2 net.c -- most of the network code
3 Copyright (C) 1998-2005 Ivo Timmermans,
4 2000-2006 Guus Sliepen <guus@tinc-vpn.org>
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
25 #include <openssl/rand.h>
28 #include "splay_tree.h"
30 #include "connection.h"
42 /* Purge edges and subnets of unreachable nodes. Use carefully. */
44 static void purge(void) {
45 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) {
68 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) {
104 Terminate a connection:
106 - Remove associated edge and tell other connections about it if report = true
107 - Check if we need to retry making an outgoing connection
108 - Deactivate the host
110 void terminate_connection(connection_t *c, bool report) {
113 ifdebug(CONNECTIONS) logger(LOG_NOTICE, _("Closing connection with %s (%s)"),
114 c->name, c->hostname);
116 c->status.active = false;
119 c->node->connection = NULL;
122 closesocket(c->socket);
127 if(report && !tunnelserver)
128 send_del_edge(broadcast, c->edge);
132 /* Run MST and SSSP algorithms */
136 /* If the node is not reachable anymore but we remember it had an edge to us, clean it up */
138 if(report && !c->node->status.reachable) {
140 e = lookup_edge(c->node, myself);
143 send_del_edge(broadcast, e);
155 /* Check if this was our outgoing connection */
158 retry_outgoing(c->outgoing);
164 Check if the other end is active.
165 If we have sent packets, but didn't receive any,
166 then possibly the other end is dead. We send a
167 PING request over the meta connection. If the other
168 end does not reply in time, we consider them dead
169 and close the connection.
171 static void timeout_handler(int fd, short events, void *event) {
172 splay_node_t *node, *next;
174 time_t now = time(NULL);
178 for(node = connection_tree->head; node; node = next) {
182 if(c->last_ping_time + pingtimeout < now) {
183 if(c->status.active) {
184 if(c->status.pinged) {
185 ifdebug(CONNECTIONS) logger(LOG_INFO, _("%s (%s) didn't respond to PING in %ld seconds"),
186 c->name, c->hostname, now - c->last_ping_time);
187 terminate_connection(c, true);
189 } else if(c->last_ping_time + pinginterval < now) {
193 if(c->status.connecting) {
195 logger(LOG_WARNING, _("Timeout while connecting to %s (%s)"), c->name, c->hostname);
196 c->status.connecting = false;
197 closesocket(c->socket);
198 do_outgoing_connection(c);
200 ifdebug(CONNECTIONS) logger(LOG_WARNING, _("Timeout from %s (%s) during authentication"), c->name, c->hostname);
201 terminate_connection(c, false);
208 event_add(event, &(struct timeval){pingtimeout, 0});
211 void handle_meta_connection_data(int fd, short events, void *data) {
212 connection_t *c = data;
214 socklen_t len = sizeof(result);
216 if(c->status.connecting) {
217 c->status.connecting = false;
219 getsockopt(c->socket, SOL_SOCKET, SO_ERROR, &result, &len);
222 finish_connecting(c);
224 ifdebug(CONNECTIONS) logger(LOG_DEBUG,
225 _("Error while connecting to %s (%s): %s"),
226 c->name, c->hostname, strerror(result));
227 closesocket(c->socket);
228 do_outgoing_connection(c);
233 if (!receive_meta(c)) {
234 terminate_connection(c, c->status.active);
239 static void sigterm_handler(int signal, short events, void *data) {
240 logger(LOG_NOTICE, _("Got %s signal"), strsignal(signal));
241 event_loopexit(NULL);
244 static void sigint_handler(int signal, short events, void *data) {
245 static int saved_debug_level = -1;
247 logger(LOG_NOTICE, _("Got %s signal"), strsignal(signal));
249 if(saved_debug_level != -1) {
250 logger(LOG_NOTICE, _("Reverting to old debug level (%d)"),
252 debug_level = saved_debug_level;
253 saved_debug_level = -1;
256 _("Temporarily setting debug level to 5. Kill me with SIGINT again to go back to level %d."),
258 saved_debug_level = debug_level;
263 static void sigusr1_handler(int signal, short events, void *data) {
264 logger(LOG_NOTICE, _("Got %s signal"), strsignal(signal));
268 static void sigusr2_handler(int signal, short events, void *data) {
269 logger(LOG_NOTICE, _("Got %s signal"), strsignal(signal));
276 static void sigwinch_handler(int signal, short events, void *data) {
277 logger(LOG_NOTICE, _("Got %s signal"), strsignal(signal));
281 static void sighup_handler(int signal, short events, void *data) {
286 static time_t last_config_check = 0;
288 logger(LOG_NOTICE, _("Got %s signal"), strsignal(signal));
290 /* Reread our own configuration file */
292 exit_configuration(&config_tree);
293 init_configuration(&config_tree);
295 if(!read_server_config()) {
296 logger(LOG_ERR, _("Unable to reread configuration file, exitting."));
297 event_loopexit(NULL);
301 /* Close connections to hosts that have a changed or deleted host config file */
303 for(node = connection_tree->head; node; node = node->next) {
307 free(c->outgoing->name);
309 freeaddrinfo(c->outgoing->ai);
314 asprintf(&fname, "%s/hosts/%s", confbase, c->name);
315 if(stat(fname, &s) || s.st_mtime > last_config_check)
316 terminate_connection(c, c->status.active);
320 last_config_check = time(NULL);
322 /* Try to make outgoing connections */
324 try_outgoing_connections();
327 static void sigalrm_handler(int signal, short events, void *data) {
328 logger(LOG_NOTICE, _("Got %s signal"), strsignal(signal));
333 for(node = connection_tree->head; node; node = node->next) {
336 if(c->outgoing && !c->node) {
337 if(timeout_initialized(&c->outgoing->ev))
338 event_del(&c->outgoing->ev);
339 if(c->status.connecting)
341 c->outgoing->timeout = 0;
342 do_outgoing_connection(c);
348 this is where it all happens...
350 int main_loop(void) {
351 struct event timeout_event;
352 struct event sighup_event;
353 struct event sigint_event;
354 struct event sigterm_event;
355 struct event sigquit_event;
356 struct event sigusr1_event;
357 struct event sigusr2_event;
358 struct event sigwinch_event;
359 struct event sigalrm_event;
363 timeout_set(&timeout_event, timeout_handler, &timeout_event);
364 event_add(&timeout_event, &(struct timeval){pingtimeout, 0});
365 signal_set(&sighup_event, SIGHUP, sighup_handler, NULL);
366 signal_add(&sighup_event, NULL);
367 signal_set(&sigint_event, SIGINT, sigint_handler, NULL);
368 signal_add(&sigint_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(&sigusr1_event, SIGUSR1, sigusr1_handler, NULL);
374 signal_add(&sigusr1_event, NULL);
375 signal_set(&sigusr2_event, SIGUSR2, sigusr2_handler, NULL);
376 signal_add(&sigusr2_event, NULL);
377 signal_set(&sigwinch_event, SIGWINCH, sigwinch_handler, NULL);
378 signal_add(&sigwinch_event, NULL);
379 signal_set(&sigalrm_event, SIGALRM, sigalrm_handler, NULL);
380 signal_add(&sigalrm_event, NULL);
382 if(event_loop(0) < 0) {
383 logger(LOG_ERR, _("Error while waiting for input: %s"), strerror(errno));
387 signal_del(&sighup_event);
388 signal_del(&sigint_event);
389 signal_del(&sigterm_event);
390 signal_del(&sigquit_event);
391 signal_del(&sigusr1_event);
392 signal_del(&sigusr2_event);
393 signal_del(&sigwinch_event);
394 signal_del(&sigalrm_event);
395 event_del(&timeout_event);