2 net.c -- most of the network code
3 Copyright (C) 1998-2005 Ivo Timmermans <ivo@tinc-vpn.org>,
4 2000-2005 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>
30 #include "connection.h"
44 bool do_purge = false;
45 volatile bool running = false;
49 /* Purge edges and subnets of unreachable nodes. Use carefully. */
51 static void purge(void)
53 avl_node_t *nnode, *nnext, *enode, *enext, *snode, *snext;
60 ifdebug(PROTOCOL) logger(LOG_DEBUG, _("Purging unreachable nodes"));
62 /* Remove all edges and subnets owned by unreachable nodes. */
64 for(nnode = node_tree->head; nnode; nnode = nnext) {
68 if(!n->status.reachable) {
69 ifdebug(SCARY_THINGS) logger(LOG_DEBUG, _("Purging node %s (%s)"), n->name,
72 for(snode = n->subnet_tree->head; snode; snode = snext) {
76 send_del_subnet(broadcast, s);
80 for(enode = n->edge_tree->head; enode; enode = enext) {
84 send_del_edge(broadcast, e);
90 /* Check if anyone else claims to have an edge to an unreachable node. If not, delete node. */
92 for(nnode = node_tree->head; nnode; nnode = nnext) {
96 if(!n->status.reachable) {
97 for(enode = edge_weight_tree->head; enode; enode = enext) {
112 put all file descriptors in an fd_set array
113 While we're at it, purge stuff that needs to be removed.
115 static int build_fdset(fd_set * fs)
117 avl_node_t *node, *next;
125 for(node = connection_tree->head; node; node = next) {
129 if(c->status.remove) {
131 if(!connection_tree->head)
134 FD_SET(c->socket, fs);
140 for(i = 0; i < listen_sockets; i++) {
141 FD_SET(listen_socket[i].tcp, fs);
142 if(listen_socket[i].tcp > max)
143 max = listen_socket[i].tcp;
144 FD_SET(listen_socket[i].udp, fs);
145 if(listen_socket[i].udp > max)
146 max = listen_socket[i].udp;
149 FD_SET(device_fd, fs);
157 Terminate a connection:
159 - Remove associated edge and tell other connections about it if report = true
160 - Check if we need to retry making an outgoing connection
161 - Deactivate the host
163 void terminate_connection(connection_t *c, bool report)
170 ifdebug(CONNECTIONS) logger(LOG_NOTICE, _("Closing connection with %s (%s)"),
171 c->name, c->hostname);
173 c->status.remove = true;
174 c->status.active = false;
177 c->node->connection = NULL;
180 closesocket(c->socket);
183 if(report && !tunnelserver)
184 send_del_edge(broadcast, c->edge);
188 /* Run MST and SSSP algorithms */
192 /* If the node is not reachable anymore but we remember it had an edge to us, clean it up */
194 if(report && !c->node->status.reachable) {
196 e = lookup_edge(c->node, myself);
199 send_del_edge(broadcast, e);
205 /* Check if this was our outgoing connection */
208 retry_outgoing(c->outgoing);
214 Check if the other end is active.
215 If we have sent packets, but didn't receive any,
216 then possibly the other end is dead. We send a
217 PING request over the meta connection. If the other
218 end does not reply in time, we consider them dead
219 and close the connection.
221 static void check_dead_connections(void)
223 avl_node_t *node, *next;
228 for(node = connection_tree->head; node; node = next) {
232 if(c->last_ping_time + pingtimeout < now) {
233 if(c->status.active) {
234 if(c->status.pinged) {
235 ifdebug(CONNECTIONS) logger(LOG_INFO, _("%s (%s) didn't respond to PING"),
236 c->name, c->hostname);
237 c->status.timeout = true;
238 terminate_connection(c, true);
243 if(c->status.remove) {
244 logger(LOG_WARNING, _("Old connection_t for %s (%s) status %04x still lingering, deleting..."),
245 c->name, c->hostname, *(uint32_t *)&c->status);
249 ifdebug(CONNECTIONS) logger(LOG_WARNING, _("Timeout from %s (%s) during authentication"),
250 c->name, c->hostname);
251 if(c->status.connecting) {
252 c->status.connecting = false;
253 closesocket(c->socket);
254 do_outgoing_connection(c);
256 terminate_connection(c, false);
264 check all connections to see if anything
265 happened on their sockets
267 static void check_network_activity(fd_set * f)
272 int len = sizeof(result);
277 if(FD_ISSET(device_fd, f)) {
278 if(read_packet(&packet))
279 route(myself, &packet);
282 for(node = connection_tree->head; node; node = node->next) {
288 if(FD_ISSET(c->socket, f)) {
289 if(c->status.connecting) {
290 c->status.connecting = false;
291 getsockopt(c->socket, SOL_SOCKET, SO_ERROR, &result, &len);
294 finish_connecting(c);
296 ifdebug(CONNECTIONS) logger(LOG_DEBUG,
297 _("Error while connecting to %s (%s): %s"),
298 c->name, c->hostname, strerror(result));
299 closesocket(c->socket);
300 do_outgoing_connection(c);
305 if(!receive_meta(c)) {
306 terminate_connection(c, c->status.active);
312 for(i = 0; i < listen_sockets; i++) {
313 if(FD_ISSET(listen_socket[i].udp, f))
314 handle_incoming_vpn_data(listen_socket[i].udp);
316 if(FD_ISSET(listen_socket[i].tcp, f))
317 handle_new_meta_connection(listen_socket[i].tcp);
322 this is where it all happens...
329 time_t last_ping_check, last_config_check;
334 last_ping_check = now;
335 last_config_check = now;
343 // tv.tv_sec = 1 + (rand() & 7); /* Approx. 5 seconds, randomized to prevent global synchronisation effects */
347 maxfd = build_fdset(&fset);
349 r = select(maxfd + 1, &fset, NULL, NULL, &tv);
352 if(errno != EINTR && errno != EAGAIN) {
353 logger(LOG_ERR, _("Error while waiting for input: %s"),
363 check_network_activity(&fset);
370 /* Let's check if everybody is still alive */
372 if(last_ping_check + pingtimeout < now) {
373 check_dead_connections();
374 last_ping_check = now;
376 if(routing_mode == RMODE_SWITCH)
381 /* Should we regenerate our key? */
383 if(keyexpires < now) {
384 ifdebug(STATUS) logger(LOG_INFO, _("Regenerating symmetric key"));
386 RAND_pseudo_bytes(myself->key, myself->keylength);
388 EVP_DecryptInit_ex(&packet_ctx, myself->cipher, NULL, myself->key, myself->key + myself->cipher->key_len);
389 send_key_changed(broadcast, myself);
390 keyexpires = now + keylifetime;
395 while((event = get_expired_event())) {
396 event->handler(event->data);
401 logger(LOG_INFO, _("Flushing event queue"));
403 while(event_tree->head) {
404 event = event_tree->head->data;
405 event->handler(event->data);
419 /* Reread our own configuration file */
421 exit_configuration(&config_tree);
422 init_configuration(&config_tree);
424 if(!read_server_config()) {
425 logger(LOG_ERR, _("Unable to reread configuration file, exitting."));
429 /* Close connections to hosts that have a changed or deleted host config file */
431 for(node = connection_tree->head; node; node = node->next) {
435 free(c->outgoing->name);
436 freeaddrinfo(c->outgoing->ai);
441 asprintf(&fname, "%s/hosts/%s", confbase, c->name);
442 if(stat(fname, &s) || s.st_mtime > last_config_check)
443 terminate_connection(c, c->status.active);
447 last_config_check = now;
449 /* Try to make outgoing connections */
451 try_outgoing_connections();