2 * ntp_timer.c - event timer support routines
8 #include "ntp_machine.h"
10 #include "ntp_stdlib.h"
11 #include "ntp_calendar.h"
12 #include "ntp_leapsec.h"
14 #if defined(HAVE_IO_COMPLETION_PORT)
15 # include "ntp_iocompletionport.h"
16 # include "ntp_timer.h"
21 #ifdef HAVE_SYS_SIGNAL_H
22 # include <sys/signal.h>
29 #include "ntp_syscall.h"
30 #endif /* KERNEL_PLL */
33 #include <openssl/rand.h>
37 /* TC_ERR represents the timer_create() error return value. */
45 static void check_leapsec(u_int32, const time_t*, int/*BOOL*/);
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
57 volatile int interface_interval; /* init_io() sets def. 300s */
60 * Initializing flag. All async routines watch this and only do their
61 * thing when it is clear.
66 * Alarm flag. The mainline code imports this.
68 volatile int alarm_flag;
71 * The counters and timeouts
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 */
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) */
90 * Statistics counter for the interested.
92 volatile u_long alarm_overflow;
94 u_long current_time; /* seconds since startup */
97 * Stats. Number of overflows and number of calls to transmit().
99 u_long timer_timereset;
100 u_long timer_overflows;
101 u_long timer_xmtcalls;
104 static int vmstimer[2]; /* time for next timer AST */
105 static int vmsinc[2]; /* timer increment */
109 HANDLE WaitableTimerHandle;
111 static RETSIGTYPE alarming (int);
112 #endif /* SYS_WINNT */
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
121 typedef struct itimerval intervaltimer;
122 # define itv_frac tv_usec
124 intervaltimer itimer;
128 #if !defined(SYS_WINNT) && !defined(VMS)
129 void set_timer_or_die(const intervaltimer *);
133 #if !defined(SYS_WINNT) && !defined(VMS)
136 const intervaltimer * ptimer
139 const char * setfunc;
142 # ifdef HAVE_TIMER_CREATE
143 setfunc = "timer_settime";
144 rc = timer_settime(timer_id, 0, &itimer, NULL);
146 setfunc = "setitimer";
147 rc = setitimer(ITIMER_REAL, &itimer, NULL);
150 msyslog(LOG_ERR, "interval timer %s failed, %m",
155 #endif /* !SYS_WINNT && !VMS */
159 * reinit_timer - reinitialize interval timer after a clock step.
164 #if !defined(SYS_WINNT) && !defined(VMS)
166 # ifdef HAVE_TIMER_CREATE
167 timer_gettime(timer_id, &itimer);
169 getitimer(ITIMER_REAL, &itimer);
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);
187 * init_timer - initialize the timer data structures
198 stats_timer = SECSPERHR;
199 leapf_timer = SECSPERDAY;
209 * Set up the alarm interrupt. The first comes 2**EVENT_TIMEOUT
210 * seconds from now and they continue on every 2**EVENT_TIMEOUT
214 # ifdef HAVE_TIMER_CREATE
215 if (TC_ERR == timer_create(CLOCK_REALTIME, NULL, &timer_id)) {
216 msyslog(LOG_ERR, "timer_create failed, %m");
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 */
228 lib$emul(&(1<<EVENT_TIMEOUT), &vmsinc, &0, &vmsinc);
230 sys$gettim(&vmstimer); /* that's "now" as abstime */
232 lib$addx(&vmsinc, &vmstimer, &vmstimer);
233 sys$setimr(0, &vmstimer, alarming, alarming, 0);
235 #else /* SYS_WINNT follows */
237 * Set up timer interrupts for every 2**EVENT_TIMEOUT seconds
241 WaitableTimerHandle = CreateWaitableTimer(NULL, FALSE, NULL);
242 if (WaitableTimerHandle == NULL) {
243 msyslog(LOG_ERR, "CreateWaitableTimer failed: %m");
248 LARGE_INTEGER DueTime;
251 Period = (1 << EVENT_TIMEOUT) * 1000;
252 DueTime.QuadPart = Period * 10000i64;
253 rc = SetWaitableTimer(WaitableTimerHandle, &DueTime,
254 Period, NULL, NULL, FALSE);
256 msyslog(LOG_ERR, "SetWaitableTimer failed: %m");
261 #endif /* SYS_WINNT */
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
272 * sntp and ntpd each provide implementations adapted to their timers.
276 u_int seconds /* 0 cancels */
279 #if defined(HAVE_DROPROOT) && defined(NEED_EARLY_FORK)
281 worker_idle_timer = 0;
286 worker_idle_timer = 0;
289 worker_idle_timer = current_time + seconds;
294 * timer - event timer
300 struct peer * next_peer;
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.
310 if (adjust_timer <= current_time) {
314 for (p = peer_list; p != NULL; p = next_peer) {
315 next_peer = p->p_link;
316 if (FLAG_REFCLOCK & p->flags)
319 #endif /* REFCLOCK */
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.
327 for (p = peer_list; p != NULL; p = next_peer) {
328 next_peer = p->p_link;
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
338 if (p->nextdate <= current_time) {
340 if (FLAG_REFCLOCK & p->flags)
341 refclock_transmit(p);
343 #endif /* REFCLOCK */
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.
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
361 * XXX: do we want to log an event about this?
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);
372 sys_stratum = (u_char)sys_orphan;
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");
379 sys_stratum = STRATUM_UNSPEC;
382 sys_refid = htonl(LOOPBACKADR);
384 memcpy(&sys_refid, "LOOP", 4);
394 * Leapseconds. Get time and defer to worker if either something
395 * is imminent or every 8th second.
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) {
403 set_sys_leap(LEAP_ADDSECOND);
405 set_sys_leap(LEAP_DELSECOND);
407 set_sys_leap(LEAP_NOWARNING);
412 * Update huff-n'-puff filter.
414 if (huffpuff_timer <= current_time) {
415 huffpuff_timer += HUFFPUFF;
421 * Garbage collect expired keys.
423 if (keys_timer <= current_time) {
424 keys_timer += (1UL << sys_automax);
429 * Generate new private value. This causes all associations
430 * to regenerate cookies.
432 if (revoke_timer && revoke_timer <= current_time) {
433 revoke_timer += (1UL << sys_revoke);
434 RAND_bytes((u_char *)&sys_private, 4);
439 * Interface update timer
441 if (interface_interval && interface_timer <= current_time) {
442 timer_interfacetimeout(current_time +
444 DPRINTF(2, ("timer: interface update\n"));
445 interface_update(NULL, NULL);
448 if (worker_idle_timer && worker_idle_timer <= current_time)
449 worker_idle_timer_fired();
452 * Finally, write hourly stats and do the hourly
453 * and daily leapfile checks.
455 if (stats_timer <= current_time) {
456 stats_timer += SECSPERHR;
458 if (leapf_timer <= current_time) {
459 leapf_timer += SECSPERDAY;
460 check_leap_file(TRUE, now.l_ui, &tnow);
462 check_leap_file(FALSE, now.l_ui, &tnow);
470 * alarming - tell the world we've been alarmed
478 const char *msg = "alarming: initializing TRUE\n";
485 msg = "alarming: overflow\n";
491 /* VMS AST routine, increment is no good */
495 msg = "alarming: normal\n";
500 lib$addx(&vmsinc, &vmstimer, &vmstimer);
501 sys$setimr(0, &vmstimer, alarming, alarming, 0);
505 (void)(-1 == write(1, msg, strlen(msg)));
508 #endif /* SYS_WINNT */
512 timer_interfacetimeout(u_long timeout)
514 interface_timer = timeout;
519 * timer_clr_stats - clear timer module stat counters
522 timer_clr_stats(void)
526 timer_timereset = current_time;
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);
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);
544 const time_t * tpiv ,
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.";
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.";
559 leap_result_t lsdata;
562 int/*BOOL*/ update_autokey = FALSE;
565 #ifndef SYS_WINNT /* WinNT port has its own leap second handling */
567 leapsec_electric(pll_control && kern_enable);
573 leap_smear.enabled = leap_smear_intv != 0;
576 lsprox = LSPROX_NOWARN;
577 leapsec_reset_frame();
578 memset(&lsdata, 0, sizeof(lsdata));
582 fired = leapsec_query(&lsdata, now, tpiv);
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));
588 leap_smear.in_progress = 0;
589 leap_smear.doffset = 0.0;
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));
601 if (leap_smear.interval)
602 DPRINTF(1, ("*** leapsec_query: clearing leap_smear interval\n"));
603 leap_smear.interval = 0;
606 if (leap_smear.interval) {
608 if (dtemp >= leap_smear.intv_start && dtemp <= leap_smear.intv_end) {
609 double leap_smear_time = dtemp - leap_smear.intv_start;
611 * For now we just do a linear interpolation over the smear interval
614 // linear interpolation
615 leap_smear.doffset = -(leap_smear_time * lsdata.tai_diff / leap_smear.interval);
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;
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
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);
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));
639 leap_smear.interval = 0;
642 * Update the current leap smear offset, eventually 0.0 if outside smear interval.
644 DTOLFP(leap_smear.doffset, &leap_smear.offset);
646 #endif /* LEAP_SMEAR */
649 /* Full hit. Eventually step the clock, but always
650 * announce the leap event has happened.
652 const char *leapmsg = NULL;
653 double lswarp = lsdata.warped;
655 if (clock_max_back > 0.0 &&
656 clock_max_back < -lswarp) {
657 step_systime(lswarp);
658 leapmsg = leapmsg_p_step;
660 leapmsg = leapmsg_p_slew;
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;
668 leapmsg = leapmsg_n_slew;
672 msyslog(LOG_NOTICE, "%s", leapmsg);
673 report_event(EVNT_LEAP, NULL, NULL);
675 update_autokey = TRUE;
677 lsprox = LSPROX_NOWARN;
678 leapsec = LSPROX_NOWARN;
679 sys_tai = lsdata.tai_offs;
682 update_autokey = (sys_tai != (u_int)lsdata.tai_offs);
684 lsprox = lsdata.proximity;
685 sys_tai = lsdata.tai_offs;
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
694 * Also make sure the alarming events are edge-triggered, that is,
695 * ceated only when the threshold is crossed.
697 if ( (leapsec > 0 || lsprox < LSPROX_ALERT)
698 && leapsec < lsprox ) {
699 if ( leapsec < LSPROX_SCHEDULE
700 && lsprox >= LSPROX_SCHEDULE) {
702 report_event(PEVNT_ARMED, sys_peer, NULL);
704 report_event(EVNT_ARMED, NULL, NULL);
708 if (leapsec > lsprox) {
709 if ( leapsec >= LSPROX_SCHEDULE
710 && lsprox < LSPROX_SCHEDULE) {
711 report_event(EVNT_DISARMED, NULL, NULL);
716 if (leapsec >= LSPROX_SCHEDULE)
717 leapdif = lsdata.tai_diff;
721 check_leap_sec_in_progress(&lsdata);
725 crypto_update_taichange();