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