Extract common logic in OpenSSL-specific code
[tinc] / src / tincd.c
1 /*
2     tincd.c -- the main file for tincd
3     Copyright (C) 1998-2005 Ivo Timmermans
4                   2000-2022 Guus Sliepen <guus@tinc-vpn.org>
5                   2008      Max Rijevski <maksuf@gmail.com>
6                   2009      Michael Tokarev <mjt@tls.msk.ru>
7                   2010      Julien Muchembled <jm@jmuchemb.eu>
8                   2010      Timothy Redaelli <timothy@redaelli.eu>
9
10     This program is free software; you can redistribute it and/or modify
11     it under the terms of the GNU General Public License as published by
12     the Free Software Foundation; either version 2 of the License, or
13     (at your option) any later version.
14
15     This program is distributed in the hope that it will be useful,
16     but WITHOUT ANY WARRANTY; without even the implied warranty of
17     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18     GNU General Public License for more details.
19
20     You should have received a copy of the GNU General Public License along
21     with this program; if not, write to the Free Software Foundation, Inc.,
22     51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
23 */
24
25 #include "system.h"
26
27 /* Darwin (MacOS/X) needs the following definition... */
28 #ifndef _P1003_1B_VISIBLE
29 #define _P1003_1B_VISIBLE
30 #endif
31
32 #ifdef HAVE_SYS_MMAN_H
33 #include <sys/mman.h>
34 #endif
35
36 #ifdef HAVE_LZO
37 #include LZO1X_H
38 #endif
39
40 #ifdef LZ4_H
41 #include LZ4_H
42 #endif
43
44 #ifndef HAVE_MINGW
45 #include <pwd.h>
46 #include <grp.h>
47 #include <time.h>
48 #endif
49
50 #include "conf.h"
51 #include "crypto.h"
52 #include "event.h"
53 #include "logger.h"
54 #include "names.h"
55 #include "net.h"
56 #include "process.h"
57 #include "protocol.h"
58 #include "utils.h"
59 #include "xalloc.h"
60 #include "version.h"
61
62 /* If nonzero, display usage information and exit. */
63 static bool show_help = false;
64
65 /* If nonzero, print the version on standard output and exit.  */
66 static bool show_version = false;
67
68 /* If nonzero, use null ciphers and skip all key exchanges. */
69 bool bypass_security = false;
70
71 #ifdef HAVE_MLOCKALL
72 /* If nonzero, disable swapping for this process. */
73 static bool do_mlock = false;
74 #endif
75
76 #ifndef HAVE_MINGW
77 /* If nonzero, chroot to netdir after startup. */
78 static bool do_chroot = false;
79
80 /* If !NULL, do setuid to given user after startup */
81 static const char *switchuser = NULL;
82 #endif
83
84 /* If nonzero, write log entries to a separate file. */
85 bool use_logfile = false;
86
87 /* If nonzero, use syslog instead of stderr in no-detach mode. */
88 bool use_syslog = false;
89
90 char **g_argv;                  /* a copy of the cmdline arguments */
91
92 static int status = 1;
93
94 static struct option const long_options[] = {
95         {"config", required_argument, NULL, 'c'},
96         {"net", required_argument, NULL, 'n'},
97         {"help", no_argument, NULL, 1},
98         {"version", no_argument, NULL, 2},
99         {"no-detach", no_argument, NULL, 'D'},
100         {"debug", optional_argument, NULL, 'd'},
101         {"bypass-security", no_argument, NULL, 3},
102         {"mlock", no_argument, NULL, 'L'},
103         {"chroot", no_argument, NULL, 'R'},
104         {"user", required_argument, NULL, 'U'},
105         {"logfile", optional_argument, NULL, 4},
106         {"syslog", no_argument, NULL, 's'},
107         {"pidfile", required_argument, NULL, 5},
108         {"option", required_argument, NULL, 'o'},
109         {NULL, 0, NULL, 0}
110 };
111
112 #ifdef HAVE_MINGW
113 static struct WSAData wsa_state;
114 int main2(int argc, char **argv);
115 #endif
116
117 static void usage(bool status) {
118         if(status)
119                 fprintf(stderr, "Try `%s --help\' for more information.\n",
120                         program_name);
121         else {
122                 static const char *message =
123                         "Usage: %s [option]...\n"
124                         "\n"
125                         "  -c, --config=DIR              Read configuration options from DIR.\n"
126                         "  -D, --no-detach               Don't fork and detach.\n"
127                         "  -d, --debug[=LEVEL]           Increase debug level or set it to LEVEL.\n"
128                         "  -n, --net=NETNAME             Connect to net NETNAME.\n"
129 #ifdef HAVE_MLOCKALL
130                         "  -L, --mlock                   Lock tinc into main memory.\n"
131 #endif
132                         "      --logfile[=FILENAME]      Write log entries to a logfile.\n"
133                         "  -s  --syslog                  Use syslog instead of stderr with --no-detach.\n"
134                         "      --pidfile=FILENAME        Write PID and control socket cookie to FILENAME.\n"
135                         "      --bypass-security         Disables meta protocol security, for debugging.\n"
136                         "  -o, --option[HOST.]KEY=VALUE  Set global/host configuration value.\n"
137 #ifndef HAVE_MINGW
138                         "  -R, --chroot                  chroot to NET dir at startup.\n"
139                         "  -U, --user=USER               setuid to given USER at startup.\n"
140 #endif
141                         "      --help                    Display this help and exit.\n"
142                         "      --version                 Output version information and exit.\n"
143                         "\n"
144                         "Report bugs to tinc@tinc-vpn.org.\n";
145
146                 printf(message, program_name);
147         }
148 }
149
150 static bool parse_options(int argc, char **argv) {
151         config_t *cfg;
152         int r;
153         int option_index = 0;
154         int lineno = 0;
155
156         while((r = getopt_long(argc, argv, "c:DLd::n:so:RU:", long_options, &option_index)) != EOF) {
157                 switch(r) {
158                 case 0:   /* long option */
159                         break;
160
161                 case 'c': /* config file */
162                         free(confbase);
163                         confbase = xstrdup(optarg);
164                         break;
165
166                 case 'D': /* no detach */
167                         do_detach = false;
168                         break;
169
170                 case 'L': /* no detach */
171 #ifndef HAVE_MLOCKALL
172                         logger(DEBUG_ALWAYS, LOG_ERR, "The %s option is not supported on this platform.", argv[optind - 1]);
173                         goto exit_fail;
174 #else
175                         do_mlock = true;
176                         break;
177 #endif
178
179                 case 'd': /* increase debug level */
180                         if(!optarg && optind < argc && *argv[optind] != '-') {
181                                 optarg = argv[optind++];
182                         }
183
184                         if(optarg) {
185                                 debug_level = atoi(optarg);
186                         } else {
187                                 debug_level++;
188                         }
189
190                         break;
191
192                 case 'n': /* net name given */
193                         free(netname);
194                         netname = xstrdup(optarg);
195                         break;
196
197                 case 's': /* syslog */
198                         use_logfile = false;
199                         use_syslog = true;
200                         break;
201
202                 case 'o': /* option */
203                         cfg = parse_config_line(optarg, NULL, ++lineno);
204
205                         if(!cfg) {
206                                 goto exit_fail;
207                         }
208
209                         list_insert_tail(&cmdline_conf, cfg);
210                         break;
211
212 #ifdef HAVE_MINGW
213
214                 case 'R':
215                 case 'U':
216                         logger(DEBUG_ALWAYS, LOG_ERR, "The %s option is not supported on this platform.", argv[optind - 1]);
217                         goto exit_fail;
218 #else
219
220                 case 'R': /* chroot to NETNAME dir */
221                         do_chroot = true;
222                         break;
223
224                 case 'U': /* setuid to USER */
225                         switchuser = optarg;
226                         break;
227 #endif
228
229                 case 1:   /* show help */
230                         show_help = true;
231                         break;
232
233                 case 2:   /* show version */
234                         show_version = true;
235                         break;
236
237                 case 3:   /* bypass security */
238                         bypass_security = true;
239                         break;
240
241                 case 4:   /* write log entries to a file */
242                         use_syslog = false;
243                         use_logfile = true;
244
245                         if(!optarg && optind < argc && *argv[optind] != '-') {
246                                 optarg = argv[optind++];
247                         }
248
249                         if(optarg) {
250                                 free(logfilename);
251                                 logfilename = xstrdup(optarg);
252                         }
253
254                         break;
255
256                 case 5:   /* open control socket here */
257                         free(pidfilename);
258                         pidfilename = xstrdup(optarg);
259                         break;
260
261                 case '?': /* wrong options */
262                         usage(true);
263                         goto exit_fail;
264
265                 default:
266                         break;
267                 }
268         }
269
270         if(optind < argc) {
271                 fprintf(stderr, "%s: unrecognized argument '%s'\n", argv[0], argv[optind]);
272                 usage(true);
273                 goto exit_fail;
274         }
275
276         if(!netname && (netname = getenv("NETNAME"))) {
277                 netname = xstrdup(netname);
278         }
279
280         /* netname "." is special: a "top-level name" */
281
282         if(netname && (!*netname || !strcmp(netname, "."))) {
283                 free(netname);
284                 netname = NULL;
285         }
286
287         if(netname && !check_netname(netname, false)) {
288                 fprintf(stderr, "Invalid character in netname!\n");
289                 goto exit_fail;
290         }
291
292         if(netname && !check_netname(netname, true)) {
293                 fprintf(stderr, "Warning: unsafe character in netname!\n");
294         }
295
296         return true;
297
298 exit_fail:
299         free_names();
300         list_empty_list(&cmdline_conf);
301         return false;
302 }
303
304 static bool drop_privs(void) {
305 #ifndef HAVE_MINGW
306         uid_t uid = 0;
307
308         if(switchuser) {
309                 struct passwd *pw = getpwnam(switchuser);
310
311                 if(!pw) {
312                         logger(DEBUG_ALWAYS, LOG_ERR, "unknown user `%s'", switchuser);
313                         return false;
314                 }
315
316                 uid = pw->pw_uid;
317
318                 // The second parameter to initgroups on macOS requires int,
319                 // but __gid_t is unsigned int. There's not much we can do here.
320                 if(initgroups(switchuser, pw->pw_gid) != 0 || // NOLINT(bugprone-narrowing-conversions)
321                                 setgid(pw->pw_gid) != 0) {
322                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
323                                "initgroups", strerror(errno));
324                         return false;
325                 }
326
327 #ifndef __ANDROID__
328 // Not supported in android NDK
329                 endgrent();
330                 endpwent();
331 #endif
332         }
333
334         if(do_chroot) {
335                 tzset();        /* for proper timestamps in logs */
336
337                 if(chroot(confbase) != 0 || chdir("/") != 0) {
338                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
339                                "chroot", strerror(errno));
340                         return false;
341                 }
342
343                 free(confbase);
344                 confbase = xstrdup("");
345         }
346
347         if(switchuser)
348                 if(setuid(uid) != 0) {
349                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
350                                "setuid", strerror(errno));
351                         return false;
352                 }
353
354 #endif
355         return true;
356 }
357
358 #ifdef HAVE_MINGW
359 # define setpriority(level) !SetPriorityClass(GetCurrentProcess(), (level))
360
361 static void stop_handler(void *data, int flags) {
362         (void)data;
363         (void)flags;
364
365         event_exit();
366 }
367
368 static BOOL WINAPI console_ctrl_handler(DWORD type) {
369         (void)type;
370
371         logger(DEBUG_ALWAYS, LOG_NOTICE, "Got console shutdown request");
372
373         if(WSASetEvent(stop_io.event) == FALSE) {
374                 abort();
375         }
376
377         return TRUE;
378 }
379 #else
380 # define NORMAL_PRIORITY_CLASS 0
381 # define BELOW_NORMAL_PRIORITY_CLASS 10
382 # define HIGH_PRIORITY_CLASS -10
383 # define setpriority(level) (setpriority(PRIO_PROCESS, 0, (level)))
384 #endif
385
386 static void cleanup(void) {
387         splay_empty_tree(&config_tree);
388         list_empty_list(&cmdline_conf);
389         free_names();
390 }
391
392 int main(int argc, char **argv) {
393         program_name = argv[0];
394
395         if(!parse_options(argc, argv)) {
396                 return 1;
397         }
398
399         if(show_version) {
400                 static const char *message =
401                         "%s version %s (built %s %s, protocol %d.%d)\n"
402                         "Features:"
403 #ifdef HAVE_OPENSSL
404                         " openssl"
405 #endif
406 #ifdef HAVE_LIBGCRYPT
407                         " libgcrypt"
408 #endif
409 #ifdef HAVE_LZO
410                         " comp_lzo"
411 #endif
412 #ifdef HAVE_ZLIB
413                         " comp_zlib"
414 #endif
415 #ifdef HAVE_LZ4
416                         " comp_lz4"
417 #endif
418 #ifndef DISABLE_LEGACY
419                         " legacy_protocol"
420 #endif
421 #ifdef ENABLE_JUMBOGRAMS
422                         " jumbograms"
423 #endif
424 #ifdef ENABLE_TUNEMU
425                         " tunemu"
426 #endif
427 #ifdef HAVE_MINIUPNPC
428                         " miniupnpc"
429 #endif
430 #ifdef ENABLE_UML
431                         " uml"
432 #endif
433 #ifdef ENABLE_VDE
434                         " vde"
435 #endif
436                         "\n\n"
437                         "Copyright (C) 1998-2021 Ivo Timmermans, Guus Sliepen and others.\n"
438                         "See the AUTHORS file for a complete list.\n"
439                         "\n"
440                         "tinc comes with ABSOLUTELY NO WARRANTY.  This is free software,\n"
441                         "and you are welcome to redistribute it under certain conditions;\n"
442                         "see the file COPYING for details.\n";
443
444                 printf(message, PACKAGE, BUILD_VERSION, BUILD_DATE, BUILD_TIME, PROT_MAJOR, PROT_MINOR);
445                 return 0;
446         }
447
448         if(show_help) {
449                 usage(false);
450                 return 0;
451         }
452
453         make_names(true);
454         atexit(cleanup);
455
456         if(chdir(confbase) == -1) {
457                 logger(DEBUG_ALWAYS, LOG_ERR, "Could not change to configuration directory: %s", strerror(errno));
458                 return 1;
459         }
460
461 #ifdef HAVE_MINGW
462
463         if(WSAStartup(MAKEWORD(2, 2), &wsa_state)) {
464                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "WSAStartup", winerror(GetLastError()));
465                 return 1;
466         }
467
468 #else
469         // Check if we got an umbilical fd from the process that started us
470         char *umbstr = getenv("TINC_UMBILICAL");
471
472         if(umbstr) {
473                 umbilical = atoi(umbstr);
474
475                 if(fcntl(umbilical, F_GETFL) < 0) {
476                         umbilical = 0;
477                 }
478
479 #ifdef FD_CLOEXEC
480
481                 if(umbilical) {
482                         fcntl(umbilical, F_SETFD, FD_CLOEXEC);
483                 }
484
485 #endif
486         }
487
488 #endif
489
490         openlogger("tinc", use_logfile ? LOGMODE_FILE : LOGMODE_STDERR);
491
492         g_argv = argv;
493
494         if(getenv("LISTEN_PID") && atoi(getenv("LISTEN_PID")) == getpid()) {
495                 do_detach = false;
496         }
497
498 #ifdef HAVE_UNSETENV
499         unsetenv("LISTEN_PID");
500 #endif
501
502         gettimeofday(&now, NULL);
503         crypto_init();
504         prng_init();
505
506         if(!read_server_config(&config_tree)) {
507                 return 1;
508         }
509
510         if(debug_level == DEBUG_NOTHING) {
511                 int level = 0;
512
513                 if(get_config_int(lookup_config(&config_tree, "LogLevel"), &level)) {
514                         debug_level = level;
515                 }
516         }
517
518 #ifdef HAVE_LZO
519
520         if(lzo_init() != LZO_E_OK) {
521                 logger(DEBUG_ALWAYS, LOG_ERR, "Error initializing LZO compressor!");
522                 return 1;
523         }
524
525 #endif
526
527 #ifdef HAVE_MINGW
528         io_add_event(&stop_io, stop_handler, NULL, WSACreateEvent());
529
530         if(stop_io.event == FALSE) {
531                 abort();
532         }
533
534         int result;
535
536         if(!do_detach || !init_service()) {
537                 SetConsoleCtrlHandler(console_ctrl_handler, TRUE);
538                 result = main2(argc, argv);
539         } else {
540                 result = 1;
541         }
542
543         if(WSACloseEvent(stop_io.event) == FALSE) {
544                 abort();
545         }
546
547         io_del(&stop_io);
548         return result;
549 }
550
551 int main2(int argc, char **argv) {
552         (void)argc;
553         (void)argv;
554 #endif
555         char *priority = NULL;
556
557         if(!detach()) {
558                 return 1;
559         }
560
561 #ifdef HAVE_MLOCKALL
562
563         /* Lock all pages into memory if requested.
564          * This has to be done after daemon()/fork() so it works for child.
565          * No need to do that in parent as it's very short-lived. */
566         if(do_mlock && mlockall(MCL_CURRENT | MCL_FUTURE) != 0) {
567                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "mlockall",
568                        strerror(errno));
569                 return 1;
570         }
571
572 #endif
573
574         /* Setup sockets and open device. */
575
576         if(!setup_network()) {
577                 goto end;
578         }
579
580         /* Change process priority */
581
582         if(get_config_string(lookup_config(&config_tree, "ProcessPriority"), &priority)) {
583                 if(!strcasecmp(priority, "Normal")) {
584                         if(setpriority(NORMAL_PRIORITY_CLASS) != 0) {
585                                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setpriority", strerror(errno));
586                                 goto end;
587                         }
588                 } else if(!strcasecmp(priority, "Low")) {
589                         if(setpriority(BELOW_NORMAL_PRIORITY_CLASS) != 0) {
590                                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setpriority", strerror(errno));
591                                 goto end;
592                         }
593                 } else if(!strcasecmp(priority, "High")) {
594                         if(setpriority(HIGH_PRIORITY_CLASS) != 0) {
595                                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setpriority", strerror(errno));
596                                 goto end;
597                         }
598                 } else {
599                         logger(DEBUG_ALWAYS, LOG_ERR, "Invalid priority `%s`!", priority);
600                         goto end;
601                 }
602         }
603
604         /* drop privileges */
605         if(!drop_privs()) {
606                 goto end;
607         }
608
609         /* Start main loop. It only exits when tinc is killed. */
610
611         logger(DEBUG_ALWAYS, LOG_NOTICE, "Ready");
612
613         if(umbilical) { // snip!
614                 if(write(umbilical, "", 1) != 1) {
615                         // Pipe full or broken, nothing we can do about it.
616                 }
617
618                 close(umbilical);
619                 umbilical = 0;
620         }
621
622         try_outgoing_connections();
623
624         status = main_loop();
625
626         /* Shutdown properly. */
627
628 end:
629         close_network_connections();
630
631         logger(DEBUG_ALWAYS, LOG_NOTICE, "Terminating");
632
633         free(priority);
634
635         crypto_exit();
636
637         return status;
638 }