X-Git-Url: https://www.tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Froute.c;h=74ad9a3469d335fa13e7472c0d3c5b13ef734834;hp=7538bec517c8a70a42bf6d566d63448e8d6f5d44;hb=84531fb6e621959e06519fdbb7f2a8f7578f66bd;hpb=a227843b739d279b63adcf3736ebb03d856080c4 diff --git a/src/route.c b/src/route.c index 7538bec5..74ad9a34 100644 --- a/src/route.c +++ b/src/route.c @@ -1,7 +1,7 @@ /* route.c -- routing Copyright (C) 2000-2005 Ivo Timmermans, - 2000-2009 Guus Sliepen + 2000-2012 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 @@ -33,6 +33,10 @@ #include "utils.h" rmode_t routing_mode = RMODE_ROUTER; +fmode_t forwarding_mode = FMODE_INTERNAL; +bmode_t broadcast_mode = BMODE_MST; +bool decrement_ttl = false; +bool directonly = false; bool priorityinheritance = false; int macexpire = 600; bool overwrite_mac = false; @@ -49,6 +53,10 @@ 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); +#ifndef MAX +#define MAX(a, b) ((a) > (b) ? (a) : (b)) +#endif + /* RFC 1071 */ static uint16_t inet_checksum(void *data, int len, uint16_t prevsum) { @@ -74,24 +82,97 @@ static bool ratelimit(int frequency) { static int count = 0; if(lasttime == now) { - if(++count > frequency) + if(count >= frequency) return true; } else { lasttime = now; count = 0; } + count++; 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); + ifdebug(TRAFFIC) logger(LOG_WARNING, "Got too short packet from %s (%s)", source->name, source->hostname); return false; } else return true; } +static void clamp_mss(const node_t *source, const node_t *via, vpn_packet_t *packet) { + if(!source || !via || !(via->options & OPTION_CLAMP_MSS)) + return; + + uint16_t mtu = source->mtu; + if(via != myself && via->mtu < mtu) + mtu = via->mtu; + + /* Find TCP header */ + int start = 0; + uint16_t type = packet->data[12] << 8 | packet->data[13]; + + if(type == ETH_P_IP && packet->data[23] == 6) + start = 14 + (packet->data[14] & 0xf) * 4; + else if(type == ETH_P_IPV6 && packet->data[20] == 6) + start = 14 + 40; + + if(!start || packet->len <= start + 20) + return; + + /* Use data offset field to calculate length of options field */ + int len = ((packet->data[start + 12] >> 4) - 5) * 4; + + if(packet->len < start + 20 + len) + return; + + /* Search for MSS option header */ + for(int i = 0; i < len;) { + if(packet->data[start + 20 + i] == 0) + break; + + if(packet->data[start + 20 + i] == 1) { + i++; + continue; + } + + if(i > len - 2 || i > len - packet->data[start + 21 + i]) + break; + + if(packet->data[start + 20 + i] != 2) { + if(packet->data[start + 21 + i] < 2) + break; + i += packet->data[start + 21 + i]; + continue; + } + + if(packet->data[start + 21] != 4) + break; + + /* Found it */ + uint16_t oldmss = packet->data[start + 22 + i] << 8 | packet->data[start + 23 + i]; + uint16_t newmss = mtu - start - 20; + uint16_t csum = packet->data[start + 16] << 8 | packet->data[start + 17]; + + if(oldmss <= newmss) + break; + + ifdebug(TRAFFIC) logger(LOG_INFO, "Clamping MSS of packet from %s to %s to %d", source->name, via->name, newmss); + + /* Update the MSS value and the checksum */ + packet->data[start + 22 + i] = newmss >> 8; + packet->data[start + 23 + i] = newmss & 0xff; + csum ^= 0xffff; + csum -= oldmss; + csum += newmss; + csum ^= 0xffff; + packet->data[start + 16] = csum >> 8; + packet->data[start + 17] = csum & 0xff; + break; + } +} + static void swap_mac_addresses(vpn_packet_t *packet) { mac_t tmp; memcpy(&tmp, &packet->data[0], sizeof tmp); @@ -104,12 +185,12 @@ static void learn_mac(mac_t *address) { avl_node_t *node; connection_t *c; - subnet = lookup_subnet_mac(address); + 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"), + 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]); @@ -117,7 +198,9 @@ static void learn_mac(mac_t *address) { subnet->type = SUBNET_MAC; subnet->expires = now + macexpire; subnet->net.mac.address = *address; + subnet->weight = 10; subnet_add(myself, subnet); + subnet_update(myself, subnet, true); /* And tell all other tinc daemons it's our MAC */ @@ -140,11 +223,11 @@ void age_subnets(void) { for(node = myself->subnet_tree->head; node; node = next) { next = node->next; s = node->data; - if(s->expires && s->expires < now) { + if(s->expires && s->expires <= now) { ifdebug(TRAFFIC) { char netstr[MAXNETSTR]; if(net2str(netstr, sizeof netstr, s)) - logger(LOG_INFO, _("Subnet %s expired"), netstr); + logger(LOG_INFO, "Subnet %s expired", netstr); } for(node2 = connection_tree->head; node2; node2 = node2->next) { @@ -153,6 +236,7 @@ void age_subnets(void) { send_del_subnet(c, s); } + subnet_update(myself, s, false); subnet_del(myself, s); } } @@ -249,11 +333,11 @@ static 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 (%zd)"), 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; } - ifdebug(TRAFFIC) logger(LOG_INFO, _("Fragmenting packet of %d bytes to %s (%s)"), packet->len, dest->name, dest->hostname); + 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; @@ -290,7 +374,7 @@ static void route_ipv4_unicast(node_t *source, vpn_packet_t *packet) { 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"), + 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], @@ -302,22 +386,33 @@ static void route_ipv4_unicast(node_t *source, vpn_packet_t *packet) { } if(subnet->owner == source) { - ifdebug(TRAFFIC) logger(LOG_WARNING, _("Packet looping back to %s (%s)!"), source->name, source->hostname); + ifdebug(TRAFFIC) logger(LOG_WARNING, "Packet looping back to %s (%s)!", source->name, source->hostname); return; } if(!subnet->owner->status.reachable) - route_ipv4_unreachable(source, packet, ICMP_DEST_UNREACH, ICMP_NET_UNREACH); + return route_ipv4_unreachable(source, packet, ICMP_DEST_UNREACH, ICMP_NET_UNREACH); + + if(forwarding_mode == FMODE_OFF && source != myself && subnet->owner != myself) + return route_ipv4_unreachable(source, packet, ICMP_DEST_UNREACH, ICMP_NET_ANO); if(priorityinheritance) packet->priority = packet->data[15]; via = (subnet->owner->via == myself) ? subnet->owner->nexthop : subnet->owner->via; + + if(via == source) { + ifdebug(TRAFFIC) logger(LOG_ERR, "Routing loop for packet from %s (%s)!", source->name, source->hostname); + return; + } - 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(directonly && subnet->owner != via) + return route_ipv4_unreachable(source, packet, ICMP_DEST_UNREACH, ICMP_NET_ANO); + + if(via && packet->len > MAX(via->mtu, 590) && 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; + packet->len = MAX(via->mtu, 590); route_ipv4_unreachable(source, packet, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED); } else { fragment_ipv4_packet(via, packet); @@ -326,6 +421,8 @@ static void route_ipv4_unicast(node_t *source, vpn_packet_t *packet) { return; } + clamp_mss(source, via, packet); + send_packet(subnet->owner, packet); } @@ -333,11 +430,11 @@ 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) || ( + if(broadcast_mode && (((packet->data[30] & 0xf0) == 0xe0) || ( packet->data[30] == 255 && packet->data[31] == 255 && packet->data[32] == 255 && - packet->data[33] == 255)) + packet->data[33] == 255))) broadcast_packet(source, packet); else route_ipv4_unicast(source, packet); @@ -432,7 +529,7 @@ static void route_ipv6_unicast(node_t *source, vpn_packet_t *packet) { 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"), + 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]), @@ -448,22 +545,35 @@ static void route_ipv6_unicast(node_t *source, vpn_packet_t *packet) { } if(subnet->owner == source) { - ifdebug(TRAFFIC) logger(LOG_WARNING, _("Packet looping back to %s (%s)!"), source->name, source->hostname); + 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); + return route_ipv6_unreachable(source, packet, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOROUTE); + + if(forwarding_mode == FMODE_OFF && source != myself && subnet->owner != myself) + return route_ipv6_unreachable(source, packet, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_ADMIN); 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; + if(via == source) { + ifdebug(TRAFFIC) logger(LOG_ERR, "Routing loop for packet from %s (%s)!", source->name, source->hostname); + return; + } + + if(directonly && subnet->owner != via) + return route_ipv6_unreachable(source, packet, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_ADMIN); + + if(via && packet->len > MAX(via->mtu, 1294) && 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 = MAX(via->mtu, 1294); route_ipv6_unreachable(source, packet, ICMP6_PACKET_TOO_BIG, 0); return; } + clamp_mss(source, via, packet); + send_packet(subnet->owner, packet); } @@ -490,7 +600,7 @@ static void route_neighborsol(node_t *source, vpn_packet_t *packet) { 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); + ifdebug(TRAFFIC) logger(LOG_WARNING, "Got neighbor solicitation request from %s (%s) while in router mode!", source->name, source->hostname); return; } @@ -510,7 +620,7 @@ static void route_neighborsol(node_t *source, vpn_packet_t *packet) { 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")); + ifdebug(TRAFFIC) logger(LOG_WARNING, "Cannot route packet: received unknown type neighbor solicitation request"); return; } @@ -534,7 +644,7 @@ static void route_neighborsol(node_t *source, vpn_packet_t *packet) { } if(checksum) { - ifdebug(TRAFFIC) logger(LOG_WARNING, _("Cannot route packet: checksum error for neighbor solicitation request")); + ifdebug(TRAFFIC) logger(LOG_WARNING, "Cannot route packet: checksum error for neighbor solicitation request"); return; } @@ -543,7 +653,7 @@ static void route_neighborsol(node_t *source, vpn_packet_t *packet) { 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"), + 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]), @@ -617,7 +727,7 @@ static void route_ipv6(node_t *source, vpn_packet_t *packet) { return; } - if(packet->data[38] == 255) + if(broadcast_mode && packet->data[38] == 255) broadcast_packet(source, packet); else route_ipv6_unicast(source, packet); @@ -634,7 +744,7 @@ static void route_arp(node_t *source, vpn_packet_t *packet) { return; if(source != myself) { - ifdebug(TRAFFIC) logger(LOG_WARNING, _("Got ARP request from %s (%s) while in router mode!"), source->name, source->hostname); + ifdebug(TRAFFIC) logger(LOG_WARNING, "Got ARP request from %s (%s) while in router mode!", source->name, source->hostname); return; } @@ -651,7 +761,7 @@ static void route_arp(node_t *source, vpn_packet_t *packet) { 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")); + ifdebug(TRAFFIC) logger(LOG_WARNING, "Cannot route packet: received unknown type ARP request"); return; } @@ -660,7 +770,7 @@ static void route_arp(node_t *source, vpn_packet_t *packet) { 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"), + 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]); return; @@ -704,7 +814,7 @@ static void route_mac(node_t *source, vpn_packet_t *packet) { /* Lookup destination address */ memcpy(&dest, &packet->data[0], sizeof dest); - subnet = lookup_subnet_mac(&dest); + subnet = lookup_subnet_mac(NULL, &dest); if(!subnet) { broadcast_packet(source, packet); @@ -712,18 +822,24 @@ static void route_mac(node_t *source, vpn_packet_t *packet) { } if(subnet->owner == source) { - ifdebug(TRAFFIC) logger(LOG_WARNING, _("Packet looping back to %s (%s)!"), source->name, source->hostname); + ifdebug(TRAFFIC) logger(LOG_WARNING, "Packet looping back to %s (%s)!", source->name, source->hostname); return; } + if(forwarding_mode == FMODE_OFF && source != myself && subnet->owner != myself) + return; + // Handle packets larger than PMTU node_t *via = (subnet->owner->via == myself) ? subnet->owner->nexthop : subnet->owner->via; + + if(directonly && subnet->owner != via) + return; 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); + 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(type == ETH_P_IP && packet->len > 590) { if(packet->data[20] & 0x40) { packet->len = via->mtu; route_ipv4_unreachable(source, packet, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED); @@ -731,20 +847,77 @@ static void route_mac(node_t *source, vpn_packet_t *packet) { fragment_ipv4_packet(via, packet); } return; - } else if(type == ETH_P_IPV6) { + } else if(type == ETH_P_IPV6 && packet->len > 1294) { packet->len = via->mtu; route_ipv6_unreachable(source, packet, ICMP6_PACKET_TOO_BIG, 0); return; } } + clamp_mss(source, via, packet); + send_packet(subnet->owner, packet); } +static bool do_decrement_ttl(node_t *source, vpn_packet_t *packet) { + uint16_t type = packet->data[12] << 8 | packet->data[13]; + + switch (type) { + case ETH_P_IP: + if(!checklength(source, packet, 14 + 32)) + return false; + + if(packet->data[22] < 1) { + if(packet->data[25] != IPPROTO_ICMP || packet->data[46] != ICMP_TIME_EXCEEDED) + route_ipv4_unreachable(source, packet, ICMP_TIME_EXCEEDED, ICMP_EXC_TTL); + return false; + } + + uint16_t old = packet->data[22] << 8 | packet->data[23]; + packet->data[22]--; + uint16_t new = packet->data[22] << 8 | packet->data[23]; + + uint32_t checksum = packet->data[24] << 8 | packet->data[25]; + checksum += old + (~new & 0xFFFF); + while(checksum >> 16) + checksum = (checksum & 0xFFFF) + (checksum >> 16); + packet->data[24] = checksum >> 8; + packet->data[25] = checksum & 0xff; + + return true; + + case ETH_P_IPV6: + if(!checklength(source, packet, 14 + 40)) + return false; + + if(packet->data[21] < 1) { + if(packet->data[20] != IPPROTO_ICMPV6 || packet->data[54] != ICMP6_TIME_EXCEEDED) + route_ipv6_unreachable(source, packet, ICMP6_TIME_EXCEEDED, ICMP6_TIME_EXCEED_TRANSIT); + return false; + } + + packet->data[21]--; + + return true; + + default: + return true; + } +} + void route(node_t *source, vpn_packet_t *packet) { + if(forwarding_mode == FMODE_KERNEL && source != myself) { + send_packet(myself, packet); + return; + } + if(!checklength(source, packet, ether_size)) return; + if(decrement_ttl && source != myself) + if(!do_decrement_ttl(source, packet)) + return; + switch (routing_mode) { case RMODE_ROUTER: { @@ -764,7 +937,7 @@ void route(node_t *source, vpn_packet_t *packet) { break; default: - ifdebug(TRAFFIC) logger(LOG_WARNING, _("Cannot route packet from %s (%s): unknown type %hx"), source->name, source->hostname, type); + ifdebug(TRAFFIC) logger(LOG_WARNING, "Cannot route packet from %s (%s): unknown type %hx", source->name, source->hostname, type); break; } }