X-Git-Url: https://www.tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Froute.c;h=dcf43e41e712c5a845a3f6727fda456ca0ec60d9;hp=0509b962ca4a8279b710662cd68c237e814652b6;hb=5c2d74de86d1acb3774a20357ad815d000f8a7f6;hpb=698191fd2f512f3618e2d60592fcd57cd750b965 diff --git a/src/route.c b/src/route.c index 0509b962..dcf43e41 100644 --- a/src/route.c +++ b/src/route.c @@ -1,7 +1,7 @@ /* route.c -- routing - Copyright (C) 2000 Ivo Timmermans , - 2000 Guus Sliepen + Copyright (C) 2000-2002 Ivo Timmermans , + 2000-2002 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 @@ -17,96 +17,477 @@ along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. - $Id: route.c,v 1.1.2.2 2000/11/04 22:57:33 guus Exp $ + $Id: route.c,v 1.1.2.37 2002/03/19 00:08:23 guus Exp $ */ #include "config.h" +#if defined(HAVE_FREEBSD) || defined(HAVE_OPENBSD) + #include +#endif +#include +#include +#if defined(HAVE_SOLARIS) || defined(HAVE_OPENBSD) + #include + #define ETHER_ADDR_LEN 6 +#else + #include +#endif +#include +#include +#include #include #include +#include +#include + +#include #include "net.h" -#include "connlist.h" +#include "connection.h" +#include "subnet.h" +#include "route.h" +#include "protocol.h" +#include "device.h" #include "system.h" -int routing_mode = 0; /* Will be used to determine if we route by MAC or by payload's protocol */ +int routing_mode = RMODE_ROUTER; +int priorityinheritance = 0; +int macexpire = 600; +subnet_t mymac; -conn_list_t *route_packet(vpn_packet_t *packet) +void learn_mac(mac_t *address) { - unsigned short type; + subnet_t *subnet; + avl_node_t *node; + connection_t *c; cp - type = ntohs(*((unsigned short*)(&packet.data[12]))) + subnet = lookup_subnet_mac(address); - if(routing_mode) + /* If we don't know this MAC address yet, store it */ + + if(!subnet || subnet->owner!=myself) { - return route_mac(packet); + if(debug_lvl >= DEBUG_TRAFFIC) + syslog(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_add(myself, subnet); + + /* And tell all other tinc daemons it's our MAC */ + + for(node = connection_tree->head; node; node = node->next) + { + c = (connection_t *)node->data; + if(c->status.active) + send_add_subnet(c, subnet); + } } - switch(type) + subnet->net.mac.lastseen = now; +} + +void age_mac(void) +{ + subnet_t *s; + connection_t *c; + avl_node_t *node, *next, *node2; +cp + for(node = myself->subnet_tree->head; node; node = next) { - case 0x0800: - return route_ipv4(packet); - case 0x86DD: - return route_ipv6(packet); -/* - case 0x8137: - return route_ipx(packet); - case 0x0806: - return route_arp(packet); -*/ - default: - if(debug_lvl >= DEBUG_TRAFFIC) - { - syslog(LOG_WARNING, _("Cannot route packet: unknown type %hx"), type); - } - return NULL; - } + next = node->next; + s = (subnet_t *)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"), + 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; + if(c->status.active) + send_del_subnet(c, s); + } + subnet_del(myself, s); + } + } +cp } -conn_list_t *route_mac(vpn_packet_t *packet) +node_t *route_mac(vpn_packet_t *packet) { - conn_list_t *cl; + subnet_t *subnet; cp - cl = lookup_subnet_mac((mac_t *)(&packet.data[6])); - if(!cl) - if(debug_lvl >= DEBUG_TRAFFIC) - { - syslog(LOG_WARNING, _("Cannot route packet: unknown destination address %x:%x:%x:%x:%x:%x"), - packet.data[6], - packet.data[7], - packet.data[8], - packet.data[9], - packet.data[10], - packet.data[11]); - } -cp - return cl; + /* 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; } +node_t *route_ipv4(vpn_packet_t *packet) +{ + subnet_t *subnet; +cp + if(priorityinheritance) + packet->priority = packet->data[15]; + + subnet = lookup_subnet_ipv4((ipv4_t *)&packet->data[30]); +cp + if(!subnet) + { + if(debug_lvl >= DEBUG_TRAFFIC) + { + syslog(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]); + } + + return NULL; + } +cp + return subnet->owner; +} -conn_list_t *route_ipv4(vpn_packet_t *packet) +node_t *route_ipv6(vpn_packet_t *packet) { - ipv4_t dest; - conn_list_t *cl; + subnet_t *subnet; +cp + subnet = lookup_subnet_ipv6((ipv6_t *)&packet->data[38]); +cp + 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(*(short unsigned int *)&packet->data[38]), + ntohs(*(short unsigned int *)&packet->data[40]), + ntohs(*(short unsigned int *)&packet->data[42]), + ntohs(*(short unsigned int *)&packet->data[44]), + ntohs(*(short unsigned int *)&packet->data[46]), + ntohs(*(short unsigned int *)&packet->data[48]), + ntohs(*(short unsigned int *)&packet->data[50]), + ntohs(*(short unsigned int *)&packet->data[52])); + } + + return NULL; + } cp - dest = ntohl(*((unsigned long*)(&packet.data[30]); + return subnet->owner; +} + +unsigned short int inet_checksum(unsigned short int *data, int len, unsigned short int prevsum) +{ + unsigned long int checksum = prevsum ^ 0xFFFF; + + while(len--) + checksum += ntohs(*data++); + + while(checksum >> 16) + checksum = (checksum & 0xFFFF) + (checksum >> 16); + + return checksum ^ 0xFFFF; +} + +void route_neighborsol(vpn_packet_t *packet) +{ + struct ip6_hdr *hdr; + struct nd_neighbor_solicit *ns; + struct nd_opt_hdr *opt; + subnet_t *subnet; + short unsigned int checksum; - cl = lookup_subnet_ipv4(dest); - if(!cl) - if(debug_lvl >= DEBUG_TRAFFIC) - { - syslog(LOG_WARNING, _("Cannot route packet: unknown destination address %d.%d.%d.%d"), - packet.data[30], packet.data[31], packet.data[32], packet.data[33]); - } + struct { + struct in6_addr ip6_src; /* source address */ + struct in6_addr ip6_dst; /* destination address */ + uint32_t length; + uint8_t junk[4]; + } pseudo; + +cp + hdr = (struct ip6_hdr *)(packet->data + 14); + ns = (struct nd_neighbor_solicit *)(packet->data + 14 + sizeof(*hdr)); + opt = (struct nd_opt_hdr *)(packet->data + 14 + sizeof(*hdr) + sizeof(*ns)); + + /* First, snatch the source address from the neighbor solicitation packet */ + + memcpy(mymac.net.mac.address.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")); + } + return; + } + + /* Create pseudo header */ + + 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; + + /* Generate checksum */ + + checksum = inet_checksum((unsigned short int *)&pseudo, sizeof(pseudo)/2, ~0); + checksum = inet_checksum((unsigned short int *)ns, sizeof(*ns)/2 + 4, checksum); + + if(checksum) + { + if(debug_lvl >= DEBUG_TRAFFIC) + syslog(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); + + 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])); + } + + return; + } + + /* Check if it is for our own subnet */ + + if(subnet->owner == myself) + return; /* silently ignore */ + + /* Create neighbor advertation reply */ + + memcpy(packet->data, packet->data + ETHER_ADDR_LEN, ETHER_ADDR_LEN); /* copy destination address */ + packet->data[ETHER_ADDR_LEN*2 - 1] ^= 0xFF; /* mangle source address so it looks like it's not from us */ + + memcpy(&hdr->ip6_dst, &hdr->ip6_src, 16); /* swap destination and source protocol address */ + memcpy(&hdr->ip6_src, &ns->nd_ns_target, 16); /* ... */ + + memcpy((char *)opt + sizeof(*opt), packet->data + ETHER_ADDR_LEN, 6); /* add fake source hard addr */ + + ns->nd_ns_hdr.icmp6_cksum = 0; + ns->nd_ns_hdr.icmp6_type = ND_NEIGHBOR_ADVERT; + ns->nd_ns_hdr.icmp6_dataun.icmp6_un_data8[0] = 0x40; /* Set solicited flag */ + ns->nd_ns_hdr.icmp6_dataun.icmp6_un_data8[1] = ns->nd_ns_hdr.icmp6_dataun.icmp6_un_data8[2] = ns->nd_ns_hdr.icmp6_dataun.icmp6_un_data8[3] = 0; + opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; + + /* Create pseudo header */ + + 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; + + /* Generate checksum */ + + checksum = inet_checksum((unsigned short int *)&pseudo, sizeof(pseudo)/2, ~0); + checksum = inet_checksum((unsigned short int *)ns, sizeof(*ns)/2 + 4, checksum); + + ns->nd_ns_hdr.icmp6_cksum = htons(checksum); + + write_packet(packet); cp - return cl; } -conn_list_t *route_ipv6(vpn_packet_t *packet) +void route_arp(vpn_packet_t *packet) { + struct ether_arp *arp; + subnet_t *subnet; + unsigned char ipbuf[4]; cp - syslog(LOG_WARNING, _("Cannot route packet: IPv6 routing not implemented yet")); + /* First, snatch the source address from the ARP packet */ + + memcpy(mymac.net.mac.address.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). + Most of the code here is taken from choparp.c by Takamichi Tateoka (tree@mma.club.uec.ac.jp) + */ + + arp = (struct ether_arp *)(packet->data + 14); + + /* Check if this is a valid ARP request */ + + if(ntohs(arp->arp_hrd) != ARPHRD_ETHER || + ntohs(arp->arp_pro) != ETHERTYPE_IP || + (int) (arp->arp_hln) != ETHER_ADDR_LEN || + (int) (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")); + } + return; + } + + /* Check if the IPv4 address exists on the VPN */ + + 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"), + arp->arp_tpa[0], arp->arp_tpa[1], arp->arp_tpa[2], arp->arp_tpa[3]); + } + + return; + } + + /* Check if it is for our own subnet */ + + if(subnet->owner == myself) + return; /* silently ignore */ + + memcpy(packet->data, packet->data + ETHER_ADDR_LEN, ETHER_ADDR_LEN); /* copy destination address */ + packet->data[ETHER_ADDR_LEN*2 - 1] ^= 0xFF; /* mangle source address so it looks like it's not from us */ + + memcpy(ipbuf, arp->arp_tpa, 4); /* save protocol addr */ + memcpy(arp->arp_tpa, arp->arp_spa, 4); /* swap destination and source protocol address */ + memcpy(arp->arp_spa, ipbuf, 4); /* ... */ + + memcpy(arp->arp_tha, arp->arp_sha, 10); /* set target hard/proto addr */ + memcpy(arp->arp_sha, packet->data + ETHER_ADDR_LEN, ETHER_ADDR_LEN); /* add fake source hard addr */ + arp->arp_op = htons(ARPOP_REPLY); + + write_packet(packet); cp - return NULL; +} + +void route_outgoing(vpn_packet_t *packet) +{ + unsigned short int type; + node_t *n = NULL; +cp + /* FIXME: multicast? */ + + switch(routing_mode) + { + case RMODE_ROUTER: + type = ntohs(*((unsigned short*)(&packet->data[12]))); + switch(type) + { + case 0x0800: + n = route_ipv4(packet); + break; + case 0x86DD: + if(packet->data[20] == IPPROTO_ICMPV6 && packet->data[54] == ND_NEIGHBOR_SOLICIT) + { + route_neighborsol(packet); + return; + } + n = route_ipv6(packet); + break; + case 0x0806: + route_arp(packet); + return; + default: + if(debug_lvl >= DEBUG_TRAFFIC) + { + syslog(LOG_WARNING, _("Cannot route packet: unknown type %hx"), type); + } + return; + } + if(n) + send_packet(n, packet); + break; + + case RMODE_SWITCH: + n = route_mac(packet); + if(n) + send_packet(n, packet); + else + broadcast_packet(myself, packet); + break; + + case RMODE_HUB: + broadcast_packet(myself, packet); + break; + } +} + +void route_incoming(node_t *source, vpn_packet_t *packet) +{ + switch(routing_mode) + { + case RMODE_ROUTER: + { + node_t *n = NULL; + unsigned short int type; + + type = ntohs(*((unsigned short*)(&packet->data[12]))); + switch(type) + { + case 0x0800: + n = route_ipv4(packet); + break; + case 0x86DD: + n = route_ipv6(packet); + break; + default: + n = myself; + break; + } + + if(n) + { + if(n == myself) + { + memcpy(packet->data, mymac.net.mac.address.x, 6); + 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); + } + } + break; + case RMODE_HUB: + broadcast_packet(source, packet); /* Spread it on */ + write_packet(packet); + break; + } }