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 #include "sandbox.h"
  59 #include "watchdog.h"
  60 #include "fs.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 #ifdef HAVE_MLOCKALL
  69 /* If nonzero, disable swapping for this process. */
  70 static bool do_mlock = false;
  71 #endif
  72
  73 #ifndef HAVE_WINDOWS
  74 /* If nonzero, chroot to netdir after startup. */
  75 static bool do_chroot = false;
  76
  77 /* If !NULL, do setuid to given user after startup */
  78 static const char *switchuser = NULL;
  79 #endif
  80
  81 char **g_argv;                  /* a copy of the cmdline arguments */
  82
  83 static int status = 1;
  84
  85 typedef enum option_t {
  86         OPT_BAD_OPTION  = '?',
  87         OPT_LONG_OPTION =  0,
  88
  89         // Short options
  90         OPT_CONFIG_FILE = 'c',
  91         OPT_NETNAME     = 'n',
  92         OPT_NO_DETACH   = 'D',
  93         OPT_DEBUG       = 'd',
  94         OPT_MLOCK       = 'L',
  95         OPT_CHROOT      = 'R',
  96         OPT_CHANGE_USER = 'U',
  97         OPT_SYSLOG      = 's',
  98         OPT_OPTION      = 'o',
  99
 100         // Long options
 101         OPT_HELP        = 255,
 102         OPT_VERSION,
 103         OPT_NO_SECURITY,
 104         OPT_LOGFILE,
 105         OPT_PIDFILE,
 106 } option_t;
 107
 108 static struct option const long_options[] = {
 109         {"config",          required_argument, NULL, OPT_CONFIG_FILE},
 110         {"net",             required_argument, NULL, OPT_NETNAME},
 111         {"no-detach",       no_argument,       NULL, OPT_NO_DETACH},
 112         {"debug",           optional_argument, NULL, OPT_DEBUG},
 113         {"mlock",           no_argument,       NULL, OPT_MLOCK},
 114         {"chroot",          no_argument,       NULL, OPT_CHROOT},
 115         {"user",            required_argument, NULL, OPT_CHANGE_USER},
 116         {"syslog",          no_argument,       NULL, OPT_SYSLOG},
 117         {"option",          required_argument, NULL, OPT_OPTION},
 118         {"help",            no_argument,       NULL, OPT_HELP},
 119         {"version",         no_argument,       NULL, OPT_VERSION},
 120         {"bypass-security", no_argument,       NULL, OPT_NO_SECURITY},
 121         {"logfile",         optional_argument, NULL, OPT_LOGFILE},
 122         {"pidfile",         required_argument, NULL, OPT_PIDFILE},
 123         {NULL,              0,                 NULL, 0},
 124 };
 125
 126 #ifdef HAVE_WINDOWS
 127 static struct WSAData wsa_state;
 128 int main2(int argc, char **argv);
 129 #endif
 130
 131 static void usage(bool status) {
 132         if(status)
 133                 fprintf(stderr, "Try `%s --help\' for more information.\n",
 134                         program_name);
 135         else {
 136                 fprintf(stdout,
 137                         "Usage: %s [option]...\n"
 138                         "\n"
 139                         "  -c, --config=DIR              Read configuration options from DIR.\n"
 140                         "  -D, --no-detach               Don't fork and detach.\n"
 141                         "  -d, --debug[=LEVEL]           Increase debug level or set it to LEVEL.\n"
 142                         "  -n, --net=NETNAME             Connect to net NETNAME.\n"
 143 #ifdef HAVE_MLOCKALL
 144                         "  -L, --mlock                   Lock tinc into main memory.\n"
 145 #endif
 146                         "      --logfile[=FILENAME]      Write log entries to a logfile.\n"
 147                         "  -s  --syslog                  Use syslog instead of stderr with --no-detach.\n"
 148                         "      --pidfile=FILENAME        Write PID and control socket cookie to FILENAME.\n"
 149                         "      --bypass-security         Disables meta protocol security, for debugging.\n"
 150                         "  -o, --option[HOST.]KEY=VALUE  Set global/host configuration value.\n"
 151 #ifndef HAVE_WINDOWS
 152                         "  -R, --chroot                  chroot to NET dir at startup.\n"
 153                         "  -U, --user=USER               setuid to given USER at startup.\n"
 154 #endif
 155                         "      --help                    Display this help and exit.\n"
 156                         "      --version                 Output version information and exit.\n"
 157                         "\n"
 158                         "Report bugs to tinc@tinc-vpn.org.\n",
 159                         program_name);
 160         }
 161 }
 162
 163 // Try to resolve path to absolute, return a copy of the argument if this fails.
 164 static char *get_path_arg(char *arg) {
 165         char *result = absolute_path(arg);
 166
 167         if(!result) {
 168                 result = xstrdup(arg);
 169         }
 170
 171         return result;
 172 }
 173
 174 static bool parse_options(int argc, char **argv) {
 175         config_t *cfg;
 176         int r;
 177         int option_index = 0;
 178         int lineno = 0;
 179
 180         while((r = getopt_long(argc, argv, "c:DLd::n:so:RU:", long_options, &option_index)) != EOF) {
 181                 switch((option_t) r) {
 182                 case OPT_LONG_OPTION:
 183                         break;
 184
 185                 case OPT_BAD_OPTION:
 186                         usage(true);
 187                         goto exit_fail;
 188
 189                 case OPT_CONFIG_FILE:
 190                         assert(optarg);
 191                         free(confbase);
 192                         confbase = get_path_arg(optarg);
 193                         break;
 194
 195                 case OPT_NO_DETACH:
 196                         do_detach = false;
 197                         break;
 198
 199                 case OPT_MLOCK: /* lock tincd into RAM */
 200 #ifndef HAVE_MLOCKALL
 201                         logger(DEBUG_ALWAYS, LOG_ERR, "The %s option is not supported on this platform.", argv[optind - 1]);
 202                         goto exit_fail;
 203 #else
 204                         do_mlock = true;
 205                         break;
 206 #endif
 207
 208                 case OPT_DEBUG: /* increase debug level */
 209                         if(!optarg && optind < argc && *argv[optind] != '-') {
 210                                 optarg = argv[optind++];
 211                         }
 212
 213                         if(optarg) {
 214                                 debug_level = atoi(optarg);
 215                         } else {
 216                                 debug_level++;
 217                         }
 218
 219                         break;
 220
 221                 case OPT_NETNAME:
 222                         assert(optarg);
 223                         free(netname);
 224                         netname = xstrdup(optarg);
 225                         break;
 226
 227                 case OPT_SYSLOG:
 228                         use_logfile = false;
 229                         use_syslog = true;
 230                         break;
 231
 232                 case OPT_OPTION:
 233                         cfg = parse_config_line(optarg, NULL, ++lineno);
 234
 235                         if(!cfg) {
 236                                 goto exit_fail;
 237                         }
 238
 239                         list_insert_tail(&cmdline_conf, cfg);
 240                         break;
 241
 242 #ifdef HAVE_WINDOWS
 243
 244                 case OPT_CHANGE_USER:
 245                 case OPT_CHROOT:
 246                         logger(DEBUG_ALWAYS, LOG_ERR, "The %s option is not supported on this platform.", argv[optind - 1]);
 247                         goto exit_fail;
 248 #else
 249
 250                 case OPT_CHROOT:
 251                         do_chroot = true;
 252                         break;
 253
 254                 case OPT_CHANGE_USER:
 255                         switchuser = optarg;
 256                         break;
 257 #endif
 258
 259                 case OPT_HELP:
 260                         show_help = true;
 261                         break;
 262
 263                 case OPT_VERSION:
 264                         show_version = true;
 265                         break;
 266
 267                 case OPT_NO_SECURITY:
 268                         bypass_security = true;
 269                         break;
 270
 271                 case OPT_LOGFILE:
 272                         use_syslog = false;
 273                         use_logfile = true;
 274
 275                         if(!optarg && optind < argc && *argv[optind] != '-') {
 276                                 optarg = argv[optind++];
 277                         }
 278
 279                         if(optarg) {
 280                                 free(logfilename);
 281                                 logfilename = get_path_arg(optarg);
 282                         }
 283
 284                         break;
 285
 286                 case OPT_PIDFILE:
 287                         assert(optarg);
 288                         free(pidfilename);
 289                         pidfilename = get_path_arg(optarg);
 290                         break;
 291
 292                 default:
 293                         break;
 294                 }
 295         }
 296
 297         if(optind < argc) {
 298                 fprintf(stderr, "%s: unrecognized argument '%s'\n", argv[0], argv[optind]);
 299                 usage(true);
 300                 goto exit_fail;
 301         }
 302
 303         if(!netname && (netname = getenv("NETNAME"))) {
 304                 netname = xstrdup(netname);
 305         }
 306
 307         /* netname "." is special: a "top-level name" */
 308
 309         if(netname && (!*netname || !strcmp(netname, "."))) {
 310                 free(netname);
 311                 netname = NULL;
 312         }
 313
 314         if(netname && !check_netname(netname, false)) {
 315                 fprintf(stderr, "Invalid character in netname!\n");
 316                 goto exit_fail;
 317         }
 318
 319         if(netname && !check_netname(netname, true)) {
 320                 fprintf(stderr, "Warning: unsafe character in netname!\n");
 321         }
 322
 323         return true;
 324
 325 exit_fail:
 326         free_names();
 327         list_empty_list(&cmdline_conf);
 328         return false;
 329 }
 330
 331 static bool read_sandbox_level(void) {
 332         sandbox_level_t level;
 333         char *value = NULL;
 334
 335         if(get_config_string(lookup_config(&config_tree, "Sandbox"), &value)) {
 336                 if(!strcasecmp("off", value)) {
 337                         level = SANDBOX_NONE;
 338                 } else if(!strcasecmp("normal", value)) {
 339                         level = SANDBOX_NORMAL;
 340                 } else if(!strcasecmp("high", value)) {
 341                         level = SANDBOX_HIGH;
 342                 } else {
 343                         logger(DEBUG_ALWAYS, LOG_ERR, "Bad sandbox value %s!", value);
 344                         free(value);
 345                         return false;
 346                 }
 347
 348                 free(value);
 349         } else {
 350 #ifdef HAVE_SANDBOX
 351                 level = SANDBOX_NORMAL;
 352 #else
 353                 level = SANDBOX_NONE;
 354 #endif
 355         }
 356
 357 #ifndef HAVE_SANDBOX
 358
 359         if(level > SANDBOX_NONE) {
 360                 logger(DEBUG_ALWAYS, LOG_ERR, "Sandbox is used but is not supported on this platform");
 361                 return false;
 362         }
 363
 364 #endif
 365         sandbox_set_level(level);
 366         return true;
 367 }
 368
 369 static bool drop_privs(void) {
 370 #ifndef HAVE_WINDOWS
 371         uid_t uid = 0;
 372
 373         if(switchuser) {
 374                 struct passwd *pw = getpwnam(switchuser);
 375
 376                 if(!pw) {
 377                         logger(DEBUG_ALWAYS, LOG_ERR, "unknown user `%s'", switchuser);
 378                         return false;
 379                 }
 380
 381                 uid = pw->pw_uid;
 382
 383                 // The second parameter to initgroups on macOS requires int,
 384                 // but __gid_t is unsigned int. There's not much we can do here.
 385                 if(initgroups(switchuser, pw->pw_gid) != 0 || // NOLINT(bugprone-narrowing-conversions)
 386                                 setgid(pw->pw_gid) != 0) {
 387                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
 388                                "initgroups", strerror(errno));
 389                         return false;
 390                 }
 391
 392 #ifndef __ANDROID__
 393 // Not supported in android NDK
 394                 endgrent();
 395                 endpwent();
 396 #endif
 397         }
 398
 399         if(do_chroot) {
 400                 tzset();        /* for proper timestamps in logs */
 401
 402                 if(chroot(confbase) != 0 || chdir("/") != 0) {
 403                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
 404                                "chroot", strerror(errno));
 405                         return false;
 406                 }
 407
 408                 free(confbase);
 409                 confbase = xstrdup("");
 410         }
 411
 412         if(switchuser)
 413                 if(setuid(uid) != 0) {
 414                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
 415                                "setuid", strerror(errno));
 416                         return false;
 417                 }
 418
 419 #endif // HAVE_WINDOWS
 420
 421         makedirs(DIR_CACHE | DIR_HOSTS | DIR_INVITATIONS);
 422
 423         return sandbox_enter();
 424 }
 425
 426 #ifdef HAVE_WINDOWS
 427 # define setpriority(level) !SetPriorityClass(GetCurrentProcess(), (level))
 428
 429 static void stop_handler(void *data, int flags) {
 430         (void)data;
 431         (void)flags;
 432
 433         event_exit();
 434 }
 435
 436 static BOOL WINAPI console_ctrl_handler(DWORD type) {
 437         (void)type;
 438
 439         logger(DEBUG_ALWAYS, LOG_NOTICE, "Got console shutdown request");
 440
 441         if(WSASetEvent(stop_io.event) == FALSE) {
 442                 abort();
 443         }
 444
 445         return TRUE;
 446 }
 447 #else
 448 # define NORMAL_PRIORITY_CLASS 0
 449 # define BELOW_NORMAL_PRIORITY_CLASS 10
 450 # define HIGH_PRIORITY_CLASS -10
 451 # define setpriority(level) (setpriority(PRIO_PROCESS, 0, (level)))
 452 #endif
 453
 454 static void cleanup(void) {
 455         splay_empty_tree(&config_tree);
 456         list_empty_list(&cmdline_conf);
 457         free_names();
 458 }
 459
 460 int main(int argc, char **argv) {
 461         program_name = argv[0];
 462
 463         if(!parse_options(argc, argv)) {
 464                 return 1;
 465         }
 466
 467         if(show_version) {
 468                 fprintf(stdout,
 469                         "%s version %s (built %s %s, protocol %d.%d)\n"
 470                         "Features:"
 471 #ifdef HAVE_OPENSSL
 472                         " openssl"
 473 #endif
 474 #ifdef HAVE_LIBGCRYPT
 475                         " libgcrypt"
 476 #endif
 477 #ifdef HAVE_LZO
 478                         " comp_lzo"
 479 #endif
 480 #ifdef HAVE_ZLIB
 481                         " comp_zlib"
 482 #endif
 483 #ifdef HAVE_LZ4
 484                         " comp_lz4"
 485 #endif
 486 #ifndef DISABLE_LEGACY
 487                         " legacy_protocol"
 488 #endif
 489 #ifdef ENABLE_JUMBOGRAMS
 490                         " jumbograms"
 491 #endif
 492 #ifdef ENABLE_TUNEMU
 493                         " tunemu"
 494 #endif
 495 #ifdef HAVE_MINIUPNPC
 496                         " miniupnpc"
 497 #endif
 498 #ifdef HAVE_SANDBOX
 499                         " sandbox"
 500 #endif
 501 #ifdef ENABLE_UML
 502                         " uml"
 503 #endif
 504 #ifdef ENABLE_VDE
 505                         " vde"
 506 #endif
 507                         "\n\n"
 508                         "Copyright (C) 1998-2021 Ivo Timmermans, Guus Sliepen and others.\n"
 509                         "See the AUTHORS file for a complete list.\n"
 510                         "\n"
 511                         "tinc comes with ABSOLUTELY NO WARRANTY.  This is free software,\n"
 512                         "and you are welcome to redistribute it under certain conditions;\n"
 513                         "see the file COPYING for details.\n",
 514                         PACKAGE, BUILD_VERSION, BUILD_DATE, BUILD_TIME, PROT_MAJOR, PROT_MINOR);
 515                 return 0;
 516         }
 517
 518         if(show_help) {
 519                 usage(false);
 520                 return 0;
 521         }
 522
 523         make_names(true);
 524         atexit(cleanup);
 525
 526         if(chdir(confbase) == -1) {
 527                 logger(DEBUG_ALWAYS, LOG_ERR, "Could not change to configuration directory: %s", strerror(errno));
 528                 return 1;
 529         }
 530
 531 #ifdef HAVE_WINDOWS
 532
 533         if(WSAStartup(MAKEWORD(2, 2), &wsa_state)) {
 534                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "WSAStartup", winerror(GetLastError()));
 535                 return 1;
 536         }
 537
 538 #else
 539         // Check if we got an umbilical fd from the process that started us
 540         char *umbstr = getenv("TINC_UMBILICAL");
 541
 542         if(umbstr) {
 543                 int colorize = 0;
 544                 sscanf(umbstr, "%d %d", &umbilical, &colorize);
 545                 umbilical_colorize = colorize;
 546
 547                 if(fcntl(umbilical, F_GETFL) < 0) {
 548                         umbilical = 0;
 549                 }
 550
 551 #ifdef FD_CLOEXEC
 552
 553                 if(umbilical) {
 554                         fcntl(umbilical, F_SETFD, FD_CLOEXEC);
 555                 }
 556
 557 #endif
 558         }
 559
 560 #endif
 561
 562         openlogger("tinc", use_logfile ? LOGMODE_FILE : LOGMODE_STDERR);
 563
 564         g_argv = argv;
 565
 566         if(getenv("LISTEN_PID") && atoi(getenv("LISTEN_PID")) == getpid()) {
 567                 do_detach = false;
 568         }
 569
 570 #ifdef HAVE_UNSETENV
 571         unsetenv("LISTEN_PID");
 572 #endif
 573
 574         gettimeofday(&now, NULL);
 575         random_init();
 576         crypto_init();
 577         prng_init();
 578
 579         if(!read_server_config(&config_tree)) {
 580                 return 1;
 581         }
 582
 583         if(!read_sandbox_level()) {
 584                 return 1;
 585         }
 586
 587         if(debug_level == DEBUG_NOTHING) {
 588                 int level = 0;
 589
 590                 if(get_config_int(lookup_config(&config_tree, "LogLevel"), &level)) {
 591                         debug_level = level;
 592                 }
 593         }
 594
 595 #ifdef HAVE_LZO
 596
 597         if(lzo_init() != LZO_E_OK) {
 598                 logger(DEBUG_ALWAYS, LOG_ERR, "Error initializing LZO compressor!");
 599                 return 1;
 600         }
 601
 602 #endif
 603
 604 #ifdef HAVE_WINDOWS
 605         io_add_event(&stop_io, stop_handler, NULL, WSACreateEvent());
 606
 607         if(stop_io.event == FALSE) {
 608                 abort();
 609         }
 610
 611         int result;
 612
 613         if(!do_detach || !init_service()) {
 614                 SetConsoleCtrlHandler(console_ctrl_handler, TRUE);
 615                 result = main2(argc, argv);
 616         } else {
 617                 result = 1;
 618         }
 619
 620         if(WSACloseEvent(stop_io.event) == FALSE) {
 621                 abort();
 622         }
 623
 624         io_del(&stop_io);
 625         return result;
 626 }
 627
 628 int main2(int argc, char **argv) {
 629         (void)argc;
 630         (void)argv;
 631 #endif
 632         char *priority = NULL;
 633
 634         if(!detach()) {
 635                 return 1;
 636         }
 637
 638 #ifdef HAVE_MLOCKALL
 639
 640         /* Lock all pages into memory if requested.
 641          * This has to be done after daemon()/fork() so it works for child.
 642          * No need to do that in parent as it's very short-lived. */
 643         if(do_mlock && mlockall(MCL_CURRENT | MCL_FUTURE) != 0) {
 644                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "mlockall",
 645                        strerror(errno));
 646                 return 1;
 647         }
 648
 649 #endif
 650
 651         /* Setup sockets and open device. */
 652
 653         if(!setup_network()) {
 654                 goto end;
 655         }
 656
 657         /* Change process priority */
 658
 659         if(get_config_string(lookup_config(&config_tree, "ProcessPriority"), &priority)) {
 660                 if(!strcasecmp(priority, "Normal")) {
 661                         if(setpriority(NORMAL_PRIORITY_CLASS) != 0) {
 662                                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setpriority", strerror(errno));
 663                                 goto end;
 664                         }
 665                 } else if(!strcasecmp(priority, "Low")) {
 666                         if(setpriority(BELOW_NORMAL_PRIORITY_CLASS) != 0) {
 667                                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setpriority", strerror(errno));
 668                                 goto end;
 669                         }
 670                 } else if(!strcasecmp(priority, "High")) {
 671                         if(setpriority(HIGH_PRIORITY_CLASS) != 0) {
 672                                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setpriority", strerror(errno));
 673                                 goto end;
 674                         }
 675                 } else {
 676                         logger(DEBUG_ALWAYS, LOG_ERR, "Invalid priority `%s`!", priority);
 677                         goto end;
 678                 }
 679         }
 680
 681         /* drop privileges */
 682         if(!drop_privs()) {
 683                 goto end;
 684         }
 685
 686         /* Start main loop. It only exits when tinc is killed. */
 687
 688         logger(DEBUG_ALWAYS, LOG_NOTICE, "Ready");
 689
 690         if(umbilical) { // snip!
 691                 if(write(umbilical, "", 1) != 1) {
 692                         // Pipe full or broken, nothing we can do about it.
 693                 }
 694
 695                 close(umbilical);
 696                 umbilical = 0;
 697         }
 698
 699         try_outgoing_connections();
 700
 701 #ifdef HAVE_WATCHDOG
 702         watchdog_start();
 703 #endif
 704
 705         status = main_loop();
 706
 707 #ifdef HAVE_WATCHDOG
 708         watchdog_stop();
 709 #endif
 710
 711         /* Shutdown properly. */
 712
 713 end:
 714         close_network_connections();
 715
 716         logger(DEBUG_ALWAYS, LOG_NOTICE, "Terminating");
 717
 718         free(priority);
 719
 720         random_exit();
 721
 722         return status;
 723 }