2 net.c -- most of the network code
3 Copyright (C) 1998-2005 Ivo Timmermans,
4 2000-2013 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.
27 #include "connection.h"
43 int contradicting_add_edge
= 0;
44 int contradicting_del_edge
= 0;
45 static int sleeptime
= 10;
46 time_t last_config_check
= 0;
47 static timeout_t pingtimer
;
48 static timeout_t periodictimer
;
50 /* Purge edges and subnets of unreachable nodes. Use carefully. */
53 logger(DEBUG_PROTOCOL
, LOG_DEBUG
, "Purging unreachable nodes");
55 /* Remove all edges and subnets owned by unreachable nodes. */
57 for splay_each(node_t
, n
, node_tree
) {
58 if(!n
->status
.reachable
) {
59 logger(DEBUG_SCARY_THINGS
, LOG_DEBUG
, "Purging node %s (%s)", n
->name
, n
->hostname
);
61 for splay_each(subnet_t
, s
, n
->subnet_tree
) {
62 send_del_subnet(everyone
, s
);
67 for splay_each(edge_t
, e
, n
->edge_tree
) {
69 send_del_edge(everyone
, e
);
75 /* Check if anyone else claims to have an edge to an unreachable node. If not, delete node. */
77 for splay_each(node_t
, n
, node_tree
) {
78 if(!n
->status
.reachable
) {
79 for splay_each(edge_t
, e
, edge_weight_tree
)
83 if(!autoconnect
&& (!strictsubnets
|| !n
->subnet_tree
->head
))
84 /* in strictsubnets mode do not delete nodes with subnets */
91 Terminate a connection:
93 - Remove the edge representing this connection
95 - Check if we need to retry making an outgoing connection
97 void terminate_connection(connection_t
*c
, bool report
) {
98 logger(DEBUG_CONNECTIONS
, LOG_NOTICE
, "Closing connection with %s (%s)", c
->name
, c
->hostname
);
100 if(c
->node
&& c
->node
->connection
== c
)
101 c
->node
->connection
= NULL
;
104 if(report
&& !tunnelserver
)
105 send_del_edge(everyone
, c
->edge
);
110 /* Run MST and SSSP algorithms */
114 /* If the node is not reachable anymore but we remember it had an edge to us, clean it up */
116 if(report
&& !c
->node
->status
.reachable
) {
118 e
= lookup_edge(c
->node
, myself
);
121 send_del_edge(everyone
, e
);
127 outgoing_t
*outgoing
= c
->outgoing
;
130 /* Check if this was our outgoing connection */
133 do_outgoing_connection(outgoing
);
136 /* Clean up dead proxy processes */
138 while(waitpid(-1, NULL
, WNOHANG
) > 0);
143 Check if the other end is active.
144 If we have sent packets, but didn't receive any,
145 then possibly the other end is dead. We send a
146 PING request over the meta connection. If the other
147 end does not reply in time, we consider them dead
148 and close the connection.
150 static void timeout_handler(void *data
) {
151 for list_each(connection_t
, c
, connection_list
) {
152 if(c
->status
.control
)
155 if(c
->last_ping_time
+ pingtimeout
<= now
.tv_sec
) {
157 if(c
->status
.pinged
) {
158 logger(DEBUG_CONNECTIONS
, LOG_INFO
, "%s (%s) didn't respond to PING in %ld seconds", c
->name
, c
->hostname
, (long)now
.tv_sec
- c
->last_ping_time
);
159 } else if(c
->last_ping_time
+ pinginterval
<= now
.tv_sec
) {
166 if(c
->status
.connecting
)
167 logger(DEBUG_CONNECTIONS
, LOG_WARNING
, "Timeout while connecting to %s (%s)", c
->name
, c
->hostname
);
169 logger(DEBUG_CONNECTIONS
, LOG_WARNING
, "Timeout from %s (%s) during authentication", c
->name
, c
->hostname
);
171 terminate_connection(c
, c
->edge
);
175 timeout_set(data
, &(struct timeval
){pingtimeout
, rand() % 100000});
178 static void periodic_handler(void *data
) {
179 /* Check if there are too many contradicting ADD_EDGE and DEL_EDGE messages.
180 This usually only happens when another node has the same Name as this node.
181 If so, sleep for a short while to prevent a storm of contradicting messages.
184 if(contradicting_del_edge
> 100 && contradicting_add_edge
> 100) {
185 logger(DEBUG_ALWAYS
, LOG_WARNING
, "Possible node with same Name as us! Sleeping %d seconds.", sleeptime
);
186 usleep(sleeptime
* 1000000LL);
196 contradicting_add_edge
= 0;
197 contradicting_del_edge
= 0;
199 /* If AutoConnect is set, check if we need to make or break connections. */
201 if(autoconnect
&& node_tree
->count
> 1) {
202 /* Count number of active connections */
204 for list_each(connection_t
, c
, connection_list
) {
210 /* Not enough active connections, try to add one.
211 Choose a random node, if we don't have a connection to it,
212 and we are not already trying to make one, create an
213 outgoing connection to this node.
215 int r
= rand() % node_tree
->count
;
218 for splay_each(node_t
, n
, node_tree
) {
227 for list_each(outgoing_t
, outgoing
, outgoing_list
) {
228 if(!strcmp(outgoing
->name
, n
->name
)) {
235 logger(DEBUG_CONNECTIONS
, LOG_INFO
, "Autoconnecting to %s", n
->name
);
236 outgoing_t
*outgoing
= xzalloc(sizeof *outgoing
);
237 outgoing
->name
= xstrdup(n
->name
);
238 list_insert_tail(outgoing_list
, outgoing
);
239 setup_outgoing_connection(outgoing
);
244 /* Too many active connections, try to remove one.
245 Choose a random outgoing connection to a node
246 that has at least one other connection.
251 for list_each(connection_t
, c
, connection_list
) {
258 if(!c
->outgoing
|| !c
->node
|| c
->node
->edge_tree
->count
< 2)
261 logger(DEBUG_CONNECTIONS
, LOG_INFO
, "Autodisconnecting from %s", c
->name
);
262 list_delete(outgoing_list
, c
->outgoing
);
264 terminate_connection(c
, c
->edge
);
270 /* If we have enough active connections,
271 remove any pending outgoing connections.
273 for list_each(outgoing_t
, o
, outgoing_list
) {
275 for list_each(connection_t
, c
, connection_list
) {
276 if(c
->outgoing
== o
) {
282 logger(DEBUG_CONNECTIONS
, LOG_INFO
, "Cancelled outgoing connection to %s", o
->name
);
283 list_delete_node(outgoing_list
, node
);
289 timeout_set(data
, &(struct timeval
){5, rand() % 100000});
292 void handle_meta_connection_data(connection_t
*c
) {
293 if (!receive_meta(c
)) {
294 terminate_connection(c
, c
->edge
);
300 static void sigterm_handler(void *data
) {
301 logger(DEBUG_ALWAYS
, LOG_NOTICE
, "Got %s signal", strsignal(((signal_t
*)data
)->signum
));
305 static void sighup_handler(void *data
) {
306 logger(DEBUG_ALWAYS
, LOG_NOTICE
, "Got %s signal", strsignal(((signal_t
*)data
)->signum
));
308 if(reload_configuration())
312 static void sigalrm_handler(void *data
) {
313 logger(DEBUG_ALWAYS
, LOG_NOTICE
, "Got %s signal", strsignal(((signal_t
*)data
)->signum
));
314 #ifdef HAVE_DECL_RES_INIT
321 int reload_configuration(void) {
324 /* Reread our own configuration file */
326 exit_configuration(&config_tree
);
327 init_configuration(&config_tree
);
329 if(!read_server_config()) {
330 logger(DEBUG_ALWAYS
, LOG_ERR
, "Unable to reread configuration file.");
334 read_config_options(config_tree
, NULL
);
336 xasprintf(&fname
, "%s" SLASH
"hosts" SLASH
"%s", confbase
, myself
->name
);
337 read_config_file(config_tree
, fname
);
340 /* Parse some options that are allowed to be changed while tinc is running */
342 setup_myself_reloadable();
344 /* If StrictSubnet is set, expire deleted Subnets and read new ones in */
347 for splay_each(subnet_t
, subnet
, subnet_tree
)
353 for splay_each(subnet_t
, subnet
, subnet_tree
) {
356 if(subnet
->expires
== 1) {
357 send_del_subnet(everyone
, subnet
);
358 if(subnet
->owner
->status
.reachable
)
359 subnet_update(subnet
->owner
, subnet
, false);
360 subnet_del(subnet
->owner
, subnet
);
361 } else if(subnet
->expires
== -1) {
364 send_add_subnet(everyone
, subnet
);
365 if(subnet
->owner
->status
.reachable
)
366 subnet_update(subnet
->owner
, subnet
, true);
369 } else { /* Only read our own subnets back in */
370 for splay_each(subnet_t
, subnet
, myself
->subnet_tree
)
374 config_t
*cfg
= lookup_config(config_tree
, "Subnet");
377 subnet_t
*subnet
, *s2
;
379 if(!get_config_subnet(cfg
, &subnet
))
382 if((s2
= lookup_subnet(myself
, subnet
))) {
388 subnet_add(myself
, subnet
);
389 send_add_subnet(everyone
, subnet
);
390 subnet_update(myself
, subnet
, true);
393 cfg
= lookup_config_next(config_tree
, cfg
);
396 for splay_each(subnet_t
, subnet
, myself
->subnet_tree
) {
397 if(subnet
->expires
== 1) {
398 send_del_subnet(everyone
, subnet
);
399 subnet_update(myself
, subnet
, false);
400 subnet_del(myself
, subnet
);
405 /* Try to make outgoing connections */
407 try_outgoing_connections();
409 /* Close connections to hosts that have a changed or deleted host config file */
411 for list_each(connection_t
, c
, connection_list
) {
412 if(c
->status
.control
)
415 xasprintf(&fname
, "%s" SLASH
"hosts" SLASH
"%s", confbase
, c
->name
);
417 if(stat(fname
, &s
) || s
.st_mtime
> last_config_check
) {
418 logger(DEBUG_CONNECTIONS
, LOG_INFO
, "Host config file of %s has been changed", c
->name
);
419 terminate_connection(c
, c
->edge
);
424 last_config_check
= now
.tv_sec
;
430 /* Reset the reconnection timers for all outgoing connections */
431 for list_each(outgoing_t
, outgoing
, outgoing_list
) {
432 outgoing
->timeout
= 0;
434 timeout_set(&outgoing
->ev
, &(struct timeval
){0, 0});
437 /* Check for outgoing connections that are in progress, and reset their ping timers */
438 for list_each(connection_t
, c
, connection_list
) {
439 if(c
->outgoing
&& !c
->node
)
440 c
->last_ping_time
= 0;
443 /* Kick the ping timeout handler */
444 timeout_set(&pingtimer
, &(struct timeval
){0, 0});
448 this is where it all happens...
450 int main_loop(void) {
451 timeout_add(&pingtimer
, timeout_handler
, &pingtimer
, &(struct timeval
){pingtimeout
, rand() % 100000});
452 timeout_add(&periodictimer
, periodic_handler
, &periodictimer
, &(struct timeval
){pingtimeout
, rand() % 100000});
455 signal_t sighup
= {0};
456 signal_t sigterm
= {0};
457 signal_t sigquit
= {0};
458 signal_t sigint
= {0};
459 signal_t sigalrm
= {0};
461 signal_add(&sighup
, sighup_handler
, &sighup
, SIGHUP
);
462 signal_add(&sigterm
, sigterm_handler
, &sigterm
, SIGTERM
);
463 signal_add(&sigquit
, sigterm_handler
, &sigquit
, SIGQUIT
);
464 signal_add(&sigint
, sigterm_handler
, &sigint
, SIGINT
);
465 signal_add(&sigalrm
, sigalrm_handler
, &sigalrm
, SIGALRM
);
469 logger(DEBUG_ALWAYS
, LOG_ERR
, "Error while waiting for input: %s", sockstrerror(sockerrno
));
475 signal_del(&sigterm
);
476 signal_del(&sigquit
);
478 signal_del(&sigalrm
);
481 timeout_del(&periodictimer
);
482 timeout_del(&pingtimer
);