]> git.meshlink.io Git - meshlink/blob - src/net_socket.c
Merge branch 'master' of git://tinc-vpn.org/tinc into 1.1
[meshlink] / src / net_socket.c
1 /*
2     net_socket.c -- Handle various kinds of sockets.
3     Copyright (C) 1998-2005 Ivo Timmermans,
4                   2000-2012 Guus Sliepen <guus@tinc-vpn.org>
5                   2006      Scott Lamb <slamb@slamb.org>
6                   2009      Florian Forster <octo@verplant.org>
7
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.
12
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.
17
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.
21 */
22
23 #include "system.h"
24
25 #include "splay_tree.h"
26 #include "conf.h"
27 #include "connection.h"
28 #include "logger.h"
29 #include "meta.h"
30 #include "net.h"
31 #include "netutl.h"
32 #include "protocol.h"
33 #include "utils.h"
34 #include "xalloc.h"
35
36 /* Needed on Mac OS/X */
37 #ifndef SOL_TCP
38 #define SOL_TCP IPPROTO_TCP
39 #endif
40
41 int addressfamily = AF_UNSPEC;
42 int maxtimeout = 900;
43 int seconds_till_retry = 5;
44 int udp_rcvbuf = 0;
45 int udp_sndbuf = 0;
46
47 listen_socket_t listen_socket[MAXSOCKETS];
48 int listen_sockets;
49 list_t *outgoing_list = NULL;
50
51 /* Setup sockets */
52
53 static void configure_tcp(connection_t *c) {
54         int option;
55
56 #ifdef O_NONBLOCK
57         int flags = fcntl(c->socket, F_GETFL);
58
59         if(fcntl(c->socket, F_SETFL, flags | O_NONBLOCK) < 0) {
60                 logger(DEBUG_ALWAYS, LOG_ERR, "fcntl for %s: %s", c->hostname, strerror(errno));
61         }
62 #elif defined(WIN32)
63         unsigned long arg = 1;
64
65         if(ioctlsocket(c->socket, FIONBIO, &arg) != 0) {
66                 logger(DEBUG_ALWAYS, LOG_ERR, "ioctlsocket for %s: %d", c->hostname, sockstrerror(sockerrno));
67         }
68 #endif
69
70 #if defined(SOL_TCP) && defined(TCP_NODELAY)
71         option = 1;
72         setsockopt(c->socket, SOL_TCP, TCP_NODELAY, (void *)&option, sizeof option);
73 #endif
74
75 #if defined(SOL_IP) && defined(IP_TOS) && defined(IPTOS_LOWDELAY)
76         option = IPTOS_LOWDELAY;
77         setsockopt(c->socket, SOL_IP, IP_TOS, (void *)&option, sizeof option);
78 #endif
79 }
80
81 static bool bind_to_interface(int sd) {
82         char *iface;
83
84 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
85         struct ifreq ifr;
86         int status;
87 #endif /* defined(SOL_SOCKET) && defined(SO_BINDTODEVICE) */
88
89         if(!get_config_string (lookup_config (config_tree, "BindToInterface"), &iface))
90                 return true;
91
92 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
93         memset(&ifr, 0, sizeof(ifr));
94         strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
95         ifr.ifr_ifrn.ifrn_name[IFNAMSIZ - 1] = 0;
96
97         status = setsockopt(sd, SOL_SOCKET, SO_BINDTODEVICE, (void *)&ifr, sizeof(ifr));
98         if(status) {
99                 logger(DEBUG_ALWAYS, LOG_ERR, "Can't bind to interface %s: %s", iface,
100                                 strerror(errno));
101                 return false;
102         }
103 #else /* if !defined(SOL_SOCKET) || !defined(SO_BINDTODEVICE) */
104         logger(DEBUG_ALWAYS, LOG_WARNING, "%s not supported on this platform", "BindToInterface");
105 #endif
106
107         return true;
108 }
109
110 int setup_listen_socket(const sockaddr_t *sa) {
111         int nfd;
112         char *addrstr;
113         int option;
114         char *iface;
115
116         nfd = socket(sa->sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
117
118         if(nfd < 0) {
119                 logger(DEBUG_STATUS, LOG_ERR, "Creating metasocket failed: %s", sockstrerror(sockerrno));
120                 return -1;
121         }
122
123 #ifdef FD_CLOEXEC
124         fcntl(nfd, F_SETFD, FD_CLOEXEC);
125 #endif
126
127         /* Optimize TCP settings */
128
129         option = 1;
130         setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, (void *)&option, sizeof option);
131
132 #if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
133         if(sa->sa.sa_family == AF_INET6)
134                 setsockopt(nfd, SOL_IPV6, IPV6_V6ONLY, (void *)&option, sizeof option);
135 #endif
136
137         if(get_config_string
138            (lookup_config(config_tree, "BindToInterface"), &iface)) {
139 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
140                 struct ifreq ifr;
141
142                 memset(&ifr, 0, sizeof ifr);
143                 strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
144
145                 if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, (void *)&ifr, sizeof ifr)) {
146                         closesocket(nfd);
147                         logger(DEBUG_ALWAYS, LOG_ERR, "Can't bind to interface %s: %s", iface,
148                                    strerror(sockerrno));
149                         return -1;
150                 }
151 #else
152                 logger(DEBUG_ALWAYS, LOG_WARNING, "%s not supported on this platform", "BindToInterface");
153 #endif
154         }
155
156         if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
157                 closesocket(nfd);
158                 addrstr = sockaddr2hostname(sa);
159                 logger(DEBUG_ALWAYS, LOG_ERR, "Can't bind to %s/tcp: %s", addrstr, sockstrerror(sockerrno));
160                 free(addrstr);
161                 return -1;
162         }
163
164         if(listen(nfd, 3)) {
165                 closesocket(nfd);
166                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "listen", sockstrerror(sockerrno));
167                 return -1;
168         }
169
170         return nfd;
171 }
172
173 int setup_vpn_in_socket(const sockaddr_t *sa) {
174         int nfd;
175         char *addrstr;
176         int option;
177
178         nfd = socket(sa->sa.sa_family, SOCK_DGRAM, IPPROTO_UDP);
179
180         if(nfd < 0) {
181                 logger(DEBUG_ALWAYS, LOG_ERR, "Creating UDP socket failed: %s", sockstrerror(sockerrno));
182                 return -1;
183         }
184
185 #ifdef FD_CLOEXEC
186         fcntl(nfd, F_SETFD, FD_CLOEXEC);
187 #endif
188
189 #ifdef O_NONBLOCK
190         {
191                 int flags = fcntl(nfd, F_GETFL);
192
193                 if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0) {
194                         closesocket(nfd);
195                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "fcntl",
196                                    strerror(errno));
197                         return -1;
198                 }
199         }
200 #elif defined(WIN32)
201         {
202                 unsigned long arg = 1;
203                 if(ioctlsocket(nfd, FIONBIO, &arg) != 0) {
204                         closesocket(nfd);
205                         logger(DEBUG_ALWAYS, LOG_ERR, "Call to `%s' failed: %s", "ioctlsocket", sockstrerror(sockerrno));
206                         return -1;
207                 }
208         }
209 #endif
210
211         option = 1;
212         setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, (void *)&option, sizeof option);
213         setsockopt(nfd, SOL_SOCKET, SO_BROADCAST, (void *)&option, sizeof option);
214
215         if(udp_rcvbuf && setsockopt(nfd, SOL_SOCKET, SO_RCVBUF, (void *)&udp_rcvbuf, sizeof(udp_rcvbuf)))
216                 logger(DEBUG_ALWAYS, LOG_WARNING, "Can't set UDP SO_RCVBUF to %i: %s", udp_rcvbuf, strerror(errno));
217
218         if(udp_sndbuf && setsockopt(nfd, SOL_SOCKET, SO_SNDBUF, (void *)&udp_sndbuf, sizeof(udp_sndbuf)))
219                 logger(DEBUG_ALWAYS, LOG_WARNING, "Can't set UDP SO_SNDBUF to %i: %s", udp_sndbuf, strerror(errno));
220
221 #if defined(IPPROTO_IPV6) && defined(IPV6_V6ONLY)
222         if(sa->sa.sa_family == AF_INET6)
223                 setsockopt(nfd, IPPROTO_IPV6, IPV6_V6ONLY, (void *)&option, sizeof option);
224 #endif
225
226 #if defined(IP_DONTFRAG) && !defined(IP_DONTFRAGMENT)
227 #define IP_DONTFRAGMENT IP_DONTFRAG
228 #endif
229
230 #if defined(SOL_IP) && defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DO)
231         if(myself->options & OPTION_PMTU_DISCOVERY) {
232                 option = IP_PMTUDISC_DO;
233                 setsockopt(nfd, SOL_IP, IP_MTU_DISCOVER, (void *)&option, sizeof(option));
234         }
235 #elif defined(IPPROTO_IP) && defined(IP_DONTFRAGMENT)
236         if(myself->options & OPTION_PMTU_DISCOVERY) {
237                 option = 1;
238                 setsockopt(nfd, IPPROTO_IP, IP_DONTFRAGMENT, (void *)&option, sizeof(option));
239         }
240 #else
241 #warning No way to disable IPv4 fragmentation
242 #endif
243
244 #if defined(SOL_IPV6) && defined(IPV6_MTU_DISCOVER) && defined(IPV6_PMTUDISC_DO)
245         if(myself->options & OPTION_PMTU_DISCOVERY) {
246                 option = IPV6_PMTUDISC_DO;
247                 setsockopt(nfd, SOL_IPV6, IPV6_MTU_DISCOVER, (void *)&option, sizeof(option));
248         }
249 #elif defined(IPPROTO_IPV6) && defined(IPV6_DONTFRAG)
250         if(myself->options & OPTION_PMTU_DISCOVERY) {
251                 option = 1;
252                 setsockopt(nfd, IPPROTO_IPV6, IPV6_DONTFRAG, (void *)&option, sizeof(option));
253         }
254 #else
255 #warning No way to disable IPv6 fragmentation
256 #endif
257
258         if (!bind_to_interface(nfd)) {
259                 closesocket(nfd);
260                 return -1;
261         }
262
263         if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
264                 closesocket(nfd);
265                 addrstr = sockaddr2hostname(sa);
266                 logger(DEBUG_ALWAYS, LOG_ERR, "Can't bind to %s/udp: %s", addrstr, sockstrerror(sockerrno));
267                 free(addrstr);
268                 return -1;
269         }
270
271         return nfd;
272 } /* int setup_vpn_in_socket */
273
274 static void retry_outgoing_handler(int fd, short events, void *data) {
275         setup_outgoing_connection(data);
276 }
277
278 void retry_outgoing(outgoing_t *outgoing) {
279         outgoing->timeout += 5;
280
281         if(outgoing->timeout > maxtimeout)
282                 outgoing->timeout = maxtimeout;
283
284         timeout_set(&outgoing->ev, retry_outgoing_handler, outgoing);
285         event_add(&outgoing->ev, &(struct timeval){outgoing->timeout, 0});
286
287         logger(DEBUG_CONNECTIONS, LOG_NOTICE,
288                            "Trying to re-establish outgoing connection in %d seconds",
289                            outgoing->timeout);
290 }
291
292 void finish_connecting(connection_t *c) {
293         logger(DEBUG_CONNECTIONS, LOG_INFO, "Connected to %s (%s)", c->name, c->hostname);
294
295         configure_tcp(c);
296
297         c->last_ping_time = time(NULL);
298         c->status.connecting = false;
299
300         send_id(c);
301 }
302
303 bool do_outgoing_connection(connection_t *c) {
304         char *address, *port, *space;
305         int result;
306
307         if(!c->outgoing) {
308                 logger(DEBUG_ALWAYS, LOG_ERR, "do_outgoing_connection() for %s called without c->outgoing", c->name);
309                 abort();
310         }
311
312 begin:
313         if(!c->outgoing->ai) {
314                 if(!c->outgoing->cfg) {
315                         logger(DEBUG_CONNECTIONS, LOG_ERR, "Could not set up a meta connection to %s",
316                                            c->name);
317                         retry_outgoing(c->outgoing);
318                         c->outgoing = NULL;
319                         connection_del(c);
320                         return false;
321                 }
322
323                 get_config_string(c->outgoing->cfg, &address);
324
325                 space = strchr(address, ' ');
326                 if(space) {
327                         port = xstrdup(space + 1);
328                         *space = 0;
329                 } else {
330                         if(!get_config_string(lookup_config(c->config_tree, "Port"), &port))
331                                 port = xstrdup("655");
332                 }
333
334                 c->outgoing->ai = str2addrinfo(address, port, SOCK_STREAM);
335                 free(address);
336                 free(port);
337
338                 c->outgoing->aip = c->outgoing->ai;
339                 c->outgoing->cfg = lookup_config_next(c->config_tree, c->outgoing->cfg);
340         }
341
342         if(!c->outgoing->aip) {
343                 if(c->outgoing->ai)
344                         freeaddrinfo(c->outgoing->ai);
345                 c->outgoing->ai = NULL;
346                 goto begin;
347         }
348
349         memcpy(&c->address, c->outgoing->aip->ai_addr, c->outgoing->aip->ai_addrlen);
350         c->outgoing->aip = c->outgoing->aip->ai_next;
351
352         if(c->hostname)
353                 free(c->hostname);
354
355         c->hostname = sockaddr2hostname(&c->address);
356
357         logger(DEBUG_CONNECTIONS, LOG_INFO, "Trying to connect to %s (%s)", c->name,
358                            c->hostname);
359
360         c->socket = socket(c->address.sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
361
362 #ifdef FD_CLOEXEC
363         fcntl(c->socket, F_SETFD, FD_CLOEXEC);
364 #endif
365
366         if(c->socket == -1) {
367                 logger(DEBUG_CONNECTIONS, LOG_ERR, "Creating socket for %s failed: %s", c->hostname, sockstrerror(sockerrno));
368                 goto begin;
369         }
370
371 #if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
372         int option = 1;
373         if(c->address.sa.sa_family == AF_INET6)
374                 setsockopt(c->socket, SOL_IPV6, IPV6_V6ONLY, (void *)&option, sizeof option);
375 #endif
376
377         bind_to_interface(c->socket);
378
379         /* Optimize TCP settings */
380
381         configure_tcp(c);
382
383         /* Connect */
384
385         result = connect(c->socket, &c->address.sa, SALEN(c->address.sa));
386
387         if(result == -1) {
388                 if(sockinprogress(sockerrno)) {
389                         c->status.connecting = true;
390                         return true;
391                 }
392
393                 closesocket(c->socket);
394
395                 logger(DEBUG_CONNECTIONS, LOG_ERR, "%s: %s", c->hostname, sockstrerror(sockerrno));
396
397                 goto begin;
398         }
399
400         finish_connecting(c);
401
402         return true;
403 }
404
405 static void handle_meta_write(int sock, short events, void *data) {
406         connection_t *c = data;
407
408         ssize_t outlen = send(c->socket, c->outbuf.data + c->outbuf.offset, c->outbuf.len - c->outbuf.offset, 0);
409         if(outlen <= 0) {
410                 logger(DEBUG_ALWAYS, LOG_ERR, "Onoes, outlen = %d (%s)", (int)outlen, strerror(errno));
411                 terminate_connection(c, c->status.active);
412                 return;
413         }
414
415         buffer_read(&c->outbuf, outlen);
416         if(!c->outbuf.len && event_initialized(&c->outevent))
417                 event_del(&c->outevent);
418 }
419
420 void setup_outgoing_connection(outgoing_t *outgoing) {
421         connection_t *c;
422         node_t *n;
423
424         if(event_initialized(&outgoing->ev))
425                 event_del(&outgoing->ev);
426
427         n = lookup_node(outgoing->name);
428
429         if(n)
430                 if(n->connection) {
431                         logger(DEBUG_CONNECTIONS, LOG_INFO, "Already connected to %s", outgoing->name);
432
433                         n->connection->outgoing = outgoing;
434                         return;
435                 }
436
437         c = new_connection();
438         c->name = xstrdup(outgoing->name);
439         c->outcipher = myself->connection->outcipher;
440         c->outdigest = myself->connection->outdigest;
441         c->outmaclength = myself->connection->outmaclength;
442         c->outcompression = myself->connection->outcompression;
443
444         init_configuration(&c->config_tree);
445         read_connection_config(c);
446
447         outgoing->cfg = lookup_config(c->config_tree, "Address");
448
449         if(!outgoing->cfg) {
450                 logger(DEBUG_ALWAYS, LOG_ERR, "No address specified for %s", c->name);
451                 free_connection(c);
452                 return;
453         }
454
455         c->outgoing = outgoing;
456         c->last_ping_time = time(NULL);
457
458         connection_add(c);
459
460         if (do_outgoing_connection(c)) {
461                 event_set(&c->inevent, c->socket, EV_READ | EV_PERSIST, handle_meta_connection_data, c);
462                 event_set(&c->outevent, c->socket, EV_WRITE | EV_PERSIST, handle_meta_write, c);
463                 event_add(&c->inevent, NULL);
464         }
465 }
466
467 /*
468   accept a new tcp connect and create a
469   new connection
470 */
471 void handle_new_meta_connection(int sock, short events, void *data) {
472         connection_t *c;
473         sockaddr_t sa;
474         int fd;
475         socklen_t len = sizeof sa;
476
477         fd = accept(sock, &sa.sa, &len);
478
479         if(fd < 0) {
480                 logger(DEBUG_ALWAYS, LOG_ERR, "Accepting a new connection failed: %s", sockstrerror(sockerrno));
481                 return;
482         }
483
484         sockaddrunmap(&sa);
485
486         c = new_connection();
487         c->name = xstrdup("<unknown>");
488         c->outcipher = myself->connection->outcipher;
489         c->outdigest = myself->connection->outdigest;
490         c->outmaclength = myself->connection->outmaclength;
491         c->outcompression = myself->connection->outcompression;
492
493         c->address = sa;
494         c->hostname = sockaddr2hostname(&sa);
495         c->socket = fd;
496         c->last_ping_time = time(NULL);
497
498         logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Connection from %s", c->hostname);
499
500         event_set(&c->inevent, c->socket, EV_READ | EV_PERSIST, handle_meta_connection_data, c);
501         event_set(&c->outevent, c->socket, EV_WRITE | EV_PERSIST, handle_meta_write, c);
502         event_add(&c->inevent, NULL);
503                 
504         configure_tcp(c);
505
506         connection_add(c);
507
508         c->allow_request = ID;
509         send_id(c);
510 }
511
512 static void free_outgoing(outgoing_t *outgoing) {
513         if(outgoing->ai)
514                 freeaddrinfo(outgoing->ai);
515
516         if(outgoing->name)
517                 free(outgoing->name);
518
519         free(outgoing);
520 }
521
522 void try_outgoing_connections(void) {
523         static config_t *cfg = NULL;
524         char *name;
525         outgoing_t *outgoing;
526         
527         outgoing_list = list_alloc((list_action_t)free_outgoing);
528                         
529         for(cfg = lookup_config(config_tree, "ConnectTo"); cfg; cfg = lookup_config_next(config_tree, cfg)) {
530                 get_config_string(cfg, &name);
531
532                 if(!check_id(name)) {
533                         logger(DEBUG_ALWAYS, LOG_ERR,
534                                    "Invalid name for outgoing connection in %s line %d",
535                                    cfg->file, cfg->line);
536                         free(name);
537                         continue;
538                 }
539
540                 outgoing = xmalloc_and_zero(sizeof *outgoing);
541                 outgoing->name = name;
542                 list_insert_tail(outgoing_list, outgoing);
543                 setup_outgoing_connection(outgoing);
544         }
545 }