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>
30 #include "connection.h"
42 /* Purge edges and subnets of unreachable nodes. Use carefully. */
44 static void purge(void) {
45 avl_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 put all file descriptors into events
105 While we're at it, purge stuf that needs to be removed.
107 static int build_fdset(void) {
108 avl_node_t *node, *next;
114 for(node = connection_tree->head; node; node = next) {
118 if(c->status.remove) {
120 if(!connection_tree->head)
129 Terminate a connection:
131 - Remove associated edge and tell other connections about it if report = true
132 - Check if we need to retry making an outgoing connection
133 - Deactivate the host
135 void terminate_connection(connection_t *c, bool report) {
141 ifdebug(CONNECTIONS) logger(LOG_NOTICE, _("Closing connection with %s (%s)"),
142 c->name, c->hostname);
144 c->status.remove = true;
145 c->status.active = false;
148 c->node->connection = NULL;
151 closesocket(c->socket);
156 if(report && !tunnelserver)
157 send_del_edge(broadcast, c->edge);
161 /* Run MST and SSSP algorithms */
165 /* If the node is not reachable anymore but we remember it had an edge to us, clean it up */
167 if(report && !c->node->status.reachable) {
169 e = lookup_edge(c->node, myself);
172 send_del_edge(broadcast, e);
178 /* Check if this was our outgoing connection */
181 retry_outgoing(c->outgoing);
193 Check if the other end is active.
194 If we have sent packets, but didn't receive any,
195 then possibly the other end is dead. We send a
196 PING request over the meta connection. If the other
197 end does not reply in time, we consider them dead
198 and close the connection.
200 static void timeout_handler(int fd, short events, void *event) {
201 avl_node_t *node, *next;
203 time_t now = time(NULL);
207 for(node = connection_tree->head; node; node = next) {
211 if(c->last_ping_time + pingtimeout < now) {
212 if(c->status.active) {
213 if(c->status.pinged) {
214 ifdebug(CONNECTIONS) logger(LOG_INFO, _("%s (%s) didn't respond to PING in %ld seconds"),
215 c->name, c->hostname, now - c->last_ping_time);
216 c->status.timeout = true;
217 terminate_connection(c, true);
218 } else if(c->last_ping_time + pinginterval < now) {
222 if(c->status.remove) {
223 logger(LOG_WARNING, _("Old connection_t for %s (%s) status %04x still lingering, deleting..."),
224 c->name, c->hostname, c->status.value);
228 ifdebug(CONNECTIONS) logger(LOG_WARNING, _("Timeout from %s (%s) during authentication"),
229 c->name, c->hostname);
230 if(c->status.connecting) {
231 c->status.connecting = false;
232 closesocket(c->socket);
233 do_outgoing_connection(c);
235 terminate_connection(c, false);
241 event_add(event, &(struct timeval){pingtimeout, 0});
244 void handle_meta_connection_data(int fd, short events, void *data) {
245 connection_t *c = data;
247 socklen_t len = sizeof(result);
249 if (c->status.remove)
252 if(c->status.connecting) {
253 getsockopt(c->socket, SOL_SOCKET, SO_ERROR, &result, &len);
256 finish_connecting(c);
258 ifdebug(CONNECTIONS) logger(LOG_DEBUG,
259 _("Error while connecting to %s (%s): %s"),
260 c->name, c->hostname, strerror(result));
261 c->status.connecting = false;
262 closesocket(c->socket);
263 do_outgoing_connection(c);
268 if (!receive_meta(c)) {
269 terminate_connection(c, c->status.active);
274 static void sigterm_handler(int signal, short events, void *data) {
275 logger(LOG_NOTICE, _("Got %s signal"), strsignal(signal));
276 event_loopexit(NULL);
279 static void sigint_handler(int signal, short events, void *data) {
280 static int saved_debug_level = -1;
282 logger(LOG_NOTICE, _("Got %s signal"), strsignal(signal));
284 if(saved_debug_level != -1) {
285 logger(LOG_NOTICE, _("Reverting to old debug level (%d)"),
287 debug_level = saved_debug_level;
288 saved_debug_level = -1;
291 _("Temporarily setting debug level to 5. Kill me with SIGINT again to go back to level %d."),
293 saved_debug_level = debug_level;
298 static void sigusr1_handler(int signal, short events, void *data) {
299 logger(LOG_NOTICE, _("Got %s signal"), strsignal(signal));
303 static void sigusr2_handler(int signal, short events, void *data) {
304 logger(LOG_NOTICE, _("Got %s signal"), strsignal(signal));
311 static void sigwinch_handler(int signal, short events, void *data) {
312 logger(LOG_NOTICE, _("Got %s signal"), strsignal(signal));
316 static void sighup_handler(int signal, short events, void *data) {
321 static time_t last_config_check = 0;
323 logger(LOG_NOTICE, _("Got %s signal"), strsignal(signal));
325 /* Reread our own configuration file */
327 exit_configuration(&config_tree);
328 init_configuration(&config_tree);
330 if(!read_server_config()) {
331 logger(LOG_ERR, _("Unable to reread configuration file, exitting."));
332 event_loopexit(NULL);
336 /* Close connections to hosts that have a changed or deleted host config file */
338 for(node = connection_tree->head; node; node = node->next) {
342 free(c->outgoing->name);
344 freeaddrinfo(c->outgoing->ai);
349 asprintf(&fname, "%s/hosts/%s", confbase, c->name);
350 if(stat(fname, &s) || s.st_mtime > last_config_check)
351 terminate_connection(c, c->status.active);
355 last_config_check = time(NULL);
357 /* Try to make outgoing connections */
359 try_outgoing_connections();
362 static void sigalrm_handler(int signal, short events, void *data) {
363 logger(LOG_NOTICE, _("Got %s signal"), strsignal(signal));
368 for(node = connection_tree->head; node; node = node->next) {
371 if(c->outgoing && !c->node) {
372 if(timeout_initialized(&c->outgoing->ev))
373 event_del(&c->outgoing->ev);
374 if(c->status.connecting)
376 c->outgoing->timeout = 0;
377 do_outgoing_connection(c);
383 this is where it all happens...
385 int main_loop(void) {
388 struct event timeout_event;
389 struct event sighup_event;
390 struct event sigint_event;
391 struct event sigterm_event;
392 struct event sigquit_event;
393 struct event sigusr1_event;
394 struct event sigusr2_event;
395 struct event sigwinch_event;
396 struct event sigalrm_event;
400 timeout_set(&timeout_event, timeout_handler, &timeout_event);
401 event_add(&timeout_event, &(struct timeval){pingtimeout, 0});
402 signal_set(&sighup_event, SIGHUP, sighup_handler, NULL);
403 signal_add(&sighup_event, NULL);
404 signal_set(&sigint_event, SIGINT, sigint_handler, NULL);
405 signal_add(&sigint_event, NULL);
406 signal_set(&sigterm_event, SIGTERM, sigterm_handler, NULL);
407 signal_add(&sigterm_event, NULL);
408 signal_set(&sigquit_event, SIGQUIT, sigterm_handler, NULL);
409 signal_add(&sigquit_event, NULL);
410 signal_set(&sigusr1_event, SIGUSR1, sigusr1_handler, NULL);
411 signal_add(&sigusr1_event, NULL);
412 signal_set(&sigusr2_event, SIGUSR2, sigusr2_handler, NULL);
413 signal_add(&sigusr2_event, NULL);
414 signal_set(&sigwinch_event, SIGWINCH, sigwinch_handler, NULL);
415 signal_add(&sigwinch_event, NULL);
416 signal_set(&sigalrm_event, SIGALRM, sigalrm_handler, NULL);
417 signal_add(&sigalrm_event, NULL);
419 if(event_loop(0) < 0) {
420 logger(LOG_ERR, _("Error while waiting for input: %s"), strerror(errno));
424 signal_del(&sighup_event);
425 signal_del(&sigint_event);
426 signal_del(&sigterm_event);
427 signal_del(&sigquit_event);
428 signal_del(&sigusr1_event);
429 signal_del(&sigusr2_event);
430 signal_del(&sigwinch_event);
431 signal_del(&sigalrm_event);
432 event_del(&timeout_event);