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 "control.h"
  52 #include "crypto.h"
  53 #include "device.h"
  54 #include "event.h"
  55 #include "logger.h"
  56 #include "names.h"
  57 #include "net.h"
  58 #include "netutl.h"
  59 #include "process.h"
  60 #include "protocol.h"
  61 #include "utils.h"
  62 #include "xalloc.h"
  63 #include "version.h"
  64
  65 /* If nonzero, display usage information and exit. */
  66 static bool show_help = false;
  67
  68 /* If nonzero, print the version on standard output and exit.  */
  69 static bool show_version = false;
  70
  71 /* If nonzero, use null ciphers and skip all key exchanges. */
  72 bool bypass_security = false;
  73
  74 #ifdef HAVE_MLOCKALL
  75 /* If nonzero, disable swapping for this process. */
  76 static bool do_mlock = false;
  77 #endif
  78
  79 #ifndef HAVE_MINGW
  80 /* If nonzero, chroot to netdir after startup. */
  81 static bool do_chroot = false;
  82
  83 /* If !NULL, do setuid to given user after startup */
  84 static const char *switchuser = NULL;
  85 #endif
  86
  87 /* If nonzero, write log entries to a separate file. */
  88 bool use_logfile = false;
  89
  90 /* If nonzero, use syslog instead of stderr in no-detach mode. */
  91 bool use_syslog = false;
  92
  93 char **g_argv;                  /* a copy of the cmdline arguments */
  94
  95 static int status = 1;
  96
  97 static struct option const long_options[] = {
  98         {"config", required_argument, NULL, 'c'},
  99         {"net", required_argument, NULL, 'n'},
 100         {"help", no_argument, NULL, 1},
 101         {"version", no_argument, NULL, 2},
 102         {"no-detach", no_argument, NULL, 'D'},
 103         {"debug", optional_argument, NULL, 'd'},
 104         {"bypass-security", no_argument, NULL, 3},
 105         {"mlock", no_argument, NULL, 'L'},
 106         {"chroot", no_argument, NULL, 'R'},
 107         {"user", required_argument, NULL, 'U'},
 108         {"logfile", optional_argument, NULL, 4},
 109         {"syslog", no_argument, NULL, 's'},
 110         {"pidfile", required_argument, NULL, 5},
 111         {"option", required_argument, NULL, 'o'},
 112         {NULL, 0, NULL, 0}
 113 };
 114
 115 #ifdef HAVE_MINGW
 116 static struct WSAData wsa_state;
 117 int main2(int argc, char **argv);
 118 #endif
 119
 120 static void usage(bool status) {
 121         if(status)
 122                 fprintf(stderr, "Try `%s --help\' for more information.\n",
 123                         program_name);
 124         else {
 125                 printf("Usage: %s [option]...\n\n", program_name);
 126                 printf("  -c, --config=DIR              Read configuration options from DIR.\n"
 127                        "  -D, --no-detach               Don't fork and detach.\n"
 128                        "  -d, --debug[=LEVEL]           Increase debug level or set it to LEVEL.\n"
 129                        "  -n, --net=NETNAME             Connect to net NETNAME.\n"
 130 #ifdef HAVE_MLOCKALL
 131                        "  -L, --mlock                   Lock tinc into main memory.\n"
 132 #endif
 133                        "      --logfile[=FILENAME]      Write log entries to a logfile.\n"
 134                        "  -s  --syslog                  Use syslog instead of stderr with --no-detach.\n"
 135                        "      --pidfile=FILENAME        Write PID and control socket cookie to FILENAME.\n"
 136                        "      --bypass-security         Disables meta protocol security, for debugging.\n"
 137                        "  -o, --option[HOST.]KEY=VALUE  Set global/host configuration value.\n"
 138 #ifndef HAVE_MINGW
 139                        "  -R, --chroot                  chroot to NET dir at startup.\n"
 140                        "  -U, --user=USER               setuid to given USER at startup.\n"
 141 #endif
 142                        "      --help                    Display this help and exit.\n"
 143                        "      --version                 Output version information and exit.\n\n");
 144                 printf("Report bugs to tinc@tinc-vpn.org.\n");
 145         }
 146 }
 147
 148 static bool parse_options(int argc, char **argv) {
 149         config_t *cfg;
 150         int r;
 151         int option_index = 0;
 152         int lineno = 0;
 153
 154         cmdline_conf = list_alloc((list_action_t)free_config);
 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                         confbase = xstrdup(optarg);
 163                         break;
 164
 165                 case 'D': /* no detach */
 166                         do_detach = false;
 167                         break;
 168
 169                 case 'L': /* no detach */
 170 #ifndef HAVE_MLOCKALL
 171                         logger(DEBUG_ALWAYS, LOG_ERR, "The %s option is not supported on this platform.", argv[optind - 1]);
 172                         return false;
 173 #else
 174                         do_mlock = true;
 175                         break;
 176 #endif
 177
 178                 case 'd': /* increase debug level */
 179                         if(!optarg && optind < argc && *argv[optind] != '-') {
 180                                 optarg = argv[optind++];
 181                         }
 182
 183                         if(optarg) {
 184                                 debug_level = atoi(optarg);
 185                         } else {
 186                                 debug_level++;
 187                         }
 188
 189                         break;
 190
 191                 case 'n': /* net name given */
 192                         netname = xstrdup(optarg);
 193                         break;
 194
 195                 case 's': /* syslog */
 196                         use_logfile = false;
 197                         use_syslog = true;
 198                         break;
 199
 200                 case 'o': /* option */
 201                         cfg = parse_config_line(optarg, NULL, ++lineno);
 202
 203                         if(!cfg) {
 204                                 return false;
 205                         }
 206
 207                         list_insert_tail(cmdline_conf, cfg);
 208                         break;
 209
 210 #ifdef HAVE_MINGW
 211
 212                 case 'R':
 213                 case 'U':
 214                         logger(DEBUG_ALWAYS, LOG_ERR, "The %s option is not supported on this platform.", argv[optind - 1]);
 215                         return false;
 216 #else
 217
 218                 case 'R': /* chroot to NETNAME dir */
 219                         do_chroot = true;
 220                         break;
 221
 222                 case 'U': /* setuid to USER */
 223                         switchuser = optarg;
 224                         break;
 225 #endif
 226
 227                 case 1:   /* show help */
 228                         show_help = true;
 229                         break;
 230
 231                 case 2:   /* show version */
 232                         show_version = true;
 233                         break;
 234
 235                 case 3:   /* bypass security */
 236                         bypass_security = true;
 237                         break;
 238
 239                 case 4:   /* write log entries to a file */
 240                         use_syslog = false;
 241                         use_logfile = true;
 242
 243                         if(!optarg && optind < argc && *argv[optind] != '-') {
 244                                 optarg = argv[optind++];
 245                         }
 246
 247                         if(optarg) {
 248                                 logfilename = xstrdup(optarg);
 249                         }
 250
 251                         break;
 252
 253                 case 5:   /* open control socket here */
 254                         pidfilename = xstrdup(optarg);
 255                         break;
 256
 257                 case '?': /* wrong options */
 258                         usage(true);
 259                         return false;
 260
 261                 default:
 262                         break;
 263                 }
 264         }
 265
 266         if(optind < argc) {
 267                 fprintf(stderr, "%s: unrecognized argument '%s'\n", argv[0], argv[optind]);
 268                 usage(true);
 269                 return false;
 270         }
 271
 272         if(!netname && (netname = getenv("NETNAME"))) {
 273                 netname = xstrdup(netname);
 274         }
 275
 276         /* netname "." is special: a "top-level name" */
 277
 278         if(netname && (!*netname || !strcmp(netname, "."))) {
 279                 free(netname);
 280                 netname = NULL;
 281         }
 282
 283         if(netname && !check_netname(netname, false)) {
 284                 fprintf(stderr, "Invalid character in netname!\n");
 285                 return false;
 286         }
 287
 288         if(netname && !check_netname(netname, true)) {
 289                 fprintf(stderr, "Warning: unsafe character in netname!\n");
 290         }
 291
 292         return true;
 293 }
 294
 295 static bool drop_privs(void) {
 296 #ifndef HAVE_MINGW
 297         uid_t uid = 0;
 298
 299         if(switchuser) {
 300                 struct passwd *pw = getpwnam(switchuser);
 301
 302                 if(!pw) {
 303                         logger(DEBUG_ALWAYS, LOG_ERR, "unknown user `%s'", switchuser);
 304                         return false;
 305                 }
 306
 307                 uid = pw->pw_uid;
 308
 309                 if(initgroups(switchuser, pw->pw_gid) != 0 ||
 310                                 setgid(pw->pw_gid) != 0) {
 311                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
 312                                "initgroups", strerror(errno));
 313                         return false;
 314                 }
 315
 316 #ifndef __ANDROID__
 317 // Not supported in android NDK
 318                 endgrent();
 319                 endpwent();
 320 #endif
 321         }
 322
 323         if(do_chroot) {
 324                 tzset();        /* for proper timestamps in logs */
 325
 326                 if(chroot(confbase) != 0 || chdir("/") != 0) {
 327                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
 328                                "chroot", strerror(errno));
 329                         return false;
 330                 }
 331
 332                 free(confbase);
 333                 confbase = xstrdup("");
 334         }
 335
 336         if(switchuser)
 337                 if(setuid(uid) != 0) {
 338                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
 339                                "setuid", strerror(errno));
 340                         return false;
 341                 }
 342
 343 #endif
 344         return true;
 345 }
 346
 347 #ifdef HAVE_MINGW
 348 # define setpriority(level) !SetPriorityClass(GetCurrentProcess(), (level))
 349
 350 static void stop_handler(void *data, int flags) {
 351         (void)data;
 352         (void)flags;
 353
 354         event_exit();
 355 }
 356
 357 static BOOL WINAPI console_ctrl_handler(DWORD type) {
 358         (void)type;
 359
 360         logger(DEBUG_ALWAYS, LOG_NOTICE, "Got console shutdown request");
 361
 362         if(WSASetEvent(stop_io.event) == FALSE) {
 363                 abort();
 364         }
 365
 366         return TRUE;
 367 }
 368 #else
 369 # define NORMAL_PRIORITY_CLASS 0
 370 # define BELOW_NORMAL_PRIORITY_CLASS 10
 371 # define HIGH_PRIORITY_CLASS -10
 372 # define setpriority(level) (setpriority(PRIO_PROCESS, 0, (level)))
 373 #endif
 374
 375 int main(int argc, char **argv) {
 376         program_name = argv[0];
 377
 378         if(!parse_options(argc, argv)) {
 379                 return 1;
 380         }
 381
 382         if(show_version) {
 383                 printf("%s version %s (built %s %s, protocol %d.%d)\n", PACKAGE,
 384                        BUILD_VERSION, BUILD_DATE, BUILD_TIME, PROT_MAJOR, PROT_MINOR);
 385                 printf("Features:"
 386 #ifdef HAVE_OPENSSL
 387                        " openssl"
 388 #endif
 389 #ifdef HAVE_LIBGCRYPT
 390                        " libgcrypt"
 391 #endif
 392 #ifdef HAVE_LZO
 393                        " comp_lzo"
 394 #endif
 395 #ifdef HAVE_ZLIB
 396                        " comp_zlib"
 397 #endif
 398 #ifdef HAVE_LZ4
 399                        " comp_lz4"
 400 #endif
 401 #ifndef DISABLE_LEGACY
 402                        " legacy_protocol"
 403 #endif
 404 #ifdef ENABLE_JUMBOGRAMS
 405                        " jumbograms"
 406 #endif
 407 #ifdef ENABLE_TUNEMU
 408                        " tunemu"
 409 #endif
 410 #ifdef HAVE_MINIUPNPC
 411                        " miniupnpc"
 412 #endif
 413 #ifdef ENABLE_UML
 414                        " uml"
 415 #endif
 416 #ifdef ENABLE_VDE
 417                        " vde"
 418 #endif
 419                        "\n\n");
 420                 printf("Copyright (C) 1998-2021 Ivo Timmermans, Guus Sliepen and others.\n"
 421                        "See the AUTHORS file for a complete list.\n\n"
 422                        "tinc comes with ABSOLUTELY NO WARRANTY.  This is free software,\n"
 423                        "and you are welcome to redistribute it under certain conditions;\n"
 424                        "see the file COPYING for details.\n");
 425
 426                 return 0;
 427         }
 428
 429         if(show_help) {
 430                 usage(false);
 431                 return 0;
 432         }
 433
 434         make_names(true);
 435         chdir(confbase);
 436
 437 #ifdef HAVE_MINGW
 438
 439         if(WSAStartup(MAKEWORD(2, 2), &wsa_state)) {
 440                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "WSAStartup", winerror(GetLastError()));
 441                 return 1;
 442         }
 443
 444 #else
 445         // Check if we got an umbilical fd from the process that started us
 446         char *umbstr = getenv("TINC_UMBILICAL");
 447
 448         if(umbstr) {
 449                 umbilical = atoi(umbstr);
 450
 451                 if(fcntl(umbilical, F_GETFL) < 0) {
 452                         umbilical = 0;
 453                 }
 454
 455 #ifdef FD_CLOEXEC
 456
 457                 if(umbilical) {
 458                         fcntl(umbilical, F_SETFD, FD_CLOEXEC);
 459                 }
 460
 461 #endif
 462         }
 463
 464 #endif
 465
 466         openlogger("tinc", use_logfile ? LOGMODE_FILE : LOGMODE_STDERR);
 467
 468         g_argv = argv;
 469
 470         if(getenv("LISTEN_PID") && atoi(getenv("LISTEN_PID")) == getpid()) {
 471                 do_detach = false;
 472         }
 473
 474 #ifdef HAVE_UNSETENV
 475         unsetenv("LISTEN_PID");
 476 #endif
 477
 478         init_configuration(&config_tree);
 479
 480         /* Slllluuuuuuurrrrp! */
 481
 482         gettimeofday(&now, NULL);
 483         srand(now.tv_sec + now.tv_usec);
 484         crypto_init();
 485
 486         if(!read_server_config()) {
 487                 return 1;
 488         }
 489
 490         if(!debug_level) {
 491                 get_config_int(lookup_config(config_tree, "LogLevel"), &debug_level);
 492         }
 493
 494 #ifdef HAVE_LZO
 495
 496         if(lzo_init() != LZO_E_OK) {
 497                 logger(DEBUG_ALWAYS, LOG_ERR, "Error initializing LZO compressor!");
 498                 return 1;
 499         }
 500
 501 #endif
 502
 503 #ifdef HAVE_MINGW
 504         io_add_event(&stop_io, stop_handler, NULL, WSACreateEvent());
 505
 506         if(stop_io.event == FALSE) {
 507                 abort();
 508         }
 509
 510         int result;
 511
 512         if(!do_detach || !init_service()) {
 513                 SetConsoleCtrlHandler(console_ctrl_handler, TRUE);
 514                 result = main2(argc, argv);
 515         } else {
 516                 result = 1;
 517         }
 518
 519         if(WSACloseEvent(stop_io.event) == FALSE) {
 520                 abort();
 521         }
 522
 523         io_del(&stop_io);
 524         return result;
 525 }
 526
 527 int main2(int argc, char **argv) {
 528         (void)argc;
 529         (void)argv;
 530 #endif
 531         char *priority = NULL;
 532
 533         if(!detach()) {
 534                 return 1;
 535         }
 536
 537 #ifdef HAVE_MLOCKALL
 538
 539         /* Lock all pages into memory if requested.
 540          * This has to be done after daemon()/fork() so it works for child.
 541          * No need to do that in parent as it's very short-lived. */
 542         if(do_mlock && mlockall(MCL_CURRENT | MCL_FUTURE) != 0) {
 543                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "mlockall",
 544                        strerror(errno));
 545                 return 1;
 546         }
 547
 548 #endif
 549
 550         /* Setup sockets and open device. */
 551
 552         if(!setup_network()) {
 553                 goto end;
 554         }
 555
 556         /* Change process priority */
 557
 558         if(get_config_string(lookup_config(config_tree, "ProcessPriority"), &priority)) {
 559                 if(!strcasecmp(priority, "Normal")) {
 560                         if(setpriority(NORMAL_PRIORITY_CLASS) != 0) {
 561                                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setpriority", strerror(errno));
 562                                 goto end;
 563                         }
 564                 } else if(!strcasecmp(priority, "Low")) {
 565                         if(setpriority(BELOW_NORMAL_PRIORITY_CLASS) != 0) {
 566                                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setpriority", strerror(errno));
 567                                 goto end;
 568                         }
 569                 } else if(!strcasecmp(priority, "High")) {
 570                         if(setpriority(HIGH_PRIORITY_CLASS) != 0) {
 571                                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setpriority", strerror(errno));
 572                                 goto end;
 573                         }
 574                 } else {
 575                         logger(DEBUG_ALWAYS, LOG_ERR, "Invalid priority `%s`!", priority);
 576                         goto end;
 577                 }
 578         }
 579
 580         /* drop privileges */
 581         if(!drop_privs()) {
 582                 goto end;
 583         }
 584
 585         /* Start main loop. It only exits when tinc is killed. */
 586
 587         logger(DEBUG_ALWAYS, LOG_NOTICE, "Ready");
 588
 589         if(umbilical) { // snip!
 590                 write(umbilical, "", 1);
 591                 close(umbilical);
 592                 umbilical = 0;
 593         }
 594
 595         try_outgoing_connections();
 596
 597         status = main_loop();
 598
 599         /* Shutdown properly. */
 600
 601 end:
 602         close_network_connections();
 603
 604         logger(DEBUG_ALWAYS, LOG_NOTICE, "Terminating");
 605
 606         free(priority);
 607
 608         crypto_exit();
 609
 610         exit_configuration(&config_tree);
 611         free(cmdline_conf);
 612         free_names();
 613
 614         return status;
 615 }