/*
route.c -- routing
- Copyright (C) 2000-2005 Ivo Timmermans,
- 2000-2009 Guus Sliepen <guus@tinc-vpn.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
#include "system.h"
-#include "splay_tree.h"
-#include "connection.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}};
+static bool checklength(node_t *source, vpn_packet_t *packet, uint16_t length) {
+ assert(length);
-/* Sizes of various headers */
-
-static const size_t ether_size = sizeof(struct ether_header);
-static const size_t arp_size = sizeof(struct ether_arp);
-static const size_t ip_size = sizeof(struct ip);
-static const size_t icmp_size = sizeof(struct icmp) - sizeof(struct ip);
-static const size_t ip6_size = sizeof(struct ip6_hdr);
-static const size_t icmp6_size = sizeof(struct icmp6_hdr);
-static const size_t ns_size = sizeof(struct nd_neighbor_solicit);
-static const size_t opt_size = sizeof(struct nd_opt_hdr);
-
-static struct event age_subnets_event;
-
-/* 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 += *(uint8_t *)p;
-
- while(checksum >> 16)
- checksum = (checksum & 0xFFFF) + (checksum >> 16);
-
- return ~checksum;
-}
-
-static bool ratelimit(int frequency) {
- static time_t lasttime = 0;
- static int count = 0;
- time_t now = time(NULL);
-
- if(lasttime == now) {
- if(++count > frequency)
- return true;
- } else {
- lasttime = now;
- count = 0;
- }
-
- return false;
-}
-
-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);
+ logger(source->mesh, MESHLINK_WARNING, "Got too short packet from %s", source->name);
return false;
- } else
- return true;
-}
-
-static void swap_mac_addresses(vpn_packet_t *packet) {
- mac_t tmp;
- memcpy(&tmp, &packet->data[0], sizeof tmp);
- memcpy(&packet->data[0], &packet->data[6], sizeof tmp);
- memcpy(&packet->data[6], &tmp, sizeof tmp);
-}
-
-static void age_subnets(int fd, short events, void *data) {
- subnet_t *s;
- connection_t *c;
- splay_node_t *node, *next, *node2;
- bool left = false;
- time_t now = time(NULL);
-
- for(node = myself->subnet_tree->head; node; node = next) {
- next = node->next;
- s = node->data;
- if(s->expires && s->expires < now) {
- ifdebug(TRAFFIC) {
- char netstr[MAXNETSTR];
- if(net2str(netstr, sizeof netstr, s))
- logger(LOG_INFO, "Subnet %s expired", netstr);
- }
-
- 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);
- } else {
- if(s->expires)
- left = true;
- }
- }
-
- if(left)
- event_add(&age_subnets_event, &(struct timeval){10, 0});
-}
-
-static void learn_mac(mac_t *address) {
- subnet_t *subnet;
- splay_node_t *node;
- connection_t *c;
-
- subnet = lookup_subnet_mac(myself, address);
-
- /* If we don't know this MAC address yet, store it */
-
- if(!subnet) {
- 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;
- subnet->expires = time(NULL) + macexpire;
- subnet->net.mac.address = *address;
- subnet->weight = 10;
- 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);
- }
-
- if(!timeout_initialized(&age_subnets_event))
- timeout_set(&age_subnets_event, age_subnets, NULL);
- event_add(&age_subnets_event, &(struct timeval){10, 0});
} else {
- if(subnet->expires)
- subnet->expires = time(NULL) + macexpire;
+ return true;
}
}
-/* RFC 792 */
-
-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};
-
- struct in_addr ip_src;
- struct in_addr ip_dst;
- uint32_t oldlen;
-
- if(ratelimit(3))
- return;
-
- /* Swap Ethernet source and destination addresses */
-
- swap_mac_addresses(packet);
-
- /* Copy headers from packet into properly aligned structs on the stack */
-
- memcpy(&ip, packet->data + ether_size, ip_size);
-
- /* Remember original source and destination */
-
- ip_src = ip.ip_src;
- ip_dst = ip.ip_dst;
-
- 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;
-
- /* Copy first part of original contents to ICMP message */
-
- memmove(packet->data + ether_size + ip_size + icmp_size, packet->data + ether_size, oldlen);
-
- /* Fill in IPv4 header */
-
- ip.ip_v = 4;
- ip.ip_hl = ip_size / 4;
- ip.ip_tos = 0;
- ip.ip_len = htons(ip_size + icmp_size + oldlen);
- ip.ip_id = 0;
- ip.ip_off = 0;
- ip.ip_ttl = 255;
- ip.ip_p = IPPROTO_ICMP;
- ip.ip_sum = 0;
- ip.ip_src = ip_dst;
- ip.ip_dst = ip_src;
-
- ip.ip_sum = inet_checksum(&ip, ip_size, ~0);
-
- /* Fill in ICMP header */
-
- icmp.icmp_type = type;
- icmp.icmp_code = code;
- icmp.icmp_cksum = 0;
-
- icmp.icmp_cksum = inet_checksum(&icmp, icmp_size, ~0);
- icmp.icmp_cksum = inet_checksum(packet->data + ether_size + ip_size + icmp_size, oldlen, icmp.icmp_cksum);
-
- /* Copy structs on stack back to packet */
-
- memcpy(packet->data + ether_size, &ip, ip_size);
- memcpy(packet->data + ether_size + ip_size, &icmp, icmp_size);
-
- packet->len = ether_size + ip_size + icmp_size + oldlen;
-
- send_packet(source, packet);
-}
-
-/* RFC 791 */
+void route(meshlink_handle_t *mesh, node_t *source, vpn_packet_t *packet) {
+ assert(source);
-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;
-
- memcpy(&ip, packet->data + ether_size, ip_size);
- fragment.priority = packet->priority;
+ // TODO: route on name or key
- if(ip.ip_hl != ip_size / 4)
- return;
-
- todo = ntohs(ip.ip_len) - ip_size;
+ 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);
- 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);
+ //Check Length
+ if(!checklength(source, packet, sizeof(*hdr))) {
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;
-
- 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,
- dest.x[0],
- dest.x[1],
- dest.x[2],
- dest.x[3]);
-
- route_ipv4_unreachable(source, packet, ICMP_DEST_UNREACH, ICMP_NET_UNKNOWN);
- return;
- }
-
- if(subnet->owner == source) {
- ifdebug(TRAFFIC) logger(LOG_WARNING, "Packet looping back to %s (%s)!", source->name, source->hostname);
+ 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;
}
- if(!subnet->owner->status.reachable)
- route_ipv4_unreachable(source, packet, ICMP_DEST_UNREACH, ICMP_NET_UNREACH);
+ if(dest == mesh->self) {
+ const void *payload = packet->data + sizeof(*hdr);
+ size_t len = packet->len - sizeof(*hdr);
- if(priorityinheritance)
- packet->priority = packet->data[15];
+ char hex[len * 2 + 1];
- 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);
+ if(mesh->log_level <= MESHLINK_DEBUG) {
+ bin2hex(payload, hex, len); // don't do this unless it's going to be logged
}
- return;
- }
-
- send_packet(subnet->owner, packet);
-}
-
-static void route_ipv4(node_t *source, vpn_packet_t *packet) {
- if(!checklength(source, packet, ether_size + ip_size))
- return;
-
- if(((packet->data[30] & 0xf0) == 0xe0) || (
- packet->data[30] == 255 &&
- packet->data[31] == 255 &&
- packet->data[32] == 255 &&
- packet->data[33] == 255))
- broadcast_packet(source, packet);
- else
- route_ipv4_unicast(source, packet);
-}
-
-/* RFC 2463 */
-
-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};
- 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(3))
- return;
-
- /* Swap Ethernet source and destination addresses */
-
- swap_mac_addresses(packet);
-
- /* Copy headers from packet to structs on the stack */
-
- memcpy(&ip6, packet->data + ether_size, ip6_size);
-
- /* Remember original source and destination */
-
- pseudo.ip6_src = ip6.ip6_dst;
- 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;
-
- /* Copy first part of original contents to ICMP message */
-
- memmove(packet->data + ether_size + ip6_size + icmp6_size, packet->data + ether_size, pseudo.length);
-
- /* Fill in IPv6 header */
-
- ip6.ip6_flow = htonl(0x60000000UL);
- ip6.ip6_plen = htons(icmp6_size + pseudo.length);
- ip6.ip6_nxt = IPPROTO_ICMPV6;
- ip6.ip6_hlim = 255;
- ip6.ip6_src = pseudo.ip6_src;
- ip6.ip6_dst = pseudo.ip6_dst;
-
- /* Fill in ICMP header */
-
- icmp6.icmp6_type = type;
- icmp6.icmp6_code = code;
- icmp6.icmp6_cksum = 0;
-
- /* Create pseudo header */
-
- pseudo.length = htonl(icmp6_size + pseudo.length);
- 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 + icmp6_size, ntohl(pseudo.length) - icmp6_size, checksum);
-
- icmp6.icmp6_cksum = checksum;
-
- /* Copy structs on stack back to packet */
-
- memcpy(packet->data + ether_size, &ip6, ip6_size);
- memcpy(packet->data + ether_size + ip6_size, &icmp6, icmp6_size);
-
- packet->len = ether_size + ip6_size + ntohl(pseudo.length);
-
- send_packet(source, packet);
-}
-
-static void route_ipv6_unicast(node_t *source, vpn_packet_t *packet) {
- subnet_t *subnet;
- node_t *via;
- ipv6_t dest;
-
- 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(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;
- }
+ logger(mesh, MESHLINK_DEBUG, "I received a packet for me with payload: %s\n", hex);
- if(subnet->owner == source) {
- ifdebug(TRAFFIC) logger(LOG_WARNING, "Packet looping back to %s (%s)!", source->name, source->hostname);
- return;
- }
-
- if(!subnet->owner->status.reachable)
- 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);
-}
-
-/* RFC 2461 */
-
-static void route_neighborsol(node_t *source, vpn_packet_t *packet) {
- struct ip6_hdr ip6;
- struct nd_neighbor_solicit ns;
- struct nd_opt_hdr opt;
- subnet_t *subnet;
- uint16_t checksum;
- bool has_opt;
-
- struct {
- struct in6_addr ip6_src; /* source address */
- struct in6_addr ip6_dst; /* destination address */
- uint32_t length;
- uint32_t next;
- } pseudo;
-
- if(!checklength(source, packet, ether_size + ip6_size + ns_size))
- return;
-
- has_opt = packet->len >= ether_size + ip6_size + ns_size + opt_size + ETH_ALEN;
-
- if(source != myself) {
- ifdebug(TRAFFIC) logger(LOG_WARNING, "Got neighbor solicitation request 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(&ns, packet->data + ether_size + ip6_size, ns_size);
- if(has_opt)
- memcpy(&opt, packet->data + ether_size + ip6_size + ns_size, opt_size);
-
- /* First, snatch the source address from the neighbor solicitation packet */
-
- if(overwrite_mac)
- memcpy(mymac.x, packet->data + ETH_ALEN, ETH_ALEN);
-
- /* Check if this is a valid neighbor solicitation request */
-
- if(ns.nd_ns_hdr.icmp6_type != ND_NEIGHBOR_SOLICIT ||
- (has_opt && 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 */
-
- pseudo.ip6_src = ip6.ip6_src;
- pseudo.ip6_dst = ip6.ip6_dst;
- if(has_opt)
- pseudo.length = htonl(ns_size + opt_size + ETH_ALEN);
- else
- pseudo.length = htonl(ns_size);
- pseudo.next = htonl(IPPROTO_ICMPV6);
-
- /* Generate checksum */
-
- checksum = inet_checksum(&pseudo, sizeof pseudo, ~0);
- checksum = inet_checksum(&ns, ns_size, checksum);
- if(has_opt) {
- checksum = inet_checksum(&opt, opt_size, checksum);
- checksum = inet_checksum(packet->data + ether_size + ip6_size + ns_size + opt_size, ETH_ALEN, 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 + ETH_ALEN, ETH_ALEN); /* copy destination address */
- packet->data[ETH_ALEN * 2 - 1] ^= 0xFF; /* mangle source address so it looks like it's not from us */
-
- ip6.ip6_dst = ip6.ip6_src; /* swap destination and source protocoll address */
- ip6.ip6_src = ns.nd_ns_target;
-
- if(has_opt)
- memcpy(packet->data + ether_size + ip6_size + ns_size + opt_size, packet->data + ETH_ALEN, ETH_ALEN); /* add fake source hard addr */
-
- ns.nd_ns_cksum = 0;
- ns.nd_ns_type = ND_NEIGHBOR_ADVERT;
- ns.nd_ns_reserved = htonl(0x40000000UL); /* Set solicited flag */
- opt.nd_opt_type = ND_OPT_TARGET_LINKADDR;
-
- /* Create pseudo header */
-
- pseudo.ip6_src = ip6.ip6_src;
- pseudo.ip6_dst = ip6.ip6_dst;
- if(has_opt)
- pseudo.length = htonl(ns_size + opt_size + ETH_ALEN);
- else
- pseudo.length = htonl(ns_size);
- pseudo.next = htonl(IPPROTO_ICMPV6);
-
- /* Generate checksum */
-
- checksum = inet_checksum(&pseudo, sizeof pseudo, ~0);
- checksum = inet_checksum(&ns, ns_size, checksum);
- if(has_opt) {
- checksum = inet_checksum(&opt, opt_size, checksum);
- checksum = inet_checksum(packet->data + ether_size + ip6_size + ns_size + opt_size, ETH_ALEN, checksum);
- }
-
- ns.nd_ns_hdr.icmp6_cksum = checksum;
-
- /* Copy structs on stack back to packet */
-
- memcpy(packet->data + ether_size, &ip6, ip6_size);
- memcpy(packet->data + ether_size + ip6_size, &ns, ns_size);
- if(has_opt)
- memcpy(packet->data + ether_size + ip6_size + ns_size, &opt, opt_size);
-
- send_packet(source, packet);
-}
-
-static void route_ipv6(node_t *source, vpn_packet_t *packet) {
- if(!checklength(source, packet, ether_size + ip6_size))
- return;
-
- if(packet->data[20] == IPPROTO_ICMPV6 && checklength(source, packet, ether_size + ip6_size + icmp6_size) && packet->data[54] == ND_NEIGHBOR_SOLICIT) {
- route_neighborsol(source, packet);
- return;
- }
-
- if(packet->data[38] == 255)
- broadcast_packet(source, packet);
- else
- route_ipv6_unicast(source, packet);
-}
-
-/* RFC 826 */
-
-static void route_arp(node_t *source, vpn_packet_t *packet) {
- struct ether_arp arp;
- subnet_t *subnet;
- struct in_addr addr;
-
- if(!checklength(source, packet, ether_size + arp_size))
- return;
+ if(mesh->receive_cb) {
+ mesh->receive_cb(mesh, (meshlink_node_t *)source, payload, len);
+ }
- if(source != myself) {
- ifdebug(TRAFFIC) logger(LOG_WARNING, "Got ARP request from %s (%s) while in router mode!", source->name, source->hostname);
return;
}
- /* First, snatch the source address from the ARP packet */
-
- if(overwrite_mac)
- memcpy(mymac.x, packet->data + ETH_ALEN, ETH_ALEN);
-
- /* Copy headers from packet to structs on the stack */
-
- memcpy(&arp, packet->data + ether_size, arp_size);
-
- /* Check if this is a valid ARP request */
-
- if(ntohs(arp.arp_hrd) != ARPHRD_ETHER || ntohs(arp.arp_pro) != ETH_P_IP ||
- arp.arp_hln != ETH_ALEN || arp.arp_pln != sizeof addr || ntohs(arp.arp_op) != ARPOP_REQUEST) {
- ifdebug(TRAFFIC) logger(LOG_WARNING, "Cannot route packet: received unknown type ARP request");
+ 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 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 == source) {
+ logger(mesh, MESHLINK_ERROR, "Routing loop for packet from %s!", source->name);
return;
}
- /* Check if it is for our own subnet */
-
- if(subnet->owner == myself)
- return; /* silently ignore */
-
- memcpy(packet->data, packet->data + ETH_ALEN, ETH_ALEN); /* copy destination address */
- packet->data[ETH_ALEN * 2 - 1] ^= 0xFF; /* mangle source address so it looks like it's not from us */
-
- memcpy(&addr, arp.arp_tpa, sizeof addr); /* save protocol addr */
- memcpy(arp.arp_tpa, arp.arp_spa, sizeof addr); /* swap destination and source protocol address */
- memcpy(arp.arp_spa, &addr, sizeof addr); /* ... */
-
- memcpy(arp.arp_tha, arp.arp_sha, ETH_ALEN); /* set target hard/proto addr */
- memcpy(arp.arp_sha, packet->data + ETH_ALEN, ETH_ALEN); /* add fake source hard addr */
- arp.arp_op = htons(ARPOP_REPLY);
-
- /* Copy structs on stack back to packet */
-
- memcpy(packet->data + ether_size, &arp, arp_size);
-
- send_packet(source, packet);
-}
-
-static void route_mac(node_t *source, vpn_packet_t *packet) {
- subnet_t *subnet;
- mac_t dest;
-
- /* Learn source address */
-
- if(source == myself) {
- mac_t src;
- memcpy(&src, &packet->data[6], sizeof src);
- learn_mac(&src);
- }
-
- /* Lookup destination address */
-
- memcpy(&dest, &packet->data[0], sizeof dest);
- subnet = lookup_subnet_mac(NULL, &dest);
-
- if(!subnet) {
- broadcast_packet(source, packet);
- return;
- }
-
- if(subnet->owner == source) {
- ifdebug(TRAFFIC) logger(LOG_WARNING, "Packet looping back to %s (%s)!", source->name, source->hostname);
- return;
- }
-
- // Handle packets larger than PMTU
-
- node_t *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);
- uint16_t type = packet->data[12] << 8 | packet->data[13];
- if(type == ETH_P_IP) {
- 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;
- } else if(type == ETH_P_IPV6) {
- packet->len = via->mtu;
- route_ipv6_unreachable(source, packet, ICMP6_PACKET_TOO_BIG, 0);
- return;
- }
- }
-
- send_packet(subnet->owner, packet);
-}
-
-void route(node_t *source, vpn_packet_t *packet) {
- if(!checklength(source, packet, ether_size))
- return;
-
- switch (routing_mode) {
- case RMODE_ROUTER:
- {
- uint16_t type = packet->data[12] << 8 | packet->data[13];
-
- switch (type) {
- case ETH_P_ARP:
- route_arp(source, packet);
- break;
-
- case ETH_P_IP:
- route_ipv4(source, packet);
- break;
-
- case ETH_P_IPV6:
- route_ipv6(source, packet);
- break;
-
- default:
- ifdebug(TRAFFIC) logger(LOG_WARNING, "Cannot route packet from %s (%s): unknown type %hx", source->name, source->hostname, type);
- break;
- }
- }
- break;
-
- case RMODE_SWITCH:
- route_mac(source, packet);
- break;
-
- case RMODE_HUB:
- broadcast_packet(source, packet);
- break;
- }
+ send_packet(mesh, dest, packet);
+ return;
}
projects / meshlink / blobdiff