Remove the warnings when IP_DONTFRAGMENT/IPV6-DONTFRAG is not supported.
[tinc] / src / tincd.c
1 /*
2     tincd.c -- the main file for tincd
3     Copyright (C) 1998-2005 Ivo Timmermans
4                   2000-2013 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 #include <openssl/rand.h>
37 #include <openssl/rsa.h>
38 #include <openssl/pem.h>
39 #include <openssl/evp.h>
40 #include <openssl/engine.h>
41
42 #ifdef HAVE_LZO
43 #include LZO1X_H
44 #endif
45
46 #ifndef HAVE_MINGW
47 #include <pwd.h>
48 #include <grp.h>
49 #include <time.h>
50 #endif
51
52 #include <getopt.h>
53 #include "pidfile.h"
54
55 #include "conf.h"
56 #include "device.h"
57 #include "logger.h"
58 #include "net.h"
59 #include "netutl.h"
60 #include "process.h"
61 #include "protocol.h"
62 #include "utils.h"
63 #include "xalloc.h"
64
65 /* The name this program was run with. */
66 char *program_name = NULL;
67
68 /* If nonzero, display usage information and exit. */
69 bool show_help = false;
70
71 /* If nonzero, print the version on standard output and exit.  */
72 bool show_version = false;
73
74 /* If nonzero, it will attempt to kill a running tincd and exit. */
75 int kill_tincd = 0;
76
77 /* If nonzero, generate public/private keypair for this host/net. */
78 int generate_keys = 0;
79
80 /* If nonzero, use null ciphers and skip all key exchanges. */
81 bool bypass_security = false;
82
83 /* If nonzero, disable swapping for this process. */
84 bool do_mlock = false;
85
86 /* If nonzero, chroot to netdir after startup. */
87 static bool do_chroot = false;
88
89 /* If !NULL, do setuid to given user after startup */
90 static const char *switchuser = NULL;
91
92 /* If nonzero, write log entries to a separate file. */
93 bool use_logfile = false;
94
95 char *identname = NULL;                         /* program name for syslog */
96 char *pidfilename = NULL;                       /* pid file location */
97 char *logfilename = NULL;                       /* log file location */
98 char **g_argv;                                  /* a copy of the cmdline arguments */
99
100 static int status;
101
102 static struct option const long_options[] = {
103         {"config", required_argument, NULL, 'c'},
104         {"kill", optional_argument, NULL, 'k'},
105         {"net", required_argument, NULL, 'n'},
106         {"help", no_argument, NULL, 1},
107         {"version", no_argument, NULL, 2},
108         {"no-detach", no_argument, NULL, 'D'},
109         {"generate-keys", optional_argument, NULL, 'K'},
110         {"debug", optional_argument, NULL, 'd'},
111         {"bypass-security", no_argument, NULL, 3},
112         {"mlock", no_argument, NULL, 'L'},
113         {"chroot", no_argument, NULL, 'R'},
114         {"user", required_argument, NULL, 'U'},
115         {"logfile", optional_argument, NULL, 4},
116         {"pidfile", required_argument, NULL, 5},
117         {"option", required_argument, NULL, 'o'},
118         {NULL, 0, NULL, 0}
119 };
120
121 #ifdef HAVE_MINGW
122 static struct WSAData wsa_state;
123 CRITICAL_SECTION mutex;
124 int main2(int argc, char **argv);
125 #endif
126
127 static void usage(bool status) {
128         if(status)
129                 fprintf(stderr, "Try `%s --help\' for more information.\n",
130                                 program_name);
131         else {
132                 printf("Usage: %s [option]...\n\n", program_name);
133                 printf("  -c, --config=DIR               Read configuration options from DIR.\n"
134                                 "  -D, --no-detach                Don't fork and detach.\n"
135                                 "  -d, --debug[=LEVEL]            Increase debug level or set it to LEVEL.\n"
136                                 "  -k, --kill[=SIGNAL]            Attempt to kill a running tincd and exit.\n"
137                                 "  -n, --net=NETNAME              Connect to net NETNAME.\n"
138                                 "  -K, --generate-keys[=BITS]     Generate public/private RSA keypair.\n"
139                                 "  -L, --mlock                    Lock tinc into main memory.\n"
140                                 "      --logfile[=FILENAME]       Write log entries to a logfile.\n"
141                                 "      --pidfile=FILENAME         Write PID to FILENAME.\n"
142                                 "  -o, --option=[HOST.]KEY=VALUE  Set global/host configuration value.\n"
143                                 "  -R, --chroot                   chroot to NET dir at startup.\n"
144                                 "  -U, --user=USER                setuid to given USER at startup.\n"
145                                 "      --help                     Display this help and exit.\n"
146                                 "      --version                  Output version information and exit.\n\n");
147                 printf("Report bugs to tinc@tinc-vpn.org.\n");
148         }
149 }
150
151 static bool parse_options(int argc, char **argv) {
152         config_t *cfg;
153         int r;
154         int option_index = 0;
155         int lineno = 0;
156
157         cmdline_conf = list_alloc((list_action_t)free_config);
158
159         while((r = getopt_long(argc, argv, "c:DLd::k::n:o:K::RU:", long_options, &option_index)) != EOF) {
160                 switch (r) {
161                         case 0:                         /* long option */
162                                 break;
163
164                         case 'c':                               /* config file */
165                                 if(confbase) {
166                                         fprintf(stderr, "Only one configuration directory can be given.\n");
167                                         usage(true);
168                                         return false;
169                                 }
170                                 confbase = xstrdup(optarg);
171                                 break;
172
173                         case 'D':                               /* no detach */
174                                 do_detach = false;
175                                 break;
176
177                         case 'L':                               /* no detach */
178 #ifndef HAVE_MLOCKALL
179                                 logger(LOG_ERR, "%s not supported on this platform", "mlockall()");
180                                 return false;
181 #else
182                                 do_mlock = true;
183                                 break;
184 #endif
185
186                         case 'd':                               /* increase debug level */
187                                 if(!optarg && optind < argc && *argv[optind] != '-')
188                                         optarg = argv[optind++];
189                                 if(optarg)
190                                         debug_level = atoi(optarg);
191                                 else
192                                         debug_level++;
193                                 break;
194
195                         case 'k':                               /* kill old tincds */
196 #ifndef HAVE_MINGW
197                                 if(!optarg && optind < argc && *argv[optind] != '-')
198                                         optarg = argv[optind++];
199                                 if(optarg) {
200                                         if(!strcasecmp(optarg, "HUP"))
201                                                 kill_tincd = SIGHUP;
202                                         else if(!strcasecmp(optarg, "TERM"))
203                                                 kill_tincd = SIGTERM;
204                                         else if(!strcasecmp(optarg, "KILL"))
205                                                 kill_tincd = SIGKILL;
206                                         else if(!strcasecmp(optarg, "USR1"))
207                                                 kill_tincd = SIGUSR1;
208                                         else if(!strcasecmp(optarg, "USR2"))
209                                                 kill_tincd = SIGUSR2;
210                                         else if(!strcasecmp(optarg, "WINCH"))
211                                                 kill_tincd = SIGWINCH;
212                                         else if(!strcasecmp(optarg, "INT"))
213                                                 kill_tincd = SIGINT;
214                                         else if(!strcasecmp(optarg, "ALRM"))
215                                                 kill_tincd = SIGALRM;
216                                         else if(!strcasecmp(optarg, "ABRT"))
217                                                 kill_tincd = SIGABRT;
218                                         else {
219                                                 kill_tincd = atoi(optarg);
220
221                                                 if(!kill_tincd) {
222                                                         fprintf(stderr, "Invalid argument `%s'; SIGNAL must be a number or one of HUP, TERM, KILL, USR1, USR2, WINCH, INT or ALRM.\n",
223                                                                         optarg);
224                                                         usage(true);
225                                                         return false;
226                                                 }
227                                         }
228                                 } else
229                                         kill_tincd = SIGTERM;
230 #else
231                                         kill_tincd = 1;
232 #endif
233                                 break;
234
235                         case 'n':                               /* net name given */
236                                 /* netname "." is special: a "top-level name" */
237                                 if(netname) {
238                                         fprintf(stderr, "Only one netname can be given.\n");
239                                         usage(true);
240                                         return false;
241                                 }
242                                 netname = strcmp(optarg, ".") != 0 ? xstrdup(optarg) : NULL;
243                                 break;
244
245                         case 'o':                               /* option */
246                                 cfg = parse_config_line(optarg, NULL, ++lineno);
247                                 if (!cfg)
248                                         return false;
249                                 list_insert_tail(cmdline_conf, cfg);
250                                 break;
251
252                         case 'K':                               /* generate public/private keypair */
253                                 if(!optarg && optind < argc && *argv[optind] != '-')
254                                         optarg = argv[optind++];
255                                 if(optarg) {
256                                         generate_keys = atoi(optarg);
257
258                                         if(generate_keys < 512) {
259                                                 fprintf(stderr, "Invalid argument `%s'; BITS must be a number equal to or greater than 512.\n",
260                                                                 optarg);
261                                                 usage(true);
262                                                 return false;
263                                         }
264
265                                         generate_keys &= ~7;    /* Round it to bytes */
266                                 } else
267                                         generate_keys = 2048;
268                                 break;
269
270                         case 'R':                               /* chroot to NETNAME dir */
271                                 do_chroot = true;
272                                 break;
273
274                         case 'U':                               /* setuid to USER */
275                                 switchuser = optarg;
276                                 break;
277
278                         case 1:                                 /* show help */
279                                 show_help = true;
280                                 break;
281
282                         case 2:                                 /* show version */
283                                 show_version = true;
284                                 break;
285
286                         case 3:                                 /* bypass security */
287                                 bypass_security = true;
288                                 break;
289
290                         case 4:                                 /* write log entries to a file */
291                                 use_logfile = true;
292                                 if(!optarg && optind < argc && *argv[optind] != '-')
293                                         optarg = argv[optind++];
294                                 if(optarg) {
295                                         if(logfilename) {
296                                                 fprintf(stderr, "Only one logfile can be given.\n");
297                                                 usage(true);
298                                                 return false;
299                                         }
300                                         logfilename = xstrdup(optarg);
301                                 }
302                                 break;
303
304                         case 5:                                 /* write PID to a file */
305                                 if(pidfilename) {
306                                         fprintf(stderr, "Only one pidfile can be given.\n");
307                                         usage(true);
308                                         return false;
309                                 }
310                                 pidfilename = xstrdup(optarg);
311                                 break;
312
313                         case '?':
314                                 usage(true);
315                                 return false;
316
317                         default:
318                                 break;
319                 }
320         }
321
322         if(optind < argc) {
323                 fprintf(stderr, "%s: unrecognized argument '%s'\n", argv[0], argv[optind]);
324                 usage(true);
325                 return false;
326         }
327
328         return true;
329 }
330
331 /* This function prettyprints the key generation process */
332
333 static void indicator(int a, int b, void *p) {
334         switch (a) {
335                 case 0:
336                         fprintf(stderr, ".");
337                         break;
338
339                 case 1:
340                         fprintf(stderr, "+");
341                         break;
342
343                 case 2:
344                         fprintf(stderr, "-");
345                         break;
346
347                 case 3:
348                         switch (b) {
349                                 case 0:
350                                         fprintf(stderr, " p\n");
351                                         break;
352
353                                 case 1:
354                                         fprintf(stderr, " q\n");
355                                         break;
356
357                                 default:
358                                         fprintf(stderr, "?");
359                         }
360                         break;
361
362                 default:
363                         fprintf(stderr, "?");
364         }
365 }
366
367 /*
368   Generate a public/private RSA keypair, and ask for a file to store
369   them in.
370 */
371 static bool keygen(int bits) {
372         RSA *rsa_key;
373         FILE *f;
374         char *pubname, *privname;
375
376         fprintf(stderr, "Generating %d bits keys:\n", bits);
377         rsa_key = RSA_generate_key(bits, 0x10001, indicator, NULL);
378
379         if(!rsa_key) {
380                 fprintf(stderr, "Error during key generation!\n");
381                 return false;
382         } else
383                 fprintf(stderr, "Done.\n");
384
385         xasprintf(&privname, "%s/rsa_key.priv", confbase);
386         f = ask_and_open(privname, "private RSA key");
387         free(privname);
388
389         if(!f)
390                 return false;
391
392 #ifdef HAVE_FCHMOD
393         /* Make it unreadable for others. */
394         fchmod(fileno(f), 0600);
395 #endif
396                 
397         fputc('\n', f);
398         PEM_write_RSAPrivateKey(f, rsa_key, NULL, NULL, 0, NULL, NULL);
399         fclose(f);
400
401         char *name = get_name();
402
403         if(name) {
404                 xasprintf(&pubname, "%s/hosts/%s", confbase, name);
405                 free(name);
406         } else {
407                 xasprintf(&pubname, "%s/rsa_key.pub", confbase);
408         }
409
410         f = ask_and_open(pubname, "public RSA key");
411         free(pubname);
412
413         if(!f)
414                 return false;
415
416         fputc('\n', f);
417         PEM_write_RSAPublicKey(f, rsa_key);
418         fclose(f);
419
420         return true;
421 }
422
423 /*
424   Set all files and paths according to netname
425 */
426 static void make_names(void) {
427 #ifdef HAVE_MINGW
428         HKEY key;
429         char installdir[1024] = "";
430         DWORD len = sizeof(installdir);
431 #endif
432
433         if(netname)
434                 xasprintf(&identname, "tinc.%s", netname);
435         else
436                 identname = xstrdup("tinc");
437
438 #ifdef HAVE_MINGW
439         if(!RegOpenKeyEx(HKEY_LOCAL_MACHINE, "SOFTWARE\\tinc", 0, KEY_READ, &key)) {
440                 if(!RegQueryValueEx(key, NULL, 0, 0, (LPBYTE)installdir, &len)) {
441                         if(!logfilename)
442                                 xasprintf(&logfilename, "%s/log/%s.log", identname);
443                         if(!confbase) {
444                                 if(netname)
445                                         xasprintf(&confbase, "%s/%s", installdir, netname);
446                                 else
447                                         xasprintf(&confbase, "%s", installdir);
448                         }
449                 }
450                 RegCloseKey(key);
451                 if(*installdir)
452                         return;
453         }
454 #endif
455
456         if(!pidfilename)
457                 xasprintf(&pidfilename, LOCALSTATEDIR "/run/%s.pid", identname);
458
459         if(!logfilename)
460                 xasprintf(&logfilename, LOCALSTATEDIR "/log/%s.log", identname);
461
462         if(netname) {
463                 if(!confbase)
464                         xasprintf(&confbase, CONFDIR "/tinc/%s", netname);
465                 else
466                         logger(LOG_INFO, "Both netname and configuration directory given, using the latter...");
467         } else {
468                 if(!confbase)
469                         xasprintf(&confbase, CONFDIR "/tinc");
470         }
471 }
472
473 static void free_names() {
474         if (identname) free(identname);
475         if (netname) free(netname);
476         if (pidfilename) free(pidfilename);
477         if (logfilename) free(logfilename);
478         if (confbase) free(confbase);
479 }
480
481 static bool drop_privs() {
482 #ifdef HAVE_MINGW
483         if (switchuser) {
484                 logger(LOG_ERR, "%s not supported on this platform", "-U");
485                 return false;
486         }
487         if (do_chroot) {
488                 logger(LOG_ERR, "%s not supported on this platform", "-R");
489                 return false;
490         }
491 #else
492         uid_t uid = 0;
493         if (switchuser) {
494                 struct passwd *pw = getpwnam(switchuser);
495                 if (!pw) {
496                         logger(LOG_ERR, "unknown user `%s'", switchuser);
497                         return false;
498                 }
499                 uid = pw->pw_uid;
500                 if (initgroups(switchuser, pw->pw_gid) != 0 ||
501                     setgid(pw->pw_gid) != 0) {
502                         logger(LOG_ERR, "System call `%s' failed: %s",
503                                "initgroups", strerror(errno));
504                         return false;
505                 }
506 #ifndef __ANDROID__
507 // Not supported in android NDK
508                 endgrent();
509                 endpwent();
510 #endif
511         }
512         if (do_chroot) {
513                 tzset();        /* for proper timestamps in logs */
514                 if (chroot(confbase) != 0 || chdir("/") != 0) {
515                         logger(LOG_ERR, "System call `%s' failed: %s",
516                                "chroot", strerror(errno));
517                         return false;
518                 }
519                 free(confbase);
520                 confbase = xstrdup("");
521         }
522         if (switchuser)
523                 if (setuid(uid) != 0) {
524                         logger(LOG_ERR, "System call `%s' failed: %s",
525                                "setuid", strerror(errno));
526                         return false;
527                 }
528 #endif
529         return true;
530 }
531
532 #ifdef HAVE_MINGW
533 # define setpriority(level) !SetPriorityClass(GetCurrentProcess(), (level))
534 #else
535 # define NORMAL_PRIORITY_CLASS 0
536 # define BELOW_NORMAL_PRIORITY_CLASS 10
537 # define HIGH_PRIORITY_CLASS -10
538 # define setpriority(level) (setpriority(PRIO_PROCESS, 0, (level)))
539 #endif
540
541 int main(int argc, char **argv) {
542         program_name = argv[0];
543
544         if(!parse_options(argc, argv))
545                 return 1;
546         
547         make_names();
548
549         if(show_version) {
550                 printf("%s version %s (built %s %s, protocol %d)\n", PACKAGE,
551                            VERSION, __DATE__, __TIME__, PROT_CURRENT);
552                 printf("Copyright (C) 1998-2013 Ivo Timmermans, Guus Sliepen and others.\n"
553                                 "See the AUTHORS file for a complete list.\n\n"
554                                 "tinc comes with ABSOLUTELY NO WARRANTY.  This is free software,\n"
555                                 "and you are welcome to redistribute it under certain conditions;\n"
556                                 "see the file COPYING for details.\n");
557
558                 return 0;
559         }
560
561         if(show_help) {
562                 usage(false);
563                 return 0;
564         }
565
566         if(kill_tincd)
567                 return !kill_other(kill_tincd);
568
569         openlogger("tinc", use_logfile?LOGMODE_FILE:LOGMODE_STDERR);
570
571         g_argv = argv;
572
573         if(getenv("LISTEN_PID") && atoi(getenv("LISTEN_PID")) == getpid())
574                 do_detach = false;
575 #ifdef HAVE_UNSETENV
576         unsetenv("LISTEN_PID");
577 #endif
578
579         init_configuration(&config_tree);
580
581         /* Slllluuuuuuurrrrp! */
582
583         RAND_load_file("/dev/urandom", 1024);
584
585         ENGINE_load_builtin_engines();
586         ENGINE_register_all_complete();
587
588         OpenSSL_add_all_algorithms();
589
590         if(generate_keys) {
591                 read_server_config();
592                 return !keygen(generate_keys);
593         }
594
595         if(!read_server_config())
596                 return 1;
597
598 #ifdef HAVE_LZO
599         if(lzo_init() != LZO_E_OK) {
600                 logger(LOG_ERR, "Error initializing LZO compressor!");
601                 return 1;
602         }
603 #endif
604
605 #ifdef HAVE_MINGW
606         if(WSAStartup(MAKEWORD(2, 2), &wsa_state)) {
607                 logger(LOG_ERR, "System call `%s' failed: %s", "WSAStartup", winerror(GetLastError()));
608                 return 1;
609         }
610
611         if(!do_detach || !init_service())
612                 return main2(argc, argv);
613         else
614                 return 1;
615 }
616
617 int main2(int argc, char **argv) {
618         InitializeCriticalSection(&mutex);
619         EnterCriticalSection(&mutex);
620 #endif
621         char *priority = NULL;
622
623         if(!detach())
624                 return 1;
625
626 #ifdef HAVE_MLOCKALL
627         /* Lock all pages into memory if requested.
628          * This has to be done after daemon()/fork() so it works for child.
629          * No need to do that in parent as it's very short-lived. */
630         if(do_mlock && mlockall(MCL_CURRENT | MCL_FUTURE) != 0) {
631                 logger(LOG_ERR, "System call `%s' failed: %s", "mlockall",
632                    strerror(errno));
633                 return 1;
634         }
635 #endif
636
637         /* Setup sockets and open device. */
638
639         if(!setup_network())
640                 goto end;
641
642         /* Initiate all outgoing connections. */
643
644         try_outgoing_connections();
645
646         /* Change process priority */
647
648         if(get_config_string(lookup_config(config_tree, "ProcessPriority"), &priority)) {
649                 if(!strcasecmp(priority, "Normal")) {
650                         if (setpriority(NORMAL_PRIORITY_CLASS) != 0) {
651                                 logger(LOG_ERR, "System call `%s' failed: %s",
652                                        "setpriority", strerror(errno));
653                                 goto end;
654                         }
655                 } else if(!strcasecmp(priority, "Low")) {
656                         if (setpriority(BELOW_NORMAL_PRIORITY_CLASS) != 0) {
657                                        logger(LOG_ERR, "System call `%s' failed: %s",
658                                        "setpriority", strerror(errno));
659                                 goto end;
660                         }
661                 } else if(!strcasecmp(priority, "High")) {
662                         if (setpriority(HIGH_PRIORITY_CLASS) != 0) {
663                                 logger(LOG_ERR, "System call `%s' failed: %s",
664                                        "setpriority", strerror(errno));
665                                 goto end;
666                         }
667                 } else {
668                         logger(LOG_ERR, "Invalid priority `%s`!", priority);
669                         goto end;
670                 }
671         }
672
673         /* drop privileges */
674         if (!drop_privs())
675                 goto end;
676
677         /* Start main loop. It only exits when tinc is killed. */
678
679         status = main_loop();
680
681         /* Shutdown properly. */
682
683         ifdebug(CONNECTIONS)
684                 devops.dump_stats();
685
686         close_network_connections();
687
688 end:
689         logger(LOG_NOTICE, "Terminating");
690
691 #ifndef HAVE_MINGW
692         remove_pid(pidfilename);
693 #endif
694
695         free(priority);
696
697         EVP_cleanup();
698         ENGINE_cleanup();
699         CRYPTO_cleanup_all_ex_data();
700         ERR_remove_state(0);
701         ERR_free_strings();
702
703         exit_configuration(&config_tree);
704         list_free(cmdline_conf);
705         free_names();
706
707         return status;
708 }