5f9e2173e749355b88ed7ec0d523cca1adcda08d
[oweals/tinc.git] / src / net_socket.c
1 /*
2     net_socket.c -- Handle various kinds of sockets.
3     Copyright (C) 1998-2003 Ivo Timmermans <ivo@o2w.nl>,
4                   2000-2003 Guus Sliepen <guus@sliepen.eu.org>
5
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.
10
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.
15
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.
19
20     $Id: net_socket.c,v 1.1.2.32 2003/07/28 22:06:09 guus Exp $
21 */
22
23 #include "system.h"
24
25 #include "avl_tree.h"
26 #include "conf.h"
27 #include "connection.h"
28 #include "event.h"
29 #include "logger.h"
30 #include "meta.h"
31 #include "net.h"
32 #include "netutl.h"
33 #include "protocol.h"
34 #include "utils.h"
35 #include "xalloc.h"
36
37 #ifdef WSAEINPROGRESS
38 #define EINPROGRESS WSAEINPROGRESS
39 #endif
40
41 int addressfamily = AF_UNSPEC;
42 int maxtimeout = 900;
43 int seconds_till_retry = 5;
44
45 listen_socket_t listen_socket[MAXSOCKETS];
46 int listen_sockets;
47
48 /* Setup sockets */
49
50 int setup_listen_socket(const sockaddr_t *sa)
51 {
52         int nfd, flags;
53         char *addrstr;
54         int option;
55         char *iface;
56 #ifdef SO_BINDTODEVICE
57         struct ifreq ifr;
58 #endif
59
60         cp();
61
62         nfd = socket(sa->sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
63
64         if(nfd < 0) {
65                 logger(LOG_ERR, _("Creating metasocket failed: %s"), strerror(errno));
66                 return -1;
67         }
68
69 #ifdef O_NONBLOCK
70         flags = fcntl(nfd, F_GETFL);
71
72         if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0) {
73                 close(nfd);
74                 logger(LOG_ERR, _("System call `%s' failed: %s"), "fcntl",
75                            strerror(errno));
76                 return -1;
77         }
78 #endif
79
80         /* Optimize TCP settings */
81
82         option = 1;
83         setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &option, sizeof(option));
84
85 #if defined(SOL_TCP) && defined(TCP_NODELAY)
86         setsockopt(nfd, SOL_TCP, TCP_NODELAY, &option, sizeof(option));
87 #endif
88
89 #if defined(SOL_IP) && defined(IP_TOS) && defined(IPTOS_LOWDELAY)
90         option = IPTOS_LOWDELAY;
91         setsockopt(nfd, SOL_IP, IP_TOS, &option, sizeof(option));
92 #endif
93
94         if(get_config_string
95            (lookup_config(config_tree, "BindToInterface"), &iface)) {
96 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
97                 memset(&ifr, 0, sizeof(ifr));
98                 strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
99
100                 if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr))) {
101                         close(nfd);
102                         logger(LOG_ERR, _("Can't bind to interface %s: %s"), iface,
103                                    strerror(errno));
104                         return -1;
105                 }
106 #else
107                 logger(LOG_WARNING, _("BindToInterface not supported on this platform"));
108 #endif
109         }
110
111         if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
112                 close(nfd);
113                 addrstr = sockaddr2hostname(sa);
114                 logger(LOG_ERR, _("Can't bind to %s/tcp: %s"), addrstr,
115                            strerror(errno));
116                 free(addrstr);
117                 return -1;
118         }
119
120         if(listen(nfd, 3)) {
121                 close(nfd);
122                 logger(LOG_ERR, _("System call `%s' failed: %s"), "listen",
123                            strerror(errno));
124                 return -1;
125         }
126
127         return nfd;
128 }
129
130 int setup_vpn_in_socket(const sockaddr_t *sa)
131 {
132         int nfd, flags;
133         char *addrstr;
134         int option;
135 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
136         char *iface;
137         struct ifreq ifr;
138 #endif
139
140         cp();
141
142         nfd = socket(sa->sa.sa_family, SOCK_DGRAM, IPPROTO_UDP);
143
144         if(nfd < 0) {
145                 logger(LOG_ERR, _("Creating UDP socket failed: %s"), strerror(errno));
146                 return -1;
147         }
148
149 #ifdef O_NONBLOCK
150         flags = fcntl(nfd, F_GETFL);
151         if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0) {
152                 close(nfd);
153                 logger(LOG_ERR, _("System call `%s' failed: %s"), "fcntl",
154                            strerror(errno));
155                 return -1;
156         }
157 #endif
158
159         option = 1;
160         setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &option, sizeof(option));
161
162 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
163         if(get_config_string
164            (lookup_config(config_tree, "BindToInterface"), &iface)) {
165                 memset(&ifr, 0, sizeof(ifr));
166                 strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
167
168                 if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr))) {
169                         close(nfd);
170                         logger(LOG_ERR, _("Can't bind to interface %s: %s"), iface,
171                                    strerror(errno));
172                         return -1;
173                 }
174         }
175 #endif
176
177         if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
178                 close(nfd);
179                 addrstr = sockaddr2hostname(sa);
180                 logger(LOG_ERR, _("Can't bind to %s/udp: %s"), addrstr,
181                            strerror(errno));
182                 free(addrstr);
183                 return -1;
184         }
185
186         return nfd;
187 }
188
189 void retry_outgoing(outgoing_t *outgoing)
190 {
191         event_t *event;
192
193         cp();
194
195         outgoing->timeout += 5;
196
197         if(outgoing->timeout > maxtimeout)
198                 outgoing->timeout = maxtimeout;
199
200         event = new_event();
201         event->handler = (event_handler_t) setup_outgoing_connection;
202         event->time = now + outgoing->timeout;
203         event->data = outgoing;
204         event_add(event);
205
206         ifdebug(CONNECTIONS) logger(LOG_NOTICE,
207                            _("Trying to re-establish outgoing connection in %d seconds"),
208                            outgoing->timeout);
209 }
210
211 void finish_connecting(connection_t *c)
212 {
213         cp();
214
215         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Connected to %s (%s)"), c->name, c->hostname);
216
217         c->last_ping_time = now;
218
219         send_id(c);
220 }
221
222 void do_outgoing_connection(connection_t *c)
223 {
224         char *address, *port;
225         int option, result, flags;
226
227         cp();
228
229 begin:
230         if(!c->outgoing->ai) {
231                 if(!c->outgoing->cfg) {
232                         ifdebug(CONNECTIONS) logger(LOG_ERR, _("Could not set up a meta connection to %s"),
233                                            c->name);
234                         c->status.remove = true;
235                         retry_outgoing(c->outgoing);
236                         return;
237                 }
238
239                 get_config_string(c->outgoing->cfg, &address);
240
241                 if(!get_config_string(lookup_config(c->config_tree, "Port"), &port))
242                         asprintf(&port, "655");
243
244                 c->outgoing->ai = str2addrinfo(address, port, SOCK_STREAM);
245                 free(address);
246                 free(port);
247
248                 c->outgoing->aip = c->outgoing->ai;
249                 c->outgoing->cfg = lookup_config_next(c->config_tree, c->outgoing->cfg);
250         }
251
252         if(!c->outgoing->aip) {
253                 freeaddrinfo(c->outgoing->ai);
254                 c->outgoing->ai = NULL;
255                 goto begin;
256         }
257
258         memcpy(&c->address, c->outgoing->aip->ai_addr,
259                    c->outgoing->aip->ai_addrlen);
260         c->outgoing->aip = c->outgoing->aip->ai_next;
261
262         if(c->hostname)
263                 free(c->hostname);
264
265         c->hostname = sockaddr2hostname(&c->address);
266
267         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Trying to connect to %s (%s)"), c->name,
268                            c->hostname);
269
270         c->socket = socket(c->address.sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
271
272         if(c->socket == -1) {
273                 ifdebug(CONNECTIONS) logger(LOG_ERR, _("Creating socket for %s failed: %s"), c->hostname,
274                                    strerror(errno));
275
276                 goto begin;
277         }
278
279         /* Optimize TCP settings */
280
281 #if defined(SOL_TCP) && defined(TCP_NODELAY)
282         option = 1;
283         setsockopt(c->socket, SOL_TCP, TCP_NODELAY, &option, sizeof(option));
284 #endif
285
286 #if defined(SOL_IP) && defined(IP_TOS)
287         option = IPTOS_LOWDELAY;
288         setsockopt(c->socket, SOL_IP, IP_TOS, &option, sizeof(option));
289 #endif
290
291         /* Non-blocking */
292
293 #ifdef O_NONBLOCK
294         flags = fcntl(c->socket, F_GETFL);
295
296         if(fcntl(c->socket, F_SETFL, flags | O_NONBLOCK) < 0) {
297                 logger(LOG_ERR, _("fcntl for %s: %s"), c->hostname, strerror(errno));
298         }
299 #endif
300
301         /* Connect */
302
303         result = connect(c->socket, &c->address.sa, SALEN(c->address.sa));
304
305         if(result == -1) {
306                 if(errno == EINPROGRESS) {
307                         c->status.connecting = true;
308                         return;
309                 }
310
311                 close(c->socket);
312
313                 ifdebug(CONNECTIONS) logger(LOG_ERR, _("%s: %s"), c->hostname, strerror(errno));
314
315                 goto begin;
316         }
317
318         finish_connecting(c);
319
320         return;
321 }
322
323 void setup_outgoing_connection(outgoing_t *outgoing)
324 {
325         connection_t *c;
326         node_t *n;
327
328         cp();
329
330         n = lookup_node(outgoing->name);
331
332         if(n)
333                 if(n->connection) {
334                         ifdebug(CONNECTIONS) logger(LOG_INFO, _("Already connected to %s"), outgoing->name);
335
336                         n->connection->outgoing = outgoing;
337                         return;
338                 }
339
340         c = new_connection();
341         c->name = xstrdup(outgoing->name);
342         c->outcipher = myself->connection->outcipher;
343         c->outdigest = myself->connection->outdigest;
344         c->outmaclength = myself->connection->outmaclength;
345         c->outcompression = myself->connection->outcompression;
346
347         init_configuration(&c->config_tree);
348         read_connection_config(c);
349
350         outgoing->cfg = lookup_config(c->config_tree, "Address");
351
352         if(!outgoing->cfg) {
353                 logger(LOG_ERR, _("No address specified for %s"), c->name);
354                 free_connection(c);
355                 free(outgoing->name);
356                 free(outgoing);
357                 return;
358         }
359
360         c->outgoing = outgoing;
361         c->last_ping_time = now;
362
363         connection_add(c);
364
365         do_outgoing_connection(c);
366 }
367
368 /*
369   accept a new tcp connect and create a
370   new connection
371 */
372 bool handle_new_meta_connection(int sock)
373 {
374         connection_t *c;
375         sockaddr_t sa;
376         int fd, len = sizeof(sa);
377
378         cp();
379
380         fd = accept(sock, &sa.sa, &len);
381
382         if(fd < 0) {
383                 logger(LOG_ERR, _("Accepting a new connection failed: %s"),
384                            strerror(errno));
385                 return false;
386         }
387
388         sockaddrunmap(&sa);
389
390         c = new_connection();
391         c->outcipher = myself->connection->outcipher;
392         c->outdigest = myself->connection->outdigest;
393         c->outmaclength = myself->connection->outmaclength;
394         c->outcompression = myself->connection->outcompression;
395
396         c->address = sa;
397         c->hostname = sockaddr2hostname(&sa);
398         c->socket = fd;
399         c->last_ping_time = now;
400
401         ifdebug(CONNECTIONS) logger(LOG_NOTICE, _("Connection from %s"), c->hostname);
402
403         connection_add(c);
404
405         c->allow_request = ID;
406         send_id(c);
407
408         return true;
409 }
410
411 void try_outgoing_connections(void)
412 {
413         static config_t *cfg = NULL;
414         char *name;
415         outgoing_t *outgoing;
416
417         cp();
418
419         for(cfg = lookup_config(config_tree, "ConnectTo"); cfg;
420                 cfg = lookup_config_next(config_tree, cfg)) {
421                 get_config_string(cfg, &name);
422
423                 if(!check_id(name)) {
424                         logger(LOG_ERR,
425                                    _("Invalid name for outgoing connection in %s line %d"),
426                                    cfg->file, cfg->line);
427                         free(name);
428                         continue;
429                 }
430
431                 outgoing = xmalloc_and_zero(sizeof(*outgoing));
432                 outgoing->name = name;
433                 setup_outgoing_connection(outgoing);
434         }
435 }