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>
28 #include "splay_tree.h"
30 #include "connection.h"
42 /* Purge edges and subnets of unreachable nodes. Use carefully. */
45 splay_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 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) {
113 ifdebug(CONNECTIONS) logger(LOG_NOTICE, _("Closing connection with %s (%s)"),
114 c->name, c->hostname);
116 c->status.active = false;
119 c->node->connection = NULL;
122 closesocket(c->socket);
125 if(report && !tunnelserver)
126 send_del_edge(broadcast, c->edge);
130 /* Run MST and SSSP algorithms */
134 /* If the node is not reachable anymore but we remember it had an edge to us, clean it up */
136 if(report && !c->node->status.reachable) {
138 e = lookup_edge(c->node, myself);
141 send_del_edge(broadcast, e);
147 /* Check if this was our outgoing connection */
150 retry_outgoing(c->outgoing);
156 Check if the other end is active.
157 If we have sent packets, but didn't receive any,
158 then possibly the other end is dead. We send a
159 PING request over the meta connection. If the other
160 end does not reply in time, we consider them dead
161 and close the connection.
163 static void timeout_handler(int fd, short events, void *event) {
164 splay_node_t *node, *next;
166 time_t now = time(NULL);
170 for(node = connection_tree->head; node; node = next) {
174 if(c->last_ping_time + pingtimeout < now) {
175 if(c->status.active) {
176 if(c->status.pinged) {
177 ifdebug(CONNECTIONS) logger(LOG_INFO, _("%s (%s) didn't respond to PING in %ld seconds"),
178 c->name, c->hostname, now - c->last_ping_time);
179 terminate_connection(c, true);
181 } else if(c->last_ping_time + pinginterval < now) {
185 if(c->status.connecting) {
187 logger(LOG_WARNING, _("Timeout while connecting to %s (%s)"), c->name, c->hostname);
188 c->status.connecting = false;
189 closesocket(c->socket);
190 do_outgoing_connection(c);
192 ifdebug(CONNECTIONS) logger(LOG_WARNING, _("Timeout from %s (%s) during authentication"), c->name, c->hostname);
193 terminate_connection(c, false);
200 event_add(event, &(struct timeval){pingtimeout, 0});
203 void handle_meta_connection_data(int fd, short events, void *data) {
204 connection_t *c = data;
206 socklen_t len = sizeof(result);
208 if(c->status.connecting) {
209 c->status.connecting = false;
211 getsockopt(c->socket, SOL_SOCKET, SO_ERROR, &result, &len);
214 finish_connecting(c);
216 ifdebug(CONNECTIONS) logger(LOG_DEBUG,
217 _("Error while connecting to %s (%s): %s"),
218 c->name, c->hostname, strerror(result));
219 closesocket(c->socket);
220 do_outgoing_connection(c);
225 if (!receive_meta(c)) {
226 terminate_connection(c, c->status.active);
231 static void sigterm_handler(int signal, short events, void *data) {
232 logger(LOG_NOTICE, _("Got %s signal"), strsignal(signal));
233 event_loopexit(NULL);
236 static void sigint_handler(int signal, short events, void *data) {
237 static int saved_debug_level = -1;
239 logger(LOG_NOTICE, _("Got %s signal"), strsignal(signal));
241 if(saved_debug_level != -1) {
242 logger(LOG_NOTICE, _("Reverting to old debug level (%d)"),
244 debug_level = saved_debug_level;
245 saved_debug_level = -1;
248 _("Temporarily setting debug level to 5. Kill me with SIGINT again to go back to level %d."),
250 saved_debug_level = debug_level;
255 static void sighup_handler(int signal, short events, void *data) {
257 splay_node_t *node, *next;
260 static time_t last_config_check = 0;
262 logger(LOG_NOTICE, _("Got %s signal"), strsignal(signal));
264 /* Reread our own configuration file */
266 exit_configuration(&config_tree);
267 init_configuration(&config_tree);
269 if(!read_server_config()) {
270 logger(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) {
282 free(c->outgoing->name);
284 freeaddrinfo(c->outgoing->ai);
289 asprintf(&fname, "%s/hosts/%s", confbase, c->name);
290 if(stat(fname, &s) || s.st_mtime > last_config_check)
291 terminate_connection(c, c->status.active);
295 last_config_check = time(NULL);
297 /* Try to make outgoing connections */
299 try_outgoing_connections();
302 static void sigalrm_handler(int signal, short events, void *data) {
303 logger(LOG_NOTICE, _("Got %s signal"), strsignal(signal));
308 for(node = connection_tree->head; node; node = node->next) {
311 if(c->outgoing && !c->node) {
312 if(timeout_initialized(&c->outgoing->ev))
313 event_del(&c->outgoing->ev);
314 if(c->status.connecting)
316 c->outgoing->timeout = 0;
317 do_outgoing_connection(c);
323 this is where it all happens...
325 int main_loop(void) {
326 struct event timeout_event;
327 struct event sighup_event;
328 struct event sigint_event;
329 struct event sigterm_event;
330 struct event sigquit_event;
331 struct event sigalrm_event;
335 timeout_set(&timeout_event, timeout_handler, &timeout_event);
336 event_add(&timeout_event, &(struct timeval){pingtimeout, 0});
337 signal_set(&sighup_event, SIGHUP, sighup_handler, NULL);
338 signal_add(&sighup_event, NULL);
339 signal_set(&sigint_event, SIGINT, sigint_handler, NULL);
340 signal_add(&sigint_event, NULL);
341 signal_set(&sigterm_event, SIGTERM, sigterm_handler, NULL);
342 signal_add(&sigterm_event, NULL);
343 signal_set(&sigquit_event, SIGQUIT, sigterm_handler, NULL);
344 signal_add(&sigquit_event, NULL);
345 signal_set(&sigalrm_event, SIGALRM, sigalrm_handler, NULL);
346 signal_add(&sigalrm_event, NULL);
348 if(event_loop(0) < 0) {
349 logger(LOG_ERR, _("Error while waiting for input: %s"), strerror(errno));
353 signal_del(&sighup_event);
354 signal_del(&sigint_event);
355 signal_del(&sigterm_event);
356 signal_del(&sigquit_event);
357 signal_del(&sigalrm_event);
358 event_del(&timeout_event);