xref: /freebsd/contrib/ntp/ntpd/ntp_timer.c (revision f81cdf24ba5436367377f7c8e8f51f6df2a75ca7)
1 /*
2  * ntp_timer.c - event timer support routines
3  */
4 #ifdef HAVE_CONFIG_H
5 # include <config.h>
6 #endif
7 
8 #include "ntp_machine.h"
9 #include "ntpd.h"
10 #include "ntp_stdlib.h"
11 #include "ntp_calendar.h"
12 #include "ntp_leapsec.h"
13 
14 #if defined(HAVE_IO_COMPLETION_PORT)
15 # include "ntp_iocompletionport.h"
16 # include "ntp_timer.h"
17 #endif
18 
19 #include <stdio.h>
20 #include <signal.h>
21 #ifdef HAVE_SYS_SIGNAL_H
22 # include <sys/signal.h>
23 #endif
24 #ifdef HAVE_UNISTD_H
25 # include <unistd.h>
26 #endif
27 
28 #ifdef KERNEL_PLL
29 #include "ntp_syscall.h"
30 #endif /* KERNEL_PLL */
31 
32 #ifdef AUTOKEY
33 #include <openssl/rand.h>
34 #endif	/* AUTOKEY */
35 
36 
37 /* TC_ERR represents the timer_create() error return value. */
38 #ifdef SYS_VXWORKS
39 #define	TC_ERR	ERROR
40 #else
41 #define	TC_ERR	(-1)
42 #endif
43 
44 
45 static void check_leapsec(u_int32, const time_t*, int/*BOOL*/);
46 
47 /*
48  * These routines provide support for the event timer.  The timer is
49  * implemented by an interrupt routine which sets a flag once every
50  * second, and a timer routine which is called when the mainline code
51  * gets around to seeing the flag.  The timer routine dispatches the
52  * clock adjustment code if its time has come, then searches the timer
53  * queue for expiries which are dispatched to the transmit procedure.
54  * Finally, we call the hourly procedure to do cleanup and print a
55  * message.
56  */
57 volatile int interface_interval;     /* init_io() sets def. 300s */
58 
59 /*
60  * Initializing flag.  All async routines watch this and only do their
61  * thing when it is clear.
62  */
63 int initializing;
64 
65 /*
66  * Alarm flag. The mainline code imports this.
67  */
68 volatile int alarm_flag;
69 
70 /*
71  * The counters and timeouts
72  */
73 static  u_long interface_timer;	/* interface update timer */
74 static	u_long adjust_timer;	/* second timer */
75 static	u_long stats_timer;	/* stats timer */
76 static	u_long leapf_timer;	/* Report leapfile problems once/day */
77 static	u_long huffpuff_timer;	/* huff-n'-puff timer */
78 static	u_long worker_idle_timer;/* next check for idle intres */
79 u_long	leapsec;	        /* seconds to next leap (proximity class) */
80 int     leapdif;                /* TAI difference step at next leap second*/
81 u_long	orphwait; 		/* orphan wait time */
82 #ifdef AUTOKEY
83 static	u_long revoke_timer;	/* keys revoke timer */
84 static	u_long keys_timer;	/* session key timer */
85 u_char	sys_revoke = KEY_REVOKE; /* keys revoke timeout (log2 s) */
86 u_char	sys_automax = NTP_AUTOMAX; /* key list timeout (log2 s) */
87 #endif	/* AUTOKEY */
88 
89 /*
90  * Statistics counter for the interested.
91  */
92 volatile u_long alarm_overflow;
93 
94 u_long current_time;		/* seconds since startup */
95 
96 /*
97  * Stats.  Number of overflows and number of calls to transmit().
98  */
99 u_long timer_timereset;
100 u_long timer_overflows;
101 u_long timer_xmtcalls;
102 
103 #if defined(VMS)
104 static int vmstimer[2]; 	/* time for next timer AST */
105 static int vmsinc[2];		/* timer increment */
106 #endif /* VMS */
107 
108 #ifdef SYS_WINNT
109 HANDLE WaitableTimerHandle;
110 #else
111 static	RETSIGTYPE alarming (int);
112 #endif /* SYS_WINNT */
113 
114 #if !defined(VMS)
115 # if !defined SYS_WINNT || defined(SYS_CYGWIN32)
116 #  ifdef HAVE_TIMER_CREATE
117 static timer_t timer_id;
118 typedef struct itimerspec intervaltimer;
119 #   define	itv_frac	tv_nsec
120 #  else
121 typedef struct itimerval intervaltimer;
122 #   define	itv_frac	tv_usec
123 #  endif
124 intervaltimer itimer;
125 # endif
126 #endif
127 
128 #if !defined(SYS_WINNT) && !defined(VMS)
129 void	set_timer_or_die(const intervaltimer *);
130 #endif
131 
132 
133 #if !defined(SYS_WINNT) && !defined(VMS)
134 void
135 set_timer_or_die(
136 	const intervaltimer *	ptimer
137 	)
138 {
139 	const char *	setfunc;
140 	int		rc;
141 
142 # ifdef HAVE_TIMER_CREATE
143 	setfunc = "timer_settime";
144 	rc = timer_settime(timer_id, 0, &itimer, NULL);
145 # else
146 	setfunc = "setitimer";
147 	rc = setitimer(ITIMER_REAL, &itimer, NULL);
148 # endif
149 	if (-1 == rc) {
150 		msyslog(LOG_ERR, "interval timer %s failed, %m",
151 			setfunc);
152 		exit(1);
153 	}
154 }
155 #endif	/* !SYS_WINNT && !VMS */
156 
157 
158 /*
159  * reinit_timer - reinitialize interval timer after a clock step.
160  */
161 void
162 reinit_timer(void)
163 {
164 #if !defined(SYS_WINNT) && !defined(VMS)
165 	ZERO(itimer);
166 # ifdef HAVE_TIMER_CREATE
167 	timer_gettime(timer_id, &itimer);
168 # else
169 	getitimer(ITIMER_REAL, &itimer);
170 # endif
171 	if (itimer.it_value.tv_sec < 0 ||
172 	    itimer.it_value.tv_sec > (1 << EVENT_TIMEOUT))
173 		itimer.it_value.tv_sec = (1 << EVENT_TIMEOUT);
174 	if (itimer.it_value.itv_frac < 0)
175 		itimer.it_value.itv_frac = 0;
176 	if (0 == itimer.it_value.tv_sec &&
177 	    0 == itimer.it_value.itv_frac)
178 		itimer.it_value.tv_sec = (1 << EVENT_TIMEOUT);
179 	itimer.it_interval.tv_sec = (1 << EVENT_TIMEOUT);
180 	itimer.it_interval.itv_frac = 0;
181 	set_timer_or_die(&itimer);
182 # endif /* VMS */
183 }
184 
185 
186 /*
187  * init_timer - initialize the timer data structures
188  */
189 void
190 init_timer(void)
191 {
192 	/*
193 	 * Initialize...
194 	 */
195 	alarm_flag = FALSE;
196 	alarm_overflow = 0;
197 	adjust_timer = 1;
198 	stats_timer = SECSPERHR;
199 	leapf_timer = SECSPERDAY;
200 	huffpuff_timer = 0;
201 	interface_timer = 0;
202 	current_time = 0;
203 	timer_overflows = 0;
204 	timer_xmtcalls = 0;
205 	timer_timereset = 0;
206 
207 #ifndef SYS_WINNT
208 	/*
209 	 * Set up the alarm interrupt.	The first comes 2**EVENT_TIMEOUT
210 	 * seconds from now and they continue on every 2**EVENT_TIMEOUT
211 	 * seconds.
212 	 */
213 # ifndef VMS
214 #  ifdef HAVE_TIMER_CREATE
215 	if (TC_ERR == timer_create(CLOCK_REALTIME, NULL, &timer_id)) {
216 		msyslog(LOG_ERR, "timer_create failed, %m");
217 		exit(1);
218 	}
219 #  endif
220 	signal_no_reset(SIGALRM, alarming);
221 	itimer.it_interval.tv_sec =
222 		itimer.it_value.tv_sec = (1 << EVENT_TIMEOUT);
223 	itimer.it_interval.itv_frac = itimer.it_value.itv_frac = 0;
224 	set_timer_or_die(&itimer);
225 # else	/* VMS follows */
226 	vmsinc[0] = 10000000;		/* 1 sec */
227 	vmsinc[1] = 0;
228 	lib$emul(&(1<<EVENT_TIMEOUT), &vmsinc, &0, &vmsinc);
229 
230 	sys$gettim(&vmstimer);	/* that's "now" as abstime */
231 
232 	lib$addx(&vmsinc, &vmstimer, &vmstimer);
233 	sys$setimr(0, &vmstimer, alarming, alarming, 0);
234 # endif	/* VMS */
235 #else	/* SYS_WINNT follows */
236 	/*
237 	 * Set up timer interrupts for every 2**EVENT_TIMEOUT seconds
238 	 * Under Windows/NT,
239 	 */
240 
241 	WaitableTimerHandle = CreateWaitableTimer(NULL, FALSE, NULL);
242 	if (WaitableTimerHandle == NULL) {
243 		msyslog(LOG_ERR, "CreateWaitableTimer failed: %m");
244 		exit(1);
245 	}
246 	else {
247 		DWORD		Period;
248 		LARGE_INTEGER	DueTime;
249 		BOOL		rc;
250 
251 		Period = (1 << EVENT_TIMEOUT) * 1000;
252 		DueTime.QuadPart = Period * 10000i64;
253 		rc = SetWaitableTimer(WaitableTimerHandle, &DueTime,
254 				      Period, NULL, NULL, FALSE);
255 		if (!rc) {
256 			msyslog(LOG_ERR, "SetWaitableTimer failed: %m");
257 			exit(1);
258 		}
259 	}
260 
261 #endif	/* SYS_WINNT */
262 }
263 
264 
265 /*
266  * intres_timeout_req(s) is invoked in the parent to schedule an idle
267  * timeout to fire in s seconds, if not reset earlier by a call to
268  * intres_timeout_req(0), which clears any pending timeout.  When the
269  * timeout expires, worker_idle_timer_fired() is invoked (again, in the
270  * parent).
271  *
272  * sntp and ntpd each provide implementations adapted to their timers.
273  */
274 void
275 intres_timeout_req(
276 	u_int	seconds		/* 0 cancels */
277 	)
278 {
279 #if defined(HAVE_DROPROOT) && defined(NEED_EARLY_FORK)
280 	if (droproot) {
281 		worker_idle_timer = 0;
282 		return;
283 	}
284 #endif
285 	if (0 == seconds) {
286 		worker_idle_timer = 0;
287 		return;
288 	}
289 	worker_idle_timer = current_time + seconds;
290 }
291 
292 
293 /*
294  * timer - event timer
295  */
296 void
297 timer(void)
298 {
299 	struct peer *	p;
300 	struct peer *	next_peer;
301 	l_fp		now;
302 	time_t          tnow;
303 
304 	/*
305 	 * The basic timerevent is one second.  This is used to adjust the
306 	 * system clock in time and frequency, implement the kiss-o'-death
307 	 * function and the association polling function.
308 	 */
309 	current_time++;
310 	if (adjust_timer <= current_time) {
311 		adjust_timer += 1;
312 		adj_host_clock();
313 #ifdef REFCLOCK
314 		for (p = peer_list; p != NULL; p = next_peer) {
315 			next_peer = p->p_link;
316 			if (FLAG_REFCLOCK & p->flags)
317 				refclock_timer(p);
318 		}
319 #endif /* REFCLOCK */
320 	}
321 
322 	/*
323 	 * Now dispatch any peers whose event timer has expired. Be
324 	 * careful here, since the peer structure might go away as the
325 	 * result of the call.
326 	 */
327 	for (p = peer_list; p != NULL; p = next_peer) {
328 		next_peer = p->p_link;
329 
330 		/*
331 		 * Restrain the non-burst packet rate not more
332 		 * than one packet every 16 seconds. This is
333 		 * usually tripped using iburst and minpoll of
334 		 * 128 s or less.
335 		 */
336 		if (p->throttle > 0)
337 			p->throttle--;
338 		if (p->nextdate <= current_time) {
339 #ifdef REFCLOCK
340 			if (FLAG_REFCLOCK & p->flags)
341 				refclock_transmit(p);
342 			else
343 #endif	/* REFCLOCK */
344 				transmit(p);
345 		}
346 	}
347 
348 	/*
349 	 * Orphan mode is active when enabled and when no servers less
350 	 * than the orphan stratum are available. A server with no other
351 	 * synchronization source is an orphan. It shows offset zero and
352 	 * reference ID the loopback address.
353 	 *
354 	 * [bug 3644] If the orphan stratum is >= STRATUM_UNSPEC, we
355 	 * have to do it a bit different. 'clock_select()' simply
356 	 * tiptoed home, but since we're unsync'd and have no peer, we
357 	 * should eventually declare we're out of sync. Otherwise we
358 	 * would persistently claim we're good, and we're everything but
359 	 * that...
360 	 *
361 	 * XXX: do we want to log an event about this?
362 	 */
363 	if (sys_peer == NULL && current_time > orphwait) {
364 		if (sys_orphan < STRATUM_UNSPEC) {
365 			if (sys_leap == LEAP_NOTINSYNC) {
366 				set_sys_leap(LEAP_NOWARNING);
367 #ifdef AUTOKEY
368 				if (crypto_flags)
369 					crypto_update();
370 #endif	/* AUTOKEY */
371 			}
372 			sys_stratum = (u_char)sys_orphan;
373 		} else {
374 			if (sys_leap != LEAP_NOTINSYNC) {
375 				set_sys_leap(LEAP_NOTINSYNC);
376 				msyslog(LOG_WARNING, "%s",
377 					"no peer for too long, server running free now");
378 			}
379 			sys_stratum = STRATUM_UNSPEC;
380 		}
381 		if (sys_stratum > 1)
382 		    sys_refid = htonl(LOOPBACKADR);
383 		else
384 		    memcpy(&sys_refid, "LOOP", 4);
385 		sys_offset = 0;
386 		sys_rootdelay = 0;
387 		sys_rootdisp = 0;
388 	}
389 
390 	get_systime(&now);
391 	time(&tnow);
392 
393 	/*
394 	 * Leapseconds. Get time and defer to worker if either something
395 	 * is imminent or every 8th second.
396 	 */
397 	if (leapsec > LSPROX_NOWARN || 0 == (current_time & 7))
398 		check_leapsec(now.l_ui, &tnow,
399                                 (sys_leap == LEAP_NOTINSYNC));
400         if (sys_leap != LEAP_NOTINSYNC) {
401                 if (leapsec >= LSPROX_ANNOUNCE && leapdif) {
402 		        if (leapdif > 0)
403 			        set_sys_leap(LEAP_ADDSECOND);
404 		        else
405 			        set_sys_leap(LEAP_DELSECOND);
406                 } else {
407                         set_sys_leap(LEAP_NOWARNING);
408                 }
409 	}
410 
411 	/*
412 	 * Update huff-n'-puff filter.
413 	 */
414 	if (huffpuff_timer <= current_time) {
415 		huffpuff_timer += HUFFPUFF;
416 		huffpuff();
417 	}
418 
419 #ifdef AUTOKEY
420 	/*
421 	 * Garbage collect expired keys.
422 	 */
423 	if (keys_timer <= current_time) {
424 		keys_timer += (1UL << sys_automax);
425 		auth_agekeys();
426 	}
427 
428 	/*
429 	 * Generate new private value. This causes all associations
430 	 * to regenerate cookies.
431 	 */
432 	if (revoke_timer && revoke_timer <= current_time) {
433 		revoke_timer += (1UL << sys_revoke);
434 		RAND_bytes((u_char *)&sys_private, 4);
435 	}
436 #endif	/* AUTOKEY */
437 
438 	/*
439 	 * Interface update timer
440 	 */
441 	if (interface_interval && interface_timer <= current_time) {
442 		timer_interfacetimeout(current_time +
443 		    interface_interval);
444 		DPRINTF(2, ("timer: interface update\n"));
445 		interface_update(NULL, NULL);
446 	}
447 
448 	if (worker_idle_timer && worker_idle_timer <= current_time)
449 		worker_idle_timer_fired();
450 
451 	/*
452 	 * Finally, write hourly stats and do the hourly
453 	 * and daily leapfile checks.
454 	 */
455 	if (stats_timer <= current_time) {
456 		stats_timer += SECSPERHR;
457 		write_stats();
458 		if (leapf_timer <= current_time) {
459 			leapf_timer += SECSPERDAY;
460 			check_leap_file(TRUE, now.l_ui, &tnow);
461 		} else {
462 			check_leap_file(FALSE, now.l_ui, &tnow);
463 		}
464 	}
465 }
466 
467 
468 #ifndef SYS_WINNT
469 /*
470  * alarming - tell the world we've been alarmed
471  */
472 static RETSIGTYPE
473 alarming(
474 	int sig
475 	)
476 {
477 # ifdef DEBUG
478 	const char *msg = "alarming: initializing TRUE\n";
479 # endif
480 
481 	if (!initializing) {
482 		if (alarm_flag) {
483 			alarm_overflow++;
484 # ifdef DEBUG
485 			msg = "alarming: overflow\n";
486 # endif
487 		} else {
488 # ifndef VMS
489 			alarm_flag++;
490 # else
491 			/* VMS AST routine, increment is no good */
492 			alarm_flag = 1;
493 # endif
494 # ifdef DEBUG
495 			msg = "alarming: normal\n";
496 # endif
497 		}
498 	}
499 # ifdef VMS
500 	lib$addx(&vmsinc, &vmstimer, &vmstimer);
501 	sys$setimr(0, &vmstimer, alarming, alarming, 0);
502 # endif
503 # ifdef DEBUG
504 	if (debug >= 4)
505 		(void)(-1 == write(1, msg, strlen(msg)));
506 # endif
507 }
508 #endif /* SYS_WINNT */
509 
510 
511 void
512 timer_interfacetimeout(u_long timeout)
513 {
514 	interface_timer = timeout;
515 }
516 
517 
518 /*
519  * timer_clr_stats - clear timer module stat counters
520  */
521 void
522 timer_clr_stats(void)
523 {
524 	timer_overflows = 0;
525 	timer_xmtcalls = 0;
526 	timer_timereset = current_time;
527 }
528 
529 
530 static void
531 check_leap_sec_in_progress( const leap_result_t *lsdata ) {
532 	int prv_leap_sec_in_progress = leap_sec_in_progress;
533 	leap_sec_in_progress = lsdata->tai_diff && (lsdata->ddist < 3);
534 
535 	/* if changed we may have to update the leap status sent to clients */
536 	if (leap_sec_in_progress != prv_leap_sec_in_progress)
537 		set_sys_leap(sys_leap);
538 }
539 
540 
541 static void
542 check_leapsec(
543 	u_int32        now  ,
544 	const time_t * tpiv ,
545         int/*BOOL*/    reset)
546 {
547 	static const char leapmsg_p_step[] =
548 	    "Positive leap second, stepped backward.";
549 	static const char leapmsg_p_slew[] =
550 	    "Positive leap second, no step correction. "
551 	    "System clock will be inaccurate for a long time.";
552 
553 	static const char leapmsg_n_step[] =
554 	    "Negative leap second, stepped forward.";
555 	static const char leapmsg_n_slew[] =
556 	    "Negative leap second, no step correction. "
557 	    "System clock will be inaccurate for a long time.";
558 
559 	leap_result_t lsdata;
560 	u_int32       lsprox;
561 #ifdef AUTOKEY
562 	int/*BOOL*/   update_autokey = FALSE;
563 #endif
564 
565 #ifndef SYS_WINNT  /* WinNT port has its own leap second handling */
566 # ifdef KERNEL_PLL
567 	leapsec_electric(pll_control && kern_enable);
568 # else
569 	leapsec_electric(0);
570 # endif
571 #endif
572 #ifdef LEAP_SMEAR
573 	leap_smear.enabled = leap_smear_intv != 0;
574 #endif
575 	if (reset) {
576 		lsprox = LSPROX_NOWARN;
577 		leapsec_reset_frame();
578 		memset(&lsdata, 0, sizeof(lsdata));
579 	} else {
580 	  int fired;
581 
582 	  fired = leapsec_query(&lsdata, now, tpiv);
583 
584 	  DPRINTF(3, ("*** leapsec_query: fired %i, now %u (0x%08X), tai_diff %i, ddist %u\n",
585 		  fired, now, now, lsdata.tai_diff, lsdata.ddist));
586 
587 #ifdef LEAP_SMEAR
588 	  leap_smear.in_progress = 0;
589 	  leap_smear.doffset = 0.0;
590 
591 	  if (leap_smear.enabled) {
592 		if (lsdata.tai_diff) {
593 			if (leap_smear.interval == 0) {
594 				leap_smear.interval = leap_smear_intv;
595 				leap_smear.intv_end = lsdata.ttime.Q_s;
596 				leap_smear.intv_start = leap_smear.intv_end - leap_smear.interval;
597 				DPRINTF(1, ("*** leapsec_query: setting leap_smear interval %li, begin %.0f, end %.0f\n",
598 					leap_smear.interval, leap_smear.intv_start, leap_smear.intv_end));
599 			}
600 		} else {
601 			if (leap_smear.interval)
602 				DPRINTF(1, ("*** leapsec_query: clearing leap_smear interval\n"));
603 			leap_smear.interval = 0;
604 		}
605 
606 		if (leap_smear.interval) {
607 			double dtemp = now;
608 			if (dtemp >= leap_smear.intv_start && dtemp <= leap_smear.intv_end) {
609 				double leap_smear_time = dtemp - leap_smear.intv_start;
610 				/*
611 				 * For now we just do a linear interpolation over the smear interval
612 				 */
613 #if 0
614 				// linear interpolation
615 				leap_smear.doffset = -(leap_smear_time * lsdata.tai_diff / leap_smear.interval);
616 #else
617 				// Google approach: lie(t) = (1.0 - cos(pi * t / w)) / 2.0
618 				leap_smear.doffset = -((double) lsdata.tai_diff - cos( M_PI * leap_smear_time / leap_smear.interval)) / 2.0;
619 #endif
620 				/*
621 				 * TODO see if we're inside an inserted leap second, so we need to compute
622 				 * leap_smear.doffset = 1.0 - leap_smear.doffset
623 				 */
624 				leap_smear.in_progress = 1;
625 #if 0 && defined( DEBUG )
626 				msyslog(LOG_NOTICE, "*** leapsec_query: [%.0f:%.0f] (%li), now %u (%.0f), smear offset %.6f ms\n",
627 					leap_smear.intv_start, leap_smear.intv_end, leap_smear.interval,
628 					now, leap_smear_time, leap_smear.doffset);
629 #else
630 				DPRINTF(1, ("*** leapsec_query: [%.0f:%.0f] (%li), now %u (%.0f), smear offset %.6f ms\n",
631 					leap_smear.intv_start, leap_smear.intv_end, leap_smear.interval,
632 					now, leap_smear_time, leap_smear.doffset));
633 #endif
634 
635 			}
636 		}
637 	  }
638 	  else
639 		leap_smear.interval = 0;
640 
641 	  /*
642 	   * Update the current leap smear offset, eventually 0.0 if outside smear interval.
643 	   */
644 	  DTOLFP(leap_smear.doffset, &leap_smear.offset);
645 
646 #endif	/* LEAP_SMEAR */
647 
648 	  if (fired) {
649 		/* Full hit. Eventually step the clock, but always
650 		 * announce the leap event has happened.
651 		 */
652 		const char *leapmsg = NULL;
653 		double      lswarp  = lsdata.warped;
654 		if (lswarp < 0.0) {
655 			if (clock_max_back > 0.0 &&
656 			    clock_max_back < -lswarp) {
657 				step_systime(lswarp);
658 				leapmsg = leapmsg_p_step;
659 			} else {
660 				leapmsg = leapmsg_p_slew;
661 			}
662 		} else 	if (lswarp > 0.0) {
663 			if (clock_max_fwd > 0.0 &&
664 			    clock_max_fwd < lswarp) {
665 				step_systime(lswarp);
666 				leapmsg = leapmsg_n_step;
667 			} else {
668 				leapmsg = leapmsg_n_slew;
669 			}
670 		}
671 		if (leapmsg)
672 			msyslog(LOG_NOTICE, "%s", leapmsg);
673 		report_event(EVNT_LEAP, NULL, NULL);
674 #ifdef AUTOKEY
675 		update_autokey = TRUE;
676 #endif
677 		lsprox  = LSPROX_NOWARN;
678 		leapsec = LSPROX_NOWARN;
679 		sys_tai = lsdata.tai_offs;
680 	  } else {
681 #ifdef AUTOKEY
682 		  update_autokey = (sys_tai != (u_int)lsdata.tai_offs);
683 #endif
684 		  lsprox  = lsdata.proximity;
685 		  sys_tai = lsdata.tai_offs;
686 	  }
687 	}
688 
689 	/* We guard against panic alarming during the red alert phase.
690 	 * Strange and evil things might happen if we go from stone cold
691 	 * to piping hot in one step. If things are already that wobbly,
692 	 * we let the normal clock correction take over, even if a jump
693 	 * is involved.
694          * Also make sure the alarming events are edge-triggered, that is,
695          * ceated only when the threshold is crossed.
696          */
697 	if (  (leapsec > 0 || lsprox < LSPROX_ALERT)
698 	    && leapsec < lsprox                     ) {
699 		if (  leapsec < LSPROX_SCHEDULE
700                    && lsprox >= LSPROX_SCHEDULE) {
701 			if (lsdata.dynamic)
702 				report_event(PEVNT_ARMED, sys_peer, NULL);
703 			else
704 				report_event(EVNT_ARMED, NULL, NULL);
705 		}
706 		leapsec = lsprox;
707 	}
708 	if (leapsec > lsprox) {
709 		if (  leapsec >= LSPROX_SCHEDULE
710                    && lsprox   < LSPROX_SCHEDULE) {
711 			report_event(EVNT_DISARMED, NULL, NULL);
712 		}
713 		leapsec = lsprox;
714 	}
715 
716 	if (leapsec >= LSPROX_SCHEDULE)
717 		leapdif = lsdata.tai_diff;
718 	else
719 		leapdif = 0;
720 
721 	check_leap_sec_in_progress(&lsdata);
722 
723 #ifdef AUTOKEY
724 	if (update_autokey)
725 		crypto_update_taichange();
726 #endif
727 }
728