X-Git-Url: https://www.tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Froute.c;h=e3bcf3bb09ffc302cc135167212c18019fa1abdd;hp=7538bec517c8a70a42bf6d566d63448e8d6f5d44;hb=708314df2f61675d0f54e541c9fff62ac1f433b5;hpb=a227843b739d279b63adcf3736ebb03d856080c4

diff --git a/src/route.c b/src/route.c
index 7538bec5..e3bcf3bb 100644
--- a/src/route.c
+++ b/src/route.c
@@ -1,7 +1,7 @@
 /*
     route.c -- routing
     Copyright (C) 2000-2005 Ivo Timmermans,
-                  2000-2009 Guus Sliepen <guus@tinc-vpn.org>
+                  2000-2010 Guus Sliepen <guus@tinc-vpn.org>
 
     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 +33,8 @@
 #include "utils.h"
 
 rmode_t routing_mode = RMODE_ROUTER;
+fmode_t forwarding_mode = FMODE_INTERNAL;
+bool directonly = false;
 bool priorityinheritance = false;
 int macexpire = 600;
 bool overwrite_mac = false;
@@ -49,6 +51,10 @@ 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);
 
+#ifndef MAX
+#define MAX(a, b) ((a) > (b) ? (a) : (b))
+#endif
+
 /* RFC 1071 */
 
 static uint16_t inet_checksum(void *data, int len, uint16_t prevsum) {
@@ -86,12 +92,84 @@ static bool ratelimit(int frequency) {
 
 static bool checklength(node_t *source, vpn_packet_t *packet, length_t length) {
 	if(packet->len < length) {
-		ifdebug(TRAFFIC) logger(LOG_WARNING, _("Got too short packet from %s (%s)"), source->name, source->hostname);
+		ifdebug(TRAFFIC) logger(LOG_WARNING, "Got too short packet from %s (%s)", source->name, source->hostname);
 		return false;
 	} else
 		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;
+
+	uint16_t mtu = source->mtu;
+	if(via != myself && via->mtu < mtu)
+		mtu = via->mtu;
+
+	/* Find TCP header */
+	int start = 0;
+	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(!start || packet->len <= start + 20)
+		return;
+
+	/* Use data offset field to calculate length of options field */
+	int len = ((packet->data[start + 12] >> 4) - 5) * 4;
+
+	if(packet->len < start + 20 + len)
+		return;
+
+	/* Search for MSS option header */
+	for(int i = 0; i < len;) {
+		if(packet->data[start + 20 + i] == 0)
+			break;
+
+		if(packet->data[start + 20 + i] == 1) {
+			i++;
+			continue;
+		}
+
+		if(i > len - 2 || i > len - packet->data[start + 21 + i])
+			break;
+
+		if(packet->data[start + 20 + i] != 2) {
+			if(packet->data[start + 21 + i] < 2)
+				break;
+			i += packet->data[start + 21 + i];
+			continue;
+		}
+
+		if(packet->data[start + 21] != 4)
+			break;
+
+		/* 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];
+
+		if(oldmss <= newmss)
+			break;
+		
+		ifdebug(TRAFFIC) logger(LOG_INFO, "Clamping MSS of packet from %s to %s to %d", source->name, via->name, newmss);
+
+		/* Update the MSS value and the checksum */
+		packet->data[start + 22 + i] = newmss >> 8;
+		packet->data[start + 23 + i] = newmss & 0xff;
+		csum ^= 0xffff;
+		csum -= oldmss;
+		csum += newmss;
+		csum ^= 0xffff;
+		packet->data[start + 16] = csum >> 8;
+		packet->data[start + 17] = csum & 0xff;
+		break;
+	}
+}
+
 static void swap_mac_addresses(vpn_packet_t *packet) {
 	mac_t tmp;
 	memcpy(&tmp, &packet->data[0], sizeof tmp);
@@ -104,12 +182,12 @@ static void learn_mac(mac_t *address) {
 	avl_node_t *node;
 	connection_t *c;
 
-	subnet = lookup_subnet_mac(address);
+	subnet = lookup_subnet_mac(myself, 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 %hx:%hx:%hx:%hx:%hx:%hx",
 				   address->x[0], address->x[1], address->x[2], address->x[3],
 				   address->x[4], address->x[5]);
 
@@ -117,7 +195,9 @@ static void learn_mac(mac_t *address) {
 		subnet->type = SUBNET_MAC;
 		subnet->expires = now + macexpire;
 		subnet->net.mac.address = *address;
+		subnet->weight = 10;
 		subnet_add(myself, subnet);
+		subnet_update(myself, subnet, true);
 
 		/* And tell all other tinc daemons it's our MAC */
 
@@ -140,11 +220,11 @@ 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))
-					logger(LOG_INFO, _("Subnet %s expired"), netstr);
+					logger(LOG_INFO, "Subnet %s expired", netstr);
 			}
 
 			for(node2 = connection_tree->head; node2; node2 = node2->next) {
@@ -153,6 +233,7 @@ void age_subnets(void) {
 					send_del_subnet(c, s);
 			}
 
+			subnet_update(myself, s, false);
 			subnet_del(myself, s);
 		}
 	}
@@ -249,11 +330,11 @@ 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 (%zd)", packet->len, ether_size + ip_size + todo);
 		return;
 	}
 
-	ifdebug(TRAFFIC) logger(LOG_INFO, _("Fragmenting packet of %d bytes to %s (%s)"), packet->len, dest->name, dest->hostname);
+	ifdebug(TRAFFIC) logger(LOG_INFO, "Fragmenting packet of %d bytes to %s (%s)", packet->len, dest->name, dest->hostname);
 
 	offset = packet->data + ether_size + ip_size;
 	maxlen = (dest->mtu - ether_size - ip_size) & ~0x7;
@@ -290,7 +371,7 @@ static void route_ipv4_unicast(node_t *source, vpn_packet_t *packet) {
 	subnet = lookup_subnet_ipv4(&dest);
 
 	if(!subnet) {
-		ifdebug(TRAFFIC) logger(LOG_WARNING, _("Cannot route packet from %s (%s): unknown IPv4 destination address %d.%d.%d.%d"),
+		ifdebug(TRAFFIC) logger(LOG_WARNING, "Cannot route packet from %s (%s): unknown IPv4 destination address %d.%d.%d.%d",
 				source->name, source->hostname,
 				dest.x[0],
 				dest.x[1],
@@ -302,22 +383,28 @@ static void route_ipv4_unicast(node_t *source, vpn_packet_t *packet) {
 	}
 	
 	if(subnet->owner == source) {
-		ifdebug(TRAFFIC) logger(LOG_WARNING, _("Packet looping back to %s (%s)!"), source->name, source->hostname);
+		ifdebug(TRAFFIC) logger(LOG_WARNING, "Packet looping back to %s (%s)!", source->name, source->hostname);
 		return;
 	}
 
 	if(!subnet->owner->status.reachable)
-		route_ipv4_unreachable(source, packet, ICMP_DEST_UNREACH, ICMP_NET_UNREACH);
+		return route_ipv4_unreachable(source, packet, 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);
 
 	if(priorityinheritance)
 		packet->priority = packet->data[15];
 
 	via = (subnet->owner->via == myself) ? subnet->owner->nexthop : subnet->owner->via;
 	
-	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);
+	if(directonly && subnet->owner != via)
+		return route_ipv4_unreachable(source, packet, 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 = via->mtu;
+			packet->len = MAX(via->mtu, 590);
 			route_ipv4_unreachable(source, packet, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED);
 		} else {
 			fragment_ipv4_packet(via, packet);
@@ -326,6 +413,8 @@ static void route_ipv4_unicast(node_t *source, vpn_packet_t *packet) {
 		return;
 	}
 
+	clamp_mss(source, via, packet);
+ 
 	send_packet(subnet->owner, packet);
 }
 
@@ -432,7 +521,7 @@ static void route_ipv6_unicast(node_t *source, vpn_packet_t *packet) {
 	subnet = lookup_subnet_ipv6(&dest);
 
 	if(!subnet) {
-		ifdebug(TRAFFIC) logger(LOG_WARNING, _("Cannot route packet from %s (%s): unknown IPv6 destination address %hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx"),
+		ifdebug(TRAFFIC) logger(LOG_WARNING, "Cannot route packet from %s (%s): unknown IPv6 destination address %hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx",
 				source->name, source->hostname,
 				ntohs(dest.x[0]),
 				ntohs(dest.x[1]),
@@ -448,22 +537,30 @@ static void route_ipv6_unicast(node_t *source, vpn_packet_t *packet) {
 	}
 
 	if(subnet->owner == source) {
-		ifdebug(TRAFFIC) logger(LOG_WARNING, _("Packet looping back to %s (%s)!"), source->name, source->hostname);
+		ifdebug(TRAFFIC) logger(LOG_WARNING, "Packet looping back to %s (%s)!", source->name, source->hostname);
 		return;
 	}
 
 	if(!subnet->owner->status.reachable)
-		route_ipv6_unreachable(source, packet, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOROUTE);
+		return route_ipv6_unreachable(source, packet, 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);
 
 	via = (subnet->owner->via == myself) ? subnet->owner->nexthop : subnet->owner->via;
 	
-	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);
-		packet->len = via->mtu;
+	if(directonly && subnet->owner != via)
+		return route_ipv6_unreachable(source, packet, 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);
 		return;
 	}
 
+	clamp_mss(source, via, packet);
+ 
 	send_packet(subnet->owner, packet);
 }
 
@@ -490,7 +587,7 @@ static void route_neighborsol(node_t *source, vpn_packet_t *packet) {
 	has_opt = packet->len >= ether_size + ip6_size + ns_size + opt_size + ETH_ALEN;
 	
 	if(source != myself) {
-		ifdebug(TRAFFIC) logger(LOG_WARNING, _("Got neighbor solicitation request from %s (%s) while in router mode!"), source->name, source->hostname);
+		ifdebug(TRAFFIC) logger(LOG_WARNING, "Got neighbor solicitation request from %s (%s) while in router mode!", source->name, source->hostname);
 		return;
 	}
 
@@ -510,7 +607,7 @@ static void route_neighborsol(node_t *source, vpn_packet_t *packet) {
 
 	if(ns.nd_ns_hdr.icmp6_type != ND_NEIGHBOR_SOLICIT ||
 	   (has_opt && opt.nd_opt_type != ND_OPT_SOURCE_LINKADDR)) {
-		ifdebug(TRAFFIC) logger(LOG_WARNING, _("Cannot route packet: received unknown type neighbor solicitation request"));
+		ifdebug(TRAFFIC) logger(LOG_WARNING, "Cannot route packet: received unknown type neighbor solicitation request");
 		return;
 	}
 
@@ -534,7 +631,7 @@ static void route_neighborsol(node_t *source, vpn_packet_t *packet) {
 	}
 
 	if(checksum) {
-		ifdebug(TRAFFIC) logger(LOG_WARNING, _("Cannot route packet: checksum error for neighbor solicitation request"));
+		ifdebug(TRAFFIC) logger(LOG_WARNING, "Cannot route packet: checksum error for neighbor solicitation request");
 		return;
 	}
 
@@ -543,7 +640,7 @@ static void route_neighborsol(node_t *source, vpn_packet_t *packet) {
 	subnet = lookup_subnet_ipv6((ipv6_t *) &ns.nd_ns_target);
 
 	if(!subnet) {
-		ifdebug(TRAFFIC) logger(LOG_WARNING, _("Cannot route packet: neighbor solicitation request for unknown address %hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx"),
+		ifdebug(TRAFFIC) logger(LOG_WARNING, "Cannot route packet: neighbor solicitation request for unknown address %hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx",
 				   ntohs(((uint16_t *) &ns.nd_ns_target)[0]),
 				   ntohs(((uint16_t *) &ns.nd_ns_target)[1]),
 				   ntohs(((uint16_t *) &ns.nd_ns_target)[2]),
@@ -634,7 +731,7 @@ static void route_arp(node_t *source, vpn_packet_t *packet) {
 		return;
 
 	if(source != myself) {
-		ifdebug(TRAFFIC) logger(LOG_WARNING, _("Got ARP request from %s (%s) while in router mode!"), source->name, source->hostname);
+		ifdebug(TRAFFIC) logger(LOG_WARNING, "Got ARP request from %s (%s) while in router mode!", source->name, source->hostname);
 		return;
 	}
 
@@ -651,7 +748,7 @@ static void route_arp(node_t *source, vpn_packet_t *packet) {
 
 	if(ntohs(arp.arp_hrd) != ARPHRD_ETHER || ntohs(arp.arp_pro) != ETH_P_IP ||
 	   arp.arp_hln != ETH_ALEN || arp.arp_pln != sizeof(addr) || ntohs(arp.arp_op) != ARPOP_REQUEST) {
-		ifdebug(TRAFFIC) logger(LOG_WARNING, _("Cannot route packet: received unknown type ARP request"));
+		ifdebug(TRAFFIC) logger(LOG_WARNING, "Cannot route packet: received unknown type ARP request");
 		return;
 	}
 
@@ -660,7 +757,7 @@ static void route_arp(node_t *source, vpn_packet_t *packet) {
 	subnet = lookup_subnet_ipv4((ipv4_t *) &arp.arp_tpa);
 
 	if(!subnet) {
-		ifdebug(TRAFFIC) logger(LOG_WARNING, _("Cannot route packet: ARP request for unknown address %d.%d.%d.%d"),
+		ifdebug(TRAFFIC) logger(LOG_WARNING, "Cannot route packet: ARP request for unknown address %d.%d.%d.%d",
 				   arp.arp_tpa[0], arp.arp_tpa[1], arp.arp_tpa[2],
 				   arp.arp_tpa[3]);
 		return;
@@ -704,7 +801,7 @@ static void route_mac(node_t *source, vpn_packet_t *packet) {
 	/* Lookup destination address */
 
 	memcpy(&dest, &packet->data[0], sizeof dest);
-	subnet = lookup_subnet_mac(&dest);
+	subnet = lookup_subnet_mac(NULL, &dest);
 
 	if(!subnet) {
 		broadcast_packet(source, packet);
@@ -712,18 +809,24 @@ static void route_mac(node_t *source, vpn_packet_t *packet) {
 	}
 
 	if(subnet->owner == source) {
-		ifdebug(TRAFFIC) logger(LOG_WARNING, _("Packet looping back to %s (%s)!"), source->name, source->hostname);
+		ifdebug(TRAFFIC) logger(LOG_WARNING, "Packet looping back to %s (%s)!", source->name, source->hostname);
 		return;
 	}
 
+	if(forwarding_mode == FMODE_OFF && source != myself && subnet->owner != myself)
+		return;
+
 	// 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);
+		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) {
+		if(type == ETH_P_IP && packet->len > 590) {
 			if(packet->data[20] & 0x40) {
 				packet->len = via->mtu;
 				route_ipv4_unreachable(source, packet, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED);
@@ -731,17 +834,24 @@ static void route_mac(node_t *source, vpn_packet_t *packet) {
 				fragment_ipv4_packet(via, packet);
 			}
 			return;
-		} else if(type == ETH_P_IPV6) {
+		} else if(type == ETH_P_IPV6 && packet->len > 1294) {
 			packet->len = via->mtu;
 			route_ipv6_unreachable(source, packet, ICMP6_PACKET_TOO_BIG, 0);
 			return;
 		}
 	}
 
+	clamp_mss(source, via, packet);
+ 
 	send_packet(subnet->owner, 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;
 
@@ -764,7 +874,7 @@ void route(node_t *source, vpn_packet_t *packet) {
 						break;
 
 					default:
-						ifdebug(TRAFFIC) logger(LOG_WARNING, _("Cannot route packet from %s (%s): unknown type %hx"), source->name, source->hostname, type);
+						ifdebug(TRAFFIC) logger(LOG_WARNING, "Cannot route packet from %s (%s): unknown type %hx", source->name, source->hostname, type);
 						break;
 				}
 			}