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                   2000-2021 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_SYS_MMAN_H
  33 #include <sys/mman.h>
  34 #endif
  35
  36 #ifdef HAVE_LZO
  37 #include LZO1X_H
  38 #endif
  39
  40 #ifdef LZ4_H
  41 #include LZ4_H
  42 #endif
  43
  44 #ifndef HAVE_MINGW
  45 #include <pwd.h>
  46 #include <grp.h>
  47 #include <time.h>
  48 #endif
  49
  50 #include "conf.h"
  51 #include "crypto.h"
  52 #include "event.h"
  53 #include "logger.h"
  54 #include "names.h"
  55 #include "net.h"
  56 #include "process.h"
  57 #include "protocol.h"
  58 #include "utils.h"
  59 #include "xalloc.h"
  60 #include "version.h"
  61
  62 /* If nonzero, display usage information and exit. */
  63 static bool show_help = false;
  64
  65 /* If nonzero, print the version on standard output and exit.  */
  66 static bool show_version = false;
  67
  68 /* If nonzero, use null ciphers and skip all key exchanges. */
  69 bool bypass_security = false;
  70
  71 #ifdef HAVE_MLOCKALL
  72 /* If nonzero, disable swapping for this process. */
  73 static bool do_mlock = false;
  74 #endif
  75
  76 #ifndef HAVE_MINGW
  77 /* If nonzero, chroot to netdir after startup. */
  78 static bool do_chroot = false;
  79
  80 /* If !NULL, do setuid to given user after startup */
  81 static const char *switchuser = NULL;
  82 #endif
  83
  84 /* If nonzero, write log entries to a separate file. */
  85 bool use_logfile = false;
  86
  87 /* If nonzero, use syslog instead of stderr in no-detach mode. */
  88 bool use_syslog = false;
  89
  90 char **g_argv;                  /* a copy of the cmdline arguments */
  91
  92 static int status = 1;
  93
  94 static struct option const long_options[] = {
  95         {"config", required_argument, NULL, 'c'},
  96         {"net", required_argument, NULL, 'n'},
  97         {"help", no_argument, NULL, 1},
  98         {"version", no_argument, NULL, 2},
  99         {"no-detach", no_argument, NULL, 'D'},
 100         {"debug", optional_argument, NULL, 'd'},
 101         {"bypass-security", no_argument, NULL, 3},
 102         {"mlock", no_argument, NULL, 'L'},
 103         {"chroot", no_argument, NULL, 'R'},
 104         {"user", required_argument, NULL, 'U'},
 105         {"logfile", optional_argument, NULL, 4},
 106         {"syslog", no_argument, NULL, 's'},
 107         {"pidfile", required_argument, NULL, 5},
 108         {"option", required_argument, NULL, 'o'},
 109         {NULL, 0, NULL, 0}
 110 };
 111
 112 #ifdef HAVE_MINGW
 113 static struct WSAData wsa_state;
 114 int main2(int argc, char **argv);
 115 #endif
 116
 117 static void usage(bool status) {
 118         if(status)
 119                 fprintf(stderr, "Try `%s --help\' for more information.\n",
 120                         program_name);
 121         else {
 122                 printf("Usage: %s [option]...\n\n", program_name);
 123                 printf("  -c, --config=DIR              Read configuration options from DIR.\n"
 124                        "  -D, --no-detach               Don't fork and detach.\n"
 125                        "  -d, --debug[=LEVEL]           Increase debug level or set it to LEVEL.\n"
 126                        "  -n, --net=NETNAME             Connect to net NETNAME.\n"
 127 #ifdef HAVE_MLOCKALL
 128                        "  -L, --mlock                   Lock tinc into main memory.\n"
 129 #endif
 130                        "      --logfile[=FILENAME]      Write log entries to a logfile.\n"
 131                        "  -s  --syslog                  Use syslog instead of stderr with --no-detach.\n"
 132                        "      --pidfile=FILENAME        Write PID and control socket cookie to FILENAME.\n"
 133                        "      --bypass-security         Disables meta protocol security, for debugging.\n"
 134                        "  -o, --option[HOST.]KEY=VALUE  Set global/host configuration value.\n"
 135 #ifndef HAVE_MINGW
 136                        "  -R, --chroot                  chroot to NET dir at startup.\n"
 137                        "  -U, --user=USER               setuid to given USER at startup.\n"
 138 #endif
 139                        "      --help                    Display this help and exit.\n"
 140                        "      --version                 Output version information and exit.\n\n");
 141                 printf("Report bugs to tinc@tinc-vpn.org.\n");
 142         }
 143 }
 144
 145 static bool parse_options(int argc, char **argv) {
 146         config_t *cfg;
 147         int r;
 148         int option_index = 0;
 149         int lineno = 0;
 150
 151         cmdline_conf = list_alloc((list_action_t)free_config);
 152
 153         while((r = getopt_long(argc, argv, "c:DLd::n:so:RU:", long_options, &option_index)) != EOF) {
 154                 switch(r) {
 155                 case 0:   /* long option */
 156                         break;
 157
 158                 case 'c': /* config file */
 159                         free(confbase);
 160                         confbase = xstrdup(optarg);
 161                         break;
 162
 163                 case 'D': /* no detach */
 164                         do_detach = false;
 165                         break;
 166
 167                 case 'L': /* no detach */
 168 #ifndef HAVE_MLOCKALL
 169                         logger(DEBUG_ALWAYS, LOG_ERR, "The %s option is not supported on this platform.", argv[optind - 1]);
 170                         goto exit_fail;
 171 #else
 172                         do_mlock = true;
 173                         break;
 174 #endif
 175
 176                 case 'd': /* increase debug level */
 177                         if(!optarg && optind < argc && *argv[optind] != '-') {
 178                                 optarg = argv[optind++];
 179                         }
 180
 181                         if(optarg) {
 182                                 debug_level = atoi(optarg);
 183                         } else {
 184                                 debug_level++;
 185                         }
 186
 187                         break;
 188
 189                 case 'n': /* net name given */
 190                         free(netname);
 191                         netname = xstrdup(optarg);
 192                         break;
 193
 194                 case 's': /* syslog */
 195                         use_logfile = false;
 196                         use_syslog = true;
 197                         break;
 198
 199                 case 'o': /* option */
 200                         cfg = parse_config_line(optarg, NULL, ++lineno);
 201
 202                         if(!cfg) {
 203                                 goto exit_fail;
 204                         }
 205
 206                         list_insert_tail(cmdline_conf, cfg);
 207                         break;
 208
 209 #ifdef HAVE_MINGW
 210
 211                 case 'R':
 212                 case 'U':
 213                         logger(DEBUG_ALWAYS, LOG_ERR, "The %s option is not supported on this platform.", argv[optind - 1]);
 214                         goto exit_fail;
 215 #else
 216
 217                 case 'R': /* chroot to NETNAME dir */
 218                         do_chroot = true;
 219                         break;
 220
 221                 case 'U': /* setuid to USER */
 222                         switchuser = optarg;
 223                         break;
 224 #endif
 225
 226                 case 1:   /* show help */
 227                         show_help = true;
 228                         break;
 229
 230                 case 2:   /* show version */
 231                         show_version = true;
 232                         break;
 233
 234                 case 3:   /* bypass security */
 235                         bypass_security = true;
 236                         break;
 237
 238                 case 4:   /* write log entries to a file */
 239                         use_syslog = false;
 240                         use_logfile = true;
 241
 242                         if(!optarg && optind < argc && *argv[optind] != '-') {
 243                                 optarg = argv[optind++];
 244                         }
 245
 246                         if(optarg) {
 247                                 free(logfilename);
 248                                 logfilename = xstrdup(optarg);
 249                         }
 250
 251                         break;
 252
 253                 case 5:   /* open control socket here */
 254                         free(pidfilename);
 255                         pidfilename = xstrdup(optarg);
 256                         break;
 257
 258                 case '?': /* wrong options */
 259                         usage(true);
 260                         goto exit_fail;
 261
 262                 default:
 263                         break;
 264                 }
 265         }
 266
 267         if(optind < argc) {
 268                 fprintf(stderr, "%s: unrecognized argument '%s'\n", argv[0], argv[optind]);
 269                 usage(true);
 270                 goto exit_fail;
 271         }
 272
 273         if(!netname && (netname = getenv("NETNAME"))) {
 274                 netname = xstrdup(netname);
 275         }
 276
 277         /* netname "." is special: a "top-level name" */
 278
 279         if(netname && (!*netname || !strcmp(netname, "."))) {
 280                 free(netname);
 281                 netname = NULL;
 282         }
 283
 284         if(netname && !check_netname(netname, false)) {
 285                 fprintf(stderr, "Invalid character in netname!\n");
 286                 goto exit_fail;
 287         }
 288
 289         if(netname && !check_netname(netname, true)) {
 290                 fprintf(stderr, "Warning: unsafe character in netname!\n");
 291         }
 292
 293         return true;
 294
 295 exit_fail:
 296         free_names();
 297         list_delete_list(cmdline_conf);
 298         cmdline_conf = NULL;
 299         return false;
 300 }
 301
 302 static bool drop_privs(void) {
 303 #ifndef HAVE_MINGW
 304         uid_t uid = 0;
 305
 306         if(switchuser) {
 307                 struct passwd *pw = getpwnam(switchuser);
 308
 309                 if(!pw) {
 310                         logger(DEBUG_ALWAYS, LOG_ERR, "unknown user `%s'", switchuser);
 311                         return false;
 312                 }
 313
 314                 uid = pw->pw_uid;
 315
 316                 // The second parameter to initgroups on macOS requires int,
 317                 // but __gid_t is unsigned int. There's not much we can do here.
 318                 if(initgroups(switchuser, pw->pw_gid) != 0 || // NOLINT(bugprone-narrowing-conversions)
 319                                 setgid(pw->pw_gid) != 0) {
 320                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
 321                                "initgroups", strerror(errno));
 322                         return false;
 323                 }
 324
 325 #ifndef __ANDROID__
 326 // Not supported in android NDK
 327                 endgrent();
 328                 endpwent();
 329 #endif
 330         }
 331
 332         if(do_chroot) {
 333                 tzset();        /* for proper timestamps in logs */
 334
 335                 if(chroot(confbase) != 0 || chdir("/") != 0) {
 336                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
 337                                "chroot", strerror(errno));
 338                         return false;
 339                 }
 340
 341                 free(confbase);
 342                 confbase = xstrdup("");
 343         }
 344
 345         if(switchuser)
 346                 if(setuid(uid) != 0) {
 347                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
 348                                "setuid", strerror(errno));
 349                         return false;
 350                 }
 351
 352 #endif
 353         return true;
 354 }
 355
 356 #ifdef HAVE_MINGW
 357 # define setpriority(level) !SetPriorityClass(GetCurrentProcess(), (level))
 358
 359 static void stop_handler(void *data, int flags) {
 360         (void)data;
 361         (void)flags;
 362
 363         event_exit();
 364 }
 365
 366 static BOOL WINAPI console_ctrl_handler(DWORD type) {
 367         (void)type;
 368
 369         logger(DEBUG_ALWAYS, LOG_NOTICE, "Got console shutdown request");
 370
 371         if(WSASetEvent(stop_io.event) == FALSE) {
 372                 abort();
 373         }
 374
 375         return TRUE;
 376 }
 377 #else
 378 # define NORMAL_PRIORITY_CLASS 0
 379 # define BELOW_NORMAL_PRIORITY_CLASS 10
 380 # define HIGH_PRIORITY_CLASS -10
 381 # define setpriority(level) (setpriority(PRIO_PROCESS, 0, (level)))
 382 #endif
 383
 384 static void cleanup() {
 385         if(config_tree) {
 386                 exit_configuration(&config_tree);
 387         }
 388
 389         list_delete_list(cmdline_conf);
 390         free_names();
 391 }
 392
 393 int main(int argc, char **argv) {
 394         program_name = argv[0];
 395
 396         if(!parse_options(argc, argv)) {
 397                 return 1;
 398         }
 399
 400         if(show_version) {
 401                 printf("%s version %s (built %s %s, protocol %d.%d)\n", PACKAGE,
 402                        BUILD_VERSION, BUILD_DATE, BUILD_TIME, PROT_MAJOR, PROT_MINOR);
 403                 printf("Features:"
 404 #ifdef HAVE_OPENSSL
 405                        " openssl"
 406 #endif
 407 #ifdef HAVE_LIBGCRYPT
 408                        " libgcrypt"
 409 #endif
 410 #ifdef HAVE_LZO
 411                        " comp_lzo"
 412 #endif
 413 #ifdef HAVE_ZLIB
 414                        " comp_zlib"
 415 #endif
 416 #ifdef HAVE_LZ4
 417                        " comp_lz4"
 418 #endif
 419 #ifndef DISABLE_LEGACY
 420                        " legacy_protocol"
 421 #endif
 422 #ifdef ENABLE_JUMBOGRAMS
 423                        " jumbograms"
 424 #endif
 425 #ifdef ENABLE_TUNEMU
 426                        " tunemu"
 427 #endif
 428 #ifdef HAVE_MINIUPNPC
 429                        " miniupnpc"
 430 #endif
 431 #ifdef ENABLE_UML
 432                        " uml"
 433 #endif
 434 #ifdef ENABLE_VDE
 435                        " vde"
 436 #endif
 437                        "\n\n");
 438                 printf("Copyright (C) 1998-2021 Ivo Timmermans, Guus Sliepen and others.\n"
 439                        "See the AUTHORS file for a complete list.\n\n"
 440                        "tinc comes with ABSOLUTELY NO WARRANTY.  This is free software,\n"
 441                        "and you are welcome to redistribute it under certain conditions;\n"
 442                        "see the file COPYING for details.\n");
 443
 444                 return 0;
 445         }
 446
 447         if(show_help) {
 448                 usage(false);
 449                 return 0;
 450         }
 451
 452         make_names(true);
 453         atexit(cleanup);
 454
 455         chdir(confbase);
 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         init_configuration(&config_tree);
 499
 500         /* Slllluuuuuuurrrrp! */
 501
 502         gettimeofday(&now, NULL);
 503         srand(now.tv_sec + now.tv_usec);
 504         crypto_init();
 505
 506         if(!read_server_config(config_tree)) {
 507                 return 1;
 508         }
 509
 510         if(debug_level == DEBUG_NOTHING) {
 511                 int level = 0;
 512
 513                 if(get_config_int(lookup_config(config_tree, "LogLevel"), &level)) {
 514                         debug_level = level;
 515                 }
 516         }
 517
 518 #ifdef HAVE_LZO
 519
 520         if(lzo_init() != LZO_E_OK) {
 521                 logger(DEBUG_ALWAYS, LOG_ERR, "Error initializing LZO compressor!");
 522                 return 1;
 523         }
 524
 525 #endif
 526
 527 #ifdef HAVE_MINGW
 528         io_add_event(&stop_io, stop_handler, NULL, WSACreateEvent());
 529
 530         if(stop_io.event == FALSE) {
 531                 abort();
 532         }
 533
 534         int result;
 535
 536         if(!do_detach || !init_service()) {
 537                 SetConsoleCtrlHandler(console_ctrl_handler, TRUE);
 538                 result = main2(argc, argv);
 539         } else {
 540                 result = 1;
 541         }
 542
 543         if(WSACloseEvent(stop_io.event) == FALSE) {
 544                 abort();
 545         }
 546
 547         io_del(&stop_io);
 548         return result;
 549 }
 550
 551 int main2(int argc, char **argv) {
 552         (void)argc;
 553         (void)argv;
 554 #endif
 555         char *priority = NULL;
 556
 557         if(!detach()) {
 558                 return 1;
 559         }
 560
 561 #ifdef HAVE_MLOCKALL
 562
 563         /* Lock all pages into memory if requested.
 564          * This has to be done after daemon()/fork() so it works for child.
 565          * No need to do that in parent as it's very short-lived. */
 566         if(do_mlock && mlockall(MCL_CURRENT | MCL_FUTURE) != 0) {
 567                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "mlockall",
 568                        strerror(errno));
 569                 return 1;
 570         }
 571
 572 #endif
 573
 574         /* Setup sockets and open device. */
 575
 576         if(!setup_network()) {
 577                 goto end;
 578         }
 579
 580         /* Change process priority */
 581
 582         if(get_config_string(lookup_config(config_tree, "ProcessPriority"), &priority)) {
 583                 if(!strcasecmp(priority, "Normal")) {
 584                         if(setpriority(NORMAL_PRIORITY_CLASS) != 0) {
 585                                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setpriority", strerror(errno));
 586                                 goto end;
 587                         }
 588                 } else if(!strcasecmp(priority, "Low")) {
 589                         if(setpriority(BELOW_NORMAL_PRIORITY_CLASS) != 0) {
 590                                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setpriority", strerror(errno));
 591                                 goto end;
 592                         }
 593                 } else if(!strcasecmp(priority, "High")) {
 594                         if(setpriority(HIGH_PRIORITY_CLASS) != 0) {
 595                                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setpriority", strerror(errno));
 596                                 goto end;
 597                         }
 598                 } else {
 599                         logger(DEBUG_ALWAYS, LOG_ERR, "Invalid priority `%s`!", priority);
 600                         goto end;
 601                 }
 602         }
 603
 604         /* drop privileges */
 605         if(!drop_privs()) {
 606                 goto end;
 607         }
 608
 609         /* Start main loop. It only exits when tinc is killed. */
 610
 611         logger(DEBUG_ALWAYS, LOG_NOTICE, "Ready");
 612
 613         if(umbilical) { // snip!
 614                 write(umbilical, "", 1);
 615                 close(umbilical);
 616                 umbilical = 0;
 617         }
 618
 619         try_outgoing_connections();
 620
 621         status = main_loop();
 622
 623         /* Shutdown properly. */
 624
 625 end:
 626         close_network_connections();
 627
 628         logger(DEBUG_ALWAYS, LOG_NOTICE, "Terminating");
 629
 630         free(priority);
 631
 632         crypto_exit();
 633
 634         return status;
 635 }