xref: /freebsd/contrib/ntp/ntpd/ntpd.c (revision 38effe887ee979f91ad5abf42a2291558e7ff8d1)
1 /*
2  * ntpd.c - main program for the fixed point NTP daemon
3  */
4 
5 #ifdef HAVE_CONFIG_H
6 # include <config.h>
7 #endif
8 
9 #include "ntp_machine.h"
10 #include "ntpd.h"
11 #include "ntp_io.h"
12 #include "ntp_stdlib.h"
13 #include <ntp_random.h>
14 
15 #include "ntp_config.h"
16 #include "ntp_syslog.h"
17 #include "ntp_assert.h"
18 #include "isc/error.h"
19 #include "isc/strerror.h"
20 #include "isc/formatcheck.h"
21 #include "iosignal.h"
22 
23 #ifdef SIM
24 # include "ntpsim.h"
25 #endif
26 
27 #include "ntp_libopts.h"
28 #include "ntpd-opts.h"
29 
30 /* there's a short treatise below what the thread stuff is for.
31  * [Bug 2954] enable the threading warm-up only for Linux.
32  */
33 #if defined(HAVE_PTHREADS) && HAVE_PTHREADS && !defined(NO_THREADS)
34 # ifdef HAVE_PTHREAD_H
35 #  include <pthread.h>
36 # endif
37 # if defined(linux)
38 #  define NEED_PTHREAD_WARMUP
39 # endif
40 #endif
41 
42 #ifdef HAVE_UNISTD_H
43 # include <unistd.h>
44 #endif
45 #ifdef HAVE_SYS_STAT_H
46 # include <sys/stat.h>
47 #endif
48 #include <stdio.h>
49 #ifdef HAVE_SYS_PARAM_H
50 # include <sys/param.h>
51 #endif
52 #ifdef HAVE_SYS_SIGNAL_H
53 # include <sys/signal.h>
54 #else
55 # include <signal.h>
56 #endif
57 #ifdef HAVE_SYS_IOCTL_H
58 # include <sys/ioctl.h>
59 #endif /* HAVE_SYS_IOCTL_H */
60 #if defined(HAVE_RTPRIO)
61 # ifdef HAVE_SYS_LOCK_H
62 #  include <sys/lock.h>
63 # endif
64 # include <sys/rtprio.h>
65 #else
66 # ifdef HAVE_PLOCK
67 #  ifdef HAVE_SYS_LOCK_H
68 #	include <sys/lock.h>
69 #  endif
70 # endif
71 #endif
72 #if defined(HAVE_SCHED_SETSCHEDULER)
73 # ifdef HAVE_SCHED_H
74 #  include <sched.h>
75 # else
76 #  ifdef HAVE_SYS_SCHED_H
77 #   include <sys/sched.h>
78 #  endif
79 # endif
80 #endif
81 #if defined(HAVE_SYS_MMAN_H)
82 # include <sys/mman.h>
83 #endif
84 
85 #ifdef HAVE_TERMIOS_H
86 # include <termios.h>
87 #endif
88 
89 #ifdef SYS_DOMAINOS
90 # include <apollo/base.h>
91 #endif /* SYS_DOMAINOS */
92 
93 
94 #include "recvbuff.h"
95 #include "ntp_cmdargs.h"
96 
97 #if 0				/* HMS: I don't think we need this. 961223 */
98 #ifdef LOCK_PROCESS
99 # ifdef SYS_SOLARIS
100 #  include <sys/mman.h>
101 # else
102 #  include <sys/lock.h>
103 # endif
104 #endif
105 #endif
106 
107 #ifdef SYS_WINNT
108 # include "ntservice.h"
109 #endif
110 
111 #ifdef _AIX
112 # include <ulimit.h>
113 #endif /* _AIX */
114 
115 #ifdef SCO5_CLOCK
116 # include <sys/ci/ciioctl.h>
117 #endif
118 
119 #ifdef HAVE_DROPROOT
120 # include <ctype.h>
121 # include <grp.h>
122 # include <pwd.h>
123 #ifdef HAVE_LINUX_CAPABILITIES
124 # include <sys/capability.h>
125 # include <sys/prctl.h>
126 #endif /* HAVE_LINUX_CAPABILITIES */
127 #if defined(HAVE_PRIV_H) && defined(HAVE_SOLARIS_PRIVS)
128 # include <priv.h>
129 #endif /* HAVE_PRIV_H */
130 #if defined(HAVE_TRUSTEDBSD_MAC)
131 # include <sys/mac.h>
132 #endif /* HAVE_TRUSTEDBSD_MAC */
133 #endif /* HAVE_DROPROOT */
134 
135 #if defined (LIBSECCOMP) && (KERN_SECCOMP)
136 /* # include <sys/types.h> */
137 # include <sys/resource.h>
138 # include <seccomp.h>
139 #endif /* LIBSECCOMP and KERN_SECCOMP */
140 
141 #ifdef __FreeBSD__
142 #include <sys/procctl.h>
143 #ifndef PROC_STACKGAP_CTL
144 /*
145  * Even if we compile on an older system we can still run on a newer one.
146  */
147 #define	PROC_STACKGAP_CTL	17
148 #define	PROC_STACKGAP_DISABLE	0x0002
149 #endif
150 #endif
151 
152 #ifdef HAVE_DNSREGISTRATION
153 # include <dns_sd.h>
154 DNSServiceRef mdns;
155 #endif
156 
157 #ifdef HAVE_SETPGRP_0
158 # define ntp_setpgrp(x, y)	setpgrp()
159 #else
160 # define ntp_setpgrp(x, y)	setpgrp(x, y)
161 #endif
162 
163 #ifdef HAVE_SOLARIS_PRIVS
164 # define LOWPRIVS "basic,sys_time,net_privaddr,proc_setid,!proc_info,!proc_session,!proc_exec"
165 static priv_set_t *lowprivs = NULL;
166 static priv_set_t *highprivs = NULL;
167 #endif /* HAVE_SOLARIS_PRIVS */
168 /*
169  * Scheduling priority we run at
170  */
171 #define NTPD_PRIO	(-12)
172 
173 int priority_done = 2;		/* 0 - Set priority */
174 				/* 1 - priority is OK where it is */
175 				/* 2 - Don't set priority */
176 				/* 1 and 2 are pretty much the same */
177 
178 int listen_to_virtual_ips = TRUE;
179 
180 /*
181  * No-fork flag.  If set, we do not become a background daemon.
182  */
183 int nofork;			/* Fork by default */
184 
185 #ifdef HAVE_DNSREGISTRATION
186 /*
187  * mDNS registration flag. If set, we attempt to register with the mDNS system, but only
188  * after we have synched the first time. If the attempt fails, then try again once per
189  * minute for up to 5 times. After all, we may be starting before mDNS.
190  */
191 int mdnsreg = FALSE;
192 int mdnstries = 5;
193 #endif  /* HAVE_DNSREGISTRATION */
194 
195 #ifdef HAVE_DROPROOT
196 int droproot;
197 int root_dropped;
198 char *user;		/* User to switch to */
199 char *group;		/* group to switch to */
200 const char *chrootdir;	/* directory to chroot to */
201 uid_t sw_uid;
202 gid_t sw_gid;
203 struct group *gr;
204 struct passwd *pw;
205 #endif /* HAVE_DROPROOT */
206 
207 #ifdef HAVE_WORKING_FORK
208 int	waitsync_fd_to_close = -1;	/* -w/--wait-sync */
209 #endif
210 
211 /*
212  * Version declaration
213  */
214 extern const char *Version;
215 
216 char const *progname;
217 
218 int was_alarmed;
219 
220 #ifdef DECL_SYSCALL
221 /*
222  * We put this here, since the argument profile is syscall-specific
223  */
224 extern int syscall	(int, ...);
225 #endif /* DECL_SYSCALL */
226 
227 
228 #if !defined(SIM) && defined(SIGDIE1)
229 static volatile int signalled	= 0;
230 static volatile int signo	= 0;
231 
232 /* In an ideal world, 'finish_safe()' would declared as noreturn... */
233 static	void		finish_safe	(int);
234 static	RETSIGTYPE	finish		(int);
235 #endif
236 
237 #if !defined(SIM) && defined(HAVE_WORKING_FORK)
238 static int	wait_child_sync_if	(int, long);
239 #endif
240 
241 #if !defined(SIM) && !defined(SYS_WINNT)
242 # ifdef	DEBUG
243 static	RETSIGTYPE	moredebug	(int);
244 static	RETSIGTYPE	lessdebug	(int);
245 # else	/* !DEBUG follows */
246 static	RETSIGTYPE	no_debug	(int);
247 # endif	/* !DEBUG */
248 #endif	/* !SIM && !SYS_WINNT */
249 
250 #ifndef WORK_FORK
251 int	saved_argc;
252 char **	saved_argv;
253 #endif
254 
255 #ifndef SIM
256 int		ntpdmain		(int, char **);
257 static void	set_process_priority	(void);
258 static void	assertion_failed	(const char *, int,
259 					 isc_assertiontype_t,
260 					 const char *)
261 			__attribute__	((__noreturn__));
262 static void	library_fatal_error	(const char *, int,
263 					 const char *, va_list)
264 					ISC_FORMAT_PRINTF(3, 0);
265 static void	library_unexpected_error(const char *, int,
266 					 const char *, va_list)
267 					ISC_FORMAT_PRINTF(3, 0);
268 #endif	/* !SIM */
269 
270 
271 /* Bug2332 unearthed a problem in the interaction of reduced user
272  * privileges, the limits on memory usage and some versions of the
273  * pthread library on Linux systems. The 'pthread_cancel()' function and
274  * likely some others need to track the stack of the thread involved,
275  * and uses a function that comes from GCC (--> libgcc_s.so) to do
276  * this. Unfortunately the developers of glibc decided to load the
277  * library on demand, which speeds up program start but can cause
278  * trouble here: Due to all the things NTPD does to limit its resource
279  * usage, this deferred load of libgcc_s does not always work once the
280  * restrictions are in effect.
281  *
282  * One way out of this was attempting a forced link against libgcc_s
283  * when possible because it makes the library available immediately
284  * without deferred load. (The symbol resolution would still be dynamic
285  * and on demand, but the code would already be in the process image.)
286  *
287  * This is a tricky thing to do, since it's not necessary everywhere,
288  * not possible everywhere, has shown to break the build of other
289  * programs in the NTP suite and is now generally frowned upon.
290  *
291  * So we take a different approach here: We creat a worker thread that does
292  * actually nothing except waiting for cancellation and cancel it. If
293  * this is done before all the limitations are put in place, the
294  * machinery is pre-heated and all the runtime stuff should be in place
295  * and useable when needed.
296  *
297  * This uses only the standard pthread API and should work with all
298  * implementations of pthreads. It is not necessary everywhere, but it's
299  * cheap enough to go on nearly unnoticed.
300  *
301  * Addendum: Bug 2954 showed that the assumption that this should work
302  * with all OS is wrong -- at least FreeBSD bombs heavily.
303  */
304 #ifdef NEED_PTHREAD_WARMUP
305 
306 /* simple thread function: sleep until cancelled, just to exercise
307  * thread cancellation.
308  */
309 static void*
310 my_pthread_warmup_worker(
311 	void *thread_args)
312 {
313 	(void)thread_args;
314 	for (;;)
315 		sleep(10);
316 	return NULL;
317 }
318 
319 /* pre-heat threading: create a thread and cancel it, just to exercise
320  * thread cancellation.
321  */
322 static void
323 my_pthread_warmup(void)
324 {
325 	pthread_t 	thread;
326 	pthread_attr_t	thr_attr;
327 	int       	rc;
328 
329 	pthread_attr_init(&thr_attr);
330 #if defined(HAVE_PTHREAD_ATTR_GETSTACKSIZE) && \
331     defined(HAVE_PTHREAD_ATTR_SETSTACKSIZE) && \
332     defined(PTHREAD_STACK_MIN)
333 	{
334 		size_t ssmin = 32*1024;	/* 32kB should be minimum */
335 		if (ssmin < PTHREAD_STACK_MIN)
336 			ssmin = PTHREAD_STACK_MIN;
337 		rc = pthread_attr_setstacksize(&thr_attr, ssmin);
338 		if (0 != rc)
339 			msyslog(LOG_ERR,
340 				"my_pthread_warmup: pthread_attr_setstacksize() -> %s",
341 				strerror(rc));
342 	}
343 #endif
344 	rc = pthread_create(
345 		&thread, &thr_attr, my_pthread_warmup_worker, NULL);
346 	pthread_attr_destroy(&thr_attr);
347 	if (0 != rc) {
348 		msyslog(LOG_ERR,
349 			"my_pthread_warmup: pthread_create() -> %s",
350 			strerror(rc));
351 	} else {
352 		pthread_cancel(thread);
353 		pthread_join(thread, NULL);
354 	}
355 }
356 
357 #endif /*defined(NEED_PTHREAD_WARMUP)*/
358 
359 #ifdef NEED_EARLY_FORK
360 static void
361 dummy_callback(void) { return; }
362 
363 static void
364 fork_nonchroot_worker(void) {
365 	getaddrinfo_sometime("localhost", "ntp", NULL, INITIAL_DNS_RETRY,
366 			     (gai_sometime_callback)&dummy_callback, NULL);
367 }
368 #endif /* NEED_EARLY_FORK */
369 
370 void
371 parse_cmdline_opts(
372 	int *	pargc,
373 	char ***pargv
374 	)
375 {
376 	static int	parsed;
377 	static int	optct;
378 
379 	if (!parsed)
380 		optct = ntpOptionProcess(&ntpdOptions, *pargc, *pargv);
381 
382 	parsed = 1;
383 
384 	*pargc -= optct;
385 	*pargv += optct;
386 }
387 
388 
389 #ifdef SIM
390 int
391 main(
392 	int argc,
393 	char *argv[]
394 	)
395 {
396 	progname = argv[0];
397 	parse_cmdline_opts(&argc, &argv);
398 #ifdef DEBUG
399 	debug = OPT_VALUE_SET_DEBUG_LEVEL;
400 	DPRINTF(1, ("%s\n", Version));
401 #endif
402 
403 	return ntpsim(argc, argv);
404 }
405 #else	/* !SIM follows */
406 #ifdef NO_MAIN_ALLOWED
407 CALL(ntpd,"ntpd",ntpdmain);
408 #else	/* !NO_MAIN_ALLOWED follows */
409 #ifndef SYS_WINNT
410 int
411 main(
412 	int argc,
413 	char *argv[]
414 	)
415 {
416 #ifdef __FreeBSD__
417 	{
418 		/*
419 		 * We Must disable ASLR stack gap on FreeBSD to avoid a
420 		 * segfault. See PR/241421 and PR/241960.
421 		 */
422 		int aslr_var = PROC_STACKGAP_DISABLE;
423 
424 		pid_t my_pid = getpid();
425 		procctl(P_PID, my_pid, PROC_STACKGAP_CTL, &aslr_var);
426 	}
427 #endif
428 	return ntpdmain(argc, argv);
429 }
430 #endif /* !SYS_WINNT */
431 #endif /* !NO_MAIN_ALLOWED */
432 #endif /* !SIM */
433 
434 #ifdef _AIX
435 /*
436  * OK. AIX is different than solaris in how it implements plock().
437  * If you do NOT adjust the stack limit, you will get the MAXIMUM
438  * stack size allocated and PINNED with you program. To check the
439  * value, use ulimit -a.
440  *
441  * To fix this, we create an automatic variable and set our stack limit
442  * to that PLUS 32KB of extra space (we need some headroom).
443  *
444  * This subroutine gets the stack address.
445  *
446  * Grover Davidson and Matt Ladendorf
447  *
448  */
449 static char *
450 get_aix_stack(void)
451 {
452 	char ch;
453 	return (&ch);
454 }
455 
456 /*
457  * Signal handler for SIGDANGER.
458  */
459 static void
460 catch_danger(int signo)
461 {
462 	msyslog(LOG_INFO, "ntpd: setpgid(): %m");
463 	/* Make the system believe we'll free something, but don't do it! */
464 	return;
465 }
466 #endif /* _AIX */
467 
468 /*
469  * Set the process priority
470  */
471 #ifndef SIM
472 static void
473 set_process_priority(void)
474 {
475 
476 # ifdef DEBUG
477 	if (debug > 1)
478 		msyslog(LOG_DEBUG, "set_process_priority: %s: priority_done is <%d>",
479 			((priority_done)
480 			 ? "Leave priority alone"
481 			 : "Attempt to set priority"
482 				),
483 			priority_done);
484 # endif /* DEBUG */
485 
486 # if defined(HAVE_SCHED_SETSCHEDULER)
487 	if (!priority_done) {
488 		extern int config_priority_override, config_priority;
489 		int pmax, pmin;
490 		struct sched_param sched;
491 
492 		pmax = sched_get_priority_max(SCHED_FIFO);
493 		sched.sched_priority = pmax;
494 		if ( config_priority_override ) {
495 			pmin = sched_get_priority_min(SCHED_FIFO);
496 			if ( config_priority > pmax )
497 				sched.sched_priority = pmax;
498 			else if ( config_priority < pmin )
499 				sched.sched_priority = pmin;
500 			else
501 				sched.sched_priority = config_priority;
502 		}
503 		if ( sched_setscheduler(0, SCHED_FIFO, &sched) == -1 )
504 			msyslog(LOG_ERR, "sched_setscheduler(): %m");
505 		else
506 			++priority_done;
507 	}
508 # endif /* HAVE_SCHED_SETSCHEDULER */
509 # ifdef HAVE_RTPRIO
510 #  ifdef RTP_SET
511 	if (!priority_done) {
512 		struct rtprio srtp;
513 
514 		srtp.type = RTP_PRIO_REALTIME;	/* was: RTP_PRIO_NORMAL */
515 		srtp.prio = 0;		/* 0 (hi) -> RTP_PRIO_MAX (31,lo) */
516 
517 		if (rtprio(RTP_SET, getpid(), &srtp) < 0)
518 			msyslog(LOG_ERR, "rtprio() error: %m");
519 		else
520 			++priority_done;
521 	}
522 #  else	/* !RTP_SET follows */
523 	if (!priority_done) {
524 		if (rtprio(0, 120) < 0)
525 			msyslog(LOG_ERR, "rtprio() error: %m");
526 		else
527 			++priority_done;
528 	}
529 #  endif	/* !RTP_SET */
530 # endif	/* HAVE_RTPRIO */
531 # if defined(NTPD_PRIO) && NTPD_PRIO != 0
532 #  ifdef HAVE_ATT_NICE
533 	if (!priority_done) {
534 		errno = 0;
535 		if (-1 == nice (NTPD_PRIO) && errno != 0)
536 			msyslog(LOG_ERR, "nice() error: %m");
537 		else
538 			++priority_done;
539 	}
540 #  endif	/* HAVE_ATT_NICE */
541 #  ifdef HAVE_BSD_NICE
542 	if (!priority_done) {
543 		if (-1 == setpriority(PRIO_PROCESS, 0, NTPD_PRIO))
544 			msyslog(LOG_ERR, "setpriority() error: %m");
545 		else
546 			++priority_done;
547 	}
548 #  endif	/* HAVE_BSD_NICE */
549 # endif	/* NTPD_PRIO && NTPD_PRIO != 0 */
550 	if (!priority_done)
551 		msyslog(LOG_ERR, "set_process_priority: No way found to improve our priority");
552 }
553 #endif	/* !SIM */
554 
555 #if !defined(SIM) && !defined(SYS_WINNT)
556 /*
557  * Detach from terminal (much like daemon())
558  * Nothe that this function calls exit()
559  */
560 # ifdef HAVE_WORKING_FORK
561 static void
562 detach_from_terminal(
563 	int pipe_fds[2],
564 	long wait_sync,
565 	const char *logfilename
566 	)
567 {
568 	int rc;
569 	int exit_code;
570 #  if !defined(HAVE_SETSID) && !defined (HAVE_SETPGID) && defined(TIOCNOTTY)
571 	int		fid;
572 #  endif
573 #  ifdef _AIX
574 	struct sigaction sa;
575 #  endif
576 
577 	rc = fork();
578 	if (-1 == rc) {
579 		exit_code = (errno) ? errno : -1;
580 		msyslog(LOG_ERR, "fork: %m");
581 		exit(exit_code);
582 	}
583 	if (rc > 0) {
584 		/* parent */
585 		exit_code = wait_child_sync_if(pipe_fds[0],
586 					       wait_sync);
587 		exit(exit_code);
588 	}
589 
590 	/*
591 	 * child/daemon
592 	 * close all open files excepting waitsync_fd_to_close.
593 	 * msyslog() unreliable until after init_logging().
594 	 */
595 	closelog();
596 	if (syslog_file != NULL) {
597 		fclose(syslog_file);
598 		syslog_file = NULL;
599 		syslogit = TRUE;
600 	}
601 	close_all_except(waitsync_fd_to_close);
602 	INSIST(0 == open("/dev/null", 0) && 1 == dup2(0, 1) \
603 		&& 2 == dup2(0, 2));
604 
605 	init_logging(progname, 0, TRUE);
606 	/* we lost our logfile (if any) daemonizing */
607 	setup_logfile(logfilename);
608 
609 #  ifdef SYS_DOMAINOS
610 	{
611 		uid_$t puid;
612 		status_$t st;
613 
614 		proc2_$who_am_i(&puid);
615 		proc2_$make_server(&puid, &st);
616 	}
617 #  endif	/* SYS_DOMAINOS */
618 #  ifdef HAVE_SETSID
619 	if (setsid() == (pid_t)-1)
620 		msyslog(LOG_ERR, "setsid(): %m");
621 #  elif defined(HAVE_SETPGID)
622 	if (setpgid(0, 0) == -1)
623 		msyslog(LOG_ERR, "setpgid(): %m");
624 #  else		/* !HAVE_SETSID && !HAVE_SETPGID follows */
625 #   ifdef TIOCNOTTY
626 	fid = open("/dev/tty", 2);
627 	if (fid >= 0) {
628 		ioctl(fid, (u_long)TIOCNOTTY, NULL);
629 		close(fid);
630 	}
631 #   endif	/* TIOCNOTTY */
632 	ntp_setpgrp(0, getpid());
633 #  endif	/* !HAVE_SETSID && !HAVE_SETPGID */
634 #  ifdef _AIX
635 	/* Don't get killed by low-on-memory signal. */
636 	sa.sa_handler = catch_danger;
637 	sigemptyset(&sa.sa_mask);
638 	sa.sa_flags = SA_RESTART;
639 	sigaction(SIGDANGER, &sa, NULL);
640 #  endif	/* _AIX */
641 
642 	return;
643 }
644 # endif /* HAVE_WORKING_FORK */
645 
646 #ifdef HAVE_DROPROOT
647 /*
648  * Map user name/number to user ID
649 */
650 static int
651 map_user(
652 	)
653 {
654 	char *endp;
655 
656 	if (isdigit((unsigned char)*user)) {
657 		sw_uid = (uid_t)strtoul(user, &endp, 0);
658 		if (*endp != '\0')
659 			goto getuser;
660 
661 		if ((pw = getpwuid(sw_uid)) != NULL) {
662 			free(user);
663 			user = estrdup(pw->pw_name);
664 			sw_gid = pw->pw_gid;
665 		} else {
666 			errno = 0;
667 			msyslog(LOG_ERR, "Cannot find user ID %s", user);
668 			return 0;
669 		}
670 
671 	} else {
672 getuser:
673 		errno = 0;
674 		if ((pw = getpwnam(user)) != NULL) {
675 			sw_uid = pw->pw_uid;
676 			sw_gid = pw->pw_gid;
677 		} else {
678 			if (errno)
679 				msyslog(LOG_ERR, "getpwnam(%s) failed: %m", user);
680 			else
681 				msyslog(LOG_ERR, "Cannot find user `%s'", user);
682 			return 0;
683 		}
684 	}
685 
686 	return 1;
687 }
688 
689 /*
690  * Map group name/number to group ID
691 */
692 static int
693 map_group(void)
694 {
695 	char *endp;
696 
697 	if (isdigit((unsigned char)*group)) {
698 		sw_gid = (gid_t)strtoul(group, &endp, 0);
699 		if (*endp != '\0')
700 			goto getgroup;
701 	} else {
702 getgroup:
703 		if ((gr = getgrnam(group)) != NULL) {
704 			sw_gid = gr->gr_gid;
705 		} else {
706 			errno = 0;
707 			msyslog(LOG_ERR, "Cannot find group `%s'", group);
708 			return 0;
709 		}
710 	}
711 
712 	return 1;
713 }
714 
715 static int
716 set_group_ids(void)
717 {
718 	if (user && initgroups(user, sw_gid)) {
719 		msyslog(LOG_ERR, "Cannot initgroups() to user `%s': %m", user);
720 		return 0;
721 	}
722 	if (group && setgid(sw_gid)) {
723 		msyslog(LOG_ERR, "Cannot setgid() to group `%s': %m", group);
724 		return 0;
725 	}
726 	if (group && setegid(sw_gid)) {
727 		msyslog(LOG_ERR, "Cannot setegid() to group `%s': %m", group);
728 		return 0;
729 	}
730 	if (group) {
731 		if (0 != setgroups(1, &sw_gid)) {
732 			msyslog(LOG_ERR, "setgroups(1, %d) failed: %m", sw_gid);
733 			return 0;
734 		}
735 	}
736 	else if (pw)
737 		if (0 != initgroups(pw->pw_name, pw->pw_gid)) {
738 			msyslog(LOG_ERR, "initgroups(<%s>, %d) filed: %m", pw->pw_name, pw->pw_gid);
739 			return 0;
740 		}
741 	return 1;
742 }
743 
744 static int
745 set_user_ids(void)
746 {
747 	if (user && setuid(sw_uid)) {
748 		msyslog(LOG_ERR, "Cannot setuid() to user `%s': %m", user);
749 		return 0;
750 	}
751 	if (user && seteuid(sw_uid)) {
752 		msyslog(LOG_ERR, "Cannot seteuid() to user `%s': %m", user);
753 		return 0;
754 	}
755 	return 1;
756 }
757 
758 /*
759  * Change (effective) user and group IDs, also initialize the supplementary group access list
760  */
761 int set_user_group_ids(void);
762 int
763 set_user_group_ids(void)
764 {
765 	/* If the the user was already mapped, no need to map it again */
766 	if ((NULL != user) && (0 == sw_uid)) {
767 		if (0 == map_user())
768 			exit (-1);
769 	}
770 	/* same applies for the group */
771 	if ((NULL != group) && (0 == sw_gid)) {
772 		if (0 == map_group())
773 			exit (-1);
774 	}
775 
776 	if (getegid() != sw_gid && 0 == set_group_ids())
777 		return 0;
778 	if (geteuid() != sw_uid && 0 == set_user_ids())
779 		return 0;
780 
781 	return 1;
782 }
783 #endif /* HAVE_DROPROOT */
784 #endif /* !SIM */
785 
786 /*
787  * Main program.  Initialize us, disconnect us from the tty if necessary,
788  * and loop waiting for I/O and/or timer expiries.
789  */
790 #ifndef SIM
791 int
792 ntpdmain(
793 	int argc,
794 	char *argv[]
795 	)
796 {
797 	l_fp		now;
798 	struct recvbuf *rbuf;
799 	const char *	logfilename;
800 # ifdef HAVE_UMASK
801 	mode_t		uv;
802 # endif
803 # if defined(HAVE_GETUID) && !defined(MPE) /* MPE lacks the concept of root */
804 	uid_t		uid;
805 # endif
806 # if defined(HAVE_WORKING_FORK)
807 	long		wait_sync = 0;
808 	int		pipe_fds[2];
809 	int		rc;
810 	int		exit_code;
811 # endif	/* HAVE_WORKING_FORK*/
812 # ifdef SCO5_CLOCK
813 	int		fd;
814 	int		zero;
815 # endif
816 
817 # ifdef NEED_PTHREAD_WARMUP
818 	my_pthread_warmup();
819 # endif
820 
821 # ifdef HAVE_UMASK
822 	uv = umask(0);
823 	if (uv)
824 		umask(uv);
825 	else
826 		umask(022);
827 # endif
828 	saved_argc = argc;
829 	saved_argv = argv;
830 	progname = argv[0];
831 	initializing = TRUE;		/* mark that we are initializing */
832 	parse_cmdline_opts(&argc, &argv);
833 # ifdef DEBUG
834 	debug = OPT_VALUE_SET_DEBUG_LEVEL;
835 #  ifdef HAVE_SETLINEBUF
836 	setlinebuf(stdout);
837 #  endif
838 # endif
839 
840 	if (HAVE_OPT(NOFORK) || HAVE_OPT(QUIT)
841 # ifdef DEBUG
842 	    || debug
843 # endif
844 	    || HAVE_OPT(SAVECONFIGQUIT))
845 		nofork = TRUE;
846 
847 	init_logging(progname, NLOG_SYNCMASK, TRUE);
848 	/* honor -l/--logfile option to log to a file */
849 	if (HAVE_OPT(LOGFILE)) {
850 		logfilename = OPT_ARG(LOGFILE);
851 		syslogit = FALSE;
852 		change_logfile(logfilename, FALSE);
853 	} else {
854 		logfilename = NULL;
855 		if (nofork)
856 			msyslog_term = TRUE;
857 		if (HAVE_OPT(SAVECONFIGQUIT))
858 			syslogit = FALSE;
859 	}
860 	msyslog(LOG_NOTICE, "%s: Starting", Version);
861 
862 	{
863 		int i;
864 		char buf[1024];	/* Secret knowledge of msyslog buf length */
865 		char *cp = buf;
866 
867 		/* Note that every arg has an initial space character */
868 		snprintf(cp, sizeof(buf), "Command line:");
869 		cp += strlen(cp);
870 
871 		for (i = 0; i < saved_argc ; ++i) {
872 			snprintf(cp, sizeof(buf) - (cp - buf),
873 				" %s", saved_argv[i]);
874 			cp += strlen(cp);
875 		}
876 		msyslog(LOG_INFO, "%s", buf);
877 	}
878 
879 	/*
880 	 * Install trap handlers to log errors and assertion failures.
881 	 * Default handlers print to stderr which doesn't work if detached.
882 	 */
883 	isc_assertion_setcallback(assertion_failed);
884 	isc_error_setfatal(library_fatal_error);
885 	isc_error_setunexpected(library_unexpected_error);
886 
887 	/* MPE lacks the concept of root */
888 # if defined(HAVE_GETUID) && !defined(MPE)
889 	uid = getuid();
890 	if (uid && !HAVE_OPT( SAVECONFIGQUIT )
891 #  if defined(HAVE_TRUSTEDBSD_MAC)
892 	    /* We can run as non-root if the mac_ntpd policy is enabled. */
893 	    && mac_is_present("ntpd") != 1
894 #  endif
895 	    ) {
896 		msyslog_term = TRUE;
897 		msyslog(LOG_ERR,
898 			"must be run as root, not uid %ld", (long)uid);
899 		exit(1);
900 	}
901 # endif
902 
903 /*
904  * Enable the Multi-Media Timer for Windows?
905  */
906 # ifdef SYS_WINNT
907 	if (HAVE_OPT( MODIFYMMTIMER ))
908 		set_mm_timer(MM_TIMER_HIRES);
909 # endif
910 
911 #ifdef HAVE_DNSREGISTRATION
912 /*
913  * Enable mDNS registrations?
914  */
915 	if (HAVE_OPT( MDNS )) {
916 		mdnsreg = TRUE;
917 	}
918 #endif  /* HAVE_DNSREGISTRATION */
919 
920 	if (HAVE_OPT( NOVIRTUALIPS ))
921 		listen_to_virtual_ips = 0;
922 
923 	/*
924 	 * --interface, listen on specified interfaces
925 	 */
926 	if (HAVE_OPT( INTERFACE )) {
927 		int		ifacect = STACKCT_OPT( INTERFACE );
928 		const char**	ifaces  = STACKLST_OPT( INTERFACE );
929 		sockaddr_u	addr;
930 
931 		while (ifacect-- > 0) {
932 			add_nic_rule(
933 				is_ip_address(*ifaces, AF_UNSPEC, &addr)
934 					? MATCH_IFADDR
935 					: MATCH_IFNAME,
936 				*ifaces, -1, ACTION_LISTEN);
937 			ifaces++;
938 		}
939 	}
940 
941 	if (HAVE_OPT( NICE ))
942 		priority_done = 0;
943 
944 # ifdef HAVE_SCHED_SETSCHEDULER
945 	if (HAVE_OPT( PRIORITY )) {
946 		config_priority = OPT_VALUE_PRIORITY;
947 		config_priority_override = 1;
948 		priority_done = 0;
949 	}
950 # endif
951 
952 # ifdef HAVE_WORKING_FORK
953 	/* make sure the FDs are initialised */
954 	pipe_fds[0] = -1;
955 	pipe_fds[1] = -1;
956 	do {					/* 'loop' once */
957 		if (!HAVE_OPT( WAIT_SYNC ))
958 			break;
959 		wait_sync = OPT_VALUE_WAIT_SYNC;
960 		if (wait_sync <= 0) {
961 			wait_sync = 0;
962 			break;
963 		}
964 		/* -w requires a fork() even with debug > 0 */
965 		nofork = FALSE;
966 		if (pipe(pipe_fds)) {
967 			exit_code = (errno) ? errno : -1;
968 			msyslog(LOG_ERR,
969 				"Pipe creation failed for --wait-sync: %m");
970 			exit(exit_code);
971 		}
972 		waitsync_fd_to_close = pipe_fds[1];
973 	} while (0);				/* 'loop' once */
974 # endif	/* HAVE_WORKING_FORK */
975 
976 	init_lib();
977 # ifdef SYS_WINNT
978 	/*
979 	 * Make sure the service is initialized before we do anything else
980 	 */
981 	ntservice_init();
982 
983 	/*
984 	 * Start interpolation thread, must occur before first
985 	 * get_systime()
986 	 */
987 	init_winnt_time();
988 # endif
989 	/*
990 	 * Initialize random generator and public key pair
991 	 */
992 	get_systime(&now);
993 
994 	ntp_srandom((int)(now.l_i * now.l_uf));
995 
996 	/*
997 	 * Detach us from the terminal.  May need an #ifndef GIZMO.
998 	 */
999 	if (!nofork) {
1000 
1001 # ifdef HAVE_WORKING_FORK
1002 		detach_from_terminal(pipe_fds, wait_sync, logfilename);
1003 # endif		/* HAVE_WORKING_FORK */
1004 	}
1005 
1006 # ifdef SCO5_CLOCK
1007 	/*
1008 	 * SCO OpenServer's system clock offers much more precise timekeeping
1009 	 * on the base CPU than the other CPUs (for multiprocessor systems),
1010 	 * so we must lock to the base CPU.
1011 	 */
1012 	fd = open("/dev/at1", O_RDONLY);
1013 	if (fd >= 0) {
1014 		zero = 0;
1015 		if (ioctl(fd, ACPU_LOCK, &zero) < 0)
1016 			msyslog(LOG_ERR, "cannot lock to base CPU: %m");
1017 		close(fd);
1018 	}
1019 # endif
1020 
1021 	/* Setup stack size in preparation for locking pages in memory. */
1022 # if defined(HAVE_MLOCKALL)
1023 #  ifdef HAVE_SETRLIMIT
1024 	ntp_rlimit(RLIMIT_STACK, DFLT_RLIMIT_STACK * 4096, 4096, "4k");
1025 #   if defined(RLIMIT_MEMLOCK) && defined(DFLT_RLIMIT_MEMLOCK) && DFLT_RLIMIT_MEMLOCK != -1
1026 	/*
1027 	 * The default RLIMIT_MEMLOCK is very low on Linux systems.
1028 	 * Unless we increase this limit malloc calls are likely to
1029 	 * fail if we drop root privilege.  To be useful the value
1030 	 * has to be larger than the largest ntpd resident set size.
1031 	 */
1032 	ntp_rlimit(RLIMIT_MEMLOCK, DFLT_RLIMIT_MEMLOCK * 1024 * 1024, 1024 * 1024, "MB");
1033 #   endif	/* RLIMIT_MEMLOCK */
1034 #  endif	/* HAVE_SETRLIMIT */
1035 # else	/* !HAVE_MLOCKALL follows */
1036 #  ifdef HAVE_PLOCK
1037 #   ifdef PROCLOCK
1038 #    ifdef _AIX
1039 	/*
1040 	 * set the stack limit for AIX for plock().
1041 	 * see get_aix_stack() for more info.
1042 	 */
1043 	if (ulimit(SET_STACKLIM, (get_aix_stack() - 8 * 4096)) < 0)
1044 		msyslog(LOG_ERR,
1045 			"Cannot adjust stack limit for plock: %m");
1046 #    endif	/* _AIX */
1047 #   endif	/* PROCLOCK */
1048 #  endif	/* HAVE_PLOCK */
1049 # endif	/* !HAVE_MLOCKALL */
1050 
1051 	/*
1052 	 * Set up signals we pay attention to locally.
1053 	 */
1054 # ifdef SIGDIE1
1055 	signal_no_reset(SIGDIE1, finish);
1056 	signal_no_reset(SIGDIE2, finish);
1057 	signal_no_reset(SIGDIE3, finish);
1058 	signal_no_reset(SIGDIE4, finish);
1059 # endif
1060 # ifdef SIGBUS
1061 	signal_no_reset(SIGBUS, finish);
1062 # endif
1063 
1064 # if !defined(SYS_WINNT) && !defined(VMS)
1065 #  ifdef DEBUG
1066 	(void) signal_no_reset(MOREDEBUGSIG, moredebug);
1067 	(void) signal_no_reset(LESSDEBUGSIG, lessdebug);
1068 #  else
1069 	(void) signal_no_reset(MOREDEBUGSIG, no_debug);
1070 	(void) signal_no_reset(LESSDEBUGSIG, no_debug);
1071 #  endif	/* DEBUG */
1072 # endif	/* !SYS_WINNT && !VMS */
1073 
1074 	/*
1075 	 * Set up signals we should never pay attention to.
1076 	 */
1077 # ifdef SIGPIPE
1078 	signal_no_reset(SIGPIPE, SIG_IGN);
1079 # endif
1080 
1081 	/*
1082 	 * Call the init_ routines to initialize the data structures.
1083 	 *
1084 	 * Exactly what command-line options are we expecting here?
1085 	 */
1086 	INIT_SSL();
1087 	init_auth();
1088 	init_util();
1089 	init_restrict();
1090 	init_mon();
1091 	init_timer();
1092 	init_request();
1093 	init_control();
1094 	init_peer();
1095 # ifdef REFCLOCK
1096 	init_refclock();
1097 # endif
1098 	set_process_priority();
1099 	init_proto();		/* Call at high priority */
1100 	init_io();
1101 	init_loopfilter();
1102 	mon_start(MON_ON);	/* monitor on by default now	  */
1103 				/* turn off in config if unwanted */
1104 
1105 	/*
1106 	 * Get the configuration.  This is done in a separate module
1107 	 * since this will definitely be different for the gizmo board.
1108 	 */
1109 	getconfig(argc, argv);
1110 
1111 	if (-1 == cur_memlock) {
1112 # if defined(HAVE_MLOCKALL)
1113 		/*
1114 		 * lock the process into memory
1115 		 */
1116 		if (   !HAVE_OPT(SAVECONFIGQUIT)
1117 #  ifdef RLIMIT_MEMLOCK
1118 		    && -1 != DFLT_RLIMIT_MEMLOCK
1119 #  endif
1120 		    && 0 != mlockall(MCL_CURRENT|MCL_FUTURE))
1121 			msyslog(LOG_ERR, "mlockall(): %m");
1122 # else	/* !HAVE_MLOCKALL follows */
1123 #  ifdef HAVE_PLOCK
1124 #   ifdef PROCLOCK
1125 		/*
1126 		 * lock the process into memory
1127 		 */
1128 		if (!HAVE_OPT(SAVECONFIGQUIT) && 0 != plock(PROCLOCK))
1129 			msyslog(LOG_ERR, "plock(PROCLOCK): %m");
1130 #   else	/* !PROCLOCK follows  */
1131 #    ifdef TXTLOCK
1132 		/*
1133 		 * Lock text into ram
1134 		 */
1135 		if (!HAVE_OPT(SAVECONFIGQUIT) && 0 != plock(TXTLOCK))
1136 			msyslog(LOG_ERR, "plock(TXTLOCK) error: %m");
1137 #    else	/* !TXTLOCK follows */
1138 		msyslog(LOG_ERR, "plock() - don't know what to lock!");
1139 #    endif	/* !TXTLOCK */
1140 #   endif	/* !PROCLOCK */
1141 #  endif	/* HAVE_PLOCK */
1142 # endif	/* !HAVE_MLOCKALL */
1143 	}
1144 
1145 	loop_config(LOOP_DRIFTINIT, 0);
1146 	report_event(EVNT_SYSRESTART, NULL, NULL);
1147 	initializing = FALSE;
1148 
1149 # ifdef HAVE_DROPROOT
1150 	if (droproot) {
1151 
1152 #ifdef NEED_EARLY_FORK
1153 		fork_nonchroot_worker();
1154 #endif
1155 
1156 		/* Drop super-user privileges and chroot now if the OS supports this */
1157 
1158 #  ifdef HAVE_LINUX_CAPABILITIES
1159 		/* set flag: keep privileges accross setuid() call (we only really need cap_sys_time): */
1160 		if (prctl( PR_SET_KEEPCAPS, 1L, 0L, 0L, 0L ) == -1) {
1161 			msyslog( LOG_ERR, "prctl( PR_SET_KEEPCAPS, 1L ) failed: %m" );
1162 			exit(-1);
1163 		}
1164 #  elif HAVE_SOLARIS_PRIVS
1165 		/* Nothing to do here */
1166 #  else
1167 		/* we need a user to switch to */
1168 		if (user == NULL) {
1169 			msyslog(LOG_ERR, "Need user name to drop root privileges (see -u flag!)" );
1170 			exit(-1);
1171 		}
1172 #  endif	/* HAVE_LINUX_CAPABILITIES || HAVE_SOLARIS_PRIVS */
1173 
1174 		if (user != NULL) {
1175 			if (0 == map_user())
1176 				exit (-1);
1177 		}
1178 		if (group != NULL) {
1179 			if (0 == map_group())
1180 				exit (-1);
1181 		}
1182 
1183 		if (chrootdir ) {
1184 			/* make sure cwd is inside the jail: */
1185 			if (chdir(chrootdir)) {
1186 				msyslog(LOG_ERR, "Cannot chdir() to `%s': %m", chrootdir);
1187 				exit (-1);
1188 			}
1189 			if (chroot(chrootdir)) {
1190 				msyslog(LOG_ERR, "Cannot chroot() to `%s': %m", chrootdir);
1191 				exit (-1);
1192 			}
1193 			if (chdir("/")) {
1194 				msyslog(LOG_ERR, "Cannot chdir() to`root after chroot(): %m");
1195 				exit (-1);
1196 			}
1197 		}
1198 #  ifdef HAVE_SOLARIS_PRIVS
1199 		if ((lowprivs = priv_str_to_set(LOWPRIVS, ",", NULL)) == NULL) {
1200 			msyslog(LOG_ERR, "priv_str_to_set() failed:%m");
1201 			exit(-1);
1202 		}
1203 		if ((highprivs = priv_allocset()) == NULL) {
1204 			msyslog(LOG_ERR, "priv_allocset() failed:%m");
1205 			exit(-1);
1206 		}
1207 		(void) getppriv(PRIV_PERMITTED, highprivs);
1208 		(void) priv_intersect(highprivs, lowprivs);
1209 		if (setppriv(PRIV_SET, PRIV_PERMITTED, lowprivs) == -1) {
1210 			msyslog(LOG_ERR, "setppriv() failed:%m");
1211 			exit(-1);
1212 		}
1213 #  endif /* HAVE_SOLARIS_PRIVS */
1214 		if (0 == set_user_group_ids())
1215 			exit(-1);
1216 
1217 #  if defined(HAVE_TRUSTEDBSD_MAC)
1218 		/*
1219 		 * To manipulate system time and (re-)bind to NTP_PORT as needed
1220 		 * following interface changes, we must either run as uid 0 or
1221 		 * the mac_ntpd policy module must be enabled.
1222 		 */
1223 		if (sw_uid != 0 && mac_is_present("ntpd") != 1) {
1224 			msyslog(LOG_ERR, "Need MAC 'ntpd' policy enabled to drop root privileges");
1225 			exit (-1);
1226 		}
1227 #  elif !defined(HAVE_LINUX_CAPABILITIES) && !defined(HAVE_SOLARIS_PRIVS)
1228 		/*
1229 		 * for now assume that the privilege to bind to privileged ports
1230 		 * is associated with running with uid 0 - should be refined on
1231 		 * ports that allow binding to NTP_PORT with uid != 0
1232 		 */
1233 		disable_dynamic_updates |= (sw_uid != 0);  /* also notifies routing message listener */
1234 #  endif /* !HAVE_LINUX_CAPABILITIES && !HAVE_SOLARIS_PRIVS */
1235 
1236 		if (disable_dynamic_updates && interface_interval) {
1237 			interface_interval = 0;
1238 			msyslog(LOG_INFO, "running as non-root disables dynamic interface tracking");
1239 		}
1240 
1241 #  ifdef HAVE_LINUX_CAPABILITIES
1242 		{
1243 			/*
1244 			 *  We may be running under non-root uid now, but we still hold full root privileges!
1245 			 *  We drop all of them, except for the crucial one or two: cap_sys_time and
1246 			 *  cap_net_bind_service if doing dynamic interface tracking.
1247 			 */
1248 			cap_t caps;
1249 			char *captext;
1250 
1251 			captext = (0 != interface_interval)
1252 				      ? "cap_sys_time,cap_net_bind_service=pe"
1253 				      : "cap_sys_time=pe";
1254 			caps = cap_from_text(captext);
1255 			if (!caps) {
1256 				msyslog(LOG_ERR,
1257 					"cap_from_text(%s) failed: %m",
1258 					captext);
1259 				exit(-1);
1260 			}
1261 			if (-1 == cap_set_proc(caps)) {
1262 				msyslog(LOG_ERR,
1263 					"cap_set_proc() failed to drop root privs: %m");
1264 				exit(-1);
1265 			}
1266 			cap_free(caps);
1267 		}
1268 #  endif	/* HAVE_LINUX_CAPABILITIES */
1269 #  ifdef HAVE_SOLARIS_PRIVS
1270 		if (priv_delset(lowprivs, "proc_setid") == -1) {
1271 			msyslog(LOG_ERR, "priv_delset() failed:%m");
1272 			exit(-1);
1273 		}
1274 		if (setppriv(PRIV_SET, PRIV_PERMITTED, lowprivs) == -1) {
1275 			msyslog(LOG_ERR, "setppriv() failed:%m");
1276 			exit(-1);
1277 		}
1278 		priv_freeset(lowprivs);
1279 		priv_freeset(highprivs);
1280 #  endif /* HAVE_SOLARIS_PRIVS */
1281 		root_dropped = TRUE;
1282 		fork_deferred_worker();
1283 	}	/* if (droproot) */
1284 # endif	/* HAVE_DROPROOT */
1285 
1286 /* libssecomp sandboxing */
1287 #if defined (LIBSECCOMP) && (KERN_SECCOMP)
1288 	scmp_filter_ctx ctx;
1289 
1290 	if ((ctx = seccomp_init(SCMP_ACT_KILL)) < 0)
1291 		msyslog(LOG_ERR, "%s: seccomp_init(SCMP_ACT_KILL) failed: %m", __func__);
1292 	else {
1293 		msyslog(LOG_DEBUG, "%s: seccomp_init(SCMP_ACT_KILL) succeeded", __func__);
1294 	}
1295 
1296 #ifdef __x86_64__
1297 int scmp_sc[] = {
1298 	SCMP_SYS(adjtimex),
1299 	SCMP_SYS(bind),
1300 	SCMP_SYS(brk),
1301 	SCMP_SYS(chdir),
1302 	SCMP_SYS(clock_gettime),
1303 	SCMP_SYS(clock_settime),
1304 	SCMP_SYS(close),
1305 	SCMP_SYS(connect),
1306 	SCMP_SYS(exit_group),
1307 	SCMP_SYS(fstat),
1308 	SCMP_SYS(fsync),
1309 	SCMP_SYS(futex),
1310 	SCMP_SYS(getitimer),
1311 	SCMP_SYS(getsockname),
1312 	SCMP_SYS(ioctl),
1313 	SCMP_SYS(lseek),
1314 	SCMP_SYS(madvise),
1315 	SCMP_SYS(mmap),
1316 	SCMP_SYS(munmap),
1317 	SCMP_SYS(open),
1318 	SCMP_SYS(poll),
1319 	SCMP_SYS(read),
1320 	SCMP_SYS(recvmsg),
1321 	SCMP_SYS(rename),
1322 	SCMP_SYS(rt_sigaction),
1323 	SCMP_SYS(rt_sigprocmask),
1324 	SCMP_SYS(rt_sigreturn),
1325 	SCMP_SYS(select),
1326 	SCMP_SYS(sendto),
1327 	SCMP_SYS(setitimer),
1328 	SCMP_SYS(setsid),
1329 	SCMP_SYS(socket),
1330 	SCMP_SYS(stat),
1331 	SCMP_SYS(time),
1332 	SCMP_SYS(write),
1333 };
1334 #endif
1335 #ifdef __i386__
1336 int scmp_sc[] = {
1337 	SCMP_SYS(_newselect),
1338 	SCMP_SYS(adjtimex),
1339 	SCMP_SYS(brk),
1340 	SCMP_SYS(chdir),
1341 	SCMP_SYS(clock_gettime),
1342 	SCMP_SYS(clock_settime),
1343 	SCMP_SYS(close),
1344 	SCMP_SYS(exit_group),
1345 	SCMP_SYS(fsync),
1346 	SCMP_SYS(futex),
1347 	SCMP_SYS(getitimer),
1348 	SCMP_SYS(madvise),
1349 	SCMP_SYS(mmap),
1350 	SCMP_SYS(mmap2),
1351 	SCMP_SYS(munmap),
1352 	SCMP_SYS(open),
1353 	SCMP_SYS(poll),
1354 	SCMP_SYS(read),
1355 	SCMP_SYS(rename),
1356 	SCMP_SYS(rt_sigaction),
1357 	SCMP_SYS(rt_sigprocmask),
1358 	SCMP_SYS(select),
1359 	SCMP_SYS(setitimer),
1360 	SCMP_SYS(setsid),
1361 	SCMP_SYS(sigprocmask),
1362 	SCMP_SYS(sigreturn),
1363 	SCMP_SYS(socketcall),
1364 	SCMP_SYS(stat64),
1365 	SCMP_SYS(time),
1366 	SCMP_SYS(write),
1367 };
1368 #endif
1369 	{
1370 		int i;
1371 
1372 		for (i = 0; i < COUNTOF(scmp_sc); i++) {
1373 			if (seccomp_rule_add(ctx,
1374 			    SCMP_ACT_ALLOW, scmp_sc[i], 0) < 0) {
1375 				msyslog(LOG_ERR,
1376 				    "%s: seccomp_rule_add() failed: %m",
1377 				    __func__);
1378 			}
1379 		}
1380 	}
1381 
1382 	if (seccomp_load(ctx) < 0)
1383 		msyslog(LOG_ERR, "%s: seccomp_load() failed: %m",
1384 		    __func__);
1385 	else {
1386 		msyslog(LOG_DEBUG, "%s: seccomp_load() succeeded", __func__);
1387 	}
1388 #endif /* LIBSECCOMP and KERN_SECCOMP */
1389 
1390 #ifdef SYS_WINNT
1391 	ntservice_isup();
1392 #endif
1393 
1394 # ifdef HAVE_IO_COMPLETION_PORT
1395 
1396 	for (;;) {
1397 #if !defined(SIM) && defined(SIGDIE1)
1398 		if (signalled)
1399 			finish_safe(signo);
1400 #endif
1401 		GetReceivedBuffers();
1402 # else /* normal I/O */
1403 
1404 	BLOCK_IO_AND_ALARM();
1405 	was_alarmed = FALSE;
1406 
1407 	for (;;) {
1408 #if !defined(SIM) && defined(SIGDIE1)
1409 		if (signalled)
1410 			finish_safe(signo);
1411 #endif
1412 		if (alarm_flag) {	/* alarmed? */
1413 			was_alarmed = TRUE;
1414 			alarm_flag = FALSE;
1415 		}
1416 
1417 		/* collect async name/addr results */
1418 		if (!was_alarmed)
1419 		    harvest_blocking_responses();
1420 
1421 		if (!was_alarmed && !has_full_recv_buffer()) {
1422 			/*
1423 			 * Nothing to do.  Wait for something.
1424 			 */
1425 			io_handler();
1426 		}
1427 
1428 		if (alarm_flag) {	/* alarmed? */
1429 			was_alarmed = TRUE;
1430 			alarm_flag = FALSE;
1431 		}
1432 
1433 		if (was_alarmed) {
1434 			UNBLOCK_IO_AND_ALARM();
1435 			/*
1436 			 * Out here, signals are unblocked.  Call timer routine
1437 			 * to process expiry.
1438 			 */
1439 			timer();
1440 			was_alarmed = FALSE;
1441 			BLOCK_IO_AND_ALARM();
1442 		}
1443 
1444 # endif		/* !HAVE_IO_COMPLETION_PORT */
1445 
1446 # ifdef DEBUG_TIMING
1447 		{
1448 			l_fp pts;
1449 			l_fp tsa, tsb;
1450 			int bufcount = 0;
1451 
1452 			get_systime(&pts);
1453 			tsa = pts;
1454 # endif
1455 			rbuf = get_full_recv_buffer();
1456 			while (rbuf != NULL) {
1457 				if (alarm_flag) {
1458 					was_alarmed = TRUE;
1459 					alarm_flag = FALSE;
1460 				}
1461 				UNBLOCK_IO_AND_ALARM();
1462 
1463 				if (was_alarmed) {
1464 					/* avoid timer starvation during lengthy I/O handling */
1465 					timer();
1466 					was_alarmed = FALSE;
1467 				}
1468 
1469 				/*
1470 				 * Call the data procedure to handle each received
1471 				 * packet.
1472 				 */
1473 				if (rbuf->receiver != NULL) {
1474 # ifdef DEBUG_TIMING
1475 					l_fp dts = pts;
1476 
1477 					L_SUB(&dts, &rbuf->recv_time);
1478 					DPRINTF(2, ("processing timestamp delta %s (with prec. fuzz)\n", lfptoa(&dts, 9)));
1479 					collect_timing(rbuf, "buffer processing delay", 1, &dts);
1480 					bufcount++;
1481 # endif
1482 					(*rbuf->receiver)(rbuf);
1483 				} else {
1484 					msyslog(LOG_ERR, "fatal: receive buffer callback NULL");
1485 					abort();
1486 				}
1487 
1488 				BLOCK_IO_AND_ALARM();
1489 				freerecvbuf(rbuf);
1490 				rbuf = get_full_recv_buffer();
1491 			}
1492 # ifdef DEBUG_TIMING
1493 			get_systime(&tsb);
1494 			L_SUB(&tsb, &tsa);
1495 			if (bufcount) {
1496 				collect_timing(NULL, "processing", bufcount, &tsb);
1497 				DPRINTF(2, ("processing time for %d buffers %s\n", bufcount, lfptoa(&tsb, 9)));
1498 			}
1499 		}
1500 # endif
1501 
1502 		/*
1503 		 * Go around again
1504 		 */
1505 
1506 # ifdef HAVE_DNSREGISTRATION
1507 		if (mdnsreg && (current_time - mdnsreg ) > 60 && mdnstries && sys_leap != LEAP_NOTINSYNC) {
1508 			mdnsreg = current_time;
1509 			msyslog(LOG_INFO, "Attempting to register mDNS");
1510 			if ( DNSServiceRegister (&mdns, 0, 0, NULL, "_ntp._udp", NULL, NULL,
1511 			    htons(NTP_PORT), 0, NULL, NULL, NULL) != kDNSServiceErr_NoError ) {
1512 				if (!--mdnstries) {
1513 					msyslog(LOG_ERR, "Unable to register mDNS, giving up.");
1514 				} else {
1515 					msyslog(LOG_INFO, "Unable to register mDNS, will try later.");
1516 				}
1517 			} else {
1518 				msyslog(LOG_INFO, "mDNS service registered.");
1519 				mdnsreg = FALSE;
1520 			}
1521 		}
1522 # endif /* HAVE_DNSREGISTRATION */
1523 
1524 	}
1525 	UNBLOCK_IO_AND_ALARM();
1526 	return 1;
1527 }
1528 #endif	/* !SIM */
1529 
1530 
1531 #if !defined(SIM) && defined(SIGDIE1)
1532 /*
1533  * finish - exit gracefully
1534  */
1535 static void
1536 finish_safe(
1537 	int	sig
1538 	)
1539 {
1540 	const char *sig_desc;
1541 
1542 	sig_desc = NULL;
1543 #ifdef HAVE_STRSIGNAL
1544 	sig_desc = strsignal(sig);
1545 #endif
1546 	if (sig_desc == NULL)
1547 		sig_desc = "";
1548 	msyslog(LOG_NOTICE, "%s exiting on signal %d (%s)", progname,
1549 		sig, sig_desc);
1550 	/* See Bug 2513 and Bug 2522 re the unlink of PIDFILE */
1551 # ifdef HAVE_DNSREGISTRATION
1552 	if (mdns != NULL)
1553 		DNSServiceRefDeallocate(mdns);
1554 # endif
1555 	peer_cleanup();
1556 	exit(0);
1557 }
1558 
1559 static RETSIGTYPE
1560 finish(
1561 	int	sig
1562 	)
1563 {
1564 	signalled = 1;
1565 	signo = sig;
1566 }
1567 
1568 #endif	/* !SIM && SIGDIE1 */
1569 
1570 
1571 #ifndef SIM
1572 /*
1573  * wait_child_sync_if - implements parent side of -w/--wait-sync
1574  */
1575 # ifdef HAVE_WORKING_FORK
1576 static int
1577 wait_child_sync_if(
1578 	int	pipe_read_fd,
1579 	long	wait_sync
1580 	)
1581 {
1582 	int	rc;
1583 	int	exit_code;
1584 	time_t	wait_end_time;
1585 	time_t	cur_time;
1586 	time_t	wait_rem;
1587 	fd_set	readset;
1588 	struct timeval wtimeout;
1589 
1590 	if (0 == wait_sync)
1591 		return 0;
1592 
1593 	/* waitsync_fd_to_close used solely by child */
1594 	close(waitsync_fd_to_close);
1595 	wait_end_time = time(NULL) + wait_sync;
1596 	do {
1597 		cur_time = time(NULL);
1598 		wait_rem = (wait_end_time > cur_time)
1599 				? (wait_end_time - cur_time)
1600 				: 0;
1601 		wtimeout.tv_sec = wait_rem;
1602 		wtimeout.tv_usec = 0;
1603 		FD_ZERO(&readset);
1604 		FD_SET(pipe_read_fd, &readset);
1605 		rc = select(pipe_read_fd + 1, &readset, NULL, NULL,
1606 			    &wtimeout);
1607 		if (-1 == rc) {
1608 			if (EINTR == errno)
1609 				continue;
1610 			exit_code = (errno) ? errno : -1;
1611 			msyslog(LOG_ERR,
1612 				"--wait-sync select failed: %m");
1613 			return exit_code;
1614 		}
1615 		if (0 == rc) {
1616 			/*
1617 			 * select() indicated a timeout, but in case
1618 			 * its timeouts are affected by a step of the
1619 			 * system clock, select() again with a zero
1620 			 * timeout to confirm.
1621 			 */
1622 			FD_ZERO(&readset);
1623 			FD_SET(pipe_read_fd, &readset);
1624 			wtimeout.tv_sec = 0;
1625 			wtimeout.tv_usec = 0;
1626 			rc = select(pipe_read_fd + 1, &readset, NULL,
1627 				    NULL, &wtimeout);
1628 			if (0 == rc)	/* select() timeout */
1629 				break;
1630 			else		/* readable */
1631 				return 0;
1632 		} else			/* readable */
1633 			return 0;
1634 	} while (wait_rem > 0);
1635 
1636 	fprintf(stderr, "%s: -w/--wait-sync %ld timed out.\n",
1637 		progname, wait_sync);
1638 	return ETIMEDOUT;
1639 }
1640 # endif	/* HAVE_WORKING_FORK */
1641 
1642 
1643 /*
1644  * assertion_failed - Redirect assertion failures to msyslog().
1645  */
1646 static void
1647 assertion_failed(
1648 	const char *file,
1649 	int line,
1650 	isc_assertiontype_t type,
1651 	const char *cond
1652 	)
1653 {
1654 	isc_assertion_setcallback(NULL);    /* Avoid recursion */
1655 
1656 	msyslog(LOG_ERR, "%s:%d: %s(%s) failed",
1657 		file, line, isc_assertion_typetotext(type), cond);
1658 	msyslog(LOG_ERR, "exiting (due to assertion failure)");
1659 
1660 #if defined(DEBUG) && defined(SYS_WINNT)
1661 	if (debug)
1662 		DebugBreak();
1663 #endif
1664 
1665 	abort();
1666 }
1667 
1668 
1669 /*
1670  * library_fatal_error - Handle fatal errors from our libraries.
1671  */
1672 static void
1673 library_fatal_error(
1674 	const char *file,
1675 	int line,
1676 	const char *format,
1677 	va_list args
1678 	)
1679 {
1680 	char errbuf[256];
1681 
1682 	isc_error_setfatal(NULL);  /* Avoid recursion */
1683 
1684 	msyslog(LOG_ERR, "%s:%d: fatal error:", file, line);
1685 	vsnprintf(errbuf, sizeof(errbuf), format, args);
1686 	msyslog(LOG_ERR, "%s", errbuf);
1687 	msyslog(LOG_ERR, "exiting (due to fatal error in library)");
1688 
1689 #if defined(DEBUG) && defined(SYS_WINNT)
1690 	if (debug)
1691 		DebugBreak();
1692 #endif
1693 
1694 	abort();
1695 }
1696 
1697 
1698 /*
1699  * library_unexpected_error - Handle non fatal errors from our libraries.
1700  */
1701 # define MAX_UNEXPECTED_ERRORS 100
1702 int unexpected_error_cnt = 0;
1703 static void
1704 library_unexpected_error(
1705 	const char *file,
1706 	int line,
1707 	const char *format,
1708 	va_list args
1709 	)
1710 {
1711 	char errbuf[256];
1712 
1713 	if (unexpected_error_cnt >= MAX_UNEXPECTED_ERRORS)
1714 		return;	/* avoid clutter in log */
1715 
1716 	msyslog(LOG_ERR, "%s:%d: unexpected error:", file, line);
1717 	vsnprintf(errbuf, sizeof(errbuf), format, args);
1718 	msyslog(LOG_ERR, "%s", errbuf);
1719 
1720 	if (++unexpected_error_cnt == MAX_UNEXPECTED_ERRORS)
1721 		msyslog(LOG_ERR, "Too many errors.  Shutting up.");
1722 
1723 }
1724 #endif	/* !SIM */
1725 
1726 #if !defined(SIM) && !defined(SYS_WINNT)
1727 # ifdef DEBUG
1728 
1729 /*
1730  * moredebug - increase debugging verbosity
1731  */
1732 static RETSIGTYPE
1733 moredebug(
1734 	int sig
1735 	)
1736 {
1737 	int saved_errno = errno;
1738 
1739 	if (debug < 255)
1740 	{
1741 		debug++;
1742 		msyslog(LOG_DEBUG, "debug raised to %d", debug);
1743 	}
1744 	errno = saved_errno;
1745 }
1746 
1747 
1748 /*
1749  * lessdebug - decrease debugging verbosity
1750  */
1751 static RETSIGTYPE
1752 lessdebug(
1753 	int sig
1754 	)
1755 {
1756 	int saved_errno = errno;
1757 
1758 	if (debug > 0)
1759 	{
1760 		debug--;
1761 		msyslog(LOG_DEBUG, "debug lowered to %d", debug);
1762 	}
1763 	errno = saved_errno;
1764 }
1765 
1766 # else	/* !DEBUG follows */
1767 
1768 
1769 /*
1770  * no_debug - We don't do the debug here.
1771  */
1772 static RETSIGTYPE
1773 no_debug(
1774 	int sig
1775 	)
1776 {
1777 	int saved_errno = errno;
1778 
1779 	msyslog(LOG_DEBUG, "ntpd not compiled for debugging (signal %d)", sig);
1780 	errno = saved_errno;
1781 }
1782 # endif	/* !DEBUG */
1783 #endif	/* !SIM && !SYS_WINNT */
1784