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;
42 static int sleeptime = 10;
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:
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 logger(DEBUG_CONNECTIONS, 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(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 /* 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->status.control)
170 if(c->last_ping_time + pingtimeout <= now) {
171 if(c->status.active) {
172 if(c->status.pinged) {
173 logger(DEBUG_CONNECTIONS, LOG_INFO, "%s (%s) didn't respond to PING in %ld seconds",
174 c->name, c->hostname, now - c->last_ping_time);
175 terminate_connection(c, true);
177 } else if(c->last_ping_time + pinginterval <= now) {
181 if(c->status.connecting) {
182 logger(DEBUG_CONNECTIONS, LOG_WARNING, "Timeout while connecting to %s (%s)", c->name, c->hostname);
183 c->status.connecting = false;
184 closesocket(c->socket);
185 do_outgoing_connection(c);
187 logger(DEBUG_CONNECTIONS, LOG_WARNING, "Timeout from %s (%s) during authentication", c->name, c->hostname);
188 terminate_connection(c, false);
195 if(contradicting_del_edge > 100 && contradicting_add_edge > 100) {
196 logger(DEBUG_ALWAYS, LOG_WARNING, "Possible node with same Name as us! Sleeping %d seconds.", sleeptime);
197 usleep(sleeptime * 1000000LL);
207 contradicting_add_edge = 0;
208 contradicting_del_edge = 0;
210 event_add(event, &(struct timeval){pingtimeout, 0});
213 void handle_meta_connection_data(int fd, short events, void *data) {
214 connection_t *c = data;
216 socklen_t len = sizeof result;
218 if(c->status.connecting) {
219 c->status.connecting = false;
221 getsockopt(c->socket, SOL_SOCKET, SO_ERROR, &result, &len);
224 finish_connecting(c);
226 logger(DEBUG_CONNECTIONS, LOG_DEBUG,
227 "Error while connecting to %s (%s): %s",
228 c->name, c->hostname, sockstrerror(result));
229 closesocket(c->socket);
230 do_outgoing_connection(c);
235 if (!receive_meta(c)) {
236 terminate_connection(c, c->status.active);
241 static void sigterm_handler(int signal, short events, void *data) {
242 logger(DEBUG_ALWAYS, LOG_NOTICE, "Got %s signal", strsignal(signal));
243 event_loopexit(NULL);
246 static void sighup_handler(int signal, short events, void *data) {
247 logger(DEBUG_ALWAYS, LOG_NOTICE, "Got %s signal", strsignal(signal));
249 reload_configuration();
252 static void sigalrm_handler(int signal, short events, void *data) {
253 logger(DEBUG_ALWAYS, LOG_NOTICE, "Got %s signal", strsignal(signal));
257 int reload_configuration(void) {
259 splay_node_t *node, *next;
262 static time_t last_config_check = 0;
264 /* Reread our own configuration file */
266 exit_configuration(&config_tree);
267 init_configuration(&config_tree);
269 if(!read_server_config()) {
270 logger(DEBUG_ALWAYS, LOG_ERR, "Unable to reread configuration file, exitting.");
271 event_loopexit(NULL);
275 /* Close connections to hosts that have a changed or deleted host config file */
277 for(node = connection_tree->head; node; node = next) {
281 if(c->status.control)
285 free(c->outgoing->name);
287 freeaddrinfo(c->outgoing->ai);
292 xasprintf(&fname, "%s/hosts/%s", confbase, c->name);
293 if(stat(fname, &s) || s.st_mtime > last_config_check)
294 terminate_connection(c, c->status.active);
298 last_config_check = time(NULL);
300 /* If StrictSubnet is set, expire deleted Subnets and read new ones in */
306 for(node = subnet_tree->head; node; node = node->next) {
313 for(node = subnet_tree->head; node; node = next) {
316 if(subnet->expires == 1) {
317 send_del_subnet(everyone, subnet);
318 if(subnet->owner->status.reachable)
319 subnet_update(subnet->owner, subnet, false);
320 subnet_del(subnet->owner, subnet);
321 } else if(subnet->expires == -1) {
324 send_add_subnet(everyone, subnet);
325 if(subnet->owner->status.reachable)
326 subnet_update(subnet->owner, subnet, true);
331 /* Try to make outgoing connections */
333 try_outgoing_connections();
342 for(node = connection_tree->head; node; node = node->next) {
345 if(c->outgoing && !c->node) {
346 if(timeout_initialized(&c->outgoing->ev))
347 event_del(&c->outgoing->ev);
348 if(c->status.connecting)
350 c->outgoing->timeout = 0;
351 do_outgoing_connection(c);
357 this is where it all happens...
359 int main_loop(void) {
360 struct event timeout_event;
362 timeout_set(&timeout_event, timeout_handler, &timeout_event);
363 event_add(&timeout_event, &(struct timeval){pingtimeout, 0});
366 struct event sighup_event;
367 struct event sigterm_event;
368 struct event sigquit_event;
369 struct event sigalrm_event;
371 signal_set(&sighup_event, SIGHUP, sighup_handler, NULL);
372 signal_add(&sighup_event, NULL);
373 signal_set(&sigterm_event, SIGTERM, sigterm_handler, NULL);
374 signal_add(&sigterm_event, NULL);
375 signal_set(&sigquit_event, SIGQUIT, sigterm_handler, NULL);
376 signal_add(&sigquit_event, NULL);
377 signal_set(&sigalrm_event, SIGALRM, sigalrm_handler, NULL);
378 signal_add(&sigalrm_event, NULL);
381 if(event_loop(0) < 0) {
382 logger(DEBUG_ALWAYS, LOG_ERR, "Error while waiting for input: %s", strerror(errno));
387 signal_del(&sighup_event);
388 signal_del(&sigterm_event);
389 signal_del(&sigquit_event);
390 signal_del(&sigalrm_event);
393 event_del(&timeout_event);