+ subnet_t *subnet;
+ cp();
+ subnet = lookup_subnet_ipv6((ipv6_t *)&packet->data[38]);
+ cp();
+ if(!subnet)
+ {
+ if(debug_lvl >= DEBUG_TRAFFIC)
+ {
+ syslog(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]));
+ }
+
+ return NULL;
+ }
+ cp();
+ return subnet->owner;
+}
+
+uint16_t inet_checksum(uint16_t *data, int len, uint16_t prevsum)
+{
+ uint32_t checksum = prevsum ^ 0xFFFF;
+
+ while(len--)
+ checksum += ntohs(*data++);
+
+ while(checksum >> 16)
+ checksum = (checksum & 0xFFFF) + (checksum >> 16);
+
+ return checksum ^ 0xFFFF;
+}
+
+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;
+ uint8_t junk[4];
+ } 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 */
+
+ memcpy(mymac.net.mac.address.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)
+ {
+ if(debug_lvl > DEBUG_TRAFFIC)
+ {
+ syslog(LOG_WARNING, _("Cannot route packet: received unknown type neighbor solicitation request"));
+ }
+ return;
+ }
+
+ /* 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.junk[0] = pseudo.junk[1] = pseudo.junk[2] = 0;
+ pseudo.junk[3] = IPPROTO_ICMPV6;
+
+ /* Generate checksum */
+
+ checksum = inet_checksum((uint16_t *)&pseudo, sizeof(pseudo)/2, ~0);
+ checksum = inet_checksum((uint16_t *)ns, sizeof(*ns)/2 + 4, checksum);
+
+ if(checksum)
+ {
+ if(debug_lvl >= DEBUG_TRAFFIC)
+ syslog(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)