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_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                 static const char *message =
 123                         "Usage: %s [option]...\n"
 124                         "\n"
 125                         "  -c, --config=DIR              Read configuration options from DIR.\n"
 126                         "  -D, --no-detach               Don't fork and detach.\n"
 127                         "  -d, --debug[=LEVEL]           Increase debug level or set it to LEVEL.\n"
 128                         "  -n, --net=NETNAME             Connect to net NETNAME.\n"
 129 #ifdef HAVE_MLOCKALL
 130                         "  -L, --mlock                   Lock tinc into main memory.\n"
 131 #endif
 132                         "      --logfile[=FILENAME]      Write log entries to a logfile.\n"
 133                         "  -s  --syslog                  Use syslog instead of stderr with --no-detach.\n"
 134                         "      --pidfile=FILENAME        Write PID and control socket cookie to FILENAME.\n"
 135                         "      --bypass-security         Disables meta protocol security, for debugging.\n"
 136                         "  -o, --option[HOST.]KEY=VALUE  Set global/host configuration value.\n"
 137 #ifndef HAVE_MINGW
 138                         "  -R, --chroot                  chroot to NET dir at startup.\n"
 139                         "  -U, --user=USER               setuid to given USER at startup.\n"
 140 #endif
 141                         "      --help                    Display this help and exit.\n"
 142                         "      --version                 Output version information and exit.\n"
 143                         "\n"
 144                         "Report bugs to tinc@tinc-vpn.org.\n";
 145
 146                 printf(message, program_name);
 147         }
 148 }
 149
 150 static bool parse_options(int argc, char **argv) {
 151         config_t *cfg;
 152         int r;
 153         int option_index = 0;
 154         int lineno = 0;
 155
 156         while((r = getopt_long(argc, argv, "c:DLd::n:so:RU:", long_options, &option_index)) != EOF) {
 157                 switch(r) {
 158                 case 0:   /* long option */
 159                         break;
 160
 161                 case 'c': /* config file */
 162                         free(confbase);
 163                         confbase = xstrdup(optarg);
 164                         break;
 165
 166                 case 'D': /* no detach */
 167                         do_detach = false;
 168                         break;
 169
 170                 case 'L': /* no detach */
 171 #ifndef HAVE_MLOCKALL
 172                         logger(DEBUG_ALWAYS, LOG_ERR, "The %s option is not supported on this platform.", argv[optind - 1]);
 173                         goto exit_fail;
 174 #else
 175                         do_mlock = true;
 176                         break;
 177 #endif
 178
 179                 case 'd': /* increase debug level */
 180                         if(!optarg && optind < argc && *argv[optind] != '-') {
 181                                 optarg = argv[optind++];
 182                         }
 183
 184                         if(optarg) {
 185                                 debug_level = atoi(optarg);
 186                         } else {
 187                                 debug_level++;
 188                         }
 189
 190                         break;
 191
 192                 case 'n': /* net name given */
 193                         free(netname);
 194                         netname = xstrdup(optarg);
 195                         break;
 196
 197                 case 's': /* syslog */
 198                         use_logfile = false;
 199                         use_syslog = true;
 200                         break;
 201
 202                 case 'o': /* option */
 203                         cfg = parse_config_line(optarg, NULL, ++lineno);
 204
 205                         if(!cfg) {
 206                                 goto exit_fail;
 207                         }
 208
 209                         list_insert_tail(&cmdline_conf, cfg);
 210                         break;
 211
 212 #ifdef HAVE_MINGW
 213
 214                 case 'R':
 215                 case 'U':
 216                         logger(DEBUG_ALWAYS, LOG_ERR, "The %s option is not supported on this platform.", argv[optind - 1]);
 217                         goto exit_fail;
 218 #else
 219
 220                 case 'R': /* chroot to NETNAME dir */
 221                         do_chroot = true;
 222                         break;
 223
 224                 case 'U': /* setuid to USER */
 225                         switchuser = optarg;
 226                         break;
 227 #endif
 228
 229                 case 1:   /* show help */
 230                         show_help = true;
 231                         break;
 232
 233                 case 2:   /* show version */
 234                         show_version = true;
 235                         break;
 236
 237                 case 3:   /* bypass security */
 238                         bypass_security = true;
 239                         break;
 240
 241                 case 4:   /* write log entries to a file */
 242                         use_syslog = false;
 243                         use_logfile = true;
 244
 245                         if(!optarg && optind < argc && *argv[optind] != '-') {
 246                                 optarg = argv[optind++];
 247                         }
 248
 249                         if(optarg) {
 250                                 free(logfilename);
 251                                 logfilename = xstrdup(optarg);
 252                         }
 253
 254                         break;
 255
 256                 case 5:   /* open control socket here */
 257                         free(pidfilename);
 258                         pidfilename = xstrdup(optarg);
 259                         break;
 260
 261                 case '?': /* wrong options */
 262                         usage(true);
 263                         goto exit_fail;
 264
 265                 default:
 266                         break;
 267                 }
 268         }
 269
 270         if(optind < argc) {
 271                 fprintf(stderr, "%s: unrecognized argument '%s'\n", argv[0], argv[optind]);
 272                 usage(true);
 273                 goto exit_fail;
 274         }
 275
 276         if(!netname && (netname = getenv("NETNAME"))) {
 277                 netname = xstrdup(netname);
 278         }
 279
 280         /* netname "." is special: a "top-level name" */
 281
 282         if(netname && (!*netname || !strcmp(netname, "."))) {
 283                 free(netname);
 284                 netname = NULL;
 285         }
 286
 287         if(netname && !check_netname(netname, false)) {
 288                 fprintf(stderr, "Invalid character in netname!\n");
 289                 goto exit_fail;
 290         }
 291
 292         if(netname && !check_netname(netname, true)) {
 293                 fprintf(stderr, "Warning: unsafe character in netname!\n");
 294         }
 295
 296         return true;
 297
 298 exit_fail:
 299         free_names();
 300         list_empty_list(&cmdline_conf);
 301         return false;
 302 }
 303
 304 static bool drop_privs(void) {
 305 #ifndef HAVE_MINGW
 306         uid_t uid = 0;
 307
 308         if(switchuser) {
 309                 struct passwd *pw = getpwnam(switchuser);
 310
 311                 if(!pw) {
 312                         logger(DEBUG_ALWAYS, LOG_ERR, "unknown user `%s'", switchuser);
 313                         return false;
 314                 }
 315
 316                 uid = pw->pw_uid;
 317
 318                 // The second parameter to initgroups on macOS requires int,
 319                 // but __gid_t is unsigned int. There's not much we can do here.
 320                 if(initgroups(switchuser, pw->pw_gid) != 0 || // NOLINT(bugprone-narrowing-conversions)
 321                                 setgid(pw->pw_gid) != 0) {
 322                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
 323                                "initgroups", strerror(errno));
 324                         return false;
 325                 }
 326
 327 #ifndef __ANDROID__
 328 // Not supported in android NDK
 329                 endgrent();
 330                 endpwent();
 331 #endif
 332         }
 333
 334         if(do_chroot) {
 335                 tzset();        /* for proper timestamps in logs */
 336
 337                 if(chroot(confbase) != 0 || chdir("/") != 0) {
 338                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
 339                                "chroot", strerror(errno));
 340                         return false;
 341                 }
 342
 343                 free(confbase);
 344                 confbase = xstrdup("");
 345         }
 346
 347         if(switchuser)
 348                 if(setuid(uid) != 0) {
 349                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
 350                                "setuid", strerror(errno));
 351                         return false;
 352                 }
 353
 354 #endif
 355         return true;
 356 }
 357
 358 #ifdef HAVE_MINGW
 359 # define setpriority(level) !SetPriorityClass(GetCurrentProcess(), (level))
 360
 361 static void stop_handler(void *data, int flags) {
 362         (void)data;
 363         (void)flags;
 364
 365         event_exit();
 366 }
 367
 368 static BOOL WINAPI console_ctrl_handler(DWORD type) {
 369         (void)type;
 370
 371         logger(DEBUG_ALWAYS, LOG_NOTICE, "Got console shutdown request");
 372
 373         if(WSASetEvent(stop_io.event) == FALSE) {
 374                 abort();
 375         }
 376
 377         return TRUE;
 378 }
 379 #else
 380 # define NORMAL_PRIORITY_CLASS 0
 381 # define BELOW_NORMAL_PRIORITY_CLASS 10
 382 # define HIGH_PRIORITY_CLASS -10
 383 # define setpriority(level) (setpriority(PRIO_PROCESS, 0, (level)))
 384 #endif
 385
 386 static void cleanup(void) {
 387         splay_empty_tree(&config_tree);
 388         list_empty_list(&cmdline_conf);
 389         free_names();
 390 }
 391
 392 int main(int argc, char **argv) {
 393         program_name = argv[0];
 394
 395         if(!parse_options(argc, argv)) {
 396                 return 1;
 397         }
 398
 399         if(show_version) {
 400                 static const char *message =
 401                         "%s version %s (built %s %s, protocol %d.%d)\n"
 402                         "Features:"
 403 #ifdef HAVE_OPENSSL
 404                         " openssl"
 405 #endif
 406 #ifdef HAVE_LIBGCRYPT
 407                         " libgcrypt"
 408 #endif
 409 #ifdef HAVE_LZO
 410                         " comp_lzo"
 411 #endif
 412 #ifdef HAVE_ZLIB
 413                         " comp_zlib"
 414 #endif
 415 #ifdef HAVE_LZ4
 416                         " comp_lz4"
 417 #endif
 418 #ifndef DISABLE_LEGACY
 419                         " legacy_protocol"
 420 #endif
 421 #ifdef ENABLE_JUMBOGRAMS
 422                         " jumbograms"
 423 #endif
 424 #ifdef ENABLE_TUNEMU
 425                         " tunemu"
 426 #endif
 427 #ifdef HAVE_MINIUPNPC
 428                         " miniupnpc"
 429 #endif
 430 #ifdef ENABLE_UML
 431                         " uml"
 432 #endif
 433 #ifdef ENABLE_VDE
 434                         " vde"
 435 #endif
 436                         "\n\n"
 437                         "Copyright (C) 1998-2021 Ivo Timmermans, Guus Sliepen and others.\n"
 438                         "See the AUTHORS file for a complete list.\n"
 439                         "\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                 printf(message, PACKAGE, BUILD_VERSION, BUILD_DATE, BUILD_TIME, PROT_MAJOR, PROT_MINOR);
 445                 return 0;
 446         }
 447
 448         if(show_help) {
 449                 usage(false);
 450                 return 0;
 451         }
 452
 453         make_names(true);
 454         atexit(cleanup);
 455
 456         if(chdir(confbase) == -1) {
 457                 logger(DEBUG_ALWAYS, LOG_ERR, "Could not change to configuration directory: %s", strerror(errno));
 458                 return 1;
 459         }
 460
 461 #ifdef HAVE_MINGW
 462
 463         if(WSAStartup(MAKEWORD(2, 2), &wsa_state)) {
 464                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "WSAStartup", winerror(GetLastError()));
 465                 return 1;
 466         }
 467
 468 #else
 469         // Check if we got an umbilical fd from the process that started us
 470         char *umbstr = getenv("TINC_UMBILICAL");
 471
 472         if(umbstr) {
 473                 umbilical = atoi(umbstr);
 474
 475                 if(fcntl(umbilical, F_GETFL) < 0) {
 476                         umbilical = 0;
 477                 }
 478
 479 #ifdef FD_CLOEXEC
 480
 481                 if(umbilical) {
 482                         fcntl(umbilical, F_SETFD, FD_CLOEXEC);
 483                 }
 484
 485 #endif
 486         }
 487
 488 #endif
 489
 490         openlogger("tinc", use_logfile ? LOGMODE_FILE : LOGMODE_STDERR);
 491
 492         g_argv = argv;
 493
 494         if(getenv("LISTEN_PID") && atoi(getenv("LISTEN_PID")) == getpid()) {
 495                 do_detach = false;
 496         }
 497
 498 #ifdef HAVE_UNSETENV
 499         unsetenv("LISTEN_PID");
 500 #endif
 501
 502         gettimeofday(&now, NULL);
 503         crypto_init();
 504         prng_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                 if(write(umbilical, "", 1) != 1) {
 615                         // Pipe full or broken, nothing we can do about it.
 616                 }
 617
 618                 close(umbilical);
 619                 umbilical = 0;
 620         }
 621
 622         try_outgoing_connections();
 623
 624         status = main_loop();
 625
 626         /* Shutdown properly. */
 627
 628 end:
 629         close_network_connections();
 630
 631         logger(DEBUG_ALWAYS, LOG_NOTICE, "Terminating");
 632
 633         free(priority);
 634
 635         crypto_exit();
 636
 637         return status;
 638 }