X-Git-Url: https://www.tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Froute.c;h=d748db163d1999db9a7b938eb93c821d010004a4;hp=18d16c0a4fba969782b22228d6a0acdc90b338c0;hb=9915f2abbedb7f1aa2b9e2f81d52ddcfca60e82d;hpb=7926a156e5b118d06295228e57de0cc9de0433b4 diff --git a/src/route.c b/src/route.c index 18d16c0a..d748db16 100644 --- a/src/route.c +++ b/src/route.c @@ -1,7 +1,7 @@ /* route.c -- routing - Copyright (C) 2000-2004 Ivo Timmermans , - 2000-2004 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 @@ -22,22 +22,6 @@ #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 "ethernet.h" @@ -69,7 +53,7 @@ static const size_t opt_size = sizeof(struct nd_opt_hdr); /* RFC 1071 */ -static __inline__ uint16_t inet_checksum(void *data, int len, uint16_t prevsum) +static uint16_t inet_checksum(void *data, int len, uint16_t prevsum) { uint16_t *p = data; uint32_t checksum = prevsum ^ 0xFFFF; @@ -88,7 +72,7 @@ static __inline__ uint16_t inet_checksum(void *data, int len, uint16_t prevsum) return ~checksum; } -static __inline__ bool ratelimit(int frequency) { +static bool ratelimit(int frequency) { static time_t lasttime = 0; static int count = 0; @@ -103,15 +87,22 @@ static __inline__ bool ratelimit(int frequency) { return false; } -static __inline__ bool checklength(node_t *source, vpn_packet_t *packet, length_t length) { +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 __inline__ void learn_mac(mac_t *address) +static void learn_mac(mac_t *address) { subnet_t *subnet; avl_node_t *node; @@ -176,34 +167,6 @@ void age_subnets(void) } } -static __inline__ void route_mac(node_t *source, vpn_packet_t *packet) -{ - subnet_t *subnet; - - cp(); - - /* Learn source address */ - - if(source == myself) - learn_mac((mac_t *)(&packet->data[6])); - - /* Lookup destination address */ - - subnet = lookup_subnet_mac((mac_t *)(&packet->data[0])); - - 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; - } - - send_packet(subnet->owner, packet); -} - /* RFC 792 */ static void route_ipv4_unreachable(node_t *source, vpn_packet_t *packet, uint8_t type, uint8_t code) @@ -220,6 +183,10 @@ static void route_ipv4_unreachable(node_t *source, vpn_packet_t *packet, uint8_t 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); @@ -278,7 +245,7 @@ static void route_ipv4_unreachable(node_t *source, vpn_packet_t *packet, uint8_t /* RFC 791 */ -static __inline__ void fragment_ipv4_packet(node_t *dest, vpn_packet_t *packet) { +static void fragment_ipv4_packet(node_t *dest, vpn_packet_t *packet) { struct ip ip; vpn_packet_t fragment; int len, maxlen, todo; @@ -296,7 +263,7 @@ static __inline__ void fragment_ipv4_packet(node_t *dest, vpn_packet_t *packet) 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 (%d)"), packet->len, ether_size + ip_size + todo); + 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; } @@ -328,22 +295,24 @@ static __inline__ void fragment_ipv4_packet(node_t *dest, vpn_packet_t *packet) } } -static __inline__ void route_ipv4_unicast(node_t *source, 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(); - 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 from %s (%s): unknown IPv4 destination address %d.%d.%d.%d"), source->name, source->hostname, - packet->data[30], - packet->data[31], - packet->data[32], - packet->data[33]); + dest.x[0], + dest.x[1], + dest.x[2], + dest.x[3]); route_ipv4_unreachable(source, packet, ICMP_DEST_UNREACH, ICMP_NET_UNKNOWN); return; @@ -362,7 +331,7 @@ static __inline__ void route_ipv4_unicast(node_t *source, vpn_packet_t *packet) via = (subnet->owner->via == myself) ? subnet->owner->nexthop : subnet->owner->via; - if(packet->len > via->mtu && via != myself) { + 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; @@ -377,14 +346,21 @@ static __inline__ void route_ipv4_unicast(node_t *source, vpn_packet_t *packet) send_packet(subnet->owner, packet); } -static __inline__ void route_ipv4(node_t *source, vpn_packet_t *packet) +static void route_ipv4(node_t *source, vpn_packet_t *packet) { cp(); if(!checklength(source, packet, ether_size + ip_size)) return; - route_ipv4_unicast(source, packet); + 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 */ @@ -407,6 +383,10 @@ static void route_ipv6_unreachable(node_t *source, vpn_packet_t *packet, uint8_t 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); @@ -466,26 +446,28 @@ static void route_ipv6_unreachable(node_t *source, vpn_packet_t *packet, uint8_t send_packet(source, packet); } -static __inline__ void route_ipv6_unicast(node_t *source, 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 from %s (%s): unknown IPv6 destination address %hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx"), source->name, source->hostname, - 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])); + 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; @@ -501,7 +483,7 @@ static __inline__ void route_ipv6_unicast(node_t *source, vpn_packet_t *packet) via = (subnet->owner->via == myself) ? subnet->owner->nexthop : subnet->owner->via; - if(packet->len > via->mtu && via != myself) { + 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); @@ -520,6 +502,7 @@ static void route_neighborsol(node_t *source, vpn_packet_t *packet) struct nd_opt_hdr opt; subnet_t *subnet; uint16_t checksum; + bool has_opt; struct { struct in6_addr ip6_src; /* source address */ @@ -530,9 +513,11 @@ static void route_neighborsol(node_t *source, vpn_packet_t *packet) cp(); - if(!checklength(source, packet, ether_size + ip6_size + ns_size + opt_size + ETH_ALEN)) + 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; @@ -542,7 +527,8 @@ static void route_neighborsol(node_t *source, vpn_packet_t *packet) 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 */ @@ -552,7 +538,7 @@ static void route_neighborsol(node_t *source, 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; } @@ -561,15 +547,20 @@ static void route_neighborsol(node_t *source, vpn_packet_t *packet) pseudo.ip6_src = ip6.ip6_src; pseudo.ip6_dst = ip6.ip6_dst; - pseudo.length = htonl(ns_size + opt_size + ETH_ALEN); + 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")); @@ -607,7 +598,8 @@ static void route_neighborsol(node_t *source, vpn_packet_t *packet) 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; @@ -618,15 +610,20 @@ static void route_neighborsol(node_t *source, vpn_packet_t *packet) pseudo.ip6_src = ip6.ip6_src; pseudo.ip6_dst = ip6.ip6_dst; - pseudo.length = htonl(ns_size + opt_size + ETH_ALEN); + 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; @@ -634,12 +631,13 @@ static void route_neighborsol(node_t *source, 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 __inline__ void route_ipv6(node_t *source, vpn_packet_t *packet) +static void route_ipv6(node_t *source, vpn_packet_t *packet) { cp(); @@ -651,7 +649,10 @@ static __inline__ void route_ipv6(node_t *source, vpn_packet_t *packet) return; } - route_ipv6_unicast(source, packet); + if(packet->data[38] == 255) + broadcast_packet(source, packet); + else + route_ipv6_unicast(source, packet); } /* RFC 826 */ @@ -723,6 +724,64 @@ static void route_arp(node_t *source, vpn_packet_t *packet) send_packet(source, packet); } +static void route_mac(node_t *source, vpn_packet_t *packet) +{ + subnet_t *subnet; + mac_t dest; + + cp(); + + + /* 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; + } + + 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); + } + } 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); + + return; + } + + send_packet(subnet->owner, packet); +} + + void route(node_t *source, vpn_packet_t *packet) { cp(); @@ -733,9 +792,8 @@ void route(node_t *source, vpn_packet_t *packet) switch (routing_mode) { case RMODE_ROUTER: { - 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_ARP: route_arp(source, packet);