/*
route.c -- routing
- Copyright (C) 2000-2002 Ivo Timmermans <ivo@o2w.nl>,
- 2000-2002 Guus Sliepen <guus@sliepen.eu.org>
+ Copyright (C) 2000-2003 Ivo Timmermans <ivo@o2w.nl>,
+ 2000-2003 Guus Sliepen <guus@sliepen.eu.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 1.1.2.46 2002/09/09 22:33:16 guus Exp $
+ $Id: route.c,v 1.1.2.66 2003/10/01 09:14:01 guus Exp $
*/
-#include "config.h"
+#include "system.h"
-#ifdef HAVE_SYS_PARAM_H
-#include <sys/param.h>
-#endif
-#include <sys/socket.h>
-#include <netinet/in.h>
-#ifdef HAVE_NET_IF_H
-#include <net/if.h>
-#endif
#ifdef HAVE_NET_ETHERNET_H
#include <net/ethernet.h>
#endif
-#ifdef HAVE_NETINET_IN_SYSTM_H
-#include <netinet/in_systm.h>
+#ifdef HAVE_NET_IF_ARP_H
+#include <net/if_arp.h>
#endif
-#include <netinet/ip6.h>
+#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>
-#include <utils.h>
-#include <xalloc.h>
-#include <syslog.h>
-#include <string.h>
-#ifdef HAVE_INTTYPES_H
-#include <inttypes.h>
#endif
-#include <avl_tree.h>
-
-#include "net.h"
+#include "avl_tree.h"
#include "connection.h"
-#include "subnet.h"
-#include "route.h"
-#include "protocol.h"
#include "device.h"
+#include "ethernet.h"
+#include "ipv4.h"
+#include "ipv6.h"
+#include "logger.h"
+#include "net.h"
+#include "protocol.h"
+#include "route.h"
+#include "subnet.h"
+#include "utils.h"
-#include "system.h"
+rmode_t routing_mode = RMODE_ROUTER;
+bool priorityinheritance = false;
+int macexpire = 600;
+bool overwrite_mac = false;
+mac_t mymac = {{0xFE, 0xFD, 0, 0, 0, 0}};
-#ifndef ETHER_ADDR_LEN
-#define ETHER_ADDR_LEN 6
-#endif
+/* RFC 1071 */
-int routing_mode = RMODE_ROUTER;
-int priorityinheritance = 0;
-int macexpire = 600;
-subnet_t mymac;
+static uint16_t inet_checksum(void *data, int len, uint16_t prevsum)
+{
+ uint16_t *p = data;
+ uint32_t checksum = prevsum ^ 0xFFFF;
+
+ while(len >= 2) {
+ checksum += *p++;
+ len -= 2;
+ }
+
+ if(len)
+ checksum += *(unsigned char *)p;
+
+ while(checksum >> 16)
+ checksum = (checksum & 0xFFFF) + (checksum >> 16);
+
+ return ~checksum;
+}
+
+static bool ratelimit(void) {
+ static time_t lasttime = 0;
+
+ if(lasttime == now)
+ return true;
-void learn_mac(mac_t *address)
+ lasttime = now;
+ return false;
+}
+
+static void learn_mac(mac_t *address)
{
subnet_t *subnet;
avl_node_t *node;
/* If we don't know this MAC address yet, store it */
if(!subnet || subnet->owner != myself) {
- if(debug_lvl >= DEBUG_TRAFFIC)
- syslog(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]);
/* And tell all other tinc daemons it's our MAC */
for(node = connection_tree->head; node; node = node->next) {
- c = (connection_t *) node->data;
+ c = node->data;
if(c->status.active)
send_add_subnet(c, subnet);
}
for(node = myself->subnet_tree->head; node; node = next) {
next = node->next;
- s = (subnet_t *) node->data;
+ s = node->data;
if(s->type == SUBNET_MAC && s->net.mac.lastseen && s->net.mac.lastseen + macexpire < now) {
- if(debug_lvl >= DEBUG_TRAFFIC)
- syslog(LOG_INFO, _("MAC address %hx:%hx:%hx:%hx:%hx:%hx expired"),
+ ifdebug(TRAFFIC) logger(LOG_INFO, _("MAC address %hx:%hx:%hx:%hx:%hx:%hx expired"),
s->net.mac.address.x[0], s->net.mac.address.x[1],
s->net.mac.address.x[2], s->net.mac.address.x[3],
s->net.mac.address.x[4], s->net.mac.address.x[5]);
for(node2 = connection_tree->head; node2; node2 = node2->next) {
- c = (connection_t *) node2->data;
+ c = node2->data;
if(c->status.active)
send_del_subnet(c, s);
}
}
}
-node_t *route_mac(vpn_packet_t *packet)
+static node_t *route_mac(vpn_packet_t *packet)
{
subnet_t *subnet;
return NULL;
}
-node_t *route_ipv4(vpn_packet_t *packet)
+/* RFC 792 */
+
+static void route_ipv4_unreachable(vpn_packet_t *packet, uint8_t code)
+{
+ struct ip *hdr;
+ struct icmp *icmp;
+
+ struct in_addr ip_src;
+ struct in_addr ip_dst;
+ uint32_t oldlen;
+
+ if(ratelimit())
+ return;
+
+ cp();
+
+ hdr = (struct ip *)(packet->data + 14);
+ icmp = (struct icmp *)(packet->data + 14 + 20);
+
+ /* Remember original source and destination */
+
+ memcpy(&ip_src, &hdr->ip_src, 4);
+ memcpy(&ip_dst, &hdr->ip_dst, 4);
+ oldlen = packet->len - 14;
+
+ if(oldlen >= IP_MSS - sizeof(*hdr) - sizeof(*icmp))
+ oldlen = IP_MSS - sizeof(*hdr) - sizeof(*icmp);
+
+ /* Copy first part of original contents to ICMP message */
+
+ memmove(&icmp->icmp_ip, hdr, oldlen);
+
+ /* Fill in IPv4 header */
+
+ hdr->ip_v = 4;
+ hdr->ip_hl = sizeof(*hdr) / 4;
+ hdr->ip_tos = 0;
+ hdr->ip_len = htons(20 + 8 + oldlen);
+ hdr->ip_id = 0;
+ hdr->ip_off = 0;
+ hdr->ip_ttl = 255;
+ hdr->ip_p = IPPROTO_ICMP;
+ hdr->ip_sum = 0;
+ memcpy(&hdr->ip_src, &ip_dst, 4);
+ memcpy(&hdr->ip_dst, &ip_src, 4);
+
+ hdr->ip_sum = inet_checksum(hdr, 20, ~0);
+
+ /* Fill in ICMP header */
+
+ icmp->icmp_type = ICMP_DEST_UNREACH;
+ icmp->icmp_code = code;
+ icmp->icmp_cksum = 0;
+
+ icmp->icmp_cksum = inet_checksum(icmp, 8 + oldlen, ~0);
+
+ packet->len = 14 + 20 + 8 + oldlen;
+
+ write_packet(packet);
+}
+
+static node_t *route_ipv4(vpn_packet_t *packet)
{
subnet_t *subnet;
if(priorityinheritance)
packet->priority = packet->data[15];
- subnet = lookup_subnet_ipv4((ipv4_t *) & packet->data[30]);
+ subnet = lookup_subnet_ipv4((ipv4_t *) &packet->data[30]);
if(!subnet) {
- if(debug_lvl >= DEBUG_TRAFFIC) {
- syslog(LOG_WARNING, _("Cannot route packet: unknown IPv4 destination address %d.%d.%d.%d"),
+ ifdebug(TRAFFIC) logger(LOG_WARNING, _("Cannot route packet: unknown IPv4 destination address %d.%d.%d.%d"),
packet->data[30], packet->data[31], packet->data[32],
packet->data[33]);
- }
+ route_ipv4_unreachable(packet, ICMP_NET_UNKNOWN);
return NULL;
}
+
+ if(!subnet->owner->status.reachable)
+ route_ipv4_unreachable(packet, ICMP_NET_UNREACH);
return subnet->owner;
}
-node_t *route_ipv6(vpn_packet_t *packet)
+/* RFC 2463 */
+
+static void route_ipv6_unreachable(vpn_packet_t *packet, uint8_t code)
+{
+ struct ip6_hdr *hdr;
+ struct icmp6_hdr *icmp;
+ 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())
+ return;
+
+ cp();
+
+ hdr = (struct ip6_hdr *)(packet->data + 14);
+ icmp = (struct icmp6_hdr *)(packet->data + 14 + sizeof(*hdr));
+
+ /* Remember original source and destination */
+
+ memcpy(&pseudo.ip6_src, &hdr->ip6_dst, 16);
+ memcpy(&pseudo.ip6_dst, &hdr->ip6_src, 16);
+ pseudo.length = ntohs(hdr->ip6_plen) + sizeof(*hdr);
+
+ if(pseudo.length >= IP_MSS - sizeof(*hdr) - sizeof(*icmp))
+ pseudo.length = IP_MSS - sizeof(*hdr) - sizeof(*icmp);
+
+ /* Copy first part of original contents to ICMP message */
+
+ memmove(((char *)icmp) + sizeof(*icmp), hdr, pseudo.length);
+
+ /* Fill in IPv6 header */
+
+ hdr->ip6_flow = htonl(0x60000000UL);
+ hdr->ip6_plen = htons(sizeof(*icmp) + pseudo.length);
+ hdr->ip6_nxt = IPPROTO_ICMPV6;
+ hdr->ip6_hlim = 255;
+ memcpy(&hdr->ip6_dst, &pseudo.ip6_dst, 16);
+ memcpy(&hdr->ip6_src, &pseudo.ip6_src, 16);
+
+ /* Fill in ICMP header */
+
+ icmp->icmp6_type = ICMP6_DST_UNREACH;
+ icmp->icmp6_code = code;
+ icmp->icmp6_cksum = 0;
+
+ /* Create pseudo header */
+
+ pseudo.length = htonl(sizeof(*icmp) + pseudo.length);
+ pseudo.next = htonl(IPPROTO_ICMPV6);
+
+ /* Generate checksum */
+
+ checksum = inet_checksum(&pseudo, sizeof(pseudo), ~0);
+ checksum = inet_checksum(icmp, ntohl(pseudo.length), checksum);
+
+ icmp->icmp6_cksum = checksum;
+
+ packet->len = 14 + sizeof(*hdr) + ntohl(pseudo.length);
+
+ write_packet(packet);
+}
+
+static node_t *route_ipv6(vpn_packet_t *packet)
{
subnet_t *subnet;
cp();
- subnet = lookup_subnet_ipv6((ipv6_t *) & packet->data[38]);
+ subnet = lookup_subnet_ipv6((ipv6_t *) &packet->data[38]);
if(!subnet) {
- if(debug_lvl >= DEBUG_TRAFFIC) {
- syslog(LOG_WARNING, _("Cannot route packet: unknown IPv6 destination address %hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx"),
- 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]));
- }
+ ifdebug(TRAFFIC) logger(LOG_WARNING, _("Cannot route packet: unknown IPv6 destination address %hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx"),
+ 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(packet, ICMP6_DST_UNREACH_ADDR);
return NULL;
}
+ if(!subnet->owner->status.reachable)
+ route_ipv6_unreachable(packet, ICMP6_DST_UNREACH_NOROUTE);
+
return subnet->owner;
}
-uint16_t inet_checksum(uint16_t *data, int len, uint16_t prevsum)
-{
- uint32_t checksum = prevsum ^ 0xFFFF;
-
- while(len--)
- checksum += ntohs(*data++);
+/* RFC 2461 */
- while(checksum >> 16)
- checksum = (checksum & 0xFFFF) + (checksum >> 16);
-
- return checksum ^ 0xFFFF;
-}
-
-void route_neighborsol(vpn_packet_t *packet)
+static void route_neighborsol(vpn_packet_t *packet)
{
struct ip6_hdr *hdr;
struct nd_neighbor_solicit *ns;
struct in6_addr ip6_src; /* source address */
struct in6_addr ip6_dst; /* destination address */
uint32_t length;
- uint8_t junk[4];
+ uint32_t next;
} pseudo;
cp();
/* First, snatch the source address from the neighbor solicitation packet */
- memcpy(mymac.net.mac.address.x, packet->data + 6, 6);
+ if(overwrite_mac)
+ memcpy(mymac.x, packet->data + 6, 6);
/* Check if this is a valid neighbor solicitation request */
if(ns->nd_ns_hdr.icmp6_type != ND_NEIGHBOR_SOLICIT ||
opt->nd_opt_type != ND_OPT_SOURCE_LINKADDR) {
- if(debug_lvl > DEBUG_TRAFFIC) {
- syslog(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;
}
memcpy(&pseudo.ip6_src, &hdr->ip6_src, 16);
memcpy(&pseudo.ip6_dst, &hdr->ip6_dst, 16);
pseudo.length = htonl(sizeof(*ns) + sizeof(*opt) + 6);
- pseudo.junk[0] = pseudo.junk[1] = pseudo.junk[2] = 0;
- pseudo.junk[3] = IPPROTO_ICMPV6;
+ pseudo.next = htonl(IPPROTO_ICMPV6);
/* Generate checksum */
- checksum = inet_checksum((uint16_t *) & pseudo, sizeof(pseudo) / 2, ~0);
- checksum = inet_checksum((uint16_t *) ns, sizeof(*ns) / 2 + 4, checksum);
+ checksum = inet_checksum(&pseudo, sizeof(pseudo), ~0);
+ checksum = inet_checksum(ns, sizeof(*ns) + 8, checksum);
if(checksum) {
- if(debug_lvl >= DEBUG_TRAFFIC)
- syslog(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;
}
/* Check if the IPv6 address exists on the VPN */
- subnet = lookup_subnet_ipv6((ipv6_t *) & ns->nd_ns_target);
+ subnet = lookup_subnet_ipv6((ipv6_t *) &ns->nd_ns_target);
if(!subnet) {
- if(debug_lvl >= DEBUG_TRAFFIC) {
- syslog(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]),
- ntohs(((uint16_t *) & ns->nd_ns_target)[3]),
- ntohs(((uint16_t *) & ns->nd_ns_target)[4]),
- ntohs(((uint16_t *) & ns->nd_ns_target)[5]),
- ntohs(((uint16_t *) & ns->nd_ns_target)[6]),
- ntohs(((uint16_t *) & ns->nd_ns_target)[7]));
- }
+ 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]),
+ ntohs(((uint16_t *) &ns->nd_ns_target)[3]),
+ ntohs(((uint16_t *) &ns->nd_ns_target)[4]),
+ ntohs(((uint16_t *) &ns->nd_ns_target)[5]),
+ ntohs(((uint16_t *) &ns->nd_ns_target)[6]),
+ ntohs(((uint16_t *) &ns->nd_ns_target)[7]));
return;
}
memcpy(&pseudo.ip6_src, &hdr->ip6_src, 16);
memcpy(&pseudo.ip6_dst, &hdr->ip6_dst, 16);
pseudo.length = htonl(sizeof(*ns) + sizeof(*opt) + 6);
- pseudo.junk[0] = pseudo.junk[1] = pseudo.junk[2] = 0;
- pseudo.junk[3] = IPPROTO_ICMPV6;
+ pseudo.next = htonl(IPPROTO_ICMPV6);
/* Generate checksum */
- checksum = inet_checksum((uint16_t *) & pseudo, sizeof(pseudo) / 2, ~0);
- checksum = inet_checksum((uint16_t *) ns, sizeof(*ns) / 2 + 4, checksum);
+ checksum = inet_checksum(&pseudo, sizeof(pseudo), ~0);
+ checksum = inet_checksum(ns, sizeof(*ns) + 8, checksum);
- ns->nd_ns_hdr.icmp6_cksum = htons(checksum);
+ ns->nd_ns_hdr.icmp6_cksum = checksum;
write_packet(packet);
}
-void route_arp(vpn_packet_t *packet)
+/* RFC 826 */
+
+static void route_arp(vpn_packet_t *packet)
{
struct ether_arp *arp;
subnet_t *subnet;
/* First, snatch the source address from the ARP packet */
- memcpy(mymac.net.mac.address.x, packet->data + 6, 6);
+ if(overwrite_mac)
+ memcpy(mymac.x, packet->data + 6, 6);
/* This routine generates replies to ARP requests.
You don't need to set NOARP flag on the interface anymore (which is broken on FreeBSD).
if(ntohs(arp->arp_hrd) != ARPHRD_ETHER || ntohs(arp->arp_pro) != ETHERTYPE_IP ||
arp->arp_hln != ETHER_ADDR_LEN || arp->arp_pln != 4 || ntohs(arp->arp_op) != ARPOP_REQUEST) {
- if(debug_lvl > DEBUG_TRAFFIC) {
- syslog(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) {
- if(debug_lvl >= DEBUG_TRAFFIC) {
- syslog(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;
}
cp();
+ if(packet->len < 14) {
+ ifdebug(TRAFFIC) logger(LOG_WARNING, _("Read too short packet"));
+ return;
+ }
+
/* FIXME: multicast? */
switch (routing_mode) {
type = ntohs(*((uint16_t *)(&packet->data[12])));
switch (type) {
case 0x0800:
+ if(packet->len < 34) {
+ ifdebug(TRAFFIC) logger(LOG_WARNING, _("Read too short packet"));
+ return;
+ }
+
n = route_ipv4(packet);
break;
case 0x86DD:
- if(packet->data[20] == IPPROTO_ICMPV6 && packet->data[54] == ND_NEIGHBOR_SOLICIT) {
+ if(packet->len < 54) {
+ ifdebug(TRAFFIC) logger(LOG_WARNING, _("Read too short packet"));
+ return;
+ }
+
+ if(packet->data[20] == IPPROTO_ICMPV6 && packet->len >= 62 && packet->data[54] == ND_NEIGHBOR_SOLICIT) {
route_neighborsol(packet);
return;
}
break;
case 0x0806:
+ if(packet->len < 42) {
+ ifdebug(TRAFFIC) logger(LOG_WARNING, _("Read too short packet"));
+ return;
+ }
+
route_arp(packet);
return;
default:
- if(debug_lvl >= DEBUG_TRAFFIC)
- syslog(LOG_WARNING, _("Cannot route packet: unknown type %hx"), type);
+ ifdebug(TRAFFIC) logger(LOG_WARNING, _("Cannot route packet: unknown type %hx"), type);
return;
}
if(n)
void route_incoming(node_t *source, vpn_packet_t *packet)
{
+ if(packet->len < 14) {
+ ifdebug(TRAFFIC) logger(LOG_WARNING, _("Got too short packet from %s (%s)"),
+ source->name, source->hostname);
+ return;
+ }
+
switch (routing_mode) {
case RMODE_ROUTER:
{
type = ntohs(*((uint16_t *)(&packet->data[12])));
switch (type) {
case 0x0800:
+ if(packet->len < 34) {
+ ifdebug(TRAFFIC) logger(LOG_WARNING, _("Read too short packet"));
+ return;
+ }
+
n = route_ipv4(packet);
break;
case 0x86DD:
+ if(packet->len < 54) {
+ ifdebug(TRAFFIC) logger(LOG_WARNING, _("Read too short packet"));
+ return;
+ }
+
n = route_ipv6(packet);
break;
if(n) {
if(n == myself) {
- memcpy(packet->data, mymac.net.mac.address.x, 6);
+ if(overwrite_mac)
+ memcpy(packet->data, mymac.x, 6);
write_packet(packet);
} else
send_packet(n, packet);
projects / tinc / blobdiff