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.
27 #include "connection.h"
39 int contradicting_add_edge = 0;
40 int contradicting_del_edge = 0;
41 static int sleeptime = 10;
42 time_t last_config_check = 0;
44 /* Purge edges and subnets of unreachable nodes. Use carefully. */
47 splay_node_t *nnode, *nnext, *enode, *enext, *snode, *snext;
52 logger(DEBUG_PROTOCOL, 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 logger(DEBUG_SCARY_THINGS, LOG_DEBUG, "Purging node %s (%s)", n->name, n->hostname);
63 for(snode = n->subnet_tree->head; snode; snode = snext) {
66 send_del_subnet(everyone, s);
71 for(enode = n->edge_tree->head; enode; enode = enext) {
75 send_del_edge(everyone, e);
81 /* Check if anyone else claims to have an edge to an unreachable node. If not, delete node. */
83 for(nnode = node_tree->head; nnode; nnode = nnext) {
87 if(!n->status.reachable) {
88 for(enode = edge_weight_tree->head; enode; enode = enext) {
96 if(!enode && (!strictsubnets || !n->subnet_tree->head))
97 /* in strictsubnets mode do not delete nodes with subnets */
104 Terminate a connection:
105 - Mark it as inactive
106 - Remove the edge representing this connection
108 - Check if we need to retry making an outgoing connection
110 void terminate_connection(connection_t *c, bool report) {
111 logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Closing connection with %s (%s)", c->name, c->hostname);
113 c->status.active = false;
115 if(c->node && c->node->connection == c)
116 c->node->connection = NULL;
119 if(report && !tunnelserver)
120 send_del_edge(everyone, c->edge);
125 /* Run MST and SSSP algorithms */
129 /* If the node is not reachable anymore but we remember it had an edge to us, clean it up */
131 if(report && !c->node->status.reachable) {
133 e = lookup_edge(c->node, myself);
136 send_del_edge(everyone, e);
142 outgoing_t *outgoing = c->outgoing;
145 /* Check if this was our outgoing connection */
148 do_outgoing_connection(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 time_t now = time(NULL);
162 for(list_node_t *node = connection_list->head, *next; node; node = next) {
164 connection_t *c = node->data;
166 if(c->status.control)
169 if(c->last_ping_time + pingtimeout <= now) {
170 if(c->status.active) {
171 if(c->status.pinged) {
172 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);
173 } else if(c->last_ping_time + pinginterval <= now) {
180 if(c->status.connecting)
181 logger(DEBUG_CONNECTIONS, LOG_WARNING, "Timeout while connecting to %s (%s)", c->name, c->hostname);
183 logger(DEBUG_CONNECTIONS, LOG_WARNING, "Timeout from %s (%s) during authentication", c->name, c->hostname);
185 terminate_connection(c, c->status.active);
189 if(contradicting_del_edge > 100 && contradicting_add_edge > 100) {
190 logger(DEBUG_ALWAYS, LOG_WARNING, "Possible node with same Name as us! Sleeping %d seconds.", sleeptime);
191 usleep(sleeptime * 1000000LL);
201 contradicting_add_edge = 0;
202 contradicting_del_edge = 0;
204 event_add(event, &(struct timeval){pingtimeout, 0});
207 void handle_meta_connection_data(int fd, short events, void *data) {
208 connection_t *c = data;
210 socklen_t len = sizeof result;
212 if(c->status.connecting) {
213 c->status.connecting = false;
215 getsockopt(c->socket, SOL_SOCKET, SO_ERROR, &result, &len);
218 finish_connecting(c);
220 logger(DEBUG_CONNECTIONS, LOG_DEBUG, "Error while connecting to %s (%s): %s", c->name, c->hostname, sockstrerror(result));
221 terminate_connection(c, false);
226 if (!receive_meta(c)) {
227 terminate_connection(c, c->status.active);
232 static void sigterm_handler(int signal, short events, void *data) {
233 logger(DEBUG_ALWAYS, LOG_NOTICE, "Got %s signal", strsignal(signal));
234 event_loopexit(NULL);
237 static void sighup_handler(int signal, short events, void *data) {
238 logger(DEBUG_ALWAYS, LOG_NOTICE, "Got %s signal", strsignal(signal));
240 reload_configuration();
243 static void sigalrm_handler(int signal, short events, void *data) {
244 logger(DEBUG_ALWAYS, LOG_NOTICE, "Got %s signal", strsignal(signal));
248 int reload_configuration(void) {
251 /* Reread our own configuration file */
253 exit_configuration(&config_tree);
254 init_configuration(&config_tree);
256 if(!read_server_config()) {
257 logger(DEBUG_ALWAYS, LOG_ERR, "Unable to reread configuration file, exitting.");
258 event_loopexit(NULL);
262 read_config_options(config_tree, NULL);
264 xasprintf(&fname, "%s" SLASH "hosts" SLASH "%s", confbase, myself->name);
265 read_config_file(config_tree, fname);
268 /* Parse some options that are allowed to be changed while tinc is running */
270 setup_myself_reloadable();
272 /* If StrictSubnet is set, expire deleted Subnets and read new ones in */
275 for(splay_node_t *node = subnet_tree->head; node; node = node->next) {
276 subnet_t *subnet = node->data;
282 for(splay_node_t *node = subnet_tree->head, *next; node; node = next) {
284 subnet_t *subnet = node->data;
285 if(subnet->expires == 1) {
286 send_del_subnet(everyone, subnet);
287 if(subnet->owner->status.reachable)
288 subnet_update(subnet->owner, subnet, false);
289 subnet_del(subnet->owner, subnet);
290 } else if(subnet->expires == -1) {
293 send_add_subnet(everyone, subnet);
294 if(subnet->owner->status.reachable)
295 subnet_update(subnet->owner, subnet, true);
298 } else { /* Only read our own subnets back in */
299 for(splay_node_t *node = myself->subnet_tree->head; node; node = node->next) {
300 subnet_t *subnet = node->data;
305 config_t *cfg = lookup_config(config_tree, "Subnet");
308 subnet_t *subnet, *s2;
310 if(!get_config_subnet(cfg, &subnet))
313 if((s2 = lookup_subnet(myself, subnet))) {
319 subnet_add(myself, subnet);
320 send_add_subnet(everyone, subnet);
321 subnet_update(myself, subnet, true);
324 cfg = lookup_config_next(config_tree, cfg);
327 for(splay_node_t *node = myself->subnet_tree->head, *next; node; node = next) {
329 subnet_t *subnet = node->data;
330 if(subnet->expires == 1) {
331 send_del_subnet(everyone, subnet);
332 subnet_update(myself, subnet, false);
333 subnet_del(myself, subnet);
338 /* Try to make outgoing connections */
340 try_outgoing_connections();
342 /* Close connections to hosts that have a changed or deleted host config file */
344 for(list_node_t *node = connection_list->head, *next; node; node = next) {
345 connection_t *c = node->data;
348 if(c->status.control)
351 xasprintf(&fname, "%s" SLASH "hosts" SLASH "%s", confbase, c->name);
353 if(stat(fname, &s) || s.st_mtime > last_config_check) {
354 logger(DEBUG_CONNECTIONS, LOG_INFO, "Host config file of %s has been changed", c->name);
355 terminate_connection(c, c->status.active);
360 last_config_check = time(NULL);
366 for(list_node_t *node = connection_list->head, *next; node; node = next) {
368 connection_t *c = node->data;
370 if(c->outgoing && !c->node) {
371 if(timeout_initialized(&c->outgoing->ev))
372 event_del(&c->outgoing->ev);
373 if(c->status.connecting)
375 c->outgoing->timeout = 0;
376 terminate_connection(c, c->status.active);
382 this is where it all happens...
384 int main_loop(void) {
385 struct event timeout_event;
387 timeout_set(&timeout_event, timeout_handler, &timeout_event);
388 event_add(&timeout_event, &(struct timeval){pingtimeout, 0});
391 struct event sighup_event;
392 struct event sigterm_event;
393 struct event sigquit_event;
394 struct event sigalrm_event;
396 signal_set(&sighup_event, SIGHUP, sighup_handler, NULL);
397 signal_add(&sighup_event, NULL);
398 signal_set(&sigterm_event, SIGTERM, sigterm_handler, NULL);
399 signal_add(&sigterm_event, NULL);
400 signal_set(&sigquit_event, SIGQUIT, sigterm_handler, NULL);
401 signal_add(&sigquit_event, NULL);
402 signal_set(&sigalrm_event, SIGALRM, sigalrm_handler, NULL);
403 signal_add(&sigalrm_event, NULL);
406 if(event_loop(0) < 0) {
407 logger(DEBUG_ALWAYS, LOG_ERR, "Error while waiting for input: %s", strerror(errno));
412 signal_del(&sighup_event);
413 signal_del(&sigterm_event);
414 signal_del(&sigquit_event);
415 signal_del(&sigalrm_event);
418 event_del(&timeout_event);