2 net.c -- most of the network code
3 Copyright (C) 1998-2005 Ivo Timmermans,
4 2000-2012 Guus Sliepen <guus@tinc-vpn.org>
5 2006 Scott Lamb <slamb@slamb.org>
6 2011 Loïc Grenié <loic.grenie@gmail.com>
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License along
19 with this program; if not, write to the Free Software Foundation, Inc.,
20 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
26 #include "splay_tree.h"
28 #include "connection.h"
40 int contradicting_add_edge = 0;
41 int contradicting_del_edge = 0;
42 static int sleeptime = 10;
43 time_t last_config_check = 0;
45 /* Purge edges and subnets of unreachable nodes. Use carefully. */
48 splay_node_t *nnode, *nnext, *enode, *enext, *snode, *snext;
53 logger(DEBUG_PROTOCOL, LOG_DEBUG, "Purging unreachable nodes");
55 /* Remove all edges and subnets owned by unreachable nodes. */
57 for(nnode = node_tree->head; nnode; nnode = nnext) {
61 if(!n->status.reachable) {
62 logger(DEBUG_SCARY_THINGS, LOG_DEBUG, "Purging node %s (%s)", n->name, n->hostname);
64 for(snode = n->subnet_tree->head; snode; snode = snext) {
67 send_del_subnet(everyone, s);
72 for(enode = n->edge_tree->head; enode; enode = enext) {
76 send_del_edge(everyone, e);
82 /* Check if anyone else claims to have an edge to an unreachable node. If not, delete node. */
84 for(nnode = node_tree->head; nnode; nnode = nnext) {
88 if(!n->status.reachable) {
89 for(enode = edge_weight_tree->head; enode; enode = enext) {
97 if(!enode && (!strictsubnets || !n->subnet_tree->head))
98 /* in strictsubnets mode do not delete nodes with subnets */
105 Terminate a connection:
106 - Mark it as inactive
107 - Remove the edge representing this connection
109 - Check if we need to retry making an outgoing connection
111 void terminate_connection(connection_t *c, bool report) {
112 logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Closing connection with %s (%s)", c->name, c->hostname);
114 c->status.active = false;
116 if(c->node && c->node->connection == c)
117 c->node->connection = NULL;
120 if(report && !tunnelserver)
121 send_del_edge(everyone, c->edge);
126 /* Run MST and SSSP algorithms */
130 /* If the node is not reachable anymore but we remember it had an edge to us, clean it up */
132 if(report && !c->node->status.reachable) {
134 e = lookup_edge(c->node, myself);
137 send_del_edge(everyone, e);
143 outgoing_t *outgoing = c->outgoing;
146 /* Check if this was our outgoing connection */
149 do_outgoing_connection(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(int fd, short events, void *event) {
161 splay_node_t *node, *next;
163 time_t now = time(NULL);
165 for(node = connection_tree->head; node; node = next) {
169 if(c->status.control)
172 if(c->last_ping_time + pingtimeout <= now) {
173 if(c->status.active) {
174 if(c->status.pinged) {
175 logger(DEBUG_CONNECTIONS, LOG_INFO, "%s (%s) didn't respond to PING in %ld seconds", c->name, c->hostname, (long)now - c->last_ping_time);
176 } else if(c->last_ping_time + pinginterval <= now) {
183 if(c->status.connecting)
184 logger(DEBUG_CONNECTIONS, LOG_WARNING, "Timeout while connecting to %s (%s)", c->name, c->hostname);
186 logger(DEBUG_CONNECTIONS, LOG_WARNING, "Timeout from %s (%s) during authentication", c->name, c->hostname);
188 terminate_connection(c, c->status.active);
192 if(contradicting_del_edge > 100 && contradicting_add_edge > 100) {
193 logger(DEBUG_ALWAYS, LOG_WARNING, "Possible node with same Name as us! Sleeping %d seconds.", sleeptime);
194 usleep(sleeptime * 1000000LL);
204 contradicting_add_edge = 0;
205 contradicting_del_edge = 0;
207 event_add(event, &(struct timeval){pingtimeout, 0});
210 void handle_meta_connection_data(int fd, short events, void *data) {
211 connection_t *c = data;
213 socklen_t len = sizeof result;
215 if(c->status.connecting) {
216 c->status.connecting = false;
218 getsockopt(c->socket, SOL_SOCKET, SO_ERROR, &result, &len);
221 finish_connecting(c);
223 logger(DEBUG_CONNECTIONS, LOG_DEBUG, "Error while connecting to %s (%s): %s", c->name, c->hostname, sockstrerror(result));
224 terminate_connection(c, false);
229 if (!receive_meta(c)) {
230 terminate_connection(c, c->status.active);
235 static void sigterm_handler(int signal, short events, void *data) {
236 logger(DEBUG_ALWAYS, LOG_NOTICE, "Got %s signal", strsignal(signal));
237 event_loopexit(NULL);
240 static void sighup_handler(int signal, short events, void *data) {
241 logger(DEBUG_ALWAYS, LOG_NOTICE, "Got %s signal", strsignal(signal));
243 reload_configuration();
246 static void sigalrm_handler(int signal, short events, void *data) {
247 logger(DEBUG_ALWAYS, LOG_NOTICE, "Got %s signal", strsignal(signal));
251 int reload_configuration(void) {
253 splay_node_t *node, *next;
257 /* Reread our own configuration file */
259 exit_configuration(&config_tree);
260 init_configuration(&config_tree);
262 if(!read_server_config()) {
263 logger(DEBUG_ALWAYS, LOG_ERR, "Unable to reread configuration file, exitting.");
264 event_loopexit(NULL);
268 read_config_options(config_tree, NULL);
270 xasprintf(&fname, "%s" SLASH "hosts" SLASH "%s", confbase, myself->name);
271 read_config_file(config_tree, fname);
274 /* Parse some options that are allowed to be changed while tinc is running */
276 setup_myself_reloadable();
278 /* If StrictSubnet is set, expire deleted Subnets and read new ones in */
283 for(node = subnet_tree->head; node; node = node->next) {
290 for(node = subnet_tree->head; node; node = next) {
293 if(subnet->expires == 1) {
294 send_del_subnet(everyone, subnet);
295 if(subnet->owner->status.reachable)
296 subnet_update(subnet->owner, subnet, false);
297 subnet_del(subnet->owner, subnet);
298 } else if(subnet->expires == -1) {
301 send_add_subnet(everyone, subnet);
302 if(subnet->owner->status.reachable)
303 subnet_update(subnet->owner, subnet, true);
306 } else { /* Only read our own subnets back in */
307 subnet_t *subnet, *s2;
309 for(node = myself->subnet_tree->head; node; node = node->next) {
310 subnet_t *subnet = node->data;
315 config_t *cfg = lookup_config(config_tree, "Subnet");
318 if(!get_config_subnet(cfg, &subnet))
321 if((s2 = lookup_subnet(myself, subnet))) {
327 subnet_add(myself, subnet);
328 send_add_subnet(everyone, subnet);
329 subnet_update(myself, subnet, true);
332 cfg = lookup_config_next(config_tree, cfg);
335 for(node = myself->subnet_tree->head; node; node = next) {
337 subnet_t *subnet = node->data;
338 if(subnet->expires == 1) {
339 send_del_subnet(everyone, subnet);
340 subnet_update(myself, subnet, false);
341 subnet_del(myself, subnet);
346 /* Try to make outgoing connections */
348 try_outgoing_connections();
350 /* Close connections to hosts that have a changed or deleted host config file */
352 for(node = connection_tree->head; node; node = next) {
356 if(c->status.control)
359 xasprintf(&fname, "%s" SLASH "hosts" SLASH "%s", confbase, c->name);
360 if(stat(fname, &s) || s.st_mtime > last_config_check) {
361 logger(DEBUG_CONNECTIONS, LOG_INFO, "Host config file of %s has been changed", c->name);
362 terminate_connection(c, c->status.active);
367 last_config_check = time(NULL);
374 splay_node_t *node, *next;
376 for(node = connection_tree->head; node; node = next) {
380 if(c->outgoing && !c->node) {
381 if(timeout_initialized(&c->outgoing->ev))
382 event_del(&c->outgoing->ev);
383 if(c->status.connecting)
385 c->outgoing->timeout = 0;
386 terminate_connection(c, c->status.active);
392 this is where it all happens...
394 int main_loop(void) {
395 struct event timeout_event;
397 timeout_set(&timeout_event, timeout_handler, &timeout_event);
398 event_add(&timeout_event, &(struct timeval){pingtimeout, 0});
401 struct event sighup_event;
402 struct event sigterm_event;
403 struct event sigquit_event;
404 struct event sigalrm_event;
406 signal_set(&sighup_event, SIGHUP, sighup_handler, NULL);
407 signal_add(&sighup_event, NULL);
408 signal_set(&sigterm_event, SIGTERM, sigterm_handler, NULL);
409 signal_add(&sigterm_event, NULL);
410 signal_set(&sigquit_event, SIGQUIT, sigterm_handler, NULL);
411 signal_add(&sigquit_event, NULL);
412 signal_set(&sigalrm_event, SIGALRM, sigalrm_handler, NULL);
413 signal_add(&sigalrm_event, NULL);
416 if(event_loop(0) < 0) {
417 logger(DEBUG_ALWAYS, LOG_ERR, "Error while waiting for input: %s", strerror(errno));
422 signal_del(&sighup_event);
423 signal_del(&sigterm_event);
424 signal_del(&sigquit_event);
425 signal_del(&sigalrm_event);
428 event_del(&timeout_event);