/*
route.c -- routing
- Copyright (C) 2000-2003 Ivo Timmermans <ivo@o2w.nl>,
- 2000-2003 Guus Sliepen <guus@sliepen.eu.org>
+ Copyright (C) 2000-2004 Ivo Timmermans <ivo@tinc-vpn.org>,
+ 2000-2004 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
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- $Id: route.c,v 1.1.2.70 2003/12/12 19:52:25 guus Exp $
+ $Id$
*/
#include "system.h"
-#ifdef HAVE_NET_ETHERNET_H
-#include <net/ethernet.h>
-#endif
-#ifdef HAVE_NET_IF_ARP_H
-#include <net/if_arp.h>
-#endif
-#ifdef HAVE_NETINET_IP_ICMP_H
-#include <netinet/ip_icmp.h>
-#endif
-#ifdef HAVE_NETINET_ICMP6_H
-#include <netinet/icmp6.h>
-#endif
-#ifdef HAVE_NETINET_IF_ETHER_H
-#include <netinet/if_ether.h>
-#endif
-
#include "avl_tree.h"
#include "connection.h"
#include "ethernet.h"
rmode_t routing_mode = RMODE_ROUTER;
bool priorityinheritance = false;
int macexpire = 600;
-int multicastexpire = 375;
bool overwrite_mac = false;
mac_t mymac = {{0xFE, 0xFD, 0, 0, 0, 0}};
/* RFC 1071 */
-static uint16_t inet_checksum(void *data, int len, uint16_t prevsum)
+static __inline__ uint16_t inet_checksum(void *data, int len, uint16_t prevsum)
{
uint16_t *p = data;
uint32_t checksum = prevsum ^ 0xFFFF;
return ~checksum;
}
-static bool ratelimit(int frequency) {
+static __inline__ bool ratelimit(int frequency) {
static time_t lasttime = 0;
static int count = 0;
return false;
}
-static bool checklength(node_t *source, vpn_packet_t *packet, length_t length) {
+static __inline__ 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);
return false;
return true;
}
-static void learn_mac(mac_t *address)
+static __inline__ void learn_mac(mac_t *address)
{
subnet_t *subnet;
avl_node_t *node;
}
}
-static void route_mac(node_t *source, vpn_packet_t *packet)
+static __inline__ void route_mac(node_t *source, vpn_packet_t *packet)
{
subnet_t *subnet;
/* RFC 792 */
-static void route_ipv4_unreachable(node_t *source, vpn_packet_t *packet, uint8_t code)
+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};
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;
/* Fill in ICMP header */
- icmp.icmp_type = ICMP_DEST_UNREACH;
+ icmp.icmp_type = type;
icmp.icmp_code = code;
icmp.icmp_cksum = 0;
memcpy(packet->data + ether_size + ip_size, &icmp, icmp_size);
packet->len = ether_size + ip_size + icmp_size + oldlen;
-
+
send_packet(source, packet);
}
-static void route_ipv4_unicast(node_t *source, vpn_packet_t *packet)
+/* RFC 791 */
+
+static __inline__ void fragment_ipv4_packet(node_t *dest, vpn_packet_t *packet) {
+ 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;
+
+ if(ip.ip_hl != ip_size / 4)
+ return;
+
+ 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 (%d)"), 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);
+
+ offset = packet->data + ether_size + ip_size;
+ maxlen = (dest->mtu - ether_size - ip_size) & ~0x7;
+ 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);
+ todo -= len;
+ offset += len;
+
+ ip.ip_len = htons(ip_size + len);
+ ip.ip_off = htons(ip_off | origf | (todo ? IP_MF : 0));
+ ip.ip_sum = 0;
+ ip.ip_sum = inet_checksum(&ip, ip_size, ~0);
+ memcpy(fragment.data, packet->data, ether_size);
+ memcpy(fragment.data + ether_size, &ip, ip_size);
+ fragment.len = ether_size + ip_size + len;
+
+ send_packet(dest, &fragment);
+
+ ip_off += len / 8;
+ }
+}
+
+static __inline__ void route_ipv4_unicast(node_t *source, vpn_packet_t *packet)
{
subnet_t *subnet;
+ node_t *via;
cp();
packet->data[32],
packet->data[33]);
- route_ipv4_unreachable(source, packet, ICMP_NET_UNKNOWN);
+ route_ipv4_unreachable(source, packet, ICMP_DEST_UNREACH, ICMP_NET_UNKNOWN);
return;
}
}
if(!subnet->owner->status.reachable)
- route_ipv4_unreachable(source, packet, ICMP_NET_UNREACH);
+ route_ipv4_unreachable(source, packet, ICMP_DEST_UNREACH, ICMP_NET_UNREACH);
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(packet->data[20] & 0x40) {
+ packet->len = via->mtu;
+ route_ipv4_unreachable(source, packet, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED);
+ } else {
+ fragment_ipv4_packet(via, packet);
+ }
+
+ return;
+ }
+
send_packet(subnet->owner, packet);
}
-static void route_ipv4(node_t *source, vpn_packet_t *packet)
+static __inline__ void route_ipv4(node_t *source, vpn_packet_t *packet)
{
cp();
if(!checklength(source, packet, ether_size + ip_size))
return;
-#if 0
- if(packet->data[30] & 0xf0 == 0xe0) {
- route_ipv4_multicast(source, packet);
- return;
- }
-#endif
-
route_ipv4_unicast(source, packet);
}
/* RFC 2463 */
-static void route_ipv6_unreachable(node_t *source, vpn_packet_t *packet, uint8_t code)
+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};
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;
/* Fill in ICMP header */
- icmp6.icmp6_type = ICMP6_DST_UNREACH;
+ icmp6.icmp6_type = type;
icmp6.icmp6_code = code;
icmp6.icmp6_cksum = 0;
send_packet(source, packet);
}
-static void route_ipv6_unicast(node_t *source, vpn_packet_t *packet)
+static __inline__ void route_ipv6_unicast(node_t *source, vpn_packet_t *packet)
{
subnet_t *subnet;
+ node_t *via;
cp();
ntohs(*(uint16_t *) &packet->data[50]),
ntohs(*(uint16_t *) &packet->data[52]));
- route_ipv6_unreachable(source, packet, ICMP6_DST_UNREACH_ADDR);
+ route_ipv6_unreachable(source, packet, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_ADDR);
return;
}
}
if(!subnet->owner->status.reachable)
- route_ipv6_unreachable(source, packet, ICMP6_DST_UNREACH_NOROUTE);
-
- send_packet(subnet->owner, packet);
-}
-
-#ifdef ENABLE_MULTICAST
-static void route_ipv6_multicast(node_t *source, vpn_packet_t *packet)
-{
- avl_node_t *node;
- subnet_t *subnet, search = {0};
-
- cp();
-
- search.type = SUBNET_IPV6;
- search.net.ipv6.address = *(ipv6_t *)(packet->data + ether_size + ip6_size + icmp6_size);
- search.net.ipv6.prefixlength = 128;
- search.owner = NULL;
+ route_ipv6_unreachable(source, packet, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOROUTE);
- ifdebug(TRAFFIC) logger(LOG_INFO, _("Multicasting packet of %d bytes from %s (%s)"), packet->len, source->name, source->hostname);
-
- for(node = avl_search_closest_smaller_node(myself->subnet_tree, &search); node; node = node->next) {
- subnet = node->data;
-
- if(subnet->type != SUBNET_IPV6 || memcmp(&subnet->net.ipv6.address, packet->data + ether_size + ip6_size + icmp6_size, sizeof(ipv6_t)))
- break;
-
- if(subnet->owner != source)
- send_packet(subnet->owner, packet);
+ 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);
+ return;
}
+
+ send_packet(subnet->owner, packet);
}
-#endif
/* RFC 2461 */
send_packet(source, packet);
}
-/* RFC 2710 */
-
-#ifdef ENABLE_MULTICAST
-static void route_membershipreport(node_t *source, vpn_packet_t *packet)
-{
- struct ip6_hdr ip6;
- struct icmp6_hdr icmp6;
- subnet_t *subnet, search = {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;
-
- cp();
-
- if(!checklength(source, packet, ether_size + ip6_size + icmp6_size + sizeof(ipv6_t)))
- return;
-
- if(source != myself) {
- ifdebug(TRAFFIC) logger(LOG_WARNING, _("Got membership report from %s (%s) while in router mode!"), source->name, source->hostname);
- return;
- }
-
- /* Copy headers from packet to structs on the stack */
-
- memcpy(&ip6, packet->data + ether_size, ip6_size);
- memcpy(&icmp6, packet->data + ether_size + ip6_size + 8, icmp6_size);
-
- /* Create pseudo header */
-
- pseudo.ip6_src = ip6.ip6_src;
- pseudo.ip6_dst = ip6.ip6_dst;
- pseudo.length = htonl(icmp6_size + sizeof(ipv6_t));
- 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 + 8 + icmp6_size, sizeof(ipv6_t), checksum);
-
- if(checksum) {
- ifdebug(TRAFFIC) logger(LOG_WARNING, _("Cannot route packet: checksum error for membership report"));
- return;
- }
-
- /* Check if the IPv6 address exists on the VPN */
-
- search.type = SUBNET_IPV6;
- search.net.ipv6.address = *(ipv6_t *)(packet->data + ether_size + ip6_size + 8 + icmp6_size);
- search.net.ipv6.prefixlength = 128;
- search.owner = myself;
-
- subnet = avl_search(myself->subnet_tree, &search);
-
- if(!subnet) {
- avl_node_t *node;
- connection_t *c;
-
- ifdebug(TRAFFIC) logger(LOG_WARNING, _("Learned new IPv6 multicast address %hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx"),
- ntohs(*(uint16_t *) &packet->data[70]),
- ntohs(*(uint16_t *) &packet->data[72]),
- ntohs(*(uint16_t *) &packet->data[74]),
- ntohs(*(uint16_t *) &packet->data[76]),
- ntohs(*(uint16_t *) &packet->data[78]),
- ntohs(*(uint16_t *) &packet->data[80]),
- ntohs(*(uint16_t *) &packet->data[82]),
- ntohs(*(uint16_t *) &packet->data[84]));
-
- subnet = new_subnet();
- subnet->type = SUBNET_IPV6;
- subnet->net.ipv6.address = *(ipv6_t *)(packet->data + ether_size + ip6_size + 8 + icmp6_size);
- subnet->net.ipv6.prefixlength = 128;
- subnet->expires = now + multicastexpire;
- subnet_add(myself, subnet);
-
- /* And tell all other tinc daemons it's ours */
-
- for(node = connection_tree->head; node; node = node->next) {
- c = node->data;
- if(c->status.active)
- send_add_subnet(c, subnet);
- }
- }
-
- if(subnet->expires)
- subnet->expires = now + multicastexpire;
-}
-#endif
-
-static void route_ipv6(node_t *source, vpn_packet_t *packet)
+static __inline__ void route_ipv6(node_t *source, vpn_packet_t *packet)
{
cp();
return;
}
-#ifdef ENABLE_MULTICAST
- if(packet->data[20] == IPPROTO_HOPOPTS && checklength(source, packet, ether_size + ip6_size + 8)
- && packet->data[54] == IPPROTO_ICMPV6 && checklength(source, packet, ether_size + ip6_size + 8 + icmp6_size)
- && packet->data[62] == ICMP6_MEMBERSHIP_REPORT) {
- route_membershipreport(source, packet);
- return;
- }
-
- if(packet->data[38] == 0xff && packet->data[39] & 0x0c) {
- route_ipv6_multicast(source, packet);
- return;
- }
-#endif
-
route_ipv6_unicast(source, packet);
}
projects / tinc / blobdiff