src/process.c

   1 /*
   2     process.c -- process management functions
   3     Copyright (C) 1999-2005 Ivo Timmermans,
   4                   2000-2013 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 void memory_full(int size) {
  51         logger(LOG_ERR, "Memory exhausted (couldn't allocate %d bytes), exitting.", size);
  52         exit(1);
  53 }
  54
  55 /* Some functions the less gifted operating systems might lack... */
  56
  57 #ifdef HAVE_MINGW
  58 extern char *identname;
  59 extern char *program_name;
  60 extern char **g_argv;
  61
  62 static SC_HANDLE manager = NULL;
  63 static SC_HANDLE service = NULL;
  64 static SERVICE_STATUS status = {0};
  65 static SERVICE_STATUS_HANDLE statushandle = 0;
  66
  67 bool install_service(void) {
  68         char command[4096] = "\"";
  69         char **argp;
  70         bool space;
  71         SERVICE_DESCRIPTION description = {"Virtual Private Network daemon"};
  72
  73         manager = OpenSCManager(NULL, NULL, SC_MANAGER_ALL_ACCESS);
  74         if(!manager) {
  75                 logger(LOG_ERR, "Could not open service manager: %s", winerror(GetLastError()));
  76                 return false;
  77         }
  78
  79         if(!strchr(program_name, '\\')) {
  80                 GetCurrentDirectory(sizeof command - 1, command + 1);
  81                 strncat(command, "\\", sizeof command - strlen(command));
  82         }
  83
  84         strncat(command, program_name, sizeof command - strlen(command));
  85
  86         strncat(command, "\"", sizeof command - strlen(command));
  87
  88         for(argp = g_argv + 1; *argp; argp++) {
  89                 space = strchr(*argp, ' ');
  90                 strncat(command, " ", sizeof command - strlen(command));
  91
  92                 if(space)
  93                         strncat(command, "\"", sizeof command - strlen(command));
  94
  95                 strncat(command, *argp, sizeof command - strlen(command));
  96
  97                 if(space)
  98                         strncat(command, "\"", sizeof command - strlen(command));
  99         }
 100
 101         service = CreateService(manager, identname, identname,
 102                         SERVICE_ALL_ACCESS, SERVICE_WIN32_OWN_PROCESS, SERVICE_AUTO_START, SERVICE_ERROR_NORMAL,
 103                         command, NULL, NULL, NULL, NULL, NULL);
 104
 105         if(!service) {
 106                 DWORD lasterror = GetLastError();
 107                 logger(LOG_ERR, "Could not create %s service: %s", identname, winerror(lasterror));
 108                 if(lasterror != ERROR_SERVICE_EXISTS)
 109                         return false;
 110         }
 111
 112         if(service) {
 113                 ChangeServiceConfig2(service, SERVICE_CONFIG_DESCRIPTION, &description);
 114                 logger(LOG_INFO, "%s service installed", identname);
 115         } else {
 116                 service = OpenService(manager, identname, SERVICE_ALL_ACCESS);
 117         }
 118
 119         if(!StartService(service, 0, NULL))
 120                 logger(LOG_WARNING, "Could not start %s service: %s", identname, winerror(GetLastError()));
 121         else
 122                 logger(LOG_INFO, "%s service started", identname);
 123
 124         return true;
 125 }
 126
 127 bool remove_service(void) {
 128         manager = OpenSCManager(NULL, NULL, SC_MANAGER_ALL_ACCESS);
 129         if(!manager) {
 130                 logger(LOG_ERR, "Could not open service manager: %s", winerror(GetLastError()));
 131                 return false;
 132         }
 133
 134         service = OpenService(manager, identname, SERVICE_ALL_ACCESS);
 135
 136         if(!service) {
 137                 logger(LOG_ERR, "Could not open %s service: %s", identname, winerror(GetLastError()));
 138                 return false;
 139         }
 140
 141         if(!ControlService(service, SERVICE_CONTROL_STOP, &status))
 142                 logger(LOG_ERR, "Could not stop %s service: %s", identname, winerror(GetLastError()));
 143         else
 144                 logger(LOG_INFO, "%s service stopped", identname);
 145
 146         if(!DeleteService(service)) {
 147                 logger(LOG_ERR, "Could not remove %s service: %s", identname, winerror(GetLastError()));
 148                 return false;
 149         }
 150
 151         logger(LOG_INFO, "%s service removed", identname);
 152
 153         return true;
 154 }
 155
 156 DWORD WINAPI controlhandler(DWORD request, DWORD type, LPVOID boe, LPVOID bah) {
 157         switch(request) {
 158                 case SERVICE_CONTROL_INTERROGATE:
 159                         SetServiceStatus(statushandle, &status);
 160                         return NO_ERROR;
 161                 case SERVICE_CONTROL_STOP:
 162                         logger(LOG_NOTICE, "Got %s request", "SERVICE_CONTROL_STOP");
 163                         break;
 164                 case SERVICE_CONTROL_SHUTDOWN:
 165                         logger(LOG_NOTICE, "Got %s request", "SERVICE_CONTROL_SHUTDOWN");
 166                         break;
 167                 default:
 168                         logger(LOG_WARNING, "Got unexpected request %d", (int)request);
 169                         return ERROR_CALL_NOT_IMPLEMENTED;
 170         }
 171
 172         if(running) {
 173                 running = false;
 174                 status.dwWaitHint = 30000;
 175                 status.dwCurrentState = SERVICE_STOP_PENDING;
 176                 SetServiceStatus(statushandle, &status);
 177                 return NO_ERROR;
 178         } else {
 179                 status.dwWaitHint = 0;
 180                 status.dwCurrentState = SERVICE_STOPPED;
 181                 SetServiceStatus(statushandle, &status);
 182                 exit(1);
 183         }
 184
 185 }
 186
 187 VOID WINAPI run_service(DWORD argc, LPTSTR* argv) {
 188         extern int main2(int argc, char **argv);
 189
 190         status.dwServiceType = SERVICE_WIN32;
 191         status.dwControlsAccepted = SERVICE_ACCEPT_STOP | SERVICE_ACCEPT_SHUTDOWN;
 192         status.dwWin32ExitCode = 0;
 193         status.dwServiceSpecificExitCode = 0;
 194         status.dwCheckPoint = 0;
 195
 196         statushandle = RegisterServiceCtrlHandlerEx(identname, controlhandler, NULL);
 197
 198         if (!statushandle) {
 199                 logger(LOG_ERR, "System call `%s' failed: %s", "RegisterServiceCtrlHandlerEx", winerror(GetLastError()));
 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                 main2(argc, argv);
 210
 211                 status.dwWaitHint = 0;
 212                 status.dwCurrentState = SERVICE_STOPPED;
 213                 SetServiceStatus(statushandle, &status);
 214         }
 215
 216         return;
 217 }
 218
 219 bool init_service(void) {
 220         SERVICE_TABLE_ENTRY services[] = {
 221                 {identname, run_service},
 222                 {NULL, NULL}
 223         };
 224
 225         if(!StartServiceCtrlDispatcher(services)) {
 226                 if(GetLastError() == ERROR_FAILED_SERVICE_CONTROLLER_CONNECT) {
 227                         return false;
 228                 }
 229                 else
 230                         logger(LOG_ERR, "System call `%s' failed: %s", "StartServiceCtrlDispatcher", winerror(GetLastError()));
 231         }
 232
 233         return true;
 234 }
 235 #endif
 236
 237 #ifndef HAVE_MINGW
 238 /*
 239   check for an existing tinc for this net, and write pid to pidfile
 240 */
 241 static bool write_pidfile(void) {
 242         pid_t pid;
 243
 244         pid = check_pid(pidfilename);
 245
 246         if(pid) {
 247                 if(netname)
 248                         fprintf(stderr, "A tincd is already running for net `%s' with pid %ld.\n",
 249                                         netname, (long)pid);
 250                 else
 251                         fprintf(stderr, "A tincd is already running with pid %ld.\n", (long)pid);
 252                 return false;
 253         }
 254
 255         /* if it's locked, write-protected, or whatever */
 256         if(!write_pid(pidfilename)) {
 257                 fprintf(stderr, "Couldn't write pid file %s: %s\n", pidfilename, strerror(errno));
 258                 return false;
 259         }
 260
 261         return true;
 262 }
 263 #endif
 264
 265 /*
 266   kill older tincd for this net
 267 */
 268 bool kill_other(int signal) {
 269 #ifndef HAVE_MINGW
 270         pid_t pid;
 271
 272         pid = read_pid(pidfilename);
 273
 274         if(!pid) {
 275                 if(netname)
 276                         fprintf(stderr, "No other tincd is running for net `%s'.\n",
 277                                         netname);
 278                 else
 279                         fprintf(stderr, "No other tincd is running.\n");
 280                 return false;
 281         }
 282
 283         errno = 0;                                      /* No error, sometimes errno is only changed on error */
 284
 285         /* ESRCH is returned when no process with that pid is found */
 286         if(kill(pid, signal) && errno == ESRCH) {
 287                 if(netname)
 288                         fprintf(stderr, "The tincd for net `%s' is no longer running. ",
 289                                         netname);
 290                 else
 291                         fprintf(stderr, "The tincd is no longer running. ");
 292
 293                 fprintf(stderr, "Removing stale lock file.\n");
 294                 remove_pid(pidfilename);
 295         }
 296
 297         return true;
 298 #else
 299         return remove_service();
 300 #endif
 301 }
 302
 303 /*
 304   Detach from current terminal, write pidfile, kill parent
 305 */
 306 bool detach(void) {
 307         setup_signals();
 308
 309         /* First check if we can open a fresh new pidfile */
 310
 311 #ifndef HAVE_MINGW
 312         if(!write_pidfile())
 313                 return false;
 314
 315         /* If we succeeded in doing that, detach */
 316
 317         closelogger();
 318 #endif
 319
 320         if(do_detach) {
 321 #ifndef HAVE_MINGW
 322                 if(daemon(0, 0)) {
 323                         fprintf(stderr, "Couldn't detach from terminal: %s",
 324                                         strerror(errno));
 325                         return false;
 326                 }
 327
 328                 /* Now UPDATE the pid in the pidfile, because we changed it... */
 329
 330                 if(!write_pid(pidfilename)) {
 331                         fprintf(stderr, "Could not write pid file %s: %s\n", pidfilename, strerror(errno));
 332                         return false;
 333                 }
 334 #else
 335                 if(!statushandle)
 336                         exit(install_service());
 337 #endif
 338         }
 339
 340         openlogger(identname, use_logfile?LOGMODE_FILE:(do_detach?LOGMODE_SYSLOG:LOGMODE_STDERR));
 341
 342         logger(LOG_NOTICE, "tincd %s (%s %s) starting, debug level %d",
 343                            VERSION, __DATE__, __TIME__, debug_level);
 344
 345         xalloc_fail_func = memory_full;
 346
 347         return true;
 348 }
 349
 350 #ifdef HAVE_PUTENV
 351 void unputenv(char *p) {
 352         char *e = strchr(p, '=');
 353         if(!e)
 354                 return;
 355         int len = e - p;
 356 #ifndef HAVE_UNSETENV
 357 #ifdef HAVE_MINGW
 358         // Windows requires putenv("FOO=") to unset %FOO%
 359         len++;
 360 #endif
 361 #endif
 362         char var[len];
 363         strncpy(var, p, len);
 364 #ifdef HAVE_UNSETENV
 365         unsetenv(var);
 366 #else
 367         // We must keep what we putenv() around in memory.
 368         // To do this without memory leaks, keep things in a list and reuse if possible.
 369         static list_t list = {};
 370         for(list_node_t *node = list->head; node; node++) {
 371                 char *data = node->data;
 372                 if(!strcmp(data, var)) {
 373                         putenv(data);
 374                         return;
 375                 }
 376         }
 377         char *data = strcmp(var);
 378         list_insert_tail(list, data);
 379         putenv(data);
 380 #endif
 381 }
 382 #else
 383 void putenv(const char *p) {}
 384 void unputenv(const char *p) {}
 385 #endif
 386
 387 bool execute_script(const char *name, char **envp) {
 388 #ifdef HAVE_SYSTEM
 389         char *scriptname;
 390         char *interpreter = NULL;
 391         config_t *cfg_interpreter;
 392         int status, len, i;
 393
 394         cfg_interpreter = lookup_config(config_tree, "ScriptsInterpreter");
 395 #ifndef HAVE_MINGW
 396         len = xasprintf(&scriptname, "\"%s/%s\"", confbase, name);
 397 #else
 398         if(cfg_interpreter)
 399                 len = xasprintf(&scriptname, "\"%s/%s\"", confbase, name);
 400         else
 401                 len = xasprintf(&scriptname, "\"%s/%s.bat\"", confbase, name);
 402 #endif
 403         if(len < 0)
 404                 return false;
 405
 406         scriptname[len - 1] = '\0';
 407
 408         /* First check if there is a script */
 409         if(access(scriptname + 1, F_OK)) {
 410                 free(scriptname);
 411                 return true;
 412         }
 413
 414         // Custom scripts interpreter
 415         if(get_config_string(cfg_interpreter, &interpreter)) {
 416                 // Force custom scripts interpreter allowing execution of scripts on android without execution flag (such as on /sdcard)
 417                 free(scriptname);
 418                 len = xasprintf(&scriptname, "%s \"%s/%s\"", interpreter, confbase, name);
 419                 free(interpreter);
 420                 if(len < 0)
 421                         return false;
 422         }
 423
 424         ifdebug(STATUS) logger(LOG_INFO, "Executing script %s", name);
 425
 426         /* Set environment */
 427
 428         for(i = 0; envp[i]; i++)
 429                 putenv(envp[i]);
 430
 431         scriptname[len - 1] = '\"';
 432         status = system(scriptname);
 433
 434         free(scriptname);
 435
 436         /* Unset environment */
 437
 438         for(i = 0; envp[i]; i++)
 439                 unputenv(envp[i]);
 440
 441         if(status != -1) {
 442 #ifdef WEXITSTATUS
 443                 if(WIFEXITED(status)) { /* Child exited by itself */
 444                         if(WEXITSTATUS(status)) {
 445                                 logger(LOG_ERR, "Script %s exited with non-zero status %d",
 446                                            name, WEXITSTATUS(status));
 447                                 return false;
 448                         }
 449                 } else if(WIFSIGNALED(status)) {        /* Child was killed by a signal */
 450                         logger(LOG_ERR, "Script %s was killed by signal %d (%s)",
 451                                    name, WTERMSIG(status), strsignal(WTERMSIG(status)));
 452                         return false;
 453                 } else {                        /* Something strange happened */
 454                         logger(LOG_ERR, "Script %s terminated abnormally", name);
 455                         return false;
 456                 }
 457 #endif
 458         } else {
 459                 logger(LOG_ERR, "System call `%s' failed: %s", "system", strerror(errno));
 460                 return false;
 461         }
 462 #endif
 463         return true;
 464 }
 465
 466
 467 /*
 468   Signal handlers.
 469 */
 470
 471 #ifndef HAVE_MINGW
 472 static RETSIGTYPE sigterm_handler(int a) {
 473         logger(LOG_NOTICE, "Got %s signal", "TERM");
 474         if(running)
 475                 running = false;
 476         else
 477                 exit(1);
 478 }
 479
 480 static RETSIGTYPE sigquit_handler(int a) {
 481         logger(LOG_NOTICE, "Got %s signal", "QUIT");
 482         if(running)
 483                 running = false;
 484         else
 485                 exit(1);
 486 }
 487
 488 static RETSIGTYPE fatal_signal_square(int a) {
 489         logger(LOG_ERR, "Got another fatal signal %d (%s): not restarting.", a,
 490                    strsignal(a));
 491         exit(1);
 492 }
 493
 494 static RETSIGTYPE fatal_signal_handler(int a) {
 495         struct sigaction act;
 496         logger(LOG_ERR, "Got fatal signal %d (%s)", a, strsignal(a));
 497
 498         if(do_detach) {
 499                 logger(LOG_NOTICE, "Trying to re-execute in 5 seconds...");
 500
 501                 act.sa_handler = fatal_signal_square;
 502                 act.sa_mask = emptysigset;
 503                 act.sa_flags = 0;
 504                 sigaction(SIGSEGV, &act, NULL);
 505
 506                 close_network_connections();
 507                 sleep(5);
 508                 remove_pid(pidfilename);
 509                 execvp(g_argv[0], g_argv);
 510         } else {
 511                 logger(LOG_NOTICE, "Not restarting.");
 512                 exit(1);
 513         }
 514 }
 515
 516 static RETSIGTYPE sighup_handler(int a) {
 517         logger(LOG_NOTICE, "Got %s signal", "HUP");
 518         sighup = true;
 519 }
 520
 521 static RETSIGTYPE sigint_handler(int a) {
 522         static int saved_debug_level = -1;
 523
 524         logger(LOG_NOTICE, "Got %s signal", "INT");
 525
 526         if(saved_debug_level != -1) {
 527                 logger(LOG_NOTICE, "Reverting to old debug level (%d)",
 528                         saved_debug_level);
 529                 debug_level = saved_debug_level;
 530                 saved_debug_level = -1;
 531         } else {
 532                 logger(LOG_NOTICE,
 533                         "Temporarily setting debug level to 5.  Kill me with SIGINT again to go back to level %d.",
 534                         debug_level);
 535                 saved_debug_level = debug_level;
 536                 debug_level = 5;
 537         }
 538 }
 539
 540 static RETSIGTYPE sigalrm_handler(int a) {
 541         logger(LOG_NOTICE, "Got %s signal", "ALRM");
 542         sigalrm = true;
 543 }
 544
 545 static RETSIGTYPE sigusr1_handler(int a) {
 546         dump_connections();
 547 }
 548
 549 static RETSIGTYPE sigusr2_handler(int a) {
 550         devops.dump_stats();
 551         dump_nodes();
 552         dump_edges();
 553         dump_subnets();
 554 }
 555
 556 static RETSIGTYPE sigwinch_handler(int a) {
 557         do_purge = true;
 558 }
 559
 560 static RETSIGTYPE unexpected_signal_handler(int a) {
 561         logger(LOG_WARNING, "Got unexpected signal %d (%s)", a, strsignal(a));
 562 }
 563
 564 static RETSIGTYPE ignore_signal_handler(int a) {
 565         ifdebug(SCARY_THINGS) logger(LOG_DEBUG, "Ignored signal %d (%s)", a, strsignal(a));
 566 }
 567
 568 static struct {
 569         int signal;
 570         void (*handler)(int);
 571 } sighandlers[] = {
 572         {SIGHUP, sighup_handler},
 573         {SIGTERM, sigterm_handler},
 574         {SIGQUIT, sigquit_handler},
 575         {SIGSEGV, fatal_signal_handler},
 576         {SIGBUS, fatal_signal_handler},
 577         {SIGILL, fatal_signal_handler},
 578         {SIGPIPE, ignore_signal_handler},
 579         {SIGINT, sigint_handler},
 580         {SIGUSR1, sigusr1_handler},
 581         {SIGUSR2, sigusr2_handler},
 582         {SIGCHLD, ignore_signal_handler},
 583         {SIGALRM, sigalrm_handler},
 584         {SIGWINCH, sigwinch_handler},
 585         {SIGABRT, SIG_DFL},
 586         {0, NULL}
 587 };
 588 #endif
 589
 590 void setup_signals(void) {
 591 #ifndef HAVE_MINGW
 592         int i;
 593         struct sigaction act;
 594
 595         sigemptyset(&emptysigset);
 596         act.sa_handler = NULL;
 597         act.sa_mask = emptysigset;
 598         act.sa_flags = 0;
 599
 600         /* Set a default signal handler for every signal, errors will be
 601            ignored. */
 602         for(i = 1; i < NSIG; i++) {
 603                 if(!do_detach)
 604                         act.sa_handler = SIG_DFL;
 605                 else
 606                         act.sa_handler = unexpected_signal_handler;
 607                 sigaction(i, &act, NULL);
 608         }
 609
 610         /* If we didn't detach, allow coredumps */
 611         if(!do_detach)
 612                 sighandlers[3].handler = SIG_DFL;
 613
 614         /* Then, for each known signal that we want to catch, assign a
 615            handler to the signal, with error checking this time. */
 616         for(i = 0; sighandlers[i].signal; i++) {
 617                 act.sa_handler = sighandlers[i].handler;
 618                 if(sigaction(sighandlers[i].signal, &act, NULL) < 0)
 619                         fprintf(stderr, "Installing signal handler for signal %d (%s) failed: %s\n",
 620                                         sighandlers[i].signal, strsignal(sighandlers[i].signal),
 621                                         strerror(errno));
 622         }
 623 #endif
 624 }