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 #include <openssl/bn.h>
  44
  45 #ifdef HAVE_LZO
  46 #include LZO1X_H
  47 #endif
  48
  49 #ifndef HAVE_MINGW
  50 #include <pwd.h>
  51 #include <grp.h>
  52 #include <time.h>
  53 #endif
  54
  55 #ifdef HAVE_GETOPT_LONG
  56 #include <getopt.h>
  57 #else
  58 #include "getopt.h"
  59 #endif
  60
  61 #include "pidfile.h"
  62
  63 #include "conf.h"
  64 #include "device.h"
  65 #include "logger.h"
  66 #include "net.h"
  67 #include "netutl.h"
  68 #include "process.h"
  69 #include "protocol.h"
  70 #include "utils.h"
  71 #include "xalloc.h"
  72
  73 /* The name this program was run with. */
  74 char *program_name = NULL;
  75
  76 /* If nonzero, display usage information and exit. */
  77 bool show_help = false;
  78
  79 /* If nonzero, print the version on standard output and exit.  */
  80 bool show_version = false;
  81
  82 /* If nonzero, it will attempt to kill a running tincd and exit. */
  83 int kill_tincd = 0;
  84
  85 /* If nonzero, generate public/private keypair for this host/net. */
  86 int generate_keys = 0;
  87
  88 /* If nonzero, use null ciphers and skip all key exchanges. */
  89 bool bypass_security = false;
  90
  91 /* If nonzero, disable swapping for this process. */
  92 bool do_mlock = false;
  93
  94 /* If nonzero, chroot to netdir after startup. */
  95 static bool do_chroot = false;
  96
  97 /* If !NULL, do setuid to given user after startup */
  98 static const char *switchuser = NULL;
  99
 100 /* If nonzero, write log entries to a separate file. */
 101 bool use_logfile = false;
 102
 103 char *identname = NULL;                         /* program name for syslog */
 104 char *pidfilename = NULL;                       /* pid file location */
 105 char *logfilename = NULL;                       /* log file location */
 106 char **g_argv;                                  /* a copy of the cmdline arguments */
 107
 108 static int status = 1;
 109
 110 static struct option const long_options[] = {
 111         {"config", required_argument, NULL, 'c'},
 112         {"kill", optional_argument, NULL, 'k'},
 113         {"net", required_argument, NULL, 'n'},
 114         {"help", no_argument, NULL, 1},
 115         {"version", no_argument, NULL, 2},
 116         {"no-detach", no_argument, NULL, 'D'},
 117         {"generate-keys", optional_argument, NULL, 'K'},
 118         {"debug", optional_argument, NULL, 'd'},
 119         {"bypass-security", no_argument, NULL, 3},
 120         {"mlock", no_argument, NULL, 'L'},
 121         {"chroot", no_argument, NULL, 'R'},
 122         {"user", required_argument, NULL, 'U'},
 123         {"logfile", optional_argument, NULL, 4},
 124         {"pidfile", required_argument, NULL, 5},
 125         {"option", required_argument, NULL, 'o'},
 126         {NULL, 0, NULL, 0}
 127 };
 128
 129 #ifdef HAVE_MINGW
 130 static struct WSAData wsa_state;
 131 CRITICAL_SECTION mutex;
 132 int main2(int argc, char **argv);
 133 #endif
 134
 135 static void usage(bool status) {
 136         if(status)
 137                 fprintf(stderr, "Try `%s --help\' for more information.\n",
 138                         program_name);
 139         else {
 140                 printf("Usage: %s [option]...\n\n", program_name);
 141                 printf("  -c, --config=DIR               Read configuration options from DIR.\n"
 142                        "  -D, --no-detach                Don't fork and detach.\n"
 143                        "  -d, --debug[=LEVEL]            Increase debug level or set it to LEVEL.\n"
 144                        "  -k, --kill[=SIGNAL]            Attempt to kill a running tincd and exit.\n"
 145                        "  -n, --net=NETNAME              Connect to net NETNAME.\n"
 146                        "  -K, --generate-keys[=BITS]     Generate public/private RSA keypair.\n"
 147                        "  -L, --mlock                    Lock tinc into main memory.\n"
 148                        "      --logfile[=FILENAME]       Write log entries to a logfile.\n"
 149                        "      --pidfile=FILENAME         Write PID to FILENAME.\n"
 150                        "  -o, --option=[HOST.]KEY=VALUE  Set global/host configuration value.\n"
 151                        "  -R, --chroot                   chroot to NET dir at startup.\n"
 152                        "  -U, --user=USER                setuid to given USER at startup.\n"
 153                        "      --help                     Display this help and exit.\n"
 154                        "      --version                  Output version information and exit.\n\n");
 155                 printf("Report bugs to tinc@tinc-vpn.org.\n");
 156         }
 157 }
 158
 159 static bool parse_options(int argc, char **argv) {
 160         config_t *cfg;
 161         int r;
 162         int option_index = 0;
 163         int lineno = 0;
 164
 165         cmdline_conf = list_alloc((list_action_t)free_config);
 166
 167         while((r = getopt_long(argc, argv, "c:DLd::k::n:o:K::RU:", long_options, &option_index)) != EOF) {
 168                 switch(r) {
 169                 case 0:                         /* long option */
 170                         break;
 171
 172                 case 'c':                               /* config file */
 173                         if(confbase) {
 174                                 fprintf(stderr, "Only one configuration directory can be given.\n");
 175                                 usage(true);
 176                                 return false;
 177                         }
 178
 179                         confbase = xstrdup(optarg);
 180                         break;
 181
 182                 case 'D':                               /* no detach */
 183                         do_detach = false;
 184                         break;
 185
 186                 case 'L':                               /* no detach */
 187 #ifndef HAVE_MLOCKALL
 188                         logger(LOG_ERR, "%s not supported on this platform", "mlockall()");
 189                         return false;
 190 #else
 191                         do_mlock = true;
 192                         break;
 193 #endif
 194
 195                 case 'd':                               /* increase debug level */
 196                         if(!optarg && optind < argc && *argv[optind] != '-') {
 197                                 optarg = argv[optind++];
 198                         }
 199
 200                         if(optarg) {
 201                                 debug_level = atoi(optarg);
 202                         } else {
 203                                 debug_level++;
 204                         }
 205
 206                         break;
 207
 208                 case 'k':                               /* kill old tincds */
 209 #ifndef HAVE_MINGW
 210                         if(!optarg && optind < argc && *argv[optind] != '-') {
 211                                 optarg = argv[optind++];
 212                         }
 213
 214                         if(optarg) {
 215                                 if(!strcasecmp(optarg, "HUP")) {
 216                                         kill_tincd = SIGHUP;
 217                                 } else if(!strcasecmp(optarg, "TERM")) {
 218                                         kill_tincd = SIGTERM;
 219                                 } else if(!strcasecmp(optarg, "KILL")) {
 220                                         kill_tincd = SIGKILL;
 221                                 } else if(!strcasecmp(optarg, "USR1")) {
 222                                         kill_tincd = SIGUSR1;
 223                                 } else if(!strcasecmp(optarg, "USR2")) {
 224                                         kill_tincd = SIGUSR2;
 225                                 } else if(!strcasecmp(optarg, "WINCH")) {
 226                                         kill_tincd = SIGWINCH;
 227                                 } else if(!strcasecmp(optarg, "INT")) {
 228                                         kill_tincd = SIGINT;
 229                                 } else if(!strcasecmp(optarg, "ALRM")) {
 230                                         kill_tincd = SIGALRM;
 231                                 } else if(!strcasecmp(optarg, "ABRT")) {
 232                                         kill_tincd = SIGABRT;
 233                                 } else {
 234                                         kill_tincd = atoi(optarg);
 235
 236                                         if(!kill_tincd) {
 237                                                 fprintf(stderr, "Invalid argument `%s'; SIGNAL must be a number or one of HUP, TERM, KILL, USR1, USR2, WINCH, INT or ALRM.\n",
 238                                                         optarg);
 239                                                 usage(true);
 240                                                 return false;
 241                                         }
 242                                 }
 243                         } else {
 244                                 kill_tincd = SIGTERM;
 245                         }
 246
 247 #else
 248                         kill_tincd = 1;
 249 #endif
 250                         break;
 251
 252                 case 'n':                               /* net name given */
 253
 254                         /* netname "." is special: a "top-level name" */
 255                         if(netname) {
 256                                 fprintf(stderr, "Only one netname can be given.\n");
 257                                 usage(true);
 258                                 return false;
 259                         }
 260
 261                         if(optarg && strcmp(optarg, ".")) {
 262                                 netname = xstrdup(optarg);
 263                         }
 264
 265                         break;
 266
 267                 case 'o':                               /* option */
 268                         cfg = parse_config_line(optarg, NULL, ++lineno);
 269
 270                         if(!cfg) {
 271                                 return false;
 272                         }
 273
 274                         list_insert_tail(cmdline_conf, cfg);
 275                         break;
 276
 277                 case 'K':                               /* generate public/private keypair */
 278                         if(!optarg && optind < argc && *argv[optind] != '-') {
 279                                 optarg = argv[optind++];
 280                         }
 281
 282                         if(optarg) {
 283                                 generate_keys = atoi(optarg);
 284
 285                                 if(generate_keys < 512) {
 286                                         fprintf(stderr, "Invalid argument `%s'; BITS must be a number equal to or greater than 512.\n",
 287                                                 optarg);
 288                                         usage(true);
 289                                         return false;
 290                                 }
 291
 292                                 generate_keys &= ~7;    /* Round it to bytes */
 293                         } else {
 294                                 generate_keys = 2048;
 295                         }
 296
 297                         break;
 298
 299                 case 'R':                               /* chroot to NETNAME dir */
 300                         do_chroot = true;
 301                         break;
 302
 303                 case 'U':                               /* setuid to USER */
 304                         switchuser = optarg;
 305                         break;
 306
 307                 case 1:                                 /* show help */
 308                         show_help = true;
 309                         break;
 310
 311                 case 2:                                 /* show version */
 312                         show_version = true;
 313                         break;
 314
 315                 case 3:                                 /* bypass security */
 316                         bypass_security = true;
 317                         break;
 318
 319                 case 4:                                 /* write log entries to a file */
 320                         use_logfile = true;
 321
 322                         if(!optarg && optind < argc && *argv[optind] != '-') {
 323                                 optarg = argv[optind++];
 324                         }
 325
 326                         if(optarg) {
 327                                 if(logfilename) {
 328                                         fprintf(stderr, "Only one logfile can be given.\n");
 329                                         usage(true);
 330                                         return false;
 331                                 }
 332
 333                                 logfilename = xstrdup(optarg);
 334                         }
 335
 336                         break;
 337
 338                 case 5:                                 /* write PID to a file */
 339                         if(pidfilename) {
 340                                 fprintf(stderr, "Only one pidfile can be given.\n");
 341                                 usage(true);
 342                                 return false;
 343                         }
 344
 345                         pidfilename = xstrdup(optarg);
 346                         break;
 347
 348                 case '?':
 349                         usage(true);
 350                         return false;
 351
 352                 default:
 353                         break;
 354                 }
 355         }
 356
 357         if(optind < argc) {
 358                 fprintf(stderr, "%s: unrecognized argument '%s'\n", argv[0], argv[optind]);
 359                 usage(true);
 360                 return false;
 361         }
 362
 363         return true;
 364 }
 365
 366 /* This function prettyprints the key generation process */
 367
 368 static int indicator(int a, int b, BN_GENCB *cb) {
 369         (void)cb;
 370
 371         switch(a) {
 372         case 0:
 373                 fprintf(stderr, ".");
 374                 break;
 375
 376         case 1:
 377                 fprintf(stderr, "+");
 378                 break;
 379
 380         case 2:
 381                 fprintf(stderr, "-");
 382                 break;
 383
 384         case 3:
 385                 switch(b) {
 386                 case 0:
 387                         fprintf(stderr, " p\n");
 388                         break;
 389
 390                 case 1:
 391                         fprintf(stderr, " q\n");
 392                         break;
 393
 394                 default:
 395                         fprintf(stderr, "?");
 396                 }
 397
 398                 break;
 399
 400         default:
 401                 fprintf(stderr, "?");
 402         }
 403
 404         return 1;
 405 }
 406
 407 #ifndef HAVE_BN_GENCB_NEW
 408 BN_GENCB *BN_GENCB_new(void) {
 409         return xmalloc_and_zero(sizeof(BN_GENCB));
 410 }
 411
 412 void BN_GENCB_free(BN_GENCB *cb) {
 413         free(cb);
 414 }
 415 #endif
 416
 417 /*
 418   Generate a public/private RSA keypair, and ask for a file to store
 419   them in.
 420 */
 421 static bool keygen(int bits) {
 422         BIGNUM *e = NULL;
 423         RSA *rsa_key;
 424         FILE *f;
 425         char filename[PATH_MAX];
 426         BN_GENCB *cb;
 427         int result;
 428
 429         fprintf(stderr, "Generating %d bits keys:\n", bits);
 430
 431         cb = BN_GENCB_new();
 432
 433         if(!cb) {
 434                 abort();
 435         }
 436
 437         BN_GENCB_set(cb, indicator, NULL);
 438
 439         rsa_key = RSA_new();
 440
 441         if(BN_hex2bn(&e, "10001") == 0) {
 442                 abort();
 443         }
 444
 445         if(!rsa_key || !e) {
 446                 abort();
 447         }
 448
 449         result = RSA_generate_key_ex(rsa_key, bits, e, cb);
 450
 451         BN_free(e);
 452         BN_GENCB_free(cb);
 453
 454         if(!result) {
 455                 fprintf(stderr, "Error during key generation!\n");
 456                 RSA_free(rsa_key);
 457                 return false;
 458         } else {
 459                 fprintf(stderr, "Done.\n");
 460         }
 461
 462         snprintf(filename, sizeof(filename), "%s/rsa_key.priv", confbase);
 463         f = ask_and_open(filename, "private RSA key");
 464
 465         if(!f) {
 466                 RSA_free(rsa_key);
 467                 return false;
 468         }
 469
 470 #ifdef HAVE_FCHMOD
 471         /* Make it unreadable for others. */
 472         fchmod(fileno(f), 0600);
 473 #endif
 474
 475         fputc('\n', f);
 476         PEM_write_RSAPrivateKey(f, rsa_key, NULL, NULL, 0, NULL, NULL);
 477         fclose(f);
 478
 479         char *name = get_name();
 480
 481         if(name) {
 482                 snprintf(filename, sizeof(filename), "%s/hosts/%s", confbase, name);
 483                 free(name);
 484         } else {
 485                 snprintf(filename, sizeof(filename), "%s/rsa_key.pub", confbase);
 486         }
 487
 488         f = ask_and_open(filename, "public RSA key");
 489
 490         if(!f) {
 491                 RSA_free(rsa_key);
 492                 return false;
 493         }
 494
 495         fputc('\n', f);
 496         PEM_write_RSAPublicKey(f, rsa_key);
 497         fclose(f);
 498
 499         RSA_free(rsa_key);
 500
 501         return true;
 502 }
 503
 504 /*
 505   Set all files and paths according to netname
 506 */
 507 static void make_names(void) {
 508 #ifdef HAVE_MINGW
 509         HKEY key;
 510         char installdir[1024] = "";
 511         DWORD len = sizeof(installdir);
 512 #endif
 513
 514         if(netname) {
 515                 xasprintf(&identname, "tinc.%s", netname);
 516         } else {
 517                 identname = xstrdup("tinc");
 518         }
 519
 520 #ifdef HAVE_MINGW
 521
 522         if(!RegOpenKeyEx(HKEY_LOCAL_MACHINE, "SOFTWARE\\tinc", 0, KEY_READ, &key)) {
 523                 if(!RegQueryValueEx(key, NULL, 0, 0, (LPBYTE)installdir, &len)) {
 524                         if(!confbase) {
 525                                 if(netname) {
 526                                         xasprintf(&confbase, "%s/%s", installdir, netname);
 527                                 } else {
 528                                         xasprintf(&confbase, "%s", installdir);
 529                                 }
 530                         }
 531
 532                         if(!logfilename) {
 533                                 xasprintf(&logfilename, "%s/tinc.log", confbase);
 534                         }
 535                 }
 536
 537                 RegCloseKey(key);
 538
 539                 if(*installdir) {
 540                         return;
 541                 }
 542         }
 543
 544 #endif
 545
 546         if(!pidfilename) {
 547                 xasprintf(&pidfilename, RUNSTATEDIR "/%s.pid", identname);
 548         }
 549
 550         if(!logfilename) {
 551                 xasprintf(&logfilename, LOCALSTATEDIR "/log/%s.log", identname);
 552         }
 553
 554         if(netname) {
 555                 if(!confbase) {
 556                         xasprintf(&confbase, CONFDIR "/tinc/%s", netname);
 557                 } else {
 558                         logger(LOG_INFO, "Both netname and configuration directory given, using the latter...");
 559                 }
 560         } else {
 561                 if(!confbase) {
 562                         xasprintf(&confbase, CONFDIR "/tinc");
 563                 }
 564         }
 565 }
 566
 567 static void free_names() {
 568         free(identname);
 569         free(netname);
 570         free(pidfilename);
 571         free(logfilename);
 572         free(confbase);
 573 }
 574
 575 static bool drop_privs() {
 576 #ifdef HAVE_MINGW
 577
 578         if(switchuser) {
 579                 logger(LOG_ERR, "%s not supported on this platform", "-U");
 580                 return false;
 581         }
 582
 583         if(do_chroot) {
 584                 logger(LOG_ERR, "%s not supported on this platform", "-R");
 585                 return false;
 586         }
 587
 588 #else
 589         uid_t uid = 0;
 590
 591         if(switchuser) {
 592                 struct passwd *pw = getpwnam(switchuser);
 593
 594                 if(!pw) {
 595                         logger(LOG_ERR, "unknown user `%s'", switchuser);
 596                         return false;
 597                 }
 598
 599                 uid = pw->pw_uid;
 600
 601                 if(initgroups(switchuser, pw->pw_gid) != 0 ||
 602                                 setgid(pw->pw_gid) != 0) {
 603                         logger(LOG_ERR, "System call `%s' failed: %s",
 604                                "initgroups", strerror(errno));
 605                         return false;
 606                 }
 607
 608 #ifndef ANDROID
 609 // Not supported in android NDK
 610                 endgrent();
 611                 endpwent();
 612 #endif
 613         }
 614
 615         if(do_chroot) {
 616                 tzset();        /* for proper timestamps in logs */
 617
 618                 if(chroot(confbase) != 0 || chdir("/") != 0) {
 619                         logger(LOG_ERR, "System call `%s' failed: %s",
 620                                "chroot", strerror(errno));
 621                         return false;
 622                 }
 623
 624                 free(confbase);
 625                 confbase = xstrdup("");
 626         }
 627
 628         if(switchuser)
 629                 if(setuid(uid) != 0) {
 630                         logger(LOG_ERR, "System call `%s' failed: %s",
 631                                "setuid", strerror(errno));
 632                         return false;
 633                 }
 634
 635 #endif
 636         return true;
 637 }
 638
 639 #ifdef HAVE_MINGW
 640 # define setpriority(level) !SetPriorityClass(GetCurrentProcess(), (level))
 641 #else
 642 # define NORMAL_PRIORITY_CLASS 0
 643 # define BELOW_NORMAL_PRIORITY_CLASS 10
 644 # define HIGH_PRIORITY_CLASS -10
 645 # define setpriority(level) (setpriority(PRIO_PROCESS, 0, (level)))
 646 #endif
 647
 648 int main(int argc, char **argv) {
 649         program_name = argv[0];
 650
 651         if(!parse_options(argc, argv)) {
 652                 return 1;
 653         }
 654
 655         if(show_version) {
 656                 printf("%s version %s\n", PACKAGE, VERSION);
 657                 printf("Copyright (C) 1998-2018 Ivo Timmermans, Guus Sliepen and others.\n"
 658                        "See the AUTHORS file for a complete list.\n\n"
 659                        "tinc comes with ABSOLUTELY NO WARRANTY.  This is free software,\n"
 660                        "and you are welcome to redistribute it under certain conditions;\n"
 661                        "see the file COPYING for details.\n");
 662
 663                 return 0;
 664         }
 665
 666         if(show_help) {
 667                 usage(false);
 668                 return 0;
 669         }
 670
 671         make_names();
 672
 673         if(kill_tincd) {
 674                 return !kill_other(kill_tincd);
 675         }
 676
 677         openlogger("tinc", use_logfile ? LOGMODE_FILE : LOGMODE_STDERR);
 678
 679         g_argv = argv;
 680
 681         if(getenv("LISTEN_PID") && atoi(getenv("LISTEN_PID")) == getpid()) {
 682                 do_detach = false;
 683         }
 684
 685 #ifdef HAVE_UNSETENV
 686         unsetenv("LISTEN_PID");
 687 #endif
 688
 689         init_configuration(&config_tree);
 690
 691 #ifndef OPENSSL_NO_ENGINE
 692         ENGINE_load_builtin_engines();
 693         ENGINE_register_all_complete();
 694 #endif
 695
 696 #if OPENSSL_VERSION_NUMBER < 0x10100000L
 697         OpenSSL_add_all_algorithms();
 698 #endif
 699
 700         if(generate_keys) {
 701                 read_server_config();
 702                 return !keygen(generate_keys);
 703         }
 704
 705         if(!read_server_config()) {
 706                 return 1;
 707         }
 708
 709 #ifdef HAVE_LZO
 710
 711         if(lzo_init() != LZO_E_OK) {
 712                 logger(LOG_ERR, "Error initializing LZO compressor!");
 713                 return 1;
 714         }
 715
 716 #endif
 717
 718 #ifdef HAVE_MINGW
 719
 720         if(WSAStartup(MAKEWORD(2, 2), &wsa_state)) {
 721                 logger(LOG_ERR, "System call `%s' failed: %s", "WSAStartup", winerror(GetLastError()));
 722                 return 1;
 723         }
 724
 725         if(!do_detach || !init_service()) {
 726                 return main2(argc, argv);
 727         } else {
 728                 return 1;
 729         }
 730 }
 731
 732 int main2(int argc, char **argv) {
 733         InitializeCriticalSection(&mutex);
 734         EnterCriticalSection(&mutex);
 735 #endif
 736         char *priority = NULL;
 737
 738         if(!detach()) {
 739                 return 1;
 740         }
 741
 742 #ifdef HAVE_MLOCKALL
 743
 744         /* Lock all pages into memory if requested.
 745          * This has to be done after daemon()/fork() so it works for child.
 746          * No need to do that in parent as it's very short-lived. */
 747         if(do_mlock && mlockall(MCL_CURRENT | MCL_FUTURE) != 0) {
 748                 logger(LOG_ERR, "System call `%s' failed: %s", "mlockall",
 749                        strerror(errno));
 750                 return 1;
 751         }
 752
 753 #endif
 754
 755         /* Setup sockets and open device. */
 756
 757         if(!setup_network()) {
 758                 goto end;
 759         }
 760
 761         /* Initiate all outgoing connections. */
 762
 763         try_outgoing_connections();
 764
 765         /* Change process priority */
 766
 767         if(get_config_string(lookup_config(config_tree, "ProcessPriority"), &priority)) {
 768                 if(!strcasecmp(priority, "Normal")) {
 769                         if(setpriority(NORMAL_PRIORITY_CLASS) != 0) {
 770                                 logger(LOG_ERR, "System call `%s' failed: %s",
 771                                        "setpriority", strerror(errno));
 772                                 goto end;
 773                         }
 774                 } else if(!strcasecmp(priority, "Low")) {
 775                         if(setpriority(BELOW_NORMAL_PRIORITY_CLASS) != 0) {
 776                                 logger(LOG_ERR, "System call `%s' failed: %s",
 777                                        "setpriority", strerror(errno));
 778                                 goto end;
 779                         }
 780                 } else if(!strcasecmp(priority, "High")) {
 781                         if(setpriority(HIGH_PRIORITY_CLASS) != 0) {
 782                                 logger(LOG_ERR, "System call `%s' failed: %s",
 783                                        "setpriority", strerror(errno));
 784                                 goto end;
 785                         }
 786                 } else {
 787                         logger(LOG_ERR, "Invalid priority `%s`!", priority);
 788                         goto end;
 789                 }
 790         }
 791
 792         /* drop privileges */
 793         if(!drop_privs()) {
 794                 goto end;
 795         }
 796
 797         /* Start main loop. It only exits when tinc is killed. */
 798
 799         status = main_loop();
 800
 801         /* Shutdown properly. */
 802
 803         ifdebug(CONNECTIONS)
 804         devops.dump_stats();
 805
 806         close_network_connections();
 807
 808 end:
 809         logger(LOG_NOTICE, "Terminating");
 810
 811 #ifndef HAVE_MINGW
 812         remove_pid(pidfilename);
 813 #endif
 814
 815         free(priority);
 816
 817 #if OPENSSL_VERSION_NUMBER < 0x10100000L
 818         EVP_cleanup();
 819         ERR_free_strings();
 820 #ifndef OPENSSL_NO_ENGINE
 821         ENGINE_cleanup();
 822 #endif
 823 #endif
 824
 825         exit_configuration(&config_tree);
 826         list_delete_list(cmdline_conf);
 827         free_names();
 828
 829         return status;
 830 }