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                         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_delete_list(cmdline_conf);
 301         cmdline_conf = NULL;
 302         return false;
 303 }
 304
 305 static bool drop_privs(void) {
 306 #ifndef HAVE_MINGW
 307         uid_t uid = 0;
 308
 309         if(switchuser) {
 310                 struct passwd *pw = getpwnam(switchuser);
 311
 312                 if(!pw) {
 313                         logger(DEBUG_ALWAYS, LOG_ERR, "unknown user `%s'", switchuser);
 314                         return false;
 315                 }
 316
 317                 uid = pw->pw_uid;
 318
 319                 if(initgroups(switchuser, pw->pw_gid) != 0 ||
 320                                 setgid(pw->pw_gid) != 0) {
 321                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
 322                                "initgroups", strerror(errno));
 323                         return false;
 324                 }
 325
 326 #ifndef __ANDROID__
 327 // Not supported in android NDK
 328                 endgrent();
 329                 endpwent();
 330 #endif
 331         }
 332
 333         if(do_chroot) {
 334                 tzset();        /* for proper timestamps in logs */
 335
 336                 if(chroot(confbase) != 0 || chdir("/") != 0) {
 337                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
 338                                "chroot", strerror(errno));
 339                         return false;
 340                 }
 341
 342                 free(confbase);
 343                 confbase = xstrdup("");
 344         }
 345
 346         if(switchuser)
 347                 if(setuid(uid) != 0) {
 348                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
 349                                "setuid", strerror(errno));
 350                         return false;
 351                 }
 352
 353 #endif
 354         return true;
 355 }
 356
 357 #ifdef HAVE_MINGW
 358 # define setpriority(level) !SetPriorityClass(GetCurrentProcess(), (level))
 359
 360 static void stop_handler(void *data, int flags) {
 361         (void)data;
 362         (void)flags;
 363
 364         event_exit();
 365 }
 366
 367 static BOOL WINAPI console_ctrl_handler(DWORD type) {
 368         (void)type;
 369
 370         logger(DEBUG_ALWAYS, LOG_NOTICE, "Got console shutdown request");
 371
 372         if(WSASetEvent(stop_io.event) == FALSE) {
 373                 abort();
 374         }
 375
 376         return TRUE;
 377 }
 378 #else
 379 # define NORMAL_PRIORITY_CLASS 0
 380 # define BELOW_NORMAL_PRIORITY_CLASS 10
 381 # define HIGH_PRIORITY_CLASS -10
 382 # define setpriority(level) (setpriority(PRIO_PROCESS, 0, (level)))
 383 #endif
 384
 385 static void cleanup() {
 386         if(config_tree) {
 387                 exit_configuration(&config_tree);
 388         }
 389
 390         list_delete_list(cmdline_conf);
 391         free_names();
 392 }
 393
 394 int main(int argc, char **argv) {
 395         program_name = argv[0];
 396
 397         if(!parse_options(argc, argv)) {
 398                 return 1;
 399         }
 400
 401         if(show_version) {
 402                 printf("%s version %s (built %s %s, protocol %d.%d)\n", PACKAGE,
 403                        BUILD_VERSION, BUILD_DATE, BUILD_TIME, PROT_MAJOR, PROT_MINOR);
 404                 printf("Features:"
 405 #ifdef HAVE_OPENSSL
 406                        " openssl"
 407 #endif
 408 #ifdef HAVE_LIBGCRYPT
 409                        " libgcrypt"
 410 #endif
 411 #ifdef HAVE_LZO
 412                        " comp_lzo"
 413 #endif
 414 #ifdef HAVE_ZLIB
 415                        " comp_zlib"
 416 #endif
 417 #ifdef HAVE_LZ4
 418                        " comp_lz4"
 419 #endif
 420 #ifndef DISABLE_LEGACY
 421                        " legacy_protocol"
 422 #endif
 423 #ifdef ENABLE_JUMBOGRAMS
 424                        " jumbograms"
 425 #endif
 426 #ifdef ENABLE_TUNEMU
 427                        " tunemu"
 428 #endif
 429 #ifdef HAVE_MINIUPNPC
 430                        " miniupnpc"
 431 #endif
 432 #ifdef ENABLE_UML
 433                        " uml"
 434 #endif
 435 #ifdef ENABLE_VDE
 436                        " vde"
 437 #endif
 438                        "\n\n");
 439                 printf("Copyright (C) 1998-2021 Ivo Timmermans, Guus Sliepen and others.\n"
 440                        "See the AUTHORS file for a complete list.\n\n"
 441                        "tinc comes with ABSOLUTELY NO WARRANTY.  This is free software,\n"
 442                        "and you are welcome to redistribute it under certain conditions;\n"
 443                        "see the file COPYING for details.\n");
 444
 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         chdir(confbase);
 457
 458 #ifdef HAVE_MINGW
 459
 460         if(WSAStartup(MAKEWORD(2, 2), &wsa_state)) {
 461                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "WSAStartup", winerror(GetLastError()));
 462                 return 1;
 463         }
 464
 465 #else
 466         // Check if we got an umbilical fd from the process that started us
 467         char *umbstr = getenv("TINC_UMBILICAL");
 468
 469         if(umbstr) {
 470                 umbilical = atoi(umbstr);
 471
 472                 if(fcntl(umbilical, F_GETFL) < 0) {
 473                         umbilical = 0;
 474                 }
 475
 476 #ifdef FD_CLOEXEC
 477
 478                 if(umbilical) {
 479                         fcntl(umbilical, F_SETFD, FD_CLOEXEC);
 480                 }
 481
 482 #endif
 483         }
 484
 485 #endif
 486
 487         openlogger("tinc", use_logfile ? LOGMODE_FILE : LOGMODE_STDERR);
 488
 489         g_argv = argv;
 490
 491         if(getenv("LISTEN_PID") && atoi(getenv("LISTEN_PID")) == getpid()) {
 492                 do_detach = false;
 493         }
 494
 495 #ifdef HAVE_UNSETENV
 496         unsetenv("LISTEN_PID");
 497 #endif
 498
 499         init_configuration(&config_tree);
 500
 501         /* Slllluuuuuuurrrrp! */
 502
 503         gettimeofday(&now, NULL);
 504         srand(now.tv_sec + now.tv_usec);
 505         crypto_init();
 506
 507         if(!read_server_config(config_tree)) {
 508                 return 1;
 509         }
 510
 511         if(!debug_level) {
 512                 get_config_int(lookup_config(config_tree, "LogLevel"), &debug_level);
 513         }
 514
 515 #ifdef HAVE_LZO
 516
 517         if(lzo_init() != LZO_E_OK) {
 518                 logger(DEBUG_ALWAYS, LOG_ERR, "Error initializing LZO compressor!");
 519                 return 1;
 520         }
 521
 522 #endif
 523
 524 #ifdef HAVE_MINGW
 525         io_add_event(&stop_io, stop_handler, NULL, WSACreateEvent());
 526
 527         if(stop_io.event == FALSE) {
 528                 abort();
 529         }
 530
 531         int result;
 532
 533         if(!do_detach || !init_service()) {
 534                 SetConsoleCtrlHandler(console_ctrl_handler, TRUE);
 535                 result = main2(argc, argv);
 536         } else {
 537                 result = 1;
 538         }
 539
 540         if(WSACloseEvent(stop_io.event) == FALSE) {
 541                 abort();
 542         }
 543
 544         io_del(&stop_io);
 545         return result;
 546 }
 547
 548 int main2(int argc, char **argv) {
 549         (void)argc;
 550         (void)argv;
 551 #endif
 552         char *priority = NULL;
 553
 554         if(!detach()) {
 555                 return 1;
 556         }
 557
 558 #ifdef HAVE_MLOCKALL
 559
 560         /* Lock all pages into memory if requested.
 561          * This has to be done after daemon()/fork() so it works for child.
 562          * No need to do that in parent as it's very short-lived. */
 563         if(do_mlock && mlockall(MCL_CURRENT | MCL_FUTURE) != 0) {
 564                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "mlockall",
 565                        strerror(errno));
 566                 return 1;
 567         }
 568
 569 #endif
 570
 571         /* Setup sockets and open device. */
 572
 573         if(!setup_network()) {
 574                 goto end;
 575         }
 576
 577         /* Change process priority */
 578
 579         if(get_config_string(lookup_config(config_tree, "ProcessPriority"), &priority)) {
 580                 if(!strcasecmp(priority, "Normal")) {
 581                         if(setpriority(NORMAL_PRIORITY_CLASS) != 0) {
 582                                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setpriority", strerror(errno));
 583                                 goto end;
 584                         }
 585                 } else if(!strcasecmp(priority, "Low")) {
 586                         if(setpriority(BELOW_NORMAL_PRIORITY_CLASS) != 0) {
 587                                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setpriority", strerror(errno));
 588                                 goto end;
 589                         }
 590                 } else if(!strcasecmp(priority, "High")) {
 591                         if(setpriority(HIGH_PRIORITY_CLASS) != 0) {
 592                                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setpriority", strerror(errno));
 593                                 goto end;
 594                         }
 595                 } else {
 596                         logger(DEBUG_ALWAYS, LOG_ERR, "Invalid priority `%s`!", priority);
 597                         goto end;
 598                 }
 599         }
 600
 601         /* drop privileges */
 602         if(!drop_privs()) {
 603                 goto end;
 604         }
 605
 606         /* Start main loop. It only exits when tinc is killed. */
 607
 608         logger(DEBUG_ALWAYS, LOG_NOTICE, "Ready");
 609
 610         if(umbilical) { // snip!
 611                 write(umbilical, "", 1);
 612                 close(umbilical);
 613                 umbilical = 0;
 614         }
 615
 616         try_outgoing_connections();
 617
 618         status = main_loop();
 619
 620         /* Shutdown properly. */
 621
 622 end:
 623         close_network_connections();
 624
 625         logger(DEBUG_ALWAYS, LOG_NOTICE, "Terminating");
 626
 627         free(priority);
 628
 629         crypto_exit();
 630
 631         return status;
 632 }