X-Git-Url: http://git.meshlink.io/?a=blobdiff_plain;f=src%2Froute.c;h=ee36a9bfe4b17c8289d85053312a7d44ed2692c3;hb=963c5055505f2fc117cd5efa06eaa02c9b2bf85d;hp=00b5298b3dacedd3c8a91d425318042418f1d7ff;hpb=e0dee537705cdbd005f6ab1fbef5ac71dc8411c0;p=meshlink diff --git a/src/route.c b/src/route.c index 00b5298b..ee36a9bf 100644 --- a/src/route.c +++ b/src/route.c @@ -1,7 +1,6 @@ /* route.c -- routing - Copyright (C) 2000-2002 Ivo Timmermans , - 2000-2002 Guus Sliepen + Copyright (C) 2014 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 @@ -13,485 +12,81 @@ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. - You should have received a copy of the GNU General Public License - along with this program; if not, write to the Free Software - Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. - - $Id: route.c,v 1.1.2.35 2002/03/15 15:40:40 guus Exp $ + You should have received a copy of the GNU General Public License along + with this program; if not, write to the Free Software Foundation, Inc., + 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ -#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 "system.h" +#include "logger.h" +#include "meshlink_internal.h" #include "net.h" -#include "connection.h" -#include "subnet.h" #include "route.h" -#include "protocol.h" -#include "device.h" - -#include "system.h" - -#ifndef s6_addr16 -#define s6_addr16 __u6_addr.__u6_addr16 -#endif - -int routing_mode = RMODE_ROUTER; -int priorityinheritance = 0; -int macexpire = 600; -subnet_t mymac; - -void learn_mac(mac_t *address) -{ - subnet_t *subnet; - avl_node_t *node; - connection_t *c; -cp - subnet = lookup_subnet_mac(address); +#include "utils.h" - /* 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"), - 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); +static bool checklength(node_t *source, vpn_packet_t *packet, uint16_t length) { + assert(length); - /* 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); - } - } - - 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) - { - 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); + if(packet->len < length) { + logger(source->mesh, MESHLINK_WARNING, "Got too short packet from %s", source->name); + return false; + } else { + return true; } - } -cp -} - -node_t *route_mac(vpn_packet_t *packet) -{ - subnet_t *subnet; -cp - /* 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; -} - -node_t *route_ipv6(vpn_packet_t *packet) -{ - 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 - 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; - - 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(ns->nd_ns_target.s6_addr16[0]), ntohs(ns->nd_ns_target.s6_addr16[1]), ntohs(ns->nd_ns_target.s6_addr16[2]), ntohs(ns->nd_ns_target.s6_addr16[3]), - ntohs(ns->nd_ns_target.s6_addr16[4]), ntohs(ns->nd_ns_target.s6_addr16[5]), ntohs(ns->nd_ns_target.s6_addr16[6]), ntohs(ns->nd_ns_target.s6_addr16[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 } -void route_arp(vpn_packet_t *packet) -{ - struct ether_arp *arp; - subnet_t *subnet; - unsigned char ipbuf[4]; -cp - /* First, snatch the source address from the ARP packet */ +void route(meshlink_handle_t *mesh, node_t *source, vpn_packet_t *packet) { + assert(source); - memcpy(mymac.net.mac.address.x, packet->data + 6, 6); + // TODO: route on name or key - /* 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) - */ + meshlink_packethdr_t *hdr = (meshlink_packethdr_t *) packet->data; + node_t *dest = lookup_node(mesh, (char *)hdr->destination); + logger(mesh, MESHLINK_DEBUG, "Routing packet from \"%s\" to \"%s\"\n", hdr->source, hdr->destination); - 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 Length + if(!checklength(source, packet, sizeof(*hdr))) { + return; + } - /* Check if it is for our own subnet */ - - if(subnet->owner == myself) - return; /* silently ignore */ + if(dest == NULL) { + //Lookup failed + logger(mesh, MESHLINK_WARNING, "Can't lookup the destination of a packet in the route() function. This should never happen!\n"); + logger(mesh, MESHLINK_WARNING, "Destination was: %s\n", hdr->destination); + return; + } - 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 */ + if(dest == mesh->self) { + const void *payload = packet->data + sizeof(*hdr); + size_t len = packet->len - sizeof(*hdr); - 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); /* ... */ + char hex[len * 2 + 1]; - 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 -} + if(mesh->log_level <= MESHLINK_DEBUG) { + bin2hex(payload, hex, len); // don't do this unless it's going to be logged + } -void route_outgoing(vpn_packet_t *packet) -{ - unsigned short int type; - node_t *n = NULL; -cp - /* FIXME: multicast? */ + logger(mesh, MESHLINK_DEBUG, "I received a packet for me with payload: %s\n", hex); - 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; + if(mesh->receive_cb) { + mesh->receive_cb(mesh, (meshlink_node_t *)source, payload, len); } - 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; - } + return; + } - 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; + if(!dest->status.reachable) { + //TODO: check what to do here, not just print a warning + logger(mesh, MESHLINK_WARNING, "The destination of a packet in the route() function is unreachable. Dropping packet.\n"); + return; + } - subnet = lookup_subnet_mac((mac_t *)(&packet->data[0])); + if(dest == source) { + logger(mesh, MESHLINK_ERROR, "Routing loop for packet from %s!", source->name); + return; + } - 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; - } + send_packet(mesh, dest, packet); + return; }