www.tinc-vpn.org Git - tinc/blob - 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_LZO
  33 #include LZO1X_H
  34 #endif
  35
  36 #ifdef HAVE_LZ4
  37 #include <lz4.h>
  38 #endif
  39
  40 #ifndef HAVE_WINDOWS
  41 #include <pwd.h>
  42 #include <grp.h>
  43 #include <time.h>
  44 #endif
  45
  46 #include "conf.h"
  47 #include "crypto.h"
  48 #include "event.h"
  49 #include "logger.h"
  50 #include "names.h"
  51 #include "net.h"
  52 #include "process.h"
  53 #include "protocol.h"
  54 #include "utils.h"
  55 #include "xalloc.h"
  56 #include "version.h"
  57
  58 /* If nonzero, display usage information and exit. */
  59 static bool show_help = false;
  60
  61 /* If nonzero, print the version on standard output and exit.  */
  62 static bool show_version = false;
  63
  64 #ifdef HAVE_MLOCKALL
  65 /* If nonzero, disable swapping for this process. */
  66 static bool do_mlock = false;
  67 #endif
  68
  69 #ifndef HAVE_WINDOWS
  70 /* If nonzero, chroot to netdir after startup. */
  71 static bool do_chroot = false;
  72
  73 /* If !NULL, do setuid to given user after startup */
  74 static const char *switchuser = NULL;
  75 #endif
  76
  77 char **g_argv;                  /* a copy of the cmdline arguments */
  78
  79 static int status = 1;
  80
  81 static struct option const long_options[] = {
  82         {"config", required_argument, NULL, 'c'},
  83         {"net", required_argument, NULL, 'n'},
  84         {"help", no_argument, NULL, 1},
  85         {"version", no_argument, NULL, 2},
  86         {"no-detach", no_argument, NULL, 'D'},
  87         {"debug", optional_argument, NULL, 'd'},
  88         {"bypass-security", no_argument, NULL, 3},
  89         {"mlock", no_argument, NULL, 'L'},
  90         {"chroot", no_argument, NULL, 'R'},
  91         {"user", required_argument, NULL, 'U'},
  92         {"logfile", optional_argument, NULL, 4},
  93         {"syslog", no_argument, NULL, 's'},
  94         {"pidfile", required_argument, NULL, 5},
  95         {"option", required_argument, NULL, 'o'},
  96         {NULL, 0, NULL, 0}
  97 };
  98
  99 #ifdef HAVE_WINDOWS
 100 static struct WSAData wsa_state;
 101 int main2(int argc, char **argv);
 102 #endif
 103
 104 static void usage(bool status) {
 105         if(status)
 106                 fprintf(stderr, "Try `%s --help\' for more information.\n",
 107                         program_name);
 108         else {
 109                 static const char *message =
 110                         "Usage: %s [option]...\n"
 111                         "\n"
 112                         "  -c, --config=DIR              Read configuration options from DIR.\n"
 113                         "  -D, --no-detach               Don't fork and detach.\n"
 114                         "  -d, --debug[=LEVEL]           Increase debug level or set it to LEVEL.\n"
 115                         "  -n, --net=NETNAME             Connect to net NETNAME.\n"
 116 #ifdef HAVE_MLOCKALL
 117                         "  -L, --mlock                   Lock tinc into main memory.\n"
 118 #endif
 119                         "      --logfile[=FILENAME]      Write log entries to a logfile.\n"
 120                         "  -s  --syslog                  Use syslog instead of stderr with --no-detach.\n"
 121                         "      --pidfile=FILENAME        Write PID and control socket cookie to FILENAME.\n"
 122                         "      --bypass-security         Disables meta protocol security, for debugging.\n"
 123                         "  -o, --option[HOST.]KEY=VALUE  Set global/host configuration value.\n"
 124 #ifndef HAVE_WINDOWS
 125                         "  -R, --chroot                  chroot to NET dir at startup.\n"
 126                         "  -U, --user=USER               setuid to given USER at startup.\n"
 127 #endif
 128                         "      --help                    Display this help and exit.\n"
 129                         "      --version                 Output version information and exit.\n"
 130                         "\n"
 131                         "Report bugs to tinc@tinc-vpn.org.\n";
 132
 133                 printf(message, program_name);
 134         }
 135 }
 136
 137 static bool parse_options(int argc, char **argv) {
 138         config_t *cfg;
 139         int r;
 140         int option_index = 0;
 141         int lineno = 0;
 142
 143         while((r = getopt_long(argc, argv, "c:DLd::n:so:RU:", long_options, &option_index)) != EOF) {
 144                 switch(r) {
 145                 case 0:   /* long option */
 146                         break;
 147
 148                 case 'c': /* config file */
 149                         free(confbase);
 150                         confbase = xstrdup(optarg);
 151                         break;
 152
 153                 case 'D': /* no detach */
 154                         do_detach = false;
 155                         break;
 156
 157                 case 'L': /* no detach */
 158 #ifndef HAVE_MLOCKALL
 159                         logger(DEBUG_ALWAYS, LOG_ERR, "The %s option is not supported on this platform.", argv[optind - 1]);
 160                         goto exit_fail;
 161 #else
 162                         do_mlock = true;
 163                         break;
 164 #endif
 165
 166                 case 'd': /* increase debug level */
 167                         if(!optarg && optind < argc && *argv[optind] != '-') {
 168                                 optarg = argv[optind++];
 169                         }
 170
 171                         if(optarg) {
 172                                 debug_level = atoi(optarg);
 173                         } else {
 174                                 debug_level++;
 175                         }
 176
 177                         break;
 178
 179                 case 'n': /* net name given */
 180                         free(netname);
 181                         netname = xstrdup(optarg);
 182                         break;
 183
 184                 case 's': /* syslog */
 185                         use_logfile = false;
 186                         use_syslog = true;
 187                         break;
 188
 189                 case 'o': /* option */
 190                         cfg = parse_config_line(optarg, NULL, ++lineno);
 191
 192                         if(!cfg) {
 193                                 goto exit_fail;
 194                         }
 195
 196                         list_insert_tail(&cmdline_conf, cfg);
 197                         break;
 198
 199 #ifdef HAVE_WINDOWS
 200
 201                 case 'R':
 202                 case 'U':
 203                         logger(DEBUG_ALWAYS, LOG_ERR, "The %s option is not supported on this platform.", argv[optind - 1]);
 204                         goto exit_fail;
 205 #else
 206
 207                 case 'R': /* chroot to NETNAME dir */
 208                         do_chroot = true;
 209                         break;
 210
 211                 case 'U': /* setuid to USER */
 212                         switchuser = optarg;
 213                         break;
 214 #endif
 215
 216                 case 1:   /* show help */
 217                         show_help = true;
 218                         break;
 219
 220                 case 2:   /* show version */
 221                         show_version = true;
 222                         break;
 223
 224                 case 3:   /* bypass security */
 225                         bypass_security = true;
 226                         break;
 227
 228                 case 4:   /* write log entries to a file */
 229                         use_syslog = false;
 230                         use_logfile = true;
 231
 232                         if(!optarg && optind < argc && *argv[optind] != '-') {
 233                                 optarg = argv[optind++];
 234                         }
 235
 236                         if(optarg) {
 237                                 free(logfilename);
 238                                 logfilename = xstrdup(optarg);
 239                         }
 240
 241                         break;
 242
 243                 case 5:   /* open control socket here */
 244                         free(pidfilename);
 245                         pidfilename = xstrdup(optarg);
 246                         break;
 247
 248                 case '?': /* wrong options */
 249                         usage(true);
 250                         goto exit_fail;
 251
 252                 default:
 253                         break;
 254                 }
 255         }
 256
 257         if(optind < argc) {
 258                 fprintf(stderr, "%s: unrecognized argument '%s'\n", argv[0], argv[optind]);
 259                 usage(true);
 260                 goto exit_fail;
 261         }
 262
 263         if(!netname && (netname = getenv("NETNAME"))) {
 264                 netname = xstrdup(netname);
 265         }
 266
 267         /* netname "." is special: a "top-level name" */
 268
 269         if(netname && (!*netname || !strcmp(netname, "."))) {
 270                 free(netname);
 271                 netname = NULL;
 272         }
 273
 274         if(netname && !check_netname(netname, false)) {
 275                 fprintf(stderr, "Invalid character in netname!\n");
 276                 goto exit_fail;
 277         }
 278
 279         if(netname && !check_netname(netname, true)) {
 280                 fprintf(stderr, "Warning: unsafe character in netname!\n");
 281         }
 282
 283         return true;
 284
 285 exit_fail:
 286         free_names();
 287         list_empty_list(&cmdline_conf);
 288         return false;
 289 }
 290
 291 static bool drop_privs(void) {
 292 #ifndef HAVE_WINDOWS
 293         uid_t uid = 0;
 294
 295         if(switchuser) {
 296                 struct passwd *pw = getpwnam(switchuser);
 297
 298                 if(!pw) {
 299                         logger(DEBUG_ALWAYS, LOG_ERR, "unknown user `%s'", switchuser);
 300                         return false;
 301                 }
 302
 303                 uid = pw->pw_uid;
 304
 305                 // The second parameter to initgroups on macOS requires int,
 306                 // but __gid_t is unsigned int. There's not much we can do here.
 307                 if(initgroups(switchuser, pw->pw_gid) != 0 || // NOLINT(bugprone-narrowing-conversions)
 308                                 setgid(pw->pw_gid) != 0) {
 309                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
 310                                "initgroups", strerror(errno));
 311                         return false;
 312                 }
 313
 314 #ifndef __ANDROID__
 315 // Not supported in android NDK
 316                 endgrent();
 317                 endpwent();
 318 #endif
 319         }
 320
 321         if(do_chroot) {
 322                 tzset();        /* for proper timestamps in logs */
 323
 324                 if(chroot(confbase) != 0 || chdir("/") != 0) {
 325                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
 326                                "chroot", strerror(errno));
 327                         return false;
 328                 }
 329
 330                 free(confbase);
 331                 confbase = xstrdup("");
 332         }
 333
 334         if(switchuser)
 335                 if(setuid(uid) != 0) {
 336                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
 337                                "setuid", strerror(errno));
 338                         return false;
 339                 }
 340
 341 #endif
 342         return true;
 343 }
 344
 345 #ifdef HAVE_WINDOWS
 346 # define setpriority(level) !SetPriorityClass(GetCurrentProcess(), (level))
 347
 348 static void stop_handler(void *data, int flags) {
 349         (void)data;
 350         (void)flags;
 351
 352         event_exit();
 353 }
 354
 355 static BOOL WINAPI console_ctrl_handler(DWORD type) {
 356         (void)type;
 357
 358         logger(DEBUG_ALWAYS, LOG_NOTICE, "Got console shutdown request");
 359
 360         if(WSASetEvent(stop_io.event) == FALSE) {
 361                 abort();
 362         }
 363
 364         return TRUE;
 365 }
 366 #else
 367 # define NORMAL_PRIORITY_CLASS 0
 368 # define BELOW_NORMAL_PRIORITY_CLASS 10
 369 # define HIGH_PRIORITY_CLASS -10
 370 # define setpriority(level) (setpriority(PRIO_PROCESS, 0, (level)))
 371 #endif
 372
 373 static void cleanup(void) {
 374         splay_empty_tree(&config_tree);
 375         list_empty_list(&cmdline_conf);
 376         free_names();
 377 }
 378
 379 int main(int argc, char **argv) {
 380         program_name = argv[0];
 381
 382         if(!parse_options(argc, argv)) {
 383                 return 1;
 384         }
 385
 386         if(show_version) {
 387                 static const char *message =
 388                         "%s version %s (built %s %s, protocol %d.%d)\n"
 389                         "Features:"
 390 #ifdef HAVE_OPENSSL
 391                         " openssl"
 392 #endif
 393 #ifdef HAVE_LIBGCRYPT
 394                         " libgcrypt"
 395 #endif
 396 #ifdef HAVE_LZO
 397                         " comp_lzo"
 398 #endif
 399 #ifdef HAVE_ZLIB
 400                         " comp_zlib"
 401 #endif
 402 #ifdef HAVE_LZ4
 403                         " comp_lz4"
 404 #endif
 405 #ifndef DISABLE_LEGACY
 406                         " legacy_protocol"
 407 #endif
 408 #ifdef ENABLE_JUMBOGRAMS
 409                         " jumbograms"
 410 #endif
 411 #ifdef ENABLE_TUNEMU
 412                         " tunemu"
 413 #endif
 414 #ifdef HAVE_MINIUPNPC
 415                         " miniupnpc"
 416 #endif
 417 #ifdef ENABLE_UML
 418                         " uml"
 419 #endif
 420 #ifdef ENABLE_VDE
 421                         " vde"
 422 #endif
 423                         "\n\n"
 424                         "Copyright (C) 1998-2021 Ivo Timmermans, Guus Sliepen and others.\n"
 425                         "See the AUTHORS file for a complete list.\n"
 426                         "\n"
 427                         "tinc comes with ABSOLUTELY NO WARRANTY.  This is free software,\n"
 428                         "and you are welcome to redistribute it under certain conditions;\n"
 429                         "see the file COPYING for details.\n";
 430
 431                 printf(message, PACKAGE, BUILD_VERSION, BUILD_DATE, BUILD_TIME, PROT_MAJOR, PROT_MINOR);
 432                 return 0;
 433         }
 434
 435         if(show_help) {
 436                 usage(false);
 437                 return 0;
 438         }
 439
 440         make_names(true);
 441         atexit(cleanup);
 442
 443         if(chdir(confbase) == -1) {
 444                 logger(DEBUG_ALWAYS, LOG_ERR, "Could not change to configuration directory: %s", strerror(errno));
 445                 return 1;
 446         }
 447
 448 #ifdef HAVE_WINDOWS
 449
 450         if(WSAStartup(MAKEWORD(2, 2), &wsa_state)) {
 451                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "WSAStartup", winerror(GetLastError()));
 452                 return 1;
 453         }
 454
 455 #else
 456         // Check if we got an umbilical fd from the process that started us
 457         char *umbstr = getenv("TINC_UMBILICAL");
 458
 459         if(umbstr) {
 460                 umbilical = atoi(umbstr);
 461
 462                 if(fcntl(umbilical, F_GETFL) < 0) {
 463                         umbilical = 0;
 464                 }
 465
 466 #ifdef FD_CLOEXEC
 467
 468                 if(umbilical) {
 469                         fcntl(umbilical, F_SETFD, FD_CLOEXEC);
 470                 }
 471
 472 #endif
 473         }
 474
 475 #endif
 476
 477         openlogger("tinc", use_logfile ? LOGMODE_FILE : LOGMODE_STDERR);
 478
 479         g_argv = argv;
 480
 481         if(getenv("LISTEN_PID") && atoi(getenv("LISTEN_PID")) == getpid()) {
 482                 do_detach = false;
 483         }
 484
 485 #ifdef HAVE_UNSETENV
 486         unsetenv("LISTEN_PID");
 487 #endif
 488
 489         gettimeofday(&now, NULL);
 490         crypto_init();
 491         prng_init();
 492
 493         if(!read_server_config(&config_tree)) {
 494                 return 1;
 495         }
 496
 497         if(debug_level == DEBUG_NOTHING) {
 498                 int level = 0;
 499
 500                 if(get_config_int(lookup_config(&config_tree, "LogLevel"), &level)) {
 501                         debug_level = level;
 502                 }
 503         }
 504
 505 #ifdef HAVE_LZO
 506
 507         if(lzo_init() != LZO_E_OK) {
 508                 logger(DEBUG_ALWAYS, LOG_ERR, "Error initializing LZO compressor!");
 509                 return 1;
 510         }
 511
 512 #endif
 513
 514 #ifdef HAVE_WINDOWS
 515         io_add_event(&stop_io, stop_handler, NULL, WSACreateEvent());
 516
 517         if(stop_io.event == FALSE) {
 518                 abort();
 519         }
 520
 521         int result;
 522
 523         if(!do_detach || !init_service()) {
 524                 SetConsoleCtrlHandler(console_ctrl_handler, TRUE);
 525                 result = main2(argc, argv);
 526         } else {
 527                 result = 1;
 528         }
 529
 530         if(WSACloseEvent(stop_io.event) == FALSE) {
 531                 abort();
 532         }
 533
 534         io_del(&stop_io);
 535         return result;
 536 }
 537
 538 int main2(int argc, char **argv) {
 539         (void)argc;
 540         (void)argv;
 541 #endif
 542         char *priority = NULL;
 543
 544         if(!detach()) {
 545                 return 1;
 546         }
 547
 548 #ifdef HAVE_MLOCKALL
 549
 550         /* Lock all pages into memory if requested.
 551          * This has to be done after daemon()/fork() so it works for child.
 552          * No need to do that in parent as it's very short-lived. */
 553         if(do_mlock && mlockall(MCL_CURRENT | MCL_FUTURE) != 0) {
 554                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "mlockall",
 555                        strerror(errno));
 556                 return 1;
 557         }
 558
 559 #endif
 560
 561         /* Setup sockets and open device. */
 562
 563         if(!setup_network()) {
 564                 goto end;
 565         }
 566
 567         /* Change process priority */
 568
 569         if(get_config_string(lookup_config(&config_tree, "ProcessPriority"), &priority)) {
 570                 if(!strcasecmp(priority, "Normal")) {
 571                         if(setpriority(NORMAL_PRIORITY_CLASS) != 0) {
 572                                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setpriority", strerror(errno));
 573                                 goto end;
 574                         }
 575                 } else if(!strcasecmp(priority, "Low")) {
 576                         if(setpriority(BELOW_NORMAL_PRIORITY_CLASS) != 0) {
 577                                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setpriority", strerror(errno));
 578                                 goto end;
 579                         }
 580                 } else if(!strcasecmp(priority, "High")) {
 581                         if(setpriority(HIGH_PRIORITY_CLASS) != 0) {
 582                                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setpriority", strerror(errno));
 583                                 goto end;
 584                         }
 585                 } else {
 586                         logger(DEBUG_ALWAYS, LOG_ERR, "Invalid priority `%s`!", priority);
 587                         goto end;
 588                 }
 589         }
 590
 591         /* drop privileges */
 592         if(!drop_privs()) {
 593                 goto end;
 594         }
 595
 596         /* Start main loop. It only exits when tinc is killed. */
 597
 598         logger(DEBUG_ALWAYS, LOG_NOTICE, "Ready");
 599
 600         if(umbilical) { // snip!
 601                 if(write(umbilical, "", 1) != 1) {
 602                         // Pipe full or broken, nothing we can do about it.
 603                 }
 604
 605                 close(umbilical);
 606                 umbilical = 0;
 607         }
 608
 609         try_outgoing_connections();
 610
 611         status = main_loop();
 612
 613         /* Shutdown properly. */
 614
 615 end:
 616         close_network_connections();
 617
 618         logger(DEBUG_ALWAYS, LOG_NOTICE, "Terminating");
 619
 620         free(priority);
 621
 622         crypto_exit();
 623
 624         return status;
 625 }