www.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                   2000-2017 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 #include <openssl/rand.h>
  37 #include <openssl/rsa.h>
  38 #include <openssl/pem.h>
  39 #include <openssl/evp.h>
  40 #include <openssl/engine.h>
  41
  42 #ifdef HAVE_LZO
  43 #include LZO1X_H
  44 #endif
  45
  46 #ifndef HAVE_MINGW
  47 #include <pwd.h>
  48 #include <grp.h>
  49 #include <time.h>
  50 #endif
  51
  52 #ifdef HAVE_GETOPT_LONG
  53 #include <getopt.h>
  54 #else
  55 #include "getopt.h"
  56 #endif
  57
  58 #include "pidfile.h"
  59
  60 #include "conf.h"
  61 #include "device.h"
  62 #include "logger.h"
  63 #include "net.h"
  64 #include "netutl.h"
  65 #include "process.h"
  66 #include "protocol.h"
  67 #include "utils.h"
  68 #include "xalloc.h"
  69
  70 /* The name this program was run with. */
  71 char *program_name = NULL;
  72
  73 /* If nonzero, display usage information and exit. */
  74 bool show_help = false;
  75
  76 /* If nonzero, print the version on standard output and exit.  */
  77 bool show_version = false;
  78
  79 /* If nonzero, it will attempt to kill a running tincd and exit. */
  80 int kill_tincd = 0;
  81
  82 /* If nonzero, generate public/private keypair for this host/net. */
  83 int generate_keys = 0;
  84
  85 /* If nonzero, use null ciphers and skip all key exchanges. */
  86 bool bypass_security = false;
  87
  88 /* If nonzero, disable swapping for this process. */
  89 bool do_mlock = false;
  90
  91 /* If nonzero, chroot to netdir after startup. */
  92 static bool do_chroot = false;
  93
  94 /* If !NULL, do setuid to given user after startup */
  95 static const char *switchuser = NULL;
  96
  97 /* If nonzero, write log entries to a separate file. */
  98 bool use_logfile = false;
  99
 100 char *identname = NULL;                         /* program name for syslog */
 101 char *pidfilename = NULL;                       /* pid file location */
 102 char *logfilename = NULL;                       /* log file location */
 103 char **g_argv;                                  /* a copy of the cmdline arguments */
 104
 105 static int status = 1;
 106
 107 static struct option const long_options[] = {
 108         {"config", required_argument, NULL, 'c'},
 109         {"kill", optional_argument, NULL, 'k'},
 110         {"net", required_argument, NULL, 'n'},
 111         {"help", no_argument, NULL, 1},
 112         {"version", no_argument, NULL, 2},
 113         {"no-detach", no_argument, NULL, 'D'},
 114         {"generate-keys", optional_argument, NULL, 'K'},
 115         {"debug", optional_argument, NULL, 'd'},
 116         {"bypass-security", no_argument, NULL, 3},
 117         {"mlock", no_argument, NULL, 'L'},
 118         {"chroot", no_argument, NULL, 'R'},
 119         {"user", required_argument, NULL, 'U'},
 120         {"logfile", optional_argument, NULL, 4},
 121         {"pidfile", required_argument, NULL, 5},
 122         {"option", required_argument, NULL, 'o'},
 123         {NULL, 0, NULL, 0}
 124 };
 125
 126 #ifdef HAVE_MINGW
 127 static struct WSAData wsa_state;
 128 CRITICAL_SECTION mutex;
 129 int main2(int argc, char **argv);
 130 #endif
 131
 132 static void usage(bool status) {
 133         if(status)
 134                 fprintf(stderr, "Try `%s --help\' for more information.\n",
 135                                 program_name);
 136         else {
 137                 printf("Usage: %s [option]...\n\n", program_name);
 138                 printf("  -c, --config=DIR               Read configuration options from DIR.\n"
 139                                 "  -D, --no-detach                Don't fork and detach.\n"
 140                                 "  -d, --debug[=LEVEL]            Increase debug level or set it to LEVEL.\n"
 141                                 "  -k, --kill[=SIGNAL]            Attempt to kill a running tincd and exit.\n"
 142                                 "  -n, --net=NETNAME              Connect to net NETNAME.\n"
 143                                 "  -K, --generate-keys[=BITS]     Generate public/private RSA keypair.\n"
 144                                 "  -L, --mlock                    Lock tinc into main memory.\n"
 145                                 "      --logfile[=FILENAME]       Write log entries to a logfile.\n"
 146                                 "      --pidfile=FILENAME         Write PID to FILENAME.\n"
 147                                 "  -o, --option=[HOST.]KEY=VALUE  Set global/host configuration value.\n"
 148                                 "  -R, --chroot                   chroot to NET dir at startup.\n"
 149                                 "  -U, --user=USER                setuid to given USER at startup.\n"
 150                                 "      --help                     Display this help and exit.\n"
 151                                 "      --version                  Output version information and exit.\n\n");
 152                 printf("Report bugs to tinc@tinc-vpn.org.\n");
 153         }
 154 }
 155
 156 static bool parse_options(int argc, char **argv) {
 157         config_t *cfg;
 158         int r;
 159         int option_index = 0;
 160         int lineno = 0;
 161
 162         cmdline_conf = list_alloc((list_action_t)free_config);
 163
 164         while((r = getopt_long(argc, argv, "c:DLd::k::n:o:K::RU:", long_options, &option_index)) != EOF) {
 165                 switch (r) {
 166                         case 0:                         /* long option */
 167                                 break;
 168
 169                         case 'c':                               /* config file */
 170                                 if(confbase) {
 171                                         fprintf(stderr, "Only one configuration directory can be given.\n");
 172                                         usage(true);
 173                                         return false;
 174                                 }
 175                                 confbase = xstrdup(optarg);
 176                                 break;
 177
 178                         case 'D':                               /* no detach */
 179                                 do_detach = false;
 180                                 break;
 181
 182                         case 'L':                               /* no detach */
 183 #ifndef HAVE_MLOCKALL
 184                                 logger(LOG_ERR, "%s not supported on this platform", "mlockall()");
 185                                 return false;
 186 #else
 187                                 do_mlock = true;
 188                                 break;
 189 #endif
 190
 191                         case 'd':                               /* increase debug level */
 192                                 if(!optarg && optind < argc && *argv[optind] != '-')
 193                                         optarg = argv[optind++];
 194                                 if(optarg)
 195                                         debug_level = atoi(optarg);
 196                                 else
 197                                         debug_level++;
 198                                 break;
 199
 200                         case 'k':                               /* kill old tincds */
 201 #ifndef HAVE_MINGW
 202                                 if(!optarg && optind < argc && *argv[optind] != '-')
 203                                         optarg = argv[optind++];
 204                                 if(optarg) {
 205                                         if(!strcasecmp(optarg, "HUP"))
 206                                                 kill_tincd = SIGHUP;
 207                                         else if(!strcasecmp(optarg, "TERM"))
 208                                                 kill_tincd = SIGTERM;
 209                                         else if(!strcasecmp(optarg, "KILL"))
 210                                                 kill_tincd = SIGKILL;
 211                                         else if(!strcasecmp(optarg, "USR1"))
 212                                                 kill_tincd = SIGUSR1;
 213                                         else if(!strcasecmp(optarg, "USR2"))
 214                                                 kill_tincd = SIGUSR2;
 215                                         else if(!strcasecmp(optarg, "WINCH"))
 216                                                 kill_tincd = SIGWINCH;
 217                                         else if(!strcasecmp(optarg, "INT"))
 218                                                 kill_tincd = SIGINT;
 219                                         else if(!strcasecmp(optarg, "ALRM"))
 220                                                 kill_tincd = SIGALRM;
 221                                         else if(!strcasecmp(optarg, "ABRT"))
 222                                                 kill_tincd = SIGABRT;
 223                                         else {
 224                                                 kill_tincd = atoi(optarg);
 225
 226                                                 if(!kill_tincd) {
 227                                                         fprintf(stderr, "Invalid argument `%s'; SIGNAL must be a number or one of HUP, TERM, KILL, USR1, USR2, WINCH, INT or ALRM.\n",
 228                                                                         optarg);
 229                                                         usage(true);
 230                                                         return false;
 231                                                 }
 232                                         }
 233                                 } else
 234                                         kill_tincd = SIGTERM;
 235 #else
 236                                         kill_tincd = 1;
 237 #endif
 238                                 break;
 239
 240                         case 'n':                               /* net name given */
 241                                 /* netname "." is special: a "top-level name" */
 242                                 if(netname) {
 243                                         fprintf(stderr, "Only one netname can be given.\n");
 244                                         usage(true);
 245                                         return false;
 246                                 }
 247                                 if(optarg && strcmp(optarg, "."))
 248                                         netname = xstrdup(optarg);
 249                                 break;
 250
 251                         case 'o':                               /* option */
 252                                 cfg = parse_config_line(optarg, NULL, ++lineno);
 253                                 if (!cfg)
 254                                         return false;
 255                                 list_insert_tail(cmdline_conf, cfg);
 256                                 break;
 257
 258                         case 'K':                               /* generate public/private keypair */
 259                                 if(!optarg && optind < argc && *argv[optind] != '-')
 260                                         optarg = argv[optind++];
 261                                 if(optarg) {
 262                                         generate_keys = atoi(optarg);
 263
 264                                         if(generate_keys < 512) {
 265                                                 fprintf(stderr, "Invalid argument `%s'; BITS must be a number equal to or greater than 512.\n",
 266                                                                 optarg);
 267                                                 usage(true);
 268                                                 return false;
 269                                         }
 270
 271                                         generate_keys &= ~7;    /* Round it to bytes */
 272                                 } else
 273                                         generate_keys = 2048;
 274                                 break;
 275
 276                         case 'R':                               /* chroot to NETNAME dir */
 277                                 do_chroot = true;
 278                                 break;
 279
 280                         case 'U':                               /* setuid to USER */
 281                                 switchuser = optarg;
 282                                 break;
 283
 284                         case 1:                                 /* show help */
 285                                 show_help = true;
 286                                 break;
 287
 288                         case 2:                                 /* show version */
 289                                 show_version = true;
 290                                 break;
 291
 292                         case 3:                                 /* bypass security */
 293                                 bypass_security = true;
 294                                 break;
 295
 296                         case 4:                                 /* write log entries to a file */
 297                                 use_logfile = true;
 298                                 if(!optarg && optind < argc && *argv[optind] != '-')
 299                                         optarg = argv[optind++];
 300                                 if(optarg) {
 301                                         if(logfilename) {
 302                                                 fprintf(stderr, "Only one logfile can be given.\n");
 303                                                 usage(true);
 304                                                 return false;
 305                                         }
 306                                         logfilename = xstrdup(optarg);
 307                                 }
 308                                 break;
 309
 310                         case 5:                                 /* write PID to a file */
 311                                 if(pidfilename) {
 312                                         fprintf(stderr, "Only one pidfile can be given.\n");
 313                                         usage(true);
 314                                         return false;
 315                                 }
 316                                 pidfilename = xstrdup(optarg);
 317                                 break;
 318
 319                         case '?':
 320                                 usage(true);
 321                                 return false;
 322
 323                         default:
 324                                 break;
 325                 }
 326         }
 327
 328         if(optind < argc) {
 329                 fprintf(stderr, "%s: unrecognized argument '%s'\n", argv[0], argv[optind]);
 330                 usage(true);
 331                 return false;
 332         }
 333
 334         return true;
 335 }
 336
 337 /* This function prettyprints the key generation process */
 338
 339 static int indicator(int a, int b, BN_GENCB *cb) {
 340         switch (a) {
 341                 case 0:
 342                         fprintf(stderr, ".");
 343                         break;
 344
 345                 case 1:
 346                         fprintf(stderr, "+");
 347                         break;
 348
 349                 case 2:
 350                         fprintf(stderr, "-");
 351                         break;
 352
 353                 case 3:
 354                         switch (b) {
 355                                 case 0:
 356                                         fprintf(stderr, " p\n");
 357                                         break;
 358
 359                                 case 1:
 360                                         fprintf(stderr, " q\n");
 361                                         break;
 362
 363                                 default:
 364                                         fprintf(stderr, "?");
 365                         }
 366                         break;
 367
 368                 default:
 369                         fprintf(stderr, "?");
 370         }
 371
 372         return 1;
 373 }
 374
 375 #ifndef HAVE_BN_GENCB_NEW
 376 BN_GENCB *BN_GENCB_new(void) {
 377         return xmalloc_and_zero(sizeof(BN_GENCB));
 378 }
 379
 380 void BN_GENCB_free(BN_GENCB *cb) {
 381         free(cb);
 382 }
 383 #endif
 384
 385 /*
 386   Generate a public/private RSA keypair, and ask for a file to store
 387   them in.
 388 */
 389 static bool keygen(int bits) {
 390         BIGNUM *e = NULL;
 391         RSA *rsa_key;
 392         FILE *f;
 393         char filename[PATH_MAX];
 394         BN_GENCB *cb;
 395         int result;
 396
 397         fprintf(stderr, "Generating %d bits keys:\n", bits);
 398
 399         cb = BN_GENCB_new();
 400         if(!cb)
 401                 abort();
 402         BN_GENCB_set(cb, indicator, NULL);
 403
 404         rsa_key = RSA_new();
 405         BN_hex2bn(&e, "10001");
 406         if(!rsa_key || !e)
 407                 abort();
 408
 409         result = RSA_generate_key_ex(rsa_key, bits, e, cb);
 410
 411         BN_free(e);
 412         BN_GENCB_free(cb);
 413
 414         if(!result) {
 415                 fprintf(stderr, "Error during key generation!\n");
 416                 RSA_free(rsa_key);
 417                 return false;
 418         } else
 419                 fprintf(stderr, "Done.\n");
 420
 421         snprintf(filename, sizeof(filename), "%s/rsa_key.priv", confbase);
 422         f = ask_and_open(filename, "private RSA key");
 423
 424         if(!f) {
 425                 RSA_free(rsa_key);
 426                 return false;
 427         }
 428
 429 #ifdef HAVE_FCHMOD
 430         /* Make it unreadable for others. */
 431         fchmod(fileno(f), 0600);
 432 #endif
 433
 434         fputc('\n', f);
 435         PEM_write_RSAPrivateKey(f, rsa_key, NULL, NULL, 0, NULL, NULL);
 436         fclose(f);
 437
 438         char *name = get_name();
 439
 440         if(name) {
 441                 snprintf(filename, sizeof(filename), "%s/hosts/%s", confbase, name);
 442                 free(name);
 443         } else {
 444                 snprintf(filename, sizeof(filename), "%s/rsa_key.pub", confbase);
 445         }
 446
 447         f = ask_and_open(filename, "public RSA key");
 448
 449         if(!f) {
 450                 RSA_free(rsa_key);
 451                 return false;
 452         }
 453
 454         fputc('\n', f);
 455         PEM_write_RSAPublicKey(f, rsa_key);
 456         fclose(f);
 457
 458         RSA_free(rsa_key);
 459
 460         return true;
 461 }
 462
 463 /*
 464   Set all files and paths according to netname
 465 */
 466 static void make_names(void) {
 467 #ifdef HAVE_MINGW
 468         HKEY key;
 469         char installdir[1024] = "";
 470         DWORD len = sizeof(installdir);
 471 #endif
 472
 473         if(netname)
 474                 xasprintf(&identname, "tinc.%s", netname);
 475         else
 476                 identname = xstrdup("tinc");
 477
 478 #ifdef HAVE_MINGW
 479         if(!RegOpenKeyEx(HKEY_LOCAL_MACHINE, "SOFTWARE\\tinc", 0, KEY_READ, &key)) {
 480                 if(!RegQueryValueEx(key, NULL, 0, 0, (LPBYTE)installdir, &len)) {
 481                         if(!confbase) {
 482                                 if(netname)
 483                                         xasprintf(&confbase, "%s/%s", installdir, netname);
 484                                 else
 485                                         xasprintf(&confbase, "%s", installdir);
 486                         }
 487                         if(!logfilename)
 488                                 xasprintf(&logfilename, "%s/tinc.log", confbase);
 489                 }
 490                 RegCloseKey(key);
 491                 if(*installdir)
 492                         return;
 493         }
 494 #endif
 495
 496         if(!pidfilename)
 497                 xasprintf(&pidfilename, LOCALSTATEDIR "/run/%s.pid", identname);
 498
 499         if(!logfilename)
 500                 xasprintf(&logfilename, LOCALSTATEDIR "/log/%s.log", identname);
 501
 502         if(netname) {
 503                 if(!confbase)
 504                         xasprintf(&confbase, CONFDIR "/tinc/%s", netname);
 505                 else
 506                         logger(LOG_INFO, "Both netname and configuration directory given, using the latter...");
 507         } else {
 508                 if(!confbase)
 509                         xasprintf(&confbase, CONFDIR "/tinc");
 510         }
 511 }
 512
 513 static void free_names() {
 514         if (identname) free(identname);
 515         if (netname) free(netname);
 516         if (pidfilename) free(pidfilename);
 517         if (logfilename) free(logfilename);
 518         if (confbase) free(confbase);
 519 }
 520
 521 static bool drop_privs() {
 522 #ifdef HAVE_MINGW
 523         if (switchuser) {
 524                 logger(LOG_ERR, "%s not supported on this platform", "-U");
 525                 return false;
 526         }
 527         if (do_chroot) {
 528                 logger(LOG_ERR, "%s not supported on this platform", "-R");
 529                 return false;
 530         }
 531 #else
 532         uid_t uid = 0;
 533         if (switchuser) {
 534                 struct passwd *pw = getpwnam(switchuser);
 535                 if (!pw) {
 536                         logger(LOG_ERR, "unknown user `%s'", switchuser);
 537                         return false;
 538                 }
 539                 uid = pw->pw_uid;
 540                 if (initgroups(switchuser, pw->pw_gid) != 0 ||
 541                     setgid(pw->pw_gid) != 0) {
 542                         logger(LOG_ERR, "System call `%s' failed: %s",
 543                                "initgroups", strerror(errno));
 544                         return false;
 545                 }
 546 #ifndef ANDROID
 547 // Not supported in android NDK
 548                 endgrent();
 549                 endpwent();
 550 #endif
 551         }
 552         if (do_chroot) {
 553                 tzset();        /* for proper timestamps in logs */
 554                 if (chroot(confbase) != 0 || chdir("/") != 0) {
 555                         logger(LOG_ERR, "System call `%s' failed: %s",
 556                                "chroot", strerror(errno));
 557                         return false;
 558                 }
 559                 free(confbase);
 560                 confbase = xstrdup("");
 561         }
 562         if (switchuser)
 563                 if (setuid(uid) != 0) {
 564                         logger(LOG_ERR, "System call `%s' failed: %s",
 565                                "setuid", strerror(errno));
 566                         return false;
 567                 }
 568 #endif
 569         return true;
 570 }
 571
 572 #ifdef HAVE_MINGW
 573 # define setpriority(level) !SetPriorityClass(GetCurrentProcess(), (level))
 574 #else
 575 # define NORMAL_PRIORITY_CLASS 0
 576 # define BELOW_NORMAL_PRIORITY_CLASS 10
 577 # define HIGH_PRIORITY_CLASS -10
 578 # define setpriority(level) (setpriority(PRIO_PROCESS, 0, (level)))
 579 #endif
 580
 581 int main(int argc, char **argv) {
 582         program_name = argv[0];
 583
 584         if(!parse_options(argc, argv))
 585                 return 1;
 586
 587         make_names();
 588
 589         if(show_version) {
 590                 printf("%s version %s\n", PACKAGE, VERSION);
 591                 printf("Copyright (C) 1998-2017 Ivo Timmermans, Guus Sliepen and others.\n"
 592                                 "See the AUTHORS file for a complete list.\n\n"
 593                                 "tinc comes with ABSOLUTELY NO WARRANTY.  This is free software,\n"
 594                                 "and you are welcome to redistribute it under certain conditions;\n"
 595                                 "see the file COPYING for details.\n");
 596
 597                 return 0;
 598         }
 599
 600         if(show_help) {
 601                 usage(false);
 602                 return 0;
 603         }
 604
 605         if(kill_tincd)
 606                 return !kill_other(kill_tincd);
 607
 608         openlogger("tinc", use_logfile?LOGMODE_FILE:LOGMODE_STDERR);
 609
 610         g_argv = argv;
 611
 612         if(getenv("LISTEN_PID") && atoi(getenv("LISTEN_PID")) == getpid())
 613                 do_detach = false;
 614 #ifdef HAVE_UNSETENV
 615         unsetenv("LISTEN_PID");
 616 #endif
 617
 618         init_configuration(&config_tree);
 619
 620         /* Slllluuuuuuurrrrp! */
 621
 622         RAND_load_file("/dev/urandom", 1024);
 623
 624         ENGINE_load_builtin_engines();
 625         ENGINE_register_all_complete();
 626
 627         OpenSSL_add_all_algorithms();
 628
 629         if(generate_keys) {
 630                 read_server_config();
 631                 return !keygen(generate_keys);
 632         }
 633
 634         if(!read_server_config())
 635                 return 1;
 636
 637 #ifdef HAVE_LZO
 638         if(lzo_init() != LZO_E_OK) {
 639                 logger(LOG_ERR, "Error initializing LZO compressor!");
 640                 return 1;
 641         }
 642 #endif
 643
 644 #ifdef HAVE_MINGW
 645         if(WSAStartup(MAKEWORD(2, 2), &wsa_state)) {
 646                 logger(LOG_ERR, "System call `%s' failed: %s", "WSAStartup", winerror(GetLastError()));
 647                 return 1;
 648         }
 649
 650         if(!do_detach || !init_service())
 651                 return main2(argc, argv);
 652         else
 653                 return 1;
 654 }
 655
 656 int main2(int argc, char **argv) {
 657         InitializeCriticalSection(&mutex);
 658         EnterCriticalSection(&mutex);
 659 #endif
 660         char *priority = NULL;
 661
 662         if(!detach())
 663                 return 1;
 664
 665 #ifdef HAVE_MLOCKALL
 666         /* Lock all pages into memory if requested.
 667          * This has to be done after daemon()/fork() so it works for child.
 668          * No need to do that in parent as it's very short-lived. */
 669         if(do_mlock && mlockall(MCL_CURRENT | MCL_FUTURE) != 0) {
 670                 logger(LOG_ERR, "System call `%s' failed: %s", "mlockall",
 671                    strerror(errno));
 672                 return 1;
 673         }
 674 #endif
 675
 676         /* Setup sockets and open device. */
 677
 678         if(!setup_network())
 679                 goto end;
 680
 681         /* Initiate all outgoing connections. */
 682
 683         try_outgoing_connections();
 684
 685         /* Change process priority */
 686
 687         if(get_config_string(lookup_config(config_tree, "ProcessPriority"), &priority)) {
 688                 if(!strcasecmp(priority, "Normal")) {
 689                         if (setpriority(NORMAL_PRIORITY_CLASS) != 0) {
 690                                 logger(LOG_ERR, "System call `%s' failed: %s",
 691                                        "setpriority", strerror(errno));
 692                                 goto end;
 693                         }
 694                 } else if(!strcasecmp(priority, "Low")) {
 695                         if (setpriority(BELOW_NORMAL_PRIORITY_CLASS) != 0) {
 696                                        logger(LOG_ERR, "System call `%s' failed: %s",
 697                                        "setpriority", strerror(errno));
 698                                 goto end;
 699                         }
 700                 } else if(!strcasecmp(priority, "High")) {
 701                         if (setpriority(HIGH_PRIORITY_CLASS) != 0) {
 702                                 logger(LOG_ERR, "System call `%s' failed: %s",
 703                                        "setpriority", strerror(errno));
 704                                 goto end;
 705                         }
 706                 } else {
 707                         logger(LOG_ERR, "Invalid priority `%s`!", priority);
 708                         goto end;
 709                 }
 710         }
 711
 712         /* drop privileges */
 713         if (!drop_privs())
 714                 goto end;
 715
 716         /* Start main loop. It only exits when tinc is killed. */
 717
 718         status = main_loop();
 719
 720         /* Shutdown properly. */
 721
 722         ifdebug(CONNECTIONS)
 723                 devops.dump_stats();
 724
 725         close_network_connections();
 726
 727 end:
 728         logger(LOG_NOTICE, "Terminating");
 729
 730 #ifndef HAVE_MINGW
 731         remove_pid(pidfilename);
 732 #endif
 733
 734         free(priority);
 735
 736         EVP_cleanup();
 737         ENGINE_cleanup();
 738         CRYPTO_cleanup_all_ex_data();
 739 #ifdef HAVE_ERR_REMOVE_STATE
 740         // OpenSSL claims this function was deprecated in 1.0.0,
 741         // but valgrind's leak detector shows you still need to call it to make sure OpenSSL cleans up properly.
 742         ERR_remove_state(0);
 743 #endif
 744         ERR_free_strings();
 745
 746         exit_configuration(&config_tree);
 747         list_delete_list(cmdline_conf);
 748         free_names();
 749
 750         return status;
 751 }