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                 static const char *message =
 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
 157                 printf(message, program_name);
 158         }
 159 }
 160
 161 // Try to resolve path to absolute, return a copy of the argument if this fails.
 162 static char *get_path_arg(char *arg) {
 163         char *result = absolute_path(arg);
 164
 165         if(!result) {
 166                 result = xstrdup(arg);
 167         }
 168
 169         return result;
 170 }
 171
 172 static bool parse_options(int argc, char **argv) {
 173         config_t *cfg;
 174         int r;
 175         int option_index = 0;
 176         int lineno = 0;
 177
 178         while((r = getopt_long(argc, argv, "c:DLd::n:so:RU:", long_options, &option_index)) != EOF) {
 179                 switch((option_t) r) {
 180                 case OPT_LONG_OPTION:
 181                         break;
 182
 183                 case OPT_BAD_OPTION:
 184                         usage(true);
 185                         goto exit_fail;
 186
 187                 case OPT_CONFIG_FILE:
 188                         free(confbase);
 189                         confbase = get_path_arg(optarg);
 190                         break;
 191
 192                 case OPT_NO_DETACH:
 193                         do_detach = false;
 194                         break;
 195
 196                 case OPT_MLOCK: /* lock tincd into RAM */
 197 #ifndef HAVE_MLOCKALL
 198                         logger(DEBUG_ALWAYS, LOG_ERR, "The %s option is not supported on this platform.", argv[optind - 1]);
 199                         goto exit_fail;
 200 #else
 201                         do_mlock = true;
 202                         break;
 203 #endif
 204
 205                 case OPT_DEBUG: /* increase debug level */
 206                         if(!optarg && optind < argc && *argv[optind] != '-') {
 207                                 optarg = argv[optind++];
 208                         }
 209
 210                         if(optarg) {
 211                                 debug_level = atoi(optarg);
 212                         } else {
 213                                 debug_level++;
 214                         }
 215
 216                         break;
 217
 218                 case OPT_NETNAME:
 219                         free(netname);
 220                         netname = xstrdup(optarg);
 221                         break;
 222
 223                 case OPT_SYSLOG:
 224                         use_logfile = false;
 225                         use_syslog = true;
 226                         break;
 227
 228                 case OPT_OPTION:
 229                         cfg = parse_config_line(optarg, NULL, ++lineno);
 230
 231                         if(!cfg) {
 232                                 goto exit_fail;
 233                         }
 234
 235                         list_insert_tail(&cmdline_conf, cfg);
 236                         break;
 237
 238 #ifdef HAVE_WINDOWS
 239
 240                 case OPT_CHANGE_USER:
 241                 case OPT_CHROOT:
 242                         logger(DEBUG_ALWAYS, LOG_ERR, "The %s option is not supported on this platform.", argv[optind - 1]);
 243                         goto exit_fail;
 244 #else
 245
 246                 case OPT_CHROOT:
 247                         do_chroot = true;
 248                         break;
 249
 250                 case OPT_CHANGE_USER:
 251                         switchuser = optarg;
 252                         break;
 253 #endif
 254
 255                 case OPT_HELP:
 256                         show_help = true;
 257                         break;
 258
 259                 case OPT_VERSION:
 260                         show_version = true;
 261                         break;
 262
 263                 case OPT_NO_SECURITY:
 264                         bypass_security = true;
 265                         break;
 266
 267                 case OPT_LOGFILE:
 268                         use_syslog = false;
 269                         use_logfile = true;
 270
 271                         if(!optarg && optind < argc && *argv[optind] != '-') {
 272                                 optarg = argv[optind++];
 273                         }
 274
 275                         if(optarg) {
 276                                 free(logfilename);
 277                                 logfilename = get_path_arg(optarg);
 278                         }
 279
 280                         break;
 281
 282                 case OPT_PIDFILE:
 283                         free(pidfilename);
 284                         pidfilename = get_path_arg(optarg);
 285                         break;
 286
 287                 default:
 288                         break;
 289                 }
 290         }
 291
 292         if(optind < argc) {
 293                 fprintf(stderr, "%s: unrecognized argument '%s'\n", argv[0], argv[optind]);
 294                 usage(true);
 295                 goto exit_fail;
 296         }
 297
 298         if(!netname && (netname = getenv("NETNAME"))) {
 299                 netname = xstrdup(netname);
 300         }
 301
 302         /* netname "." is special: a "top-level name" */
 303
 304         if(netname && (!*netname || !strcmp(netname, "."))) {
 305                 free(netname);
 306                 netname = NULL;
 307         }
 308
 309         if(netname && !check_netname(netname, false)) {
 310                 fprintf(stderr, "Invalid character in netname!\n");
 311                 goto exit_fail;
 312         }
 313
 314         if(netname && !check_netname(netname, true)) {
 315                 fprintf(stderr, "Warning: unsafe character in netname!\n");
 316         }
 317
 318         return true;
 319
 320 exit_fail:
 321         free_names();
 322         list_empty_list(&cmdline_conf);
 323         return false;
 324 }
 325
 326 static bool drop_privs(void) {
 327 #ifndef HAVE_WINDOWS
 328         uid_t uid = 0;
 329
 330         if(switchuser) {
 331                 struct passwd *pw = getpwnam(switchuser);
 332
 333                 if(!pw) {
 334                         logger(DEBUG_ALWAYS, LOG_ERR, "unknown user `%s'", switchuser);
 335                         return false;
 336                 }
 337
 338                 uid = pw->pw_uid;
 339
 340                 // The second parameter to initgroups on macOS requires int,
 341                 // but __gid_t is unsigned int. There's not much we can do here.
 342                 if(initgroups(switchuser, pw->pw_gid) != 0 || // NOLINT(bugprone-narrowing-conversions)
 343                                 setgid(pw->pw_gid) != 0) {
 344                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
 345                                "initgroups", strerror(errno));
 346                         return false;
 347                 }
 348
 349 #ifndef __ANDROID__
 350 // Not supported in android NDK
 351                 endgrent();
 352                 endpwent();
 353 #endif
 354         }
 355
 356         if(do_chroot) {
 357                 tzset();        /* for proper timestamps in logs */
 358
 359                 if(chroot(confbase) != 0 || chdir("/") != 0) {
 360                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
 361                                "chroot", strerror(errno));
 362                         return false;
 363                 }
 364
 365                 free(confbase);
 366                 confbase = xstrdup("");
 367         }
 368
 369         if(switchuser)
 370                 if(setuid(uid) != 0) {
 371                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
 372                                "setuid", strerror(errno));
 373                         return false;
 374                 }
 375
 376 #endif
 377         return true;
 378 }
 379
 380 #ifdef HAVE_WINDOWS
 381 # define setpriority(level) !SetPriorityClass(GetCurrentProcess(), (level))
 382
 383 static void stop_handler(void *data, int flags) {
 384         (void)data;
 385         (void)flags;
 386
 387         event_exit();
 388 }
 389
 390 static BOOL WINAPI console_ctrl_handler(DWORD type) {
 391         (void)type;
 392
 393         logger(DEBUG_ALWAYS, LOG_NOTICE, "Got console shutdown request");
 394
 395         if(WSASetEvent(stop_io.event) == FALSE) {
 396                 abort();
 397         }
 398
 399         return TRUE;
 400 }
 401 #else
 402 # define NORMAL_PRIORITY_CLASS 0
 403 # define BELOW_NORMAL_PRIORITY_CLASS 10
 404 # define HIGH_PRIORITY_CLASS -10
 405 # define setpriority(level) (setpriority(PRIO_PROCESS, 0, (level)))
 406 #endif
 407
 408 static void cleanup(void) {
 409         splay_empty_tree(&config_tree);
 410         list_empty_list(&cmdline_conf);
 411         free_names();
 412 }
 413
 414 int main(int argc, char **argv) {
 415         program_name = argv[0];
 416
 417         if(!parse_options(argc, argv)) {
 418                 return 1;
 419         }
 420
 421         if(show_version) {
 422                 static const char *message =
 423                         "%s version %s (built %s %s, protocol %d.%d)\n"
 424                         "Features:"
 425 #ifdef HAVE_OPENSSL
 426                         " openssl"
 427 #endif
 428 #ifdef HAVE_LIBGCRYPT
 429                         " libgcrypt"
 430 #endif
 431 #ifdef HAVE_LZO
 432                         " comp_lzo"
 433 #endif
 434 #ifdef HAVE_ZLIB
 435                         " comp_zlib"
 436 #endif
 437 #ifdef HAVE_LZ4
 438                         " comp_lz4"
 439 #endif
 440 #ifndef DISABLE_LEGACY
 441                         " legacy_protocol"
 442 #endif
 443 #ifdef ENABLE_JUMBOGRAMS
 444                         " jumbograms"
 445 #endif
 446 #ifdef ENABLE_TUNEMU
 447                         " tunemu"
 448 #endif
 449 #ifdef HAVE_MINIUPNPC
 450                         " miniupnpc"
 451 #endif
 452 #ifdef ENABLE_UML
 453                         " uml"
 454 #endif
 455 #ifdef ENABLE_VDE
 456                         " vde"
 457 #endif
 458                         "\n\n"
 459                         "Copyright (C) 1998-2021 Ivo Timmermans, Guus Sliepen and others.\n"
 460                         "See the AUTHORS file for a complete list.\n"
 461                         "\n"
 462                         "tinc comes with ABSOLUTELY NO WARRANTY.  This is free software,\n"
 463                         "and you are welcome to redistribute it under certain conditions;\n"
 464                         "see the file COPYING for details.\n";
 465
 466                 printf(message, PACKAGE, BUILD_VERSION, BUILD_DATE, BUILD_TIME, PROT_MAJOR, PROT_MINOR);
 467                 return 0;
 468         }
 469
 470         if(show_help) {
 471                 usage(false);
 472                 return 0;
 473         }
 474
 475         make_names(true);
 476         atexit(cleanup);
 477
 478         if(chdir(confbase) == -1) {
 479                 logger(DEBUG_ALWAYS, LOG_ERR, "Could not change to configuration directory: %s", strerror(errno));
 480                 return 1;
 481         }
 482
 483 #ifdef HAVE_WINDOWS
 484
 485         if(WSAStartup(MAKEWORD(2, 2), &wsa_state)) {
 486                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "WSAStartup", winerror(GetLastError()));
 487                 return 1;
 488         }
 489
 490 #else
 491         // Check if we got an umbilical fd from the process that started us
 492         char *umbstr = getenv("TINC_UMBILICAL");
 493
 494         if(umbstr) {
 495                 int colorize = 0;
 496                 sscanf(umbstr, "%d %d", &umbilical, &colorize);
 497                 umbilical_colorize = colorize;
 498
 499                 if(fcntl(umbilical, F_GETFL) < 0) {
 500                         umbilical = 0;
 501                 }
 502
 503 #ifdef FD_CLOEXEC
 504
 505                 if(umbilical) {
 506                         fcntl(umbilical, F_SETFD, FD_CLOEXEC);
 507                 }
 508
 509 #endif
 510         }
 511
 512 #endif
 513
 514         openlogger("tinc", use_logfile ? LOGMODE_FILE : LOGMODE_STDERR);
 515
 516         g_argv = argv;
 517
 518         if(getenv("LISTEN_PID") && atoi(getenv("LISTEN_PID")) == getpid()) {
 519                 do_detach = false;
 520         }
 521
 522 #ifdef HAVE_UNSETENV
 523         unsetenv("LISTEN_PID");
 524 #endif
 525
 526         gettimeofday(&now, NULL);
 527         random_init();
 528         crypto_init();
 529         prng_init();
 530
 531         if(!read_server_config(&config_tree)) {
 532                 return 1;
 533         }
 534
 535         if(debug_level == DEBUG_NOTHING) {
 536                 int level = 0;
 537
 538                 if(get_config_int(lookup_config(&config_tree, "LogLevel"), &level)) {
 539                         debug_level = level;
 540                 }
 541         }
 542
 543 #ifdef HAVE_LZO
 544
 545         if(lzo_init() != LZO_E_OK) {
 546                 logger(DEBUG_ALWAYS, LOG_ERR, "Error initializing LZO compressor!");
 547                 return 1;
 548         }
 549
 550 #endif
 551
 552 #ifdef HAVE_WINDOWS
 553         io_add_event(&stop_io, stop_handler, NULL, WSACreateEvent());
 554
 555         if(stop_io.event == FALSE) {
 556                 abort();
 557         }
 558
 559         int result;
 560
 561         if(!do_detach || !init_service()) {
 562                 SetConsoleCtrlHandler(console_ctrl_handler, TRUE);
 563                 result = main2(argc, argv);
 564         } else {
 565                 result = 1;
 566         }
 567
 568         if(WSACloseEvent(stop_io.event) == FALSE) {
 569                 abort();
 570         }
 571
 572         io_del(&stop_io);
 573         return result;
 574 }
 575
 576 int main2(int argc, char **argv) {
 577         (void)argc;
 578         (void)argv;
 579 #endif
 580         char *priority = NULL;
 581
 582         if(!detach()) {
 583                 return 1;
 584         }
 585
 586 #ifdef HAVE_MLOCKALL
 587
 588         /* Lock all pages into memory if requested.
 589          * This has to be done after daemon()/fork() so it works for child.
 590          * No need to do that in parent as it's very short-lived. */
 591         if(do_mlock && mlockall(MCL_CURRENT | MCL_FUTURE) != 0) {
 592                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "mlockall",
 593                        strerror(errno));
 594                 return 1;
 595         }
 596
 597 #endif
 598
 599         /* Setup sockets and open device. */
 600
 601         if(!setup_network()) {
 602                 goto end;
 603         }
 604
 605         /* Change process priority */
 606
 607         if(get_config_string(lookup_config(&config_tree, "ProcessPriority"), &priority)) {
 608                 if(!strcasecmp(priority, "Normal")) {
 609                         if(setpriority(NORMAL_PRIORITY_CLASS) != 0) {
 610                                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setpriority", strerror(errno));
 611                                 goto end;
 612                         }
 613                 } else if(!strcasecmp(priority, "Low")) {
 614                         if(setpriority(BELOW_NORMAL_PRIORITY_CLASS) != 0) {
 615                                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setpriority", strerror(errno));
 616                                 goto end;
 617                         }
 618                 } else if(!strcasecmp(priority, "High")) {
 619                         if(setpriority(HIGH_PRIORITY_CLASS) != 0) {
 620                                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setpriority", strerror(errno));
 621                                 goto end;
 622                         }
 623                 } else {
 624                         logger(DEBUG_ALWAYS, LOG_ERR, "Invalid priority `%s`!", priority);
 625                         goto end;
 626                 }
 627         }
 628
 629         /* drop privileges */
 630         if(!drop_privs()) {
 631                 goto end;
 632         }
 633
 634         /* Start main loop. It only exits when tinc is killed. */
 635
 636         logger(DEBUG_ALWAYS, LOG_NOTICE, "Ready");
 637
 638         if(umbilical) { // snip!
 639                 if(write(umbilical, "", 1) != 1) {
 640                         // Pipe full or broken, nothing we can do about it.
 641                 }
 642
 643                 close(umbilical);
 644                 umbilical = 0;
 645         }
 646
 647         try_outgoing_connections();
 648
 649         status = main_loop();
 650
 651         /* Shutdown properly. */
 652
 653 end:
 654         close_network_connections();
 655
 656         logger(DEBUG_ALWAYS, LOG_NOTICE, "Terminating");
 657
 658         free(priority);
 659
 660         random_exit();
 661
 662         return status;
 663 }