2 net.c -- most of the network code
3 Copyright (C) 1998-2005 Ivo Timmermans,
4 2000-2010 Guus Sliepen <guus@tinc-vpn.org>
5 2006 Scott Lamb <slamb@slamb.org>
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License along
18 with this program; if not, write to the Free Software Foundation, Inc.,
19 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
25 #include "splay_tree.h"
27 #include "connection.h"
39 int contradicting_add_edge = 0;
40 int contradicting_del_edge = 0;
42 /* Purge edges and subnets of unreachable nodes. Use carefully. */
45 splay_node_t *nnode, *nnext, *enode, *enext, *snode, *snext;
50 ifdebug(PROTOCOL) logger(LOG_DEBUG, "Purging unreachable nodes");
52 /* Remove all edges and subnets owned by unreachable nodes. */
54 for(nnode = node_tree->head; nnode; nnode = nnext) {
58 if(!n->status.reachable) {
59 ifdebug(SCARY_THINGS) logger(LOG_DEBUG, "Purging node %s (%s)", n->name,
62 for(snode = n->subnet_tree->head; snode; snode = snext) {
65 send_del_subnet(broadcast, s);
70 for(enode = n->edge_tree->head; enode; enode = enext) {
74 send_del_edge(broadcast, e);
80 /* Check if anyone else claims to have an edge to an unreachable node. If not, delete node. */
82 for(nnode = node_tree->head; nnode; nnode = nnext) {
86 if(!n->status.reachable) {
87 for(enode = edge_weight_tree->head; enode; enode = enext) {
95 if(!enode && (!strictsubnets || !n->subnet_tree->head))
96 /* in strictsubnets mode do not delete nodes with subnets */
103 Terminate a connection:
105 - Remove associated edge and tell other connections about it if report = true
106 - Check if we need to retry making an outgoing connection
107 - Deactivate the host
109 void terminate_connection(connection_t *c, bool report) {
110 ifdebug(CONNECTIONS) logger(LOG_NOTICE, "Closing connection with %s (%s)",
111 c->name, c->hostname);
113 c->status.active = false;
116 c->node->connection = NULL;
119 closesocket(c->socket);
122 if(report && !tunnelserver)
123 send_del_edge(broadcast, c->edge);
127 /* Run MST and SSSP algorithms */
131 /* If the node is not reachable anymore but we remember it had an edge to us, clean it up */
133 if(report && !c->node->status.reachable) {
135 e = lookup_edge(c->node, myself);
138 send_del_edge(broadcast, e);
144 /* Check if this was our outgoing connection */
147 retry_outgoing(c->outgoing);
153 Check if the other end is active.
154 If we have sent packets, but didn't receive any,
155 then possibly the other end is dead. We send a
156 PING request over the meta connection. If the other
157 end does not reply in time, we consider them dead
158 and close the connection.
160 static void timeout_handler(int fd, short events, void *event) {
161 splay_node_t *node, *next;
163 time_t now = time(NULL);
165 for(node = connection_tree->head; node; node = next) {
169 if(c->last_ping_time + pingtimeout < now) {
170 if(c->status.active) {
171 if(c->status.pinged) {
172 ifdebug(CONNECTIONS) logger(LOG_INFO, "%s (%s) didn't respond to PING in %ld seconds",
173 c->name, c->hostname, now - c->last_ping_time);
174 terminate_connection(c, true);
176 } else if(c->last_ping_time + pinginterval < now) {
180 if(c->status.connecting) {
182 logger(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 ifdebug(CONNECTIONS) logger(LOG_WARNING, "Timeout from %s (%s) during authentication", c->name, c->hostname);
188 terminate_connection(c, false);
195 if(contradicting_del_edge && contradicting_add_edge) {
196 logger(LOG_WARNING, "Possible node with same Name as us!");
198 if(rand() % 3 == 0) {
199 logger(LOG_ERR, "Shutting down, check configuration of all nodes for duplicate Names!");
200 event_loopexit(NULL);
204 contradicting_add_edge = 0;
205 contradicting_del_edge = 0;
208 event_add(event, &(struct timeval){pingtimeout, 0});
211 void handle_meta_connection_data(void *data) {
212 connection_t *c = data;
214 socklen_t len = sizeof result;
216 if(c->status.connecting) {
217 c->status.connecting = false;
219 getsockopt(c->socket, SOL_SOCKET, SO_ERROR, &result, &len);
222 finish_connecting(c);
224 ifdebug(CONNECTIONS) logger(LOG_DEBUG,
225 "Error while connecting to %s (%s): %s",
226 c->name, c->hostname, sockstrerror(result));
227 closesocket(c->socket);
228 do_outgoing_connection(c);
234 if (!receive_meta(c)) {
235 terminate_connection(c, c->status.active);
241 static void sigterm_handler(int signal, short events, void *data) {
242 logger(LOG_NOTICE, "Got %s signal", strsignal(signal));
243 event_loopexit(NULL);
246 static void sighup_handler(int signal, short events, void *data) {
247 logger(LOG_NOTICE, "Got %s signal", strsignal(signal));
248 reload_configuration();
251 int reload_configuration(void) {
253 splay_node_t *node, *next;
256 static time_t last_config_check = 0;
258 /* Reread our own configuration file */
260 exit_configuration(&config_tree);
261 init_configuration(&config_tree);
263 if(!read_server_config()) {
264 logger(LOG_ERR, "Unable to reread configuration file, exitting.");
265 event_loopexit(NULL);
269 /* Close connections to hosts that have a changed or deleted host config file */
271 for(node = connection_tree->head; node; node = next) {
276 free(c->outgoing->name);
278 freeaddrinfo(c->outgoing->ai);
283 xasprintf(&fname, "%s/hosts/%s", confbase, c->name);
284 if(stat(fname, &s) || s.st_mtime > last_config_check)
285 terminate_connection(c, c->status.active);
289 last_config_check = time(NULL);
291 /* If StrictSubnet is set, expire deleted Subnets and read new ones in */
297 for(node = subnet_tree->head; node; node = node->next) {
304 for(node = subnet_tree->head; node; node = next) {
307 if(subnet->expires == 1) {
308 send_del_subnet(broadcast, subnet);
309 if(subnet->owner->status.reachable)
310 subnet_update(subnet->owner, subnet, false);
311 subnet_del(subnet->owner, subnet);
312 } else if(subnet->expires == -1) {
315 send_add_subnet(broadcast, subnet);
316 if(subnet->owner->status.reachable)
317 subnet_update(subnet->owner, subnet, true);
322 /* Try to make outgoing connections */
324 try_outgoing_connections();
333 for(node = connection_tree->head; node; node = node->next) {
336 if(c->outgoing && !c->node) {
337 if(timeout_initialized(&c->outgoing->ev))
338 event_del(&c->outgoing->ev);
339 if(c->status.connecting)
341 c->outgoing->timeout = 0;
342 do_outgoing_connection(c);
348 this is where it all happens...
350 int main_loop(void) {
351 struct event timeout_event;
352 struct event sighup_event;
353 struct event sigterm_event;
354 struct event sigquit_event;
356 timeout_set(&timeout_event, timeout_handler, &timeout_event);
357 event_add(&timeout_event, &(struct timeval){pingtimeout, 0});
360 signal_set(&sighup_event, SIGHUP, sighup_handler, NULL);
361 signal_add(&sighup_event, NULL);
364 signal_set(&sigterm_event, SIGTERM, sigterm_handler, NULL);
365 signal_add(&sigterm_event, NULL);
368 signal_set(&sigquit_event, SIGQUIT, sigterm_handler, NULL);
369 signal_add(&sigquit_event, NULL);
372 if(event_loop(0) < 0) {
373 logger(LOG_ERR, "Error while waiting for input: %s", strerror(errno));
377 signal_del(&sighup_event);
378 signal_del(&sigterm_event);
379 signal_del(&sigquit_event);
380 event_del(&timeout_event);