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