- 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:
- if(debug_lvl >= DEBUG_TRAFFIC)
- syslog(LOG_WARNING, _("Cannot route packet: unknown type %hx"), type);
- return;
+ /* Lookup destination address */
+
+ memcpy(&dest, &packet->data[0], sizeof dest);
+ subnet = lookup_subnet_mac(NULL, &dest);
+
+ if(!subnet) {
+ broadcast_packet(source, packet);
+ return;
+ }
+
+ if(subnet->owner == source) {
+ ifdebug(TRAFFIC) logger(LOG_WARNING, "Packet looping back to %s (%s)!", source->name, source->hostname);
+ return;
+ }
+
+ if(forwarding_mode == FMODE_OFF && source != myself && subnet->owner != myself)
+ return;
+
+ // Handle packets larger than PMTU
+
+ node_t *via = (subnet->owner->via == myself) ? subnet->owner->nexthop : subnet->owner->via;
+
+ if(directonly && subnet->owner != via)
+ return;
+
+ if(via && packet->len > via->mtu && via != myself) {
+ ifdebug(TRAFFIC) logger(LOG_INFO, "Packet for %s (%s) length %d larger than MTU %d", subnet->owner->name, subnet->owner->hostname, packet->len, via->mtu);
+ uint16_t type = packet->data[12] << 8 | packet->data[13];
+ if(type == ETH_P_IP && packet->len > 590) {
+ if(packet->data[20] & 0x40) {
+ packet->len = via->mtu;
+ route_ipv4_unreachable(source, packet, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED);
+ } else {
+ fragment_ipv4_packet(via, packet);