/*
route.c -- routing
- Copyright (C) 2000-2003 Ivo Timmermans <ivo@o2w.nl>,
- 2000-2003 Guus Sliepen <guus@sliepen.eu.org>
+ Copyright (C) 2000-2005 Ivo Timmermans,
+ 2000-2006 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 1.1.2.71 2003/12/13 21:50:26 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"
/* RFC 1071 */
-static __inline__ 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;
return ~checksum;
}
-static __inline__ bool ratelimit(int frequency) {
+static bool ratelimit(int frequency) {
static time_t lasttime = 0;
static int count = 0;
return false;
}
-static __inline__ bool checklength(node_t *source, vpn_packet_t *packet, length_t length) {
+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);
return false;
return true;
}
-static __inline__ void learn_mac(mac_t *address)
+static void learn_mac(mac_t *address)
{
subnet_t *subnet;
avl_node_t *node;
}
}
-static __inline__ 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)
- learn_mac((mac_t *)(&packet->data[6]));
+ if(source == myself) {
+ mac_t src;
+ memcpy(&src, &packet->data[6], sizeof src);
+ learn_mac(&src);
+ }
/* Lookup destination address */
- subnet = lookup_subnet_mac((mac_t *)(&packet->data[0]));
+ memcpy(&dest, &packet->data[0], sizeof dest);
+ subnet = lookup_subnet_mac(&dest);
if(!subnet) {
broadcast_packet(source, packet);
/* 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 __inline__ void route_ipv4_unicast(node_t *source, vpn_packet_t *packet)
+/* RFC 791 */
+
+static 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 (%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);
+
+ 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 void route_ipv4_unicast(node_t *source, vpn_packet_t *packet)
{
subnet_t *subnet;
+ node_t *via;
+ ipv4_t dest;
cp();
- subnet = lookup_subnet_ipv4((ipv4_t *) &packet->data[30]);
+ 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"),
source->name, source->hostname,
- packet->data[30],
- packet->data[31],
- packet->data[32],
- packet->data[33]);
+ dest.x[0],
+ dest.x[1],
+ dest.x[2],
+ dest.x[3]);
- 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 __inline__ void route_ipv4(node_t *source, vpn_packet_t *packet)
+static void route_ipv4(node_t *source, vpn_packet_t *packet)
{
cp();
/* 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 __inline__ 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();
- subnet = lookup_subnet_ipv6((ipv6_t *) &packet->data[38]);
+ 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"),
source->name, source->hostname,
- ntohs(*(uint16_t *) &packet->data[38]),
- ntohs(*(uint16_t *) &packet->data[40]),
- ntohs(*(uint16_t *) &packet->data[42]),
- ntohs(*(uint16_t *) &packet->data[44]),
- ntohs(*(uint16_t *) &packet->data[46]),
- ntohs(*(uint16_t *) &packet->data[48]),
- ntohs(*(uint16_t *) &packet->data[50]),
- ntohs(*(uint16_t *) &packet->data[52]));
-
- route_ipv6_unreachable(source, packet, ICMP6_DST_UNREACH_ADDR);
+ ntohs(dest.x[0]),
+ ntohs(dest.x[1]),
+ ntohs(dest.x[2]),
+ ntohs(dest.x[3]),
+ ntohs(dest.x[4]),
+ ntohs(dest.x[5]),
+ ntohs(dest.x[6]),
+ ntohs(dest.x[7]));
+
+ 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);
+ route_ipv6_unreachable(source, packet, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOROUTE);
+
+ 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);
}
send_packet(source, packet);
}
-static __inline__ void route_ipv6(node_t *source, vpn_packet_t *packet)
+static void route_ipv6(node_t *source, vpn_packet_t *packet)
{
cp();
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