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                   2000-2018 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 #ifndef OPENSSL_NO_ENGINE
  41 #include <openssl/engine.h>
  42 #endif
  43
  44 #ifdef HAVE_LZO
  45 #include LZO1X_H
  46 #endif
  47
  48 #ifndef HAVE_MINGW
  49 #include <pwd.h>
  50 #include <grp.h>
  51 #include <time.h>
  52 #endif
  53
  54 #ifdef HAVE_GETOPT_LONG
  55 #include <getopt.h>
  56 #else
  57 #include "getopt.h"
  58 #endif
  59
  60 #include "pidfile.h"
  61
  62 #include "conf.h"
  63 #include "device.h"
  64 #include "logger.h"
  65 #include "net.h"
  66 #include "netutl.h"
  67 #include "process.h"
  68 #include "protocol.h"
  69 #include "utils.h"
  70 #include "xalloc.h"
  71
  72 /* The name this program was run with. */
  73 char *program_name = NULL;
  74
  75 /* If nonzero, display usage information and exit. */
  76 bool show_help = false;
  77
  78 /* If nonzero, print the version on standard output and exit.  */
  79 bool show_version = false;
  80
  81 /* If nonzero, it will attempt to kill a running tincd and exit. */
  82 int kill_tincd = 0;
  83
  84 /* If nonzero, generate public/private keypair for this host/net. */
  85 int generate_keys = 0;
  86
  87 /* If nonzero, use null ciphers and skip all key exchanges. */
  88 bool bypass_security = false;
  89
  90 /* If nonzero, disable swapping for this process. */
  91 bool do_mlock = false;
  92
  93 /* If nonzero, chroot to netdir after startup. */
  94 static bool do_chroot = false;
  95
  96 /* If !NULL, do setuid to given user after startup */
  97 static const char *switchuser = NULL;
  98
  99 /* If nonzero, write log entries to a separate file. */
 100 bool use_logfile = false;
 101
 102 char *identname = NULL;                         /* program name for syslog */
 103 char *pidfilename = NULL;                       /* pid file location */
 104 char *logfilename = NULL;                       /* log file location */
 105 char **g_argv;                                  /* a copy of the cmdline arguments */
 106
 107 static int status = 1;
 108
 109 static struct option const long_options[] = {
 110         {"config", required_argument, NULL, 'c'},
 111         {"kill", optional_argument, NULL, 'k'},
 112         {"net", required_argument, NULL, 'n'},
 113         {"help", no_argument, NULL, 1},
 114         {"version", no_argument, NULL, 2},
 115         {"no-detach", no_argument, NULL, 'D'},
 116         {"generate-keys", optional_argument, NULL, 'K'},
 117         {"debug", optional_argument, NULL, 'd'},
 118         {"bypass-security", no_argument, NULL, 3},
 119         {"mlock", no_argument, NULL, 'L'},
 120         {"chroot", no_argument, NULL, 'R'},
 121         {"user", required_argument, NULL, 'U'},
 122         {"logfile", optional_argument, NULL, 4},
 123         {"pidfile", required_argument, NULL, 5},
 124         {"option", required_argument, NULL, 'o'},
 125         {NULL, 0, NULL, 0}
 126 };
 127
 128 #ifdef HAVE_MINGW
 129 static struct WSAData wsa_state;
 130 CRITICAL_SECTION mutex;
 131 int main2(int argc, char **argv);
 132 #endif
 133
 134 static void usage(bool status) {
 135         if(status)
 136                 fprintf(stderr, "Try `%s --help\' for more information.\n",
 137                         program_name);
 138         else {
 139                 printf("Usage: %s [option]...\n\n", program_name);
 140                 printf("  -c, --config=DIR               Read configuration options from DIR.\n"
 141                        "  -D, --no-detach                Don't fork and detach.\n"
 142                        "  -d, --debug[=LEVEL]            Increase debug level or set it to LEVEL.\n"
 143                        "  -k, --kill[=SIGNAL]            Attempt to kill a running tincd and exit.\n"
 144                        "  -n, --net=NETNAME              Connect to net NETNAME.\n"
 145                        "  -K, --generate-keys[=BITS]     Generate public/private RSA keypair.\n"
 146                        "  -L, --mlock                    Lock tinc into main memory.\n"
 147                        "      --logfile[=FILENAME]       Write log entries to a logfile.\n"
 148                        "      --pidfile=FILENAME         Write PID to FILENAME.\n"
 149                        "  -o, --option=[HOST.]KEY=VALUE  Set global/host configuration value.\n"
 150                        "  -R, --chroot                   chroot to NET dir at startup.\n"
 151                        "  -U, --user=USER                setuid to given USER at startup.\n"
 152                        "      --help                     Display this help and exit.\n"
 153                        "      --version                  Output version information and exit.\n\n");
 154                 printf("Report bugs to tinc@tinc-vpn.org.\n");
 155         }
 156 }
 157
 158 static bool parse_options(int argc, char **argv) {
 159         config_t *cfg;
 160         int r;
 161         int option_index = 0;
 162         int lineno = 0;
 163
 164         cmdline_conf = list_alloc((list_action_t)free_config);
 165
 166         while((r = getopt_long(argc, argv, "c:DLd::k::n:o:K::RU:", long_options, &option_index)) != EOF) {
 167                 switch(r) {
 168                 case 0:                         /* long option */
 169                         break;
 170
 171                 case 'c':                               /* config file */
 172                         if(confbase) {
 173                                 fprintf(stderr, "Only one configuration directory can be given.\n");
 174                                 usage(true);
 175                                 return false;
 176                         }
 177
 178                         confbase = xstrdup(optarg);
 179                         break;
 180
 181                 case 'D':                               /* no detach */
 182                         do_detach = false;
 183                         break;
 184
 185                 case 'L':                               /* no detach */
 186 #ifndef HAVE_MLOCKALL
 187                         logger(LOG_ERR, "%s not supported on this platform", "mlockall()");
 188                         return false;
 189 #else
 190                         do_mlock = true;
 191                         break;
 192 #endif
 193
 194                 case 'd':                               /* increase debug level */
 195                         if(!optarg && optind < argc && *argv[optind] != '-') {
 196                                 optarg = argv[optind++];
 197                         }
 198
 199                         if(optarg) {
 200                                 debug_level = atoi(optarg);
 201                         } else {
 202                                 debug_level++;
 203                         }
 204
 205                         break;
 206
 207                 case 'k':                               /* kill old tincds */
 208 #ifndef HAVE_MINGW
 209                         if(!optarg && optind < argc && *argv[optind] != '-') {
 210                                 optarg = argv[optind++];
 211                         }
 212
 213                         if(optarg) {
 214                                 if(!strcasecmp(optarg, "HUP")) {
 215                                         kill_tincd = SIGHUP;
 216                                 } else if(!strcasecmp(optarg, "TERM")) {
 217                                         kill_tincd = SIGTERM;
 218                                 } else if(!strcasecmp(optarg, "KILL")) {
 219                                         kill_tincd = SIGKILL;
 220                                 } else if(!strcasecmp(optarg, "USR1")) {
 221                                         kill_tincd = SIGUSR1;
 222                                 } else if(!strcasecmp(optarg, "USR2")) {
 223                                         kill_tincd = SIGUSR2;
 224                                 } else if(!strcasecmp(optarg, "WINCH")) {
 225                                         kill_tincd = SIGWINCH;
 226                                 } else if(!strcasecmp(optarg, "INT")) {
 227                                         kill_tincd = SIGINT;
 228                                 } else if(!strcasecmp(optarg, "ALRM")) {
 229                                         kill_tincd = SIGALRM;
 230                                 } else if(!strcasecmp(optarg, "ABRT")) {
 231                                         kill_tincd = SIGABRT;
 232                                 } else {
 233                                         kill_tincd = atoi(optarg);
 234
 235                                         if(!kill_tincd) {
 236                                                 fprintf(stderr, "Invalid argument `%s'; SIGNAL must be a number or one of HUP, TERM, KILL, USR1, USR2, WINCH, INT or ALRM.\n",
 237                                                         optarg);
 238                                                 usage(true);
 239                                                 return false;
 240                                         }
 241                                 }
 242                         } else {
 243                                 kill_tincd = SIGTERM;
 244                         }
 245
 246 #else
 247                         kill_tincd = 1;
 248 #endif
 249                         break;
 250
 251                 case 'n':                               /* net name given */
 252
 253                         /* netname "." is special: a "top-level name" */
 254                         if(netname) {
 255                                 fprintf(stderr, "Only one netname can be given.\n");
 256                                 usage(true);
 257                                 return false;
 258                         }
 259
 260                         if(optarg && strcmp(optarg, ".")) {
 261                                 netname = xstrdup(optarg);
 262                         }
 263
 264                         break;
 265
 266                 case 'o':                               /* option */
 267                         cfg = parse_config_line(optarg, NULL, ++lineno);
 268
 269                         if(!cfg) {
 270                                 return false;
 271                         }
 272
 273                         list_insert_tail(cmdline_conf, cfg);
 274                         break;
 275
 276                 case 'K':                               /* generate public/private keypair */
 277                         if(!optarg && optind < argc && *argv[optind] != '-') {
 278                                 optarg = argv[optind++];
 279                         }
 280
 281                         if(optarg) {
 282                                 generate_keys = atoi(optarg);
 283
 284                                 if(generate_keys < 512) {
 285                                         fprintf(stderr, "Invalid argument `%s'; BITS must be a number equal to or greater than 512.\n",
 286                                                 optarg);
 287                                         usage(true);
 288                                         return false;
 289                                 }
 290
 291                                 generate_keys &= ~7;    /* Round it to bytes */
 292                         } else {
 293                                 generate_keys = 2048;
 294                         }
 295
 296                         break;
 297
 298                 case 'R':                               /* chroot to NETNAME dir */
 299                         do_chroot = true;
 300                         break;
 301
 302                 case 'U':                               /* setuid to USER */
 303                         switchuser = optarg;
 304                         break;
 305
 306                 case 1:                                 /* show help */
 307                         show_help = true;
 308                         break;
 309
 310                 case 2:                                 /* show version */
 311                         show_version = true;
 312                         break;
 313
 314                 case 3:                                 /* bypass security */
 315                         bypass_security = true;
 316                         break;
 317
 318                 case 4:                                 /* write log entries to a file */
 319                         use_logfile = true;
 320
 321                         if(!optarg && optind < argc && *argv[optind] != '-') {
 322                                 optarg = argv[optind++];
 323                         }
 324
 325                         if(optarg) {
 326                                 if(logfilename) {
 327                                         fprintf(stderr, "Only one logfile can be given.\n");
 328                                         usage(true);
 329                                         return false;
 330                                 }
 331
 332                                 logfilename = xstrdup(optarg);
 333                         }
 334
 335                         break;
 336
 337                 case 5:                                 /* write PID to a file */
 338                         if(pidfilename) {
 339                                 fprintf(stderr, "Only one pidfile can be given.\n");
 340                                 usage(true);
 341                                 return false;
 342                         }
 343
 344                         pidfilename = xstrdup(optarg);
 345                         break;
 346
 347                 case '?':
 348                         usage(true);
 349                         return false;
 350
 351                 default:
 352                         break;
 353                 }
 354         }
 355
 356         if(optind < argc) {
 357                 fprintf(stderr, "%s: unrecognized argument '%s'\n", argv[0], argv[optind]);
 358                 usage(true);
 359                 return false;
 360         }
 361
 362         return true;
 363 }
 364
 365 /* This function prettyprints the key generation process */
 366
 367 static int indicator(int a, int b, BN_GENCB *cb) {
 368         (void)cb;
 369
 370         switch(a) {
 371         case 0:
 372                 fprintf(stderr, ".");
 373                 break;
 374
 375         case 1:
 376                 fprintf(stderr, "+");
 377                 break;
 378
 379         case 2:
 380                 fprintf(stderr, "-");
 381                 break;
 382
 383         case 3:
 384                 switch(b) {
 385                 case 0:
 386                         fprintf(stderr, " p\n");
 387                         break;
 388
 389                 case 1:
 390                         fprintf(stderr, " q\n");
 391                         break;
 392
 393                 default:
 394                         fprintf(stderr, "?");
 395                 }
 396
 397                 break;
 398
 399         default:
 400                 fprintf(stderr, "?");
 401         }
 402
 403         return 1;
 404 }
 405
 406 #ifndef HAVE_BN_GENCB_NEW
 407 BN_GENCB *BN_GENCB_new(void) {
 408         return xmalloc_and_zero(sizeof(BN_GENCB));
 409 }
 410
 411 void BN_GENCB_free(BN_GENCB *cb) {
 412         free(cb);
 413 }
 414 #endif
 415
 416 /*
 417   Generate a public/private RSA keypair, and ask for a file to store
 418   them in.
 419 */
 420 static bool keygen(int bits) {
 421         BIGNUM *e = NULL;
 422         RSA *rsa_key;
 423         FILE *f;
 424         char filename[PATH_MAX];
 425         BN_GENCB *cb;
 426         int result;
 427
 428         fprintf(stderr, "Generating %d bits keys:\n", bits);
 429
 430         cb = BN_GENCB_new();
 431
 432         if(!cb) {
 433                 abort();
 434         }
 435
 436         BN_GENCB_set(cb, indicator, NULL);
 437
 438         rsa_key = RSA_new();
 439
 440         if(BN_hex2bn(&e, "10001") == 0) {
 441                 abort();
 442         }
 443
 444         if(!rsa_key || !e) {
 445                 abort();
 446         }
 447
 448         result = RSA_generate_key_ex(rsa_key, bits, e, cb);
 449
 450         BN_free(e);
 451         BN_GENCB_free(cb);
 452
 453         if(!result) {
 454                 fprintf(stderr, "Error during key generation!\n");
 455                 RSA_free(rsa_key);
 456                 return false;
 457         } else {
 458                 fprintf(stderr, "Done.\n");
 459         }
 460
 461         snprintf(filename, sizeof(filename), "%s/rsa_key.priv", confbase);
 462         f = ask_and_open(filename, "private RSA key");
 463
 464         if(!f) {
 465                 RSA_free(rsa_key);
 466                 return false;
 467         }
 468
 469 #ifdef HAVE_FCHMOD
 470         /* Make it unreadable for others. */
 471         fchmod(fileno(f), 0600);
 472 #endif
 473
 474         fputc('\n', f);
 475         PEM_write_RSAPrivateKey(f, rsa_key, NULL, NULL, 0, NULL, NULL);
 476         fclose(f);
 477
 478         char *name = get_name();
 479
 480         if(name) {
 481                 snprintf(filename, sizeof(filename), "%s/hosts/%s", confbase, name);
 482                 free(name);
 483         } else {
 484                 snprintf(filename, sizeof(filename), "%s/rsa_key.pub", confbase);
 485         }
 486
 487         f = ask_and_open(filename, "public RSA key");
 488
 489         if(!f) {
 490                 RSA_free(rsa_key);
 491                 return false;
 492         }
 493
 494         fputc('\n', f);
 495         PEM_write_RSAPublicKey(f, rsa_key);
 496         fclose(f);
 497
 498         RSA_free(rsa_key);
 499
 500         return true;
 501 }
 502
 503 /*
 504   Set all files and paths according to netname
 505 */
 506 static void make_names(void) {
 507 #ifdef HAVE_MINGW
 508         HKEY key;
 509         char installdir[1024] = "";
 510         DWORD len = sizeof(installdir);
 511 #endif
 512
 513         if(netname) {
 514                 xasprintf(&identname, "tinc.%s", netname);
 515         } else {
 516                 identname = xstrdup("tinc");
 517         }
 518
 519 #ifdef HAVE_MINGW
 520
 521         if(!RegOpenKeyEx(HKEY_LOCAL_MACHINE, "SOFTWARE\\tinc", 0, KEY_READ, &key)) {
 522                 if(!RegQueryValueEx(key, NULL, 0, 0, (LPBYTE)installdir, &len)) {
 523                         if(!confbase) {
 524                                 if(netname) {
 525                                         xasprintf(&confbase, "%s/%s", installdir, netname);
 526                                 } else {
 527                                         xasprintf(&confbase, "%s", installdir);
 528                                 }
 529                         }
 530
 531                         if(!logfilename) {
 532                                 xasprintf(&logfilename, "%s/tinc.log", confbase);
 533                         }
 534                 }
 535
 536                 RegCloseKey(key);
 537
 538                 if(*installdir) {
 539                         return;
 540                 }
 541         }
 542
 543 #endif
 544
 545         if(!pidfilename) {
 546                 xasprintf(&pidfilename, RUNSTATEDIR "/%s.pid", identname);
 547         }
 548
 549         if(!logfilename) {
 550                 xasprintf(&logfilename, LOCALSTATEDIR "/log/%s.log", identname);
 551         }
 552
 553         if(netname) {
 554                 if(!confbase) {
 555                         xasprintf(&confbase, CONFDIR "/tinc/%s", netname);
 556                 } else {
 557                         logger(LOG_INFO, "Both netname and configuration directory given, using the latter...");
 558                 }
 559         } else {
 560                 if(!confbase) {
 561                         xasprintf(&confbase, CONFDIR "/tinc");
 562                 }
 563         }
 564 }
 565
 566 static void free_names() {
 567         free(identname);
 568         free(netname);
 569         free(pidfilename);
 570         free(logfilename);
 571         free(confbase);
 572 }
 573
 574 static bool drop_privs() {
 575 #ifdef HAVE_MINGW
 576
 577         if(switchuser) {
 578                 logger(LOG_ERR, "%s not supported on this platform", "-U");
 579                 return false;
 580         }
 581
 582         if(do_chroot) {
 583                 logger(LOG_ERR, "%s not supported on this platform", "-R");
 584                 return false;
 585         }
 586
 587 #else
 588         uid_t uid = 0;
 589
 590         if(switchuser) {
 591                 struct passwd *pw = getpwnam(switchuser);
 592
 593                 if(!pw) {
 594                         logger(LOG_ERR, "unknown user `%s'", switchuser);
 595                         return false;
 596                 }
 597
 598                 uid = pw->pw_uid;
 599
 600                 if(initgroups(switchuser, pw->pw_gid) != 0 ||
 601                                 setgid(pw->pw_gid) != 0) {
 602                         logger(LOG_ERR, "System call `%s' failed: %s",
 603                                "initgroups", strerror(errno));
 604                         return false;
 605                 }
 606
 607 #ifndef ANDROID
 608 // Not supported in android NDK
 609                 endgrent();
 610                 endpwent();
 611 #endif
 612         }
 613
 614         if(do_chroot) {
 615                 tzset();        /* for proper timestamps in logs */
 616
 617                 if(chroot(confbase) != 0 || chdir("/") != 0) {
 618                         logger(LOG_ERR, "System call `%s' failed: %s",
 619                                "chroot", strerror(errno));
 620                         return false;
 621                 }
 622
 623                 free(confbase);
 624                 confbase = xstrdup("");
 625         }
 626
 627         if(switchuser)
 628                 if(setuid(uid) != 0) {
 629                         logger(LOG_ERR, "System call `%s' failed: %s",
 630                                "setuid", strerror(errno));
 631                         return false;
 632                 }
 633
 634 #endif
 635         return true;
 636 }
 637
 638 #ifdef HAVE_MINGW
 639 # define setpriority(level) !SetPriorityClass(GetCurrentProcess(), (level))
 640 #else
 641 # define NORMAL_PRIORITY_CLASS 0
 642 # define BELOW_NORMAL_PRIORITY_CLASS 10
 643 # define HIGH_PRIORITY_CLASS -10
 644 # define setpriority(level) (setpriority(PRIO_PROCESS, 0, (level)))
 645 #endif
 646
 647 int main(int argc, char **argv) {
 648         program_name = argv[0];
 649
 650         if(!parse_options(argc, argv)) {
 651                 return 1;
 652         }
 653
 654         if(show_version) {
 655                 printf("%s version %s\n", PACKAGE, VERSION);
 656                 printf("Copyright (C) 1998-2018 Ivo Timmermans, Guus Sliepen and others.\n"
 657                        "See the AUTHORS file for a complete list.\n\n"
 658                        "tinc comes with ABSOLUTELY NO WARRANTY.  This is free software,\n"
 659                        "and you are welcome to redistribute it under certain conditions;\n"
 660                        "see the file COPYING for details.\n");
 661
 662                 return 0;
 663         }
 664
 665         if(show_help) {
 666                 usage(false);
 667                 return 0;
 668         }
 669
 670         make_names();
 671
 672         if(kill_tincd) {
 673                 return !kill_other(kill_tincd);
 674         }
 675
 676         openlogger("tinc", use_logfile ? LOGMODE_FILE : LOGMODE_STDERR);
 677
 678         g_argv = argv;
 679
 680         if(getenv("LISTEN_PID") && atoi(getenv("LISTEN_PID")) == getpid()) {
 681                 do_detach = false;
 682         }
 683
 684 #ifdef HAVE_UNSETENV
 685         unsetenv("LISTEN_PID");
 686 #endif
 687
 688         init_configuration(&config_tree);
 689
 690 #ifndef OPENSSL_NO_ENGINE
 691         ENGINE_load_builtin_engines();
 692         ENGINE_register_all_complete();
 693 #endif
 694
 695         OpenSSL_add_all_algorithms();
 696
 697         if(generate_keys) {
 698                 read_server_config();
 699                 return !keygen(generate_keys);
 700         }
 701
 702         if(!read_server_config()) {
 703                 return 1;
 704         }
 705
 706 #ifdef HAVE_LZO
 707
 708         if(lzo_init() != LZO_E_OK) {
 709                 logger(LOG_ERR, "Error initializing LZO compressor!");
 710                 return 1;
 711         }
 712
 713 #endif
 714
 715 #ifdef HAVE_MINGW
 716
 717         if(WSAStartup(MAKEWORD(2, 2), &wsa_state)) {
 718                 logger(LOG_ERR, "System call `%s' failed: %s", "WSAStartup", winerror(GetLastError()));
 719                 return 1;
 720         }
 721
 722         if(!do_detach || !init_service()) {
 723                 return main2(argc, argv);
 724         } else {
 725                 return 1;
 726         }
 727 }
 728
 729 int main2(int argc, char **argv) {
 730         InitializeCriticalSection(&mutex);
 731         EnterCriticalSection(&mutex);
 732 #endif
 733         char *priority = NULL;
 734
 735         if(!detach()) {
 736                 return 1;
 737         }
 738
 739 #ifdef HAVE_MLOCKALL
 740
 741         /* Lock all pages into memory if requested.
 742          * This has to be done after daemon()/fork() so it works for child.
 743          * No need to do that in parent as it's very short-lived. */
 744         if(do_mlock && mlockall(MCL_CURRENT | MCL_FUTURE) != 0) {
 745                 logger(LOG_ERR, "System call `%s' failed: %s", "mlockall",
 746                        strerror(errno));
 747                 return 1;
 748         }
 749
 750 #endif
 751
 752         /* Setup sockets and open device. */
 753
 754         if(!setup_network()) {
 755                 goto end;
 756         }
 757
 758         /* Initiate all outgoing connections. */
 759
 760         try_outgoing_connections();
 761
 762         /* Change process priority */
 763
 764         if(get_config_string(lookup_config(config_tree, "ProcessPriority"), &priority)) {
 765                 if(!strcasecmp(priority, "Normal")) {
 766                         if(setpriority(NORMAL_PRIORITY_CLASS) != 0) {
 767                                 logger(LOG_ERR, "System call `%s' failed: %s",
 768                                        "setpriority", strerror(errno));
 769                                 goto end;
 770                         }
 771                 } else if(!strcasecmp(priority, "Low")) {
 772                         if(setpriority(BELOW_NORMAL_PRIORITY_CLASS) != 0) {
 773                                 logger(LOG_ERR, "System call `%s' failed: %s",
 774                                        "setpriority", strerror(errno));
 775                                 goto end;
 776                         }
 777                 } else if(!strcasecmp(priority, "High")) {
 778                         if(setpriority(HIGH_PRIORITY_CLASS) != 0) {
 779                                 logger(LOG_ERR, "System call `%s' failed: %s",
 780                                        "setpriority", strerror(errno));
 781                                 goto end;
 782                         }
 783                 } else {
 784                         logger(LOG_ERR, "Invalid priority `%s`!", priority);
 785                         goto end;
 786                 }
 787         }
 788
 789         /* drop privileges */
 790         if(!drop_privs()) {
 791                 goto end;
 792         }
 793
 794         /* Start main loop. It only exits when tinc is killed. */
 795
 796         status = main_loop();
 797
 798         /* Shutdown properly. */
 799
 800         ifdebug(CONNECTIONS)
 801         devops.dump_stats();
 802
 803         close_network_connections();
 804
 805 end:
 806         logger(LOG_NOTICE, "Terminating");
 807
 808 #ifndef HAVE_MINGW
 809         remove_pid(pidfilename);
 810 #endif
 811
 812         free(priority);
 813
 814         EVP_cleanup();
 815         ERR_free_strings();
 816 #ifndef OPENSSL_NO_ENGINE
 817         ENGINE_cleanup();
 818 #endif
 819
 820         exit_configuration(&config_tree);
 821         list_delete_list(cmdline_conf);
 822         free_names();
 823
 824         return status;
 825 }