2 net.c -- most of the network code
3 Copyright (C) 1998-2005 Ivo Timmermans,
4 2000-2010 Guus Sliepen <guus@tinc-vpn.org>
5 2006 Scott Lamb <slamb@slamb.org>
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License along
18 with this program; if not, write to the Free Software Foundation, Inc.,
19 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
25 #include "splay_tree.h"
27 #include "connection.h"
39 int contradicting_add_edge = 0;
40 int contradicting_del_edge = 0;
42 /* Purge edges and subnets of unreachable nodes. Use carefully. */
45 splay_node_t *nnode, *nnext, *enode, *enext, *snode, *snext;
50 ifdebug(PROTOCOL) logger(LOG_DEBUG, "Purging unreachable nodes");
52 /* Remove all edges and subnets owned by unreachable nodes. */
54 for(nnode = node_tree->head; nnode; nnode = nnext) {
58 if(!n->status.reachable) {
59 ifdebug(SCARY_THINGS) logger(LOG_DEBUG, "Purging node %s (%s)", n->name,
62 for(snode = n->subnet_tree->head; snode; snode = snext) {
65 send_del_subnet(broadcast, s);
70 for(enode = n->edge_tree->head; enode; enode = enext) {
74 send_del_edge(broadcast, e);
80 /* Check if anyone else claims to have an edge to an unreachable node. If not, delete node. */
82 for(nnode = node_tree->head; nnode; nnode = nnext) {
86 if(!n->status.reachable) {
87 for(enode = edge_weight_tree->head; enode; enode = enext) {
95 if(!enode && (!strictsubnets || !n->subnet_tree->head))
96 /* in strictsubnets mode do not delete nodes with subnets */
103 Terminate a connection:
105 - Remove associated edge and tell other connections about it if report = true
106 - Check if we need to retry making an outgoing connection
107 - Deactivate the host
109 void terminate_connection(connection_t *c, bool report) {
110 ifdebug(CONNECTIONS) logger(LOG_NOTICE, "Closing connection with %s (%s)",
111 c->name, c->hostname);
113 c->status.active = false;
116 c->node->connection = NULL;
119 closesocket(c->socket);
122 if(report && !tunnelserver)
123 send_del_edge(broadcast, c->edge);
127 /* Run MST and SSSP algorithms */
131 /* If the node is not reachable anymore but we remember it had an edge to us, clean it up */
133 if(report && !c->node->status.reachable) {
135 e = lookup_edge(c->node, myself);
138 send_del_edge(broadcast, e);
144 /* Check if this was our outgoing connection */
147 retry_outgoing(c->outgoing);
153 Check if the other end is active.
154 If we have sent packets, but didn't receive any,
155 then possibly the other end is dead. We send a
156 PING request over the meta connection. If the other
157 end does not reply in time, we consider them dead
158 and close the connection.
160 static void timeout_handler(void *arg) {
161 event_t *event = arg;
162 splay_node_t *node, *next;
164 time_t now = time(NULL);
166 for(node = connection_tree->head; node; node = next) {
170 if(c->last_ping_time + pingtimeout < now) {
171 if(c->status.active) {
172 if(c->status.pinged) {
173 ifdebug(CONNECTIONS) logger(LOG_INFO, "%s (%s) didn't respond to PING in %ld seconds",
174 c->name, c->hostname, now - c->last_ping_time);
175 terminate_connection(c, true);
177 } else if(c->last_ping_time + pinginterval < now) {
181 if(c->status.connecting) {
183 logger(LOG_WARNING, "Timeout while connecting to %s (%s)", c->name, c->hostname);
184 c->status.connecting = false;
185 closesocket(c->socket);
186 do_outgoing_connection(c);
188 ifdebug(CONNECTIONS) logger(LOG_WARNING, "Timeout from %s (%s) during authentication", c->name, c->hostname);
189 terminate_connection(c, false);
196 if(contradicting_del_edge && contradicting_add_edge) {
197 logger(LOG_WARNING, "Possible node with same Name as us!");
199 if(rand() % 3 == 0) {
200 logger(LOG_ERR, "Shutting down, check configuration of all nodes for duplicate Names!");
205 contradicting_add_edge = 0;
206 contradicting_del_edge = 0;
209 event->time = now + pingtimeout;
213 void handle_meta_connection_data(void *data) {
214 connection_t *c = data;
216 socklen_t len = sizeof result;
218 if(c->status.connecting) {
219 c->status.connecting = false;
221 getsockopt(c->socket, SOL_SOCKET, SO_ERROR, &result, &len);
225 finish_connecting(c);
226 mutex_unlock(&mutex);
228 ifdebug(CONNECTIONS) logger(LOG_DEBUG,
229 "Error while connecting to %s (%s): %s",
230 c->name, c->hostname, sockstrerror(result));
231 closesocket(c->socket);
233 do_outgoing_connection(c);
234 mutex_unlock(&mutex);
240 if (!receive_meta(c)) {
241 terminate_connection(c, c->status.active);
247 static void sigterm_handler(int signal, short events, void *data) {
248 logger(LOG_NOTICE, "Got %s signal", strsignal(signal));
252 static void sighup_handler(int signal, short events, void *data) {
253 logger(LOG_NOTICE, "Got %s signal", strsignal(signal));
254 reload_configuration();
257 int reload_configuration(void) {
259 splay_node_t *node, *next;
262 static time_t last_config_check = 0;
264 /* Reread our own configuration file */
266 exit_configuration(&config_tree);
267 init_configuration(&config_tree);
269 if(!read_server_config()) {
270 logger(LOG_ERR, "Unable to reread configuration file, exitting.");
275 /* Close connections to hosts that have a changed or deleted host config file */
277 for(node = connection_tree->head; node; node = next) {
282 free(c->outgoing->name);
284 freeaddrinfo(c->outgoing->ai);
289 xasprintf(&fname, "%s/hosts/%s", confbase, c->name);
290 if(stat(fname, &s) || s.st_mtime > last_config_check)
291 terminate_connection(c, c->status.active);
295 last_config_check = time(NULL);
297 /* If StrictSubnet is set, expire deleted Subnets and read new ones in */
303 for(node = subnet_tree->head; node; node = node->next) {
310 for(node = subnet_tree->head; node; node = next) {
313 if(subnet->expires == 1) {
314 send_del_subnet(broadcast, subnet);
315 if(subnet->owner->status.reachable)
316 subnet_update(subnet->owner, subnet, false);
317 subnet_del(subnet->owner, subnet);
318 } else if(subnet->expires == -1) {
321 send_add_subnet(broadcast, subnet);
322 if(subnet->owner->status.reachable)
323 subnet_update(subnet->owner, subnet, true);
328 /* Try to make outgoing connections */
330 try_outgoing_connections();
339 for(node = connection_tree->head; node; node = node->next) {
342 if(c->outgoing && !c->node) {
343 event_del(&c->outgoing->ev);
344 if(c->status.connecting)
346 c->outgoing->timeout = 0;
347 do_outgoing_connection(c);
353 this is where it all happens...
355 int main_loop(void) {
356 struct event timeout_event;
358 timeout_event.time = time(NULL) + pingtimeout;
359 timeout_event.handler = timeout_handler;
360 timeout_event.data = &timeout_event;
362 event_add(&timeout_event);
365 signal(SIGHUP, sighup_handler);
368 signal(SIGTERM, sigterm_handler);
371 signal(SIGQUIT, sigterm_handler);
375 mutex_unlock(&mutex);
380 while((event = get_expired_event())) {
381 event->handler(event->data);
385 event_del(&timeout_event);