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
  59 /* If nonzero, display usage information and exit. */
  60 static bool show_help = false;
  61
  62 /* If nonzero, print the version on standard output and exit.  */
  63 static bool show_version = false;
  64
  65 #ifdef HAVE_MLOCKALL
  66 /* If nonzero, disable swapping for this process. */
  67 static bool do_mlock = false;
  68 #endif
  69
  70 #ifndef HAVE_WINDOWS
  71 /* If nonzero, chroot to netdir after startup. */
  72 static bool do_chroot = false;
  73
  74 /* If !NULL, do setuid to given user after startup */
  75 static const char *switchuser = NULL;
  76 #endif
  77
  78 char **g_argv;                  /* a copy of the cmdline arguments */
  79
  80 static int status = 1;
  81
  82 static struct option const long_options[] = {
  83         {"config", required_argument, NULL, 'c'},
  84         {"net", required_argument, NULL, 'n'},
  85         {"help", no_argument, NULL, 1},
  86         {"version", no_argument, NULL, 2},
  87         {"no-detach", no_argument, NULL, 'D'},
  88         {"debug", optional_argument, NULL, 'd'},
  89         {"bypass-security", no_argument, NULL, 3},
  90         {"mlock", no_argument, NULL, 'L'},
  91         {"chroot", no_argument, NULL, 'R'},
  92         {"user", required_argument, NULL, 'U'},
  93         {"logfile", optional_argument, NULL, 4},
  94         {"syslog", no_argument, NULL, 's'},
  95         {"pidfile", required_argument, NULL, 5},
  96         {"option", required_argument, NULL, 'o'},
  97         {NULL, 0, NULL, 0}
  98 };
  99
 100 #ifdef HAVE_WINDOWS
 101 static struct WSAData wsa_state;
 102 int main2(int argc, char **argv);
 103 #endif
 104
 105 static void usage(bool status) {
 106         if(status)
 107                 fprintf(stderr, "Try `%s --help\' for more information.\n",
 108                         program_name);
 109         else {
 110                 static const char *message =
 111                         "Usage: %s [option]...\n"
 112                         "\n"
 113                         "  -c, --config=DIR              Read configuration options from DIR.\n"
 114                         "  -D, --no-detach               Don't fork and detach.\n"
 115                         "  -d, --debug[=LEVEL]           Increase debug level or set it to LEVEL.\n"
 116                         "  -n, --net=NETNAME             Connect to net NETNAME.\n"
 117 #ifdef HAVE_MLOCKALL
 118                         "  -L, --mlock                   Lock tinc into main memory.\n"
 119 #endif
 120                         "      --logfile[=FILENAME]      Write log entries to a logfile.\n"
 121                         "  -s  --syslog                  Use syslog instead of stderr with --no-detach.\n"
 122                         "      --pidfile=FILENAME        Write PID and control socket cookie to FILENAME.\n"
 123                         "      --bypass-security         Disables meta protocol security, for debugging.\n"
 124                         "  -o, --option[HOST.]KEY=VALUE  Set global/host configuration value.\n"
 125 #ifndef HAVE_WINDOWS
 126                         "  -R, --chroot                  chroot to NET dir at startup.\n"
 127                         "  -U, --user=USER               setuid to given USER at startup.\n"
 128 #endif
 129                         "      --help                    Display this help and exit.\n"
 130                         "      --version                 Output version information and exit.\n"
 131                         "\n"
 132                         "Report bugs to tinc@tinc-vpn.org.\n";
 133
 134                 printf(message, program_name);
 135         }
 136 }
 137
 138 static bool parse_options(int argc, char **argv) {
 139         config_t *cfg;
 140         int r;
 141         int option_index = 0;
 142         int lineno = 0;
 143
 144         while((r = getopt_long(argc, argv, "c:DLd::n:so:RU:", long_options, &option_index)) != EOF) {
 145                 switch(r) {
 146                 case 0:   /* long option */
 147                         break;
 148
 149                 case 'c': /* config file */
 150                         free(confbase);
 151                         confbase = xstrdup(optarg);
 152                         break;
 153
 154                 case 'D': /* no detach */
 155                         do_detach = false;
 156                         break;
 157
 158                 case 'L': /* no detach */
 159 #ifndef HAVE_MLOCKALL
 160                         logger(DEBUG_ALWAYS, LOG_ERR, "The %s option is not supported on this platform.", argv[optind - 1]);
 161                         goto exit_fail;
 162 #else
 163                         do_mlock = true;
 164                         break;
 165 #endif
 166
 167                 case 'd': /* increase debug level */
 168                         if(!optarg && optind < argc && *argv[optind] != '-') {
 169                                 optarg = argv[optind++];
 170                         }
 171
 172                         if(optarg) {
 173                                 debug_level = atoi(optarg);
 174                         } else {
 175                                 debug_level++;
 176                         }
 177
 178                         break;
 179
 180                 case 'n': /* net name given */
 181                         free(netname);
 182                         netname = xstrdup(optarg);
 183                         break;
 184
 185                 case 's': /* syslog */
 186                         use_logfile = false;
 187                         use_syslog = true;
 188                         break;
 189
 190                 case 'o': /* option */
 191                         cfg = parse_config_line(optarg, NULL, ++lineno);
 192
 193                         if(!cfg) {
 194                                 goto exit_fail;
 195                         }
 196
 197                         list_insert_tail(&cmdline_conf, cfg);
 198                         break;
 199
 200 #ifdef HAVE_WINDOWS
 201
 202                 case 'R':
 203                 case 'U':
 204                         logger(DEBUG_ALWAYS, LOG_ERR, "The %s option is not supported on this platform.", argv[optind - 1]);
 205                         goto exit_fail;
 206 #else
 207
 208                 case 'R': /* chroot to NETNAME dir */
 209                         do_chroot = true;
 210                         break;
 211
 212                 case 'U': /* setuid to USER */
 213                         switchuser = optarg;
 214                         break;
 215 #endif
 216
 217                 case 1:   /* show help */
 218                         show_help = true;
 219                         break;
 220
 221                 case 2:   /* show version */
 222                         show_version = true;
 223                         break;
 224
 225                 case 3:   /* bypass security */
 226                         bypass_security = true;
 227                         break;
 228
 229                 case 4:   /* write log entries to a file */
 230                         use_syslog = false;
 231                         use_logfile = true;
 232
 233                         if(!optarg && optind < argc && *argv[optind] != '-') {
 234                                 optarg = argv[optind++];
 235                         }
 236
 237                         if(optarg) {
 238                                 free(logfilename);
 239                                 logfilename = xstrdup(optarg);
 240                         }
 241
 242                         break;
 243
 244                 case 5:   /* open control socket here */
 245                         free(pidfilename);
 246                         pidfilename = xstrdup(optarg);
 247                         break;
 248
 249                 case '?': /* wrong options */
 250                         usage(true);
 251                         goto exit_fail;
 252
 253                 default:
 254                         break;
 255                 }
 256         }
 257
 258         if(optind < argc) {
 259                 fprintf(stderr, "%s: unrecognized argument '%s'\n", argv[0], argv[optind]);
 260                 usage(true);
 261                 goto exit_fail;
 262         }
 263
 264         if(!netname && (netname = getenv("NETNAME"))) {
 265                 netname = xstrdup(netname);
 266         }
 267
 268         /* netname "." is special: a "top-level name" */
 269
 270         if(netname && (!*netname || !strcmp(netname, "."))) {
 271                 free(netname);
 272                 netname = NULL;
 273         }
 274
 275         if(netname && !check_netname(netname, false)) {
 276                 fprintf(stderr, "Invalid character in netname!\n");
 277                 goto exit_fail;
 278         }
 279
 280         if(netname && !check_netname(netname, true)) {
 281                 fprintf(stderr, "Warning: unsafe character in netname!\n");
 282         }
 283
 284         return true;
 285
 286 exit_fail:
 287         free_names();
 288         list_empty_list(&cmdline_conf);
 289         return false;
 290 }
 291
 292 static bool drop_privs(void) {
 293 #ifndef HAVE_WINDOWS
 294         uid_t uid = 0;
 295
 296         if(switchuser) {
 297                 struct passwd *pw = getpwnam(switchuser);
 298
 299                 if(!pw) {
 300                         logger(DEBUG_ALWAYS, LOG_ERR, "unknown user `%s'", switchuser);
 301                         return false;
 302                 }
 303
 304                 uid = pw->pw_uid;
 305
 306                 // The second parameter to initgroups on macOS requires int,
 307                 // but __gid_t is unsigned int. There's not much we can do here.
 308                 if(initgroups(switchuser, pw->pw_gid) != 0 || // NOLINT(bugprone-narrowing-conversions)
 309                                 setgid(pw->pw_gid) != 0) {
 310                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
 311                                "initgroups", strerror(errno));
 312                         return false;
 313                 }
 314
 315 #ifndef __ANDROID__
 316 // Not supported in android NDK
 317                 endgrent();
 318                 endpwent();
 319 #endif
 320         }
 321
 322         if(do_chroot) {
 323                 tzset();        /* for proper timestamps in logs */
 324
 325                 if(chroot(confbase) != 0 || chdir("/") != 0) {
 326                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
 327                                "chroot", strerror(errno));
 328                         return false;
 329                 }
 330
 331                 free(confbase);
 332                 confbase = xstrdup("");
 333         }
 334
 335         if(switchuser)
 336                 if(setuid(uid) != 0) {
 337                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
 338                                "setuid", strerror(errno));
 339                         return false;
 340                 }
 341
 342 #endif
 343         return true;
 344 }
 345
 346 #ifdef HAVE_WINDOWS
 347 # define setpriority(level) !SetPriorityClass(GetCurrentProcess(), (level))
 348
 349 static void stop_handler(void *data, int flags) {
 350         (void)data;
 351         (void)flags;
 352
 353         event_exit();
 354 }
 355
 356 static BOOL WINAPI console_ctrl_handler(DWORD type) {
 357         (void)type;
 358
 359         logger(DEBUG_ALWAYS, LOG_NOTICE, "Got console shutdown request");
 360
 361         if(WSASetEvent(stop_io.event) == FALSE) {
 362                 abort();
 363         }
 364
 365         return TRUE;
 366 }
 367 #else
 368 # define NORMAL_PRIORITY_CLASS 0
 369 # define BELOW_NORMAL_PRIORITY_CLASS 10
 370 # define HIGH_PRIORITY_CLASS -10
 371 # define setpriority(level) (setpriority(PRIO_PROCESS, 0, (level)))
 372 #endif
 373
 374 static void cleanup(void) {
 375         splay_empty_tree(&config_tree);
 376         list_empty_list(&cmdline_conf);
 377         free_names();
 378 }
 379
 380 int main(int argc, char **argv) {
 381         program_name = argv[0];
 382
 383         if(!parse_options(argc, argv)) {
 384                 return 1;
 385         }
 386
 387         if(show_version) {
 388                 static const char *message =
 389                         "%s version %s (built %s %s, protocol %d.%d)\n"
 390                         "Features:"
 391 #ifdef HAVE_OPENSSL
 392                         " openssl"
 393 #endif
 394 #ifdef HAVE_LIBGCRYPT
 395                         " libgcrypt"
 396 #endif
 397 #ifdef HAVE_LZO
 398                         " comp_lzo"
 399 #endif
 400 #ifdef HAVE_ZLIB
 401                         " comp_zlib"
 402 #endif
 403 #ifdef HAVE_LZ4
 404                         " comp_lz4"
 405 #endif
 406 #ifndef DISABLE_LEGACY
 407                         " legacy_protocol"
 408 #endif
 409 #ifdef ENABLE_JUMBOGRAMS
 410                         " jumbograms"
 411 #endif
 412 #ifdef ENABLE_TUNEMU
 413                         " tunemu"
 414 #endif
 415 #ifdef HAVE_MINIUPNPC
 416                         " miniupnpc"
 417 #endif
 418 #ifdef ENABLE_UML
 419                         " uml"
 420 #endif
 421 #ifdef ENABLE_VDE
 422                         " vde"
 423 #endif
 424                         "\n\n"
 425                         "Copyright (C) 1998-2021 Ivo Timmermans, Guus Sliepen and others.\n"
 426                         "See the AUTHORS file for a complete list.\n"
 427                         "\n"
 428                         "tinc comes with ABSOLUTELY NO WARRANTY.  This is free software,\n"
 429                         "and you are welcome to redistribute it under certain conditions;\n"
 430                         "see the file COPYING for details.\n";
 431
 432                 printf(message, PACKAGE, BUILD_VERSION, BUILD_DATE, BUILD_TIME, PROT_MAJOR, PROT_MINOR);
 433                 return 0;
 434         }
 435
 436         if(show_help) {
 437                 usage(false);
 438                 return 0;
 439         }
 440
 441         make_names(true);
 442         atexit(cleanup);
 443
 444         if(chdir(confbase) == -1) {
 445                 logger(DEBUG_ALWAYS, LOG_ERR, "Could not change to configuration directory: %s", strerror(errno));
 446                 return 1;
 447         }
 448
 449 #ifdef HAVE_WINDOWS
 450
 451         if(WSAStartup(MAKEWORD(2, 2), &wsa_state)) {
 452                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "WSAStartup", winerror(GetLastError()));
 453                 return 1;
 454         }
 455
 456 #else
 457         // Check if we got an umbilical fd from the process that started us
 458         char *umbstr = getenv("TINC_UMBILICAL");
 459
 460         if(umbstr) {
 461                 umbilical = atoi(umbstr);
 462
 463                 if(fcntl(umbilical, F_GETFL) < 0) {
 464                         umbilical = 0;
 465                 }
 466
 467 #ifdef FD_CLOEXEC
 468
 469                 if(umbilical) {
 470                         fcntl(umbilical, F_SETFD, FD_CLOEXEC);
 471                 }
 472
 473 #endif
 474         }
 475
 476 #endif
 477
 478         openlogger("tinc", use_logfile ? LOGMODE_FILE : LOGMODE_STDERR);
 479
 480         g_argv = argv;
 481
 482         if(getenv("LISTEN_PID") && atoi(getenv("LISTEN_PID")) == getpid()) {
 483                 do_detach = false;
 484         }
 485
 486 #ifdef HAVE_UNSETENV
 487         unsetenv("LISTEN_PID");
 488 #endif
 489
 490         gettimeofday(&now, NULL);
 491         random_init();
 492         crypto_init();
 493         prng_init();
 494
 495         if(!read_server_config(&config_tree)) {
 496                 return 1;
 497         }
 498
 499         if(debug_level == DEBUG_NOTHING) {
 500                 int level = 0;
 501
 502                 if(get_config_int(lookup_config(&config_tree, "LogLevel"), &level)) {
 503                         debug_level = level;
 504                 }
 505         }
 506
 507 #ifdef HAVE_LZO
 508
 509         if(lzo_init() != LZO_E_OK) {
 510                 logger(DEBUG_ALWAYS, LOG_ERR, "Error initializing LZO compressor!");
 511                 return 1;
 512         }
 513
 514 #endif
 515
 516 #ifdef HAVE_WINDOWS
 517         io_add_event(&stop_io, stop_handler, NULL, WSACreateEvent());
 518
 519         if(stop_io.event == FALSE) {
 520                 abort();
 521         }
 522
 523         int result;
 524
 525         if(!do_detach || !init_service()) {
 526                 SetConsoleCtrlHandler(console_ctrl_handler, TRUE);
 527                 result = main2(argc, argv);
 528         } else {
 529                 result = 1;
 530         }
 531
 532         if(WSACloseEvent(stop_io.event) == FALSE) {
 533                 abort();
 534         }
 535
 536         io_del(&stop_io);
 537         return result;
 538 }
 539
 540 int main2(int argc, char **argv) {
 541         (void)argc;
 542         (void)argv;
 543 #endif
 544         char *priority = NULL;
 545
 546         if(!detach()) {
 547                 return 1;
 548         }
 549
 550 #ifdef HAVE_MLOCKALL
 551
 552         /* Lock all pages into memory if requested.
 553          * This has to be done after daemon()/fork() so it works for child.
 554          * No need to do that in parent as it's very short-lived. */
 555         if(do_mlock && mlockall(MCL_CURRENT | MCL_FUTURE) != 0) {
 556                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "mlockall",
 557                        strerror(errno));
 558                 return 1;
 559         }
 560
 561 #endif
 562
 563         /* Setup sockets and open device. */
 564
 565         if(!setup_network()) {
 566                 goto end;
 567         }
 568
 569         /* Change process priority */
 570
 571         if(get_config_string(lookup_config(&config_tree, "ProcessPriority"), &priority)) {
 572                 if(!strcasecmp(priority, "Normal")) {
 573                         if(setpriority(NORMAL_PRIORITY_CLASS) != 0) {
 574                                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setpriority", strerror(errno));
 575                                 goto end;
 576                         }
 577                 } else if(!strcasecmp(priority, "Low")) {
 578                         if(setpriority(BELOW_NORMAL_PRIORITY_CLASS) != 0) {
 579                                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setpriority", strerror(errno));
 580                                 goto end;
 581                         }
 582                 } else if(!strcasecmp(priority, "High")) {
 583                         if(setpriority(HIGH_PRIORITY_CLASS) != 0) {
 584                                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setpriority", strerror(errno));
 585                                 goto end;
 586                         }
 587                 } else {
 588                         logger(DEBUG_ALWAYS, LOG_ERR, "Invalid priority `%s`!", priority);
 589                         goto end;
 590                 }
 591         }
 592
 593         /* drop privileges */
 594         if(!drop_privs()) {
 595                 goto end;
 596         }
 597
 598         /* Start main loop. It only exits when tinc is killed. */
 599
 600         logger(DEBUG_ALWAYS, LOG_NOTICE, "Ready");
 601
 602         if(umbilical) { // snip!
 603                 if(write(umbilical, "", 1) != 1) {
 604                         // Pipe full or broken, nothing we can do about it.
 605                 }
 606
 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         random_exit();
 625
 626         return status;
 627 }