- /* 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"));
- 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]);
- 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;
- }