2 net.c -- most of the network code
3 Copyright (C) 1998-2005 Ivo Timmermans,
4 2000-2009 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.
24 #include <openssl/rand.h>
27 #include "splay_tree.h"
29 #include "connection.h"
41 /* Purge edges and subnets of unreachable nodes. Use carefully. */
44 splay_node_t *nnode, *nnext, *enode, *enext, *snode, *snext;
49 ifdebug(PROTOCOL) logger(LOG_DEBUG, "Purging unreachable nodes");
51 /* Remove all edges and subnets owned by unreachable nodes. */
53 for(nnode = node_tree->head; nnode; nnode = nnext) {
57 if(!n->status.reachable) {
58 ifdebug(SCARY_THINGS) logger(LOG_DEBUG, "Purging node %s (%s)", n->name,
61 for(snode = n->subnet_tree->head; snode; snode = snext) {
65 send_del_subnet(broadcast, s);
69 for(enode = n->edge_tree->head; enode; enode = enext) {
73 send_del_edge(broadcast, e);
79 /* Check if anyone else claims to have an edge to an unreachable node. If not, delete node. */
81 for(nnode = node_tree->head; nnode; nnode = nnext) {
85 if(!n->status.reachable) {
86 for(enode = edge_weight_tree->head; enode; enode = enext) {
101 Terminate a connection:
103 - Remove associated edge and tell other connections about it if report = true
104 - Check if we need to retry making an outgoing connection
105 - Deactivate the host
107 void terminate_connection(connection_t *c, bool report) {
108 ifdebug(CONNECTIONS) logger(LOG_NOTICE, "Closing connection with %s (%s)",
109 c->name, c->hostname);
111 c->status.active = false;
114 c->node->connection = NULL;
117 closesocket(c->socket);
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 event_add(event, &(struct timeval){pingtimeout, 0});
196 void handle_meta_connection_data(int fd, short events, void *data) {
197 connection_t *c = data;
199 socklen_t len = sizeof result;
201 if(c->status.connecting) {
202 c->status.connecting = false;
204 getsockopt(c->socket, SOL_SOCKET, SO_ERROR, &result, &len);
207 finish_connecting(c);
209 ifdebug(CONNECTIONS) logger(LOG_DEBUG,
210 "Error while connecting to %s (%s): %s",
211 c->name, c->hostname, strerror(result));
212 closesocket(c->socket);
213 do_outgoing_connection(c);
218 if (!receive_meta(c)) {
219 terminate_connection(c, c->status.active);
224 static void sigterm_handler(int signal, short events, void *data) {
225 logger(LOG_NOTICE, "Got %s signal", strsignal(signal));
226 event_loopexit(NULL);
229 static void sighup_handler(int signal, short events, void *data) {
230 logger(LOG_NOTICE, "Got %s signal", strsignal(signal));
231 reload_configuration();
234 int reload_configuration(void) {
236 splay_node_t *node, *next;
239 static time_t last_config_check = 0;
241 /* Reread our own configuration file */
243 exit_configuration(&config_tree);
244 init_configuration(&config_tree);
246 if(!read_server_config()) {
247 logger(LOG_ERR, "Unable to reread configuration file, exitting.");
248 event_loopexit(NULL);
252 /* Close connections to hosts that have a changed or deleted host config file */
254 for(node = connection_tree->head; node; node = next) {
259 free(c->outgoing->name);
261 freeaddrinfo(c->outgoing->ai);
266 xasprintf(&fname, "%s/hosts/%s", confbase, c->name);
267 if(stat(fname, &s) || s.st_mtime > last_config_check)
268 terminate_connection(c, c->status.active);
272 last_config_check = time(NULL);
274 /* Try to make outgoing connections */
276 try_outgoing_connections();
285 for(node = connection_tree->head; node; node = node->next) {
288 if(c->outgoing && !c->node) {
289 if(timeout_initialized(&c->outgoing->ev))
290 event_del(&c->outgoing->ev);
291 if(c->status.connecting)
293 c->outgoing->timeout = 0;
294 do_outgoing_connection(c);
300 this is where it all happens...
302 int main_loop(void) {
303 struct event timeout_event;
304 struct event sighup_event;
305 struct event sigterm_event;
306 struct event sigquit_event;
308 timeout_set(&timeout_event, timeout_handler, &timeout_event);
309 event_add(&timeout_event, &(struct timeval){pingtimeout, 0});
310 signal_set(&sighup_event, SIGHUP, sighup_handler, NULL);
311 signal_add(&sighup_event, NULL);
312 signal_set(&sigterm_event, SIGTERM, sigterm_handler, NULL);
313 signal_add(&sigterm_event, NULL);
314 signal_set(&sigquit_event, SIGQUIT, sigterm_handler, NULL);
315 signal_add(&sigquit_event, NULL);
317 if(event_loop(0) < 0) {
318 logger(LOG_ERR, "Error while waiting for input: %s", strerror(errno));
322 signal_del(&sighup_event);
323 signal_del(&sigterm_event);
324 signal_del(&sigquit_event);
325 event_del(&timeout_event);