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                   2000-2016 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 #ifndef HAVE_MINGW
  41 #include <pwd.h>
  42 #include <grp.h>
  43 #include <time.h>
  44 #endif
  45
  46 #include "conf.h"
  47 #include "control.h"
  48 #include "crypto.h"
  49 #include "device.h"
  50 #include "event.h"
  51 #include "logger.h"
  52 #include "names.h"
  53 #include "net.h"
  54 #include "netutl.h"
  55 #include "process.h"
  56 #include "protocol.h"
  57 #include "utils.h"
  58 #include "xalloc.h"
  59 #include "version.h"
  60
  61 /* If nonzero, display usage information and exit. */
  62 static bool show_help = false;
  63
  64 /* If nonzero, print the version on standard output and exit.  */
  65 static bool show_version = false;
  66
  67 /* If nonzero, use null ciphers and skip all key exchanges. */
  68 bool bypass_security = false;
  69
  70 #ifdef HAVE_MLOCKALL
  71 /* If nonzero, disable swapping for this process. */
  72 static bool do_mlock = false;
  73 #endif
  74
  75 #ifndef HAVE_MINGW
  76 /* If nonzero, chroot to netdir after startup. */
  77 static bool do_chroot = false;
  78
  79 /* If !NULL, do setuid to given user after startup */
  80 static const char *switchuser = NULL;
  81 #endif
  82
  83 /* If nonzero, write log entries to a separate file. */
  84 bool use_logfile = false;
  85
  86 /* If nonzero, use syslog instead of stderr in no-detach mode. */
  87 bool use_syslog = false;
  88
  89 char **g_argv;                  /* a copy of the cmdline arguments */
  90
  91 static int status = 1;
  92
  93 static struct option const long_options[] = {
  94         {"config", required_argument, NULL, 'c'},
  95         {"net", required_argument, NULL, 'n'},
  96         {"help", no_argument, NULL, 1},
  97         {"version", no_argument, NULL, 2},
  98         {"no-detach", no_argument, NULL, 'D'},
  99         {"debug", optional_argument, NULL, 'd'},
 100         {"bypass-security", no_argument, NULL, 3},
 101         {"mlock", no_argument, NULL, 'L'},
 102         {"chroot", no_argument, NULL, 'R'},
 103         {"user", required_argument, NULL, 'U'},
 104         {"logfile", optional_argument, NULL, 4},
 105         {"syslog", no_argument, NULL, 's'},
 106         {"pidfile", required_argument, NULL, 5},
 107         {"option", required_argument, NULL, 'o'},
 108         {NULL, 0, NULL, 0}
 109 };
 110
 111 #ifdef HAVE_MINGW
 112 static struct WSAData wsa_state;
 113 int main2(int argc, char **argv);
 114 #endif
 115
 116 static void usage(bool status) {
 117         if(status)
 118                 fprintf(stderr, "Try `%s --help\' for more information.\n",
 119                                 program_name);
 120         else {
 121                 printf("Usage: %s [option]...\n\n", program_name);
 122                 printf( "  -c, --config=DIR              Read configuration options from DIR.\n"
 123                                 "  -D, --no-detach               Don't fork and detach.\n"
 124                                 "  -d, --debug[=LEVEL]           Increase debug level or set it to LEVEL.\n"
 125                                 "  -n, --net=NETNAME             Connect to net NETNAME.\n"
 126 #ifdef HAVE_MLOCKALL
 127                                 "  -L, --mlock                   Lock tinc into main memory.\n"
 128 #endif
 129                                 "      --logfile[=FILENAME]      Write log entries to a logfile.\n"
 130                                 "  -s  --syslog                  Use syslog instead of stderr with --no-detach.\n"
 131                                 "      --pidfile=FILENAME        Write PID and control socket cookie to FILENAME.\n"
 132                                 "      --bypass-security         Disables meta protocol security, for debugging.\n"
 133                                 "  -o, --option[HOST.]KEY=VALUE  Set global/host configuration value.\n"
 134 #ifndef HAVE_MINGW
 135                                 "  -R, --chroot                  chroot to NET dir at startup.\n"
 136                                 "  -U, --user=USER               setuid to given USER at startup.\n"
 137 #endif
 138                                 "      --help                    Display this help and exit.\n"
 139                                 "      --version                 Output version information and exit.\n\n");
 140                 printf("Report bugs to tinc@tinc-vpn.org.\n");
 141         }
 142 }
 143
 144 static bool parse_options(int argc, char **argv) {
 145         config_t *cfg;
 146         int r;
 147         int option_index = 0;
 148         int lineno = 0;
 149
 150         cmdline_conf = list_alloc((list_action_t)free_config);
 151
 152         while((r = getopt_long(argc, argv, "c:DLd::n:so:RU:", long_options, &option_index)) != EOF) {
 153                 switch (r) {
 154                         case 0:   /* long option */
 155                                 break;
 156
 157                         case 'c': /* config file */
 158                                 confbase = xstrdup(optarg);
 159                                 break;
 160
 161                         case 'D': /* no detach */
 162                                 do_detach = false;
 163                                 break;
 164
 165                         case 'L': /* no detach */
 166 #ifndef HAVE_MLOCKALL
 167                                 logger(DEBUG_ALWAYS, LOG_ERR, "The %s option is not supported on this platform.", argv[optind - 1]);
 168                                 return false;
 169 #else
 170                                 do_mlock = true;
 171                                 break;
 172 #endif
 173
 174                         case 'd': /* increase debug level */
 175                                 if(!optarg && optind < argc && *argv[optind] != '-')
 176                                         optarg = argv[optind++];
 177                                 if(optarg)
 178                                         debug_level = atoi(optarg);
 179                                 else
 180                                         debug_level++;
 181                                 break;
 182
 183                         case 'n': /* net name given */
 184                                 netname = xstrdup(optarg);
 185                                 break;
 186
 187                         case 's': /* syslog */
 188                                 use_logfile = false;
 189                                 use_syslog = true;
 190                                 break;
 191
 192                         case 'o': /* option */
 193                                 cfg = parse_config_line(optarg, NULL, ++lineno);
 194                                 if (!cfg)
 195                                         return false;
 196                                 list_insert_tail(cmdline_conf, cfg);
 197                                 break;
 198
 199 #ifdef HAVE_MINGW
 200                         case 'R':
 201                         case 'U':
 202                                 logger(DEBUG_ALWAYS, LOG_ERR, "The %s option is not supported on this platform.", argv[optind - 1]);
 203                                 return false;
 204 #else
 205                         case 'R': /* chroot to NETNAME dir */
 206                                 do_chroot = true;
 207                                 break;
 208
 209                         case 'U': /* setuid to USER */
 210                                 switchuser = optarg;
 211                                 break;
 212 #endif
 213
 214                         case 1:   /* show help */
 215                                 show_help = true;
 216                                 break;
 217
 218                         case 2:   /* show version */
 219                                 show_version = true;
 220                                 break;
 221
 222                         case 3:   /* bypass security */
 223                                 bypass_security = true;
 224                                 break;
 225
 226                         case 4:   /* write log entries to a file */
 227                                 use_syslog = false;
 228                                 use_logfile = true;
 229                                 if(!optarg && optind < argc && *argv[optind] != '-')
 230                                         optarg = argv[optind++];
 231                                 if(optarg)
 232                                         logfilename = xstrdup(optarg);
 233                                 break;
 234
 235                         case 5:   /* open control socket here */
 236                                 pidfilename = xstrdup(optarg);
 237                                 break;
 238
 239                         case '?': /* wrong options */
 240                                 usage(true);
 241                                 return false;
 242
 243                         default:
 244                                 break;
 245                 }
 246         }
 247
 248         if(optind < argc) {
 249                 fprintf(stderr, "%s: unrecognized argument '%s'\n", argv[0], argv[optind]);
 250                 usage(true);
 251                 return false;
 252         }
 253
 254         if(!netname && (netname = getenv("NETNAME")))
 255                 netname = xstrdup(netname);
 256
 257         /* netname "." is special: a "top-level name" */
 258
 259         if(netname && (!*netname || !strcmp(netname, "."))) {
 260                 free(netname);
 261                 netname = NULL;
 262         }
 263
 264         if(netname && !check_netname(netname, false)) {
 265                 fprintf(stderr, "Invalid character in netname!\n");
 266                 return false;
 267         }
 268
 269         if(netname && !check_netname(netname, true))
 270                 fprintf(stderr, "Warning: unsafe character in netname!\n");
 271
 272         return true;
 273 }
 274
 275 static bool drop_privs(void) {
 276 #ifndef HAVE_MINGW
 277         uid_t uid = 0;
 278         if (switchuser) {
 279                 struct passwd *pw = getpwnam(switchuser);
 280                 if (!pw) {
 281                         logger(DEBUG_ALWAYS, LOG_ERR, "unknown user `%s'", switchuser);
 282                         return false;
 283                 }
 284                 uid = pw->pw_uid;
 285                 if (initgroups(switchuser, pw->pw_gid) != 0 ||
 286                     setgid(pw->pw_gid) != 0) {
 287                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
 288                                "initgroups", strerror(errno));
 289                         return false;
 290                 }
 291 #ifndef __ANDROID__
 292 // Not supported in android NDK
 293                 endgrent();
 294                 endpwent();
 295 #endif
 296         }
 297         if (do_chroot) {
 298                 tzset();        /* for proper timestamps in logs */
 299                 if (chroot(confbase) != 0 || chdir("/") != 0) {
 300                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
 301                                "chroot", strerror(errno));
 302                         return false;
 303                 }
 304                 free(confbase);
 305                 confbase = xstrdup("");
 306         }
 307         if (switchuser)
 308                 if (setuid(uid) != 0) {
 309                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
 310                                "setuid", strerror(errno));
 311                         return false;
 312                 }
 313 #endif
 314         return true;
 315 }
 316
 317 #ifdef HAVE_MINGW
 318 # define setpriority(level) !SetPriorityClass(GetCurrentProcess(), (level))
 319
 320 static void stop_handler(void *data, int flags) {
 321         event_exit();
 322 }
 323
 324 static BOOL WINAPI console_ctrl_handler(DWORD type) {
 325         logger(DEBUG_ALWAYS, LOG_NOTICE, "Got console shutdown request");
 326         if (WSASetEvent(stop_io.event) == FALSE)
 327                 abort();
 328         return TRUE;
 329 }
 330 #else
 331 # define NORMAL_PRIORITY_CLASS 0
 332 # define BELOW_NORMAL_PRIORITY_CLASS 10
 333 # define HIGH_PRIORITY_CLASS -10
 334 # define setpriority(level) (setpriority(PRIO_PROCESS, 0, (level)))
 335 #endif
 336
 337 int main(int argc, char **argv) {
 338         program_name = argv[0];
 339
 340         if(!parse_options(argc, argv))
 341                 return 1;
 342
 343         make_names(true);
 344         chdir(confbase);
 345
 346         if(show_version) {
 347                 printf("%s version %s (built %s %s, protocol %d.%d)\n", PACKAGE,
 348                            BUILD_VERSION, BUILD_DATE, BUILD_TIME, PROT_MAJOR, PROT_MINOR);
 349                 printf("Copyright (C) 1998-2016 Ivo Timmermans, Guus Sliepen and others.\n"
 350                                 "See the AUTHORS file for a complete list.\n\n"
 351                                 "tinc comes with ABSOLUTELY NO WARRANTY.  This is free software,\n"
 352                                 "and you are welcome to redistribute it under certain conditions;\n"
 353                                 "see the file COPYING for details.\n");
 354
 355                 return 0;
 356         }
 357
 358         if(show_help) {
 359                 usage(false);
 360                 return 0;
 361         }
 362
 363 #ifdef HAVE_MINGW
 364         if(WSAStartup(MAKEWORD(2, 2), &wsa_state)) {
 365                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "WSAStartup", winerror(GetLastError()));
 366                 return 1;
 367         }
 368 #else
 369         // Check if we got an umbilical fd from the process that started us
 370         char *umbstr = getenv("TINC_UMBILICAL");
 371         if(umbstr) {
 372                 umbilical = atoi(umbstr);
 373                 if(fcntl(umbilical, F_GETFL) < 0)
 374                         umbilical = 0;
 375 #ifdef FD_CLOEXEC
 376                 if(umbilical)
 377                         fcntl(umbilical, F_SETFD, FD_CLOEXEC);
 378 #endif
 379         }
 380 #endif
 381
 382         openlogger("tinc", use_logfile?LOGMODE_FILE:LOGMODE_STDERR);
 383
 384         g_argv = argv;
 385
 386         if(getenv("LISTEN_PID") && atoi(getenv("LISTEN_PID")) == getpid())
 387                 do_detach = false;
 388 #ifdef HAVE_UNSETENV
 389         unsetenv("LISTEN_PID");
 390 #endif
 391
 392         init_configuration(&config_tree);
 393
 394         /* Slllluuuuuuurrrrp! */
 395
 396         gettimeofday(&now, NULL);
 397         srand(now.tv_sec + now.tv_usec);
 398         crypto_init();
 399
 400         if(!read_server_config())
 401                 return 1;
 402
 403 #ifdef HAVE_LZO
 404         if(lzo_init() != LZO_E_OK) {
 405                 logger(DEBUG_ALWAYS, LOG_ERR, "Error initializing LZO compressor!");
 406                 return 1;
 407         }
 408 #endif
 409
 410 #ifdef HAVE_MINGW
 411         io_add_event(&stop_io, stop_handler, NULL, WSACreateEvent());
 412         if (stop_io.event == FALSE)
 413                 abort();
 414
 415         int result;
 416         if(!do_detach || !init_service()) {
 417                 SetConsoleCtrlHandler(console_ctrl_handler, TRUE);
 418                 result = main2(argc, argv);
 419         } else
 420                 result = 1;
 421
 422         if (WSACloseEvent(stop_io.event) == FALSE)
 423                 abort();
 424         io_del(&stop_io);
 425         return result;
 426 }
 427
 428 int main2(int argc, char **argv) {
 429 #endif
 430         char *priority = NULL;
 431
 432         if(!detach())
 433                 return 1;
 434
 435 #ifdef HAVE_MLOCKALL
 436         /* Lock all pages into memory if requested.
 437          * This has to be done after daemon()/fork() so it works for child.
 438          * No need to do that in parent as it's very short-lived. */
 439         if(do_mlock && mlockall(MCL_CURRENT | MCL_FUTURE) != 0) {
 440                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "mlockall",
 441                    strerror(errno));
 442                 return 1;
 443         }
 444 #endif
 445
 446         /* Setup sockets and open device. */
 447
 448         if(!setup_network())
 449                 goto end;
 450
 451         /* Change process priority */
 452
 453         if(get_config_string(lookup_config(config_tree, "ProcessPriority"), &priority)) {
 454                 if(!strcasecmp(priority, "Normal")) {
 455                         if (setpriority(NORMAL_PRIORITY_CLASS) != 0) {
 456                                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setpriority", strerror(errno));
 457                                 goto end;
 458                         }
 459                 } else if(!strcasecmp(priority, "Low")) {
 460                         if (setpriority(BELOW_NORMAL_PRIORITY_CLASS) != 0) {
 461                                        logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setpriority", strerror(errno));
 462                                 goto end;
 463                         }
 464                 } else if(!strcasecmp(priority, "High")) {
 465                         if (setpriority(HIGH_PRIORITY_CLASS) != 0) {
 466                                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setpriority", strerror(errno));
 467                                 goto end;
 468                         }
 469                 } else {
 470                         logger(DEBUG_ALWAYS, LOG_ERR, "Invalid priority `%s`!", priority);
 471                         goto end;
 472                 }
 473         }
 474
 475         /* drop privileges */
 476         if (!drop_privs())
 477                 goto end;
 478
 479         /* Start main loop. It only exits when tinc is killed. */
 480
 481         logger(DEBUG_ALWAYS, LOG_NOTICE, "Ready");
 482
 483         if(umbilical) { // snip!
 484                 write(umbilical, "", 1);
 485                 close(umbilical);
 486                 umbilical = 0;
 487         }
 488
 489         try_outgoing_connections();
 490
 491         status = main_loop();
 492
 493         /* Shutdown properly. */
 494
 495 end:
 496         close_network_connections();
 497
 498         logger(DEBUG_ALWAYS, LOG_NOTICE, "Terminating");
 499
 500         free(priority);
 501
 502         crypto_exit();
 503
 504         exit_configuration(&config_tree);
 505         free(cmdline_conf);
 506         free_names();
 507
 508         return status;
 509 }