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_MINGW
  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
  58 /* If nonzero, display usage information and exit. */
  59 static bool show_help = false;
  60
  61 /* If nonzero, print the version on standard output and exit.  */
  62 static bool show_version = false;
  63
  64 /* If nonzero, use null ciphers and skip all key exchanges. */
  65 bool bypass_security = 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_MINGW
  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 /* If nonzero, write log entries to a separate file. */
  81 bool use_logfile = false;
  82
  83 /* If nonzero, use syslog instead of stderr in no-detach mode. */
  84 bool use_syslog = false;
  85
  86 char **g_argv;                  /* a copy of the cmdline arguments */
  87
  88 static int status = 1;
  89
  90 static struct option const long_options[] = {
  91         {"config", required_argument, NULL, 'c'},
  92         {"net", required_argument, NULL, 'n'},
  93         {"help", no_argument, NULL, 1},
  94         {"version", no_argument, NULL, 2},
  95         {"no-detach", no_argument, NULL, 'D'},
  96         {"debug", optional_argument, NULL, 'd'},
  97         {"bypass-security", no_argument, NULL, 3},
  98         {"mlock", no_argument, NULL, 'L'},
  99         {"chroot", no_argument, NULL, 'R'},
 100         {"user", required_argument, NULL, 'U'},
 101         {"logfile", optional_argument, NULL, 4},
 102         {"syslog", no_argument, NULL, 's'},
 103         {"pidfile", required_argument, NULL, 5},
 104         {"option", required_argument, NULL, 'o'},
 105         {NULL, 0, NULL, 0}
 106 };
 107
 108 #ifdef HAVE_MINGW
 109 static struct WSAData wsa_state;
 110 int main2(int argc, char **argv);
 111 #endif
 112
 113 static void usage(bool status) {
 114         if(status)
 115                 fprintf(stderr, "Try `%s --help\' for more information.\n",
 116                         program_name);
 117         else {
 118                 static const char *message =
 119                         "Usage: %s [option]...\n"
 120                         "\n"
 121                         "  -c, --config=DIR              Read configuration options from DIR.\n"
 122                         "  -D, --no-detach               Don't fork and detach.\n"
 123                         "  -d, --debug[=LEVEL]           Increase debug level or set it to LEVEL.\n"
 124                         "  -n, --net=NETNAME             Connect to net NETNAME.\n"
 125 #ifdef HAVE_MLOCKALL
 126                         "  -L, --mlock                   Lock tinc into main memory.\n"
 127 #endif
 128                         "      --logfile[=FILENAME]      Write log entries to a logfile.\n"
 129                         "  -s  --syslog                  Use syslog instead of stderr with --no-detach.\n"
 130                         "      --pidfile=FILENAME        Write PID and control socket cookie to FILENAME.\n"
 131                         "      --bypass-security         Disables meta protocol security, for debugging.\n"
 132                         "  -o, --option[HOST.]KEY=VALUE  Set global/host configuration value.\n"
 133 #ifndef HAVE_MINGW
 134                         "  -R, --chroot                  chroot to NET dir at startup.\n"
 135                         "  -U, --user=USER               setuid to given USER at startup.\n"
 136 #endif
 137                         "      --help                    Display this help and exit.\n"
 138                         "      --version                 Output version information and exit.\n"
 139                         "\n"
 140                         "Report bugs to tinc@tinc-vpn.org.\n";
 141
 142                 printf(message, program_name);
 143         }
 144 }
 145
 146 static bool parse_options(int argc, char **argv) {
 147         config_t *cfg;
 148         int r;
 149         int option_index = 0;
 150         int lineno = 0;
 151
 152         while((r = getopt_long(argc, argv, "c:DLd::n:so:RU:", long_options, &option_index)) != EOF) {
 153                 switch(r) {
 154                 case 0:   /* long option */
 155                         break;
 156
 157                 case 'c': /* config file */
 158                         free(confbase);
 159                         confbase = xstrdup(optarg);
 160                         break;
 161
 162                 case 'D': /* no detach */
 163                         do_detach = false;
 164                         break;
 165
 166                 case 'L': /* no detach */
 167 #ifndef HAVE_MLOCKALL
 168                         logger(DEBUG_ALWAYS, LOG_ERR, "The %s option is not supported on this platform.", argv[optind - 1]);
 169                         goto exit_fail;
 170 #else
 171                         do_mlock = true;
 172                         break;
 173 #endif
 174
 175                 case 'd': /* increase debug level */
 176                         if(!optarg && optind < argc && *argv[optind] != '-') {
 177                                 optarg = argv[optind++];
 178                         }
 179
 180                         if(optarg) {
 181                                 debug_level = atoi(optarg);
 182                         } else {
 183                                 debug_level++;
 184                         }
 185
 186                         break;
 187
 188                 case 'n': /* net name given */
 189                         free(netname);
 190                         netname = xstrdup(optarg);
 191                         break;
 192
 193                 case 's': /* syslog */
 194                         use_logfile = false;
 195                         use_syslog = true;
 196                         break;
 197
 198                 case 'o': /* option */
 199                         cfg = parse_config_line(optarg, NULL, ++lineno);
 200
 201                         if(!cfg) {
 202                                 goto exit_fail;
 203                         }
 204
 205                         list_insert_tail(&cmdline_conf, cfg);
 206                         break;
 207
 208 #ifdef HAVE_MINGW
 209
 210                 case 'R':
 211                 case 'U':
 212                         logger(DEBUG_ALWAYS, LOG_ERR, "The %s option is not supported on this platform.", argv[optind - 1]);
 213                         goto exit_fail;
 214 #else
 215
 216                 case 'R': /* chroot to NETNAME dir */
 217                         do_chroot = true;
 218                         break;
 219
 220                 case 'U': /* setuid to USER */
 221                         switchuser = optarg;
 222                         break;
 223 #endif
 224
 225                 case 1:   /* show help */
 226                         show_help = true;
 227                         break;
 228
 229                 case 2:   /* show version */
 230                         show_version = true;
 231                         break;
 232
 233                 case 3:   /* bypass security */
 234                         bypass_security = true;
 235                         break;
 236
 237                 case 4:   /* write log entries to a file */
 238                         use_syslog = false;
 239                         use_logfile = true;
 240
 241                         if(!optarg && optind < argc && *argv[optind] != '-') {
 242                                 optarg = argv[optind++];
 243                         }
 244
 245                         if(optarg) {
 246                                 free(logfilename);
 247                                 logfilename = xstrdup(optarg);
 248                         }
 249
 250                         break;
 251
 252                 case 5:   /* open control socket here */
 253                         free(pidfilename);
 254                         pidfilename = xstrdup(optarg);
 255                         break;
 256
 257                 case '?': /* wrong options */
 258                         usage(true);
 259                         goto exit_fail;
 260
 261                 default:
 262                         break;
 263                 }
 264         }
 265
 266         if(optind < argc) {
 267                 fprintf(stderr, "%s: unrecognized argument '%s'\n", argv[0], argv[optind]);
 268                 usage(true);
 269                 goto exit_fail;
 270         }
 271
 272         if(!netname && (netname = getenv("NETNAME"))) {
 273                 netname = xstrdup(netname);
 274         }
 275
 276         /* netname "." is special: a "top-level name" */
 277
 278         if(netname && (!*netname || !strcmp(netname, "."))) {
 279                 free(netname);
 280                 netname = NULL;
 281         }
 282
 283         if(netname && !check_netname(netname, false)) {
 284                 fprintf(stderr, "Invalid character in netname!\n");
 285                 goto exit_fail;
 286         }
 287
 288         if(netname && !check_netname(netname, true)) {
 289                 fprintf(stderr, "Warning: unsafe character in netname!\n");
 290         }
 291
 292         return true;
 293
 294 exit_fail:
 295         free_names();
 296         list_empty_list(&cmdline_conf);
 297         return false;
 298 }
 299
 300 static bool drop_privs(void) {
 301 #ifndef HAVE_MINGW
 302         uid_t uid = 0;
 303
 304         if(switchuser) {
 305                 struct passwd *pw = getpwnam(switchuser);
 306
 307                 if(!pw) {
 308                         logger(DEBUG_ALWAYS, LOG_ERR, "unknown user `%s'", switchuser);
 309                         return false;
 310                 }
 311
 312                 uid = pw->pw_uid;
 313
 314                 // The second parameter to initgroups on macOS requires int,
 315                 // but __gid_t is unsigned int. There's not much we can do here.
 316                 if(initgroups(switchuser, pw->pw_gid) != 0 || // NOLINT(bugprone-narrowing-conversions)
 317                                 setgid(pw->pw_gid) != 0) {
 318                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
 319                                "initgroups", strerror(errno));
 320                         return false;
 321                 }
 322
 323 #ifndef __ANDROID__
 324 // Not supported in android NDK
 325                 endgrent();
 326                 endpwent();
 327 #endif
 328         }
 329
 330         if(do_chroot) {
 331                 tzset();        /* for proper timestamps in logs */
 332
 333                 if(chroot(confbase) != 0 || chdir("/") != 0) {
 334                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
 335                                "chroot", strerror(errno));
 336                         return false;
 337                 }
 338
 339                 free(confbase);
 340                 confbase = xstrdup("");
 341         }
 342
 343         if(switchuser)
 344                 if(setuid(uid) != 0) {
 345                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
 346                                "setuid", strerror(errno));
 347                         return false;
 348                 }
 349
 350 #endif
 351         return true;
 352 }
 353
 354 #ifdef HAVE_MINGW
 355 # define setpriority(level) !SetPriorityClass(GetCurrentProcess(), (level))
 356
 357 static void stop_handler(void *data, int flags) {
 358         (void)data;
 359         (void)flags;
 360
 361         event_exit();
 362 }
 363
 364 static BOOL WINAPI console_ctrl_handler(DWORD type) {
 365         (void)type;
 366
 367         logger(DEBUG_ALWAYS, LOG_NOTICE, "Got console shutdown request");
 368
 369         if(WSASetEvent(stop_io.event) == FALSE) {
 370                 abort();
 371         }
 372
 373         return TRUE;
 374 }
 375 #else
 376 # define NORMAL_PRIORITY_CLASS 0
 377 # define BELOW_NORMAL_PRIORITY_CLASS 10
 378 # define HIGH_PRIORITY_CLASS -10
 379 # define setpriority(level) (setpriority(PRIO_PROCESS, 0, (level)))
 380 #endif
 381
 382 static void cleanup(void) {
 383         splay_empty_tree(&config_tree);
 384         list_empty_list(&cmdline_conf);
 385         free_names();
 386 }
 387
 388 int main(int argc, char **argv) {
 389         program_name = argv[0];
 390
 391         if(!parse_options(argc, argv)) {
 392                 return 1;
 393         }
 394
 395         if(show_version) {
 396                 static const char *message =
 397                         "%s version %s (built %s %s, protocol %d.%d)\n"
 398                         "Features:"
 399 #ifdef HAVE_OPENSSL
 400                         " openssl"
 401 #endif
 402 #ifdef HAVE_LIBGCRYPT
 403                         " libgcrypt"
 404 #endif
 405 #ifdef HAVE_LZO
 406                         " comp_lzo"
 407 #endif
 408 #ifdef HAVE_ZLIB
 409                         " comp_zlib"
 410 #endif
 411 #ifdef HAVE_LZ4
 412                         " comp_lz4"
 413 #endif
 414 #ifndef DISABLE_LEGACY
 415                         " legacy_protocol"
 416 #endif
 417 #ifdef ENABLE_JUMBOGRAMS
 418                         " jumbograms"
 419 #endif
 420 #ifdef ENABLE_TUNEMU
 421                         " tunemu"
 422 #endif
 423 #ifdef HAVE_MINIUPNPC
 424                         " miniupnpc"
 425 #endif
 426 #ifdef ENABLE_UML
 427                         " uml"
 428 #endif
 429 #ifdef ENABLE_VDE
 430                         " vde"
 431 #endif
 432                         "\n\n"
 433                         "Copyright (C) 1998-2021 Ivo Timmermans, Guus Sliepen and others.\n"
 434                         "See the AUTHORS file for a complete list.\n"
 435                         "\n"
 436                         "tinc comes with ABSOLUTELY NO WARRANTY.  This is free software,\n"
 437                         "and you are welcome to redistribute it under certain conditions;\n"
 438                         "see the file COPYING for details.\n";
 439
 440                 printf(message, PACKAGE, BUILD_VERSION, BUILD_DATE, BUILD_TIME, PROT_MAJOR, PROT_MINOR);
 441                 return 0;
 442         }
 443
 444         if(show_help) {
 445                 usage(false);
 446                 return 0;
 447         }
 448
 449         make_names(true);
 450         atexit(cleanup);
 451
 452         if(chdir(confbase) == -1) {
 453                 logger(DEBUG_ALWAYS, LOG_ERR, "Could not change to configuration directory: %s", strerror(errno));
 454                 return 1;
 455         }
 456
 457 #ifdef HAVE_MINGW
 458
 459         if(WSAStartup(MAKEWORD(2, 2), &wsa_state)) {
 460                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "WSAStartup", winerror(GetLastError()));
 461                 return 1;
 462         }
 463
 464 #else
 465         // Check if we got an umbilical fd from the process that started us
 466         char *umbstr = getenv("TINC_UMBILICAL");
 467
 468         if(umbstr) {
 469                 umbilical = atoi(umbstr);
 470
 471                 if(fcntl(umbilical, F_GETFL) < 0) {
 472                         umbilical = 0;
 473                 }
 474
 475 #ifdef FD_CLOEXEC
 476
 477                 if(umbilical) {
 478                         fcntl(umbilical, F_SETFD, FD_CLOEXEC);
 479                 }
 480
 481 #endif
 482         }
 483
 484 #endif
 485
 486         openlogger("tinc", use_logfile ? LOGMODE_FILE : LOGMODE_STDERR);
 487
 488         g_argv = argv;
 489
 490         if(getenv("LISTEN_PID") && atoi(getenv("LISTEN_PID")) == getpid()) {
 491                 do_detach = false;
 492         }
 493
 494 #ifdef HAVE_UNSETENV
 495         unsetenv("LISTEN_PID");
 496 #endif
 497
 498         gettimeofday(&now, NULL);
 499         crypto_init();
 500         prng_init();
 501
 502         if(!read_server_config(&config_tree)) {
 503                 return 1;
 504         }
 505
 506         if(debug_level == DEBUG_NOTHING) {
 507                 int level = 0;
 508
 509                 if(get_config_int(lookup_config(&config_tree, "LogLevel"), &level)) {
 510                         debug_level = level;
 511                 }
 512         }
 513
 514 #ifdef HAVE_LZO
 515
 516         if(lzo_init() != LZO_E_OK) {
 517                 logger(DEBUG_ALWAYS, LOG_ERR, "Error initializing LZO compressor!");
 518                 return 1;
 519         }
 520
 521 #endif
 522
 523 #ifdef HAVE_MINGW
 524         io_add_event(&stop_io, stop_handler, NULL, WSACreateEvent());
 525
 526         if(stop_io.event == FALSE) {
 527                 abort();
 528         }
 529
 530         int result;
 531
 532         if(!do_detach || !init_service()) {
 533                 SetConsoleCtrlHandler(console_ctrl_handler, TRUE);
 534                 result = main2(argc, argv);
 535         } else {
 536                 result = 1;
 537         }
 538
 539         if(WSACloseEvent(stop_io.event) == FALSE) {
 540                 abort();
 541         }
 542
 543         io_del(&stop_io);
 544         return result;
 545 }
 546
 547 int main2(int argc, char **argv) {
 548         (void)argc;
 549         (void)argv;
 550 #endif
 551         char *priority = NULL;
 552
 553         if(!detach()) {
 554                 return 1;
 555         }
 556
 557 #ifdef HAVE_MLOCKALL
 558
 559         /* Lock all pages into memory if requested.
 560          * This has to be done after daemon()/fork() so it works for child.
 561          * No need to do that in parent as it's very short-lived. */
 562         if(do_mlock && mlockall(MCL_CURRENT | MCL_FUTURE) != 0) {
 563                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "mlockall",
 564                        strerror(errno));
 565                 return 1;
 566         }
 567
 568 #endif
 569
 570         /* Setup sockets and open device. */
 571
 572         if(!setup_network()) {
 573                 goto end;
 574         }
 575
 576         /* Change process priority */
 577
 578         if(get_config_string(lookup_config(&config_tree, "ProcessPriority"), &priority)) {
 579                 if(!strcasecmp(priority, "Normal")) {
 580                         if(setpriority(NORMAL_PRIORITY_CLASS) != 0) {
 581                                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setpriority", strerror(errno));
 582                                 goto end;
 583                         }
 584                 } else if(!strcasecmp(priority, "Low")) {
 585                         if(setpriority(BELOW_NORMAL_PRIORITY_CLASS) != 0) {
 586                                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setpriority", strerror(errno));
 587                                 goto end;
 588                         }
 589                 } else if(!strcasecmp(priority, "High")) {
 590                         if(setpriority(HIGH_PRIORITY_CLASS) != 0) {
 591                                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setpriority", strerror(errno));
 592                                 goto end;
 593                         }
 594                 } else {
 595                         logger(DEBUG_ALWAYS, LOG_ERR, "Invalid priority `%s`!", priority);
 596                         goto end;
 597                 }
 598         }
 599
 600         /* drop privileges */
 601         if(!drop_privs()) {
 602                 goto end;
 603         }
 604
 605         /* Start main loop. It only exits when tinc is killed. */
 606
 607         logger(DEBUG_ALWAYS, LOG_NOTICE, "Ready");
 608
 609         if(umbilical) { // snip!
 610                 if(write(umbilical, "", 1) != 1) {
 611                         // Pipe full or broken, nothing we can do about it.
 612                 }
 613
 614                 close(umbilical);
 615                 umbilical = 0;
 616         }
 617
 618         try_outgoing_connections();
 619
 620         status = main_loop();
 621
 622         /* Shutdown properly. */
 623
 624 end:
 625         close_network_connections();
 626
 627         logger(DEBUG_ALWAYS, LOG_NOTICE, "Terminating");
 628
 629         free(priority);
 630
 631         crypto_exit();
 632
 633         return status;
 634 }