X-Git-Url: http://git.meshlink.io/?a=blobdiff_plain;f=src%2Froute.c;h=ee36a9bfe4b17c8289d85053312a7d44ed2692c3;hb=be83b0af60449c7b35d17d97f2e6dc12f611e831;hp=382a6dde68dc8817c0d3391d0f5749529d97cae5;hpb=5db596c6844169f1eb5f804b72abe99d067aaa5a;p=meshlink diff --git a/src/route.c b/src/route.c index 382a6dde..ee36a9bf 100644 --- a/src/route.c +++ b/src/route.c @@ -1,7 +1,6 @@ /* route.c -- routing - Copyright (C) 2000-2003 Ivo Timmermans , - 2000-2003 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 @@ -13,653 +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 1.1.2.57 2003/07/12 17:41:47 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" - -#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 -#endif -#include -#include -#ifdef HAVE_NETINET_IP6_H -#include -#include -#endif -#include -#include -#include -#include -#ifdef HAVE_INTTYPES_H -#include -#endif - -#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 "logger.h" - -#include "system.h" - -/* Missing definitions */ - -#ifndef ETHER_ADDR_LEN -#define ETHER_ADDR_LEN 6 -#endif +#include "utils.h" -#ifndef ICMP_DEST_UNREACH -#define ICMP_DEST_UNREACH 3 -#endif +static bool checklength(node_t *source, vpn_packet_t *packet, uint16_t length) { + assert(length); -#ifndef ICMP_NET_UNKNOWN -#define ICMP_NET_UNKNOWN 6 -#endif - -#ifndef ICMP_NET_UNREACH -#define ICMP_NET_UNREACH 0 -#endif - -int routing_mode = RMODE_ROUTER; -int priorityinheritance = 0; -int macexpire = 600; -int overwrite_mac = 0; -static mac_t mymac = {{0xFE, 0xFD, 0, 0, 0, 0}}; - -/* RFC 1071 */ - -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(packet->len < length) { + logger(source->mesh, MESHLINK_WARNING, "Got too short packet from %s", source->name); + return false; + } else { + return true; } - - if(len) - checksum += *(unsigned char *)p; - - while(checksum >> 16) - checksum = (checksum & 0xFFFF) + (checksum >> 16); - - return ~checksum; } -static int ratelimit(void) { - static time_t lasttime = 0; - - if(lasttime == now) - return 1; - - lasttime = now; - return 0; -} - -static void learn_mac(mac_t *address) -{ - subnet_t *subnet; - avl_node_t *node; - connection_t *c; +void route(meshlink_handle_t *mesh, node_t *source, vpn_packet_t *packet) { + assert(source); - cp(); - - subnet = lookup_subnet_mac(address); - - /* If we don't know this MAC address yet, store it */ - - if(!subnet || subnet->owner != myself) { - 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]); - - 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); - } - } - - 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) { - 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; - if(c->status.active) - send_del_subnet(c, s); - } - - subnet_del(myself, s); - } - } -} + // TODO: route on name or key -static node_t *route_mac(vpn_packet_t *packet) -{ - subnet_t *subnet; + 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); - 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; -} - -/* 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; - - cp(); - - if(priorityinheritance) - packet->priority = packet->data[15]; - - subnet = lookup_subnet_ipv4((ipv4_t *) & packet->data[30]); - - if(!subnet) { - 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; -} - -/* 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()) + //Check Length + if(!checklength(source, packet, sizeof(*hdr))) { 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]); - - if(!subnet) { - 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; -} - -/* RFC 2461 */ - -static void route_neighborsol(vpn_packet_t *packet) -{ - struct ip6_hdr *hdr; - struct nd_neighbor_solicit *ns; - struct nd_opt_hdr *opt; - subnet_t *subnet; - 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; - - 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 */ - - 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) { - ifdebug(TRAFFIC) logger(LOG_WARNING, _("Cannot route packet: received unknown type neighbor solicitation request")); + 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; } - /* Create pseudo header */ + if(dest == mesh->self) { + const void *payload = packet->data + sizeof(*hdr); + size_t len = packet->len - sizeof(*hdr); - 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.next = htonl(IPPROTO_ICMPV6); + char hex[len * 2 + 1]; - /* Generate checksum */ - - checksum = inet_checksum(&pseudo, sizeof(pseudo), ~0); - checksum = inet_checksum(ns, sizeof(*ns) + 8, checksum); - - if(checksum) { - ifdebug(TRAFFIC) logger(LOG_WARNING, _("Cannot route packet: checksum error for neighbor solicitation request")); - return; - } - - /* Check if the IPv6 address exists on the VPN */ + if(mesh->log_level <= MESHLINK_DEBUG) { + bin2hex(payload, hex, len); // don't do this unless it's going to be logged + } - subnet = lookup_subnet_ipv6((ipv6_t *) & ns->nd_ns_target); + logger(mesh, MESHLINK_DEBUG, "I received a packet for me with payload: %s\n", hex); - if(!subnet) { - 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])); + if(mesh->receive_cb) { + mesh->receive_cb(mesh, (meshlink_node_t *)source, payload, len); + } 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.next = htonl(IPPROTO_ICMPV6); - - /* Generate checksum */ - - checksum = inet_checksum(&pseudo, sizeof(pseudo), ~0); - checksum = inet_checksum(ns, sizeof(*ns) + 8, checksum); - - ns->nd_ns_hdr.icmp6_cksum = checksum; - - write_packet(packet); -} - -/* RFC 826 */ - -static void route_arp(vpn_packet_t *packet) -{ - struct ether_arp *arp; - subnet_t *subnet; - uint8_t ipbuf[4]; - - cp(); - - /* First, snatch the source address from the ARP packet */ - - 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). - 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 || - arp->arp_hln != ETHER_ADDR_LEN || arp->arp_pln != 4 || ntohs(arp->arp_op) != ARPOP_REQUEST) { - ifdebug(TRAFFIC) logger(LOG_WARNING, _("Cannot route packet: received unknown type ARP request")); + 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; } - /* Check if the IPv4 address exists on the VPN */ - - 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"), - arp->arp_tpa[0], arp->arp_tpa[1], arp->arp_tpa[2], - arp->arp_tpa[3]); + if(dest == source) { + logger(mesh, MESHLINK_ERROR, "Routing loop for packet from %s!", source->name); 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); -} - -void route_outgoing(vpn_packet_t *packet) -{ - uint16_t type; - node_t *n = NULL; - - cp(); - - /* FIXME: multicast? */ - - switch (routing_mode) { - case RMODE_ROUTER: - type = ntohs(*((uint16_t *)(&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: - ifdebug(TRAFFIC) logger(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; - uint16_t type; - - type = ntohs(*((uint16_t *)(&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) { - if(overwrite_mac) - memcpy(packet->data, mymac.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; - } + send_packet(mesh, dest, packet); + return; }