+ 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;
+
+ cp();
+
+ if(!checklength(source, packet, ether_size + ip6_size + ns_size + opt_size + ETH_ALEN))
+ return;
+
+ if(source != myself) {
+ ifdebug(TRAFFIC) logger(LOG_WARNING, _("Got neighbor solicitation request from %s (%s) while in router mode!"), source->name, source->hostname);
+ return;
+ }
+
+ /* Copy headers from packet to structs on the stack */
+
+ memcpy(&ip6, packet->data + ether_size, ip6_size);
+ memcpy(&ns, packet->data + ether_size + ip6_size, ns_size);
+ memcpy(&opt, packet->data + ether_size + ip6_size + ns_size, opt_size);
+
+ /* First, snatch the source address from the neighbor solicitation packet */
+
+ if(overwrite_mac)
+ memcpy(mymac.x, packet->data + 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) {
+ ifdebug(TRAFFIC) 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->data + ether_size + ip6_size + ns_size + opt_size, ETH_ALEN, 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 */
+
+ subnet = lookup_subnet_ipv6((ipv6_t *) &ns.nd_ns_target);
+
+ 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]));
+
+ 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 + ETH_ALEN, ETH_ALEN); /* copy destination address */
+ packet->data[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(packet->data + ether_size + ip6_size + ns_size + opt_size, packet->data + 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->data + 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(packet->data + ether_size, &ip6, ip6_size);
+ memcpy(packet->data + ether_size + ip6_size, &ns, ns_size);
+ memcpy(packet->data + ether_size + ip6_size + ns_size, &opt, opt_size);
+
+ send_packet(source, packet);
+}
+
+/* RFC 2710 */
+
+#ifdef ENABLE_MULTICAST
+static void route_membershipreport(node_t *source, vpn_packet_t *packet)
+{
+ struct ip6_hdr ip6;
+ struct icmp6_hdr icmp6;
+ subnet_t *subnet, search = {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;
+
+ cp();
+
+ if(!checklength(source, packet, ether_size + ip6_size + icmp6_size + sizeof(ipv6_t)))
+ return;
+
+ if(source != myself) {
+ ifdebug(TRAFFIC) logger(LOG_WARNING, _("Got membership report from %s (%s) while in router mode!"), source->name, source->hostname);
+ return;
+ }
+
+ /* Copy headers from packet to structs on the stack */
+
+ memcpy(&ip6, packet->data + ether_size, ip6_size);
+ memcpy(&icmp6, packet->data + ether_size + ip6_size + 8, icmp6_size);
+
+ /* Create pseudo header */
+
+ pseudo.ip6_src = ip6.ip6_src;
+ pseudo.ip6_dst = ip6.ip6_dst;
+ pseudo.length = htonl(icmp6_size + sizeof(ipv6_t));
+ pseudo.next = htonl(IPPROTO_ICMPV6);
+
+ /* Generate checksum */
+
+ checksum = inet_checksum(&pseudo, sizeof(pseudo), ~0);
+ checksum = inet_checksum(&icmp6, icmp6_size, checksum);
+ checksum = inet_checksum(packet->data + ether_size + ip6_size + 8 + icmp6_size, sizeof(ipv6_t), checksum);
+
+ if(checksum) {
+ ifdebug(TRAFFIC) logger(LOG_WARNING, _("Cannot route packet: checksum error for membership report"));
+ return;
+ }
+
+ /* Check if the IPv6 address exists on the VPN */
+
+ search.type = SUBNET_IPV6;
+ search.net.ipv6.address = *(ipv6_t *)(packet->data + ether_size + ip6_size + 8 + icmp6_size);
+ search.net.ipv6.prefixlength = 128;
+ search.owner = myself;
+
+ subnet = avl_search(myself->subnet_tree, &search);
+
+ if(!subnet) {
+ avl_node_t *node;
+ connection_t *c;
+
+ ifdebug(TRAFFIC) logger(LOG_WARNING, _("Learned new IPv6 multicast address %hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx"),
+ ntohs(*(uint16_t *) &packet->data[70]),
+ ntohs(*(uint16_t *) &packet->data[72]),
+ ntohs(*(uint16_t *) &packet->data[74]),
+ ntohs(*(uint16_t *) &packet->data[76]),
+ ntohs(*(uint16_t *) &packet->data[78]),
+ ntohs(*(uint16_t *) &packet->data[80]),
+ ntohs(*(uint16_t *) &packet->data[82]),
+ ntohs(*(uint16_t *) &packet->data[84]));
+
+ subnet = new_subnet();
+ subnet->type = SUBNET_IPV6;
+ subnet->net.ipv6.address = *(ipv6_t *)(packet->data + ether_size + ip6_size + 8 + icmp6_size);
+ subnet->net.ipv6.prefixlength = 128;
+ subnet->expires = now + multicastexpire;
+ subnet_add(myself, subnet);
+
+ /* And tell all other tinc daemons it's ours */
+
+ for(node = connection_tree->head; node; node = node->next) {
+ c = node->data;
+ if(c->status.active)
+ send_add_subnet(c, subnet);