X-Git-Url: http://git.meshlink.io/?a=blobdiff_plain;f=src%2Froute.c;h=8acabb1b02999b931ca5fb607e1a7335c10ef25b;hb=08aabbf9317806bc50a9a6693ca866c8936ce26b;hp=8924329bcb44607ec91af2d575e95172bc3649ca;hpb=6b12bea62fe2e4bd8b5b6bd0e5ca7f53318705db;p=meshlink diff --git a/src/route.c b/src/route.c index 8924329b..8acabb1b 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 @@ -17,28 +17,12 @@ along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. - $Id: route.c,v 1.1.2.72 2003/12/20 19:47:53 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 "splay_tree.h" #include "connection.h" #include "ethernet.h" #include "ipv4.h" @@ -67,9 +51,11 @@ 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 __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; @@ -88,9 +74,10 @@ 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; + time_t now = time(NULL); if(lasttime == now) { if(++count > frequency) @@ -103,7 +90,7 @@ 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; @@ -111,10 +98,47 @@ static __inline__ bool checklength(node_t *source, vpn_packet_t *packet, length_ return true; } -static __inline__ void learn_mac(mac_t *address) +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); + + cp(); + + 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; - avl_node_t *node; + splay_node_t *node; connection_t *c; cp(); @@ -130,7 +154,7 @@ static __inline__ void learn_mac(mac_t *address) subnet = new_subnet(); subnet->type = SUBNET_MAC; - subnet->expires = now + macexpire; + subnet->expires = time(NULL) + macexpire; subnet->net.mac.address = *address; subnet_add(myself, subnet); @@ -141,55 +165,36 @@ static __inline__ void learn_mac(mac_t *address) if(c->status.active) send_add_subnet(c, subnet); } - } - - if(subnet->expires) - subnet->expires = now + macexpire; -} - -void age_subnets(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->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); - } + 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; } } -static __inline__ void route_mac(node_t *source, vpn_packet_t *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) - learn_mac((mac_t *)(&packet->data[6])); + if(source == myself) { + mac_t src; + memcpy(&src, &packet->data[6], sizeof src); + learn_mac(&src); + } /* Lookup destination address */ - subnet = lookup_subnet_mac((mac_t *)(&packet->data[0])); + memcpy(&dest, &packet->data[0], sizeof dest); + subnet = lookup_subnet_mac(&dest); if(!subnet) { broadcast_packet(source, packet); @@ -276,21 +281,76 @@ static void route_ipv4_unreachable(node_t *source, vpn_packet_t *packet, uint8_t send_packet(source, packet); } -static __inline__ void route_ipv4_unicast(node_t *source, vpn_packet_t *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; + + 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; 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; @@ -304,27 +364,41 @@ static __inline__ void route_ipv4_unicast(node_t *source, vpn_packet_t *packet) if(!subnet->owner->status.reachable) route_ipv4_unreachable(source, packet, ICMP_DEST_UNREACH, ICMP_NET_UNREACH); - if(subnet->owner->options & OPTION_DONTFRAGMENT && packet->len > subnet->owner->mtu && subnet->owner != myself) { - ifdebug(TRAFFIC) logger(LOG_INFO, _("Packet for %s (%s) length %d larger than MTU %d"), subnet->owner->name, subnet->owner->hostname, packet->len, subnet->owner->mtu); - packet->len = subnet->owner->mtu; - route_ipv4_unreachable(source, packet, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED); - return; - } - 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 __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 */ @@ -390,7 +464,7 @@ static void route_ipv6_unreachable(node_t *source, vpn_packet_t *packet, uint8_t /* Generate checksum */ - checksum = inet_checksum(&pseudo, sizeof(pseudo), ~0); + 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); @@ -406,25 +480,28 @@ 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; @@ -437,10 +514,12 @@ static __inline__ void route_ipv6_unicast(node_t *source, vpn_packet_t *packet) 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(subnet->owner->options & OPTION_DONTFRAGMENT && packet->len > subnet->owner->mtu && subnet->owner != myself) { - ifdebug(TRAFFIC) logger(LOG_INFO, _("Packet for %s (%s) length %d larger than MTU %d"), subnet->owner->name, subnet->owner->hostname, packet->len, subnet->owner->mtu); - packet->len = subnet->owner->mtu; + 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; } @@ -457,6 +536,7 @@ 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 */ @@ -467,9 +547,11 @@ 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; @@ -479,7 +561,8 @@ 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 */ @@ -489,7 +572,7 @@ 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; } @@ -498,15 +581,20 @@ 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(&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")); @@ -544,7 +632,8 @@ 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; @@ -555,15 +644,20 @@ 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(&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; @@ -571,12 +665,13 @@ 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(); @@ -588,7 +683,10 @@ 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 */ @@ -621,7 +719,7 @@ static void route_arp(node_t *source, vpn_packet_t *packet) /* 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) { + 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")); return; } @@ -645,9 +743,9 @@ static void route_arp(node_t *source, 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(&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(&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 */