/*
route.c -- routing
- Copyright (C) 2000 Ivo Timmermans <itimmermans@bigfoot.com>,
- 2000 Guus Sliepen <guus@sliepen.warande.net>
+ Copyright (C) 2000-2002 Ivo Timmermans <itimmermans@bigfoot.com>,
+ 2000-2002 Guus Sliepen <guus@sliepen.warande.net>
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 1.1.2.2 2000/11/04 22:57:33 guus Exp $
+ $Id: route.c,v 1.1.2.37 2002/03/19 00:08:23 guus Exp $
*/
#include "config.h"
+#if defined(HAVE_FREEBSD) || defined(HAVE_OPENBSD)
+ #include <sys/param.h>
+#endif
+#include <sys/socket.h>
+#include <netinet/in.h>
+#if defined(HAVE_SOLARIS) || defined(HAVE_OPENBSD)
+ #include <net/if.h>
+ #define ETHER_ADDR_LEN 6
+#else
+ #include <net/ethernet.h>
+#endif
+#include <netinet/ip6.h>
+#include <netinet/icmp6.h>
+#include <netinet/if_ether.h>
#include <utils.h>
#include <xalloc.h>
+#include <syslog.h>
+#include <string.h>
+
+#include <avl_tree.h>
#include "net.h"
-#include "connlist.h"
+#include "connection.h"
+#include "subnet.h"
+#include "route.h"
+#include "protocol.h"
+#include "device.h"
#include "system.h"
-int routing_mode = 0; /* Will be used to determine if we route by MAC or by payload's protocol */
+int routing_mode = RMODE_ROUTER;
+int priorityinheritance = 0;
+int macexpire = 600;
+subnet_t mymac;
-conn_list_t *route_packet(vpn_packet_t *packet)
+void learn_mac(mac_t *address)
{
- unsigned short type;
+ subnet_t *subnet;
+ avl_node_t *node;
+ connection_t *c;
cp
- type = ntohs(*((unsigned short*)(&packet.data[12])))
+ subnet = lookup_subnet_mac(address);
- if(routing_mode)
+ /* If we don't know this MAC address yet, store it */
+
+ if(!subnet || subnet->owner!=myself)
{
- return route_mac(packet);
+ if(debug_lvl >= DEBUG_TRAFFIC)
+ syslog(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]);
+
+ subnet = new_subnet();
+ subnet->type = SUBNET_MAC;
+ memcpy(&subnet->net.mac.address, address, sizeof(mac_t));
+ subnet_add(myself, subnet);
+
+ /* And tell all other tinc daemons it's our MAC */
+
+ for(node = connection_tree->head; node; node = node->next)
+ {
+ c = (connection_t *)node->data;
+ if(c->status.active)
+ send_add_subnet(c, subnet);
+ }
}
- switch(type)
+ subnet->net.mac.lastseen = now;
+}
+
+void age_mac(void)
+{
+ subnet_t *s;
+ connection_t *c;
+ avl_node_t *node, *next, *node2;
+cp
+ for(node = myself->subnet_tree->head; node; node = next)
{
- case 0x0800:
- return route_ipv4(packet);
- case 0x86DD:
- return route_ipv6(packet);
-/*
- case 0x8137:
- return route_ipx(packet);
- case 0x0806:
- return route_arp(packet);
-*/
- default:
- if(debug_lvl >= DEBUG_TRAFFIC)
- {
- syslog(LOG_WARNING, _("Cannot route packet: unknown type %hx"), type);
- }
- return NULL;
- }
+ next = node->next;
+ s = (subnet_t *)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"),
+ 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;
+ if(c->status.active)
+ send_del_subnet(c, s);
+ }
+ subnet_del(myself, s);
+ }
+ }
+cp
}
-conn_list_t *route_mac(vpn_packet_t *packet)
+node_t *route_mac(vpn_packet_t *packet)
{
- conn_list_t *cl;
+ subnet_t *subnet;
cp
- cl = lookup_subnet_mac((mac_t *)(&packet.data[6]));
- if(!cl)
- if(debug_lvl >= DEBUG_TRAFFIC)
- {
- syslog(LOG_WARNING, _("Cannot route packet: unknown destination address %x:%x:%x:%x:%x:%x"),
- packet.data[6],
- packet.data[7],
- packet.data[8],
- packet.data[9],
- packet.data[10],
- packet.data[11]);
- }
-cp
- return cl;
+ /* Learn source address */
+
+ learn_mac((mac_t *)(&packet->data[6]));
+
+ /* Lookup destination address */
+
+ subnet = lookup_subnet_mac((mac_t *)(&packet->data[0]));
+
+ if(subnet)
+ return subnet->owner;
+ else
+ return NULL;
}
+node_t *route_ipv4(vpn_packet_t *packet)
+{
+ subnet_t *subnet;
+cp
+ if(priorityinheritance)
+ packet->priority = packet->data[15];
+
+ subnet = lookup_subnet_ipv4((ipv4_t *)&packet->data[30]);
+cp
+ if(!subnet)
+ {
+ if(debug_lvl >= DEBUG_TRAFFIC)
+ {
+ syslog(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]);
+ }
+
+ return NULL;
+ }
+cp
+ return subnet->owner;
+}
-conn_list_t *route_ipv4(vpn_packet_t *packet)
+node_t *route_ipv6(vpn_packet_t *packet)
{
- ipv4_t dest;
- conn_list_t *cl;
+ subnet_t *subnet;
+cp
+ subnet = lookup_subnet_ipv6((ipv6_t *)&packet->data[38]);
+cp
+ 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(*(short unsigned int *)&packet->data[38]),
+ ntohs(*(short unsigned int *)&packet->data[40]),
+ ntohs(*(short unsigned int *)&packet->data[42]),
+ ntohs(*(short unsigned int *)&packet->data[44]),
+ ntohs(*(short unsigned int *)&packet->data[46]),
+ ntohs(*(short unsigned int *)&packet->data[48]),
+ ntohs(*(short unsigned int *)&packet->data[50]),
+ ntohs(*(short unsigned int *)&packet->data[52]));
+ }
+
+ return NULL;
+ }
cp
- dest = ntohl(*((unsigned long*)(&packet.data[30]);
+ return subnet->owner;
+}
+
+unsigned short int inet_checksum(unsigned short int *data, int len, unsigned short int prevsum)
+{
+ unsigned long int checksum = prevsum ^ 0xFFFF;
+
+ while(len--)
+ checksum += ntohs(*data++);
+
+ while(checksum >> 16)
+ checksum = (checksum & 0xFFFF) + (checksum >> 16);
+
+ return checksum ^ 0xFFFF;
+}
+
+void route_neighborsol(vpn_packet_t *packet)
+{
+ struct ip6_hdr *hdr;
+ struct nd_neighbor_solicit *ns;
+ struct nd_opt_hdr *opt;
+ subnet_t *subnet;
+ short unsigned int checksum;
- cl = lookup_subnet_ipv4(dest);
- if(!cl)
- if(debug_lvl >= DEBUG_TRAFFIC)
- {
- syslog(LOG_WARNING, _("Cannot route packet: unknown destination address %d.%d.%d.%d"),
- packet.data[30], packet.data[31], packet.data[32], packet.data[33]);
- }
+ struct {
+ struct in6_addr ip6_src; /* source address */
+ struct in6_addr ip6_dst; /* destination address */
+ uint32_t length;
+ uint8_t junk[4];
+ } pseudo;
+
+cp
+ hdr = (struct ip6_hdr *)(packet->data + 14);
+ ns = (struct nd_neighbor_solicit *)(packet->data + 14 + sizeof(*hdr));
+ opt = (struct nd_opt_hdr *)(packet->data + 14 + sizeof(*hdr) + sizeof(*ns));
+
+ /* First, snatch the source address from the neighbor solicitation packet */
+
+ memcpy(mymac.net.mac.address.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"));
+ }
+ return;
+ }
+
+ /* Create pseudo header */
+
+ 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;
+
+ /* Generate checksum */
+
+ checksum = inet_checksum((unsigned short int *)&pseudo, sizeof(pseudo)/2, ~0);
+ checksum = inet_checksum((unsigned short int *)ns, sizeof(*ns)/2 + 4, checksum);
+
+ if(checksum)
+ {
+ if(debug_lvl >= DEBUG_TRAFFIC)
+ syslog(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);
+
+ 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]));
+ }
+
+ return;
+ }
+
+ /* Check if it is for our own subnet */
+
+ if(subnet->owner == myself)
+ return; /* silently ignore */
+
+ /* Create neighbor advertation reply */
+
+ memcpy(packet->data, packet->data + ETHER_ADDR_LEN, ETHER_ADDR_LEN); /* copy destination address */
+ packet->data[ETHER_ADDR_LEN*2 - 1] ^= 0xFF; /* mangle source address so it looks like it's not from us */
+
+ memcpy(&hdr->ip6_dst, &hdr->ip6_src, 16); /* swap destination and source protocol address */
+ memcpy(&hdr->ip6_src, &ns->nd_ns_target, 16); /* ... */
+
+ memcpy((char *)opt + sizeof(*opt), packet->data + ETHER_ADDR_LEN, 6); /* add fake source hard addr */
+
+ ns->nd_ns_hdr.icmp6_cksum = 0;
+ ns->nd_ns_hdr.icmp6_type = ND_NEIGHBOR_ADVERT;
+ ns->nd_ns_hdr.icmp6_dataun.icmp6_un_data8[0] = 0x40; /* Set solicited flag */
+ ns->nd_ns_hdr.icmp6_dataun.icmp6_un_data8[1] = ns->nd_ns_hdr.icmp6_dataun.icmp6_un_data8[2] = ns->nd_ns_hdr.icmp6_dataun.icmp6_un_data8[3] = 0;
+ opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
+
+ /* Create pseudo header */
+
+ 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;
+
+ /* Generate checksum */
+
+ checksum = inet_checksum((unsigned short int *)&pseudo, sizeof(pseudo)/2, ~0);
+ checksum = inet_checksum((unsigned short int *)ns, sizeof(*ns)/2 + 4, checksum);
+
+ ns->nd_ns_hdr.icmp6_cksum = htons(checksum);
+
+ write_packet(packet);
cp
- return cl;
}
-conn_list_t *route_ipv6(vpn_packet_t *packet)
+void route_arp(vpn_packet_t *packet)
{
+ struct ether_arp *arp;
+ subnet_t *subnet;
+ unsigned char ipbuf[4];
cp
- syslog(LOG_WARNING, _("Cannot route packet: IPv6 routing not implemented yet"));
+ /* First, snatch the source address from the ARP packet */
+
+ memcpy(mymac.net.mac.address.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).
+ Most of the code here is taken from choparp.c by Takamichi Tateoka (tree@mma.club.uec.ac.jp)
+ */
+
+ arp = (struct ether_arp *)(packet->data + 14);
+
+ /* Check if this is a valid ARP request */
+
+ if(ntohs(arp->arp_hrd) != ARPHRD_ETHER ||
+ ntohs(arp->arp_pro) != ETHERTYPE_IP ||
+ (int) (arp->arp_hln) != ETHER_ADDR_LEN ||
+ (int) (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"));
+ }
+ return;
+ }
+
+ /* Check if the IPv4 address exists on the VPN */
+
+ 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"),
+ arp->arp_tpa[0], arp->arp_tpa[1], arp->arp_tpa[2], arp->arp_tpa[3]);
+ }
+
+ return;
+ }
+
+ /* Check if it is for our own subnet */
+
+ if(subnet->owner == myself)
+ return; /* silently ignore */
+
+ memcpy(packet->data, packet->data + ETHER_ADDR_LEN, ETHER_ADDR_LEN); /* copy destination address */
+ packet->data[ETHER_ADDR_LEN*2 - 1] ^= 0xFF; /* mangle source address so it looks like it's not from us */
+
+ memcpy(ipbuf, arp->arp_tpa, 4); /* save protocol addr */
+ memcpy(arp->arp_tpa, arp->arp_spa, 4); /* swap destination and source protocol address */
+ memcpy(arp->arp_spa, ipbuf, 4); /* ... */
+
+ memcpy(arp->arp_tha, arp->arp_sha, 10); /* set target hard/proto addr */
+ memcpy(arp->arp_sha, packet->data + ETHER_ADDR_LEN, ETHER_ADDR_LEN); /* add fake source hard addr */
+ arp->arp_op = htons(ARPOP_REPLY);
+
+ write_packet(packet);
cp
- return NULL;
+}
+
+void route_outgoing(vpn_packet_t *packet)
+{
+ unsigned short int type;
+ node_t *n = NULL;
+cp
+ /* FIXME: multicast? */
+
+ switch(routing_mode)
+ {
+ case RMODE_ROUTER:
+ type = ntohs(*((unsigned short*)(&packet->data[12])));
+ switch(type)
+ {
+ case 0x0800:
+ n = route_ipv4(packet);
+ break;
+ case 0x86DD:
+ if(packet->data[20] == IPPROTO_ICMPV6 && packet->data[54] == ND_NEIGHBOR_SOLICIT)
+ {
+ route_neighborsol(packet);
+ return;
+ }
+ n = route_ipv6(packet);
+ break;
+ case 0x0806:
+ route_arp(packet);
+ return;
+ default:
+ if(debug_lvl >= DEBUG_TRAFFIC)
+ {
+ syslog(LOG_WARNING, _("Cannot route packet: unknown type %hx"), type);
+ }
+ return;
+ }
+ if(n)
+ send_packet(n, packet);
+ break;
+
+ case RMODE_SWITCH:
+ n = route_mac(packet);
+ if(n)
+ send_packet(n, packet);
+ else
+ broadcast_packet(myself, packet);
+ break;
+
+ case RMODE_HUB:
+ broadcast_packet(myself, packet);
+ break;
+ }
+}
+
+void route_incoming(node_t *source, vpn_packet_t *packet)
+{
+ switch(routing_mode)
+ {
+ case RMODE_ROUTER:
+ {
+ node_t *n = NULL;
+ unsigned short int type;
+
+ type = ntohs(*((unsigned short*)(&packet->data[12])));
+ switch(type)
+ {
+ case 0x0800:
+ n = route_ipv4(packet);
+ break;
+ case 0x86DD:
+ n = route_ipv6(packet);
+ break;
+ default:
+ n = myself;
+ break;
+ }
+
+ if(n)
+ {
+ if(n == myself)
+ {
+ memcpy(packet->data, mymac.net.mac.address.x, 6);
+ write_packet(packet);
+ }
+ else
+ send_packet(n, packet);
+ }
+ }
+ break;
+ case RMODE_SWITCH:
+ {
+ subnet_t *subnet;
+
+ subnet = lookup_subnet_mac((mac_t *)(&packet->data[0]));
+
+ if(subnet)
+ {
+ if(subnet->owner == myself)
+ write_packet(packet);
+ else
+ send_packet(subnet->owner, packet);
+ }
+ else
+ {
+ broadcast_packet(source, packet);
+ write_packet(packet);
+ }
+ }
+ break;
+ case RMODE_HUB:
+ broadcast_packet(source, packet); /* Spread it on */
+ write_packet(packet);
+ break;
+ }
}