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