2 net.c -- most of the network code
3 Copyright (C) 1998-2005 Ivo Timmermans,
4 2000-2013 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;
43 static timeout_t pingtimer;
44 static timeout_t periodictimer;
46 /* Purge edges and subnets of unreachable nodes. Use carefully. */
49 logger(DEBUG_PROTOCOL, LOG_DEBUG, "Purging unreachable nodes");
51 /* Remove all edges and subnets owned by unreachable nodes. */
53 for splay_each(node_t, n, node_tree) {
54 if(!n->status.reachable) {
55 logger(DEBUG_SCARY_THINGS, LOG_DEBUG, "Purging node %s (%s)", n->name, n->hostname);
57 for splay_each(subnet_t, s, n->subnet_tree) {
58 send_del_subnet(everyone, s);
63 for splay_each(edge_t, e, n->edge_tree) {
65 send_del_edge(everyone, e);
71 /* Check if anyone else claims to have an edge to an unreachable node. If not, delete node. */
73 for splay_each(node_t, n, node_tree) {
74 if(!n->status.reachable) {
75 for splay_each(edge_t, e, edge_weight_tree)
79 if(!autoconnect && (!strictsubnets || !n->subnet_tree->head))
80 /* in strictsubnets mode do not delete nodes with subnets */
87 Terminate a connection:
89 - Remove the edge representing this connection
91 - Check if we need to retry making an outgoing connection
93 void terminate_connection(connection_t *c, bool report) {
94 logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Closing connection with %s (%s)", c->name, c->hostname);
96 c->status.active = false;
98 if(c->node && c->node->connection == c)
99 c->node->connection = NULL;
102 if(report && !tunnelserver)
103 send_del_edge(everyone, c->edge);
108 /* Run MST and SSSP algorithms */
112 /* If the node is not reachable anymore but we remember it had an edge to us, clean it up */
114 if(report && !c->node->status.reachable) {
116 e = lookup_edge(c->node, myself);
119 send_del_edge(everyone, e);
125 outgoing_t *outgoing = c->outgoing;
128 /* Check if this was our outgoing connection */
131 do_outgoing_connection(outgoing);
135 Check if the other end is active.
136 If we have sent packets, but didn't receive any,
137 then possibly the other end is dead. We send a
138 PING request over the meta connection. If the other
139 end does not reply in time, we consider them dead
140 and close the connection.
142 static void timeout_handler(void *data) {
143 for list_each(connection_t, c, connection_list) {
144 if(c->status.control)
147 if(c->last_ping_time + pingtimeout <= now.tv_sec) {
148 if(c->status.active) {
149 if(c->status.pinged) {
150 logger(DEBUG_CONNECTIONS, LOG_INFO, "%s (%s) didn't respond to PING in %ld seconds", c->name, c->hostname, (long)now.tv_sec - c->last_ping_time);
151 } else if(c->last_ping_time + pinginterval <= now.tv_sec) {
158 if(c->status.connecting)
159 logger(DEBUG_CONNECTIONS, LOG_WARNING, "Timeout while connecting to %s (%s)", c->name, c->hostname);
161 logger(DEBUG_CONNECTIONS, LOG_WARNING, "Timeout from %s (%s) during authentication", c->name, c->hostname);
163 terminate_connection(c, c->status.active);
167 timeout_set(data, &(struct timeval){pingtimeout, rand() % 100000});
170 static void periodic_handler(void *data) {
171 /* Check if there are too many contradicting ADD_EDGE and DEL_EDGE messages.
172 This usually only happens when another node has the same Name as this node.
173 If so, sleep for a short while to prevent a storm of contradicting messages.
176 if(contradicting_del_edge > 100 && contradicting_add_edge > 100) {
177 logger(DEBUG_ALWAYS, LOG_WARNING, "Possible node with same Name as us! Sleeping %d seconds.", sleeptime);
178 usleep(sleeptime * 1000000LL);
188 contradicting_add_edge = 0;
189 contradicting_del_edge = 0;
191 /* If AutoConnect is set, check if we need to make or break connections. */
193 if(autoconnect && node_tree->count > 1) {
194 /* Count number of active connections */
196 for list_each(connection_t, c, connection_list) {
197 if(c->status.active && !c->status.control)
201 if(nc < autoconnect) {
202 /* Not enough active connections, try to add one.
203 Choose a random node, if we don't have a connection to it,
204 and we are not already trying to make one, create an
205 outgoing connection to this node.
207 int r = rand() % node_tree->count;
210 for splay_each(node_t, n, node_tree) {
219 for list_each(outgoing_t, outgoing, outgoing_list) {
220 if(!strcmp(outgoing->name, n->name)) {
227 logger(DEBUG_CONNECTIONS, LOG_INFO, "Autoconnecting to %s", n->name);
228 outgoing_t *outgoing = xzalloc(sizeof *outgoing);
229 outgoing->name = xstrdup(n->name);
230 list_insert_tail(outgoing_list, outgoing);
231 setup_outgoing_connection(outgoing);
235 } else if(nc > autoconnect) {
236 /* Too many active connections, try to remove one.
237 Choose a random outgoing connection to a node
238 that has at least one other connection.
243 for list_each(connection_t, c, connection_list) {
244 if(!c->status.active || c->status.control)
250 if(!c->outgoing || !c->node || c->node->edge_tree->count < 2)
253 logger(DEBUG_CONNECTIONS, LOG_INFO, "Autodisconnecting from %s", c->name);
254 list_delete(outgoing_list, c->outgoing);
256 terminate_connection(c, c->status.active);
261 if(nc >= autoconnect) {
262 /* If we have enough active connections,
263 remove any pending outgoing connections.
265 for list_each(outgoing_t, o, outgoing_list) {
267 for list_each(connection_t, c, connection_list) {
268 if(c->outgoing == o) {
274 logger(DEBUG_CONNECTIONS, LOG_INFO, "Cancelled outgoing connection to %s", o->name);
275 list_delete_node(outgoing_list, node);
281 timeout_set(data, &(struct timeval){5, rand() % 100000});
284 void handle_meta_connection_data(connection_t *c) {
285 if (!receive_meta(c)) {
286 terminate_connection(c, c->status.active);
292 static void sigterm_handler(void *data) {
293 logger(DEBUG_ALWAYS, LOG_NOTICE, "Got %s signal", strsignal(((signal_t *)data)->signum));
297 static void sighup_handler(void *data) {
298 logger(DEBUG_ALWAYS, LOG_NOTICE, "Got %s signal", strsignal(((signal_t *)data)->signum));
300 if(reload_configuration())
304 static void sigalrm_handler(void *data) {
305 logger(DEBUG_ALWAYS, LOG_NOTICE, "Got %s signal", strsignal(((signal_t *)data)->signum));
310 int reload_configuration(void) {
313 /* Reread our own configuration file */
315 exit_configuration(&config_tree);
316 init_configuration(&config_tree);
318 if(!read_server_config()) {
319 logger(DEBUG_ALWAYS, LOG_ERR, "Unable to reread configuration file.");
323 read_config_options(config_tree, NULL);
325 xasprintf(&fname, "%s" SLASH "hosts" SLASH "%s", confbase, myself->name);
326 read_config_file(config_tree, fname);
329 /* Parse some options that are allowed to be changed while tinc is running */
331 setup_myself_reloadable();
333 /* If StrictSubnet is set, expire deleted Subnets and read new ones in */
336 for splay_each(subnet_t, subnet, subnet_tree)
341 for splay_each(subnet_t, subnet, subnet_tree) {
342 if(subnet->expires == 1) {
343 send_del_subnet(everyone, subnet);
344 if(subnet->owner->status.reachable)
345 subnet_update(subnet->owner, subnet, false);
346 subnet_del(subnet->owner, subnet);
347 } else if(subnet->expires == -1) {
350 send_add_subnet(everyone, subnet);
351 if(subnet->owner->status.reachable)
352 subnet_update(subnet->owner, subnet, true);
355 } else { /* Only read our own subnets back in */
356 for splay_each(subnet_t, subnet, myself->subnet_tree)
360 config_t *cfg = lookup_config(config_tree, "Subnet");
363 subnet_t *subnet, *s2;
365 if(!get_config_subnet(cfg, &subnet))
368 if((s2 = lookup_subnet(myself, subnet))) {
374 subnet_add(myself, subnet);
375 send_add_subnet(everyone, subnet);
376 subnet_update(myself, subnet, true);
379 cfg = lookup_config_next(config_tree, cfg);
382 for splay_each(subnet_t, subnet, myself->subnet_tree) {
383 if(subnet->expires == 1) {
384 send_del_subnet(everyone, subnet);
385 subnet_update(myself, subnet, false);
386 subnet_del(myself, subnet);
391 /* Try to make outgoing connections */
393 try_outgoing_connections();
395 /* Close connections to hosts that have a changed or deleted host config file */
397 for list_each(connection_t, c, connection_list) {
398 if(c->status.control)
401 xasprintf(&fname, "%s" SLASH "hosts" SLASH "%s", confbase, c->name);
403 if(stat(fname, &s) || s.st_mtime > last_config_check) {
404 logger(DEBUG_CONNECTIONS, LOG_INFO, "Host config file of %s has been changed", c->name);
405 terminate_connection(c, c->status.active);
410 last_config_check = now.tv_sec;
416 /* Reset the reconnection timers for all outgoing connections */
417 for list_each(outgoing_t, outgoing, outgoing_list) {
418 outgoing->timeout = 0;
420 timeout_set(&outgoing->ev, &(struct timeval){0, 0});
423 /* Check for outgoing connections that are in progress, and reset their ping timers */
424 for list_each(connection_t, c, connection_list) {
425 if(c->outgoing && !c->node)
426 c->last_ping_time = 0;
429 /* Kick the ping timeout handler */
430 timeout_set(&pingtimer, &(struct timeval){0, 0});
434 this is where it all happens...
436 int main_loop(void) {
437 timeout_add(&pingtimer, timeout_handler, &pingtimer, &(struct timeval){pingtimeout, rand() % 100000});
438 timeout_add(&periodictimer, periodic_handler, &periodictimer, &(struct timeval){pingtimeout, rand() % 100000});
441 signal_t sighup = {0};
442 signal_t sigterm = {0};
443 signal_t sigquit = {0};
444 signal_t sigint = {0};
445 signal_t sigalrm = {0};
447 signal_add(&sighup, sighup_handler, &sighup, SIGHUP);
448 signal_add(&sigterm, sigterm_handler, &sigterm, SIGTERM);
449 signal_add(&sigquit, sigterm_handler, &sigquit, SIGQUIT);
450 signal_add(&sigint, sigterm_handler, &sigint, SIGINT);
451 signal_add(&sigalrm, sigalrm_handler, &sigalrm, SIGALRM);
455 logger(DEBUG_ALWAYS, LOG_ERR, "Error while waiting for input: %s", strerror(errno));
461 signal_del(&sigterm);
462 signal_del(&sigquit);
464 signal_del(&sigalrm);
467 timeout_del(&periodictimer);
468 timeout_del(&pingtimer);