X-Git-Url: https://tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Froute.c;h=e9e07f67263a2d39cbe468e06ae576ea516926f6;hp=ff84ee985864ea5a25c88448d7cc788d947c49b2;hb=acbb9d6692614539260749c7b763eca5a6f81f07;hpb=6f9f6779e6bd1dd7bb795b42dad550863a386ca8 diff --git a/src/route.c b/src/route.c index ff84ee98..e9e07f67 100644 --- a/src/route.c +++ b/src/route.c @@ -1,7 +1,7 @@ /* route.c -- routing - Copyright (C) 2000-2002 Ivo Timmermans , - 2000-2002 Guus Sliepen + Copyright (C) 2000-2003 Ivo Timmermans , + 2000-2003 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 @@ -17,57 +17,78 @@ along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. - $Id: route.c,v 1.1.2.46 2002/09/09 22:33:16 guus Exp $ + $Id: route.c,v 1.1.2.66 2003/10/01 09:14:01 guus Exp $ */ -#include "config.h" +#include "system.h" -#ifdef HAVE_SYS_PARAM_H -#include -#endif -#include -#include -#ifdef HAVE_NET_IF_H -#include -#endif #ifdef HAVE_NET_ETHERNET_H #include #endif -#ifdef HAVE_NETINET_IN_SYSTM_H -#include +#ifdef HAVE_NET_IF_ARP_H +#include #endif -#include +#ifdef HAVE_NETINET_IP_ICMP_H +#include +#endif +#ifdef HAVE_NETINET_ICMP6_H #include +#endif +#ifdef HAVE_NETINET_IF_ETHER_H #include -#include -#include -#include -#include -#ifdef HAVE_INTTYPES_H -#include #endif -#include - -#include "net.h" +#include "avl_tree.h" #include "connection.h" -#include "subnet.h" -#include "route.h" -#include "protocol.h" #include "device.h" +#include "ethernet.h" +#include "ipv4.h" +#include "ipv6.h" +#include "logger.h" +#include "net.h" +#include "protocol.h" +#include "route.h" +#include "subnet.h" +#include "utils.h" -#include "system.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}}; -#ifndef ETHER_ADDR_LEN -#define ETHER_ADDR_LEN 6 -#endif +/* RFC 1071 */ -int routing_mode = RMODE_ROUTER; -int priorityinheritance = 0; -int macexpire = 600; -subnet_t mymac; +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 += *(unsigned char *)p; + + while(checksum >> 16) + checksum = (checksum & 0xFFFF) + (checksum >> 16); + + return ~checksum; +} + +static bool ratelimit(void) { + static time_t lasttime = 0; + + if(lasttime == now) + return true; -void learn_mac(mac_t *address) + lasttime = now; + return false; +} + +static void learn_mac(mac_t *address) { subnet_t *subnet; avl_node_t *node; @@ -80,8 +101,7 @@ void learn_mac(mac_t *address) /* If we don't know this MAC address yet, store it */ if(!subnet || subnet->owner != myself) { - if(debug_lvl >= DEBUG_TRAFFIC) - syslog(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]); @@ -93,7 +113,7 @@ void learn_mac(mac_t *address) /* And tell all other tinc daemons it's our MAC */ for(node = connection_tree->head; node; node = node->next) { - c = (connection_t *) node->data; + c = node->data; if(c->status.active) send_add_subnet(c, subnet); } @@ -112,16 +132,15 @@ void age_mac(void) for(node = myself->subnet_tree->head; node; node = next) { next = node->next; - s = (subnet_t *) node->data; + s = node->data; if(s->type == SUBNET_MAC && s->net.mac.lastseen && s->net.mac.lastseen + macexpire < now) { - if(debug_lvl >= DEBUG_TRAFFIC) - syslog(LOG_INFO, _("MAC address %hx:%hx:%hx:%hx:%hx:%hx expired"), + 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]); for(node2 = connection_tree->head; node2; node2 = node2->next) { - c = (connection_t *) node2->data; + c = node2->data; if(c->status.active) send_del_subnet(c, s); } @@ -131,7 +150,7 @@ void age_mac(void) } } -node_t *route_mac(vpn_packet_t *packet) +static node_t *route_mac(vpn_packet_t *packet) { subnet_t *subnet; @@ -151,7 +170,68 @@ node_t *route_mac(vpn_packet_t *packet) return NULL; } -node_t *route_ipv4(vpn_packet_t *packet) +/* RFC 792 */ + +static void route_ipv4_unreachable(vpn_packet_t *packet, uint8_t code) +{ + struct ip *hdr; + struct icmp *icmp; + + struct in_addr ip_src; + struct in_addr ip_dst; + uint32_t oldlen; + + if(ratelimit()) + return; + + cp(); + + hdr = (struct ip *)(packet->data + 14); + icmp = (struct icmp *)(packet->data + 14 + 20); + + /* Remember original source and destination */ + + memcpy(&ip_src, &hdr->ip_src, 4); + memcpy(&ip_dst, &hdr->ip_dst, 4); + oldlen = packet->len - 14; + + if(oldlen >= IP_MSS - sizeof(*hdr) - sizeof(*icmp)) + oldlen = IP_MSS - sizeof(*hdr) - sizeof(*icmp); + + /* Copy first part of original contents to ICMP message */ + + memmove(&icmp->icmp_ip, hdr, oldlen); + + /* Fill in IPv4 header */ + + hdr->ip_v = 4; + hdr->ip_hl = sizeof(*hdr) / 4; + hdr->ip_tos = 0; + hdr->ip_len = htons(20 + 8 + oldlen); + hdr->ip_id = 0; + hdr->ip_off = 0; + hdr->ip_ttl = 255; + hdr->ip_p = IPPROTO_ICMP; + hdr->ip_sum = 0; + memcpy(&hdr->ip_src, &ip_dst, 4); + memcpy(&hdr->ip_dst, &ip_src, 4); + + hdr->ip_sum = inet_checksum(hdr, 20, ~0); + + /* Fill in ICMP header */ + + icmp->icmp_type = ICMP_DEST_UNREACH; + icmp->icmp_code = code; + icmp->icmp_cksum = 0; + + icmp->icmp_cksum = inet_checksum(icmp, 8 + oldlen, ~0); + + packet->len = 14 + 20 + 8 + oldlen; + + write_packet(packet); +} + +static node_t *route_ipv4(vpn_packet_t *packet) { subnet_t *subnet; @@ -160,62 +240,123 @@ node_t *route_ipv4(vpn_packet_t *packet) if(priorityinheritance) packet->priority = packet->data[15]; - subnet = lookup_subnet_ipv4((ipv4_t *) & packet->data[30]); + subnet = lookup_subnet_ipv4((ipv4_t *) &packet->data[30]); if(!subnet) { - if(debug_lvl >= DEBUG_TRAFFIC) { - syslog(LOG_WARNING, _("Cannot route packet: unknown IPv4 destination address %d.%d.%d.%d"), + 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; } + + if(!subnet->owner->status.reachable) + route_ipv4_unreachable(packet, ICMP_NET_UNREACH); return subnet->owner; } -node_t *route_ipv6(vpn_packet_t *packet) +/* RFC 2463 */ + +static void route_ipv6_unreachable(vpn_packet_t *packet, uint8_t code) +{ + struct ip6_hdr *hdr; + struct icmp6_hdr *icmp; + 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()) + return; + + cp(); + + hdr = (struct ip6_hdr *)(packet->data + 14); + icmp = (struct icmp6_hdr *)(packet->data + 14 + sizeof(*hdr)); + + /* Remember original source and destination */ + + memcpy(&pseudo.ip6_src, &hdr->ip6_dst, 16); + memcpy(&pseudo.ip6_dst, &hdr->ip6_src, 16); + pseudo.length = ntohs(hdr->ip6_plen) + sizeof(*hdr); + + if(pseudo.length >= IP_MSS - sizeof(*hdr) - sizeof(*icmp)) + pseudo.length = IP_MSS - sizeof(*hdr) - sizeof(*icmp); + + /* Copy first part of original contents to ICMP message */ + + memmove(((char *)icmp) + sizeof(*icmp), hdr, pseudo.length); + + /* Fill in IPv6 header */ + + hdr->ip6_flow = htonl(0x60000000UL); + hdr->ip6_plen = htons(sizeof(*icmp) + pseudo.length); + hdr->ip6_nxt = IPPROTO_ICMPV6; + hdr->ip6_hlim = 255; + memcpy(&hdr->ip6_dst, &pseudo.ip6_dst, 16); + memcpy(&hdr->ip6_src, &pseudo.ip6_src, 16); + + /* Fill in ICMP header */ + + icmp->icmp6_type = ICMP6_DST_UNREACH; + icmp->icmp6_code = code; + icmp->icmp6_cksum = 0; + + /* Create pseudo header */ + + pseudo.length = htonl(sizeof(*icmp) + pseudo.length); + pseudo.next = htonl(IPPROTO_ICMPV6); + + /* Generate checksum */ + + checksum = inet_checksum(&pseudo, sizeof(pseudo), ~0); + checksum = inet_checksum(icmp, ntohl(pseudo.length), checksum); + + icmp->icmp6_cksum = checksum; + + packet->len = 14 + sizeof(*hdr) + ntohl(pseudo.length); + + write_packet(packet); +} + +static node_t *route_ipv6(vpn_packet_t *packet) { subnet_t *subnet; cp(); - subnet = lookup_subnet_ipv6((ipv6_t *) & packet->data[38]); + subnet = lookup_subnet_ipv6((ipv6_t *) &packet->data[38]); if(!subnet) { - if(debug_lvl >= DEBUG_TRAFFIC) { - syslog(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])); - } + 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; } + if(!subnet->owner->status.reachable) + route_ipv6_unreachable(packet, ICMP6_DST_UNREACH_NOROUTE); + return subnet->owner; } -uint16_t inet_checksum(uint16_t *data, int len, uint16_t prevsum) -{ - uint32_t checksum = prevsum ^ 0xFFFF; - - while(len--) - checksum += ntohs(*data++); +/* RFC 2461 */ - while(checksum >> 16) - checksum = (checksum & 0xFFFF) + (checksum >> 16); - - return checksum ^ 0xFFFF; -} - -void route_neighborsol(vpn_packet_t *packet) +static void route_neighborsol(vpn_packet_t *packet) { struct ip6_hdr *hdr; struct nd_neighbor_solicit *ns; @@ -227,7 +368,7 @@ void route_neighborsol(vpn_packet_t *packet) struct in6_addr ip6_src; /* source address */ struct in6_addr ip6_dst; /* destination address */ uint32_t length; - uint8_t junk[4]; + uint32_t next; } pseudo; cp(); @@ -238,15 +379,14 @@ void route_neighborsol(vpn_packet_t *packet) /* First, snatch the source address from the neighbor solicitation packet */ - memcpy(mymac.net.mac.address.x, packet->data + 6, 6); + if(overwrite_mac) + memcpy(mymac.x, packet->data + 6, 6); /* 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) { - if(debug_lvl > DEBUG_TRAFFIC) { - syslog(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; } @@ -255,36 +395,32 @@ void route_neighborsol(vpn_packet_t *packet) memcpy(&pseudo.ip6_src, &hdr->ip6_src, 16); memcpy(&pseudo.ip6_dst, &hdr->ip6_dst, 16); pseudo.length = htonl(sizeof(*ns) + sizeof(*opt) + 6); - pseudo.junk[0] = pseudo.junk[1] = pseudo.junk[2] = 0; - pseudo.junk[3] = IPPROTO_ICMPV6; + pseudo.next = htonl(IPPROTO_ICMPV6); /* Generate checksum */ - checksum = inet_checksum((uint16_t *) & pseudo, sizeof(pseudo) / 2, ~0); - checksum = inet_checksum((uint16_t *) ns, sizeof(*ns) / 2 + 4, checksum); + checksum = inet_checksum(&pseudo, sizeof(pseudo), ~0); + checksum = inet_checksum(ns, sizeof(*ns) + 8, checksum); if(checksum) { - if(debug_lvl >= DEBUG_TRAFFIC) - syslog(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; } /* Check if the IPv6 address exists on the VPN */ - subnet = lookup_subnet_ipv6((ipv6_t *) & ns->nd_ns_target); + subnet = lookup_subnet_ipv6((ipv6_t *) &ns->nd_ns_target); if(!subnet) { - if(debug_lvl >= DEBUG_TRAFFIC) { - syslog(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])); - } + 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; } @@ -317,20 +453,21 @@ void route_neighborsol(vpn_packet_t *packet) memcpy(&pseudo.ip6_src, &hdr->ip6_src, 16); memcpy(&pseudo.ip6_dst, &hdr->ip6_dst, 16); pseudo.length = htonl(sizeof(*ns) + sizeof(*opt) + 6); - pseudo.junk[0] = pseudo.junk[1] = pseudo.junk[2] = 0; - pseudo.junk[3] = IPPROTO_ICMPV6; + pseudo.next = htonl(IPPROTO_ICMPV6); /* Generate checksum */ - checksum = inet_checksum((uint16_t *) & pseudo, sizeof(pseudo) / 2, ~0); - checksum = inet_checksum((uint16_t *) ns, sizeof(*ns) / 2 + 4, checksum); + checksum = inet_checksum(&pseudo, sizeof(pseudo), ~0); + checksum = inet_checksum(ns, sizeof(*ns) + 8, checksum); - ns->nd_ns_hdr.icmp6_cksum = htons(checksum); + ns->nd_ns_hdr.icmp6_cksum = checksum; write_packet(packet); } -void route_arp(vpn_packet_t *packet) +/* RFC 826 */ + +static void route_arp(vpn_packet_t *packet) { struct ether_arp *arp; subnet_t *subnet; @@ -340,7 +477,8 @@ void route_arp(vpn_packet_t *packet) /* First, snatch the source address from the ARP packet */ - memcpy(mymac.net.mac.address.x, packet->data + 6, 6); + if(overwrite_mac) + memcpy(mymac.x, packet->data + 6, 6); /* This routine generates replies to ARP requests. You don't need to set NOARP flag on the interface anymore (which is broken on FreeBSD). @@ -353,9 +491,7 @@ void route_arp(vpn_packet_t *packet) if(ntohs(arp->arp_hrd) != ARPHRD_ETHER || ntohs(arp->arp_pro) != ETHERTYPE_IP || arp->arp_hln != ETHER_ADDR_LEN || arp->arp_pln != 4 || ntohs(arp->arp_op) != ARPOP_REQUEST) { - if(debug_lvl > DEBUG_TRAFFIC) { - syslog(LOG_WARNING, _("Cannot route packet: received unknown type ARP request")); - } + ifdebug(TRAFFIC) logger(LOG_WARNING, _("Cannot route packet: received unknown type ARP request")); return; } @@ -364,12 +500,9 @@ void route_arp(vpn_packet_t *packet) subnet = lookup_subnet_ipv4((ipv4_t *) arp->arp_tpa); if(!subnet) { - if(debug_lvl >= DEBUG_TRAFFIC) { - syslog(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; } @@ -399,6 +532,11 @@ void route_outgoing(vpn_packet_t *packet) cp(); + if(packet->len < 14) { + ifdebug(TRAFFIC) logger(LOG_WARNING, _("Read too short packet")); + return; + } + /* FIXME: multicast? */ switch (routing_mode) { @@ -406,11 +544,21 @@ void route_outgoing(vpn_packet_t *packet) type = ntohs(*((uint16_t *)(&packet->data[12]))); switch (type) { case 0x0800: + if(packet->len < 34) { + ifdebug(TRAFFIC) logger(LOG_WARNING, _("Read too short packet")); + return; + } + n = route_ipv4(packet); break; case 0x86DD: - if(packet->data[20] == IPPROTO_ICMPV6 && packet->data[54] == ND_NEIGHBOR_SOLICIT) { + if(packet->len < 54) { + ifdebug(TRAFFIC) logger(LOG_WARNING, _("Read too short packet")); + return; + } + + if(packet->data[20] == IPPROTO_ICMPV6 && packet->len >= 62 && packet->data[54] == ND_NEIGHBOR_SOLICIT) { route_neighborsol(packet); return; } @@ -418,12 +566,16 @@ void route_outgoing(vpn_packet_t *packet) break; case 0x0806: + if(packet->len < 42) { + ifdebug(TRAFFIC) logger(LOG_WARNING, _("Read too short packet")); + return; + } + route_arp(packet); return; default: - if(debug_lvl >= DEBUG_TRAFFIC) - syslog(LOG_WARNING, _("Cannot route packet: unknown type %hx"), type); + ifdebug(TRAFFIC) logger(LOG_WARNING, _("Cannot route packet: unknown type %hx"), type); return; } if(n) @@ -446,6 +598,12 @@ void route_outgoing(vpn_packet_t *packet) void route_incoming(node_t *source, vpn_packet_t *packet) { + if(packet->len < 14) { + ifdebug(TRAFFIC) logger(LOG_WARNING, _("Got too short packet from %s (%s)"), + source->name, source->hostname); + return; + } + switch (routing_mode) { case RMODE_ROUTER: { @@ -455,10 +613,20 @@ void route_incoming(node_t *source, vpn_packet_t *packet) type = ntohs(*((uint16_t *)(&packet->data[12]))); switch (type) { case 0x0800: + if(packet->len < 34) { + ifdebug(TRAFFIC) logger(LOG_WARNING, _("Read too short packet")); + return; + } + n = route_ipv4(packet); break; case 0x86DD: + if(packet->len < 54) { + ifdebug(TRAFFIC) logger(LOG_WARNING, _("Read too short packet")); + return; + } + n = route_ipv6(packet); break; @@ -469,7 +637,8 @@ void route_incoming(node_t *source, vpn_packet_t *packet) if(n) { if(n == myself) { - memcpy(packet->data, mymac.net.mac.address.x, 6); + if(overwrite_mac) + memcpy(packet->data, mymac.x, 6); write_packet(packet); } else send_packet(n, packet);