-void route_neighborsol(vpn_packet_t *packet)
-{
- struct ip6_hdr *hdr;
- struct nd_neighbor_solicit *ns;
- struct nd_opt_hdr *opt;
- subnet_t *subnet;
- short int cksum;
-
- 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(struct ip6_hdr));
- opt = (struct nd_opt_hdr *)(packet->data + 14 + sizeof(struct ip6_hdr) + sizeof(struct nd_neighbor_solicit));
-
- /* 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;
- }
-
- /* Check if the IPv6 address exists on the VPN */
-#if 0
- subnet = lookup_subnet_ipv6((ipv6_t *)&ns->nd_ns_target);
-
- if(!subnet)
- {
- if(debug_lvl >= DEBUG_TRAFFIC)
- {
- syslog(LOG_WARNING, _("Cannot route packet: neighbor solicitation request for unknown address %hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx"),
- ntohs(ns->nd_ns_target.s6_addr16[0]), ntohs(ns->nd_ns_target.s6_addr16[1]), ntohs(ns->nd_ns_target.s6_addr16[2]), ntohs(ns->nd_ns_target.s6_addr16[3]),
- ntohs(ns->nd_ns_target.s6_addr16[4]), ntohs(ns->nd_ns_target.s6_addr16[5]), ntohs(ns->nd_ns_target.s6_addr16[6]), ntohs(ns->nd_ns_target.s6_addr16[7]));
- }
-
- return;
- }
-
- /* Check if it is for our own subnet */
-
- if(subnet->owner == myself)
- return; /* silently ignore */
-#endif
-
- syslog(LOG_DEBUG, "Neighbor solicitation request with checksum %hx", ntohs(ns->nd_ns_hdr.icmp6_cksum));
-
- /* Create pseudo header */
+void age_subnets(void) {
+ subnet_t *s;
+ connection_t *c;
+ avl_node_t *node, *next, *node2;
+
+ for(node = myself->subnet_tree->head; node; node = next) {
+ next = node->next;
+ s = node->data;
+ if(s->expires && s->expires <= now) {
+ ifdebug(TRAFFIC) {
+ 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_update(myself, s, false);
+ subnet_del(myself, s);
+ }
+ }
+}
+
+/* RFC 792 */
+
+static void route_ipv4_unreachable(node_t *source, vpn_packet_t *packet, length_t ether_size, uint8_t type, uint8_t code) {
+ 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;
+
+ /* Swap Ethernet source and destination addresses */
+
+ swap_mac_addresses(packet);
+
+ /* Copy headers from packet into properly aligned structs on the stack */
+
+ memcpy(&ip, packet->data + ether_size, ip_size);
+
+ /* Remember original source and destination */
+
+ ip_src = ip.ip_src;
+ ip_dst = ip.ip_dst;
+
+ oldlen = packet->len - ether_size;
+
+ if(type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED)
+ icmp.icmp_nextmtu = htons(packet->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(packet->data + ether_size + ip_size + icmp_size, packet->data + 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->data + ether_size + ip_size + icmp_size, oldlen, icmp.icmp_cksum);
+
+ /* Copy structs on stack back to packet */
+
+ memcpy(packet->data + ether_size, &ip, ip_size);
+ memcpy(packet->data + ether_size + ip_size, &icmp, icmp_size);
+
+ packet->len = ether_size + ip_size + icmp_size + oldlen;
+
+ send_packet(source, packet);
+}
+
+/* RFC 791 */
+
+static void fragment_ipv4_packet(node_t *dest, vpn_packet_t *packet, length_t ether_size) {
+ struct ip ip;
+ vpn_packet_t fragment;
+ int len, maxlen, todo;
+ uint8_t *offset;
+ uint16_t ip_off, origf;
+
+ memcpy(&ip, packet->data + ether_size, ip_size);
+ fragment.priority = packet->priority;
+
+ if(ip.ip_hl != ip_size / 4)
+ return;
+
+ todo = ntohs(ip.ip_len) - ip_size;
+
+ if(ether_size + ip_size + todo != packet->len) {
+ ifdebug(TRAFFIC) logger(LOG_WARNING, "Length of packet (%d) doesn't match length in IPv4 header (%d)", packet->len, (int)(ether_size + ip_size + todo));
+ return;
+ }
+
+ ifdebug(TRAFFIC) logger(LOG_INFO, "Fragmenting packet of %d bytes to %s (%s)", packet->len, dest->name, dest->hostname);
+
+ offset = packet->data + ether_size + ip_size;
+ maxlen = (dest->mtu - ether_size - ip_size) & ~0x7;
+ ip_off = ntohs(ip.ip_off);
+ origf = ip_off & ~IP_OFFMASK;
+ ip_off &= IP_OFFMASK;
+
+ while(todo) {
+ len = todo > maxlen ? maxlen : todo;
+ memcpy(fragment.data + ether_size + ip_size, offset, len);
+ todo -= len;
+ offset += len;
+
+ ip.ip_len = htons(ip_size + len);
+ 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.data, packet->data, ether_size);
+ memcpy(fragment.data + ether_size, &ip, ip_size);
+ fragment.len = ether_size + ip_size + len;
+
+ send_packet(dest, &fragment);
+
+ ip_off += len / 8;
+ }
+}
+
+static void route_ipv4_unicast(node_t *source, vpn_packet_t *packet) {
+ subnet_t *subnet;
+ node_t *via;
+ ipv4_t dest;
+
+ memcpy(&dest, &packet->data[30], sizeof dest);
+ subnet = lookup_subnet_ipv4(&dest);
+
+ if(!subnet) {
+ ifdebug(TRAFFIC) logger(LOG_WARNING, "Cannot route packet from %s (%s): unknown IPv4 destination address %d.%d.%d.%d",
+ source->name, source->hostname,
+ dest.x[0],
+ dest.x[1],
+ dest.x[2],
+ dest.x[3]);
+
+ route_ipv4_unreachable(source, packet, ether_size, ICMP_DEST_UNREACH, ICMP_NET_UNKNOWN);
+ return;
+ }
+
+ if(subnet->owner == source) {
+ ifdebug(TRAFFIC) logger(LOG_WARNING, "Packet looping back to %s (%s)!", source->name, source->hostname);
+ return;
+ }
+
+ if(!subnet->owner->status.reachable)
+ return route_ipv4_unreachable(source, packet, ether_size, ICMP_DEST_UNREACH, ICMP_NET_UNREACH);