src/process.c

   1 /*
   2     process.c -- process management functions
   3     Copyright (C) 1999-2005 Ivo Timmermans,
   4                   2000-2015 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 /* Some functions the less gifted operating systems might lack... */
  51
  52 #ifdef HAVE_MINGW
  53 extern char *identname;
  54 extern char *program_name;
  55 extern char **g_argv;
  56
  57 static SC_HANDLE manager = NULL;
  58 static SC_HANDLE service = NULL;
  59 static SERVICE_STATUS status = {0};
  60 static SERVICE_STATUS_HANDLE statushandle = 0;
  61
  62 bool install_service(void) {
  63         char command[4096] = "\"";
  64         char **argp;
  65         bool space;
  66         SERVICE_DESCRIPTION description = {"Virtual Private Network daemon"};
  67
  68         manager = OpenSCManager(NULL, NULL, SC_MANAGER_ALL_ACCESS);
  69         if(!manager) {
  70                 logger(LOG_ERR, "Could not open service manager: %s", winerror(GetLastError()));
  71                 return false;
  72         }
  73
  74         if(!strchr(program_name, '\\')) {
  75                 GetCurrentDirectory(sizeof command - 1, command + 1);
  76                 strncat(command, "\\", sizeof command - strlen(command));
  77         }
  78
  79         strncat(command, program_name, sizeof command - strlen(command));
  80
  81         strncat(command, "\"", sizeof command - strlen(command));
  82
  83         for(argp = g_argv + 1; *argp; argp++) {
  84                 space = strchr(*argp, ' ');
  85                 strncat(command, " ", sizeof command - strlen(command));
  86
  87                 if(space)
  88                         strncat(command, "\"", sizeof command - strlen(command));
  89
  90                 strncat(command, *argp, sizeof command - strlen(command));
  91
  92                 if(space)
  93                         strncat(command, "\"", sizeof command - strlen(command));
  94         }
  95
  96         service = CreateService(manager, identname, identname,
  97                         SERVICE_ALL_ACCESS, SERVICE_WIN32_OWN_PROCESS, SERVICE_AUTO_START, SERVICE_ERROR_NORMAL,
  98                         command, NULL, NULL, NULL, NULL, NULL);
  99
 100         if(!service) {
 101                 DWORD lasterror = GetLastError();
 102                 logger(LOG_ERR, "Could not create %s service: %s", identname, winerror(lasterror));
 103                 if(lasterror != ERROR_SERVICE_EXISTS)
 104                         return false;
 105         }
 106
 107         if(service) {
 108                 ChangeServiceConfig2(service, SERVICE_CONFIG_DESCRIPTION, &description);
 109                 logger(LOG_INFO, "%s service installed", identname);
 110         } else {
 111                 service = OpenService(manager, identname, SERVICE_ALL_ACCESS);
 112         }
 113
 114         if(!StartService(service, 0, NULL))
 115                 logger(LOG_WARNING, "Could not start %s service: %s", identname, winerror(GetLastError()));
 116         else
 117                 logger(LOG_INFO, "%s service started", identname);
 118
 119         return true;
 120 }
 121
 122 bool remove_service(void) {
 123         manager = OpenSCManager(NULL, NULL, SC_MANAGER_ALL_ACCESS);
 124         if(!manager) {
 125                 logger(LOG_ERR, "Could not open service manager: %s", winerror(GetLastError()));
 126                 return false;
 127         }
 128
 129         service = OpenService(manager, identname, SERVICE_ALL_ACCESS);
 130
 131         if(!service) {
 132                 logger(LOG_ERR, "Could not open %s service: %s", identname, winerror(GetLastError()));
 133                 return false;
 134         }
 135
 136         if(!ControlService(service, SERVICE_CONTROL_STOP, &status))
 137                 logger(LOG_ERR, "Could not stop %s service: %s", identname, winerror(GetLastError()));
 138         else
 139                 logger(LOG_INFO, "%s service stopped", identname);
 140
 141         if(!DeleteService(service)) {
 142                 logger(LOG_ERR, "Could not remove %s service: %s", identname, winerror(GetLastError()));
 143                 return false;
 144         }
 145
 146         logger(LOG_INFO, "%s service removed", identname);
 147
 148         return true;
 149 }
 150
 151 DWORD WINAPI controlhandler(DWORD request, DWORD type, LPVOID boe, LPVOID bah) {
 152         switch(request) {
 153                 case SERVICE_CONTROL_INTERROGATE:
 154                         SetServiceStatus(statushandle, &status);
 155                         return NO_ERROR;
 156                 case SERVICE_CONTROL_STOP:
 157                         logger(LOG_NOTICE, "Got %s request", "SERVICE_CONTROL_STOP");
 158                         break;
 159                 case SERVICE_CONTROL_SHUTDOWN:
 160                         logger(LOG_NOTICE, "Got %s request", "SERVICE_CONTROL_SHUTDOWN");
 161                         break;
 162                 default:
 163                         logger(LOG_WARNING, "Got unexpected request %d", (int)request);
 164                         return ERROR_CALL_NOT_IMPLEMENTED;
 165         }
 166
 167         if(running) {
 168                 running = false;
 169                 status.dwWaitHint = 30000;
 170                 status.dwCurrentState = SERVICE_STOP_PENDING;
 171                 SetServiceStatus(statushandle, &status);
 172                 return NO_ERROR;
 173         } else {
 174                 status.dwWaitHint = 0;
 175                 status.dwCurrentState = SERVICE_STOPPED;
 176                 SetServiceStatus(statushandle, &status);
 177                 exit(1);
 178         }
 179
 180 }
 181
 182 VOID WINAPI run_service(DWORD argc, LPTSTR* argv) {
 183         extern int main2(int argc, char **argv);
 184
 185         status.dwServiceType = SERVICE_WIN32;
 186         status.dwControlsAccepted = SERVICE_ACCEPT_STOP | SERVICE_ACCEPT_SHUTDOWN;
 187         status.dwWin32ExitCode = 0;
 188         status.dwServiceSpecificExitCode = 0;
 189         status.dwCheckPoint = 0;
 190
 191         statushandle = RegisterServiceCtrlHandlerEx(identname, controlhandler, NULL);
 192
 193         if (!statushandle) {
 194                 logger(LOG_ERR, "System call `%s' failed: %s", "RegisterServiceCtrlHandlerEx", winerror(GetLastError()));
 195         } else {
 196                 status.dwWaitHint = 30000;
 197                 status.dwCurrentState = SERVICE_START_PENDING;
 198                 SetServiceStatus(statushandle, &status);
 199
 200                 status.dwWaitHint = 0;
 201                 status.dwCurrentState = SERVICE_RUNNING;
 202                 SetServiceStatus(statushandle, &status);
 203
 204                 main2(argc, argv);
 205
 206                 status.dwWaitHint = 0;
 207                 status.dwCurrentState = SERVICE_STOPPED;
 208                 SetServiceStatus(statushandle, &status);
 209         }
 210
 211         return;
 212 }
 213
 214 bool init_service(void) {
 215         SERVICE_TABLE_ENTRY services[] = {
 216                 {identname, run_service},
 217                 {NULL, NULL}
 218         };
 219
 220         if(!StartServiceCtrlDispatcher(services)) {
 221                 if(GetLastError() == ERROR_FAILED_SERVICE_CONTROLLER_CONNECT) {
 222                         return false;
 223                 }
 224                 else
 225                         logger(LOG_ERR, "System call `%s' failed: %s", "StartServiceCtrlDispatcher", winerror(GetLastError()));
 226         }
 227
 228         return true;
 229 }
 230 #endif
 231
 232 #ifndef HAVE_MINGW
 233 /*
 234   check for an existing tinc for this net, and write pid to pidfile
 235 */
 236 static bool write_pidfile(void) {
 237         pid_t pid;
 238
 239         pid = check_pid(pidfilename);
 240
 241         if(pid) {
 242                 if(netname)
 243                         fprintf(stderr, "A tincd is already running for net `%s' with pid %ld.\n",
 244                                         netname, (long)pid);
 245                 else
 246                         fprintf(stderr, "A tincd is already running with pid %ld.\n", (long)pid);
 247                 return false;
 248         }
 249
 250         /* if it's locked, write-protected, or whatever */
 251         if(!write_pid(pidfilename)) {
 252                 fprintf(stderr, "Couldn't write pid file %s: %s\n", pidfilename, strerror(errno));
 253                 return false;
 254         }
 255
 256         return true;
 257 }
 258 #endif
 259
 260 /*
 261   kill older tincd for this net
 262 */
 263 bool kill_other(int signal) {
 264 #ifndef HAVE_MINGW
 265         pid_t pid;
 266
 267         pid = read_pid(pidfilename);
 268
 269         if(!pid) {
 270                 if(netname)
 271                         fprintf(stderr, "No other tincd is running for net `%s'.\n",
 272                                         netname);
 273                 else
 274                         fprintf(stderr, "No other tincd is running.\n");
 275                 return false;
 276         }
 277
 278         errno = 0;                                      /* No error, sometimes errno is only changed on error */
 279
 280         /* ESRCH is returned when no process with that pid is found */
 281         if(kill(pid, signal) && errno == ESRCH) {
 282                 if(netname)
 283                         fprintf(stderr, "The tincd for net `%s' is no longer running. ",
 284                                         netname);
 285                 else
 286                         fprintf(stderr, "The tincd is no longer running. ");
 287
 288                 fprintf(stderr, "Removing stale lock file.\n");
 289                 remove_pid(pidfilename);
 290         }
 291
 292         return true;
 293 #else
 294         return remove_service();
 295 #endif
 296 }
 297
 298 /*
 299   Detach from current terminal, write pidfile, kill parent
 300 */
 301 bool detach(void) {
 302         setup_signals();
 303
 304         /* First check if we can open a fresh new pidfile */
 305
 306 #ifndef HAVE_MINGW
 307         if(!write_pidfile())
 308                 return false;
 309
 310         /* If we succeeded in doing that, detach */
 311
 312         closelogger();
 313 #endif
 314
 315         if(do_detach) {
 316 #ifndef HAVE_MINGW
 317                 if(daemon(0, 0)) {
 318                         fprintf(stderr, "Couldn't detach from terminal: %s",
 319                                         strerror(errno));
 320                         return false;
 321                 }
 322
 323                 /* Now UPDATE the pid in the pidfile, because we changed it... */
 324
 325                 if(!write_pid(pidfilename)) {
 326                         fprintf(stderr, "Could not write pid file %s: %s\n", pidfilename, strerror(errno));
 327                         return false;
 328                 }
 329 #else
 330                 if(!statushandle)
 331                         exit(install_service());
 332 #endif
 333         }
 334
 335         openlogger(identname, use_logfile?LOGMODE_FILE:(do_detach?LOGMODE_SYSLOG:LOGMODE_STDERR));
 336
 337         logger(LOG_NOTICE, "tincd %s starting, debug level %d",
 338                            VERSION, debug_level);
 339
 340         return true;
 341 }
 342
 343 #ifdef HAVE_PUTENV
 344 void unputenv(char *p) {
 345         char *e = strchr(p, '=');
 346         if(!e)
 347                 return;
 348         int len = e - p;
 349 #ifndef HAVE_UNSETENV
 350 #ifdef HAVE_MINGW
 351         // Windows requires putenv("FOO=") to unset %FOO%
 352         len++;
 353 #endif
 354 #endif
 355         char var[len + 1];
 356         memcpy(var, p, len);
 357         var[len] = 0;
 358 #ifdef HAVE_UNSETENV
 359         unsetenv(var);
 360 #else
 361         // We must keep what we putenv() around in memory.
 362         // To do this without memory leaks, keep things in a list and reuse if possible.
 363         static list_t list = {};
 364         for(list_node_t *node = list.head; node; node = node->next) {
 365                 char *data = node->data;
 366                 if(!strcmp(data, var)) {
 367                         putenv(data);
 368                         return;
 369                 }
 370         }
 371         char *data = xstrdup(var);
 372         list_insert_tail(&list, data);
 373         putenv(data);
 374 #endif
 375 }
 376 #else
 377 void putenv(const char *p) {}
 378 void unputenv(const char *p) {}
 379 #endif
 380
 381 bool execute_script(const char *name, char **envp) {
 382 #ifdef HAVE_SYSTEM
 383         char *scriptname;
 384         char *interpreter = NULL;
 385         config_t *cfg_interpreter;
 386         int status, len, i;
 387
 388         cfg_interpreter = lookup_config(config_tree, "ScriptsInterpreter");
 389 #ifndef HAVE_MINGW
 390         len = xasprintf(&scriptname, "\"%s/%s\"", confbase, name);
 391 #else
 392         if(cfg_interpreter)
 393                 len = xasprintf(&scriptname, "\"%s/%s\"", confbase, name);
 394         else
 395                 len = xasprintf(&scriptname, "\"%s/%s.bat\"", confbase, name);
 396 #endif
 397         if(len < 0)
 398                 return false;
 399
 400         scriptname[len - 1] = '\0';
 401
 402         /* First check if there is a script */
 403         if(access(scriptname + 1, F_OK)) {
 404                 free(scriptname);
 405                 return true;
 406         }
 407
 408         // Custom scripts interpreter
 409         if(get_config_string(cfg_interpreter, &interpreter)) {
 410                 // Force custom scripts interpreter allowing execution of scripts on android without execution flag (such as on /sdcard)
 411                 free(scriptname);
 412                 len = xasprintf(&scriptname, "%s \"%s/%s\"", interpreter, confbase, name);
 413                 free(interpreter);
 414                 if(len < 0)
 415                         return false;
 416         }
 417
 418         ifdebug(STATUS) logger(LOG_INFO, "Executing script %s", name);
 419
 420         /* Set environment */
 421
 422         for(i = 0; envp[i]; i++)
 423                 putenv(envp[i]);
 424
 425         scriptname[len - 1] = '\"';
 426         status = system(scriptname);
 427
 428         free(scriptname);
 429
 430         /* Unset environment */
 431
 432         for(i = 0; envp[i]; i++)
 433                 unputenv(envp[i]);
 434
 435         if(status != -1) {
 436 #ifdef WEXITSTATUS
 437                 if(WIFEXITED(status)) { /* Child exited by itself */
 438                         if(WEXITSTATUS(status)) {
 439                                 logger(LOG_ERR, "Script %s exited with non-zero status %d",
 440                                            name, WEXITSTATUS(status));
 441                                 return false;
 442                         }
 443                 } else if(WIFSIGNALED(status)) {        /* Child was killed by a signal */
 444                         logger(LOG_ERR, "Script %s was killed by signal %d (%s)",
 445                                    name, WTERMSIG(status), strsignal(WTERMSIG(status)));
 446                         return false;
 447                 } else {                        /* Something strange happened */
 448                         logger(LOG_ERR, "Script %s terminated abnormally", name);
 449                         return false;
 450                 }
 451 #endif
 452         } else {
 453                 logger(LOG_ERR, "System call `%s' failed: %s", "system", strerror(errno));
 454                 return false;
 455         }
 456 #endif
 457         return true;
 458 }
 459
 460
 461 /*
 462   Signal handlers.
 463 */
 464
 465 #ifndef HAVE_MINGW
 466 static RETSIGTYPE sigterm_handler(int a) {
 467         logger(LOG_NOTICE, "Got %s signal", "TERM");
 468         if(running)
 469                 running = false;
 470         else
 471                 exit(1);
 472 }
 473
 474 static RETSIGTYPE sigquit_handler(int a) {
 475         logger(LOG_NOTICE, "Got %s signal", "QUIT");
 476         if(running)
 477                 running = false;
 478         else
 479                 exit(1);
 480 }
 481
 482 static RETSIGTYPE fatal_signal_square(int a) {
 483         logger(LOG_ERR, "Got another fatal signal %d (%s): not restarting.", a,
 484                    strsignal(a));
 485         exit(1);
 486 }
 487
 488 static RETSIGTYPE fatal_signal_handler(int a) {
 489         struct sigaction act;
 490         logger(LOG_ERR, "Got fatal signal %d (%s)", a, strsignal(a));
 491
 492         if(do_detach) {
 493                 logger(LOG_NOTICE, "Trying to re-execute in 5 seconds...");
 494
 495                 act.sa_handler = fatal_signal_square;
 496                 act.sa_mask = emptysigset;
 497                 act.sa_flags = 0;
 498                 sigaction(SIGSEGV, &act, NULL);
 499
 500                 close_network_connections();
 501                 sleep(5);
 502                 remove_pid(pidfilename);
 503                 execvp(g_argv[0], g_argv);
 504         } else {
 505                 logger(LOG_NOTICE, "Not restarting.");
 506                 exit(1);
 507         }
 508 }
 509
 510 static RETSIGTYPE sighup_handler(int a) {
 511         logger(LOG_NOTICE, "Got %s signal", "HUP");
 512         sighup = true;
 513 }
 514
 515 static RETSIGTYPE sigint_handler(int a) {
 516         static int saved_debug_level = -1;
 517
 518         logger(LOG_NOTICE, "Got %s signal", "INT");
 519
 520         if(saved_debug_level != -1) {
 521                 logger(LOG_NOTICE, "Reverting to old debug level (%d)",
 522                         saved_debug_level);
 523                 debug_level = saved_debug_level;
 524                 saved_debug_level = -1;
 525         } else {
 526                 logger(LOG_NOTICE,
 527                         "Temporarily setting debug level to 5.  Kill me with SIGINT again to go back to level %d.",
 528                         debug_level);
 529                 saved_debug_level = debug_level;
 530                 debug_level = 5;
 531         }
 532 }
 533
 534 static RETSIGTYPE sigalrm_handler(int a) {
 535         logger(LOG_NOTICE, "Got %s signal", "ALRM");
 536         sigalrm = true;
 537 }
 538
 539 static RETSIGTYPE sigusr1_handler(int a) {
 540         dump_connections();
 541 }
 542
 543 static RETSIGTYPE sigusr2_handler(int a) {
 544         devops.dump_stats();
 545         dump_nodes();
 546         dump_edges();
 547         dump_subnets();
 548 }
 549
 550 static RETSIGTYPE sigwinch_handler(int a) {
 551         do_purge = true;
 552 }
 553
 554 static RETSIGTYPE unexpected_signal_handler(int a) {
 555         logger(LOG_WARNING, "Got unexpected signal %d (%s)", a, strsignal(a));
 556 }
 557
 558 static RETSIGTYPE ignore_signal_handler(int a) {
 559         ifdebug(SCARY_THINGS) logger(LOG_DEBUG, "Ignored signal %d (%s)", a, strsignal(a));
 560 }
 561
 562 static struct {
 563         int signal;
 564         void (*handler)(int);
 565 } sighandlers[] = {
 566         {SIGHUP, sighup_handler},
 567         {SIGTERM, sigterm_handler},
 568         {SIGQUIT, sigquit_handler},
 569         {SIGSEGV, fatal_signal_handler},
 570         {SIGBUS, fatal_signal_handler},
 571         {SIGILL, fatal_signal_handler},
 572         {SIGPIPE, ignore_signal_handler},
 573         {SIGINT, sigint_handler},
 574         {SIGUSR1, sigusr1_handler},
 575         {SIGUSR2, sigusr2_handler},
 576         {SIGCHLD, ignore_signal_handler},
 577         {SIGALRM, sigalrm_handler},
 578         {SIGWINCH, sigwinch_handler},
 579         {SIGABRT, SIG_DFL},
 580         {0, NULL}
 581 };
 582 #endif
 583
 584 void setup_signals(void) {
 585 #ifndef HAVE_MINGW
 586         int i;
 587         struct sigaction act;
 588
 589         sigemptyset(&emptysigset);
 590         act.sa_handler = NULL;
 591         act.sa_mask = emptysigset;
 592         act.sa_flags = 0;
 593
 594         /* Set a default signal handler for every signal, errors will be
 595            ignored. */
 596         for(i = 1; i < NSIG; i++) {
 597                 if(!do_detach)
 598                         act.sa_handler = SIG_DFL;
 599                 else
 600                         act.sa_handler = unexpected_signal_handler;
 601                 sigaction(i, &act, NULL);
 602         }
 603
 604         /* If we didn't detach, allow coredumps */
 605         if(!do_detach)
 606                 sighandlers[3].handler = SIG_DFL;
 607
 608         /* Then, for each known signal that we want to catch, assign a
 609            handler to the signal, with error checking this time. */
 610         for(i = 0; sighandlers[i].signal; i++) {
 611                 act.sa_handler = sighandlers[i].handler;
 612                 if(sigaction(sighandlers[i].signal, &act, NULL) < 0)
 613                         fprintf(stderr, "Installing signal handler for signal %d (%s) failed: %s\n",
 614                                         sighandlers[i].signal, strsignal(sighandlers[i].signal),
 615                                         strerror(errno));
 616         }
 617 #endif
 618 }