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 #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 *pubname, *privname;
 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(!rsa_key) {
 415                 fprintf(stderr, "Error during key generation!\n");
 416                 return false;
 417         } else
 418                 fprintf(stderr, "Done.\n");
 419
 420         xasprintf(&privname, "%s/rsa_key.priv", confbase);
 421         f = ask_and_open(privname, "private RSA key");
 422         free(privname);
 423
 424         if(!f)
 425                 return false;
 426
 427 #ifdef HAVE_FCHMOD
 428         /* Make it unreadable for others. */
 429         fchmod(fileno(f), 0600);
 430 #endif
 431
 432         fputc('\n', f);
 433         PEM_write_RSAPrivateKey(f, rsa_key, NULL, NULL, 0, NULL, NULL);
 434         fclose(f);
 435
 436         char *name = get_name();
 437
 438         if(name) {
 439                 xasprintf(&pubname, "%s/hosts/%s", confbase, name);
 440                 free(name);
 441         } else {
 442                 xasprintf(&pubname, "%s/rsa_key.pub", confbase);
 443         }
 444
 445         f = ask_and_open(pubname, "public RSA key");
 446         free(pubname);
 447
 448         if(!f)
 449                 return false;
 450
 451         fputc('\n', f);
 452         PEM_write_RSAPublicKey(f, rsa_key);
 453         fclose(f);
 454
 455         return true;
 456 }
 457
 458 /*
 459   Set all files and paths according to netname
 460 */
 461 static void make_names(void) {
 462 #ifdef HAVE_MINGW
 463         HKEY key;
 464         char installdir[1024] = "";
 465         DWORD len = sizeof(installdir);
 466 #endif
 467
 468         if(netname)
 469                 xasprintf(&identname, "tinc.%s", netname);
 470         else
 471                 identname = xstrdup("tinc");
 472
 473 #ifdef HAVE_MINGW
 474         if(!RegOpenKeyEx(HKEY_LOCAL_MACHINE, "SOFTWARE\\tinc", 0, KEY_READ, &key)) {
 475                 if(!RegQueryValueEx(key, NULL, 0, 0, (LPBYTE)installdir, &len)) {
 476                         if(!confbase) {
 477                                 if(netname)
 478                                         xasprintf(&confbase, "%s/%s", installdir, netname);
 479                                 else
 480                                         xasprintf(&confbase, "%s", installdir);
 481                         }
 482                         if(!logfilename)
 483                                 xasprintf(&logfilename, "%s/tinc.log", confbase);
 484                 }
 485                 RegCloseKey(key);
 486                 if(*installdir)
 487                         return;
 488         }
 489 #endif
 490
 491         if(!pidfilename)
 492                 xasprintf(&pidfilename, LOCALSTATEDIR "/run/%s.pid", identname);
 493
 494         if(!logfilename)
 495                 xasprintf(&logfilename, LOCALSTATEDIR "/log/%s.log", identname);
 496
 497         if(netname) {
 498                 if(!confbase)
 499                         xasprintf(&confbase, CONFDIR "/tinc/%s", netname);
 500                 else
 501                         logger(LOG_INFO, "Both netname and configuration directory given, using the latter...");
 502         } else {
 503                 if(!confbase)
 504                         xasprintf(&confbase, CONFDIR "/tinc");
 505         }
 506 }
 507
 508 static void free_names() {
 509         if (identname) free(identname);
 510         if (netname) free(netname);
 511         if (pidfilename) free(pidfilename);
 512         if (logfilename) free(logfilename);
 513         if (confbase) free(confbase);
 514 }
 515
 516 static bool drop_privs() {
 517 #ifdef HAVE_MINGW
 518         if (switchuser) {
 519                 logger(LOG_ERR, "%s not supported on this platform", "-U");
 520                 return false;
 521         }
 522         if (do_chroot) {
 523                 logger(LOG_ERR, "%s not supported on this platform", "-R");
 524                 return false;
 525         }
 526 #else
 527         uid_t uid = 0;
 528         if (switchuser) {
 529                 struct passwd *pw = getpwnam(switchuser);
 530                 if (!pw) {
 531                         logger(LOG_ERR, "unknown user `%s'", switchuser);
 532                         return false;
 533                 }
 534                 uid = pw->pw_uid;
 535                 if (initgroups(switchuser, pw->pw_gid) != 0 ||
 536                     setgid(pw->pw_gid) != 0) {
 537                         logger(LOG_ERR, "System call `%s' failed: %s",
 538                                "initgroups", strerror(errno));
 539                         return false;
 540                 }
 541 #ifndef __ANDROID__
 542 // Not supported in android NDK
 543                 endgrent();
 544                 endpwent();
 545 #endif
 546         }
 547         if (do_chroot) {
 548                 tzset();        /* for proper timestamps in logs */
 549                 if (chroot(confbase) != 0 || chdir("/") != 0) {
 550                         logger(LOG_ERR, "System call `%s' failed: %s",
 551                                "chroot", strerror(errno));
 552                         return false;
 553                 }
 554                 free(confbase);
 555                 confbase = xstrdup("");
 556         }
 557         if (switchuser)
 558                 if (setuid(uid) != 0) {
 559                         logger(LOG_ERR, "System call `%s' failed: %s",
 560                                "setuid", strerror(errno));
 561                         return false;
 562                 }
 563 #endif
 564         return true;
 565 }
 566
 567 #ifdef HAVE_MINGW
 568 # define setpriority(level) !SetPriorityClass(GetCurrentProcess(), (level))
 569 #else
 570 # define NORMAL_PRIORITY_CLASS 0
 571 # define BELOW_NORMAL_PRIORITY_CLASS 10
 572 # define HIGH_PRIORITY_CLASS -10
 573 # define setpriority(level) (setpriority(PRIO_PROCESS, 0, (level)))
 574 #endif
 575
 576 int main(int argc, char **argv) {
 577         program_name = argv[0];
 578
 579         if(!parse_options(argc, argv))
 580                 return 1;
 581
 582         make_names();
 583
 584         if(show_version) {
 585                 printf("%s version %s\n", PACKAGE, VERSION);
 586                 printf("Copyright (C) 1998-2016 Ivo Timmermans, Guus Sliepen and others.\n"
 587                                 "See the AUTHORS file for a complete list.\n\n"
 588                                 "tinc comes with ABSOLUTELY NO WARRANTY.  This is free software,\n"
 589                                 "and you are welcome to redistribute it under certain conditions;\n"
 590                                 "see the file COPYING for details.\n");
 591
 592                 return 0;
 593         }
 594
 595         if(show_help) {
 596                 usage(false);
 597                 return 0;
 598         }
 599
 600         if(kill_tincd)
 601                 return !kill_other(kill_tincd);
 602
 603         openlogger("tinc", use_logfile?LOGMODE_FILE:LOGMODE_STDERR);
 604
 605         g_argv = argv;
 606
 607         if(getenv("LISTEN_PID") && atoi(getenv("LISTEN_PID")) == getpid())
 608                 do_detach = false;
 609 #ifdef HAVE_UNSETENV
 610         unsetenv("LISTEN_PID");
 611 #endif
 612
 613         init_configuration(&config_tree);
 614
 615         /* Slllluuuuuuurrrrp! */
 616
 617         RAND_load_file("/dev/urandom", 1024);
 618
 619         ENGINE_load_builtin_engines();
 620         ENGINE_register_all_complete();
 621
 622         OpenSSL_add_all_algorithms();
 623
 624         if(generate_keys) {
 625                 read_server_config();
 626                 return !keygen(generate_keys);
 627         }
 628
 629         if(!read_server_config())
 630                 return 1;
 631
 632 #ifdef HAVE_LZO
 633         if(lzo_init() != LZO_E_OK) {
 634                 logger(LOG_ERR, "Error initializing LZO compressor!");
 635                 return 1;
 636         }
 637 #endif
 638
 639 #ifdef HAVE_MINGW
 640         if(WSAStartup(MAKEWORD(2, 2), &wsa_state)) {
 641                 logger(LOG_ERR, "System call `%s' failed: %s", "WSAStartup", winerror(GetLastError()));
 642                 return 1;
 643         }
 644
 645         if(!do_detach || !init_service())
 646                 return main2(argc, argv);
 647         else
 648                 return 1;
 649 }
 650
 651 int main2(int argc, char **argv) {
 652         InitializeCriticalSection(&mutex);
 653         EnterCriticalSection(&mutex);
 654 #endif
 655         char *priority = NULL;
 656
 657         if(!detach())
 658                 return 1;
 659
 660 #ifdef HAVE_MLOCKALL
 661         /* Lock all pages into memory if requested.
 662          * This has to be done after daemon()/fork() so it works for child.
 663          * No need to do that in parent as it's very short-lived. */
 664         if(do_mlock && mlockall(MCL_CURRENT | MCL_FUTURE) != 0) {
 665                 logger(LOG_ERR, "System call `%s' failed: %s", "mlockall",
 666                    strerror(errno));
 667                 return 1;
 668         }
 669 #endif
 670
 671         /* Setup sockets and open device. */
 672
 673         if(!setup_network())
 674                 goto end;
 675
 676         /* Initiate all outgoing connections. */
 677
 678         try_outgoing_connections();
 679
 680         /* Change process priority */
 681
 682         if(get_config_string(lookup_config(config_tree, "ProcessPriority"), &priority)) {
 683                 if(!strcasecmp(priority, "Normal")) {
 684                         if (setpriority(NORMAL_PRIORITY_CLASS) != 0) {
 685                                 logger(LOG_ERR, "System call `%s' failed: %s",
 686                                        "setpriority", strerror(errno));
 687                                 goto end;
 688                         }
 689                 } else if(!strcasecmp(priority, "Low")) {
 690                         if (setpriority(BELOW_NORMAL_PRIORITY_CLASS) != 0) {
 691                                        logger(LOG_ERR, "System call `%s' failed: %s",
 692                                        "setpriority", strerror(errno));
 693                                 goto end;
 694                         }
 695                 } else if(!strcasecmp(priority, "High")) {
 696                         if (setpriority(HIGH_PRIORITY_CLASS) != 0) {
 697                                 logger(LOG_ERR, "System call `%s' failed: %s",
 698                                        "setpriority", strerror(errno));
 699                                 goto end;
 700                         }
 701                 } else {
 702                         logger(LOG_ERR, "Invalid priority `%s`!", priority);
 703                         goto end;
 704                 }
 705         }
 706
 707         /* drop privileges */
 708         if (!drop_privs())
 709                 goto end;
 710
 711         /* Start main loop. It only exits when tinc is killed. */
 712
 713         status = main_loop();
 714
 715         /* Shutdown properly. */
 716
 717         ifdebug(CONNECTIONS)
 718                 devops.dump_stats();
 719
 720         close_network_connections();
 721
 722 end:
 723         logger(LOG_NOTICE, "Terminating");
 724
 725 #ifndef HAVE_MINGW
 726         remove_pid(pidfilename);
 727 #endif
 728
 729         free(priority);
 730
 731         EVP_cleanup();
 732         ENGINE_cleanup();
 733         CRYPTO_cleanup_all_ex_data();
 734 #ifdef HAVE_ERR_REMOVE_STATE
 735         // OpenSSL claims this function was deprecated in 1.0.0,
 736         // but valgrind's leak detector shows you still need to call it to make sure OpenSSL cleans up properly.
 737         ERR_remove_state(0);
 738 #endif
 739         ERR_free_strings();
 740
 741         exit_configuration(&config_tree);
 742         list_free(cmdline_conf);
 743         free_names();
 744
 745         return status;
 746 }