X-Git-Url: https://tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=rt%2Froute.c;fp=rt%2Froute.c;h=4721763888a1b047c52225dbc754f9fb549856aa;hp=0000000000000000000000000000000000000000;hb=942ee816b88f9c35b456abab1864e5e2b811e5c8;hpb=92a3e63dc3841c4daa05fc2a25635fe9afacf08f diff --git a/rt/route.c b/rt/route.c new file mode 100644 index 00000000..47217638 --- /dev/null +++ b/rt/route.c @@ -0,0 +1,754 @@ +/* + route.c -- routing + Copyright (C) 2000-2004 Ivo Timmermans , + 2000-2004 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 + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + 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. + + $Id$ +*/ + +#include "system.h" + +#ifdef HAVE_NET_ETHERNET_H +#include +#endif +#ifdef HAVE_NET_IF_ARP_H +#include +#endif +#ifdef HAVE_NETINET_IP_ICMP_H +#include +#endif +#ifdef HAVE_NETINET_ICMP6_H +#include +#endif +#ifdef HAVE_NETINET_IF_ETHER_H +#include +#endif + +#include "logger/logger.h" +#include "rt/rt.h" +#include "rt/subnet.h" +#include "support/avl.h" +#include "support/ethernet.h" +#include "support/ipv4.h" +#include "support/ipv6.h" + +static mac_t mymac = {{0xFE, 0xFD, 0, 0, 0, 0}}; + +/* Sizes of various headers */ + +static const size_t ether_size = sizeof(struct ether_header); +static const size_t arp_size = sizeof(struct ether_arp); +static const size_t ip_size = sizeof(struct ip); +static const size_t icmp_size = sizeof(struct icmp) - sizeof(struct ip); +static const size_t ip6_size = sizeof(struct ip6_hdr); +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); + +static struct timeval expires(int seconds) { + struct timeval tv; + + gettimeofday(&tv, NULL); + tv.tv_sec += seconds; + + return tv; +} + +/* RFC 1071 */ + +static __inline__ uint16_t inet_checksum(const void *data, int len, uint16_t prevsum) { + const uint16_t *p = data; + uint32_t checksum = prevsum ^ 0xFFFF; + + while(len >= 2) { + checksum += *p++; + len -= 2; + } + + if(len) + checksum += *(uint8_t *)p; + + while(checksum >> 16) + checksum = (checksum & 0xFFFF) + (checksum >> 16); + + return ~checksum; +} + +static __inline__ bool ratelimit(int frequency) { + static time_t lasttime = 0; + static int count = 0; + time_t now = time(NULL); + + if(lasttime == now) { + if(++count > frequency) + return true; + } else { + lasttime = now; + count = 0; + } + + return false; +} + +static __inline__ bool checklength(node_t *source, int len, int minlen) { + if(len < minlen) { + logger(LOG_WARNING, _("Got too short packet from %s"), source->name); + return false; + } else + return true; +} + +static __inline__ void learn_mac(mac_t *address) { + subnet_t *subnet; + avl_node_t *node; + + subnet = subnet_get_mac(address); + + /* If we don't know this MAC address yet, store it */ + + if(!subnet) { + 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 = subnet_new(); + subnet->type = SUBNET_TYPE_MAC; + subnet->expires = expires(rt_macexpire); + subnet->net.mac.address = *address; + subnet->owner = myself; + subnet_add(subnet); + + /* And tell all other tinc daemons it's our MAC */ + +#if 0 + for(node = connection_tree->head; node; node = node->next) { + c = node->data; + if(c->status.active) + send_add_subnet(c, subnet); + } +#endif + } + + if(timerisset(&subnet->expires)) + subnet->expires = expires(rt_macexpire); +} + +void age_subnets(void) { + subnet_t *s; + +#if 0 + for(node = myself->subnet_tree->head; node; node = next) { + next = node->next; + s = node->data; + if(s->expires && s->expires < now) { + { + char netstr[MAXNETSTR]; + if(net2str(netstr, sizeof netstr, s)) + logger(LOG_INFO, _("Subnet %s expired"), netstr); + } + + for(node2 = connection_tree->head; node2; node2 = node2->next) { + c = node2->data; + if(c->status.active) + send_del_subnet(c, s); + } + + subnet_del(myself, s); + } + } +#endif +} + +static void send_packet(node_t *dest, const uint8_t *packet, int len) { + if(dest == myself) { + rt_vnd->send(rt_vnd, packet, len); + } else if (dest->tnl) { + dest->tnl->send_packet(dest->tnl, packet, len); + } else { + logger(LOG_ERR, _("No tunnel for packet destination %s!"), dest->name); + } +} + +static void broadcast_packet(node_t *source, const uint8_t *packet, int len) { + tnl_t *tnl; + edge_t *edge; + + if(source != myself) + send_packet(myself, packet, len); + + avl_foreach(rt_tnls, tnl, { + edge = tnl->data; + if(edge && edge->status.mst && edge->to != source) + send_packet(edge->to, packet, len); + }); +} + +static __inline__ void route_mac(node_t *source, const uint8_t *packet, int len) { + subnet_t *subnet; + + /* Learn source address */ + + if(source == myself) + learn_mac((mac_t *)(packet + 6)); + + /* Lookup destination address */ + + subnet = subnet_get_mac((mac_t *)(packet)); + + if(!subnet) { + broadcast_packet(source, packet, len); + return; + } + + if(subnet->owner == source) { + logger(LOG_WARNING, _("Packet looping back to %s!"), source->name); + return; + } + + send_packet(subnet->owner, packet, len); +} + +/* RFC 792 */ + +static void route_ipv4_unreachable(node_t *source, const uint8_t *packet, int len, uint8_t type, uint8_t code) { + uint8_t reply[ether_size + IP_MSS]; + + struct ip ip = {0}; + struct icmp icmp = {0}; + + struct in_addr ip_src; + struct in_addr ip_dst; + uint32_t oldlen; + + if(ratelimit(3)) + return; + + /* Copy headers from packet into properly aligned structs on the stack */ + + memcpy(&ip, packet + ether_size, ip_size); + + /* Remember original source and destination */ + + ip_src = ip.ip_src; + ip_dst = ip.ip_dst; + + oldlen = len - ether_size; + + if(type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) + icmp.icmp_nextmtu = htons(len - ether_size); + + if(oldlen >= IP_MSS - ip_size - icmp_size) + oldlen = IP_MSS - ip_size - icmp_size; + + /* Copy first part of original contents to ICMP message */ + + memmove(reply + ether_size + ip_size + icmp_size, packet + ether_size, oldlen); + + /* Fill in IPv4 header */ + + ip.ip_v = 4; + ip.ip_hl = ip_size / 4; + ip.ip_tos = 0; + ip.ip_len = htons(ip_size + icmp_size + oldlen); + ip.ip_id = 0; + ip.ip_off = 0; + ip.ip_ttl = 255; + ip.ip_p = IPPROTO_ICMP; + ip.ip_sum = 0; + ip.ip_src = ip_dst; + ip.ip_dst = ip_src; + + ip.ip_sum = inet_checksum(&ip, ip_size, ~0); + + /* Fill in ICMP header */ + + icmp.icmp_type = type; + icmp.icmp_code = code; + icmp.icmp_cksum = 0; + + icmp.icmp_cksum = inet_checksum(&icmp, icmp_size, ~0); + icmp.icmp_cksum = inet_checksum(packet + ether_size + ip_size + icmp_size, oldlen, icmp.icmp_cksum); + + /* Copy structs on stack back to packet */ + + memcpy(reply + ether_size, &ip, ip_size); + memcpy(reply + ether_size + ip_size, &icmp, icmp_size); + + send_packet(source, reply, ether_size + ip_size + icmp_size + oldlen); +} + +/* RFC 791 */ + +static __inline__ void fragment_ipv4_packet(node_t *dest, const uint8_t *packet, int len) { + struct ip ip; + char fragment[dest->tnl->mtu]; + int fraglen, maxlen, todo; + const uint8_t *offset; + uint16_t ip_off, origf; + + memcpy(&ip, packet + ether_size, ip_size); + + if(ip.ip_hl != ip_size / 4) + return; + + todo = ntohs(ip.ip_len) - ip_size; + + if(ether_size + ip_size + todo != len) { + logger(LOG_WARNING, _("Length of packet (%d) doesn't match length in IPv4 header (%d)"), len, ether_size + ip_size + todo); + return; + } + + logger(LOG_INFO, _("Fragmenting packet of %d bytes to %s"), len, dest->name); + + offset = packet + ether_size + ip_size; + maxlen = (dest->tnl->mtu - ether_size - ip_size) & ~0x7; + ip_off = ntohs(ip.ip_off); + origf = ip_off & ~IP_OFFMASK; + ip_off &= IP_OFFMASK; + + while(todo) { + fraglen = todo > maxlen ? maxlen : todo; + memcpy(fragment + ether_size + ip_size, offset, fraglen); + todo -= fraglen; + offset += fraglen; + + ip.ip_len = htons(ip_size + fraglen); + ip.ip_off = htons(ip_off | origf | (todo ? IP_MF : 0)); + ip.ip_sum = 0; + ip.ip_sum = inet_checksum(&ip, ip_size, ~0); + memcpy(fragment, packet, ether_size); + memcpy(fragment + ether_size, &ip, ip_size); + + send_packet(dest, fragment, ether_size + ip_size + fraglen); + + ip_off += fraglen / 8; + } +} + +static __inline__ void route_ipv4_unicast(node_t *source, const uint8_t *packet, int len) { + subnet_t *subnet; + node_t *via; + + subnet = subnet_get_ipv4((ipv4_t *)(packet + 30)); + + if(!subnet) { + logger(LOG_WARNING, _("Cannot route packet from %s: unknown IPv4 destination address %d.%d.%d.%d"), + source->name, + packet[30], + packet[31], + packet[32], + packet[33]); + + route_ipv4_unreachable(source, packet, len, ICMP_DEST_UNREACH, ICMP_NET_UNKNOWN); + return; + } + + if(subnet->owner == source) { + logger(LOG_WARNING, _("Packet looping back to %s!"), source->name); + return; + } + + if(!subnet->owner->status.reachable) + route_ipv4_unreachable(source, packet, len, ICMP_DEST_UNREACH, ICMP_NET_UNREACH); + + via = (subnet->owner->via == myself) ? subnet->owner->nexthop : subnet->owner->via; + + if(len > via->tnl->mtu && via != myself) { + logger(LOG_INFO, _("Packet for %s length %d larger than MTU %d"), subnet->owner->name, len, via->tnl->mtu); + if(packet[20] & 0x40) { + len = via->tnl->mtu; + route_ipv4_unreachable(source, packet, len, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED); + } else { + fragment_ipv4_packet(via, packet, len); + } + + return; + } + + send_packet(subnet->owner, packet, len); +} + +static __inline__ void route_ipv4(node_t *source, const uint8_t *packet, int len) { + if(!checklength(source, len, ether_size + ip_size)) + return; + + route_ipv4_unicast(source, packet, len); +} + +/* RFC 2463 */ + +static void route_ipv6_unreachable(node_t *source, const uint8_t *packet, int len, uint8_t type, uint8_t code) { + uint8_t reply[ether_size + IP_MSS]; + struct ip6_hdr ip6; + struct icmp6_hdr icmp6 = {0}; + 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(3)) + return; + + /* Copy headers from packet to structs on the stack */ + + memcpy(&ip6, packet + ether_size, ip6_size); + + /* Remember original source and destination */ + + pseudo.ip6_src = ip6.ip6_dst; + pseudo.ip6_dst = ip6.ip6_src; + + pseudo.length = len - ether_size; + + if(type == ICMP6_PACKET_TOO_BIG) + icmp6.icmp6_mtu = htonl(pseudo.length); + + if(pseudo.length >= IP_MSS - ip6_size - icmp6_size) + pseudo.length = IP_MSS - ip6_size - icmp6_size; + + /* Copy first part of original contents to ICMP message */ + + memcpy(reply + ether_size + ip6_size + icmp6_size, packet + ether_size, pseudo.length); + + /* Fill in IPv6 header */ + + ip6.ip6_flow = htonl(0x60000000UL); + ip6.ip6_plen = htons(icmp6_size + pseudo.length); + ip6.ip6_nxt = IPPROTO_ICMPV6; + ip6.ip6_hlim = 255; + ip6.ip6_src = pseudo.ip6_src; + ip6.ip6_dst = pseudo.ip6_dst; + + /* Fill in ICMP header */ + + icmp6.icmp6_type = type; + icmp6.icmp6_code = code; + icmp6.icmp6_cksum = 0; + + /* Create pseudo header */ + + pseudo.length = htonl(icmp6_size + pseudo.length); + pseudo.next = htonl(IPPROTO_ICMPV6); + + /* Generate checksum */ + + checksum = inet_checksum(&pseudo, sizeof(pseudo), ~0); + checksum = inet_checksum(&icmp6, icmp6_size, checksum); + checksum = inet_checksum(reply + ether_size + ip6_size + icmp6_size, ntohl(pseudo.length) - icmp6_size, checksum); + + icmp6.icmp6_cksum = checksum; + + /* Copy structs on stack back to packet */ + + memcpy(reply + ether_size, &ip6, ip6_size); + memcpy(reply + ether_size + ip6_size, &icmp6, icmp6_size); + + send_packet(source, reply, ether_size + ip6_size + ntohl(pseudo.length)); +} + +static __inline__ void route_ipv6_unicast(node_t *source, const uint8_t *packet, int len) { + subnet_t *subnet; + node_t *via; + + subnet = subnet_get_ipv6((ipv6_t *)(packet + 38)); + + if(!subnet) { + logger(LOG_WARNING, _("Cannot route packet from %s: unknown IPv6 destination address %hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx"), + source->name, + ntohs(*(uint16_t *)(packet + 38)), + ntohs(*(uint16_t *)(packet + 40)), + ntohs(*(uint16_t *)(packet + 42)), + ntohs(*(uint16_t *)(packet + 44)), + ntohs(*(uint16_t *)(packet + 46)), + ntohs(*(uint16_t *)(packet + 48)), + ntohs(*(uint16_t *)(packet + 50)), + ntohs(*(uint16_t *)(packet + 52))); + + route_ipv6_unreachable(source, packet, len, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_ADDR); + return; + } + + if(subnet->owner == source) { + logger(LOG_WARNING, _("Packet looping back to %s!"), source->name); + return; + } + + if(!subnet->owner->status.reachable) + route_ipv6_unreachable(source, packet, len, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOROUTE); + + via = (subnet->owner->via == myself) ? subnet->owner->nexthop : subnet->owner->via; + + if(len > via->tnl->mtu && via != myself) { + logger(LOG_INFO, _("Packet for %s length %d larger than MTU %d"), subnet->owner->name, len, via->tnl->mtu); + len = via->tnl->mtu; + route_ipv6_unreachable(source, packet, len, ICMP6_PACKET_TOO_BIG, 0); + return; + } + + send_packet(subnet->owner, packet, len); +} + +/* RFC 2461 */ + +static void route_neighborsol(node_t *source, const uint8_t *packet, int len) { + uint8_t reply[len]; + struct ip6_hdr ip6; + 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; + + if(!checklength(source, len, ether_size + ip6_size + ns_size + opt_size + ETH_ALEN)) + return; + + if(source != myself) { + logger(LOG_WARNING, _("Got neighbor solicitation request from %s while in router mode!"), source->name); + return; + } + + /* Copy headers from packet to structs on the stack */ + + memcpy(&ip6, packet + ether_size, ip6_size); + memcpy(&ns, packet + ether_size + ip6_size, ns_size); + memcpy(&opt, packet + ether_size + ip6_size + ns_size, opt_size); + + /* First, snatch the source address from the neighbor solicitation packet */ + + if(rt_overwrite_mac) + memcpy(mymac.x, packet + ETH_ALEN, ETH_ALEN); + + /* 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) { + logger(LOG_WARNING, _("Cannot route packet: received unknown type neighbor solicitation request")); + return; + } + + /* Create pseudo header */ + + pseudo.ip6_src = ip6.ip6_src; + pseudo.ip6_dst = ip6.ip6_dst; + pseudo.length = htonl(ns_size + opt_size + ETH_ALEN); + pseudo.next = htonl(IPPROTO_ICMPV6); + + /* Generate checksum */ + + checksum = inet_checksum(&pseudo, sizeof(pseudo), ~0); + checksum = inet_checksum(&ns, ns_size, checksum); + checksum = inet_checksum(&opt, opt_size, checksum); + checksum = inet_checksum(packet + ether_size + ip6_size + ns_size + opt_size, ETH_ALEN, checksum); + + if(checksum) { + logger(LOG_WARNING, _("Cannot route packet: checksum error for neighbor solicitation request")); + return; + } + + /* Check if the IPv6 address exists on the VPN */ + + subnet = subnet_get_ipv6((ipv6_t *) &ns.nd_ns_target); + + if(!subnet) { + 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; + } + + /* Check if it is for our own subnet */ + + if(subnet->owner == myself) + return; /* silently ignore */ + + /* Create neighbor advertation reply */ + + memcpy(reply, packet + ETH_ALEN, ETH_ALEN); /* copy destination address */ + memcpy(reply + ETH_ALEN, packet + ETH_ALEN, ETH_ALEN); /* copy destination address */ + reply[ETH_ALEN * 2 - 1] ^= 0xFF; /* mangle source address so it looks like it's not from us */ + + ip6.ip6_dst = ip6.ip6_src; /* swap destination and source protocoll address */ + ip6.ip6_src = ns.nd_ns_target; + + memcpy(reply + ether_size + ip6_size + ns_size + opt_size, reply + ETH_ALEN, ETH_ALEN); /* add fake source hard addr */ + + ns.nd_ns_cksum = 0; + ns.nd_ns_type = ND_NEIGHBOR_ADVERT; + ns.nd_ns_reserved = htonl(0x40000000UL); /* Set solicited flag */ + opt.nd_opt_type = ND_OPT_TARGET_LINKADDR; + + /* Create pseudo header */ + + pseudo.ip6_src = ip6.ip6_src; + pseudo.ip6_dst = ip6.ip6_dst; + pseudo.length = htonl(ns_size + opt_size + ETH_ALEN); + pseudo.next = htonl(IPPROTO_ICMPV6); + + /* Generate checksum */ + + checksum = inet_checksum(&pseudo, sizeof(pseudo), ~0); + checksum = inet_checksum(&ns, ns_size, checksum); + checksum = inet_checksum(&opt, opt_size, checksum); + checksum = inet_checksum(packet + ether_size + ip6_size + ns_size + opt_size, ETH_ALEN, checksum); + + ns.nd_ns_hdr.icmp6_cksum = checksum; + + /* Copy structs on stack back to packet */ + + memcpy(reply + ether_size, &ip6, ip6_size); + memcpy(reply + ether_size + ip6_size, &ns, ns_size); + memcpy(reply + ether_size + ip6_size + ns_size, &opt, opt_size); + + send_packet(source, reply, len); +} + +static __inline__ void route_ipv6(node_t *source, const uint8_t *packet, int len) { + if(!checklength(source, len, ether_size + ip6_size)) + return; + + if(packet[20] == IPPROTO_ICMPV6 && checklength(source, len, ether_size + ip6_size + icmp6_size) && packet[54] == ND_NEIGHBOR_SOLICIT) { + route_neighborsol(source, packet, len); + return; + } + + route_ipv6_unicast(source, packet, len); +} + +/* RFC 826 */ + +static void route_arp(node_t *source, const uint8_t *packet, int len) { + uint8_t reply[len]; + struct ether_arp arp; + subnet_t *subnet; + struct in_addr addr; + + if(!checklength(source, len, ether_size + arp_size)) + return; + + if(source != myself) { + logger(LOG_WARNING, _("Got ARP request from %s while in router mode!"), source->name); + return; + } + + /* First, snatch the source address from the ARP packet */ + + if(rt_overwrite_mac) + memcpy(mymac.x, packet + ETH_ALEN, ETH_ALEN); + + /* Copy headers from packet to structs on the stack */ + + memcpy(&arp, packet + ether_size, arp_size); + + /* Check if this is a valid ARP request */ + + 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) { + logger(LOG_WARNING, _("Cannot route packet: received unknown type ARP request")); + return; + } + + /* Check if the IPv4 address exists on the VPN */ + + subnet = subnet_get_ipv4((ipv4_t *) &arp.arp_tpa); + + if(!subnet) { + 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; + } + + /* Check if it is for our own subnet */ + + if(subnet->owner == myself) + return; /* silently ignore */ + + memcpy(reply, packet + ETH_ALEN, ETH_ALEN); /* copy destination address */ + memcpy(reply + ETH_ALEN, packet + ETH_ALEN, ETH_ALEN); /* copy destination address */ + reply[ETH_ALEN * 2 - 1] ^= 0xFF; /* mangle source address so it looks like it's not from us */ + + memcpy(&addr, arp.arp_tpa, sizeof(addr)); /* save protocol addr */ + memcpy(arp.arp_tpa, arp.arp_spa, sizeof(addr)); /* swap destination and source protocol address */ + memcpy(arp.arp_spa, &addr, sizeof(addr)); /* ... */ + + memcpy(arp.arp_tha, arp.arp_sha, ETH_ALEN); /* set target hard/proto addr */ + memcpy(arp.arp_sha, reply + ETH_ALEN, ETH_ALEN); /* add fake source hard addr */ + arp.arp_op = htons(ARPOP_REPLY); + + /* Copy structs on stack back to packet */ + + memcpy(reply + ether_size, &arp, arp_size); + + send_packet(source, reply, len); +} + +void route(node_t *source, const uint8_t *packet, int len) { + if(!checklength(source, len, ether_size)) + return; + + switch (rt_mode) { + case RT_MODE_ROUTER: + { + uint16_t type; + + type = ntohs(*((uint16_t *)(packet + 12))); + switch (type) { + case ETH_P_ARP: + route_arp(source, packet, len); + break; + + case ETH_P_IP: + route_ipv4(source, packet, len); + break; + + case ETH_P_IPV6: + route_ipv6(source, packet, len); + break; + + default: + logger(LOG_WARNING, _("Cannot route packet from %s: unknown type %hx"), source->name, type); + break; + } + } + break; + + case RT_MODE_SWITCH: + route_mac(source, packet, len); + break; + + case RT_MODE_HUB: + broadcast_packet(source, packet, len); + break; + } +}