2 net.c -- most of the network code
3 Copyright (C) 1998-2005 Ivo Timmermans,
4 2000-2011 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;
44 /* Purge edges and subnets of unreachable nodes. Use carefully. */
47 splay_node_t *nnode, *nnext, *enode, *enext, *snode, *snext;
52 ifdebug(PROTOCOL) logger(LOG_DEBUG, "Purging unreachable nodes");
54 /* Remove all edges and subnets owned by unreachable nodes. */
56 for(nnode = node_tree->head; nnode; nnode = nnext) {
60 if(!n->status.reachable) {
61 ifdebug(SCARY_THINGS) logger(LOG_DEBUG, "Purging node %s (%s)", n->name,
64 for(snode = n->subnet_tree->head; snode; snode = snext) {
67 send_del_subnet(broadcast, s);
72 for(enode = n->edge_tree->head; enode; enode = enext) {
76 send_del_edge(broadcast, 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:
107 - Remove associated edge and tell other connections about it if report = true
108 - Check if we need to retry making an outgoing connection
109 - Deactivate the host
111 void terminate_connection(connection_t *c, bool report) {
112 ifdebug(CONNECTIONS) logger(LOG_NOTICE, "Closing connection with %s (%s)",
113 c->name, c->hostname);
115 c->status.active = false;
118 c->node->connection = NULL;
121 if(report && !tunnelserver)
122 send_del_edge(broadcast, 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(broadcast, e);
143 /* Check if this was our outgoing connection */
146 retry_outgoing(c->outgoing);
152 Check if the other end is active.
153 If we have sent packets, but didn't receive any,
154 then possibly the other end is dead. We send a
155 PING request over the meta connection. If the other
156 end does not reply in time, we consider them dead
157 and close the connection.
159 static void timeout_handler(int fd, short events, void *event) {
160 splay_node_t *node, *next;
162 time_t now = time(NULL);
164 for(node = connection_tree->head; node; node = next) {
168 if(c->last_ping_time + pingtimeout <= now) {
169 if(c->status.active) {
170 if(c->status.pinged) {
171 ifdebug(CONNECTIONS) logger(LOG_INFO, "%s (%s) didn't respond to PING in %ld seconds",
172 c->name, c->hostname, now - c->last_ping_time);
173 terminate_connection(c, true);
175 } else if(c->last_ping_time + pinginterval <= now) {
179 if(c->status.connecting) {
181 logger(LOG_WARNING, "Timeout while connecting to %s (%s)", c->name, c->hostname);
182 c->status.connecting = false;
183 closesocket(c->socket);
184 do_outgoing_connection(c);
186 ifdebug(CONNECTIONS) logger(LOG_WARNING, "Timeout from %s (%s) during authentication", c->name, c->hostname);
187 terminate_connection(c, false);
194 if(contradicting_del_edge > 100 && contradicting_add_edge > 100) {
195 logger(LOG_WARNING, "Possible node with same Name as us! Sleeping %d seconds.", sleeptime);
206 contradicting_add_edge = 0;
207 contradicting_del_edge = 0;
209 event_add(event, &(struct timeval){pingtimeout, 0});
212 void handle_meta_connection_data(int fd, short events, void *data) {
213 connection_t *c = data;
215 socklen_t len = sizeof result;
217 if(c->status.connecting) {
218 c->status.connecting = false;
220 getsockopt(c->socket, SOL_SOCKET, SO_ERROR, &result, &len);
223 finish_connecting(c);
225 ifdebug(CONNECTIONS) logger(LOG_DEBUG,
226 "Error while connecting to %s (%s): %s",
227 c->name, c->hostname, sockstrerror(result));
228 closesocket(c->socket);
229 do_outgoing_connection(c);
234 if (!receive_meta(c)) {
235 terminate_connection(c, c->status.active);
240 static void sigterm_handler(int signal, short events, void *data) {
241 logger(LOG_NOTICE, "Got %s signal", strsignal(signal));
242 event_loopexit(NULL);
245 static void sighup_handler(int signal, short events, void *data) {
246 logger(LOG_NOTICE, "Got %s signal", strsignal(signal));
248 reload_configuration();
251 static void sigalrm_handler(int signal, short events, void *data) {
252 logger(LOG_NOTICE, "Got %s signal", strsignal(signal));
256 int reload_configuration(void) {
258 splay_node_t *node, *next;
261 static time_t last_config_check = 0;
263 /* Reread our own configuration file */
265 exit_configuration(&config_tree);
266 init_configuration(&config_tree);
268 if(!read_server_config()) {
269 logger(LOG_ERR, "Unable to reread configuration file, exitting.");
270 event_loopexit(NULL);
274 /* Close connections to hosts that have a changed or deleted host config file */
276 for(node = connection_tree->head; node; node = next) {
281 free(c->outgoing->name);
283 freeaddrinfo(c->outgoing->ai);
288 xasprintf(&fname, "%s/hosts/%s", confbase, c->name);
289 if(stat(fname, &s) || s.st_mtime > last_config_check)
290 terminate_connection(c, c->status.active);
294 last_config_check = time(NULL);
296 /* If StrictSubnet is set, expire deleted Subnets and read new ones in */
302 for(node = subnet_tree->head; node; node = node->next) {
309 for(node = subnet_tree->head; node; node = next) {
312 if(subnet->expires == 1) {
313 send_del_subnet(broadcast, subnet);
314 if(subnet->owner->status.reachable)
315 subnet_update(subnet->owner, subnet, false);
316 subnet_del(subnet->owner, subnet);
317 } else if(subnet->expires == -1) {
320 send_add_subnet(broadcast, subnet);
321 if(subnet->owner->status.reachable)
322 subnet_update(subnet->owner, subnet, true);
327 /* Try to make outgoing connections */
329 try_outgoing_connections();
338 for(node = connection_tree->head; node; node = node->next) {
341 if(c->outgoing && !c->node) {
342 if(timeout_initialized(&c->outgoing->ev))
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_set(&timeout_event, timeout_handler, &timeout_event);
359 event_add(&timeout_event, &(struct timeval){pingtimeout, 0});
362 struct event sighup_event;
363 struct event sigterm_event;
364 struct event sigquit_event;
365 struct event sigalrm_event;
367 signal_set(&sighup_event, SIGHUP, sighup_handler, NULL);
368 signal_add(&sighup_event, NULL);
369 signal_set(&sigterm_event, SIGTERM, sigterm_handler, NULL);
370 signal_add(&sigterm_event, NULL);
371 signal_set(&sigquit_event, SIGQUIT, sigterm_handler, NULL);
372 signal_add(&sigquit_event, NULL);
373 signal_set(&sigalrm_event, SIGALRM, sigalrm_handler, NULL);
374 signal_add(&sigalrm_event, NULL);
377 if(event_loop(0) < 0) {
378 logger(LOG_ERR, "Error while waiting for input: %s", strerror(errno));
383 signal_del(&sighup_event);
384 signal_del(&sigterm_event);
385 signal_del(&sigquit_event);
386 signal_del(&sigalrm_event);
389 event_del(&timeout_event);