/*
route.c -- routing
- Copyright (C) 2000-2003 Ivo Timmermans <ivo@o2w.nl>,
- 2000-2003 Guus Sliepen <guus@sliepen.eu.org>
+ Copyright (C) 2014 Guus Sliepen <guus@meshlink.io>
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
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
- You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software
- Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
-
- $Id: route.c,v 1.1.2.65 2003/09/23 20:59:01 guus Exp $
+ You should have received a copy of the GNU General Public License along
+ with this program; if not, write to the Free Software Foundation, Inc.,
+ 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#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 "device.h"
-#include "ethernet.h"
-#include "ipv4.h"
-#include "ipv6.h"
#include "logger.h"
+#include "meshlink_internal.h"
#include "net.h"
-#include "protocol.h"
#include "route.h"
-#include "subnet.h"
#include "utils.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}};
-
-/* RFC 1071 */
-
-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 checklength(node_t *source, vpn_packet_t *packet, uint16_t length) {
+ assert(length);
-static bool ratelimit(void) {
- static time_t lasttime = 0;
-
- if(lasttime == now)
+ if(packet->len < length) {
+ logger(source->mesh, MESHLINK_WARNING, "Got too short packet from %s", source->name);
+ return false;
+ } else {
return true;
-
- lasttime = now;
- return false;
-}
-
-static void learn_mac(mac_t *address)
-{
- subnet_t *subnet;
- avl_node_t *node;
- connection_t *c;
-
- cp();
-
- subnet = lookup_subnet_mac(address);
-
- /* If we don't know this MAC address yet, store it */
-
- if(!subnet || subnet->owner != myself) {
- 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]);
-
- 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 = node->data;
- if(c->status.active)
- send_add_subnet(c, subnet);
- }
- }
-
- 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) {
- next = node->next;
- s = node->data;
- if(s->type == SUBNET_MAC && s->net.mac.lastseen && s->net.mac.lastseen + macexpire < now) {
- 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 = node2->data;
- if(c->status.active)
- send_del_subnet(c, s);
- }
-
- subnet_del(myself, s);
- }
}
}
-static node_t *route_mac(vpn_packet_t *packet)
-{
- subnet_t *subnet;
-
- cp();
-
- /* Learn source address */
+void route(meshlink_handle_t *mesh, node_t *source, vpn_packet_t *packet) {
+ assert(source);
- learn_mac((mac_t *)(&packet->data[6]));
+ // TODO: route on name or key
- /* Lookup destination address */
+ meshlink_packethdr_t *hdr = (meshlink_packethdr_t *) packet->data;
+ node_t *dest = lookup_node(mesh, (char *)hdr->destination);
+ logger(mesh, MESHLINK_DEBUG, "Routing packet from \"%s\" to \"%s\"\n", hdr->source, hdr->destination);
- subnet = lookup_subnet_mac((mac_t *)(&packet->data[0]));
-
- if(subnet)
- return subnet->owner;
- else
- return NULL;
-}
-
-/* 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())
+ //Check Length
+ if(!checklength(source, packet, sizeof(*hdr))) {
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;
-
- cp();
-
- if(priorityinheritance)
- packet->priority = packet->data[15];
-
- subnet = lookup_subnet_ipv4((ipv4_t *) &packet->data[30]);
-
- if(!subnet) {
- 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;
-}
-
-/* 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())
+ if(dest == NULL) {
+ //Lookup failed
+ logger(mesh, MESHLINK_WARNING, "Can't lookup the destination of a packet in the route() function. This should never happen!\n");
+ logger(mesh, MESHLINK_WARNING, "Destination was: %s\n", hdr->destination);
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]);
-
- if(!subnet) {
- 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;
-}
-
-/* RFC 2461 */
-
-static void route_neighborsol(vpn_packet_t *packet)
-{
- struct ip6_hdr *hdr;
- struct nd_neighbor_solicit *ns;
- struct nd_opt_hdr *opt;
- subnet_t *subnet;
- 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();
-
- 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 */
+ if(dest == mesh->self) {
+ const void *payload = packet->data + sizeof(*hdr);
+ size_t len = packet->len - sizeof(*hdr);
- if(overwrite_mac)
- memcpy(mymac.x, packet->data + 6, 6);
+ char hex[len * 2 + 1];
- /* 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) {
- ifdebug(TRAFFIC) logger(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.next = htonl(IPPROTO_ICMPV6);
-
- /* Generate checksum */
-
- checksum = inet_checksum(&pseudo, sizeof(pseudo), ~0);
- checksum = inet_checksum(ns, sizeof(*ns) + 8, checksum);
-
- if(checksum) {
- 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);
-
- if(!subnet) {
- 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;
- }
-
- /* 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.next = htonl(IPPROTO_ICMPV6);
-
- /* Generate checksum */
-
- checksum = inet_checksum(&pseudo, sizeof(pseudo), ~0);
- checksum = inet_checksum(ns, sizeof(*ns) + 8, checksum);
-
- ns->nd_ns_hdr.icmp6_cksum = checksum;
-
- write_packet(packet);
-}
-
-/* RFC 826 */
-
-static void route_arp(vpn_packet_t *packet)
-{
- struct ether_arp *arp;
- subnet_t *subnet;
- uint8_t ipbuf[4];
-
- cp();
-
- /* First, snatch the source address from the ARP packet */
-
- 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).
- Most of the code here is taken from choparp.c by Takamichi Tateoka (tree@mma.club.uec.ac.jp)
- */
+ if(mesh->log_level <= MESHLINK_DEBUG) {
+ bin2hex(payload, hex, len); // don't do this unless it's going to be logged
+ }
- arp = (struct ether_arp *)(packet->data + 14);
+ logger(mesh, MESHLINK_DEBUG, "I received a packet for me with payload: %s\n", hex);
- /* Check if this is a valid ARP request */
+ if(mesh->receive_cb) {
+ mesh->receive_cb(mesh, (meshlink_node_t *)source, payload, len);
+ }
- 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) {
- ifdebug(TRAFFIC) logger(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) {
- 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]);
+ if(!dest->status.reachable) {
+ //TODO: check what to do here, not just print a warning
+ logger(mesh, MESHLINK_WARNING, "The destination of a packet in the route() function is unreachable. Dropping packet.\n");
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);
-}
-
-void route_outgoing(vpn_packet_t *packet)
-{
- uint16_t type;
- node_t *n = NULL;
-
- cp();
-
- if(packet->len < 64) {
- ifdebug(TRAFFIC) logger(LOG_WARNING, _("Read too short packet"));
+ if(dest == source) {
+ logger(mesh, MESHLINK_ERROR, "Routing loop for packet from %s!", source->name);
return;
}
- /* FIXME: multicast? */
-
- switch (routing_mode) {
- case RMODE_ROUTER:
- type = ntohs(*((uint16_t *)(&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:
- ifdebug(TRAFFIC) logger(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)
-{
- if(packet->len < 64) {
- ifdebug(TRAFFIC) logger(LOG_WARNING, _("Got too short packet from %s (%s)"),
- source->name, source->hostname);
- return;
- }
-
- switch (routing_mode) {
- case RMODE_ROUTER:
- {
- node_t *n = NULL;
- uint16_t type;
-
- type = ntohs(*((uint16_t *)(&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) {
- if(overwrite_mac)
- memcpy(packet->data, mymac.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;
- }
+ send_packet(mesh, dest, packet);
+ return;
}
projects / meshlink / blobdiff