src/process.c

   1 /*
   2     process.c -- process management functions
   3     Copyright (C) 1999-2005 Ivo Timmermans,
   4                   2000-2006 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
  17     along with this program; if not, write to the Free Software
  18     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19
  20     $Id$
  21 */
  22
  23 #include "system.h"
  24
  25 #include "conf.h"
  26 #include "connection.h"
  27 #include "device.h"
  28 #include "edge.h"
  29 #include "logger.h"
  30 #include "node.h"
  31 #include "pidfile.h"
  32 #include "process.h"
  33 #include "subnet.h"
  34 #include "utils.h"
  35 #include "xalloc.h"
  36
  37 /* If zero, don't detach from the terminal. */
  38 bool do_detach = true;
  39 bool sighup = false;
  40 bool sigalrm = false;
  41
  42 extern char *identname;
  43 extern char *pidfilename;
  44 extern char **g_argv;
  45 extern bool use_logfile;
  46 extern volatile bool running;
  47
  48 sigset_t emptysigset;
  49
  50 static int saved_debug_level = -1;
  51
  52 static void memory_full(int size)
  53 {
  54         logger(LOG_ERR, _("Memory exhausted (couldn't allocate %d bytes), exitting."), size);
  55         cp_trace();
  56         exit(1);
  57 }
  58
  59 /* Some functions the less gifted operating systems might lack... */
  60
  61 #ifdef HAVE_MINGW
  62 extern char *identname;
  63 extern char *program_name;
  64 extern char **g_argv;
  65
  66 static SC_HANDLE manager = NULL;
  67 static SC_HANDLE service = NULL;
  68 static SERVICE_STATUS status = {0};
  69 static SERVICE_STATUS_HANDLE statushandle = 0;
  70
  71 bool install_service(void) {
  72         char command[4096] = "\"";
  73         char **argp;
  74         bool space;
  75         SERVICE_DESCRIPTION description = {"Virtual Private Network daemon"};
  76
  77         manager = OpenSCManager(NULL, NULL, SC_MANAGER_ALL_ACCESS);
  78         if(!manager) {
  79                 logger(LOG_ERR, _("Could not open service manager: %s"), winerror(GetLastError()));
  80                 return false;
  81         }
  82
  83         if(!strchr(program_name, '\\')) {
  84                 GetCurrentDirectory(sizeof command - 1, command + 1);
  85                 strncat(command, "\\", sizeof command - strlen(command));
  86         }
  87
  88         strncat(command, program_name, sizeof command - strlen(command));
  89
  90         strncat(command, "\"", sizeof command - strlen(command));
  91
  92         for(argp = g_argv + 1; *argp; argp++) {
  93                 space = strchr(*argp, ' ');
  94                 strncat(command, " ", sizeof command - strlen(command));
  95
  96                 if(space)
  97                         strncat(command, "\"", sizeof command - strlen(command));
  98
  99                 strncat(command, *argp, sizeof command - strlen(command));
 100
 101                 if(space)
 102                         strncat(command, "\"", sizeof command - strlen(command));
 103         }
 104
 105         service = CreateService(manager, identname, identname,
 106                         SERVICE_ALL_ACCESS, SERVICE_WIN32_OWN_PROCESS, SERVICE_AUTO_START, SERVICE_ERROR_NORMAL,
 107                         command, NULL, NULL, NULL, NULL, NULL);
 108
 109         if(!service) {
 110                 logger(LOG_ERR, _("Could not create %s service: %s"), identname, winerror(GetLastError()));
 111                 return false;
 112         }
 113
 114         ChangeServiceConfig2(service, SERVICE_CONFIG_DESCRIPTION, &description);
 115
 116         logger(LOG_INFO, _("%s service installed"), identname);
 117
 118         if(!StartService(service, 0, NULL))
 119                 logger(LOG_WARNING, _("Could not start %s service: %s"), identname, winerror(GetLastError()));
 120         else
 121                 logger(LOG_INFO, _("%s service started"), identname);
 122
 123         return true;
 124 }
 125
 126 bool remove_service(void) {
 127         manager = OpenSCManager(NULL, NULL, SC_MANAGER_ALL_ACCESS);
 128         if(!manager) {
 129                 logger(LOG_ERR, _("Could not open service manager: %s"), winerror(GetLastError()));
 130                 return false;
 131         }
 132
 133         service = OpenService(manager, identname, SERVICE_ALL_ACCESS);
 134
 135         if(!service) {
 136                 logger(LOG_ERR, _("Could not open %s service: %s"), identname, winerror(GetLastError()));
 137                 return false;
 138         }
 139
 140         if(!ControlService(service, SERVICE_CONTROL_STOP, &status))
 141                 logger(LOG_ERR, _("Could not stop %s service: %s"), identname, winerror(GetLastError()));
 142         else
 143                 logger(LOG_INFO, _("%s service stopped"), identname);
 144
 145         if(!DeleteService(service)) {
 146                 logger(LOG_ERR, _("Could not remove %s service: %s"), identname, winerror(GetLastError()));
 147                 return false;
 148         }
 149
 150         logger(LOG_INFO, _("%s service removed"), identname);
 151
 152         return true;
 153 }
 154
 155 DWORD WINAPI controlhandler(DWORD request, DWORD type, LPVOID boe, LPVOID bah) {
 156         switch(request) {
 157                 case SERVICE_CONTROL_STOP:
 158                         logger(LOG_NOTICE, _("Got %s request"), "SERVICE_CONTROL_STOP");
 159                         break;
 160                 case SERVICE_CONTROL_SHUTDOWN:
 161                         logger(LOG_NOTICE, _("Got %s request"), "SERVICE_CONTROL_SHUTDOWN");
 162                         break;
 163                 default:
 164                         logger(LOG_WARNING, _("Got unexpected request %d"), request);
 165                         return ERROR_CALL_NOT_IMPLEMENTED;
 166         }
 167
 168         if(running) {
 169                 running = false;
 170                 status.dwWaitHint = 30000;
 171                 status.dwCurrentState = SERVICE_STOP_PENDING;
 172                 SetServiceStatus(statushandle, &status);
 173                 return NO_ERROR;
 174         } else {
 175                 status.dwWaitHint = 0;
 176                 status.dwCurrentState = SERVICE_STOPPED;
 177                 SetServiceStatus(statushandle, &status);
 178                 exit(1);
 179         }
 180
 181 }
 182
 183 VOID WINAPI run_service(DWORD argc, LPTSTR* argv)
 184 {
 185         int err = 1;
 186         extern int main2(int argc, char **argv);
 187
 188
 189         status.dwServiceType = SERVICE_WIN32;
 190         status.dwControlsAccepted = SERVICE_ACCEPT_STOP | SERVICE_ACCEPT_SHUTDOWN;
 191         status.dwWin32ExitCode = 0;
 192         status.dwServiceSpecificExitCode = 0;
 193         status.dwCheckPoint = 0;
 194
 195         statushandle = RegisterServiceCtrlHandlerEx(identname, controlhandler, NULL);
 196
 197         if (!statushandle) {
 198                 logger(LOG_ERR, _("System call `%s' failed: %s"), "RegisterServiceCtrlHandlerEx", winerror(GetLastError()));
 199                 err = 1;
 200         } else {
 201                 status.dwWaitHint = 30000;
 202                 status.dwCurrentState = SERVICE_START_PENDING;
 203                 SetServiceStatus(statushandle, &status);
 204
 205                 status.dwWaitHint = 0;
 206                 status.dwCurrentState = SERVICE_RUNNING;
 207                 SetServiceStatus(statushandle, &status);
 208
 209                 err = main2(argc, argv);
 210
 211                 status.dwWaitHint = 0;
 212                 status.dwCurrentState = SERVICE_STOPPED;
 213                 //status.dwWin32ExitCode = err;
 214                 SetServiceStatus(statushandle, &status);
 215         }
 216
 217         return;
 218 }
 219
 220 bool init_service(void) {
 221         SERVICE_TABLE_ENTRY services[] = {
 222                 {identname, run_service},
 223                 {NULL, NULL}
 224         };
 225
 226         if(!StartServiceCtrlDispatcher(services)) {
 227                 if(GetLastError() == ERROR_FAILED_SERVICE_CONTROLLER_CONNECT) {
 228                         return false;
 229                 }
 230                 else
 231                         logger(LOG_ERR, _("System call `%s' failed: %s"), "StartServiceCtrlDispatcher", winerror(GetLastError()));
 232         }
 233
 234         return true;
 235 }
 236 #endif
 237
 238 #ifndef HAVE_MINGW
 239 /*
 240   check for an existing tinc for this net, and write pid to pidfile
 241 */
 242 static bool write_pidfile(void)
 243 {
 244         pid_t pid;
 245
 246         cp();
 247
 248         pid = check_pid(pidfilename);
 249
 250         if(pid) {
 251                 if(netname)
 252                         fprintf(stderr, _("A tincd is already running for net `%s' with pid %ld.\n"),
 253                                         netname, (long)pid);
 254                 else
 255                         fprintf(stderr, _("A tincd is already running with pid %ld.\n"), (long)pid);
 256                 return false;
 257         }
 258
 259         /* if it's locked, write-protected, or whatever */
 260         if(!write_pid(pidfilename)) {
 261                 fprintf(stderr, _("Could write pid file %s: %s\n"), pidfilename, strerror(errno));
 262                 return false;
 263         }
 264
 265         return true;
 266 }
 267 #endif
 268
 269 /*
 270   kill older tincd for this net
 271 */
 272 bool kill_other(int signal)
 273 {
 274 #ifndef HAVE_MINGW
 275         pid_t pid;
 276
 277         cp();
 278
 279         pid = read_pid(pidfilename);
 280
 281         if(!pid) {
 282                 if(netname)
 283                         fprintf(stderr, _("No other tincd is running for net `%s'.\n"),
 284                                         netname);
 285                 else
 286                         fprintf(stderr, _("No other tincd is running.\n"));
 287                 return false;
 288         }
 289
 290         errno = 0;                                      /* No error, sometimes errno is only changed on error */
 291
 292         /* ESRCH is returned when no process with that pid is found */
 293         if(kill(pid, signal) && errno == ESRCH) {
 294                 if(netname)
 295                         fprintf(stderr, _("The tincd for net `%s' is no longer running. "),
 296                                         netname);
 297                 else
 298                         fprintf(stderr, _("The tincd is no longer running. "));
 299
 300                 fprintf(stderr, _("Removing stale lock file.\n"));
 301                 remove_pid(pidfilename);
 302         }
 303
 304         return true;
 305 #else
 306         return remove_service();
 307 #endif
 308 }
 309
 310 /*
 311   Detach from current terminal, write pidfile, kill parent
 312 */
 313 bool detach(void)
 314 {
 315         cp();
 316
 317         setup_signals();
 318
 319         /* First check if we can open a fresh new pidfile */
 320
 321 #ifndef HAVE_MINGW
 322         if(!write_pidfile())
 323                 return false;
 324
 325         /* If we succeeded in doing that, detach */
 326
 327         closelogger();
 328 #endif
 329
 330         if(do_detach) {
 331 #ifndef HAVE_MINGW
 332                 if(daemon(0, 0)) {
 333                         fprintf(stderr, _("Couldn't detach from terminal: %s"),
 334                                         strerror(errno));
 335                         return false;
 336                 }
 337
 338                 /* Now UPDATE the pid in the pidfile, because we changed it... */
 339
 340                 if(!write_pid(pidfilename)) {
 341                         fprintf(stderr, _("Could not write pid file %s: %s\n"), pidfilename, strerror(errno));
 342                         return false;
 343                 }
 344 #else
 345                 if(!statushandle)
 346                         exit(install_service());
 347 #endif
 348         }
 349
 350         openlogger(identname, use_logfile?LOGMODE_FILE:(do_detach?LOGMODE_SYSLOG:LOGMODE_STDERR));
 351
 352         logger(LOG_NOTICE, _("tincd %s (%s %s) starting, debug level %d"),
 353                            VERSION, __DATE__, __TIME__, debug_level);
 354
 355         xalloc_fail_func = memory_full;
 356
 357         return true;
 358 }
 359
 360 bool execute_script(const char *name, char **envp)
 361 {
 362 #ifdef HAVE_SYSTEM
 363         int status, len;
 364         struct stat s;
 365         char *scriptname, *p;
 366         int i;
 367
 368         cp();
 369
 370 #ifndef HAVE_MINGW
 371         len = asprintf(&scriptname, "\"%s/%s\"", confbase, name);
 372 #else
 373         len = asprintf(&scriptname, "\"%s/%s.bat\"", confbase, name);
 374 #endif
 375         if(len < 0)
 376                 return false;
 377
 378         scriptname[len - 1] = '\0';
 379
 380         /* First check if there is a script */
 381
 382         if(stat(scriptname + 1, &s)) {
 383                 free(scriptname);
 384                 return true;
 385         }
 386
 387         ifdebug(STATUS) logger(LOG_INFO, _("Executing script %s"), name);
 388
 389 #ifdef HAVE_PUTENV
 390         /* Set environment */
 391
 392         for(i = 0; envp[i]; i++)
 393                 putenv(envp[i]);
 394 #endif
 395
 396         scriptname[len - 1] = '\"';
 397         status = system(scriptname);
 398
 399         free(scriptname);
 400
 401         /* Unset environment */
 402
 403         for(i = 0; envp[i]; i++) {
 404                 char *e = strchr(envp[i], '=');
 405                 if(e) {
 406                         p = alloca(e - envp[i] + 1);
 407                         strncpy(p, envp[i], e - envp[i]);
 408                         p[e - envp[i]] = '\0';
 409                         putenv(p);
 410                 }
 411         }
 412
 413 #ifdef WEXITSTATUS
 414         if(status != -1) {
 415                 if(WIFEXITED(status)) { /* Child exited by itself */
 416                         if(WEXITSTATUS(status)) {
 417                                 logger(LOG_ERR, _("Script %s exited with non-zero status %d"),
 418                                            name, WEXITSTATUS(status));
 419                                 return false;
 420                         }
 421                 } else if(WIFSIGNALED(status)) {        /* Child was killed by a signal */
 422                         logger(LOG_ERR, _("Script %s was killed by signal %d (%s)"),
 423                                    name, WTERMSIG(status), strsignal(WTERMSIG(status)));
 424                         return false;
 425                 } else {                        /* Something strange happened */
 426                         logger(LOG_ERR, _("Script %s terminated abnormally"), name);
 427                         return false;
 428                 }
 429         } else {
 430                 logger(LOG_ERR, _("System call `%s' failed: %s"), "system", strerror(errno));
 431                 return false;
 432         }
 433 #endif
 434 #endif
 435         return true;
 436 }
 437
 438
 439 /*
 440   Signal handlers.
 441 */
 442
 443 #ifndef HAVE_MINGW
 444 static RETSIGTYPE sigterm_handler(int a)
 445 {
 446         logger(LOG_NOTICE, _("Got %s signal"), "TERM");
 447         if(running)
 448                 running = false;
 449         else
 450                 exit(1);
 451 }
 452
 453 static RETSIGTYPE sigquit_handler(int a)
 454 {
 455         logger(LOG_NOTICE, _("Got %s signal"), "QUIT");
 456         if(running)
 457                 running = false;
 458         else
 459                 exit(1);
 460 }
 461
 462 static RETSIGTYPE fatal_signal_square(int a)
 463 {
 464         logger(LOG_ERR, _("Got another fatal signal %d (%s): not restarting."), a,
 465                    strsignal(a));
 466         cp_trace();
 467         exit(1);
 468 }
 469
 470 static RETSIGTYPE fatal_signal_handler(int a)
 471 {
 472         struct sigaction act;
 473         logger(LOG_ERR, _("Got fatal signal %d (%s)"), a, strsignal(a));
 474         cp_trace();
 475
 476         if(do_detach) {
 477                 logger(LOG_NOTICE, _("Trying to re-execute in 5 seconds..."));
 478
 479                 act.sa_handler = fatal_signal_square;
 480                 act.sa_mask = emptysigset;
 481                 act.sa_flags = 0;
 482                 sigaction(SIGSEGV, &act, NULL);
 483
 484                 close_network_connections();
 485                 sleep(5);
 486                 remove_pid(pidfilename);
 487                 execvp(g_argv[0], g_argv);
 488         } else {
 489                 logger(LOG_NOTICE, _("Not restarting."));
 490                 exit(1);
 491         }
 492 }
 493
 494 static RETSIGTYPE sighup_handler(int a)
 495 {
 496         logger(LOG_NOTICE, _("Got %s signal"), "HUP");
 497         sighup = true;
 498 }
 499
 500 static RETSIGTYPE sigint_handler(int a)
 501 {
 502         logger(LOG_NOTICE, _("Got %s signal"), "INT");
 503
 504         if(saved_debug_level != -1) {
 505                 logger(LOG_NOTICE, _("Reverting to old debug level (%d)"),
 506                         saved_debug_level);
 507                 debug_level = saved_debug_level;
 508                 saved_debug_level = -1;
 509         } else {
 510                 logger(LOG_NOTICE,
 511                         _("Temporarily setting debug level to 5.  Kill me with SIGINT again to go back to level %d."),
 512                         debug_level);
 513                 saved_debug_level = debug_level;
 514                 debug_level = 5;
 515         }
 516 }
 517
 518 static RETSIGTYPE sigalrm_handler(int a)
 519 {
 520         logger(LOG_NOTICE, _("Got %s signal"), "ALRM");
 521         sigalrm = true;
 522 }
 523
 524 static RETSIGTYPE sigusr1_handler(int a)
 525 {
 526         dump_connections();
 527 }
 528
 529 static RETSIGTYPE sigusr2_handler(int a)
 530 {
 531         dump_device_stats();
 532         dump_nodes();
 533         dump_edges();
 534         dump_subnets();
 535 }
 536
 537 static RETSIGTYPE sigwinch_handler(int a)
 538 {
 539         do_purge = true;
 540 }
 541
 542 static RETSIGTYPE unexpected_signal_handler(int a)
 543 {
 544         logger(LOG_WARNING, _("Got unexpected signal %d (%s)"), a, strsignal(a));
 545         cp_trace();
 546 }
 547
 548 static RETSIGTYPE ignore_signal_handler(int a)
 549 {
 550         ifdebug(SCARY_THINGS) logger(LOG_DEBUG, _("Ignored signal %d (%s)"), a, strsignal(a));
 551 }
 552
 553 static struct {
 554         int signal;
 555         void (*handler)(int);
 556 } sighandlers[] = {
 557         {SIGHUP, sighup_handler},
 558         {SIGTERM, sigterm_handler},
 559         {SIGQUIT, sigquit_handler},
 560         {SIGSEGV, fatal_signal_handler},
 561         {SIGBUS, fatal_signal_handler},
 562         {SIGILL, fatal_signal_handler},
 563         {SIGPIPE, ignore_signal_handler},
 564         {SIGINT, sigint_handler},
 565         {SIGUSR1, sigusr1_handler},
 566         {SIGUSR2, sigusr2_handler},
 567         {SIGCHLD, ignore_signal_handler},
 568         {SIGALRM, sigalrm_handler},
 569         {SIGWINCH, sigwinch_handler},
 570         {0, NULL}
 571 };
 572 #endif
 573
 574 void setup_signals(void)
 575 {
 576 #ifndef HAVE_MINGW
 577         int i;
 578         struct sigaction act;
 579
 580         sigemptyset(&emptysigset);
 581         act.sa_handler = NULL;
 582         act.sa_mask = emptysigset;
 583         act.sa_flags = 0;
 584
 585         /* Set a default signal handler for every signal, errors will be
 586            ignored. */
 587         for(i = 0; i < NSIG; i++) {
 588                 if(!do_detach)
 589                         act.sa_handler = SIG_DFL;
 590                 else
 591                         act.sa_handler = unexpected_signal_handler;
 592                 sigaction(i, &act, NULL);
 593         }
 594
 595         /* If we didn't detach, allow coredumps */
 596         if(!do_detach)
 597                 sighandlers[3].handler = SIG_DFL;
 598
 599         /* Then, for each known signal that we want to catch, assign a
 600            handler to the signal, with error checking this time. */
 601         for(i = 0; sighandlers[i].signal; i++) {
 602                 act.sa_handler = sighandlers[i].handler;
 603                 if(sigaction(sighandlers[i].signal, &act, NULL) < 0)
 604                         fprintf(stderr, _("Installing signal handler for signal %d (%s) failed: %s\n"),
 605                                         sighandlers[i].signal, strsignal(sighandlers[i].signal),
 606                                         strerror(errno));
 607         }
 608 #endif
 609 }