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
  61 /* If nonzero, display usage information and exit. */
  62 static bool show_help = false;
  63
  64 /* If nonzero, print the version on standard output and exit.  */
  65 static bool show_version = false;
  66
  67 #ifdef HAVE_MLOCKALL
  68 /* If nonzero, disable swapping for this process. */
  69 static bool do_mlock = false;
  70 #endif
  71
  72 #ifndef HAVE_WINDOWS
  73 /* If nonzero, chroot to netdir after startup. */
  74 static bool do_chroot = false;
  75
  76 /* If !NULL, do setuid to given user after startup */
  77 static const char *switchuser = NULL;
  78 #endif
  79
  80 char **g_argv;                  /* a copy of the cmdline arguments */
  81
  82 static int status = 1;
  83
  84 typedef enum option_t {
  85         OPT_BAD_OPTION  = '?',
  86         OPT_LONG_OPTION =  0,
  87
  88         // Short options
  89         OPT_CONFIG_FILE = 'c',
  90         OPT_NETNAME     = 'n',
  91         OPT_NO_DETACH   = 'D',
  92         OPT_DEBUG       = 'd',
  93         OPT_MLOCK       = 'L',
  94         OPT_CHROOT      = 'R',
  95         OPT_CHANGE_USER = 'U',
  96         OPT_SYSLOG      = 's',
  97         OPT_OPTION      = 'o',
  98
  99         // Long options
 100         OPT_HELP        = 255,
 101         OPT_VERSION,
 102         OPT_NO_SECURITY,
 103         OPT_LOGFILE,
 104         OPT_PIDFILE,
 105 } option_t;
 106
 107 static struct option const long_options[] = {
 108         {"config",          required_argument, NULL, OPT_CONFIG_FILE},
 109         {"net",             required_argument, NULL, OPT_NETNAME},
 110         {"no-detach",       no_argument,       NULL, OPT_NO_DETACH},
 111         {"debug",           optional_argument, NULL, OPT_DEBUG},
 112         {"mlock",           no_argument,       NULL, OPT_MLOCK},
 113         {"chroot",          no_argument,       NULL, OPT_CHROOT},
 114         {"user",            required_argument, NULL, OPT_CHANGE_USER},
 115         {"syslog",          no_argument,       NULL, OPT_SYSLOG},
 116         {"option",          required_argument, NULL, OPT_OPTION},
 117         {"help",            no_argument,       NULL, OPT_HELP},
 118         {"version",         no_argument,       NULL, OPT_VERSION},
 119         {"bypass-security", no_argument,       NULL, OPT_NO_SECURITY},
 120         {"logfile",         optional_argument, NULL, OPT_LOGFILE},
 121         {"pidfile",         required_argument, NULL, OPT_PIDFILE},
 122         {NULL,              0,                 NULL, 0},
 123 };
 124
 125 #ifdef HAVE_WINDOWS
 126 static struct WSAData wsa_state;
 127 int main2(int argc, char **argv);
 128 #endif
 129
 130 static void usage(bool status) {
 131         if(status)
 132                 fprintf(stderr, "Try `%s --help\' for more information.\n",
 133                         program_name);
 134         else {
 135                 fprintf(stdout,
 136                         "Usage: %s [option]...\n"
 137                         "\n"
 138                         "  -c, --config=DIR              Read configuration options from DIR.\n"
 139                         "  -D, --no-detach               Don't fork and detach.\n"
 140                         "  -d, --debug[=LEVEL]           Increase debug level or set it to LEVEL.\n"
 141                         "  -n, --net=NETNAME             Connect to net NETNAME.\n"
 142 #ifdef HAVE_MLOCKALL
 143                         "  -L, --mlock                   Lock tinc into main memory.\n"
 144 #endif
 145                         "      --logfile[=FILENAME]      Write log entries to a logfile.\n"
 146                         "  -s  --syslog                  Use syslog instead of stderr with --no-detach.\n"
 147                         "      --pidfile=FILENAME        Write PID and control socket cookie to FILENAME.\n"
 148                         "      --bypass-security         Disables meta protocol security, for debugging.\n"
 149                         "  -o, --option[HOST.]KEY=VALUE  Set global/host configuration value.\n"
 150 #ifndef HAVE_WINDOWS
 151                         "  -R, --chroot                  chroot to NET dir at startup.\n"
 152                         "  -U, --user=USER               setuid to given USER at startup.\n"
 153 #endif
 154                         "      --help                    Display this help and exit.\n"
 155                         "      --version                 Output version information and exit.\n"
 156                         "\n"
 157                         "Report bugs to tinc@tinc-vpn.org.\n",
 158                         program_name);
 159         }
 160 }
 161
 162 // Try to resolve path to absolute, return a copy of the argument if this fails.
 163 static char *get_path_arg(char *arg) {
 164         char *result = absolute_path(arg);
 165
 166         if(!result) {
 167                 result = xstrdup(arg);
 168         }
 169
 170         return result;
 171 }
 172
 173 static bool parse_options(int argc, char **argv) {
 174         config_t *cfg;
 175         int r;
 176         int option_index = 0;
 177         int lineno = 0;
 178
 179         while((r = getopt_long(argc, argv, "c:DLd::n:so:RU:", long_options, &option_index)) != EOF) {
 180                 switch((option_t) r) {
 181                 case OPT_LONG_OPTION:
 182                         break;
 183
 184                 case OPT_BAD_OPTION:
 185                         usage(true);
 186                         goto exit_fail;
 187
 188                 case OPT_CONFIG_FILE:
 189                         assert(optarg);
 190                         free(confbase);
 191                         confbase = get_path_arg(optarg);
 192                         break;
 193
 194                 case OPT_NO_DETACH:
 195                         do_detach = false;
 196                         break;
 197
 198                 case OPT_MLOCK: /* lock tincd into RAM */
 199 #ifndef HAVE_MLOCKALL
 200                         logger(DEBUG_ALWAYS, LOG_ERR, "The %s option is not supported on this platform.", argv[optind - 1]);
 201                         goto exit_fail;
 202 #else
 203                         do_mlock = true;
 204                         break;
 205 #endif
 206
 207                 case OPT_DEBUG: /* increase debug level */
 208                         if(!optarg && optind < argc && *argv[optind] != '-') {
 209                                 optarg = argv[optind++];
 210                         }
 211
 212                         if(optarg) {
 213                                 debug_level = atoi(optarg);
 214                         } else {
 215                                 debug_level++;
 216                         }
 217
 218                         break;
 219
 220                 case OPT_NETNAME:
 221                         assert(optarg);
 222                         free(netname);
 223                         netname = xstrdup(optarg);
 224                         break;
 225
 226                 case OPT_SYSLOG:
 227                         use_logfile = false;
 228                         use_syslog = true;
 229                         break;
 230
 231                 case OPT_OPTION:
 232                         cfg = parse_config_line(optarg, NULL, ++lineno);
 233
 234                         if(!cfg) {
 235                                 goto exit_fail;
 236                         }
 237
 238                         list_insert_tail(&cmdline_conf, cfg);
 239                         break;
 240
 241 #ifdef HAVE_WINDOWS
 242
 243                 case OPT_CHANGE_USER:
 244                 case OPT_CHROOT:
 245                         logger(DEBUG_ALWAYS, LOG_ERR, "The %s option is not supported on this platform.", argv[optind - 1]);
 246                         goto exit_fail;
 247 #else
 248
 249                 case OPT_CHROOT:
 250                         do_chroot = true;
 251                         break;
 252
 253                 case OPT_CHANGE_USER:
 254                         switchuser = optarg;
 255                         break;
 256 #endif
 257
 258                 case OPT_HELP:
 259                         show_help = true;
 260                         break;
 261
 262                 case OPT_VERSION:
 263                         show_version = true;
 264                         break;
 265
 266                 case OPT_NO_SECURITY:
 267                         bypass_security = true;
 268                         break;
 269
 270                 case OPT_LOGFILE:
 271                         use_syslog = false;
 272                         use_logfile = true;
 273
 274                         if(!optarg && optind < argc && *argv[optind] != '-') {
 275                                 optarg = argv[optind++];
 276                         }
 277
 278                         if(optarg) {
 279                                 free(logfilename);
 280                                 logfilename = get_path_arg(optarg);
 281                         }
 282
 283                         break;
 284
 285                 case OPT_PIDFILE:
 286                         assert(optarg);
 287                         free(pidfilename);
 288                         pidfilename = get_path_arg(optarg);
 289                         break;
 290
 291                 default:
 292                         break;
 293                 }
 294         }
 295
 296         if(optind < argc) {
 297                 fprintf(stderr, "%s: unrecognized argument '%s'\n", argv[0], argv[optind]);
 298                 usage(true);
 299                 goto exit_fail;
 300         }
 301
 302         if(!netname && (netname = getenv("NETNAME"))) {
 303                 netname = xstrdup(netname);
 304         }
 305
 306         /* netname "." is special: a "top-level name" */
 307
 308         if(netname && (!*netname || !strcmp(netname, "."))) {
 309                 free(netname);
 310                 netname = NULL;
 311         }
 312
 313         if(netname && !check_netname(netname, false)) {
 314                 fprintf(stderr, "Invalid character in netname!\n");
 315                 goto exit_fail;
 316         }
 317
 318         if(netname && !check_netname(netname, true)) {
 319                 fprintf(stderr, "Warning: unsafe character in netname!\n");
 320         }
 321
 322         return true;
 323
 324 exit_fail:
 325         free_names();
 326         list_empty_list(&cmdline_conf);
 327         return false;
 328 }
 329
 330 static bool read_sandbox_level(void) {
 331         sandbox_level_t level;
 332         char *value = NULL;
 333
 334         if(get_config_string(lookup_config(&config_tree, "Sandbox"), &value)) {
 335                 if(!strcasecmp("off", value)) {
 336                         level = SANDBOX_NONE;
 337                 } else if(!strcasecmp("normal", value)) {
 338                         level = SANDBOX_NORMAL;
 339                 } else if(!strcasecmp("high", value)) {
 340                         level = SANDBOX_HIGH;
 341                 } else {
 342                         logger(DEBUG_ALWAYS, LOG_ERR, "Bad sandbox value %s!", value);
 343                         free(value);
 344                         return false;
 345                 }
 346
 347                 free(value);
 348         } else {
 349 #ifdef HAVE_SANDBOX
 350                 level = SANDBOX_NORMAL;
 351 #else
 352                 level = SANDBOX_NONE;
 353 #endif
 354         }
 355
 356 #ifndef HAVE_SANDBOX
 357
 358         if(level > SANDBOX_NONE) {
 359                 logger(DEBUG_ALWAYS, LOG_ERR, "Sandbox is used but is not supported on this platform");
 360                 return false;
 361         }
 362
 363 #endif
 364         sandbox_set_level(level);
 365         return true;
 366 }
 367
 368 static bool drop_privs(void) {
 369 #ifndef HAVE_WINDOWS
 370         uid_t uid = 0;
 371
 372         if(switchuser) {
 373                 struct passwd *pw = getpwnam(switchuser);
 374
 375                 if(!pw) {
 376                         logger(DEBUG_ALWAYS, LOG_ERR, "unknown user `%s'", switchuser);
 377                         return false;
 378                 }
 379
 380                 uid = pw->pw_uid;
 381
 382                 // The second parameter to initgroups on macOS requires int,
 383                 // but __gid_t is unsigned int. There's not much we can do here.
 384                 if(initgroups(switchuser, pw->pw_gid) != 0 || // NOLINT(bugprone-narrowing-conversions)
 385                                 setgid(pw->pw_gid) != 0) {
 386                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
 387                                "initgroups", strerror(errno));
 388                         return false;
 389                 }
 390
 391 #ifndef __ANDROID__
 392 // Not supported in android NDK
 393                 endgrent();
 394                 endpwent();
 395 #endif
 396         }
 397
 398         if(do_chroot) {
 399                 tzset();        /* for proper timestamps in logs */
 400
 401                 if(chroot(confbase) != 0 || chdir("/") != 0) {
 402                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
 403                                "chroot", strerror(errno));
 404                         return false;
 405                 }
 406
 407                 free(confbase);
 408                 confbase = xstrdup("");
 409         }
 410
 411         if(switchuser)
 412                 if(setuid(uid) != 0) {
 413                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
 414                                "setuid", strerror(errno));
 415                         return false;
 416                 }
 417
 418 #endif
 419
 420         return sandbox_enter();
 421 }
 422
 423 #ifdef HAVE_WINDOWS
 424 # define setpriority(level) !SetPriorityClass(GetCurrentProcess(), (level))
 425
 426 static void stop_handler(void *data, int flags) {
 427         (void)data;
 428         (void)flags;
 429
 430         event_exit();
 431 }
 432
 433 static BOOL WINAPI console_ctrl_handler(DWORD type) {
 434         (void)type;
 435
 436         logger(DEBUG_ALWAYS, LOG_NOTICE, "Got console shutdown request");
 437
 438         if(WSASetEvent(stop_io.event) == FALSE) {
 439                 abort();
 440         }
 441
 442         return TRUE;
 443 }
 444 #else
 445 # define NORMAL_PRIORITY_CLASS 0
 446 # define BELOW_NORMAL_PRIORITY_CLASS 10
 447 # define HIGH_PRIORITY_CLASS -10
 448 # define setpriority(level) (setpriority(PRIO_PROCESS, 0, (level)))
 449 #endif
 450
 451 static void cleanup(void) {
 452         splay_empty_tree(&config_tree);
 453         list_empty_list(&cmdline_conf);
 454         free_names();
 455 }
 456
 457 int main(int argc, char **argv) {
 458         program_name = argv[0];
 459
 460         if(!parse_options(argc, argv)) {
 461                 return 1;
 462         }
 463
 464         if(show_version) {
 465                 fprintf(stdout,
 466                         "%s version %s (built %s %s, protocol %d.%d)\n"
 467                         "Features:"
 468 #ifdef HAVE_OPENSSL
 469                         " openssl"
 470 #endif
 471 #ifdef HAVE_LIBGCRYPT
 472                         " libgcrypt"
 473 #endif
 474 #ifdef HAVE_LZO
 475                         " comp_lzo"
 476 #endif
 477 #ifdef HAVE_ZLIB
 478                         " comp_zlib"
 479 #endif
 480 #ifdef HAVE_LZ4
 481                         " comp_lz4"
 482 #endif
 483 #ifndef DISABLE_LEGACY
 484                         " legacy_protocol"
 485 #endif
 486 #ifdef ENABLE_JUMBOGRAMS
 487                         " jumbograms"
 488 #endif
 489 #ifdef ENABLE_TUNEMU
 490                         " tunemu"
 491 #endif
 492 #ifdef HAVE_MINIUPNPC
 493                         " miniupnpc"
 494 #endif
 495 #ifdef HAVE_SANDBOX
 496                         " sandbox"
 497 #endif
 498 #ifdef ENABLE_UML
 499                         " uml"
 500 #endif
 501 #ifdef ENABLE_VDE
 502                         " vde"
 503 #endif
 504                         "\n\n"
 505                         "Copyright (C) 1998-2021 Ivo Timmermans, Guus Sliepen and others.\n"
 506                         "See the AUTHORS file for a complete list.\n"
 507                         "\n"
 508                         "tinc comes with ABSOLUTELY NO WARRANTY.  This is free software,\n"
 509                         "and you are welcome to redistribute it under certain conditions;\n"
 510                         "see the file COPYING for details.\n",
 511                         PACKAGE, BUILD_VERSION, BUILD_DATE, BUILD_TIME, PROT_MAJOR, PROT_MINOR);
 512                 return 0;
 513         }
 514
 515         if(show_help) {
 516                 usage(false);
 517                 return 0;
 518         }
 519
 520         make_names(true);
 521         atexit(cleanup);
 522
 523         if(chdir(confbase) == -1) {
 524                 logger(DEBUG_ALWAYS, LOG_ERR, "Could not change to configuration directory: %s", strerror(errno));
 525                 return 1;
 526         }
 527
 528 #ifdef HAVE_WINDOWS
 529
 530         if(WSAStartup(MAKEWORD(2, 2), &wsa_state)) {
 531                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "WSAStartup", winerror(GetLastError()));
 532                 return 1;
 533         }
 534
 535 #else
 536         // Check if we got an umbilical fd from the process that started us
 537         char *umbstr = getenv("TINC_UMBILICAL");
 538
 539         if(umbstr) {
 540                 int colorize = 0;
 541                 sscanf(umbstr, "%d %d", &umbilical, &colorize);
 542                 umbilical_colorize = colorize;
 543
 544                 if(fcntl(umbilical, F_GETFL) < 0) {
 545                         umbilical = 0;
 546                 }
 547
 548 #ifdef FD_CLOEXEC
 549
 550                 if(umbilical) {
 551                         fcntl(umbilical, F_SETFD, FD_CLOEXEC);
 552                 }
 553
 554 #endif
 555         }
 556
 557 #endif
 558
 559         openlogger("tinc", use_logfile ? LOGMODE_FILE : LOGMODE_STDERR);
 560
 561         g_argv = argv;
 562
 563         if(getenv("LISTEN_PID") && atoi(getenv("LISTEN_PID")) == getpid()) {
 564                 do_detach = false;
 565         }
 566
 567 #ifdef HAVE_UNSETENV
 568         unsetenv("LISTEN_PID");
 569 #endif
 570
 571         gettimeofday(&now, NULL);
 572         random_init();
 573         crypto_init();
 574         prng_init();
 575
 576         if(!read_server_config(&config_tree)) {
 577                 return 1;
 578         }
 579
 580         if(!read_sandbox_level()) {
 581                 return 1;
 582         }
 583
 584         if(debug_level == DEBUG_NOTHING) {
 585                 int level = 0;
 586
 587                 if(get_config_int(lookup_config(&config_tree, "LogLevel"), &level)) {
 588                         debug_level = level;
 589                 }
 590         }
 591
 592 #ifdef HAVE_LZO
 593
 594         if(lzo_init() != LZO_E_OK) {
 595                 logger(DEBUG_ALWAYS, LOG_ERR, "Error initializing LZO compressor!");
 596                 return 1;
 597         }
 598
 599 #endif
 600
 601 #ifdef HAVE_WINDOWS
 602         io_add_event(&stop_io, stop_handler, NULL, WSACreateEvent());
 603
 604         if(stop_io.event == FALSE) {
 605                 abort();
 606         }
 607
 608         int result;
 609
 610         if(!do_detach || !init_service()) {
 611                 SetConsoleCtrlHandler(console_ctrl_handler, TRUE);
 612                 result = main2(argc, argv);
 613         } else {
 614                 result = 1;
 615         }
 616
 617         if(WSACloseEvent(stop_io.event) == FALSE) {
 618                 abort();
 619         }
 620
 621         io_del(&stop_io);
 622         return result;
 623 }
 624
 625 int main2(int argc, char **argv) {
 626         (void)argc;
 627         (void)argv;
 628 #endif
 629         char *priority = NULL;
 630
 631         if(!detach()) {
 632                 return 1;
 633         }
 634
 635 #ifdef HAVE_MLOCKALL
 636
 637         /* Lock all pages into memory if requested.
 638          * This has to be done after daemon()/fork() so it works for child.
 639          * No need to do that in parent as it's very short-lived. */
 640         if(do_mlock && mlockall(MCL_CURRENT | MCL_FUTURE) != 0) {
 641                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "mlockall",
 642                        strerror(errno));
 643                 return 1;
 644         }
 645
 646 #endif
 647
 648         /* Setup sockets and open device. */
 649
 650         if(!setup_network()) {
 651                 goto end;
 652         }
 653
 654         /* Change process priority */
 655
 656         if(get_config_string(lookup_config(&config_tree, "ProcessPriority"), &priority)) {
 657                 if(!strcasecmp(priority, "Normal")) {
 658                         if(setpriority(NORMAL_PRIORITY_CLASS) != 0) {
 659                                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setpriority", strerror(errno));
 660                                 goto end;
 661                         }
 662                 } else if(!strcasecmp(priority, "Low")) {
 663                         if(setpriority(BELOW_NORMAL_PRIORITY_CLASS) != 0) {
 664                                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setpriority", strerror(errno));
 665                                 goto end;
 666                         }
 667                 } else if(!strcasecmp(priority, "High")) {
 668                         if(setpriority(HIGH_PRIORITY_CLASS) != 0) {
 669                                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setpriority", strerror(errno));
 670                                 goto end;
 671                         }
 672                 } else {
 673                         logger(DEBUG_ALWAYS, LOG_ERR, "Invalid priority `%s`!", priority);
 674                         goto end;
 675                 }
 676         }
 677
 678         /* drop privileges */
 679         if(!drop_privs()) {
 680                 goto end;
 681         }
 682
 683         /* Start main loop. It only exits when tinc is killed. */
 684
 685         logger(DEBUG_ALWAYS, LOG_NOTICE, "Ready");
 686
 687         if(umbilical) { // snip!
 688                 if(write(umbilical, "", 1) != 1) {
 689                         // Pipe full or broken, nothing we can do about it.
 690                 }
 691
 692                 close(umbilical);
 693                 umbilical = 0;
 694         }
 695
 696         try_outgoing_connections();
 697
 698 #ifdef HAVE_WATCHDOG
 699         watchdog_start();
 700 #endif
 701
 702         status = main_loop();
 703
 704 #ifdef HAVE_WATCHDOG
 705         watchdog_stop();
 706 #endif
 707
 708         /* Shutdown properly. */
 709
 710 end:
 711         close_network_connections();
 712
 713         logger(DEBUG_ALWAYS, LOG_NOTICE, "Terminating");
 714
 715         free(priority);
 716
 717         random_exit();
 718
 719         return status;
 720 }