X-Git-Url: https://git.librecmc.org/?p=oweals%2Ftinc.git;a=blobdiff_plain;f=src%2Froute.c;h=50449897355ac97c28e1f24bf23adca247ec1023;hp=6c381ccf852b13159f105a733570159426654573;hb=07ace0b6481efcc0a058aab7b90b95edd31709da;hpb=3cb91d75f874e3398c35cd4280c1e0a1ceeedabc

diff --git a/src/route.c b/src/route.c
index 6c381cc..5044989 100644
--- a/src/route.c
+++ b/src/route.c
@@ -1,7 +1,8 @@
 /*
     route.c -- routing
     Copyright (C) 2000-2005 Ivo Timmermans,
-                  2000-2010 Guus Sliepen <guus@tinc-vpn.org>
+                  2000-2014 Guus Sliepen <guus@tinc-vpn.org>
+		  2015      Vittorio Gambaletta
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -33,6 +34,10 @@
 #include "utils.h"
 
 rmode_t routing_mode = RMODE_ROUTER;
+fmode_t forwarding_mode = FMODE_INTERNAL;
+bmode_t broadcast_mode = BMODE_MST;
+bool decrement_ttl = false;
+bool directonly = false;
 bool priorityinheritance = false;
 int macexpire = 600;
 bool overwrite_mac = false;
@@ -48,7 +53,10 @@ static const size_t ip6_size = sizeof(struct ip6_hdr);
 static const size_t icmp6_size = sizeof(struct icmp6_hdr);
 static const size_t ns_size = sizeof(struct nd_neighbor_solicit);
 static const size_t opt_size = sizeof(struct nd_opt_hdr);
-#define max(a, b) ((a) > (b) ? (a) : (b))
+
+#ifndef MAX
+#define MAX(a, b) ((a) > (b) ? (a) : (b))
+#endif
 
 /* RFC 1071 */
 
@@ -75,13 +83,14 @@ static bool ratelimit(int frequency) {
 	static int count = 0;
 	
 	if(lasttime == now) {
-		if(++count > frequency)
+		if(count >= frequency)
 			return true;
 	} else {
 		lasttime = now;
 		count = 0;
 	}
 
+	count++;
 	return false;
 }
 
@@ -93,6 +102,260 @@ static bool checklength(node_t *source, vpn_packet_t *packet, length_t length) {
 		return true;
 }
 
+static void swap_mac_addresses(vpn_packet_t *packet) {
+	mac_t tmp;
+	memcpy(&tmp, &packet->data[0], sizeof tmp);
+	memcpy(&packet->data[0], &packet->data[6], sizeof tmp);
+	memcpy(&packet->data[6], &tmp, sizeof tmp);
+}
+
+/* RFC 792 */
+
+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);
+
+	/* Copy headers from packet into properly aligned structs on the stack */
+
+	memcpy(&ip, packet->data + ether_size, ip_size);
+
+	/* Remember original source and destination */
+	
+	ip_src = ip.ip_src;
+	ip_dst = ip.ip_dst;
+
+	/* Try to reply with an IP address assigned to the local machine */
+
+	if (type == ICMP_TIME_EXCEEDED && code == ICMP_EXC_TTL) {
+		int sockfd = socket(AF_INET, SOCK_DGRAM, 0);
+		if (sockfd != -1) {
+			struct sockaddr_in addr;
+			memset(&addr, 0, sizeof(addr));
+			addr.sin_family = AF_INET;
+			addr.sin_addr = ip.ip_src;
+			if (!connect(sockfd, (const struct sockaddr*) &addr, sizeof(addr))) {
+				memset(&addr, 0, sizeof(addr));
+				addr.sin_family = AF_INET;
+				socklen_t addrlen = sizeof(addr);
+				if (!getsockname(sockfd, (struct sockaddr*) &addr, &addrlen) && addrlen <= sizeof(addr)) {
+					ip_dst = addr.sin_addr;
+				}
+			}
+			close(sockfd);
+		}
+	}
+
+	oldlen = packet->len - ether_size;
+
+	if(type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED)
+		icmp.icmp_nextmtu = htons(packet->len - ether_size);
+
+	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;
+	ip.ip_len = htons(ip_size + icmp_size + oldlen);
+	ip.ip_id = 0;
+	ip.ip_off = 0;
+	ip.ip_ttl = 255;
+	ip.ip_p = IPPROTO_ICMP;
+	ip.ip_sum = 0;
+	ip.ip_src = ip_dst;
+	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);
+
+	/* Copy structs on stack back to packet */
+
+	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);
+}
+
+/* RFC 2463 */
+
+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;	
+
+	struct {
+		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);
+
+	/* Copy headers from packet to structs on the stack */
+
+	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;
+
+	/* Try to reply with an IP address assigned to the local machine */
+
+	if (type == ICMP6_TIME_EXCEEDED && code == ICMP6_TIME_EXCEED_TRANSIT) {
+		int sockfd = socket(AF_INET6, SOCK_DGRAM, 0);
+		if (sockfd != -1) {
+			struct sockaddr_in6 addr;
+			memset(&addr, 0, sizeof(addr));
+			addr.sin6_family = AF_INET6;
+			addr.sin6_addr = ip6.ip6_src;
+			if (!connect(sockfd, (const struct sockaddr*) &addr, sizeof(addr))) {
+				memset(&addr, 0, sizeof(addr));
+				addr.sin6_family = AF_INET6;
+				socklen_t addrlen = sizeof(addr);
+				if (!getsockname(sockfd, (struct sockaddr*) &addr, &addrlen) && addrlen <= sizeof(addr)) {
+					pseudo.ip6_src = addr.sin6_addr;
+				}
+			}
+			close(sockfd);
+		}
+	}
+
+	pseudo.length = packet->len - ether_size;
+
+	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;
+	ip6.ip6_hlim = 255;
+	ip6.ip6_src = pseudo.ip6_src;
+	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);
+
+	icmp6.icmp6_cksum = checksum;
+
+	/* Copy structs on stack back to packet */
+
+	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);
+}
+
+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, ethlen + ip_size))
+				return false;
+
+			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[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[ethlen + 10] << 8 | packet->data[ethlen + 11];
+			checksum += old + (~new & 0xFFFF);
+			while(checksum >> 16)
+				checksum = (checksum & 0xFFFF) + (checksum >> 16);
+			packet->data[ethlen + 10] = checksum >> 8;
+			packet->data[ethlen + 11] = checksum & 0xff;
+
+			return true;
+
+		case ETH_P_IPV6:
+			if(!checklength(source, packet, ethlen + ip6_size))
+				return false;
+
+			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[ethlen + 7]--;
+
+			return true;
+
+		default:
+			return true;
+	}
+}
+
 static void clamp_mss(const node_t *source, const node_t *via, vpn_packet_t *packet) {
 	if(!source || !via || !(via->options & OPTION_CLAMP_MSS))
 		return;
@@ -102,15 +365,22 @@ 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(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(!start || packet->len <= start + 20)
+	if(packet->len <= start + 20)
 		return;
 
 	/* Use data offset field to calculate length of options field */
@@ -145,7 +415,7 @@ static void clamp_mss(const node_t *source, const node_t *via, vpn_packet_t *pac
 		/* Found it */
 		uint16_t oldmss = packet->data[start + 22 + i] << 8 | packet->data[start + 23 + i];
 		uint16_t newmss = mtu - start - 20;
-		uint16_t csum = packet->data[start + 16] << 8 | packet->data[start + 17];
+		uint32_t csum = packet->data[start + 16] << 8 | packet->data[start + 17];
 
 		if(oldmss <= newmss)
 			break;
@@ -156,21 +426,16 @@ static void clamp_mss(const node_t *source, const node_t *via, vpn_packet_t *pac
 		packet->data[start + 22 + i] = newmss >> 8;
 		packet->data[start + 23 + i] = newmss & 0xff;
 		csum ^= 0xffff;
-		csum -= oldmss;
+		csum += oldmss ^ 0xffff;
 		csum += newmss;
+		csum = (csum & 0xffff) + (csum >> 16);
+		csum += csum >> 16;
 		csum ^= 0xffff;
 		packet->data[start + 16] = csum >> 8;
-		packet->data[start + 17] = csum & 0xff;
+		packet->data[start + 17] = csum;
 		break;
 	}
 }
-
-static void swap_mac_addresses(vpn_packet_t *packet) {
-	mac_t tmp;
-	memcpy(&tmp, &packet->data[0], sizeof tmp);
-	memcpy(&packet->data[0], &packet->data[6], sizeof tmp);
-	memcpy(&packet->data[6], &tmp, sizeof tmp);
-}
 	
 static void learn_mac(mac_t *address) {
 	subnet_t *subnet;
@@ -182,7 +447,7 @@ static void learn_mac(mac_t *address) {
 	/* If we don't know this MAC address yet, store it */
 
 	if(!subnet) {
-		ifdebug(TRAFFIC) logger(LOG_INFO, "Learned new MAC address %hx:%hx:%hx:%hx:%hx:%hx",
+		ifdebug(TRAFFIC) logger(LOG_INFO, "Learned new MAC address %x:%x:%x:%x:%x:%x",
 				   address->x[0], address->x[1], address->x[2], address->x[3],
 				   address->x[4], address->x[5]);
 
@@ -215,7 +480,7 @@ void age_subnets(void) {
 	for(node = myself->subnet_tree->head; node; node = next) {
 		next = node->next;
 		s = node->data;
-		if(s->expires && s->expires < now) {
+		if(s->expires && s->expires <= now) {
 			ifdebug(TRAFFIC) {
 				char netstr[MAXNETSTR];
 				if(net2str(netstr, sizeof netstr, s))
@@ -234,82 +499,17 @@ void age_subnets(void) {
 	}
 }
 
-/* RFC 792 */
-
-static void route_ipv4_unreachable(node_t *source, vpn_packet_t *packet, 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);
-
-	/* Copy headers from packet into properly aligned structs on the stack */
-
-	memcpy(&ip, packet->data + ether_size, ip_size);
-
-	/* Remember original source and destination */
-	
-	ip_src = ip.ip_src;
-	ip_dst = ip.ip_dst;
-
-	oldlen = packet->len - ether_size;
-
-	if(type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED)
-		icmp.icmp_nextmtu = htons(packet->len - ether_size);
-
-	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;
-	ip.ip_len = htons(ip_size + icmp_size + oldlen);
-	ip.ip_id = 0;
-	ip.ip_off = 0;
-	ip.ip_ttl = 255;
-	ip.ip_p = IPPROTO_ICMP;
-	ip.ip_sum = 0;
-	ip.ip_src = ip_dst;
-	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);
-
-	/* Copy structs on stack back to packet */
-
-	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;
+static void route_broadcast(node_t *source, vpn_packet_t *packet) {
+	if(decrement_ttl && source != myself)
+		if(!do_decrement_ttl(source, packet))
+			return;
 
-	send_packet(source, packet);
+	broadcast_packet(source, packet);
 }
 
 /* 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;
@@ -325,7 +525,7 @@ static void fragment_ipv4_packet(node_t *dest, vpn_packet_t *packet) {
 	todo = ntohs(ip.ip_len) - ip_size;
 
 	if(ether_size + ip_size + todo != packet->len) {
-		ifdebug(TRAFFIC) logger(LOG_WARNING, "Length of packet (%d) doesn't match length in IPv4 header (%zd)", packet->len, ether_size + ip_size + todo);
+		ifdebug(TRAFFIC) logger(LOG_WARNING, "Length of packet (%d) doesn't match length in IPv4 header (%d)", packet->len, (int)(ether_size + ip_size + todo));
 		return;
 	}
 
@@ -373,7 +573,7 @@ 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;
 	}
 	
@@ -383,20 +583,35 @@ static void route_ipv4_unicast(node_t *source, vpn_packet_t *packet) {
 	}
 
 	if(!subnet->owner->status.reachable)
-		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, ether_size, ICMP_DEST_UNREACH, ICMP_NET_ANO);
+
+	if(decrement_ttl && source != myself && subnet->owner != myself)
+		if(!do_decrement_ttl(source, packet))
+			return;
 
 	if(priorityinheritance)
 		packet->priority = packet->data[15];
 
 	via = (subnet->owner->via == myself) ? subnet->owner->nexthop : subnet->owner->via;
+
+	if(via == source) {
+		ifdebug(TRAFFIC) logger(LOG_ERR, "Routing loop for packet from %s (%s)!", source->name, source->hostname);
+		return;
+	}
 	
-	if(via && packet->len > max(via->mtu, 590) && via != myself) {
+	if(directonly && subnet->owner != via)
+		return route_ipv4_unreachable(source, packet, ether_size, ICMP_DEST_UNREACH, ICMP_NET_ANO);
+
+	if(via && packet->len > MAX(via->mtu, 590) && via != myself) {
 		ifdebug(TRAFFIC) logger(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);
+			packet->len = MAX(via->mtu, 590);
+			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;
@@ -411,96 +626,16 @@ static void route_ipv4(node_t *source, vpn_packet_t *packet) {
 	if(!checklength(source, packet, ether_size + ip_size))
 		return;
 
-	if(((packet->data[30] & 0xf0) == 0xe0) || (
+	if(broadcast_mode && (((packet->data[30] & 0xf0) == 0xe0) || (
 			packet->data[30] == 255 &&
 			packet->data[31] == 255 &&
 			packet->data[32] == 255 &&
-			packet->data[33] == 255))
-		broadcast_packet(source, packet);
+			packet->data[33] == 255)))
+		route_broadcast(source, packet);
 	else
 		route_ipv4_unicast(source, packet);
 }
 
-/* RFC 2463 */
-
-static void route_ipv6_unreachable(node_t *source, vpn_packet_t *packet, uint8_t type, uint8_t code) {
-	struct ip6_hdr ip6;
-	struct icmp6_hdr icmp6 = {0};
-	uint16_t checksum;	
-
-	struct {
-		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);
-
-	/* Copy headers from packet to structs on the stack */
-
-	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;
-
-	pseudo.length = packet->len - ether_size;
-
-	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;
-	ip6.ip6_hlim = 255;
-	ip6.ip6_src = pseudo.ip6_src;
-	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);
-
-	icmp6.icmp6_cksum = checksum;
-
-	/* Copy structs on stack back to packet */
-
-	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);
-}
-
 static void route_ipv6_unicast(node_t *source, vpn_packet_t *packet) {
 	subnet_t *subnet;
 	node_t *via;
@@ -521,7 +656,7 @@ 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;
 	}
 
@@ -531,14 +666,32 @@ static void route_ipv6_unicast(node_t *source, vpn_packet_t *packet) {
 	}
 
 	if(!subnet->owner->status.reachable)
-		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, ether_size, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_ADMIN);
+
+	if(decrement_ttl && source != myself && subnet->owner != myself)
+		if(!do_decrement_ttl(source, packet))
+			return;
+
+	if(priorityinheritance)
+		packet->priority = ((packet->data[14] & 0x0f) << 4) | (packet->data[15] >> 4);
 
 	via = (subnet->owner->via == myself) ? subnet->owner->nexthop : subnet->owner->via;
 	
-	if(via && packet->len > max(via->mtu, 1294) && via != myself) {
+	if(via == source) {
+		ifdebug(TRAFFIC) logger(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, ether_size, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_ADMIN);
+
+	if(via && packet->len > MAX(via->mtu, 1294) && via != myself) {
 		ifdebug(TRAFFIC) logger(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);
+		packet->len = MAX(via->mtu, 1294);
+		route_ipv6_unreachable(source, packet, ether_size, ICMP6_PACKET_TOO_BIG, 0);
 		return;
 	}
 
@@ -641,6 +794,10 @@ static void route_neighborsol(node_t *source, vpn_packet_t *packet) {
 	if(subnet->owner == myself)
 		return;					/* silently ignore */
 
+	if(decrement_ttl)
+		if(!do_decrement_ttl(source, packet))
+			return;
+
 	/* Create neighbor advertation reply */
 
 	memcpy(packet->data, packet->data + ETH_ALEN, ETH_ALEN);	/* copy destination address */
@@ -697,8 +854,8 @@ static void route_ipv6(node_t *source, vpn_packet_t *packet) {
 		return;
 	}
 
-	if(packet->data[38] == 255)
-		broadcast_packet(source, packet);
+	if(broadcast_mode && packet->data[38] == 255)
+		route_broadcast(source, packet);
 	else
 		route_ipv6_unicast(source, packet);
 }
@@ -751,6 +908,10 @@ static void route_arp(node_t *source, vpn_packet_t *packet) {
 	if(subnet->owner == myself)
 		return;					/* silently ignore */
 
+	if(decrement_ttl)
+		if(!do_decrement_ttl(source, packet))
+			return;
+
 	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 */
 
@@ -787,7 +948,7 @@ static void route_mac(node_t *source, vpn_packet_t *packet) {
 	subnet = lookup_subnet_mac(NULL, &dest);
 
 	if(!subnet) {
-		broadcast_packet(source, packet);
+		route_broadcast(source, packet);
 		return;
 	}
 
@@ -796,24 +957,49 @@ static void route_mac(node_t *source, vpn_packet_t *packet) {
 		return;
 	}
 
+	if(forwarding_mode == FMODE_OFF && source != myself && subnet->owner != myself)
+		return;
+
+	if(decrement_ttl && source != myself && subnet->owner != myself)
+		if(!do_decrement_ttl(source, packet))
+			return;
+
+	uint16_t type = packet->data[12] << 8 | packet->data[13];
+
+	if(priorityinheritance) {
+		if(type == ETH_P_IP && packet->len >= ether_size + ip_size)
+			packet->priority = packet->data[15];
+		else if(type == ETH_P_IPV6 && packet->len >= ether_size + ip6_size)
+			packet->priority = ((packet->data[14] & 0x0f) << 4) | (packet->data[15] >> 4);
+	}
+
 	// Handle packets larger than PMTU
 
 	node_t *via = (subnet->owner->via == myself) ? subnet->owner->nexthop : subnet->owner->via;
+
+	if(directonly && subnet->owner != via)
+		return;
 	
 	if(via && packet->len > via->mtu && via != myself) {
 		ifdebug(TRAFFIC) logger(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;
 		}
 	}
@@ -824,6 +1010,11 @@ static void route_mac(node_t *source, vpn_packet_t *packet) {
 }
 
 void route(node_t *source, vpn_packet_t *packet) {
+	if(forwarding_mode == FMODE_KERNEL && source != myself) {
+		send_packet(myself, packet);
+		return;
+	}
+
 	if(!checklength(source, packet, ether_size))
 		return;
 
@@ -857,7 +1048,7 @@ void route(node_t *source, vpn_packet_t *packet) {
 			break;
 
 		case RMODE_HUB:
-			broadcast_packet(source, packet);
+			route_broadcast(source, packet);
 			break;
 	}
 }