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         cmdline_conf = list_alloc((list_action_t)free_config);
 152
 153         while((r = getopt_long(argc, argv, "c:DLd::n:so:RU:", long_options, &option_index)) != EOF) {
 154                 switch(r) {
 155                 case 0:   /* long option */
 156                         break;
 157
 158                 case 'c': /* config file */
 159                         free(confbase);
 160                         confbase = xstrdup(optarg);
 161                         break;
 162
 163                 case 'D': /* no detach */
 164                         do_detach = false;
 165                         break;
 166
 167                 case 'L': /* no detach */
 168 #ifndef HAVE_MLOCKALL
 169                         logger(DEBUG_ALWAYS, LOG_ERR, "The %s option is not supported on this platform.", argv[optind - 1]);
 170                         goto exit_fail;
 171 #else
 172                         do_mlock = true;
 173                         break;
 174 #endif
 175
 176                 case 'd': /* increase debug level */
 177                         if(!optarg && optind < argc && *argv[optind] != '-') {
 178                                 optarg = argv[optind++];
 179                         }
 180
 181                         if(optarg) {
 182                                 debug_level = atoi(optarg);
 183                         } else {
 184                                 debug_level++;
 185                         }
 186
 187                         break;
 188
 189                 case 'n': /* net name given */
 190                         free(netname);
 191                         netname = xstrdup(optarg);
 192                         break;
 193
 194                 case 's': /* syslog */
 195                         use_logfile = false;
 196                         use_syslog = true;
 197                         break;
 198
 199                 case 'o': /* option */
 200                         cfg = parse_config_line(optarg, NULL, ++lineno);
 201
 202                         if(!cfg) {
 203                                 goto exit_fail;
 204                         }
 205
 206                         list_insert_tail(cmdline_conf, cfg);
 207                         break;
 208
 209 #ifdef HAVE_MINGW
 210
 211                 case 'R':
 212                 case 'U':
 213                         logger(DEBUG_ALWAYS, LOG_ERR, "The %s option is not supported on this platform.", argv[optind - 1]);
 214                         goto exit_fail;
 215 #else
 216
 217                 case 'R': /* chroot to NETNAME dir */
 218                         do_chroot = true;
 219                         break;
 220
 221                 case 'U': /* setuid to USER */
 222                         switchuser = optarg;
 223                         break;
 224 #endif
 225
 226                 case 1:   /* show help */
 227                         show_help = true;
 228                         break;
 229
 230                 case 2:   /* show version */
 231                         show_version = true;
 232                         break;
 233
 234                 case 3:   /* bypass security */
 235                         bypass_security = true;
 236                         break;
 237
 238                 case 4:   /* write log entries to a file */
 239                         use_syslog = false;
 240                         use_logfile = true;
 241
 242                         if(!optarg && optind < argc && *argv[optind] != '-') {
 243                                 optarg = argv[optind++];
 244                         }
 245
 246                         if(optarg) {
 247                                 free(logfilename);
 248                                 logfilename = xstrdup(optarg);
 249                         }
 250
 251                         break;
 252
 253                 case 5:   /* open control socket here */
 254                         free(pidfilename);
 255                         pidfilename = xstrdup(optarg);
 256                         break;
 257
 258                 case '?': /* wrong options */
 259                         usage(true);
 260                         goto exit_fail;
 261
 262                 default:
 263                         break;
 264                 }
 265         }
 266
 267         if(optind < argc) {
 268                 fprintf(stderr, "%s: unrecognized argument '%s'\n", argv[0], argv[optind]);
 269                 usage(true);
 270                 goto exit_fail;
 271         }
 272
 273         if(!netname && (netname = getenv("NETNAME"))) {
 274                 netname = xstrdup(netname);
 275         }
 276
 277         /* netname "." is special: a "top-level name" */
 278
 279         if(netname && (!*netname || !strcmp(netname, "."))) {
 280                 free(netname);
 281                 netname = NULL;
 282         }
 283
 284         if(netname && !check_netname(netname, false)) {
 285                 fprintf(stderr, "Invalid character in netname!\n");
 286                 goto exit_fail;
 287         }
 288
 289         if(netname && !check_netname(netname, true)) {
 290                 fprintf(stderr, "Warning: unsafe character in netname!\n");
 291         }
 292
 293         return true;
 294
 295 exit_fail:
 296         free_names();
 297         list_delete_list(cmdline_conf);
 298         cmdline_conf = NULL;
 299         return false;
 300 }
 301
 302 static bool drop_privs(void) {
 303 #ifndef HAVE_MINGW
 304         uid_t uid = 0;
 305
 306         if(switchuser) {
 307                 struct passwd *pw = getpwnam(switchuser);
 308
 309                 if(!pw) {
 310                         logger(DEBUG_ALWAYS, LOG_ERR, "unknown user `%s'", switchuser);
 311                         return false;
 312                 }
 313
 314                 uid = pw->pw_uid;
 315
 316                 if(initgroups(switchuser, pw->pw_gid) != 0 ||
 317                                 setgid(pw->pw_gid) != 0) {
 318                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
 319                                "initgroups", strerror(errno));
 320                         return false;
 321                 }
 322
 323 #ifndef __ANDROID__
 324 // Not supported in android NDK
 325                 endgrent();
 326                 endpwent();
 327 #endif
 328         }
 329
 330         if(do_chroot) {
 331                 tzset();        /* for proper timestamps in logs */
 332
 333                 if(chroot(confbase) != 0 || chdir("/") != 0) {
 334                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
 335                                "chroot", strerror(errno));
 336                         return false;
 337                 }
 338
 339                 free(confbase);
 340                 confbase = xstrdup("");
 341         }
 342
 343         if(switchuser)
 344                 if(setuid(uid) != 0) {
 345                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
 346                                "setuid", strerror(errno));
 347                         return false;
 348                 }
 349
 350 #endif
 351         return true;
 352 }
 353
 354 #ifdef HAVE_MINGW
 355 # define setpriority(level) !SetPriorityClass(GetCurrentProcess(), (level))
 356
 357 static void stop_handler(void *data, int flags) {
 358         (void)data;
 359         (void)flags;
 360
 361         event_exit();
 362 }
 363
 364 static BOOL WINAPI console_ctrl_handler(DWORD type) {
 365         (void)type;
 366
 367         logger(DEBUG_ALWAYS, LOG_NOTICE, "Got console shutdown request");
 368
 369         if(WSASetEvent(stop_io.event) == FALSE) {
 370                 abort();
 371         }
 372
 373         return TRUE;
 374 }
 375 #else
 376 # define NORMAL_PRIORITY_CLASS 0
 377 # define BELOW_NORMAL_PRIORITY_CLASS 10
 378 # define HIGH_PRIORITY_CLASS -10
 379 # define setpriority(level) (setpriority(PRIO_PROCESS, 0, (level)))
 380 #endif
 381
 382 static void cleanup() {
 383         if(config_tree) {
 384                 exit_configuration(&config_tree);
 385         }
 386
 387         list_delete_list(cmdline_conf);
 388         free_names();
 389 }
 390
 391 int main(int argc, char **argv) {
 392         program_name = argv[0];
 393
 394         if(!parse_options(argc, argv)) {
 395                 return 1;
 396         }
 397
 398         if(show_version) {
 399                 printf("%s version %s (built %s %s, protocol %d.%d)\n", PACKAGE,
 400                        BUILD_VERSION, BUILD_DATE, BUILD_TIME, PROT_MAJOR, PROT_MINOR);
 401                 printf("Features:"
 402 #ifdef HAVE_OPENSSL
 403                        " openssl"
 404 #endif
 405 #ifdef HAVE_LIBGCRYPT
 406                        " libgcrypt"
 407 #endif
 408 #ifdef HAVE_LZO
 409                        " comp_lzo"
 410 #endif
 411 #ifdef HAVE_ZLIB
 412                        " comp_zlib"
 413 #endif
 414 #ifdef HAVE_LZ4
 415                        " comp_lz4"
 416 #endif
 417 #ifndef DISABLE_LEGACY
 418                        " legacy_protocol"
 419 #endif
 420 #ifdef ENABLE_JUMBOGRAMS
 421                        " jumbograms"
 422 #endif
 423 #ifdef ENABLE_TUNEMU
 424                        " tunemu"
 425 #endif
 426 #ifdef HAVE_MINIUPNPC
 427                        " miniupnpc"
 428 #endif
 429 #ifdef ENABLE_UML
 430                        " uml"
 431 #endif
 432 #ifdef ENABLE_VDE
 433                        " vde"
 434 #endif
 435                        "\n\n");
 436                 printf("Copyright (C) 1998-2021 Ivo Timmermans, Guus Sliepen and others.\n"
 437                        "See the AUTHORS file for a complete list.\n\n"
 438                        "tinc comes with ABSOLUTELY NO WARRANTY.  This is free software,\n"
 439                        "and you are welcome to redistribute it under certain conditions;\n"
 440                        "see the file COPYING for details.\n");
 441
 442                 return 0;
 443         }
 444
 445         if(show_help) {
 446                 usage(false);
 447                 return 0;
 448         }
 449
 450         make_names(true);
 451         atexit(cleanup);
 452
 453         chdir(confbase);
 454
 455 #ifdef HAVE_MINGW
 456
 457         if(WSAStartup(MAKEWORD(2, 2), &wsa_state)) {
 458                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "WSAStartup", winerror(GetLastError()));
 459                 return 1;
 460         }
 461
 462 #else
 463         // Check if we got an umbilical fd from the process that started us
 464         char *umbstr = getenv("TINC_UMBILICAL");
 465
 466         if(umbstr) {
 467                 umbilical = atoi(umbstr);
 468
 469                 if(fcntl(umbilical, F_GETFL) < 0) {
 470                         umbilical = 0;
 471                 }
 472
 473 #ifdef FD_CLOEXEC
 474
 475                 if(umbilical) {
 476                         fcntl(umbilical, F_SETFD, FD_CLOEXEC);
 477                 }
 478
 479 #endif
 480         }
 481
 482 #endif
 483
 484         openlogger("tinc", use_logfile ? LOGMODE_FILE : LOGMODE_STDERR);
 485
 486         g_argv = argv;
 487
 488         if(getenv("LISTEN_PID") && atoi(getenv("LISTEN_PID")) == getpid()) {
 489                 do_detach = false;
 490         }
 491
 492 #ifdef HAVE_UNSETENV
 493         unsetenv("LISTEN_PID");
 494 #endif
 495
 496         init_configuration(&config_tree);
 497
 498         /* Slllluuuuuuurrrrp! */
 499
 500         gettimeofday(&now, NULL);
 501         srand(now.tv_sec + now.tv_usec);
 502         crypto_init();
 503
 504         if(!read_server_config(config_tree)) {
 505                 return 1;
 506         }
 507
 508         if(!debug_level) {
 509                 get_config_int(lookup_config(config_tree, "LogLevel"), &debug_level);
 510         }
 511
 512 #ifdef HAVE_LZO
 513
 514         if(lzo_init() != LZO_E_OK) {
 515                 logger(DEBUG_ALWAYS, LOG_ERR, "Error initializing LZO compressor!");
 516                 return 1;
 517         }
 518
 519 #endif
 520
 521 #ifdef HAVE_MINGW
 522         io_add_event(&stop_io, stop_handler, NULL, WSACreateEvent());
 523
 524         if(stop_io.event == FALSE) {
 525                 abort();
 526         }
 527
 528         int result;
 529
 530         if(!do_detach || !init_service()) {
 531                 SetConsoleCtrlHandler(console_ctrl_handler, TRUE);
 532                 result = main2(argc, argv);
 533         } else {
 534                 result = 1;
 535         }
 536
 537         if(WSACloseEvent(stop_io.event) == FALSE) {
 538                 abort();
 539         }
 540
 541         io_del(&stop_io);
 542         return result;
 543 }
 544
 545 int main2(int argc, char **argv) {
 546         (void)argc;
 547         (void)argv;
 548 #endif
 549         char *priority = NULL;
 550
 551         if(!detach()) {
 552                 return 1;
 553         }
 554
 555 #ifdef HAVE_MLOCKALL
 556
 557         /* Lock all pages into memory if requested.
 558          * This has to be done after daemon()/fork() so it works for child.
 559          * No need to do that in parent as it's very short-lived. */
 560         if(do_mlock && mlockall(MCL_CURRENT | MCL_FUTURE) != 0) {
 561                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "mlockall",
 562                        strerror(errno));
 563                 return 1;
 564         }
 565
 566 #endif
 567
 568         /* Setup sockets and open device. */
 569
 570         if(!setup_network()) {
 571                 goto end;
 572         }
 573
 574         /* Change process priority */
 575
 576         if(get_config_string(lookup_config(config_tree, "ProcessPriority"), &priority)) {
 577                 if(!strcasecmp(priority, "Normal")) {
 578                         if(setpriority(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, "Low")) {
 583                         if(setpriority(BELOW_NORMAL_PRIORITY_CLASS) != 0) {
 584                                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setpriority", strerror(errno));
 585                                 goto end;
 586                         }
 587                 } else if(!strcasecmp(priority, "High")) {
 588                         if(setpriority(HIGH_PRIORITY_CLASS) != 0) {
 589                                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setpriority", strerror(errno));
 590                                 goto end;
 591                         }
 592                 } else {
 593                         logger(DEBUG_ALWAYS, LOG_ERR, "Invalid priority `%s`!", priority);
 594                         goto end;
 595                 }
 596         }
 597
 598         /* drop privileges */
 599         if(!drop_privs()) {
 600                 goto end;
 601         }
 602
 603         /* Start main loop. It only exits when tinc is killed. */
 604
 605         logger(DEBUG_ALWAYS, LOG_NOTICE, "Ready");
 606
 607         if(umbilical) { // snip!
 608                 write(umbilical, "", 1);
 609                 close(umbilical);
 610                 umbilical = 0;
 611         }
 612
 613         try_outgoing_connections();
 614
 615         status = main_loop();
 616
 617         /* Shutdown properly. */
 618
 619 end:
 620         close_network_connections();
 621
 622         logger(DEBUG_ALWAYS, LOG_NOTICE, "Terminating");
 623
 624         free(priority);
 625
 626         crypto_exit();
 627
 628         return status;
 629 }