X-Git-Url: https://www.tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Froute.c;h=d748db163d1999db9a7b938eb93c821d010004a4;hp=b586157d760de0d965cce1be211a9baae53f50d4;hb=9915f2abbedb7f1aa2b9e2f81d52ddcfca60e82d;hpb=354b7ab20e04736b368985a9e9dfd54ff5b7584e diff --git a/src/route.c b/src/route.c index b586157d..d748db16 100644 --- a/src/route.c +++ b/src/route.c @@ -1,7 +1,7 @@ /* route.c -- routing - Copyright (C) 2000-2003 Ivo Timmermans , - 2000-2003 Guus Sliepen + Copyright (C) 2000-2005 Ivo Timmermans, + 2000-2009 Guus Sliepen 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 @@ -17,30 +17,13 @@ along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. - $Id: route.c,v 1.1.2.69 2003/12/08 12:00:40 guus Exp $ + $Id$ */ #include "system.h" -#ifdef HAVE_NET_ETHERNET_H -#include -#endif -#ifdef HAVE_NET_IF_ARP_H -#include -#endif -#ifdef HAVE_NETINET_IP_ICMP_H -#include -#endif -#ifdef HAVE_NETINET_ICMP6_H -#include -#endif -#ifdef HAVE_NETINET_IF_ETHER_H -#include -#endif - #include "avl_tree.h" #include "connection.h" -#include "device.h" #include "ethernet.h" #include "ipv4.h" #include "ipv6.h" @@ -81,7 +64,7 @@ static uint16_t inet_checksum(void *data, int len, uint16_t prevsum) } if(len) - checksum += *(unsigned char *)p; + checksum += *(uint8_t *)p; while(checksum >> 16) checksum = (checksum & 0xFFFF) + (checksum >> 16); @@ -103,6 +86,21 @@ static bool ratelimit(int frequency) { 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); + 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 learn_mac(mac_t *address) { @@ -116,14 +114,15 @@ static void learn_mac(mac_t *address) /* If we don't know this MAC address yet, store it */ - if(!subnet || subnet->owner != myself) { + 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; - memcpy(&subnet->net.mac.address, address, sizeof(mac_t)); + subnet->expires = now + macexpire; + subnet->net.mac.address = *address; subnet_add(myself, subnet); /* And tell all other tinc daemons it's our MAC */ @@ -135,10 +134,11 @@ static void learn_mac(mac_t *address) } } - subnet->net.mac.lastseen = now; + if(subnet->expires) + subnet->expires = now + macexpire; } -void age_mac(void) +void age_subnets(void) { subnet_t *s; connection_t *c; @@ -149,11 +149,12 @@ void age_mac(void) 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]); + 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; @@ -166,32 +167,12 @@ void age_mac(void) } } -static node_t *route_mac(vpn_packet_t *packet) -{ - subnet_t *subnet; - - cp(); - - /* 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; -} - /* RFC 792 */ -static void route_ipv4_unreachable(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; - struct icmp icmp; + struct ip ip = {0}; + struct icmp icmp = {0}; struct in_addr ip_src; struct in_addr ip_dst; @@ -202,18 +183,24 @@ static void route_ipv4_unreachable(vpn_packet_t *packet, uint8_t code) cp(); + /* 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); - memcpy(&icmp, packet->data + ether_size + ip_size, icmp_size); /* Remember original source and destination */ - - memcpy(&ip_src, &ip.ip_src, sizeof(ip_src)); - memcpy(&ip_dst, &ip.ip_dst, sizeof(ip_dst)); + + 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; @@ -232,14 +219,14 @@ static void route_ipv4_unreachable(vpn_packet_t *packet, uint8_t code) ip.ip_ttl = 255; ip.ip_p = IPPROTO_ICMP; ip.ip_sum = 0; - memcpy(&ip.ip_src, &ip_dst, sizeof(ip_src)); - memcpy(&ip.ip_dst, &ip_src, sizeof(ip_dst)); + 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 = ICMP_DEST_UNREACH; + icmp.icmp_type = type; icmp.icmp_code = code; icmp.icmp_cksum = 0; @@ -252,42 +239,136 @@ static void route_ipv4_unreachable(vpn_packet_t *packet, uint8_t code) 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 */ + +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; - write_packet(packet); + 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 node_t *route_ipv4(vpn_packet_t *packet) +static void route_ipv4_unicast(node_t *source, vpn_packet_t *packet) { subnet_t *subnet; + node_t *via; + ipv4_t dest; cp(); - if(priorityinheritance) - packet->priority = packet->data[15]; - - 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: 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; + 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); + return; + } + if(!subnet->owner->status.reachable) - route_ipv4_unreachable(packet, ICMP_NET_UNREACH); + route_ipv4_unreachable(source, packet, ICMP_DEST_UNREACH, ICMP_NET_UNREACH); - return subnet->owner; + 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 void route_ipv4(node_t *source, vpn_packet_t *packet) +{ + cp(); + + 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(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; + struct icmp6_hdr icmp6 = {0}; uint16_t checksum; struct { @@ -302,17 +383,23 @@ static void route_ipv6_unreachable(vpn_packet_t *packet, uint8_t code) cp(); + /* 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); - memcpy(&icmp6, packet->data + ether_size + ip6_size, icmp6_size); /* Remember original source and destination */ - - memcpy(&pseudo.ip6_src, &ip6.ip6_dst, sizeof(ip6.ip6_src)); - memcpy(&pseudo.ip6_dst, &ip6.ip6_src, sizeof(ip6.ip6_dst)); + + pseudo.ip6_src = ip6.ip6_dst; + pseudo.ip6_dst = ip6.ip6_src; + + pseudo.length = packet->len - ether_size; - pseudo.length = ntohs(ip6.ip6_plen) + ip6_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; @@ -327,12 +414,12 @@ static void route_ipv6_unreachable(vpn_packet_t *packet, uint8_t code) ip6.ip6_plen = htons(icmp6_size + pseudo.length); ip6.ip6_nxt = IPPROTO_ICMPV6; ip6.ip6_hlim = 255; - memcpy(&ip6.ip6_src, &pseudo.ip6_src, sizeof(ip6.ip6_src)); - memcpy(&ip6.ip6_dst, &pseudo.ip6_dst, sizeof(ip6.ip6_dst)); + ip6.ip6_src = pseudo.ip6_src; + ip6.ip6_dst = pseudo.ip6_dst; /* Fill in ICMP header */ - icmp6.icmp6_type = ICMP6_DST_UNREACH; + icmp6.icmp6_type = type; icmp6.icmp6_code = code; icmp6.icmp6_cksum = 0; @@ -356,47 +443,66 @@ static void route_ipv6_unreachable(vpn_packet_t *packet, uint8_t code) packet->len = ether_size + ip6_size + ntohl(pseudo.length); - write_packet(packet); + send_packet(source, packet); } -static node_t *route_ipv6(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: 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; + 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; + } + + 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(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; - return subnet->owner; + 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(vpn_packet_t *packet) +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 */ @@ -407,11 +513,22 @@ static void route_neighborsol(vpn_packet_t *packet) cp(); + 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); - memcpy(&opt, packet->data + ether_size + ip6_size + ns_size, opt_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 */ @@ -421,24 +538,29 @@ static void route_neighborsol(vpn_packet_t *packet) /* 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) { + (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 */ - memcpy(&pseudo.ip6_src, &ip6.ip6_src, sizeof(ip6.ip6_src)); - memcpy(&pseudo.ip6_dst, &ip6.ip6_dst, sizeof(ip6.ip6_dst)); - pseudo.length = htonl(ns_size + opt_size + ETH_ALEN); + 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); - checksum = inet_checksum(&opt, opt_size, checksum); - checksum = inet_checksum(packet->data + ether_size + ip6_size + ns_size + opt_size, ETH_ALEN, 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")); @@ -473,10 +595,11 @@ static void route_neighborsol(vpn_packet_t *packet) 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(&ip6.ip6_dst, &ip6.ip6_src, sizeof(ip6.ip6_dst)); /* ... */ - memcpy(&ip6.ip6_src, &ns.nd_ns_target, sizeof(ip6.ip6_src)); /* swap destination and source protocol address */ + ip6.ip6_dst = ip6.ip6_src; /* swap destination and source protocoll address */ + ip6.ip6_src = ns.nd_ns_target; - memcpy(packet->data + ether_size + ip6_size + ns_size + opt_size, packet->data + ETH_ALEN, ETH_ALEN); /* add fake source hard addr */ + 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; @@ -485,17 +608,22 @@ static void route_neighborsol(vpn_packet_t *packet) /* Create pseudo header */ - memcpy(&pseudo.ip6_src, &ip6.ip6_src, sizeof(ip6.ip6_src)); - memcpy(&pseudo.ip6_dst, &ip6.ip6_dst, sizeof(ip6.ip6_dst)); - pseudo.length = htonl(ns_size + opt_size + ETH_ALEN); + 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); - checksum = inet_checksum(&opt, opt_size, checksum); - checksum = inet_checksum(packet->data + ether_size + ip6_size + ns_size + opt_size, ETH_ALEN, 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; @@ -503,14 +631,33 @@ static void route_neighborsol(vpn_packet_t *packet) memcpy(packet->data + ether_size, &ip6, ip6_size); memcpy(packet->data + ether_size + ip6_size, &ns, ns_size); - memcpy(packet->data + ether_size + ip6_size + ns_size, &opt, opt_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) +{ + cp(); + + 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; + } - write_packet(packet); + if(packet->data[38] == 255) + broadcast_packet(source, packet); + else + route_ipv6_unicast(source, packet); } /* RFC 826 */ -static void route_arp(vpn_packet_t *packet) +static void route_arp(node_t *source, vpn_packet_t *packet) { struct ether_arp arp; subnet_t *subnet; @@ -518,6 +665,14 @@ static void route_arp(vpn_packet_t *packet) cp(); + if(!checklength(source, packet, ether_size + arp_size)) + return; + + 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) @@ -566,150 +721,105 @@ static void route_arp(vpn_packet_t *packet) memcpy(packet->data + ether_size, &arp, arp_size); - write_packet(packet); + send_packet(source, packet); } -void route_outgoing(vpn_packet_t *packet) +static void route_mac(node_t *source, vpn_packet_t *packet) { - uint16_t type; - node_t *n = NULL; + subnet_t *subnet; + mac_t dest; cp(); - if(packet->len < ether_size) { - ifdebug(TRAFFIC) logger(LOG_WARNING, _("Read too short packet")); + + /* 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(&dest); + + if(!subnet) { + broadcast_packet(source, packet); return; } - /* FIXME: multicast? */ + if(subnet->owner == source) { + ifdebug(TRAFFIC) logger(LOG_WARNING, _("Packet looping back to %s (%s)!"), source->name, source->hostname); + return; + } - switch (routing_mode) { - case RMODE_ROUTER: - type = ntohs(*((uint16_t *)(&packet->data[12]))); - switch (type) { - case ETH_P_IP: - if(packet->len < ether_size + ip_size) { - ifdebug(TRAFFIC) logger(LOG_WARNING, _("Read too short packet")); - return; - } - - n = route_ipv4(packet); - break; - - case ETH_P_IPV6: - if(packet->len < ether_size + ip6_size) { - ifdebug(TRAFFIC) logger(LOG_WARNING, _("Read too short packet")); - return; - } - - if(packet->data[20] == IPPROTO_ICMPV6 && packet->len >= ether_size + ip6_size + ns_size && packet->data[54] == ND_NEIGHBOR_SOLICIT) { - route_neighborsol(packet); - return; - } - n = route_ipv6(packet); - break; - - case ETH_P_ARP: - if(packet->len < ether_size + arp_size) { - ifdebug(TRAFFIC) logger(LOG_WARNING, _("Read too short packet")); - return; - } - - 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; + // Handle packets larger than PMTU - case RMODE_SWITCH: - n = route_mac(packet); - if(n) - send_packet(n, packet); - else - broadcast_packet(myself, packet); - break; + 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); + } + } else if(type == ETH_P_IPV6) { + packet->len = via->mtu; + route_ipv6_unreachable(source, packet, ICMP6_PACKET_TOO_BIG, 0); + } else + ifdebug(TRAFFIC) logger(LOG_INFO, _("Large packet of unhandled type %hx dropped"), type); - case RMODE_HUB: - broadcast_packet(myself, packet); - break; + return; } + + send_packet(subnet->owner, packet); } -void route_incoming(node_t *source, vpn_packet_t *packet) + +void route(node_t *source, vpn_packet_t *packet) { - if(packet->len < ether_size) { - ifdebug(TRAFFIC) logger(LOG_WARNING, _("Read too short packet")); + cp(); + + if(!checklength(source, packet, ether_size)) return; - } switch (routing_mode) { case RMODE_ROUTER: { - node_t *n = NULL; - uint16_t type; + uint16_t type = packet->data[12] << 8 | packet->data[13]; - type = ntohs(*((uint16_t *)(&packet->data[12]))); switch (type) { - case ETH_P_IP: - if(packet->len < ether_size + ip_size) { - ifdebug(TRAFFIC) logger(LOG_WARNING, _("Read too short packet")); - return; - } + case ETH_P_ARP: + route_arp(source, packet); + break; - n = route_ipv4(packet); + case ETH_P_IP: + route_ipv4(source, packet); break; case ETH_P_IPV6: - if(packet->len < ether_size + ip6_size) { - ifdebug(TRAFFIC) logger(LOG_WARNING, _("Read too short packet")); - return; - } - - n = route_ipv6(packet); + route_ipv6(source, packet); break; default: - n = myself; + ifdebug(TRAFFIC) logger(LOG_WARNING, _("Cannot route packet from %s (%s): unknown type %hx"), source->name, source->hostname, type); break; } - - if(n) { - if(n == myself) { - if(overwrite_mac) - memcpy(packet->data, mymac.x, ETH_ALEN); - 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); - } - } + route_mac(source, packet); break; case RMODE_HUB: - broadcast_packet(source, packet); /* Spread it on */ - write_packet(packet); + broadcast_packet(source, packet); break; } }