/*
route.c -- routing
Copyright (C) 2000-2005 Ivo Timmermans,
- 2000-2009 Guus Sliepen <guus@tinc-vpn.org>
+ 2000-2014 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
#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;
static const size_t ns_size = sizeof(struct nd_neighbor_solicit);
static const size_t opt_size = sizeof(struct nd_opt_hdr);
+static bool do_decrement_ttl(node_t *source, vpn_packet_t *packet);
+
+#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)
-{
+static uint16_t inet_checksum(void *data, int len, uint16_t prevsum) {
uint16_t *p = data;
uint32_t checksum = prevsum ^ 0xFFFF;
static int count = 0;
if(lasttime == now) {
- if(++count > frequency)
+ if(count >= frequency)
return true;
} else {
lasttime = now;
count = 0;
}
+ count++;
return false;
}
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 = ether_size;
+ uint16_t type = packet->data[12] << 8 | packet->data[13];
+
+ 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(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;
+ uint32_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 ^ 0xffff;
+ csum += newmss;
+ csum = (csum & 0xffff) + (csum >> 16);
+ csum += csum >> 16;
+ csum ^= 0xffff;
+ packet->data[start + 16] = csum >> 8;
+ 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[6], &tmp, sizeof tmp);
}
-static void learn_mac(mac_t *address)
-{
+static void learn_mac(mac_t *address) {
subnet_t *subnet;
avl_node_t *node;
connection_t *c;
- cp();
-
- 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 %x:%x:%x:%x:%x:%x",
address->x[0], address->x[1], address->x[2], address->x[3],
address->x[4], address->x[5]);
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 */
subnet->expires = now + macexpire;
}
-void age_subnets(void)
-{
+void age_subnets(void) {
subnet_t *s;
connection_t *c;
avl_node_t *node, *next, *node2;
- cp();
-
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) {
send_del_subnet(c, s);
}
+ subnet_update(myself, s, false);
subnet_del(myself, s);
}
}
}
+static void broadcast_packet_helper(node_t *source, vpn_packet_t *packet) {
+ if(decrement_ttl && source != myself)
+ if(!do_decrement_ttl(source, packet))
+ return;
+
+ broadcast_packet(source, packet);
+}
+
/* 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};
if(ratelimit(3))
return;
- cp();
-
/* Swap Ethernet source and destination addresses */
swap_mac_addresses(packet);
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)
/* 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;
- cp();
-
memcpy(&ip, packet->data + ether_size, ip_size);
fragment.priority = packet->priority;
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;
}
- 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;
}
}
-static void route_ipv4_unicast(node_t *source, vpn_packet_t *packet)
-{
+static void route_ipv4_unicast(node_t *source, vpn_packet_t *packet) {
subnet_t *subnet;
node_t *via;
ipv4_t dest;
- cp();
-
memcpy(&dest, &packet->data[30], sizeof dest);
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],
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) {
- 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, 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 > 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, 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 = via->mtu;
- 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;
}
+ clamp_mss(source, via, packet);
+
send_packet(subnet->owner, packet);
}
-static void route_ipv4(node_t *source, vpn_packet_t *packet)
-{
- cp();
-
+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)))
+ broadcast_packet_helper(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)
-{
+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;
if(ratelimit(3))
return;
- cp();
-
/* Swap Ethernet source and destination addresses */
swap_mac_addresses(packet);
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)
send_packet(source, packet);
}
-static void route_ipv6_unicast(node_t *source, vpn_packet_t *packet)
-{
+static void route_ipv6_unicast(node_t *source, vpn_packet_t *packet) {
subnet_t *subnet;
node_t *via;
ipv6_t dest;
- cp();
-
memcpy(&dest, &packet->data[38], sizeof dest);
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]),
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;
}
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, 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;
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;
- route_ipv6_unreachable(source, packet, ICMP6_PACKET_TOO_BIG, 0);
+ 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, ether_size, ICMP6_PACKET_TOO_BIG, 0);
return;
}
+ clamp_mss(source, via, packet);
+
send_packet(subnet->owner, packet);
}
/* RFC 2461 */
-static void route_neighborsol(node_t *source, vpn_packet_t *packet)
-{
+static void route_neighborsol(node_t *source, vpn_packet_t *packet) {
struct ip6_hdr ip6;
struct nd_neighbor_solicit ns;
struct nd_opt_hdr opt;
uint32_t next;
} pseudo;
- cp();
-
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) {
- 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;
}
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;
}
}
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;
}
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]),
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 */
send_packet(source, packet);
}
-static void route_ipv6(node_t *source, vpn_packet_t *packet)
-{
- cp();
-
+static void route_ipv6(node_t *source, vpn_packet_t *packet) {
if(!checklength(source, packet, ether_size + ip6_size))
return;
return;
}
- if(packet->data[38] == 255)
- broadcast_packet(source, packet);
+ if(broadcast_mode && packet->data[38] == 255)
+ broadcast_packet_helper(source, packet);
else
route_ipv6_unicast(source, packet);
}
/* RFC 826 */
-static void route_arp(node_t *source, vpn_packet_t *packet)
-{
+static void route_arp(node_t *source, vpn_packet_t *packet) {
struct ether_arp arp;
subnet_t *subnet;
struct in_addr addr;
- cp();
-
if(!checklength(source, packet, ether_size + arp_size))
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;
}
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;
}
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;
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 */
send_packet(source, packet);
}
-static void route_mac(node_t *source, vpn_packet_t *packet)
-{
+static void route_mac(node_t *source, vpn_packet_t *packet) {
subnet_t *subnet;
mac_t dest;
- cp();
-
-
/* Learn source address */
if(source == myself) {
/* 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);
+ broadcast_packet_helper(source, packet);
return;
}
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;
+
+ 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 && type == ETH_P_IP && packet->len >= ether_size + ip_size)
+ packet->priority = packet->data[15];
+
// 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) {
- if(packet->data[20] & 0x40) {
+ 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);
+ 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) {
+ } 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);
}
+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;
-void route(node_t *source, vpn_packet_t *packet)
-{
- cp();
+ 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;
+ }
+}
+
+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;
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;
}
}
break;
case RMODE_HUB:
- broadcast_packet(source, packet);
+ broadcast_packet_helper(source, packet);
break;
}
}