src/process.c

   1 /*
   2     process.c -- process management functions
   3     Copyright (C) 1999-2005 Ivo Timmermans,
   4                   2000-2011 Guus Sliepen <guus@tinc-vpn.org>
   5
   6     This program is free software; you can redistribute it and/or modify
   7     it under the terms of the GNU General Public License as published by
   8     the Free Software Foundation; either version 2 of the License, or
   9     (at your option) any later version.
  10
  11     This program is distributed in the hope that it will be useful,
  12     but WITHOUT ANY WARRANTY; without even the implied warranty of
  13     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14     GNU General Public License for more details.
  15
  16     You should have received a copy of the GNU General Public License along
  17     with this program; if not, write to the Free Software Foundation, Inc.,
  18     51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  19 */
  20
  21 #include "system.h"
  22
  23 #include "conf.h"
  24 #include "connection.h"
  25 #include "device.h"
  26 #include "edge.h"
  27 #include "logger.h"
  28 #include "net.h"
  29 #include "node.h"
  30 #include "pidfile.h"
  31 #include "process.h"
  32 #include "subnet.h"
  33 #include "utils.h"
  34 #include "xalloc.h"
  35
  36 /* If zero, don't detach from the terminal. */
  37 bool do_detach = true;
  38 bool sighup = false;
  39 bool sigalrm = false;
  40
  41 extern char *identname;
  42 extern char *pidfilename;
  43 extern char **g_argv;
  44 extern bool use_logfile;
  45
  46 #ifndef HAVE_MINGW
  47 static sigset_t emptysigset;
  48 #endif
  49
  50 static int saved_debug_level = -1;
  51
  52 static void memory_full(int size) {
  53         logger(LOG_ERR, "Memory exhausted (couldn't allocate %d bytes), exitting.", size);
  54         exit(1);
  55 }
  56
  57 /* Some functions the less gifted operating systems might lack... */
  58
  59 #ifdef HAVE_MINGW
  60 extern char *identname;
  61 extern char *program_name;
  62 extern char **g_argv;
  63
  64 static SC_HANDLE manager = NULL;
  65 static SC_HANDLE service = NULL;
  66 static SERVICE_STATUS status = {0};
  67 static SERVICE_STATUS_HANDLE statushandle = 0;
  68
  69 bool install_service(void) {
  70         char command[4096] = "\"";
  71         char **argp;
  72         bool space;
  73         SERVICE_DESCRIPTION description = {"Virtual Private Network daemon"};
  74
  75         manager = OpenSCManager(NULL, NULL, SC_MANAGER_ALL_ACCESS);
  76         if(!manager) {
  77                 logger(LOG_ERR, "Could not open service manager: %s", winerror(GetLastError()));
  78                 return false;
  79         }
  80
  81         if(!strchr(program_name, '\\')) {
  82                 GetCurrentDirectory(sizeof command - 1, command + 1);
  83                 strncat(command, "\\", sizeof command - strlen(command));
  84         }
  85
  86         strncat(command, program_name, sizeof command - strlen(command));
  87
  88         strncat(command, "\"", sizeof command - strlen(command));
  89
  90         for(argp = g_argv + 1; *argp; argp++) {
  91                 space = strchr(*argp, ' ');
  92                 strncat(command, " ", sizeof command - strlen(command));
  93
  94                 if(space)
  95                         strncat(command, "\"", sizeof command - strlen(command));
  96
  97                 strncat(command, *argp, sizeof command - strlen(command));
  98
  99                 if(space)
 100                         strncat(command, "\"", sizeof command - strlen(command));
 101         }
 102
 103         service = CreateService(manager, identname, identname,
 104                         SERVICE_ALL_ACCESS, SERVICE_WIN32_OWN_PROCESS, SERVICE_AUTO_START, SERVICE_ERROR_NORMAL,
 105                         command, NULL, NULL, NULL, NULL, NULL);
 106
 107         if(!service) {
 108                 DWORD lasterror = GetLastError();
 109                 logger(LOG_ERR, "Could not create %s service: %s", identname, winerror(lasterror));
 110                 if(lasterror != ERROR_SERVICE_EXISTS)
 111                         return false;
 112         }
 113
 114         if(service) {
 115                 ChangeServiceConfig2(service, SERVICE_CONFIG_DESCRIPTION, &description);
 116                 logger(LOG_INFO, "%s service installed", identname);
 117         } else {
 118                 service = OpenService(manager, identname, SERVICE_ALL_ACCESS);
 119         }
 120
 121         if(!StartService(service, 0, NULL))
 122                 logger(LOG_WARNING, "Could not start %s service: %s", identname, winerror(GetLastError()));
 123         else
 124                 logger(LOG_INFO, "%s service started", identname);
 125
 126         return true;
 127 }
 128
 129 bool remove_service(void) {
 130         manager = OpenSCManager(NULL, NULL, SC_MANAGER_ALL_ACCESS);
 131         if(!manager) {
 132                 logger(LOG_ERR, "Could not open service manager: %s", winerror(GetLastError()));
 133                 return false;
 134         }
 135
 136         service = OpenService(manager, identname, SERVICE_ALL_ACCESS);
 137
 138         if(!service) {
 139                 logger(LOG_ERR, "Could not open %s service: %s", identname, winerror(GetLastError()));
 140                 return false;
 141         }
 142
 143         if(!ControlService(service, SERVICE_CONTROL_STOP, &status))
 144                 logger(LOG_ERR, "Could not stop %s service: %s", identname, winerror(GetLastError()));
 145         else
 146                 logger(LOG_INFO, "%s service stopped", identname);
 147
 148         if(!DeleteService(service)) {
 149                 logger(LOG_ERR, "Could not remove %s service: %s", identname, winerror(GetLastError()));
 150                 return false;
 151         }
 152
 153         logger(LOG_INFO, "%s service removed", identname);
 154
 155         return true;
 156 }
 157
 158 DWORD WINAPI controlhandler(DWORD request, DWORD type, LPVOID boe, LPVOID bah) {
 159         switch(request) {
 160                 case SERVICE_CONTROL_INTERROGATE:
 161                         SetServiceStatus(statushandle, &status);
 162                         return NO_ERROR;
 163                 case SERVICE_CONTROL_STOP:
 164                         logger(LOG_NOTICE, "Got %s request", "SERVICE_CONTROL_STOP");
 165                         break;
 166                 case SERVICE_CONTROL_SHUTDOWN:
 167                         logger(LOG_NOTICE, "Got %s request", "SERVICE_CONTROL_SHUTDOWN");
 168                         break;
 169                 default:
 170                         logger(LOG_WARNING, "Got unexpected request %d", request);
 171                         return ERROR_CALL_NOT_IMPLEMENTED;
 172         }
 173
 174         if(running) {
 175                 running = false;
 176                 status.dwWaitHint = 30000;
 177                 status.dwCurrentState = SERVICE_STOP_PENDING;
 178                 SetServiceStatus(statushandle, &status);
 179                 return NO_ERROR;
 180         } else {
 181                 status.dwWaitHint = 0;
 182                 status.dwCurrentState = SERVICE_STOPPED;
 183                 SetServiceStatus(statushandle, &status);
 184                 exit(1);
 185         }
 186
 187 }
 188
 189 VOID WINAPI run_service(DWORD argc, LPTSTR* argv) {
 190         int err = 1;
 191         extern int main2(int argc, char **argv);
 192
 193
 194         status.dwServiceType = SERVICE_WIN32;
 195         status.dwControlsAccepted = SERVICE_ACCEPT_STOP | SERVICE_ACCEPT_SHUTDOWN;
 196         status.dwWin32ExitCode = 0;
 197         status.dwServiceSpecificExitCode = 0;
 198         status.dwCheckPoint = 0;
 199
 200         statushandle = RegisterServiceCtrlHandlerEx(identname, controlhandler, NULL);
 201
 202         if (!statushandle) {
 203                 logger(LOG_ERR, "System call `%s' failed: %s", "RegisterServiceCtrlHandlerEx", winerror(GetLastError()));
 204                 err = 1;
 205         } else {
 206                 status.dwWaitHint = 30000;
 207                 status.dwCurrentState = SERVICE_START_PENDING;
 208                 SetServiceStatus(statushandle, &status);
 209
 210                 status.dwWaitHint = 0;
 211                 status.dwCurrentState = SERVICE_RUNNING;
 212                 SetServiceStatus(statushandle, &status);
 213
 214                 err = main2(argc, argv);
 215
 216                 status.dwWaitHint = 0;
 217                 status.dwCurrentState = SERVICE_STOPPED;
 218                 //status.dwWin32ExitCode = err;
 219                 SetServiceStatus(statushandle, &status);
 220         }
 221
 222         return;
 223 }
 224
 225 bool init_service(void) {
 226         SERVICE_TABLE_ENTRY services[] = {
 227                 {identname, run_service},
 228                 {NULL, NULL}
 229         };
 230
 231         if(!StartServiceCtrlDispatcher(services)) {
 232                 if(GetLastError() == ERROR_FAILED_SERVICE_CONTROLLER_CONNECT) {
 233                         return false;
 234                 }
 235                 else
 236                         logger(LOG_ERR, "System call `%s' failed: %s", "StartServiceCtrlDispatcher", winerror(GetLastError()));
 237         }
 238
 239         return true;
 240 }
 241 #endif
 242
 243 #ifndef HAVE_MINGW
 244 /*
 245   check for an existing tinc for this net, and write pid to pidfile
 246 */
 247 static bool write_pidfile(void) {
 248         pid_t pid;
 249
 250         pid = check_pid(pidfilename);
 251
 252         if(pid) {
 253                 if(netname)
 254                         fprintf(stderr, "A tincd is already running for net `%s' with pid %ld.\n",
 255                                         netname, (long)pid);
 256                 else
 257                         fprintf(stderr, "A tincd is already running with pid %ld.\n", (long)pid);
 258                 return false;
 259         }
 260
 261         /* if it's locked, write-protected, or whatever */
 262         if(!write_pid(pidfilename)) {
 263                 fprintf(stderr, "Could write pid file %s: %s\n", pidfilename, strerror(errno));
 264                 return false;
 265         }
 266
 267         return true;
 268 }
 269 #endif
 270
 271 /*
 272   kill older tincd for this net
 273 */
 274 bool kill_other(int signal) {
 275 #ifndef HAVE_MINGW
 276         pid_t pid;
 277
 278         pid = read_pid(pidfilename);
 279
 280         if(!pid) {
 281                 if(netname)
 282                         fprintf(stderr, "No other tincd is running for net `%s'.\n",
 283                                         netname);
 284                 else
 285                         fprintf(stderr, "No other tincd is running.\n");
 286                 return false;
 287         }
 288
 289         errno = 0;                                      /* No error, sometimes errno is only changed on error */
 290
 291         /* ESRCH is returned when no process with that pid is found */
 292         if(kill(pid, signal) && errno == ESRCH) {
 293                 if(netname)
 294                         fprintf(stderr, "The tincd for net `%s' is no longer running. ",
 295                                         netname);
 296                 else
 297                         fprintf(stderr, "The tincd is no longer running. ");
 298
 299                 fprintf(stderr, "Removing stale lock file.\n");
 300                 remove_pid(pidfilename);
 301         }
 302
 303         return true;
 304 #else
 305         return remove_service();
 306 #endif
 307 }
 308
 309 /*
 310   Detach from current terminal, write pidfile, kill parent
 311 */
 312 bool detach(void) {
 313         setup_signals();
 314
 315         /* First check if we can open a fresh new pidfile */
 316
 317 #ifndef HAVE_MINGW
 318         if(!write_pidfile())
 319                 return false;
 320
 321         /* If we succeeded in doing that, detach */
 322
 323         closelogger();
 324 #endif
 325
 326         if(do_detach) {
 327 #ifndef HAVE_MINGW
 328                 if(daemon(0, 0)) {
 329                         fprintf(stderr, "Couldn't detach from terminal: %s",
 330                                         strerror(errno));
 331                         return false;
 332                 }
 333
 334                 /* Now UPDATE the pid in the pidfile, because we changed it... */
 335
 336                 if(!write_pid(pidfilename)) {
 337                         fprintf(stderr, "Could not write pid file %s: %s\n", pidfilename, strerror(errno));
 338                         return false;
 339                 }
 340 #else
 341                 if(!statushandle)
 342                         exit(install_service());
 343 #endif
 344         }
 345
 346         openlogger(identname, use_logfile?LOGMODE_FILE:(do_detach?LOGMODE_SYSLOG:LOGMODE_STDERR));
 347
 348         logger(LOG_NOTICE, "tincd %s (%s %s) starting, debug level %d",
 349                            VERSION, __DATE__, __TIME__, debug_level);
 350
 351         xalloc_fail_func = memory_full;
 352
 353         return true;
 354 }
 355
 356 bool execute_script(const char *name, char **envp) {
 357 #ifdef HAVE_SYSTEM
 358         int status, len;
 359         char *scriptname;
 360         int i;
 361
 362 #ifndef HAVE_MINGW
 363         len = xasprintf(&scriptname, "\"%s/%s\"", confbase, name);
 364 #else
 365         len = xasprintf(&scriptname, "\"%s/%s.bat\"", confbase, name);
 366 #endif
 367         if(len < 0)
 368                 return false;
 369
 370         scriptname[len - 1] = '\0';
 371
 372 #ifndef HAVE_TUNEMU
 373         /* First check if there is a script */
 374
 375         if(access(scriptname + 1, F_OK)) {
 376                 free(scriptname);
 377                 return true;
 378         }
 379     else
 380     {
 381         // Ugly hard-code allowing execution of scripts on android without execution flag (such as on /sdcard)
 382         free(scriptname);
 383         len = xasprintf(&scriptname, "/system/bin/sh \"%s/%s\"", confbase, name);
 384         if(len < 0)
 385         {
 386             return false;
 387         }
 388     }
 389 #endif
 390
 391         ifdebug(STATUS) logger(LOG_INFO, "Executing script %s", name);
 392
 393 #ifdef HAVE_PUTENV
 394         /* Set environment */
 395
 396         for(i = 0; envp[i]; i++)
 397                 putenv(envp[i]);
 398 #endif
 399
 400         scriptname[len - 1] = '\"';
 401         status = system(scriptname);
 402
 403         free(scriptname);
 404
 405         /* Unset environment */
 406
 407         for(i = 0; envp[i]; i++) {
 408                 char *e = strchr(envp[i], '=');
 409                 if(e) {
 410                         char p[e - envp[i] + 1];
 411                         strncpy(p, envp[i], e - envp[i]);
 412                         p[e - envp[i]] = '\0';
 413                         putenv(p);
 414                 }
 415         }
 416
 417 #ifdef WEXITSTATUS
 418         if(status != -1) {
 419                 if(WIFEXITED(status)) { /* Child exited by itself */
 420                         if(WEXITSTATUS(status)) {
 421                                 logger(LOG_ERR, "Script %s exited with non-zero status %d",
 422                                            name, WEXITSTATUS(status));
 423                                 return false;
 424                         }
 425                 } else if(WIFSIGNALED(status)) {        /* Child was killed by a signal */
 426                         logger(LOG_ERR, "Script %s was killed by signal %d (%s)",
 427                                    name, WTERMSIG(status), strsignal(WTERMSIG(status)));
 428                         return false;
 429                 } else {                        /* Something strange happened */
 430                         logger(LOG_ERR, "Script %s terminated abnormally", name);
 431                         return false;
 432                 }
 433         } else {
 434                 logger(LOG_ERR, "System call `%s' failed: %s", "system", strerror(errno));
 435                 return false;
 436         }
 437 #endif
 438 #endif
 439         return true;
 440 }
 441
 442
 443 /*
 444   Signal handlers.
 445 */
 446
 447 #ifndef HAVE_MINGW
 448 static RETSIGTYPE sigterm_handler(int a) {
 449         logger(LOG_NOTICE, "Got %s signal", "TERM");
 450         if(running)
 451                 running = false;
 452         else
 453                 exit(1);
 454 }
 455
 456 static RETSIGTYPE sigquit_handler(int a) {
 457         logger(LOG_NOTICE, "Got %s signal", "QUIT");
 458         if(running)
 459                 running = false;
 460         else
 461                 exit(1);
 462 }
 463
 464 static RETSIGTYPE fatal_signal_square(int a) {
 465         logger(LOG_ERR, "Got another fatal signal %d (%s): not restarting.", a,
 466                    strsignal(a));
 467         exit(1);
 468 }
 469
 470 static RETSIGTYPE fatal_signal_handler(int a) {
 471         struct sigaction act;
 472         logger(LOG_ERR, "Got fatal signal %d (%s)", a, strsignal(a));
 473
 474         if(do_detach) {
 475                 logger(LOG_NOTICE, "Trying to re-execute in 5 seconds...");
 476
 477                 act.sa_handler = fatal_signal_square;
 478                 act.sa_mask = emptysigset;
 479                 act.sa_flags = 0;
 480                 sigaction(SIGSEGV, &act, NULL);
 481
 482                 close_network_connections();
 483                 sleep(5);
 484                 remove_pid(pidfilename);
 485                 execvp(g_argv[0], g_argv);
 486         } else {
 487                 logger(LOG_NOTICE, "Not restarting.");
 488                 exit(1);
 489         }
 490 }
 491
 492 static RETSIGTYPE sighup_handler(int a) {
 493         logger(LOG_NOTICE, "Got %s signal", "HUP");
 494         sighup = true;
 495 }
 496
 497 static RETSIGTYPE sigint_handler(int a) {
 498         logger(LOG_NOTICE, "Got %s signal", "INT");
 499
 500         if(saved_debug_level != -1) {
 501                 logger(LOG_NOTICE, "Reverting to old debug level (%d)",
 502                         saved_debug_level);
 503                 debug_level = saved_debug_level;
 504                 saved_debug_level = -1;
 505         } else {
 506                 logger(LOG_NOTICE,
 507                         "Temporarily setting debug level to 5.  Kill me with SIGINT again to go back to level %d.",
 508                         debug_level);
 509                 saved_debug_level = debug_level;
 510                 debug_level = 5;
 511         }
 512 }
 513
 514 static RETSIGTYPE sigalrm_handler(int a) {
 515         logger(LOG_NOTICE, "Got %s signal", "ALRM");
 516         sigalrm = true;
 517 }
 518
 519 static RETSIGTYPE sigusr1_handler(int a) {
 520         dump_connections();
 521 }
 522
 523 static RETSIGTYPE sigusr2_handler(int a) {
 524         devops.dump_stats();
 525         dump_nodes();
 526         dump_edges();
 527         dump_subnets();
 528 }
 529
 530 static RETSIGTYPE sigwinch_handler(int a) {
 531         do_purge = true;
 532 }
 533
 534 static RETSIGTYPE unexpected_signal_handler(int a) {
 535         logger(LOG_WARNING, "Got unexpected signal %d (%s)", a, strsignal(a));
 536 }
 537
 538 static RETSIGTYPE ignore_signal_handler(int a) {
 539         ifdebug(SCARY_THINGS) logger(LOG_DEBUG, "Ignored signal %d (%s)", a, strsignal(a));
 540 }
 541
 542 static struct {
 543         int signal;
 544         void (*handler)(int);
 545 } sighandlers[] = {
 546         {SIGHUP, sighup_handler},
 547         {SIGTERM, sigterm_handler},
 548         {SIGQUIT, sigquit_handler},
 549         {SIGSEGV, fatal_signal_handler},
 550         {SIGBUS, fatal_signal_handler},
 551         {SIGILL, fatal_signal_handler},
 552         {SIGPIPE, ignore_signal_handler},
 553         {SIGINT, sigint_handler},
 554         {SIGUSR1, sigusr1_handler},
 555         {SIGUSR2, sigusr2_handler},
 556         {SIGCHLD, ignore_signal_handler},
 557         {SIGALRM, sigalrm_handler},
 558         {SIGWINCH, sigwinch_handler},
 559         {SIGABRT, SIG_DFL},
 560         {0, NULL}
 561 };
 562 #endif
 563
 564 void setup_signals(void) {
 565 #ifndef HAVE_MINGW
 566         int i;
 567         struct sigaction act;
 568
 569         sigemptyset(&emptysigset);
 570         act.sa_handler = NULL;
 571         act.sa_mask = emptysigset;
 572         act.sa_flags = 0;
 573
 574         /* Set a default signal handler for every signal, errors will be
 575            ignored. */
 576         for(i = 1; i < NSIG; i++) {
 577                 if(!do_detach)
 578                         act.sa_handler = SIG_DFL;
 579                 else
 580                         act.sa_handler = unexpected_signal_handler;
 581                 sigaction(i, &act, NULL);
 582         }
 583
 584         /* If we didn't detach, allow coredumps */
 585         if(!do_detach)
 586                 sighandlers[3].handler = SIG_DFL;
 587
 588         /* Then, for each known signal that we want to catch, assign a
 589            handler to the signal, with error checking this time. */
 590         for(i = 0; sighandlers[i].signal; i++) {
 591                 act.sa_handler = sighandlers[i].handler;
 592                 if(sigaction(sighandlers[i].signal, &act, NULL) < 0)
 593                         fprintf(stderr, "Installing signal handler for signal %d (%s) failed: %s\n",
 594                                         sighandlers[i].signal, strsignal(sighandlers[i].signal),
 595                                         strerror(errno));
 596         }
 597 #endif
 598 }