git.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 #include "random.h"
  58
  59 /* If nonzero, display usage information and exit. */
  60 static bool show_help = false;
  61
  62 /* If nonzero, print the version on standard output and exit.  */
  63 static bool show_version = false;
  64
  65 #ifdef HAVE_MLOCKALL
  66 /* If nonzero, disable swapping for this process. */
  67 static bool do_mlock = false;
  68 #endif
  69
  70 #ifndef HAVE_WINDOWS
  71 /* If nonzero, chroot to netdir after startup. */
  72 static bool do_chroot = false;
  73
  74 /* If !NULL, do setuid to given user after startup */
  75 static const char *switchuser = NULL;
  76 #endif
  77
  78 char **g_argv;                  /* a copy of the cmdline arguments */
  79
  80 static int status = 1;
  81
  82 typedef enum option_t {
  83         OPT_BAD_OPTION  = '?',
  84         OPT_LONG_OPTION =  0,
  85
  86         // Short options
  87         OPT_CONFIG_FILE = 'c',
  88         OPT_NETNAME     = 'n',
  89         OPT_NO_DETACH   = 'D',
  90         OPT_DEBUG       = 'd',
  91         OPT_MLOCK       = 'L',
  92         OPT_CHROOT      = 'R',
  93         OPT_CHANGE_USER = 'U',
  94         OPT_SYSLOG      = 's',
  95         OPT_OPTION      = 'o',
  96
  97         // Long options
  98         OPT_HELP        = 255,
  99         OPT_VERSION,
 100         OPT_NO_SECURITY,
 101         OPT_LOGFILE,
 102         OPT_PIDFILE,
 103 } option_t;
 104
 105 static struct option const long_options[] = {
 106         {"config",          required_argument, NULL, OPT_CONFIG_FILE},
 107         {"net",             required_argument, NULL, OPT_NETNAME},
 108         {"no-detach",       no_argument,       NULL, OPT_NO_DETACH},
 109         {"debug",           optional_argument, NULL, OPT_DEBUG},
 110         {"mlock",           no_argument,       NULL, OPT_MLOCK},
 111         {"chroot",          no_argument,       NULL, OPT_CHROOT},
 112         {"user",            required_argument, NULL, OPT_CHANGE_USER},
 113         {"syslog",          no_argument,       NULL, OPT_SYSLOG},
 114         {"option",          required_argument, NULL, OPT_OPTION},
 115         {"help",            no_argument,       NULL, OPT_HELP},
 116         {"version",         no_argument,       NULL, OPT_VERSION},
 117         {"bypass-security", no_argument,       NULL, OPT_NO_SECURITY},
 118         {"logfile",         optional_argument, NULL, OPT_LOGFILE},
 119         {"pidfile",         required_argument, NULL, OPT_PIDFILE},
 120         {NULL,              0,                 NULL, 0},
 121 };
 122
 123 #ifdef HAVE_WINDOWS
 124 static struct WSAData wsa_state;
 125 int main2(int argc, char **argv);
 126 #endif
 127
 128 static void usage(bool status) {
 129         if(status)
 130                 fprintf(stderr, "Try `%s --help\' for more information.\n",
 131                         program_name);
 132         else {
 133                 static const char *message =
 134                         "Usage: %s [option]...\n"
 135                         "\n"
 136                         "  -c, --config=DIR              Read configuration options from DIR.\n"
 137                         "  -D, --no-detach               Don't fork and detach.\n"
 138                         "  -d, --debug[=LEVEL]           Increase debug level or set it to LEVEL.\n"
 139                         "  -n, --net=NETNAME             Connect to net NETNAME.\n"
 140 #ifdef HAVE_MLOCKALL
 141                         "  -L, --mlock                   Lock tinc into main memory.\n"
 142 #endif
 143                         "      --logfile[=FILENAME]      Write log entries to a logfile.\n"
 144                         "  -s  --syslog                  Use syslog instead of stderr with --no-detach.\n"
 145                         "      --pidfile=FILENAME        Write PID and control socket cookie to FILENAME.\n"
 146                         "      --bypass-security         Disables meta protocol security, for debugging.\n"
 147                         "  -o, --option[HOST.]KEY=VALUE  Set global/host configuration value.\n"
 148 #ifndef HAVE_WINDOWS
 149                         "  -R, --chroot                  chroot to NET dir at startup.\n"
 150                         "  -U, --user=USER               setuid to given USER at startup.\n"
 151 #endif
 152                         "      --help                    Display this help and exit.\n"
 153                         "      --version                 Output version information and exit.\n"
 154                         "\n"
 155                         "Report bugs to tinc@tinc-vpn.org.\n";
 156
 157                 printf(message, program_name);
 158         }
 159 }
 160
 161 static bool parse_options(int argc, char **argv) {
 162         config_t *cfg;
 163         int r;
 164         int option_index = 0;
 165         int lineno = 0;
 166
 167         while((r = getopt_long(argc, argv, "c:DLd::n:so:RU:", long_options, &option_index)) != EOF) {
 168                 switch((option_t) r) {
 169                 case OPT_LONG_OPTION:
 170                         break;
 171
 172                 case OPT_BAD_OPTION:
 173                         usage(true);
 174                         goto exit_fail;
 175
 176                 case OPT_CONFIG_FILE:
 177                         free(confbase);
 178                         confbase = xstrdup(optarg);
 179                         break;
 180
 181                 case OPT_NO_DETACH:
 182                         do_detach = false;
 183                         break;
 184
 185                 case OPT_MLOCK: /* lock tincd into RAM */
 186 #ifndef HAVE_MLOCKALL
 187                         logger(DEBUG_ALWAYS, LOG_ERR, "The %s option is not supported on this platform.", argv[optind - 1]);
 188                         goto exit_fail;
 189 #else
 190                         do_mlock = true;
 191                         break;
 192 #endif
 193
 194                 case OPT_DEBUG: /* increase debug level */
 195                         if(!optarg && optind < argc && *argv[optind] != '-') {
 196                                 optarg = argv[optind++];
 197                         }
 198
 199                         if(optarg) {
 200                                 debug_level = atoi(optarg);
 201                         } else {
 202                                 debug_level++;
 203                         }
 204
 205                         break;
 206
 207                 case OPT_NETNAME:
 208                         free(netname);
 209                         netname = xstrdup(optarg);
 210                         break;
 211
 212                 case OPT_SYSLOG:
 213                         use_logfile = false;
 214                         use_syslog = true;
 215                         break;
 216
 217                 case OPT_OPTION:
 218                         cfg = parse_config_line(optarg, NULL, ++lineno);
 219
 220                         if(!cfg) {
 221                                 goto exit_fail;
 222                         }
 223
 224                         list_insert_tail(&cmdline_conf, cfg);
 225                         break;
 226
 227 #ifdef HAVE_WINDOWS
 228
 229                 case OPT_CHANGE_USER:
 230                 case OPT_CHROOT:
 231                         logger(DEBUG_ALWAYS, LOG_ERR, "The %s option is not supported on this platform.", argv[optind - 1]);
 232                         goto exit_fail;
 233 #else
 234
 235                 case OPT_CHROOT:
 236                         do_chroot = true;
 237                         break;
 238
 239                 case OPT_CHANGE_USER:
 240                         switchuser = optarg;
 241                         break;
 242 #endif
 243
 244                 case OPT_HELP:
 245                         show_help = true;
 246                         break;
 247
 248                 case OPT_VERSION:
 249                         show_version = true;
 250                         break;
 251
 252                 case OPT_NO_SECURITY:
 253                         bypass_security = true;
 254                         break;
 255
 256                 case OPT_LOGFILE:
 257                         use_syslog = false;
 258                         use_logfile = true;
 259
 260                         if(!optarg && optind < argc && *argv[optind] != '-') {
 261                                 optarg = argv[optind++];
 262                         }
 263
 264                         if(optarg) {
 265                                 free(logfilename);
 266                                 logfilename = xstrdup(optarg);
 267                         }
 268
 269                         break;
 270
 271                 case OPT_PIDFILE:
 272                         free(pidfilename);
 273                         pidfilename = xstrdup(optarg);
 274                         break;
 275
 276                 default:
 277                         break;
 278                 }
 279         }
 280
 281         if(optind < argc) {
 282                 fprintf(stderr, "%s: unrecognized argument '%s'\n", argv[0], argv[optind]);
 283                 usage(true);
 284                 goto exit_fail;
 285         }
 286
 287         if(!netname && (netname = getenv("NETNAME"))) {
 288                 netname = xstrdup(netname);
 289         }
 290
 291         /* netname "." is special: a "top-level name" */
 292
 293         if(netname && (!*netname || !strcmp(netname, "."))) {
 294                 free(netname);
 295                 netname = NULL;
 296         }
 297
 298         if(netname && !check_netname(netname, false)) {
 299                 fprintf(stderr, "Invalid character in netname!\n");
 300                 goto exit_fail;
 301         }
 302
 303         if(netname && !check_netname(netname, true)) {
 304                 fprintf(stderr, "Warning: unsafe character in netname!\n");
 305         }
 306
 307         return true;
 308
 309 exit_fail:
 310         free_names();
 311         list_empty_list(&cmdline_conf);
 312         return false;
 313 }
 314
 315 static bool drop_privs(void) {
 316 #ifndef HAVE_WINDOWS
 317         uid_t uid = 0;
 318
 319         if(switchuser) {
 320                 struct passwd *pw = getpwnam(switchuser);
 321
 322                 if(!pw) {
 323                         logger(DEBUG_ALWAYS, LOG_ERR, "unknown user `%s'", switchuser);
 324                         return false;
 325                 }
 326
 327                 uid = pw->pw_uid;
 328
 329                 // The second parameter to initgroups on macOS requires int,
 330                 // but __gid_t is unsigned int. There's not much we can do here.
 331                 if(initgroups(switchuser, pw->pw_gid) != 0 || // NOLINT(bugprone-narrowing-conversions)
 332                                 setgid(pw->pw_gid) != 0) {
 333                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
 334                                "initgroups", strerror(errno));
 335                         return false;
 336                 }
 337
 338 #ifndef __ANDROID__
 339 // Not supported in android NDK
 340                 endgrent();
 341                 endpwent();
 342 #endif
 343         }
 344
 345         if(do_chroot) {
 346                 tzset();        /* for proper timestamps in logs */
 347
 348                 if(chroot(confbase) != 0 || chdir("/") != 0) {
 349                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
 350                                "chroot", strerror(errno));
 351                         return false;
 352                 }
 353
 354                 free(confbase);
 355                 confbase = xstrdup("");
 356         }
 357
 358         if(switchuser)
 359                 if(setuid(uid) != 0) {
 360                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
 361                                "setuid", strerror(errno));
 362                         return false;
 363                 }
 364
 365 #endif
 366         return true;
 367 }
 368
 369 #ifdef HAVE_WINDOWS
 370 # define setpriority(level) !SetPriorityClass(GetCurrentProcess(), (level))
 371
 372 static void stop_handler(void *data, int flags) {
 373         (void)data;
 374         (void)flags;
 375
 376         event_exit();
 377 }
 378
 379 static BOOL WINAPI console_ctrl_handler(DWORD type) {
 380         (void)type;
 381
 382         logger(DEBUG_ALWAYS, LOG_NOTICE, "Got console shutdown request");
 383
 384         if(WSASetEvent(stop_io.event) == FALSE) {
 385                 abort();
 386         }
 387
 388         return TRUE;
 389 }
 390 #else
 391 # define NORMAL_PRIORITY_CLASS 0
 392 # define BELOW_NORMAL_PRIORITY_CLASS 10
 393 # define HIGH_PRIORITY_CLASS -10
 394 # define setpriority(level) (setpriority(PRIO_PROCESS, 0, (level)))
 395 #endif
 396
 397 static void cleanup(void) {
 398         splay_empty_tree(&config_tree);
 399         list_empty_list(&cmdline_conf);
 400         free_names();
 401 }
 402
 403 int main(int argc, char **argv) {
 404         program_name = argv[0];
 405
 406         if(!parse_options(argc, argv)) {
 407                 return 1;
 408         }
 409
 410         if(show_version) {
 411                 static const char *message =
 412                         "%s version %s (built %s %s, protocol %d.%d)\n"
 413                         "Features:"
 414 #ifdef HAVE_OPENSSL
 415                         " openssl"
 416 #endif
 417 #ifdef HAVE_LIBGCRYPT
 418                         " libgcrypt"
 419 #endif
 420 #ifdef HAVE_LZO
 421                         " comp_lzo"
 422 #endif
 423 #ifdef HAVE_ZLIB
 424                         " comp_zlib"
 425 #endif
 426 #ifdef HAVE_LZ4
 427                         " comp_lz4"
 428 #endif
 429 #ifndef DISABLE_LEGACY
 430                         " legacy_protocol"
 431 #endif
 432 #ifdef ENABLE_JUMBOGRAMS
 433                         " jumbograms"
 434 #endif
 435 #ifdef ENABLE_TUNEMU
 436                         " tunemu"
 437 #endif
 438 #ifdef HAVE_MINIUPNPC
 439                         " miniupnpc"
 440 #endif
 441 #ifdef ENABLE_UML
 442                         " uml"
 443 #endif
 444 #ifdef ENABLE_VDE
 445                         " vde"
 446 #endif
 447                         "\n\n"
 448                         "Copyright (C) 1998-2021 Ivo Timmermans, Guus Sliepen and others.\n"
 449                         "See the AUTHORS file for a complete list.\n"
 450                         "\n"
 451                         "tinc comes with ABSOLUTELY NO WARRANTY.  This is free software,\n"
 452                         "and you are welcome to redistribute it under certain conditions;\n"
 453                         "see the file COPYING for details.\n";
 454
 455                 printf(message, PACKAGE, BUILD_VERSION, BUILD_DATE, BUILD_TIME, PROT_MAJOR, PROT_MINOR);
 456                 return 0;
 457         }
 458
 459         if(show_help) {
 460                 usage(false);
 461                 return 0;
 462         }
 463
 464         make_names(true);
 465         atexit(cleanup);
 466
 467         if(chdir(confbase) == -1) {
 468                 logger(DEBUG_ALWAYS, LOG_ERR, "Could not change to configuration directory: %s", strerror(errno));
 469                 return 1;
 470         }
 471
 472 #ifdef HAVE_WINDOWS
 473
 474         if(WSAStartup(MAKEWORD(2, 2), &wsa_state)) {
 475                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "WSAStartup", winerror(GetLastError()));
 476                 return 1;
 477         }
 478
 479 #else
 480         // Check if we got an umbilical fd from the process that started us
 481         char *umbstr = getenv("TINC_UMBILICAL");
 482
 483         if(umbstr) {
 484                 int colorize = 0;
 485                 sscanf(umbstr, "%d %d", &umbilical, &colorize);
 486                 umbilical_colorize = colorize;
 487
 488                 if(fcntl(umbilical, F_GETFL) < 0) {
 489                         umbilical = 0;
 490                 }
 491
 492 #ifdef FD_CLOEXEC
 493
 494                 if(umbilical) {
 495                         fcntl(umbilical, F_SETFD, FD_CLOEXEC);
 496                 }
 497
 498 #endif
 499         }
 500
 501 #endif
 502
 503         openlogger("tinc", use_logfile ? LOGMODE_FILE : LOGMODE_STDERR);
 504
 505         g_argv = argv;
 506
 507         if(getenv("LISTEN_PID") && atoi(getenv("LISTEN_PID")) == getpid()) {
 508                 do_detach = false;
 509         }
 510
 511 #ifdef HAVE_UNSETENV
 512         unsetenv("LISTEN_PID");
 513 #endif
 514
 515         gettimeofday(&now, NULL);
 516         random_init();
 517         crypto_init();
 518         prng_init();
 519
 520         if(!read_server_config(&config_tree)) {
 521                 return 1;
 522         }
 523
 524         if(debug_level == DEBUG_NOTHING) {
 525                 int level = 0;
 526
 527                 if(get_config_int(lookup_config(&config_tree, "LogLevel"), &level)) {
 528                         debug_level = level;
 529                 }
 530         }
 531
 532 #ifdef HAVE_LZO
 533
 534         if(lzo_init() != LZO_E_OK) {
 535                 logger(DEBUG_ALWAYS, LOG_ERR, "Error initializing LZO compressor!");
 536                 return 1;
 537         }
 538
 539 #endif
 540
 541 #ifdef HAVE_WINDOWS
 542         io_add_event(&stop_io, stop_handler, NULL, WSACreateEvent());
 543
 544         if(stop_io.event == FALSE) {
 545                 abort();
 546         }
 547
 548         int result;
 549
 550         if(!do_detach || !init_service()) {
 551                 SetConsoleCtrlHandler(console_ctrl_handler, TRUE);
 552                 result = main2(argc, argv);
 553         } else {
 554                 result = 1;
 555         }
 556
 557         if(WSACloseEvent(stop_io.event) == FALSE) {
 558                 abort();
 559         }
 560
 561         io_del(&stop_io);
 562         return result;
 563 }
 564
 565 int main2(int argc, char **argv) {
 566         (void)argc;
 567         (void)argv;
 568 #endif
 569         char *priority = NULL;
 570
 571         if(!detach()) {
 572                 return 1;
 573         }
 574
 575 #ifdef HAVE_MLOCKALL
 576
 577         /* Lock all pages into memory if requested.
 578          * This has to be done after daemon()/fork() so it works for child.
 579          * No need to do that in parent as it's very short-lived. */
 580         if(do_mlock && mlockall(MCL_CURRENT | MCL_FUTURE) != 0) {
 581                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "mlockall",
 582                        strerror(errno));
 583                 return 1;
 584         }
 585
 586 #endif
 587
 588         /* Setup sockets and open device. */
 589
 590         if(!setup_network()) {
 591                 goto end;
 592         }
 593
 594         /* Change process priority */
 595
 596         if(get_config_string(lookup_config(&config_tree, "ProcessPriority"), &priority)) {
 597                 if(!strcasecmp(priority, "Normal")) {
 598                         if(setpriority(NORMAL_PRIORITY_CLASS) != 0) {
 599                                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setpriority", strerror(errno));
 600                                 goto end;
 601                         }
 602                 } else if(!strcasecmp(priority, "Low")) {
 603                         if(setpriority(BELOW_NORMAL_PRIORITY_CLASS) != 0) {
 604                                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setpriority", strerror(errno));
 605                                 goto end;
 606                         }
 607                 } else if(!strcasecmp(priority, "High")) {
 608                         if(setpriority(HIGH_PRIORITY_CLASS) != 0) {
 609                                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setpriority", strerror(errno));
 610                                 goto end;
 611                         }
 612                 } else {
 613                         logger(DEBUG_ALWAYS, LOG_ERR, "Invalid priority `%s`!", priority);
 614                         goto end;
 615                 }
 616         }
 617
 618         /* drop privileges */
 619         if(!drop_privs()) {
 620                 goto end;
 621         }
 622
 623         /* Start main loop. It only exits when tinc is killed. */
 624
 625         logger(DEBUG_ALWAYS, LOG_NOTICE, "Ready");
 626
 627         if(umbilical) { // snip!
 628                 if(write(umbilical, "", 1) != 1) {
 629                         // Pipe full or broken, nothing we can do about it.
 630                 }
 631
 632                 close(umbilical);
 633                 umbilical = 0;
 634         }
 635
 636         try_outgoing_connections();
 637
 638         status = main_loop();
 639
 640         /* Shutdown properly. */
 641
 642 end:
 643         close_network_connections();
 644
 645         logger(DEBUG_ALWAYS, LOG_NOTICE, "Terminating");
 646
 647         free(priority);
 648
 649         random_exit();
 650
 651         return status;
 652 }