(int fd, short events, void *data) {
 	}
 
 	if(left)
-		event_add(&age_subnets_event, &(struct timeval){10, 0});
+		timeout_set(&age_subnets_timeout, &(struct timeval){10, rand() % 100000});
 }
 
 static void learn_mac(mac_t *address) {
@@ -236,9 +241,7 @@ static void learn_mac(mac_t *address) {
 			if(c->status.active)
 				send_add_subnet(c, subnet);
 
-		if(!timeout_initialized(&age_subnets_event))
-			timeout_set(&age_subnets_event, age_subnets, NULL);
-		event_add(&age_subnets_event, &(struct timeval){10, 0});
+		timeout_add(&age_subnets_timeout, age_subnets, NULL, &(struct timeval){10, rand() % 100000});
 	} else {
 		if(subnet->expires)
 			subnet->expires = time(NULL) + macexpire;
@@ -247,17 +250,17 @@ static void learn_mac(mac_t *address) {
 
 /* RFC 792 */
 
-static void route_ipv4_unreachable(node_t *source, vpn_packet_t *packet, uint8_t type, uint8_t code) {
+static void route_ipv4_unreachable(node_t *source, vpn_packet_t *packet, length_t ether_size, uint8_t type, uint8_t code) {
 	struct ip ip = {0};
 	struct icmp icmp = {0};
-	
+
 	struct in_addr ip_src;
 	struct in_addr ip_dst;
 	uint32_t oldlen;
 
 	if(ratelimit(3))
 		return;
-	
+
 	/* Swap Ethernet source and destination addresses */
 
 	swap_mac_addresses(packet);
@@ -267,7 +270,7 @@ static void route_ipv4_unreachable(node_t *source, vpn_packet_t *packet, uint8_t
 	memcpy(&ip, packet->data + ether_size, ip_size);
 
 	/* Remember original source and destination */
-	
+
 	ip_src = ip.ip_src;
 	ip_dst = ip.ip_dst;
 
@@ -278,13 +281,13 @@ static void route_ipv4_unreachable(node_t *source, vpn_packet_t *packet, uint8_t
 
 	if(oldlen >= IP_MSS - ip_size - icmp_size)
 		oldlen = IP_MSS - ip_size - icmp_size;
-	
+
 	/* Copy first part of original contents to ICMP message */
-	
+
 	memmove(packet->data + ether_size + ip_size + icmp_size, packet->data + ether_size, oldlen);
 
 	/* Fill in IPv4 header */
-	
+
 	ip.ip_v = 4;
 	ip.ip_hl = ip_size / 4;
 	ip.ip_tos = 0;
@@ -298,13 +301,13 @@ static void route_ipv4_unreachable(node_t *source, vpn_packet_t *packet, uint8_t
 	ip.ip_dst = ip_src;
 
 	ip.ip_sum = inet_checksum(&ip, ip_size, ~0);
-	
+
 	/* Fill in ICMP header */
-	
+
 	icmp.icmp_type = type;
 	icmp.icmp_code = code;
 	icmp.icmp_cksum = 0;
-	
+
 	icmp.icmp_cksum = inet_checksum(&icmp, icmp_size, ~0);
 	icmp.icmp_cksum = inet_checksum(packet->data + ether_size + ip_size + icmp_size, oldlen, icmp.icmp_cksum);
 
@@ -312,7 +315,7 @@ static void route_ipv4_unreachable(node_t *source, vpn_packet_t *packet, uint8_t
 
 	memcpy(packet->data + ether_size, &ip, ip_size);
 	memcpy(packet->data + ether_size + ip_size, &icmp, icmp_size);
-	
+
 	packet->len = ether_size + ip_size + icmp_size + oldlen;
 
 	send_packet(source, packet);
@@ -320,19 +323,19 @@ static void route_ipv4_unreachable(node_t *source, vpn_packet_t *packet, uint8_t
 
 /* RFC 791 */
 
-static void fragment_ipv4_packet(node_t *dest, vpn_packet_t *packet) {
+static void fragment_ipv4_packet(node_t *dest, vpn_packet_t *packet, length_t ether_size) {
 	struct ip ip;
 	vpn_packet_t fragment;
 	int len, maxlen, todo;
 	uint8_t *offset;
 	uint16_t ip_off, origf;
-	
+
 	memcpy(&ip, packet->data + ether_size, ip_size);
 	fragment.priority = packet->priority;
 
 	if(ip.ip_hl != ip_size / 4)
 		return;
-	
+
 	todo = ntohs(ip.ip_len) - ip_size;
 
 	if(ether_size + ip_size + todo != packet->len) {
@@ -347,7 +350,7 @@ static void fragment_ipv4_packet(node_t *dest, vpn_packet_t *packet) {
 	ip_off = ntohs(ip.ip_off);
 	origf = ip_off & ~IP_OFFMASK;
 	ip_off &= IP_OFFMASK;
-	
+
 	while(todo) {
 		len = todo > maxlen ? maxlen : todo;
 		memcpy(fragment.data + ether_size + ip_size, offset, len);
@@ -365,7 +368,7 @@ static void fragment_ipv4_packet(node_t *dest, vpn_packet_t *packet) {
 		send_packet(dest, &fragment);
 
 		ip_off += len / 8;
-	}	
+	}
 }
 
 static void route_ipv4_unicast(node_t *source, vpn_packet_t *packet) {
@@ -384,20 +387,20 @@ static void route_ipv4_unicast(node_t *source, vpn_packet_t *packet) {
 				dest.x[2],
 				dest.x[3]);
 
-		route_ipv4_unreachable(source, packet, ICMP_DEST_UNREACH, ICMP_NET_UNKNOWN);
+		route_ipv4_unreachable(source, packet, ether_size, ICMP_DEST_UNREACH, ICMP_NET_UNKNOWN);
 		return;
 	}
-	
+
 	if(subnet->owner == source) {
 		logger(DEBUG_TRAFFIC, LOG_WARNING, "Packet looping back to %s (%s)!", source->name, source->hostname);
 		return;
 	}
 
 	if(!subnet->owner->status.reachable)
-		return route_ipv4_unreachable(source, packet, ICMP_DEST_UNREACH, ICMP_NET_UNREACH);
+		return route_ipv4_unreachable(source, packet, ether_size, ICMP_DEST_UNREACH, ICMP_NET_UNREACH);
 
 	if(forwarding_mode == FMODE_OFF && source != myself && subnet->owner != myself)
-		return route_ipv4_unreachable(source, packet, ICMP_DEST_UNREACH, ICMP_NET_ANO);
+		return route_ipv4_unreachable(source, packet, ether_size, ICMP_DEST_UNREACH, ICMP_NET_ANO);
 
 	if(priorityinheritance)
 		packet->priority = packet->data[15];
@@ -408,24 +411,24 @@ static void route_ipv4_unicast(node_t *source, vpn_packet_t *packet) {
 		logger(DEBUG_TRAFFIC, LOG_ERR, "Routing loop for packet from %s (%s)!", source->name, source->hostname);
 		return;
 	}
-	
+
 	if(directonly && subnet->owner != via)
-		return route_ipv4_unreachable(source, packet, ICMP_DEST_UNREACH, ICMP_NET_ANO);
+		return route_ipv4_unreachable(source, packet, ether_size, ICMP_DEST_UNREACH, ICMP_NET_ANO);
 
 	if(via && packet->len > MAX(via->mtu, 590) && via != myself) {
 		logger(DEBUG_TRAFFIC, LOG_INFO, "Packet for %s (%s) length %d larger than MTU %d", subnet->owner->name, subnet->owner->hostname, packet->len, via->mtu);
 		if(packet->data[20] & 0x40) {
 			packet->len = MAX(via->mtu, 590);
-			route_ipv4_unreachable(source, packet, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED);
+			route_ipv4_unreachable(source, packet, ether_size, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED);
 		} else {
-			fragment_ipv4_packet(via, packet);
+			fragment_ipv4_packet(via, packet, ether_size);
 		}
 
 		return;
 	}
 
 	clamp_mss(source, via, packet);
- 
+
 	send_packet(subnet->owner, packet);
 }
 
@@ -445,21 +448,21 @@ static void route_ipv4(node_t *source, vpn_packet_t *packet) {
 
 /* RFC 2463 */
 
-static void route_ipv6_unreachable(node_t *source, vpn_packet_t *packet, uint8_t type, uint8_t code) {
+static void route_ipv6_unreachable(node_t *source, vpn_packet_t *packet, length_t ether_size, uint8_t type, uint8_t code) {
 	struct ip6_hdr ip6;
 	struct icmp6_hdr icmp6 = {0};
-	uint16_t checksum;	
+	uint16_t checksum;
 
 	struct {
-		struct in6_addr ip6_src;	/* source address */
-		struct in6_addr ip6_dst;	/* destination address */
+		struct in6_addr ip6_src;        /* source address */
+		struct in6_addr ip6_dst;        /* destination address */
 		uint32_t length;
 		uint32_t next;
 	} pseudo;
 
 	if(ratelimit(3))
 		return;
-	
+
 	/* Swap Ethernet source and destination addresses */
 
 	swap_mac_addresses(packet);
@@ -469,7 +472,7 @@ static void route_ipv6_unreachable(node_t *source, vpn_packet_t *packet, uint8_t
 	memcpy(&ip6, packet->data + ether_size, ip6_size);
 
 	/* Remember original source and destination */
-	
+
 	pseudo.ip6_src = ip6.ip6_dst;
 	pseudo.ip6_dst = ip6.ip6_src;
 
@@ -477,16 +480,16 @@ static void route_ipv6_unreachable(node_t *source, vpn_packet_t *packet, uint8_t
 
 	if(type == ICMP6_PACKET_TOO_BIG)
 		icmp6.icmp6_mtu = htonl(pseudo.length);
-	
+
 	if(pseudo.length >= IP_MSS - ip6_size - icmp6_size)
 		pseudo.length = IP_MSS - ip6_size - icmp6_size;
-	
+
 	/* Copy first part of original contents to ICMP message */
-	
+
 	memmove(packet->data + ether_size + ip6_size + icmp6_size, packet->data + ether_size, pseudo.length);
 
 	/* Fill in IPv6 header */
-	
+
 	ip6.ip6_flow = htonl(0x60000000UL);
 	ip6.ip6_plen = htons(icmp6_size + pseudo.length);
 	ip6.ip6_nxt = IPPROTO_ICMPV6;
@@ -495,18 +498,18 @@ static void route_ipv6_unreachable(node_t *source, vpn_packet_t *packet, uint8_t
 	ip6.ip6_dst = pseudo.ip6_dst;
 
 	/* Fill in ICMP header */
-	
+
 	icmp6.icmp6_type = type;
 	icmp6.icmp6_code = code;
 	icmp6.icmp6_cksum = 0;
 
 	/* Create pseudo header */
-		
+
 	pseudo.length = htonl(icmp6_size + pseudo.length);
 	pseudo.next = htonl(IPPROTO_ICMPV6);
 
 	/* Generate checksum */
-	
+
 	checksum = inet_checksum(&pseudo, sizeof pseudo, ~0);
 	checksum = inet_checksum(&icmp6, icmp6_size, checksum);
 	checksum = inet_checksum(packet->data + ether_size + ip6_size + icmp6_size, ntohl(pseudo.length) - icmp6_size, checksum);
@@ -517,9 +520,9 @@ static void route_ipv6_unreachable(node_t *source, vpn_packet_t *packet, uint8_t
 
 	memcpy(packet->data + ether_size, &ip6, ip6_size);
 	memcpy(packet->data + ether_size + ip6_size, &icmp6, icmp6_size);
-	
+
 	packet->len = ether_size + ip6_size + ntohl(pseudo.length);
-	
+
 	send_packet(source, packet);
 }
 
@@ -543,7 +546,7 @@ static void route_ipv6_unicast(node_t *source, vpn_packet_t *packet) {
 				ntohs(dest.x[6]),
 				ntohs(dest.x[7]));
 
-		route_ipv6_unreachable(source, packet, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_ADDR);
+		route_ipv6_unreachable(source, packet, ether_size, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_ADDR);
 		return;
 	}
 
@@ -553,30 +556,30 @@ static void route_ipv6_unicast(node_t *source, vpn_packet_t *packet) {
 	}
 
 	if(!subnet->owner->status.reachable)
-		return route_ipv6_unreachable(source, packet, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOROUTE);
+		return route_ipv6_unreachable(source, packet, ether_size, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOROUTE);
 
 	if(forwarding_mode == FMODE_OFF && source != myself && subnet->owner != myself)
-		return route_ipv6_unreachable(source, packet, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_ADMIN);
+		return route_ipv6_unreachable(source, packet, ether_size, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_ADMIN);
 
 	via = (subnet->owner->via == myself) ? subnet->owner->nexthop : subnet->owner->via;
-	
+
 	if(via == source) {
 		logger(DEBUG_TRAFFIC, LOG_ERR, "Routing loop for packet from %s (%s)!", source->name, source->hostname);
 		return;
 	}
-	
+
 	if(directonly && subnet->owner != via)
-		return route_ipv6_unreachable(source, packet, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_ADMIN);
+		return route_ipv6_unreachable(source, packet, ether_size, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_ADMIN);
 
 	if(via && packet->len > MAX(via->mtu, 1294) && via != myself) {
 		logger(DEBUG_TRAFFIC, LOG_INFO, "Packet for %s (%s) length %d larger than MTU %d", subnet->owner->name, subnet->owner->hostname, packet->len, via->mtu);
 		packet->len = MAX(via->mtu, 1294);
-		route_ipv6_unreachable(source, packet, ICMP6_PACKET_TOO_BIG, 0);
+		route_ipv6_unreachable(source, packet, ether_size, ICMP6_PACKET_TOO_BIG, 0);
 		return;
 	}
 
 	clamp_mss(source, via, packet);
- 
+
 	send_packet(subnet->owner, packet);
 }
 
@@ -591,17 +594,17 @@ static void route_neighborsol(node_t *source, vpn_packet_t *packet) {
 	bool has_opt;
 
 	struct {
-		struct in6_addr ip6_src;	/* source address */
-		struct in6_addr ip6_dst;	/* destination address */
+		struct in6_addr ip6_src;
+		struct in6_addr ip6_dst;
 		uint32_t length;
 		uint32_t next;
 	} pseudo;
 
 	if(!checklength(source, packet, ether_size + ip6_size + ns_size))
 		return;
-	
+
 	has_opt = packet->len >= ether_size + ip6_size + ns_size + opt_size + ETH_ALEN;
-	
+
 	if(source != myself) {
 		logger(DEBUG_TRAFFIC, LOG_WARNING, "Got neighbor solicitation request from %s (%s) while in router mode!", source->name, source->hostname);
 		return;
@@ -672,22 +675,22 @@ static void route_neighborsol(node_t *source, vpn_packet_t *packet) {
 	/* Check if it is for our own subnet */
 
 	if(subnet->owner == myself)
-		return;					/* silently ignore */
+		return;                                          /* silently ignore */
 
 	/* Create neighbor advertation reply */
 
-	memcpy(packet->data, packet->data + ETH_ALEN, ETH_ALEN);	/* copy destination address */
-	packet->data[ETH_ALEN * 2 - 1] ^= 0xFF;	/* mangle source address so it looks like it's not from us */
+	memcpy(packet->data, packet->data + ETH_ALEN, ETH_ALEN); /* copy destination address */
+	packet->data[ETH_ALEN * 2 - 1] ^= 0xFF;                  /* mangle source address so it looks like it's not from us */
 
-	ip6.ip6_dst = ip6.ip6_src;			/* swap destination and source protocoll address */
+	ip6.ip6_dst = ip6.ip6_src;                               /* swap destination and source protocoll address */
 	ip6.ip6_src = ns.nd_ns_target;
 
 	if(has_opt)
-		memcpy(packet->data + ether_size + ip6_size + ns_size + opt_size, packet->data + ETH_ALEN, ETH_ALEN);	/* add fake source hard addr */
+		memcpy(packet->data + ether_size + ip6_size + ns_size + opt_size, packet->data + ETH_ALEN, ETH_ALEN);   /* add fake source hard addr */
 
 	ns.nd_ns_cksum = 0;
 	ns.nd_ns_type = ND_NEIGHBOR_ADVERT;
-	ns.nd_ns_reserved = htonl(0x40000000UL);	/* Set solicited flag */
+	ns.nd_ns_reserved = htonl(0x40000000UL);                 /* Set solicited flag */
 	opt.nd_opt_type = ND_OPT_TARGET_LINKADDR;
 
 	/* Create pseudo header */
@@ -782,17 +785,17 @@ static void route_arp(node_t *source, vpn_packet_t *packet) {
 	/* Check if it is for our own subnet */
 
 	if(subnet->owner == myself)
-		return;					/* silently ignore */
+		return;                                          /* silently ignore */
 
-	memcpy(packet->data, packet->data + ETH_ALEN, ETH_ALEN);	/* copy destination address */
-	packet->data[ETH_ALEN * 2 - 1] ^= 0xFF;	/* mangle source address so it looks like it's not from us */
+	memcpy(packet->data, packet->data + ETH_ALEN, ETH_ALEN); /* copy destination address */
+	packet->data[ETH_ALEN * 2 - 1] ^= 0xFF;                  /* mangle source address so it looks like it's not from us */
 
-	memcpy(&addr, arp.arp_tpa, sizeof addr);	/* save protocol addr */
-	memcpy(arp.arp_tpa, arp.arp_spa, sizeof addr);	/* swap destination and source protocol address */
-	memcpy(arp.arp_spa, &addr, sizeof addr);	/* ... */
+	memcpy(&addr, arp.arp_tpa, sizeof addr);                 /* save protocol addr */
+	memcpy(arp.arp_tpa, arp.arp_spa, sizeof addr);           /* swap destination and source protocol address */
+	memcpy(arp.arp_spa, &addr, sizeof addr);                 /* ... */
 
-	memcpy(arp.arp_tha, arp.arp_sha, ETH_ALEN);	/* set target hard/proto addr */
-	memcpy(arp.arp_sha, packet->data + ETH_ALEN, ETH_ALEN);	/* add fake source hard addr */
+	memcpy(arp.arp_tha, arp.arp_sha, ETH_ALEN);              /* set target hard/proto addr */
+	memcpy(arp.arp_sha, packet->data + ETH_ALEN, ETH_ALEN);  /* add fake source hard addr */
 	arp.arp_op = htons(ARPOP_REPLY);
 
 	/* Copy structs on stack back to packet */
@@ -838,27 +841,34 @@ static void route_mac(node_t *source, vpn_packet_t *packet) {
 
 	if(directonly && subnet->owner != via)
 		return;
-	
+
 	if(via && packet->len > via->mtu && via != myself) {
 		logger(DEBUG_TRAFFIC, LOG_INFO, "Packet for %s (%s) length %d larger than MTU %d", subnet->owner->name, subnet->owner->hostname, packet->len, via->mtu);
 		uint16_t type = packet->data[12] << 8 | packet->data[13];
-		if(type == ETH_P_IP && packet->len > 590) {
-			if(packet->data[20] & 0x40) {
+		length_t ethlen = 14;
+
+		if(type == ETH_P_8021Q) {
+			type = packet->data[16] << 8 | packet->data[17];
+			ethlen += 4;
+		}
+
+		if(type == ETH_P_IP && packet->len > 576 + ethlen) {
+			if(packet->data[6 + ethlen] & 0x40) {
 				packet->len = via->mtu;
-				route_ipv4_unreachable(source, packet, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED);
+				route_ipv4_unreachable(source, packet, ethlen, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED);
 			} else {
-				fragment_ipv4_packet(via, packet);
+				fragment_ipv4_packet(via, packet, ethlen);
 			}
 			return;
-		} else if(type == ETH_P_IPV6 && packet->len > 1294) {
+		} else if(type == ETH_P_IPV6 && packet->len > 1280 + ethlen) {
 			packet->len = via->mtu;
-			route_ipv6_unreachable(source, packet, ICMP6_PACKET_TOO_BIG, 0);
+			route_ipv6_unreachable(source, packet, ethlen, ICMP6_PACKET_TOO_BIG, 0);
 			return;
 		}
 	}
 
 	clamp_mss(source, via, packet);
- 
+
 	send_packet(subnet->owner, packet);
 }
 
@@ -881,42 +891,48 @@ static void send_pcap(vpn_packet_t *packet) {
 
 static bool do_decrement_ttl(node_t *source, vpn_packet_t *packet) {
 	uint16_t type = packet->data[12] << 8 | packet->data[13];
+	length_t ethlen = ether_size;
+
+	if(type == ETH_P_8021Q) {
+		type = packet->data[16] << 8 | packet->data[17];
+		ethlen += 4;
+	}
 
 	switch (type) {
 		case ETH_P_IP:
-			if(!checklength(source, packet, 14 + 32))
+			if(!checklength(source, packet, ethlen + ip_size))
 				return false;
 
-			if(packet->data[22] < 1) {
-				if(packet->data[25] != IPPROTO_ICMP || packet->data[46] != ICMP_TIME_EXCEEDED)
-					route_ipv4_unreachable(source, packet, ICMP_TIME_EXCEEDED, ICMP_EXC_TTL);
+			if(packet->data[ethlen + 8] < 1) {
+				if(packet->data[ethlen + 11] != IPPROTO_ICMP || packet->data[ethlen + 32] != ICMP_TIME_EXCEEDED)
+					route_ipv4_unreachable(source, packet, ethlen, ICMP_TIME_EXCEEDED, ICMP_EXC_TTL);
 				return false;
 			}
 
-			uint16_t old = packet->data[22] << 8 | packet->data[23];
-			packet->data[22]--;
-			uint16_t new = packet->data[22] << 8 | packet->data[23];
+			uint16_t old = packet->data[ethlen + 8] << 8 | packet->data[ethlen + 9];
+			packet->data[ethlen + 8]--;
+			uint16_t new = packet->data[ethlen + 8] << 8 | packet->data[ethlen + 9];
 
-			uint32_t checksum = packet->data[24] << 8 | packet->data[25];
+			uint32_t checksum = packet->data[ethlen + 10] << 8 | packet->data[ethlen + 11];
 			checksum += old + (~new & 0xFFFF);
 			while(checksum >> 16)
 				checksum = (checksum & 0xFFFF) + (checksum >> 16);
-			packet->data[24] = checksum >> 8;
-			packet->data[25] = checksum & 0xff;
+			packet->data[ethlen + 10] = checksum >> 8;
+			packet->data[ethlen + 11] = checksum & 0xff;
 
 			return true;
 
 		case ETH_P_IPV6:
-			if(!checklength(source, packet, 14 + 40))
+			if(!checklength(source, packet, ethlen + ip6_size))
 				return false;
 
-			if(packet->data[21] < 1) {
-				if(packet->data[20] != IPPROTO_ICMPV6 || packet->data[54] != ICMP6_TIME_EXCEEDED)
-					route_ipv6_unreachable(source, packet, ICMP6_TIME_EXCEEDED, ICMP6_TIME_EXCEED_TRANSIT);
+			if(packet->data[ethlen + 7] < 1) {
+				if(packet->data[ethlen + 6] != IPPROTO_ICMPV6 || packet->data[ethlen + 40] != ICMP6_TIME_EXCEEDED)
+					route_ipv6_unreachable(source, packet, ethlen, ICMP6_TIME_EXCEEDED, ICMP6_TIME_EXCEED_TRANSIT);
 				return false;
 			}
 
-			packet->data[21]--;
+			packet->data[ethlen + 7]--;
 
 			return true;
 
@@ -941,28 +957,26 @@ void route(node_t *source, vpn_packet_t *packet) {
 		if(!do_decrement_ttl(source, packet))
 			return;
 
+	uint16_t type = packet->data[12] << 8 | packet->data[13];
+
 	switch (routing_mode) {
 		case RMODE_ROUTER:
-			{
-				uint16_t type = packet->data[12] << 8 | packet->data[13];
-
-				switch (type) {
-					case ETH_P_ARP:
-						route_arp(source, packet);
-						break;
-
-					case ETH_P_IP:
-						route_ipv4(source, packet);
-						break;
-
-					case ETH_P_IPV6:
-						route_ipv6(source, packet);
-						break;
-
-					default:
-						logger(DEBUG_TRAFFIC, LOG_WARNING, "Cannot route packet from %s (%s): unknown type %hx", source->name, source->hostname, type);
-						break;
-				}
+			switch (type) {
+				case ETH_P_ARP:
+					route_arp(source, packet);
+					break;
+
+				case ETH_P_IP:
+					route_ipv4(source, packet);
+					break;
+
+				case ETH_P_IPV6:
+					route_ipv6(source, packet);
+					break;
+
+				default:
+					logger(DEBUG_TRAFFIC, LOG_WARNING, "Cannot route packet from %s (%s): unknown type %hx", source->name, source->hostname, type);
+					break;
 			}
 			break;