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
  60 /* If nonzero, display usage information and exit. */
  61 static bool show_help = false;
  62
  63 /* If nonzero, print the version on standard output and exit.  */
  64 static bool show_version = false;
  65
  66 #ifdef HAVE_MLOCKALL
  67 /* If nonzero, disable swapping for this process. */
  68 static bool do_mlock = false;
  69 #endif
  70
  71 #ifndef HAVE_WINDOWS
  72 /* If nonzero, chroot to netdir after startup. */
  73 static bool do_chroot = false;
  74
  75 /* If !NULL, do setuid to given user after startup */
  76 static const char *switchuser = NULL;
  77 #endif
  78
  79 char **g_argv;                  /* a copy of the cmdline arguments */
  80
  81 static int status = 1;
  82
  83 typedef enum option_t {
  84         OPT_BAD_OPTION  = '?',
  85         OPT_LONG_OPTION =  0,
  86
  87         // Short options
  88         OPT_CONFIG_FILE = 'c',
  89         OPT_NETNAME     = 'n',
  90         OPT_NO_DETACH   = 'D',
  91         OPT_DEBUG       = 'd',
  92         OPT_MLOCK       = 'L',
  93         OPT_CHROOT      = 'R',
  94         OPT_CHANGE_USER = 'U',
  95         OPT_SYSLOG      = 's',
  96         OPT_OPTION      = 'o',
  97
  98         // Long options
  99         OPT_HELP        = 255,
 100         OPT_VERSION,
 101         OPT_NO_SECURITY,
 102         OPT_LOGFILE,
 103         OPT_PIDFILE,
 104 } option_t;
 105
 106 static struct option const long_options[] = {
 107         {"config",          required_argument, NULL, OPT_CONFIG_FILE},
 108         {"net",             required_argument, NULL, OPT_NETNAME},
 109         {"no-detach",       no_argument,       NULL, OPT_NO_DETACH},
 110         {"debug",           optional_argument, NULL, OPT_DEBUG},
 111         {"mlock",           no_argument,       NULL, OPT_MLOCK},
 112         {"chroot",          no_argument,       NULL, OPT_CHROOT},
 113         {"user",            required_argument, NULL, OPT_CHANGE_USER},
 114         {"syslog",          no_argument,       NULL, OPT_SYSLOG},
 115         {"option",          required_argument, NULL, OPT_OPTION},
 116         {"help",            no_argument,       NULL, OPT_HELP},
 117         {"version",         no_argument,       NULL, OPT_VERSION},
 118         {"bypass-security", no_argument,       NULL, OPT_NO_SECURITY},
 119         {"logfile",         optional_argument, NULL, OPT_LOGFILE},
 120         {"pidfile",         required_argument, NULL, OPT_PIDFILE},
 121         {NULL,              0,                 NULL, 0},
 122 };
 123
 124 #ifdef HAVE_WINDOWS
 125 static struct WSAData wsa_state;
 126 int main2(int argc, char **argv);
 127 #endif
 128
 129 static void usage(bool status) {
 130         if(status)
 131                 fprintf(stderr, "Try `%s --help\' for more information.\n",
 132                         program_name);
 133         else {
 134                 fprintf(stdout,
 135                         "Usage: %s [option]...\n"
 136                         "\n"
 137                         "  -c, --config=DIR              Read configuration options from DIR.\n"
 138                         "  -D, --no-detach               Don't fork and detach.\n"
 139                         "  -d, --debug[=LEVEL]           Increase debug level or set it to LEVEL.\n"
 140                         "  -n, --net=NETNAME             Connect to net NETNAME.\n"
 141 #ifdef HAVE_MLOCKALL
 142                         "  -L, --mlock                   Lock tinc into main memory.\n"
 143 #endif
 144                         "      --logfile[=FILENAME]      Write log entries to a logfile.\n"
 145                         "  -s  --syslog                  Use syslog instead of stderr with --no-detach.\n"
 146                         "      --pidfile=FILENAME        Write PID and control socket cookie to FILENAME.\n"
 147                         "      --bypass-security         Disables meta protocol security, for debugging.\n"
 148                         "  -o, --option[HOST.]KEY=VALUE  Set global/host configuration value.\n"
 149 #ifndef HAVE_WINDOWS
 150                         "  -R, --chroot                  chroot to NET dir at startup.\n"
 151                         "  -U, --user=USER               setuid to given USER at startup.\n"
 152 #endif
 153                         "      --help                    Display this help and exit.\n"
 154                         "      --version                 Output version information and exit.\n"
 155                         "\n"
 156                         "Report bugs to tinc@tinc-vpn.org.\n",
 157                         program_name);
 158         }
 159 }
 160
 161 // Try to resolve path to absolute, return a copy of the argument if this fails.
 162 static char *get_path_arg(char *arg) {
 163         char *result = absolute_path(arg);
 164
 165         if(!result) {
 166                 result = xstrdup(arg);
 167         }
 168
 169         return result;
 170 }
 171
 172 static bool parse_options(int argc, char **argv) {
 173         config_t *cfg;
 174         int r;
 175         int option_index = 0;
 176         int lineno = 0;
 177
 178         while((r = getopt_long(argc, argv, "c:DLd::n:so:RU:", long_options, &option_index)) != EOF) {
 179                 switch((option_t) r) {
 180                 case OPT_LONG_OPTION:
 181                         break;
 182
 183                 case OPT_BAD_OPTION:
 184                         usage(true);
 185                         goto exit_fail;
 186
 187                 case OPT_CONFIG_FILE:
 188                         assert(optarg);
 189                         free(confbase);
 190                         confbase = get_path_arg(optarg);
 191                         break;
 192
 193                 case OPT_NO_DETACH:
 194                         do_detach = false;
 195                         break;
 196
 197                 case OPT_MLOCK: /* lock tincd into RAM */
 198 #ifndef HAVE_MLOCKALL
 199                         logger(DEBUG_ALWAYS, LOG_ERR, "The %s option is not supported on this platform.", argv[optind - 1]);
 200                         goto exit_fail;
 201 #else
 202                         do_mlock = true;
 203                         break;
 204 #endif
 205
 206                 case OPT_DEBUG: /* increase debug level */
 207                         if(!optarg && optind < argc && *argv[optind] != '-') {
 208                                 optarg = argv[optind++];
 209                         }
 210
 211                         if(optarg) {
 212                                 debug_level = atoi(optarg);
 213                         } else {
 214                                 debug_level++;
 215                         }
 216
 217                         break;
 218
 219                 case OPT_NETNAME:
 220                         assert(optarg);
 221                         free(netname);
 222                         netname = xstrdup(optarg);
 223                         break;
 224
 225                 case OPT_SYSLOG:
 226                         use_logfile = false;
 227                         use_syslog = true;
 228                         break;
 229
 230                 case OPT_OPTION:
 231                         cfg = parse_config_line(optarg, NULL, ++lineno);
 232
 233                         if(!cfg) {
 234                                 goto exit_fail;
 235                         }
 236
 237                         list_insert_tail(&cmdline_conf, cfg);
 238                         break;
 239
 240 #ifdef HAVE_WINDOWS
 241
 242                 case OPT_CHANGE_USER:
 243                 case OPT_CHROOT:
 244                         logger(DEBUG_ALWAYS, LOG_ERR, "The %s option is not supported on this platform.", argv[optind - 1]);
 245                         goto exit_fail;
 246 #else
 247
 248                 case OPT_CHROOT:
 249                         do_chroot = true;
 250                         break;
 251
 252                 case OPT_CHANGE_USER:
 253                         switchuser = optarg;
 254                         break;
 255 #endif
 256
 257                 case OPT_HELP:
 258                         show_help = true;
 259                         break;
 260
 261                 case OPT_VERSION:
 262                         show_version = true;
 263                         break;
 264
 265                 case OPT_NO_SECURITY:
 266                         bypass_security = true;
 267                         break;
 268
 269                 case OPT_LOGFILE:
 270                         use_syslog = false;
 271                         use_logfile = true;
 272
 273                         if(!optarg && optind < argc && *argv[optind] != '-') {
 274                                 optarg = argv[optind++];
 275                         }
 276
 277                         if(optarg) {
 278                                 free(logfilename);
 279                                 logfilename = get_path_arg(optarg);
 280                         }
 281
 282                         break;
 283
 284                 case OPT_PIDFILE:
 285                         assert(optarg);
 286                         free(pidfilename);
 287                         pidfilename = get_path_arg(optarg);
 288                         break;
 289
 290                 default:
 291                         break;
 292                 }
 293         }
 294
 295         if(optind < argc) {
 296                 fprintf(stderr, "%s: unrecognized argument '%s'\n", argv[0], argv[optind]);
 297                 usage(true);
 298                 goto exit_fail;
 299         }
 300
 301         if(!netname && (netname = getenv("NETNAME"))) {
 302                 netname = xstrdup(netname);
 303         }
 304
 305         /* netname "." is special: a "top-level name" */
 306
 307         if(netname && (!*netname || !strcmp(netname, "."))) {
 308                 free(netname);
 309                 netname = NULL;
 310         }
 311
 312         if(netname && !check_netname(netname, false)) {
 313                 fprintf(stderr, "Invalid character in netname!\n");
 314                 goto exit_fail;
 315         }
 316
 317         if(netname && !check_netname(netname, true)) {
 318                 fprintf(stderr, "Warning: unsafe character in netname!\n");
 319         }
 320
 321         return true;
 322
 323 exit_fail:
 324         free_names();
 325         list_empty_list(&cmdline_conf);
 326         return false;
 327 }
 328
 329 static bool read_sandbox_level(void) {
 330         sandbox_level_t level;
 331         char *value = NULL;
 332
 333         if(get_config_string(lookup_config(&config_tree, "Sandbox"), &value)) {
 334                 if(!strcasecmp("off", value)) {
 335                         level = SANDBOX_NONE;
 336                 } else if(!strcasecmp("normal", value)) {
 337                         level = SANDBOX_NORMAL;
 338                 } else if(!strcasecmp("high", value)) {
 339                         level = SANDBOX_HIGH;
 340                 } else {
 341                         logger(DEBUG_ALWAYS, LOG_ERR, "Bad sandbox value %s!", value);
 342                         free(value);
 343                         return false;
 344                 }
 345
 346                 free(value);
 347         } else {
 348 #ifdef HAVE_SANDBOX
 349                 level = SANDBOX_NORMAL;
 350 #else
 351                 level = SANDBOX_NONE;
 352 #endif
 353         }
 354
 355 #ifndef HAVE_SANDBOX
 356
 357         if(level > SANDBOX_NONE) {
 358                 logger(DEBUG_ALWAYS, LOG_ERR, "Sandbox is used but is not supported on this platform");
 359                 return false;
 360         }
 361
 362 #endif
 363         sandbox_set_level(level);
 364         return true;
 365 }
 366
 367 static bool drop_privs(void) {
 368 #ifndef HAVE_WINDOWS
 369         uid_t uid = 0;
 370
 371         if(switchuser) {
 372                 struct passwd *pw = getpwnam(switchuser);
 373
 374                 if(!pw) {
 375                         logger(DEBUG_ALWAYS, LOG_ERR, "unknown user `%s'", switchuser);
 376                         return false;
 377                 }
 378
 379                 uid = pw->pw_uid;
 380
 381                 // The second parameter to initgroups on macOS requires int,
 382                 // but __gid_t is unsigned int. There's not much we can do here.
 383                 if(initgroups(switchuser, pw->pw_gid) != 0 || // NOLINT(bugprone-narrowing-conversions)
 384                                 setgid(pw->pw_gid) != 0) {
 385                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
 386                                "initgroups", strerror(errno));
 387                         return false;
 388                 }
 389
 390 #ifndef __ANDROID__
 391 // Not supported in android NDK
 392                 endgrent();
 393                 endpwent();
 394 #endif
 395         }
 396
 397         if(do_chroot) {
 398                 tzset();        /* for proper timestamps in logs */
 399
 400                 if(chroot(confbase) != 0 || chdir("/") != 0) {
 401                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
 402                                "chroot", strerror(errno));
 403                         return false;
 404                 }
 405
 406                 free(confbase);
 407                 confbase = xstrdup("");
 408         }
 409
 410         if(switchuser)
 411                 if(setuid(uid) != 0) {
 412                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
 413                                "setuid", strerror(errno));
 414                         return false;
 415                 }
 416
 417 #endif
 418
 419         return sandbox_enter();
 420 }
 421
 422 #ifdef HAVE_WINDOWS
 423 # define setpriority(level) !SetPriorityClass(GetCurrentProcess(), (level))
 424
 425 static void stop_handler(void *data, int flags) {
 426         (void)data;
 427         (void)flags;
 428
 429         event_exit();
 430 }
 431
 432 static BOOL WINAPI console_ctrl_handler(DWORD type) {
 433         (void)type;
 434
 435         logger(DEBUG_ALWAYS, LOG_NOTICE, "Got console shutdown request");
 436
 437         if(WSASetEvent(stop_io.event) == FALSE) {
 438                 abort();
 439         }
 440
 441         return TRUE;
 442 }
 443 #else
 444 # define NORMAL_PRIORITY_CLASS 0
 445 # define BELOW_NORMAL_PRIORITY_CLASS 10
 446 # define HIGH_PRIORITY_CLASS -10
 447 # define setpriority(level) (setpriority(PRIO_PROCESS, 0, (level)))
 448 #endif
 449
 450 static void cleanup(void) {
 451         splay_empty_tree(&config_tree);
 452         list_empty_list(&cmdline_conf);
 453         free_names();
 454 }
 455
 456 int main(int argc, char **argv) {
 457         program_name = argv[0];
 458
 459         if(!parse_options(argc, argv)) {
 460                 return 1;
 461         }
 462
 463         if(show_version) {
 464                 fprintf(stdout,
 465                         "%s version %s (built %s %s, protocol %d.%d)\n"
 466                         "Features:"
 467 #ifdef HAVE_OPENSSL
 468                         " openssl"
 469 #endif
 470 #ifdef HAVE_LIBGCRYPT
 471                         " libgcrypt"
 472 #endif
 473 #ifdef HAVE_LZO
 474                         " comp_lzo"
 475 #endif
 476 #ifdef HAVE_ZLIB
 477                         " comp_zlib"
 478 #endif
 479 #ifdef HAVE_LZ4
 480                         " comp_lz4"
 481 #endif
 482 #ifndef DISABLE_LEGACY
 483                         " legacy_protocol"
 484 #endif
 485 #ifdef ENABLE_JUMBOGRAMS
 486                         " jumbograms"
 487 #endif
 488 #ifdef ENABLE_TUNEMU
 489                         " tunemu"
 490 #endif
 491 #ifdef HAVE_MINIUPNPC
 492                         " miniupnpc"
 493 #endif
 494 #ifdef HAVE_SANDBOX
 495                         " sandbox"
 496 #endif
 497 #ifdef ENABLE_UML
 498                         " uml"
 499 #endif
 500 #ifdef ENABLE_VDE
 501                         " vde"
 502 #endif
 503                         "\n\n"
 504                         "Copyright (C) 1998-2021 Ivo Timmermans, Guus Sliepen and others.\n"
 505                         "See the AUTHORS file for a complete list.\n"
 506                         "\n"
 507                         "tinc comes with ABSOLUTELY NO WARRANTY.  This is free software,\n"
 508                         "and you are welcome to redistribute it under certain conditions;\n"
 509                         "see the file COPYING for details.\n",
 510                         PACKAGE, BUILD_VERSION, BUILD_DATE, BUILD_TIME, PROT_MAJOR, PROT_MINOR);
 511                 return 0;
 512         }
 513
 514         if(show_help) {
 515                 usage(false);
 516                 return 0;
 517         }
 518
 519         make_names(true);
 520         atexit(cleanup);
 521
 522         if(chdir(confbase) == -1) {
 523                 logger(DEBUG_ALWAYS, LOG_ERR, "Could not change to configuration directory: %s", strerror(errno));
 524                 return 1;
 525         }
 526
 527 #ifdef HAVE_WINDOWS
 528
 529         if(WSAStartup(MAKEWORD(2, 2), &wsa_state)) {
 530                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "WSAStartup", winerror(GetLastError()));
 531                 return 1;
 532         }
 533
 534 #else
 535         // Check if we got an umbilical fd from the process that started us
 536         char *umbstr = getenv("TINC_UMBILICAL");
 537
 538         if(umbstr) {
 539                 int colorize = 0;
 540                 sscanf(umbstr, "%d %d", &umbilical, &colorize);
 541                 umbilical_colorize = colorize;
 542
 543                 if(fcntl(umbilical, F_GETFL) < 0) {
 544                         umbilical = 0;
 545                 }
 546
 547 #ifdef FD_CLOEXEC
 548
 549                 if(umbilical) {
 550                         fcntl(umbilical, F_SETFD, FD_CLOEXEC);
 551                 }
 552
 553 #endif
 554         }
 555
 556 #endif
 557
 558         openlogger("tinc", use_logfile ? LOGMODE_FILE : LOGMODE_STDERR);
 559
 560         g_argv = argv;
 561
 562         if(getenv("LISTEN_PID") && atoi(getenv("LISTEN_PID")) == getpid()) {
 563                 do_detach = false;
 564         }
 565
 566 #ifdef HAVE_UNSETENV
 567         unsetenv("LISTEN_PID");
 568 #endif
 569
 570         gettimeofday(&now, NULL);
 571         random_init();
 572         crypto_init();
 573         prng_init();
 574
 575         if(!read_server_config(&config_tree)) {
 576                 return 1;
 577         }
 578
 579         if(!read_sandbox_level()) {
 580                 return 1;
 581         }
 582
 583         if(debug_level == DEBUG_NOTHING) {
 584                 int level = 0;
 585
 586                 if(get_config_int(lookup_config(&config_tree, "LogLevel"), &level)) {
 587                         debug_level = level;
 588                 }
 589         }
 590
 591 #ifdef HAVE_LZO
 592
 593         if(lzo_init() != LZO_E_OK) {
 594                 logger(DEBUG_ALWAYS, LOG_ERR, "Error initializing LZO compressor!");
 595                 return 1;
 596         }
 597
 598 #endif
 599
 600 #ifdef HAVE_WINDOWS
 601         io_add_event(&stop_io, stop_handler, NULL, WSACreateEvent());
 602
 603         if(stop_io.event == FALSE) {
 604                 abort();
 605         }
 606
 607         int result;
 608
 609         if(!do_detach || !init_service()) {
 610                 SetConsoleCtrlHandler(console_ctrl_handler, TRUE);
 611                 result = main2(argc, argv);
 612         } else {
 613                 result = 1;
 614         }
 615
 616         if(WSACloseEvent(stop_io.event) == FALSE) {
 617                 abort();
 618         }
 619
 620         io_del(&stop_io);
 621         return result;
 622 }
 623
 624 int main2(int argc, char **argv) {
 625         (void)argc;
 626         (void)argv;
 627 #endif
 628         char *priority = NULL;
 629
 630         if(!detach()) {
 631                 return 1;
 632         }
 633
 634 #ifdef HAVE_MLOCKALL
 635
 636         /* Lock all pages into memory if requested.
 637          * This has to be done after daemon()/fork() so it works for child.
 638          * No need to do that in parent as it's very short-lived. */
 639         if(do_mlock && mlockall(MCL_CURRENT | MCL_FUTURE) != 0) {
 640                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "mlockall",
 641                        strerror(errno));
 642                 return 1;
 643         }
 644
 645 #endif
 646
 647         /* Setup sockets and open device. */
 648
 649         if(!setup_network()) {
 650                 goto end;
 651         }
 652
 653         /* Change process priority */
 654
 655         if(get_config_string(lookup_config(&config_tree, "ProcessPriority"), &priority)) {
 656                 if(!strcasecmp(priority, "Normal")) {
 657                         if(setpriority(NORMAL_PRIORITY_CLASS) != 0) {
 658                                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setpriority", strerror(errno));
 659                                 goto end;
 660                         }
 661                 } else if(!strcasecmp(priority, "Low")) {
 662                         if(setpriority(BELOW_NORMAL_PRIORITY_CLASS) != 0) {
 663                                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setpriority", strerror(errno));
 664                                 goto end;
 665                         }
 666                 } else if(!strcasecmp(priority, "High")) {
 667                         if(setpriority(HIGH_PRIORITY_CLASS) != 0) {
 668                                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setpriority", strerror(errno));
 669                                 goto end;
 670                         }
 671                 } else {
 672                         logger(DEBUG_ALWAYS, LOG_ERR, "Invalid priority `%s`!", priority);
 673                         goto end;
 674                 }
 675         }
 676
 677         /* drop privileges */
 678         if(!drop_privs()) {
 679                 goto end;
 680         }
 681
 682         /* Start main loop. It only exits when tinc is killed. */
 683
 684         logger(DEBUG_ALWAYS, LOG_NOTICE, "Ready");
 685
 686         if(umbilical) { // snip!
 687                 if(write(umbilical, "", 1) != 1) {
 688                         // Pipe full or broken, nothing we can do about it.
 689                 }
 690
 691                 close(umbilical);
 692                 umbilical = 0;
 693         }
 694
 695         try_outgoing_connections();
 696
 697         status = main_loop();
 698
 699         /* Shutdown properly. */
 700
 701 end:
 702         close_network_connections();
 703
 704         logger(DEBUG_ALWAYS, LOG_NOTICE, "Terminating");
 705
 706         free(priority);
 707
 708         random_exit();
 709
 710         return status;
 711 }