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;
43 /* Purge edges and subnets of unreachable nodes. Use carefully. */
46 splay_node_t *nnode, *nnext, *enode, *enext, *snode, *snext;
51 ifdebug(PROTOCOL) logger(LOG_DEBUG, "Purging unreachable nodes");
53 /* Remove all edges and subnets owned by unreachable nodes. */
55 for(nnode = node_tree->head; nnode; nnode = nnext) {
59 if(!n->status.reachable) {
60 ifdebug(SCARY_THINGS) logger(LOG_DEBUG, "Purging node %s (%s)", n->name,
63 for(snode = n->subnet_tree->head; snode; snode = snext) {
66 send_del_subnet(broadcast, s);
71 for(enode = n->edge_tree->head; enode; enode = enext) {
75 send_del_edge(broadcast, 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:
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) {
111 ifdebug(CONNECTIONS) logger(LOG_NOTICE, "Closing connection with %s (%s)",
112 c->name, c->hostname);
114 c->status.active = false;
117 c->node->connection = NULL;
120 if(report && !tunnelserver)
121 send_del_edge(broadcast, 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(broadcast, e);
142 /* Check if this was our outgoing connection */
145 retry_outgoing(c->outgoing);
151 Check if the other end is active.
152 If we have sent packets, but didn't receive any,
153 then possibly the other end is dead. We send a
154 PING request over the meta connection. If the other
155 end does not reply in time, we consider them dead
156 and close the connection.
158 static void timeout_handler(int fd, short events, void *event) {
159 splay_node_t *node, *next;
161 time_t now = time(NULL);
163 for(node = connection_tree->head; node; node = next) {
167 if(c->last_ping_time + pingtimeout <= now) {
168 if(c->status.active) {
169 if(c->status.pinged) {
170 ifdebug(CONNECTIONS) logger(LOG_INFO, "%s (%s) didn't respond to PING in %ld seconds",
171 c->name, c->hostname, now - c->last_ping_time);
172 terminate_connection(c, true);
174 } else if(c->last_ping_time + pinginterval <= now) {
178 if(c->status.connecting) {
180 logger(LOG_WARNING, "Timeout while connecting to %s (%s)", c->name, c->hostname);
181 c->status.connecting = false;
182 closesocket(c->socket);
183 do_outgoing_connection(c);
185 ifdebug(CONNECTIONS) logger(LOG_WARNING, "Timeout from %s (%s) during authentication", c->name, c->hostname);
186 terminate_connection(c, false);
193 if(contradicting_del_edge && contradicting_add_edge) {
194 logger(LOG_WARNING, "Possible node with same Name as us!");
196 if(rand() % 3 == 0) {
197 logger(LOG_ERR, "Shutting down, check configuration of all nodes for duplicate Names!");
198 event_loopexit(NULL);
202 contradicting_add_edge = 0;
203 contradicting_del_edge = 0;
206 event_add(event, &(struct timeval){pingtimeout, 0});
209 void handle_meta_connection_data(int fd, short events, void *data) {
210 connection_t *c = data;
212 socklen_t len = sizeof result;
214 if(c->status.connecting) {
215 c->status.connecting = false;
217 getsockopt(c->socket, SOL_SOCKET, SO_ERROR, &result, &len);
220 finish_connecting(c);
222 ifdebug(CONNECTIONS) logger(LOG_DEBUG,
223 "Error while connecting to %s (%s): %s",
224 c->name, c->hostname, sockstrerror(result));
225 closesocket(c->socket);
226 do_outgoing_connection(c);
231 if (!receive_meta(c)) {
232 terminate_connection(c, c->status.active);
237 static void sigterm_handler(int signal, short events, void *data) {
238 logger(LOG_NOTICE, "Got %s signal", strsignal(signal));
239 event_loopexit(NULL);
242 static void sighup_handler(int signal, short events, void *data) {
243 logger(LOG_NOTICE, "Got %s signal", strsignal(signal));
245 reload_configuration();
248 static void sigalrm_handler(int signal, short events, void *data) {
249 logger(LOG_NOTICE, "Got %s signal", strsignal(signal));
253 int reload_configuration(void) {
255 splay_node_t *node, *next;
258 static time_t last_config_check = 0;
260 /* Reread our own configuration file */
262 exit_configuration(&config_tree);
263 init_configuration(&config_tree);
265 if(!read_server_config()) {
266 logger(LOG_ERR, "Unable to reread configuration file, exitting.");
267 event_loopexit(NULL);
271 /* Close connections to hosts that have a changed or deleted host config file */
273 for(node = connection_tree->head; node; node = next) {
278 free(c->outgoing->name);
280 freeaddrinfo(c->outgoing->ai);
285 xasprintf(&fname, "%s/hosts/%s", confbase, c->name);
286 if(stat(fname, &s) || s.st_mtime > last_config_check)
287 terminate_connection(c, c->status.active);
291 last_config_check = time(NULL);
293 /* If StrictSubnet is set, expire deleted Subnets and read new ones in */
299 for(node = subnet_tree->head; node; node = node->next) {
306 for(node = subnet_tree->head; node; node = next) {
309 if(subnet->expires == 1) {
310 send_del_subnet(broadcast, subnet);
311 if(subnet->owner->status.reachable)
312 subnet_update(subnet->owner, subnet, false);
313 subnet_del(subnet->owner, subnet);
314 } else if(subnet->expires == -1) {
317 send_add_subnet(broadcast, subnet);
318 if(subnet->owner->status.reachable)
319 subnet_update(subnet->owner, subnet, true);
324 /* Try to make outgoing connections */
326 try_outgoing_connections();
335 for(node = connection_tree->head; node; node = node->next) {
338 if(c->outgoing && !c->node) {
339 if(timeout_initialized(&c->outgoing->ev))
340 event_del(&c->outgoing->ev);
341 if(c->status.connecting)
343 c->outgoing->timeout = 0;
344 do_outgoing_connection(c);
350 this is where it all happens...
352 int main_loop(void) {
353 struct event timeout_event;
355 timeout_set(&timeout_event, timeout_handler, &timeout_event);
356 event_add(&timeout_event, &(struct timeval){pingtimeout, 0});
359 struct event sighup_event;
360 struct event sigterm_event;
361 struct event sigquit_event;
362 struct event sigalrm_event;
364 signal_set(&sighup_event, SIGHUP, sighup_handler, NULL);
365 signal_add(&sighup_event, NULL);
366 signal_set(&sigterm_event, SIGTERM, sigterm_handler, NULL);
367 signal_add(&sigterm_event, NULL);
368 signal_set(&sigquit_event, SIGQUIT, sigterm_handler, NULL);
369 signal_add(&sigquit_event, NULL);
370 signal_set(&sigalrm_event, SIGALRM, sigalrm_handler, NULL);
371 signal_add(&sigalrm_event, NULL);
374 if(event_loop(0) < 0) {
375 logger(LOG_ERR, "Error while waiting for input: %s", strerror(errno));
380 signal_del(&sighup_event);
381 signal_del(&sigterm_event);
382 signal_del(&sigquit_event);
383 signal_del(&sigalrm_event);
386 event_del(&timeout_event);