1/*
2 * Copyright (c) 2000-2008 Apple Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28/* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
29/*
30 * Copyright (c) 1982, 1986, 1989, 1993
31 *	The Regents of the University of California.  All rights reserved.
32 *
33 * Redistribution and use in source and binary forms, with or without
34 * modification, are permitted provided that the following conditions
35 * are met:
36 * 1. Redistributions of source code must retain the above copyright
37 *    notice, this list of conditions and the following disclaimer.
38 * 2. Redistributions in binary form must reproduce the above copyright
39 *    notice, this list of conditions and the following disclaimer in the
40 *    documentation and/or other materials provided with the distribution.
41 * 3. All advertising materials mentioning features or use of this software
42 *    must display the following acknowledgement:
43 *	This product includes software developed by the University of
44 *	California, Berkeley and its contributors.
45 * 4. Neither the name of the University nor the names of its contributors
46 *    may be used to endorse or promote products derived from this software
47 *    without specific prior written permission.
48 *
49 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
50 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
51 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
52 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
53 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
54 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
55 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
56 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
57 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
58 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
59 * SUCH DAMAGE.
60 *
61 *	@(#)kern_time.c	8.4 (Berkeley) 5/26/95
62 */
63/*
64 * NOTICE: This file was modified by SPARTA, Inc. in 2005 to introduce
65 * support for mandatory and extensible security protections.  This notice
66 * is included in support of clause 2.2 (b) of the Apple Public License,
67 * Version 2.0.
68 */
69
70#include <sys/param.h>
71#include <sys/resourcevar.h>
72#include <sys/kernel.h>
73#include <sys/systm.h>
74#include <sys/proc_internal.h>
75#include <sys/kauth.h>
76#include <sys/vnode.h>
77#include <sys/time.h>
78#include <sys/priv.h>
79
80#include <sys/mount_internal.h>
81#include <sys/sysproto.h>
82#include <sys/signalvar.h>
83#include <sys/protosw.h> /* for net_uptime2timeval() */
84
85#include <kern/clock.h>
86#include <kern/task.h>
87#include <kern/thread_call.h>
88#if CONFIG_MACF
89#include <security/mac_framework.h>
90#endif
91
92#define HZ	100	/* XXX */
93
94/* simple lock used to access timezone, tz structure */
95lck_spin_t * tz_slock;
96lck_grp_t * tz_slock_grp;
97lck_attr_t * tz_slock_attr;
98lck_grp_attr_t	*tz_slock_grp_attr;
99
100static void		setthetime(
101					struct timeval	*tv);
102
103void time_zone_slock_init(void);
104
105/*
106 * Time of day and interval timer support.
107 *
108 * These routines provide the kernel entry points to get and set
109 * the time-of-day and per-process interval timers.  Subroutines
110 * here provide support for adding and subtracting timeval structures
111 * and decrementing interval timers, optionally reloading the interval
112 * timers when they expire.
113 */
114/* ARGSUSED */
115int
116gettimeofday(
117__unused	struct proc	*p,
118			struct gettimeofday_args *uap,
119			int32_t *retval)
120{
121	int error = 0;
122	struct timezone ltz; /* local copy */
123
124	if (uap->tp) {
125		clock_sec_t		secs;
126		clock_usec_t	usecs;
127
128		clock_gettimeofday(&secs, &usecs);
129		retval[0] = secs;
130		retval[1] = usecs;
131	}
132
133	if (uap->tzp) {
134		lck_spin_lock(tz_slock);
135		ltz = tz;
136		lck_spin_unlock(tz_slock);
137
138		error = copyout((caddr_t)&ltz, CAST_USER_ADDR_T(uap->tzp), sizeof (tz));
139	}
140
141	return (error);
142}
143
144/*
145 * XXX Y2038 bug because of setthetime() argument
146 */
147/* ARGSUSED */
148int
149settimeofday(__unused struct proc *p, struct settimeofday_args  *uap, __unused int32_t *retval)
150{
151	struct timeval atv;
152	struct timezone atz;
153	int error;
154
155	bzero(&atv, sizeof(atv));
156
157#if CONFIG_MACF
158	error = mac_system_check_settime(kauth_cred_get());
159	if (error)
160		return (error);
161#endif
162	if ((error = suser(kauth_cred_get(), &p->p_acflag)))
163		return (error);
164	/* Verify all parameters before changing time */
165	if (uap->tv) {
166		if (IS_64BIT_PROCESS(p)) {
167			struct user64_timeval user_atv;
168			error = copyin(uap->tv, &user_atv, sizeof(user_atv));
169			atv.tv_sec = user_atv.tv_sec;
170			atv.tv_usec = user_atv.tv_usec;
171		} else {
172			struct user32_timeval user_atv;
173			error = copyin(uap->tv, &user_atv, sizeof(user_atv));
174			atv.tv_sec = user_atv.tv_sec;
175			atv.tv_usec = user_atv.tv_usec;
176		}
177		if (error)
178			return (error);
179	}
180	if (uap->tzp && (error = copyin(uap->tzp, (caddr_t)&atz, sizeof(atz))))
181		return (error);
182	if (uap->tv) {
183		timevalfix(&atv);
184		if (atv.tv_sec < 0 || (atv.tv_sec == 0 && atv.tv_usec < 0))
185			return (EPERM);
186		setthetime(&atv);
187	}
188	if (uap->tzp) {
189		lck_spin_lock(tz_slock);
190		tz = atz;
191		lck_spin_unlock(tz_slock);
192	}
193	return (0);
194}
195
196static void
197setthetime(
198	struct timeval	*tv)
199{
200	clock_set_calendar_microtime(tv->tv_sec, tv->tv_usec);
201}
202
203/*
204 * XXX Y2038 bug because of clock_adjtime() first argument
205 */
206/* ARGSUSED */
207int
208adjtime(struct proc *p, struct adjtime_args *uap, __unused int32_t *retval)
209{
210	struct timeval atv;
211	int error;
212
213#if CONFIG_MACF
214	error = mac_system_check_settime(kauth_cred_get());
215	if (error)
216		return (error);
217#endif
218	if ((error = priv_check_cred(kauth_cred_get(), PRIV_ADJTIME, 0)))
219		return (error);
220	if (IS_64BIT_PROCESS(p)) {
221		struct user64_timeval user_atv;
222		error = copyin(uap->delta, &user_atv, sizeof(user_atv));
223		atv.tv_sec = user_atv.tv_sec;
224		atv.tv_usec = user_atv.tv_usec;
225	} else {
226		struct user32_timeval user_atv;
227		error = copyin(uap->delta, &user_atv, sizeof(user_atv));
228		atv.tv_sec = user_atv.tv_sec;
229		atv.tv_usec = user_atv.tv_usec;
230	}
231	if (error)
232		return (error);
233
234	/*
235	 * Compute the total correction and the rate at which to apply it.
236	 */
237	clock_adjtime(&atv.tv_sec, &atv.tv_usec);
238
239	if (uap->olddelta) {
240		if (IS_64BIT_PROCESS(p)) {
241			struct user64_timeval user_atv;
242			user_atv.tv_sec = atv.tv_sec;
243			user_atv.tv_usec = atv.tv_usec;
244			error = copyout(&user_atv, uap->olddelta, sizeof(user_atv));
245		} else {
246			struct user32_timeval user_atv;
247			user_atv.tv_sec = atv.tv_sec;
248			user_atv.tv_usec = atv.tv_usec;
249			error = copyout(&user_atv, uap->olddelta, sizeof(user_atv));
250		}
251	}
252
253	return (0);
254}
255
256/*
257 *	Verify the calendar value.  If negative,
258 *	reset to zero (the epoch).
259 */
260void
261inittodr(
262	__unused time_t	base)
263{
264	struct timeval	tv;
265
266	/*
267	 * Assertion:
268	 * The calendar has already been
269	 * set up from the platform clock.
270	 *
271	 * The value returned by microtime()
272	 * is gotten from the calendar.
273	 */
274	microtime(&tv);
275
276	if (tv.tv_sec < 0 || tv.tv_usec < 0) {
277		printf ("WARNING: preposterous time in Real Time Clock");
278		tv.tv_sec = 0;		/* the UNIX epoch */
279		tv.tv_usec = 0;
280		setthetime(&tv);
281		printf(" -- CHECK AND RESET THE DATE!\n");
282	}
283}
284
285time_t
286boottime_sec(void)
287{
288	clock_sec_t		secs;
289	clock_nsec_t	nanosecs;
290
291	clock_get_boottime_nanotime(&secs, &nanosecs);
292	return (secs);
293}
294
295/*
296 * Get value of an interval timer.  The process virtual and
297 * profiling virtual time timers are kept internally in the
298 * way they are specified externally: in time until they expire.
299 *
300 * The real time interval timer expiration time (p_rtime)
301 * is kept as an absolute time rather than as a delta, so that
302 * it is easy to keep periodic real-time signals from drifting.
303 *
304 * The real time timer is processed by a callout routine.
305 * Since a callout may be delayed in real time due to
306 * other processing in the system, it is possible for the real
307 * time callout routine (realitexpire, given below), to be delayed
308 * in real time past when it is supposed to occur.  It does not
309 * suffice, therefore, to reload the real time .it_value from the
310 * real time .it_interval.  Rather, we compute the next time in
311 * absolute time when the timer should go off.
312 *
313 * Returns:	0			Success
314 *		EINVAL			Invalid argument
315 *	copyout:EFAULT			Bad address
316 */
317/* ARGSUSED */
318int
319getitimer(struct proc *p, struct getitimer_args *uap, __unused int32_t *retval)
320{
321	struct itimerval aitv;
322
323	if (uap->which > ITIMER_PROF)
324		return(EINVAL);
325
326	bzero(&aitv, sizeof(aitv));
327
328	proc_spinlock(p);
329	switch (uap->which) {
330
331	case ITIMER_REAL:
332		/*
333		 * If time for real time timer has passed return 0,
334		 * else return difference between current time and
335		 * time for the timer to go off.
336		 */
337		aitv = p->p_realtimer;
338		if (timerisset(&p->p_rtime)) {
339			struct timeval		now;
340
341			microuptime(&now);
342			if (timercmp(&p->p_rtime, &now, <))
343				timerclear(&aitv.it_value);
344			else {
345				aitv.it_value = p->p_rtime;
346				timevalsub(&aitv.it_value, &now);
347			}
348		}
349		else
350			timerclear(&aitv.it_value);
351		break;
352
353	case ITIMER_VIRTUAL:
354		aitv = p->p_vtimer_user;
355		break;
356
357	case ITIMER_PROF:
358		aitv = p->p_vtimer_prof;
359		break;
360	}
361
362	proc_spinunlock(p);
363
364	if (IS_64BIT_PROCESS(p)) {
365		struct user64_itimerval user_itv;
366		user_itv.it_interval.tv_sec = aitv.it_interval.tv_sec;
367		user_itv.it_interval.tv_usec = aitv.it_interval.tv_usec;
368		user_itv.it_value.tv_sec = aitv.it_value.tv_sec;
369		user_itv.it_value.tv_usec = aitv.it_value.tv_usec;
370		return (copyout((caddr_t)&user_itv, uap->itv, sizeof (user_itv)));
371	} else {
372		struct user32_itimerval user_itv;
373		user_itv.it_interval.tv_sec = aitv.it_interval.tv_sec;
374		user_itv.it_interval.tv_usec = aitv.it_interval.tv_usec;
375		user_itv.it_value.tv_sec = aitv.it_value.tv_sec;
376		user_itv.it_value.tv_usec = aitv.it_value.tv_usec;
377		return (copyout((caddr_t)&user_itv, uap->itv, sizeof (user_itv)));
378	}
379}
380
381/*
382 * Returns:	0			Success
383 *		EINVAL			Invalid argument
384 *	copyin:EFAULT			Bad address
385 *	getitimer:EINVAL		Invalid argument
386 *	getitimer:EFAULT		Bad address
387 */
388/* ARGSUSED */
389int
390setitimer(struct proc *p, struct setitimer_args *uap, int32_t *retval)
391{
392	struct itimerval aitv;
393	user_addr_t itvp;
394	int error;
395
396	bzero(&aitv, sizeof(aitv));
397
398	if (uap->which > ITIMER_PROF)
399		return (EINVAL);
400	if ((itvp = uap->itv)) {
401		if (IS_64BIT_PROCESS(p)) {
402			struct user64_itimerval user_itv;
403			if ((error = copyin(itvp, (caddr_t)&user_itv, sizeof (user_itv))))
404				return (error);
405			aitv.it_interval.tv_sec = user_itv.it_interval.tv_sec;
406			aitv.it_interval.tv_usec = user_itv.it_interval.tv_usec;
407			aitv.it_value.tv_sec = user_itv.it_value.tv_sec;
408			aitv.it_value.tv_usec = user_itv.it_value.tv_usec;
409		} else {
410			struct user32_itimerval user_itv;
411			if ((error = copyin(itvp, (caddr_t)&user_itv, sizeof (user_itv))))
412				return (error);
413			aitv.it_interval.tv_sec = user_itv.it_interval.tv_sec;
414			aitv.it_interval.tv_usec = user_itv.it_interval.tv_usec;
415			aitv.it_value.tv_sec = user_itv.it_value.tv_sec;
416			aitv.it_value.tv_usec = user_itv.it_value.tv_usec;
417		}
418	}
419	if ((uap->itv = uap->oitv) && (error = getitimer(p, (struct getitimer_args *)uap, retval)))
420		return (error);
421	if (itvp == 0)
422		return (0);
423	if (itimerfix(&aitv.it_value) || itimerfix(&aitv.it_interval))
424		return (EINVAL);
425
426	switch (uap->which) {
427
428	case ITIMER_REAL:
429		proc_spinlock(p);
430		if (timerisset(&aitv.it_value)) {
431			microuptime(&p->p_rtime);
432			timevaladd(&p->p_rtime, &aitv.it_value);
433			p->p_realtimer = aitv;
434			if (!thread_call_enter_delayed_with_leeway(p->p_rcall, NULL,
435					         tvtoabstime(&p->p_rtime), 0, THREAD_CALL_DELAY_USER_NORMAL))
436				p->p_ractive++;
437		} else  {
438			timerclear(&p->p_rtime);
439			p->p_realtimer = aitv;
440			if (thread_call_cancel(p->p_rcall))
441				p->p_ractive--;
442		}
443		proc_spinunlock(p);
444
445		break;
446
447
448	case ITIMER_VIRTUAL:
449		if (timerisset(&aitv.it_value))
450			task_vtimer_set(p->task, TASK_VTIMER_USER);
451	else
452			task_vtimer_clear(p->task, TASK_VTIMER_USER);
453
454		proc_spinlock(p);
455		p->p_vtimer_user = aitv;
456		proc_spinunlock(p);
457		break;
458
459	case ITIMER_PROF:
460		if (timerisset(&aitv.it_value))
461			task_vtimer_set(p->task, TASK_VTIMER_PROF);
462		else
463			task_vtimer_clear(p->task, TASK_VTIMER_PROF);
464
465		proc_spinlock(p);
466		p->p_vtimer_prof = aitv;
467		proc_spinunlock(p);
468		break;
469	}
470
471	return (0);
472}
473
474/*
475 * Real interval timer expired:
476 * send process whose timer expired an alarm signal.
477 * If time is not set up to reload, then just return.
478 * Else compute next time timer should go off which is > current time.
479 * This is where delay in processing this timeout causes multiple
480 * SIGALRM calls to be compressed into one.
481 */
482void
483realitexpire(
484	struct proc	*p)
485{
486	struct proc *r;
487	struct timeval	t;
488
489	r = proc_find(p->p_pid);
490
491	proc_spinlock(p);
492
493	if (--p->p_ractive > 0 || r != p) {
494		proc_spinunlock(p);
495
496		if (r != NULL)
497			proc_rele(r);
498		return;
499	}
500
501	if (!timerisset(&p->p_realtimer.it_interval)) {
502		timerclear(&p->p_rtime);
503		proc_spinunlock(p);
504
505		psignal(p, SIGALRM);
506		proc_rele(p);
507		return;
508	}
509
510	microuptime(&t);
511	timevaladd(&p->p_rtime, &p->p_realtimer.it_interval);
512	if (timercmp(&p->p_rtime, &t, <=)) {
513		if ((p->p_rtime.tv_sec + 2) >= t.tv_sec) {
514			for (;;) {
515				timevaladd(&p->p_rtime, &p->p_realtimer.it_interval);
516				if (timercmp(&p->p_rtime, &t, >))
517					break;
518			}
519		}
520		else {
521			p->p_rtime = p->p_realtimer.it_interval;
522			timevaladd(&p->p_rtime, &t);
523		}
524	}
525
526	if (!thread_call_enter_delayed(p->p_rcall, tvtoabstime(&p->p_rtime)))
527		p->p_ractive++;
528	proc_spinunlock(p);
529
530	psignal(p, SIGALRM);
531	proc_rele(p);
532}
533
534/*
535 * Check that a proposed value to load into the .it_value or
536 * .it_interval part of an interval timer is acceptable.
537 */
538int
539itimerfix(
540	struct timeval *tv)
541{
542
543	if (tv->tv_sec < 0 || tv->tv_sec > 100000000 ||
544	    tv->tv_usec < 0 || tv->tv_usec >= 1000000)
545		return (EINVAL);
546	return (0);
547}
548
549/*
550 * Decrement an interval timer by a specified number
551 * of microseconds, which must be less than a second,
552 * i.e. < 1000000.  If the timer expires, then reload
553 * it.  In this case, carry over (usec - old value) to
554 * reduce the value reloaded into the timer so that
555 * the timer does not drift.  This routine assumes
556 * that it is called in a context where the timers
557 * on which it is operating cannot change in value.
558 */
559int
560itimerdecr(proc_t p,
561	struct itimerval *itp, int usec)
562{
563
564	proc_spinlock(p);
565
566	if (itp->it_value.tv_usec < usec) {
567		if (itp->it_value.tv_sec == 0) {
568			/* expired, and already in next interval */
569			usec -= itp->it_value.tv_usec;
570			goto expire;
571		}
572		itp->it_value.tv_usec += 1000000;
573		itp->it_value.tv_sec--;
574	}
575	itp->it_value.tv_usec -= usec;
576	usec = 0;
577	if (timerisset(&itp->it_value)) {
578		proc_spinunlock(p);
579		return (1);
580	}
581	/* expired, exactly at end of interval */
582expire:
583	if (timerisset(&itp->it_interval)) {
584		itp->it_value = itp->it_interval;
585		if (itp->it_value.tv_sec > 0) {
586		itp->it_value.tv_usec -= usec;
587		if (itp->it_value.tv_usec < 0) {
588			itp->it_value.tv_usec += 1000000;
589			itp->it_value.tv_sec--;
590			}
591		}
592	} else
593		itp->it_value.tv_usec = 0;		/* sec is already 0 */
594	proc_spinunlock(p);
595	return (0);
596}
597
598/*
599 * Add and subtract routines for timevals.
600 * N.B.: subtract routine doesn't deal with
601 * results which are before the beginning,
602 * it just gets very confused in this case.
603 * Caveat emptor.
604 */
605void
606timevaladd(
607	struct timeval *t1,
608	struct timeval *t2)
609{
610
611	t1->tv_sec += t2->tv_sec;
612	t1->tv_usec += t2->tv_usec;
613	timevalfix(t1);
614}
615void
616timevalsub(
617	struct timeval *t1,
618	struct timeval *t2)
619{
620
621	t1->tv_sec -= t2->tv_sec;
622	t1->tv_usec -= t2->tv_usec;
623	timevalfix(t1);
624}
625void
626timevalfix(
627	struct timeval *t1)
628{
629
630	if (t1->tv_usec < 0) {
631		t1->tv_sec--;
632		t1->tv_usec += 1000000;
633	}
634	if (t1->tv_usec >= 1000000) {
635		t1->tv_sec++;
636		t1->tv_usec -= 1000000;
637	}
638}
639
640/*
641 * Return the best possible estimate of the time in the timeval
642 * to which tvp points.
643 */
644void
645microtime(
646	struct timeval	*tvp)
647{
648	clock_sec_t		tv_sec;
649	clock_usec_t	tv_usec;
650
651	clock_get_calendar_microtime(&tv_sec, &tv_usec);
652
653	tvp->tv_sec = tv_sec;
654	tvp->tv_usec = tv_usec;
655}
656
657void
658microtime_with_abstime(
659	struct timeval	*tvp, uint64_t *abstime)
660{
661	clock_sec_t		tv_sec;
662	clock_usec_t	tv_usec;
663
664	clock_get_calendar_absolute_and_microtime(&tv_sec, &tv_usec, abstime);
665
666	tvp->tv_sec = tv_sec;
667	tvp->tv_usec = tv_usec;
668}
669
670void
671microuptime(
672	struct timeval	*tvp)
673{
674	clock_sec_t		tv_sec;
675	clock_usec_t	tv_usec;
676
677	clock_get_system_microtime(&tv_sec, &tv_usec);
678
679	tvp->tv_sec = tv_sec;
680	tvp->tv_usec = tv_usec;
681}
682
683/*
684 * Ditto for timespec.
685 */
686void
687nanotime(
688	struct timespec *tsp)
689{
690	clock_sec_t		tv_sec;
691	clock_nsec_t	tv_nsec;
692
693	clock_get_calendar_nanotime(&tv_sec, &tv_nsec);
694
695	tsp->tv_sec = tv_sec;
696	tsp->tv_nsec = tv_nsec;
697}
698
699void
700nanouptime(
701	struct timespec *tsp)
702{
703	clock_sec_t		tv_sec;
704	clock_nsec_t	tv_nsec;
705
706	clock_get_system_nanotime(&tv_sec, &tv_nsec);
707
708	tsp->tv_sec = tv_sec;
709	tsp->tv_nsec = tv_nsec;
710}
711
712uint64_t
713tvtoabstime(
714	struct timeval	*tvp)
715{
716	uint64_t	result, usresult;
717
718	clock_interval_to_absolutetime_interval(
719						tvp->tv_sec, NSEC_PER_SEC, &result);
720	clock_interval_to_absolutetime_interval(
721						tvp->tv_usec, NSEC_PER_USEC, &usresult);
722
723	return (result + usresult);
724}
725
726#if NETWORKING
727/*
728 * ratecheck(): simple time-based rate-limit checking.
729 */
730int
731ratecheck(struct timeval *lasttime, const struct timeval *mininterval)
732{
733	struct timeval tv, delta;
734	int rv = 0;
735
736	net_uptime2timeval(&tv);
737	delta = tv;
738	timevalsub(&delta, lasttime);
739
740	/*
741	 * check for 0,0 is so that the message will be seen at least once,
742	 * even if interval is huge.
743	 */
744	if (timevalcmp(&delta, mininterval, >=) ||
745	    (lasttime->tv_sec == 0 && lasttime->tv_usec == 0)) {
746		*lasttime = tv;
747		rv = 1;
748	}
749
750	return (rv);
751}
752
753/*
754 * ppsratecheck(): packets (or events) per second limitation.
755 */
756int
757ppsratecheck(struct timeval *lasttime, int *curpps, int maxpps)
758{
759	struct timeval tv, delta;
760	int rv;
761
762	net_uptime2timeval(&tv);
763
764	timersub(&tv, lasttime, &delta);
765
766	/*
767	 * Check for 0,0 so that the message will be seen at least once.
768	 * If more than one second has passed since the last update of
769	 * lasttime, reset the counter.
770	 *
771	 * we do increment *curpps even in *curpps < maxpps case, as some may
772	 * try to use *curpps for stat purposes as well.
773	 */
774	if ((lasttime->tv_sec == 0 && lasttime->tv_usec == 0) ||
775	    delta.tv_sec >= 1) {
776		*lasttime = tv;
777		*curpps = 0;
778		rv = 1;
779	} else if (maxpps < 0)
780		rv = 1;
781	else if (*curpps < maxpps)
782		rv = 1;
783	else
784		rv = 0;
785
786#if 1 /* DIAGNOSTIC? */
787	/* be careful about wrap-around */
788	if (*curpps + 1 > 0)
789		*curpps = *curpps + 1;
790#else
791	/*
792	 * assume that there's not too many calls to this function.
793	 * not sure if the assumption holds, as it depends on *caller's*
794	 * behavior, not the behavior of this function.
795	 * IMHO it is wrong to make assumption on the caller's behavior,
796	 * so the above #if is #if 1, not #ifdef DIAGNOSTIC.
797	 */
798	*curpps = *curpps + 1;
799#endif
800
801	return (rv);
802}
803#endif /* NETWORKING */
804
805void
806time_zone_slock_init(void)
807{
808	/* allocate lock group attribute and group */
809	tz_slock_grp_attr = lck_grp_attr_alloc_init();
810
811	tz_slock_grp =  lck_grp_alloc_init("tzlock", tz_slock_grp_attr);
812
813	/* Allocate lock attribute */
814	tz_slock_attr = lck_attr_alloc_init();
815
816	/* Allocate the spin lock */
817	tz_slock = lck_spin_alloc_init(tz_slock_grp, tz_slock_attr);
818}
819