+static void check_reachability(void) {
+ splay_node_t *node, *next;
+ node_t *n;
+ char *name;
+ char *address, *port;
+ char *envp[7];
+ int i;
+
+ /* Check reachability status. */
+
+ for(node = node_tree->head; node; node = next) {
+ next = node->next;
+ n = node->data;
+
+ if(n->status.visited != n->status.reachable) {
+ n->status.reachable = !n->status.reachable;
+ n->last_state_change = time(NULL);
+
+ if(n->status.reachable) {
+ logger(DEBUG_TRAFFIC, LOG_DEBUG, "Node %s (%s) became reachable",
+ n->name, n->hostname);
+ } else {
+ logger(DEBUG_TRAFFIC, LOG_DEBUG, "Node %s (%s) became unreachable",
+ n->name, n->hostname);
+ }
+
+ if(experimental && OPTION_VERSION(n->options) >= 2)
+ n->status.sptps = true;
+
+ /* TODO: only clear status.validkey if node is unreachable? */
+
+ n->status.validkey = false;
+ n->last_req_key = 0;
+
+ n->maxmtu = MTU;
+ n->minmtu = 0;
+ n->mtuprobes = 0;
+
+ if(timeout_initialized(&n->mtuevent))
+ event_del(&n->mtuevent);
+
+ xasprintf(&envp[0], "NETNAME=%s", netname ? : "");
+ xasprintf(&envp[1], "DEVICE=%s", device ? : "");
+ xasprintf(&envp[2], "INTERFACE=%s", iface ? : "");
+ xasprintf(&envp[3], "NODE=%s", n->name);
+ sockaddr2str(&n->address, &address, &port);
+ xasprintf(&envp[4], "REMOTEADDRESS=%s", address);
+ xasprintf(&envp[5], "REMOTEPORT=%s", port);
+ envp[6] = NULL;
+
+ execute_script(n->status.reachable ? "host-up" : "host-down", envp);
+
+ xasprintf(&name,
+ n->status.reachable ? "hosts/%s-up" : "hosts/%s-down",
+ n->name);
+ execute_script(name, envp);
+
+ free(name);
+ free(address);
+ free(port);
+
+ for(i = 0; i < 6; i++)
+ free(envp[i]);
+
+ subnet_update(n, NULL, n->status.reachable);
+
+ if(!n->status.reachable) {
+ update_node_udp(n, NULL);
+ } else if(n->connection) {
+ if(n->status.sptps) {
+ if(n->connection->outgoing)
+ send_req_key(n);
+ } else {
+ send_ans_key(n);
+ }
+ }
+ }
+ }
+}