100
101#if !defined(HAVE_EVENT_BASE_GET_METHOD) && (defined(HAVE_EV_LOOP) || defined(HAVE_EV_DEFAULT_LOOP))
102static const char* ev_backend2str(int b)
103{
104 switch(b) {
105 case EVBACKEND_SELECT: return "select";
106 case EVBACKEND_POLL: return "poll";
107 case EVBACKEND_EPOLL: return "epoll";
108 case EVBACKEND_KQUEUE: return "kqueue";
109 case EVBACKEND_DEVPOLL: return "devpoll";
110 case EVBACKEND_PORT: return "evport";
111 }
112 return "unknown";
113}
114#endif
115
116/** get the event system in use */
117static void get_event_sys(const char** n, const char** s, const char** m)
118{
119#ifdef USE_WINSOCK
120 *n = "event";
121 *s = "winsock";
122 *m = "WSAWaitForMultipleEvents";
123#elif defined(USE_MINI_EVENT)
124 *n = "mini-event";
125 *s = "internal";
126 *m = "select";
127#else
128 struct event_base* b;
129 *s = event_get_version();
130# ifdef HAVE_EVENT_BASE_GET_METHOD
131 *n = "libevent";
132 b = event_base_new();
133 *m = event_base_get_method(b);
134# elif defined(HAVE_EV_LOOP) || defined(HAVE_EV_DEFAULT_LOOP)
135 *n = "libev";
136 b = (struct event_base*)ev_default_loop(EVFLAG_AUTO);
137 *m = ev_backend2str(ev_backend((struct ev_loop*)b));
138# else
139 *n = "unknown";
140 *m = "not obtainable";
141 b = NULL;
142# endif
143# ifdef HAVE_EVENT_BASE_FREE
144 event_base_free(b);
145# endif
146#endif
147}
148
149/** print usage. */
150static void usage()
151{
152 const char** m;
153 const char *evnm="event", *evsys="", *evmethod="";
154 printf("usage: unbound [options]\n");
155 printf(" start unbound daemon DNS resolver.\n");
156 printf("-h this help\n");
157 printf("-c file config file to read instead of %s\n", CONFIGFILE);
158 printf(" file format is described in unbound.conf(5).\n");
159 printf("-d do not fork into the background.\n");
160 printf("-v verbose (more times to increase verbosity)\n");
161#ifdef UB_ON_WINDOWS
162 printf("-w opt windows option: \n");
163 printf(" install, remove - manage the services entry\n");
164 printf(" service - used to start from services control panel\n");
165#endif
166 printf("Version %s\n", PACKAGE_VERSION);
167 get_event_sys(&evnm, &evsys, &evmethod);
168 printf("linked libs: %s %s (it uses %s), ldns %s, %s\n",
169 evnm, evsys, evmethod, ldns_version(),
170#ifdef HAVE_SSL
171 SSLeay_version(SSLEAY_VERSION)
172#elif defined(HAVE_NSS)
173 NSS_GetVersion()
174#endif
175 );
176 printf("linked modules:");
177 for(m = module_list_avail(); *m; m++)
178 printf(" %s", *m);
179 printf("\n");
180 printf("configured for %s on %s with options:%s\n",
181 CONFIGURE_TARGET, CONFIGURE_DATE, CONFIGURE_BUILD_WITH);
182 printf("BSD licensed, see LICENSE in source package for details.\n");
183 printf("Report bugs to %s\n", PACKAGE_BUGREPORT);
184}
185
186#ifndef unbound_testbound
187int replay_var_compare(const void* ATTR_UNUSED(a), const void* ATTR_UNUSED(b))
188{
189 log_assert(0);
190 return 0;
191}
192#endif
193
194/** check file descriptor count */
195static void
196checkrlimits(struct config_file* cfg)
197{
198#ifdef HAVE_GETRLIMIT
199 /* list has number of ports to listen to, ifs number addresses */
200 int list = ((cfg->do_udp?1:0) + (cfg->do_tcp?1 +
201 (int)cfg->incoming_num_tcp:0));
202 size_t listen_ifs = (size_t)(cfg->num_ifs==0?
203 ((cfg->do_ip4 && !cfg->if_automatic?1:0) +
204 (cfg->do_ip6?1:0)):cfg->num_ifs);
205 size_t listen_num = list*listen_ifs;
206 size_t outudpnum = (size_t)cfg->outgoing_num_ports;
207 size_t outtcpnum = cfg->outgoing_num_tcp;
208 size_t misc = 4; /* logfile, pidfile, stdout... */
209 size_t perthread_noudp = listen_num + outtcpnum +
210 2/*cmdpipe*/ + 2/*libevent*/ + misc;
211 size_t perthread = perthread_noudp + outudpnum;
212
213#if !defined(HAVE_PTHREAD) && !defined(HAVE_SOLARIS_THREADS)
214 int numthread = 1; /* it forks */
215#else
216 int numthread = (cfg->num_threads?cfg->num_threads:1);
217#endif
218 size_t total = numthread * perthread + misc;
219 size_t avail;
220 struct rlimit rlim;
221
222 if(total > 1024 &&
223 strncmp(event_get_version(), "mini-event", 10) == 0) {
224 log_warn("too many file descriptors requested. The builtin"
225 "mini-event cannot handle more than 1024. Config "
226 "for less fds or compile with libevent");
227 if(numthread*perthread_noudp+15 > 1024)
228 fatal_exit("too much tcp. not enough fds.");
229 cfg->outgoing_num_ports = (int)((1024
230 - numthread*perthread_noudp
231 - 10 /* safety margin */) /numthread);
232 log_warn("continuing with less udp ports: %u",
233 cfg->outgoing_num_ports);
234 total = 1024;
235 }
236 if(perthread > 64 &&
237 strncmp(event_get_version(), "winsock-event", 13) == 0) {
238 log_err("too many file descriptors requested. The winsock"
239 " event handler cannot handle more than 64 per "
240 " thread. Config for less fds");
241 if(perthread_noudp+2 > 64)
242 fatal_exit("too much tcp. not enough fds.");
243 cfg->outgoing_num_ports = (int)((64
244 - perthread_noudp
245 - 2/* safety margin */));
246 log_warn("continuing with less udp ports: %u",
247 cfg->outgoing_num_ports);
248 total = numthread*(perthread_noudp+
249 (size_t)cfg->outgoing_num_ports)+misc;
250 }
251 if(getrlimit(RLIMIT_NOFILE, &rlim) < 0) {
252 log_warn("getrlimit: %s", strerror(errno));
253 return;
254 }
255 if(rlim.rlim_cur == (rlim_t)RLIM_INFINITY)
256 return;
257 if((size_t)rlim.rlim_cur < total) {
258 avail = (size_t)rlim.rlim_cur;
259 rlim.rlim_cur = (rlim_t)(total + 10);
260 rlim.rlim_max = (rlim_t)(total + 10);
261#ifdef HAVE_SETRLIMIT
262 if(setrlimit(RLIMIT_NOFILE, &rlim) < 0) {
263 log_warn("setrlimit: %s", strerror(errno));
264#else
265 if(1) {
266#endif
267 log_warn("cannot increase max open fds from %u to %u",
268 (unsigned)avail, (unsigned)total+10);
269 /* check that calculation below does not underflow,
270 * with 15 as margin */
271 if(numthread*perthread_noudp+15 > avail)
272 fatal_exit("too much tcp. not enough fds.");
273 cfg->outgoing_num_ports = (int)((avail
274 - numthread*perthread_noudp
275 - 10 /* safety margin */) /numthread);
276 log_warn("continuing with less udp ports: %u",
277 cfg->outgoing_num_ports);
278 log_warn("increase ulimit or decrease threads, "
279 "ports in config to remove this warning");
280 return;
281 }
282 log_warn("increased limit(open files) from %u to %u",
283 (unsigned)avail, (unsigned)total+10);
284 }
285#else
286 (void)cfg;
287#endif /* HAVE_GETRLIMIT */
288}
289
290/** set verbosity, check rlimits, cache settings */
291static void
292apply_settings(struct daemon* daemon, struct config_file* cfg,
293 int cmdline_verbose)
294{
295 /* apply if they have changed */
296 verbosity = cmdline_verbose + cfg->verbosity;
297 daemon_apply_cfg(daemon, cfg);
298 checkrlimits(cfg);
299}
300
301#ifdef HAVE_KILL
302/** Read existing pid from pidfile.
303 * @param file: file name of pid file.
304 * @return: the pid from the file or -1 if none.
305 */
306static pid_t
307readpid (const char* file)
308{
309 int fd;
310 pid_t pid;
311 char pidbuf[32];
312 char* t;
313 ssize_t l;
314
315 if ((fd = open(file, O_RDONLY)) == -1) {
316 if(errno != ENOENT)
317 log_err("Could not read pidfile %s: %s",
318 file, strerror(errno));
319 return -1;
320 }
321
322 if (((l = read(fd, pidbuf, sizeof(pidbuf)))) == -1) {
323 if(errno != ENOENT)
324 log_err("Could not read pidfile %s: %s",
325 file, strerror(errno));
326 close(fd);
327 return -1;
328 }
329
330 close(fd);
331
332 /* Empty pidfile means no pidfile... */
333 if (l == 0) {
334 return -1;
335 }
336
337 pidbuf[sizeof(pidbuf)-1] = 0;
338 pid = (pid_t)strtol(pidbuf, &t, 10);
339
340 if (*t && *t != '\n') {
341 return -1;
342 }
343 return pid;
344}
345
346/** write pid to file.
347 * @param pidfile: file name of pid file.
348 * @param pid: pid to write to file.
349 */
350static void
351writepid (const char* pidfile, pid_t pid)
352{
353 FILE* f;
354
355 if ((f = fopen(pidfile, "w")) == NULL ) {
356 log_err("cannot open pidfile %s: %s",
357 pidfile, strerror(errno));
358 return;
359 }
360 if(fprintf(f, "%lu\n", (unsigned long)pid) < 0) {
361 log_err("cannot write to pidfile %s: %s",
362 pidfile, strerror(errno));
363 }
364 fclose(f);
365}
366
367/**
368 * check old pid file.
369 * @param pidfile: the file name of the pid file.
370 * @param inchroot: if pidfile is inchroot and we can thus expect to
371 * be able to delete it.
372 */
373static void
374checkoldpid(char* pidfile, int inchroot)
375{
376 pid_t old;
377 if((old = readpid(pidfile)) != -1) {
378 /* see if it is still alive */
379 if(kill(old, 0) == 0 || errno == EPERM)
380 log_warn("unbound is already running as pid %u.",
381 (unsigned)old);
382 else if(inchroot)
383 log_warn("did not exit gracefully last time (%u)",
384 (unsigned)old);
385 }
386}
387#endif /* HAVE_KILL */
388
389/** detach from command line */
390static void
391detach(void)
392{
393#if defined(HAVE_DAEMON) && !defined(DEPRECATED_DAEMON)
394 /* use POSIX daemon(3) function */
395 if(daemon(1, 0) != 0)
396 fatal_exit("daemon failed: %s", strerror(errno));
397#else /* no HAVE_DAEMON */
398#ifdef HAVE_FORK
399 int fd;
400 /* Take off... */
401 switch (fork()) {
402 case 0:
403 break;
404 case -1:
405 fatal_exit("fork failed: %s", strerror(errno));
406 default:
407 /* exit interactive session */
408 exit(0);
409 }
410 /* detach */
411#ifdef HAVE_SETSID
412 if(setsid() == -1)
413 fatal_exit("setsid() failed: %s", strerror(errno));
414#endif
415 if ((fd = open("/dev/null", O_RDWR, 0)) != -1) {
416 (void)dup2(fd, STDIN_FILENO);
417 (void)dup2(fd, STDOUT_FILENO);
418 (void)dup2(fd, STDERR_FILENO);
419 if (fd > 2)
420 (void)close(fd);
421 }
422#endif /* HAVE_FORK */
423#endif /* HAVE_DAEMON */
424}
425
426/** daemonize, drop user priviliges and chroot if needed */
427static void
428perform_setup(struct daemon* daemon, struct config_file* cfg, int debug_mode,
429 const char** cfgfile)
430{
431#ifdef HAVE_GETPWNAM
432 struct passwd *pwd = NULL;
433 uid_t uid;
434 gid_t gid;
435 /* initialize, but not to 0 (root) */
436 memset(&uid, 112, sizeof(uid));
437 memset(&gid, 112, sizeof(gid));
438 log_assert(cfg);
439
440 if(cfg->username && cfg->username[0]) {
441 if((pwd = getpwnam(cfg->username)) == NULL)
442 fatal_exit("user '%s' does not exist.", cfg->username);
443 uid = pwd->pw_uid;
444 gid = pwd->pw_gid;
445 /* endpwent below, in case we need pwd for setusercontext */
446 }
447#endif
448
449 /* init syslog (as root) if needed, before daemonize, otherwise
450 * a fork error could not be printed since daemonize closed stderr.*/
451 if(cfg->use_syslog) {
452 log_init(cfg->logfile, cfg->use_syslog, cfg->chrootdir);
453 }
454 /* if using a logfile, we cannot open it because the logfile would
455 * be created with the wrong permissions, we cannot chown it because
456 * we cannot chown system logfiles, so we do not open at all.
457 * So, using a logfile, the user does not see errors unless -d is
458 * given to unbound on the commandline. */
459
460 /* read ssl keys while superuser and outside chroot */
461#ifdef HAVE_SSL
462 if(!(daemon->rc = daemon_remote_create(cfg)))
463 fatal_exit("could not set up remote-control");
464 if(cfg->ssl_service_key && cfg->ssl_service_key[0]) {
465 if(!(daemon->listen_sslctx = listen_sslctx_create(
466 cfg->ssl_service_key, cfg->ssl_service_pem, NULL)))
467 fatal_exit("could not set up listen SSL_CTX");
468 }
469 if(!(daemon->connect_sslctx = connect_sslctx_create(NULL, NULL, NULL)))
470 fatal_exit("could not set up connect SSL_CTX");
471#endif
472
473#ifdef HAVE_KILL
474 /* check old pid file before forking */
475 if(cfg->pidfile && cfg->pidfile[0]) {
476 /* calculate position of pidfile */
477 if(cfg->pidfile[0] == '/')
478 daemon->pidfile = strdup(cfg->pidfile);
479 else daemon->pidfile = fname_after_chroot(cfg->pidfile,
480 cfg, 1);
481 if(!daemon->pidfile)
482 fatal_exit("pidfile alloc: out of memory");
483 checkoldpid(daemon->pidfile,
484 /* true if pidfile is inside chrootdir, or nochroot */
485 !(cfg->chrootdir && cfg->chrootdir[0]) ||
486 (cfg->chrootdir && cfg->chrootdir[0] &&
487 strncmp(daemon->pidfile, cfg->chrootdir,
488 strlen(cfg->chrootdir))==0));
489 }
490#endif
491
492 /* daemonize because pid is needed by the writepid func */
493 if(!debug_mode && cfg->do_daemonize) {
494 detach();
495 }
496
497 /* write new pidfile (while still root, so can be outside chroot) */
498#ifdef HAVE_KILL
499 if(cfg->pidfile && cfg->pidfile[0]) {
500 writepid(daemon->pidfile, getpid());
501 if(!(cfg->chrootdir && cfg->chrootdir[0]) ||
502 (cfg->chrootdir && cfg->chrootdir[0] &&
503 strncmp(daemon->pidfile, cfg->chrootdir,
504 strlen(cfg->chrootdir))==0)) {
505 /* delete of pidfile could potentially work,
506 * chown to get permissions */
507 if(cfg->username && cfg->username[0]) {
508 if(chown(daemon->pidfile, uid, gid) == -1) {
509 log_err("cannot chown %u.%u %s: %s",
510 (unsigned)uid, (unsigned)gid,
511 daemon->pidfile, strerror(errno));
512 }
513 }
514 }
515 }
516#else
517 (void)daemon;
518#endif
519
520 /* Set user context */
521#ifdef HAVE_GETPWNAM
522 if(cfg->username && cfg->username[0]) {
523#ifdef HAVE_SETUSERCONTEXT
524 /* setusercontext does initgroups, setuid, setgid, and
525 * also resource limits from login config, but we
526 * still call setresuid, setresgid to be sure to set all uid*/
527 if(setusercontext(NULL, pwd, uid,
528 LOGIN_SETALL & ~LOGIN_SETUSER & ~LOGIN_SETGROUP) != 0)
529 log_warn("unable to setusercontext %s: %s",
530 cfg->username, strerror(errno));
531#endif /* HAVE_SETUSERCONTEXT */
532 }
533#endif /* HAVE_GETPWNAM */
534
535 /* box into the chroot */
536#ifdef HAVE_CHROOT
537 if(cfg->chrootdir && cfg->chrootdir[0]) {
538 if(chdir(cfg->chrootdir)) {
539 fatal_exit("unable to chdir to chroot %s: %s",
540 cfg->chrootdir, strerror(errno));
541 }
542 verbose(VERB_QUERY, "chdir to %s", cfg->chrootdir);
543 if(chroot(cfg->chrootdir))
544 fatal_exit("unable to chroot to %s: %s",
545 cfg->chrootdir, strerror(errno));
546 if(chdir("/"))
547 fatal_exit("unable to chdir to / in chroot %s: %s",
548 cfg->chrootdir, strerror(errno));
549 verbose(VERB_QUERY, "chroot to %s", cfg->chrootdir);
550 if(strncmp(*cfgfile, cfg->chrootdir,
551 strlen(cfg->chrootdir)) == 0)
552 (*cfgfile) += strlen(cfg->chrootdir);
553
554 /* adjust stored pidfile for chroot */
555 if(daemon->pidfile && daemon->pidfile[0] &&
556 strncmp(daemon->pidfile, cfg->chrootdir,
557 strlen(cfg->chrootdir))==0) {
558 char* old = daemon->pidfile;
559 daemon->pidfile = strdup(old+strlen(cfg->chrootdir));
560 free(old);
561 if(!daemon->pidfile)
562 log_err("out of memory in pidfile adjust");
563 }
564 daemon->chroot = strdup(cfg->chrootdir);
565 if(!daemon->chroot)
566 log_err("out of memory in daemon chroot dir storage");
567 }
568#else
569 (void)cfgfile;
570#endif
571 /* change to working directory inside chroot */
572 if(cfg->directory && cfg->directory[0]) {
573 char* dir = cfg->directory;
574 if(cfg->chrootdir && cfg->chrootdir[0] &&
575 strncmp(dir, cfg->chrootdir,
576 strlen(cfg->chrootdir)) == 0)
577 dir += strlen(cfg->chrootdir);
578 if(dir[0]) {
579 if(chdir(dir)) {
580 fatal_exit("Could not chdir to %s: %s",
581 dir, strerror(errno));
582 }
583 verbose(VERB_QUERY, "chdir to %s", dir);
584 }
585 }
586
587 /* drop permissions after chroot, getpwnam, pidfile, syslog done*/
588#ifdef HAVE_GETPWNAM
589 if(cfg->username && cfg->username[0]) {
590# ifdef HAVE_INITGROUPS
591 if(initgroups(cfg->username, gid) != 0)
592 log_warn("unable to initgroups %s: %s",
593 cfg->username, strerror(errno));
594# endif /* HAVE_INITGROUPS */
595 endpwent();
596
597#ifdef HAVE_SETRESGID
598 if(setresgid(gid,gid,gid) != 0)
599#elif defined(HAVE_SETREGID) && !defined(DARWIN_BROKEN_SETREUID)
600 if(setregid(gid,gid) != 0)
601#else /* use setgid */
602 if(setgid(gid) != 0)
603#endif /* HAVE_SETRESGID */
604 fatal_exit("unable to set group id of %s: %s",
605 cfg->username, strerror(errno));
606#ifdef HAVE_SETRESUID
607 if(setresuid(uid,uid,uid) != 0)
608#elif defined(HAVE_SETREUID) && !defined(DARWIN_BROKEN_SETREUID)
609 if(setreuid(uid,uid) != 0)
610#else /* use setuid */
611 if(setuid(uid) != 0)
612#endif /* HAVE_SETRESUID */
613 fatal_exit("unable to set user id of %s: %s",
614 cfg->username, strerror(errno));
615 verbose(VERB_QUERY, "drop user privileges, run as %s",
616 cfg->username);
617 }
618#endif /* HAVE_GETPWNAM */
619 /* file logging inited after chroot,chdir,setuid is done so that
620 * it would succeed on SIGHUP as well */
621 if(!cfg->use_syslog)
622 log_init(cfg->logfile, cfg->use_syslog, cfg->chrootdir);
623}
624
625/**
626 * Run the daemon.
627 * @param cfgfile: the config file name.
628 * @param cmdline_verbose: verbosity resulting from commandline -v.
629 * These increase verbosity as specified in the config file.
630 * @param debug_mode: if set, do not daemonize.
631 */
632static void
633run_daemon(const char* cfgfile, int cmdline_verbose, int debug_mode)
634{
635 struct config_file* cfg = NULL;
636 struct daemon* daemon = NULL;
637 int done_setup = 0;
638
639 if(!(daemon = daemon_init()))
640 fatal_exit("alloc failure");
641 while(!daemon->need_to_exit) {
642 if(done_setup)
643 verbose(VERB_OPS, "Restart of %s.", PACKAGE_STRING);
644 else verbose(VERB_OPS, "Start of %s.", PACKAGE_STRING);
645
646 /* config stuff */
647 if(!(cfg = config_create()))
648 fatal_exit("Could not alloc config defaults");
649 if(!config_read(cfg, cfgfile, daemon->chroot)) {
650 if(errno != ENOENT)
651 fatal_exit("Could not read config file: %s",
652 cfgfile);
653 log_warn("Continuing with default config settings");
654 }
655 apply_settings(daemon, cfg, cmdline_verbose);
656
657 /* prepare */
658 if(!daemon_open_shared_ports(daemon))
659 fatal_exit("could not open ports");
660 if(!done_setup) {
661 perform_setup(daemon, cfg, debug_mode, &cfgfile);
662 done_setup = 1;
663 } else {
664 /* reopen log after HUP to facilitate log rotation */
665 if(!cfg->use_syslog)
666 log_init(cfg->logfile, 0, cfg->chrootdir);
667 }
668 /* work */
669 daemon_fork(daemon);
670
671 /* clean up for restart */
672 verbose(VERB_ALGO, "cleanup.");
673 daemon_cleanup(daemon);
674 config_delete(cfg);
675 }
676 verbose(VERB_ALGO, "Exit cleanup.");
677 /* this unlink may not work if the pidfile is located outside
678 * of the chroot/workdir or we no longer have permissions */
679 if(daemon->pidfile) {
680 int fd;
681 /* truncate pidfile */
682 fd = open(daemon->pidfile, O_WRONLY | O_TRUNC, 0644);
683 if(fd != -1)
684 close(fd);
685 /* delete pidfile */
686 unlink(daemon->pidfile);
687 }
688 daemon_delete(daemon);
689}
690
691/** getopt global, in case header files fail to declare it. */
692extern int optind;
693/** getopt global, in case header files fail to declare it. */
694extern char* optarg;
695
696/**
697 * main program. Set options given commandline arguments.
698 * @param argc: number of commandline arguments.
699 * @param argv: array of commandline arguments.
700 * @return: exit status of the program.
701 */
702int
703main(int argc, char* argv[])
704{
705 int c;
706 const char* cfgfile = CONFIGFILE;
707 const char* winopt = NULL;
708 int cmdline_verbose = 0;
709 int debug_mode = 0;
710#ifdef UB_ON_WINDOWS
711 int cmdline_cfg = 0;
712#endif
713
714#ifdef HAVE_SBRK
715 /* take debug snapshot of heap */
716 unbound_start_brk = sbrk(0);
717#endif
718
719 log_init(NULL, 0, NULL);
720 /* parse the options */
721 while( (c=getopt(argc, argv, "c:dhvw:")) != -1) {
722 switch(c) {
723 case 'c':
724 cfgfile = optarg;
725#ifdef UB_ON_WINDOWS
726 cmdline_cfg = 1;
727#endif
728 break;
729 case 'v':
730 cmdline_verbose ++;
731 verbosity++;
732 break;
733 case 'd':
734 debug_mode = 1;
735 break;
736 case 'w':
737 winopt = optarg;
738 break;
739 case '?':
740 case 'h':
741 default:
742 usage();
743 return 1;
744 }
745 }
746 argc -= optind;
747 argv += optind;
748
749 if(winopt) {
750#ifdef UB_ON_WINDOWS
751 wsvc_command_option(winopt, cfgfile, cmdline_verbose,
752 cmdline_cfg);
753#else
754 fatal_exit("option not supported");
755#endif
756 }
757
758 if(argc != 0) {
759 usage();
760 return 1;
761 }
762
763 run_daemon(cfgfile, cmdline_verbose, debug_mode);
764 log_init(NULL, 0, NULL); /* close logfile */
765 return 0;
766}
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