1/*
2 * Copyright (c) 2000-2007 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
78#include <sys/mount_internal.h>
79#include <sys/sysproto.h>
80#include <sys/signalvar.h>
81
82#include <kern/clock.h>
83#include <kern/task.h>
84#include <kern/thread_call.h>
85#if CONFIG_MACF
86#include <security/mac_framework.h>
87#endif
88
89#define HZ	100	/* XXX */
90
91/* simple lock used to access timezone, tz structure */
92lck_spin_t * tz_slock;
93lck_grp_t * tz_slock_grp;
94lck_attr_t * tz_slock_attr;
95lck_grp_attr_t	*tz_slock_grp_attr;
96
97static void		setthetime(
98					struct timeval	*tv);
99
100void time_zone_slock_init(void) __attribute__((section("__TEXT, initcode")));
101
102/*
103 * Time of day and interval timer support.
104 *
105 * These routines provide the kernel entry points to get and set
106 * the time-of-day and per-process interval timers.  Subroutines
107 * here provide support for adding and subtracting timeval structures
108 * and decrementing interval timers, optionally reloading the interval
109 * timers when they expire.
110 */
111/* ARGSUSED */
112int
113gettimeofday(
114__unused	struct proc	*p,
115			struct gettimeofday_args *uap,
116			register_t *retval)
117{
118	int error = 0;
119	struct timezone ltz; /* local copy */
120
121	if (uap->tp)
122		clock_gettimeofday((uint32_t *)&retval[0], (uint32_t *)&retval[1]);
123
124	if (uap->tzp) {
125		lck_spin_lock(tz_slock);
126		ltz = tz;
127		lck_spin_unlock(tz_slock);
128
129		error = copyout((caddr_t)&ltz, CAST_USER_ADDR_T(uap->tzp), sizeof (tz));
130	}
131
132	return (error);
133}
134
135/*
136 * XXX Y2038 bug because of setthetime() argument
137 */
138/* ARGSUSED */
139int
140settimeofday(__unused struct proc *p, struct settimeofday_args  *uap, __unused register_t *retval)
141{
142	struct timeval atv;
143	struct timezone atz;
144	int error;
145
146#if CONFIG_MACF
147	error = mac_system_check_settime(kauth_cred_get());
148	if (error)
149		return (error);
150#endif
151#ifndef CONFIG_EMBEDDED
152	if ((error = suser(kauth_cred_get(), &p->p_acflag)))
153		return (error);
154#endif
155	/* Verify all parameters before changing time */
156	if (uap->tv) {
157		if (IS_64BIT_PROCESS(p)) {
158			struct user_timeval user_atv;
159			error = copyin(uap->tv, &user_atv, sizeof(struct user_timeval));
160			atv.tv_sec = user_atv.tv_sec;
161			atv.tv_usec = user_atv.tv_usec;
162		} else {
163			error = copyin(uap->tv, &atv, sizeof(struct timeval));
164		}
165		if (error)
166			return (error);
167	}
168	if (uap->tzp && (error = copyin(uap->tzp, (caddr_t)&atz, sizeof(atz))))
169		return (error);
170	if (uap->tv) {
171		timevalfix(&atv);
172		if (atv.tv_sec < 0 || (atv.tv_sec == 0 && atv.tv_usec < 0))
173			return (EPERM);
174		setthetime(&atv);
175	}
176	if (uap->tzp) {
177		lck_spin_lock(tz_slock);
178		tz = atz;
179		lck_spin_unlock(tz_slock);
180	}
181	return (0);
182}
183
184static void
185setthetime(
186	struct timeval	*tv)
187{
188	clock_set_calendar_microtime(tv->tv_sec, tv->tv_usec);
189}
190
191/*
192 * XXX Y2038 bug because of clock_adjtime() first argument
193 */
194/* ARGSUSED */
195int
196adjtime(struct proc *p, struct adjtime_args *uap, __unused register_t *retval)
197{
198	struct timeval atv;
199	int error;
200
201#if CONFIG_MACF
202	error = mac_system_check_settime(kauth_cred_get());
203	if (error)
204		return (error);
205#endif
206	if ((error = suser(kauth_cred_get(), &p->p_acflag)))
207		return (error);
208	if (IS_64BIT_PROCESS(p)) {
209		struct user_timeval user_atv;
210		error = copyin(uap->delta, &user_atv, sizeof(struct user_timeval));
211		atv.tv_sec = user_atv.tv_sec;
212		atv.tv_usec = user_atv.tv_usec;
213	} else {
214		error = copyin(uap->delta, &atv, sizeof(struct timeval));
215	}
216	if (error)
217		return (error);
218
219	/*
220	 * Compute the total correction and the rate at which to apply it.
221	 */
222	clock_adjtime((int32_t *)&atv.tv_sec, &atv.tv_usec);
223
224	if (uap->olddelta) {
225		if (IS_64BIT_PROCESS(p)) {
226			struct user_timeval user_atv;
227			user_atv.tv_sec = atv.tv_sec;
228			user_atv.tv_usec = atv.tv_usec;
229			error = copyout(&user_atv, uap->olddelta, sizeof(struct user_timeval));
230		} else {
231			error = copyout(&atv, uap->olddelta, sizeof(struct timeval));
232		}
233	}
234
235	return (0);
236}
237
238/*
239 *	Verify the calendar value.  If negative,
240 *	reset to zero (the epoch).
241 */
242void
243inittodr(
244	__unused time_t	base)
245{
246	struct timeval	tv;
247
248	/*
249	 * Assertion:
250	 * The calendar has already been
251	 * set up from the platform clock.
252	 *
253	 * The value returned by microtime()
254	 * is gotten from the calendar.
255	 */
256	microtime(&tv);
257
258	if (tv.tv_sec < 0 || tv.tv_usec < 0) {
259		printf ("WARNING: preposterous time in Real Time Clock");
260		tv.tv_sec = 0;		/* the UNIX epoch */
261		tv.tv_usec = 0;
262		setthetime(&tv);
263		printf(" -- CHECK AND RESET THE DATE!\n");
264	}
265}
266
267time_t
268boottime_sec(void)
269{
270	uint32_t	sec, nanosec;
271	clock_get_boottime_nanotime(&sec, &nanosec);
272	return (sec);
273}
274
275uint64_t tvtoabstime(struct timeval *tvp);
276
277/*
278 * Get value of an interval timer.  The process virtual and
279 * profiling virtual time timers are kept internally in the
280 * way they are specified externally: in time until they expire.
281 *
282 * The real time interval timer expiration time (p_rtime)
283 * is kept as an absolute time rather than as a delta, so that
284 * it is easy to keep periodic real-time signals from drifting.
285 *
286 * The real time timer is processed by a callout routine.
287 * Since a callout may be delayed in real time due to
288 * other processing in the system, it is possible for the real
289 * time callout routine (realitexpire, given below), to be delayed
290 * in real time past when it is supposed to occur.  It does not
291 * suffice, therefore, to reload the real time .it_value from the
292 * real time .it_interval.  Rather, we compute the next time in
293 * absolute time when the timer should go off.
294 *
295 * Returns:	0			Success
296 *		EINVAL			Invalid argument
297 *	copyout:EFAULT			Bad address
298 */
299/* ARGSUSED */
300int
301getitimer(struct proc *p, struct getitimer_args *uap, __unused register_t *retval)
302{
303	struct itimerval aitv;
304
305	if (uap->which > ITIMER_PROF)
306		return(EINVAL);
307
308	proc_spinlock(p);
309	switch (uap->which) {
310
311	case ITIMER_REAL:
312		/*
313		 * If time for real time timer has passed return 0,
314		 * else return difference between current time and
315		 * time for the timer to go off.
316		 */
317		aitv = p->p_realtimer;
318		if (timerisset(&p->p_rtime)) {
319			struct timeval		now;
320
321			microuptime(&now);
322			if (timercmp(&p->p_rtime, &now, <))
323				timerclear(&aitv.it_value);
324			else {
325				aitv.it_value = p->p_rtime;
326				timevalsub(&aitv.it_value, &now);
327			}
328		}
329		else
330			timerclear(&aitv.it_value);
331		break;
332
333	case ITIMER_VIRTUAL:
334		aitv = p->p_vtimer_user;
335		break;
336
337	case ITIMER_PROF:
338		aitv = p->p_vtimer_prof;
339		break;
340	}
341
342	proc_spinunlock(p);
343
344	if (IS_64BIT_PROCESS(p)) {
345		struct user_itimerval user_itv;
346		user_itv.it_interval.tv_sec = aitv.it_interval.tv_sec;
347		user_itv.it_interval.tv_usec = aitv.it_interval.tv_usec;
348		user_itv.it_value.tv_sec = aitv.it_value.tv_sec;
349		user_itv.it_value.tv_usec = aitv.it_value.tv_usec;
350		return (copyout((caddr_t)&user_itv, uap->itv, sizeof (struct user_itimerval)));
351	} else {
352		return (copyout((caddr_t)&aitv, uap->itv, sizeof (struct itimerval)));
353	}
354}
355
356/*
357 * Returns:	0			Success
358 *		EINVAL			Invalid argument
359 *	copyin:EFAULT			Bad address
360 *	getitimer:EINVAL		Invalid argument
361 *	getitimer:EFAULT		Bad address
362 */
363/* ARGSUSED */
364int
365setitimer(struct proc *p, struct setitimer_args *uap, register_t *retval)
366{
367	struct itimerval aitv;
368	user_addr_t itvp;
369	int error;
370
371	if (uap->which > ITIMER_PROF)
372		return (EINVAL);
373	if ((itvp = uap->itv)) {
374		if (IS_64BIT_PROCESS(p)) {
375			struct user_itimerval user_itv;
376			if ((error = copyin(itvp, (caddr_t)&user_itv, sizeof (struct user_itimerval))))
377				return (error);
378			aitv.it_interval.tv_sec = user_itv.it_interval.tv_sec;
379			aitv.it_interval.tv_usec = user_itv.it_interval.tv_usec;
380			aitv.it_value.tv_sec = user_itv.it_value.tv_sec;
381			aitv.it_value.tv_usec = user_itv.it_value.tv_usec;
382		} else {
383			if ((error = copyin(itvp, (caddr_t)&aitv, sizeof (struct itimerval))))
384				return (error);
385		}
386	}
387	if ((uap->itv = uap->oitv) && (error = getitimer(p, (struct getitimer_args *)uap, retval)))
388		return (error);
389	if (itvp == 0)
390		return (0);
391	if (itimerfix(&aitv.it_value) || itimerfix(&aitv.it_interval))
392		return (EINVAL);
393
394	switch (uap->which) {
395
396	case ITIMER_REAL:
397		proc_spinlock(p);
398		if (timerisset(&aitv.it_value)) {
399			microuptime(&p->p_rtime);
400			timevaladd(&p->p_rtime, &aitv.it_value);
401			p->p_realtimer = aitv;
402			if (!thread_call_enter_delayed(p->p_rcall, tvtoabstime(&p->p_rtime)))
403				p->p_ractive++;
404		} else  {
405			timerclear(&p->p_rtime);
406			p->p_realtimer = aitv;
407			if (thread_call_cancel(p->p_rcall))
408				p->p_ractive--;
409		}
410		proc_spinunlock(p);
411
412		break;
413
414
415	case ITIMER_VIRTUAL:
416		if (timerisset(&aitv.it_value))
417			task_vtimer_set(p->task, TASK_VTIMER_USER);
418	else
419			task_vtimer_clear(p->task, TASK_VTIMER_USER);
420
421		proc_spinlock(p);
422		p->p_vtimer_user = aitv;
423		proc_spinunlock(p);
424		break;
425
426	case ITIMER_PROF:
427		if (timerisset(&aitv.it_value))
428			task_vtimer_set(p->task, TASK_VTIMER_PROF);
429		else
430			task_vtimer_clear(p->task, TASK_VTIMER_PROF);
431
432		proc_spinlock(p);
433		p->p_vtimer_prof = aitv;
434		proc_spinunlock(p);
435		break;
436	}
437
438	return (0);
439}
440
441/*
442 * Real interval timer expired:
443 * send process whose timer expired an alarm signal.
444 * If time is not set up to reload, then just return.
445 * Else compute next time timer should go off which is > current time.
446 * This is where delay in processing this timeout causes multiple
447 * SIGALRM calls to be compressed into one.
448 */
449void
450realitexpire(
451	struct proc	*p)
452{
453	struct proc *r;
454	struct timeval	t;
455
456	r = proc_find(p->p_pid);
457
458	proc_spinlock(p);
459
460	if (--p->p_ractive > 0 || r != p) {
461		proc_spinunlock(p);
462
463		if (r != NULL)
464			proc_rele(r);
465		return;
466	}
467
468	if (!timerisset(&p->p_realtimer.it_interval)) {
469		timerclear(&p->p_rtime);
470		proc_spinunlock(p);
471
472		psignal(p, SIGALRM);
473		proc_rele(p);
474		return;
475	}
476
477	microuptime(&t);
478	timevaladd(&p->p_rtime, &p->p_realtimer.it_interval);
479	if (timercmp(&p->p_rtime, &t, <=)) {
480		if ((p->p_rtime.tv_sec + 2) >= t.tv_sec) {
481			for (;;) {
482				timevaladd(&p->p_rtime, &p->p_realtimer.it_interval);
483				if (timercmp(&p->p_rtime, &t, >))
484					break;
485			}
486		}
487		else {
488			p->p_rtime = p->p_realtimer.it_interval;
489			timevaladd(&p->p_rtime, &t);
490		}
491	}
492
493	if (!thread_call_enter_delayed(p->p_rcall, tvtoabstime(&p->p_rtime)))
494		p->p_ractive++;
495	proc_spinunlock(p);
496
497	psignal(p, SIGALRM);
498	proc_rele(p);
499}
500
501/*
502 * Check that a proposed value to load into the .it_value or
503 * .it_interval part of an interval timer is acceptable.
504 */
505int
506itimerfix(
507	struct timeval *tv)
508{
509
510	if (tv->tv_sec < 0 || tv->tv_sec > 100000000 ||
511	    tv->tv_usec < 0 || tv->tv_usec >= 1000000)
512		return (EINVAL);
513	return (0);
514}
515
516/*
517 * Decrement an interval timer by a specified number
518 * of microseconds, which must be less than a second,
519 * i.e. < 1000000.  If the timer expires, then reload
520 * it.  In this case, carry over (usec - old value) to
521 * reduce the value reloaded into the timer so that
522 * the timer does not drift.  This routine assumes
523 * that it is called in a context where the timers
524 * on which it is operating cannot change in value.
525 */
526int
527itimerdecr(proc_t p,
528	struct itimerval *itp, int usec)
529{
530
531	proc_spinlock(p);
532
533	if (itp->it_value.tv_usec < usec) {
534		if (itp->it_value.tv_sec == 0) {
535			/* expired, and already in next interval */
536			usec -= itp->it_value.tv_usec;
537			goto expire;
538		}
539		itp->it_value.tv_usec += 1000000;
540		itp->it_value.tv_sec--;
541	}
542	itp->it_value.tv_usec -= usec;
543	usec = 0;
544	if (timerisset(&itp->it_value)) {
545		proc_spinunlock(p);
546		return (1);
547	}
548	/* expired, exactly at end of interval */
549expire:
550	if (timerisset(&itp->it_interval)) {
551		itp->it_value = itp->it_interval;
552		if (itp->it_value.tv_sec > 0) {
553		itp->it_value.tv_usec -= usec;
554		if (itp->it_value.tv_usec < 0) {
555			itp->it_value.tv_usec += 1000000;
556			itp->it_value.tv_sec--;
557			}
558		}
559	} else
560		itp->it_value.tv_usec = 0;		/* sec is already 0 */
561	proc_spinunlock(p);
562	return (0);
563}
564
565/*
566 * Add and subtract routines for timevals.
567 * N.B.: subtract routine doesn't deal with
568 * results which are before the beginning,
569 * it just gets very confused in this case.
570 * Caveat emptor.
571 */
572void
573timevaladd(
574	struct timeval *t1,
575	struct timeval *t2)
576{
577
578	t1->tv_sec += t2->tv_sec;
579	t1->tv_usec += t2->tv_usec;
580	timevalfix(t1);
581}
582void
583timevalsub(
584	struct timeval *t1,
585	struct timeval *t2)
586{
587
588	t1->tv_sec -= t2->tv_sec;
589	t1->tv_usec -= t2->tv_usec;
590	timevalfix(t1);
591}
592void
593timevalfix(
594	struct timeval *t1)
595{
596
597	if (t1->tv_usec < 0) {
598		t1->tv_sec--;
599		t1->tv_usec += 1000000;
600	}
601	if (t1->tv_usec >= 1000000) {
602		t1->tv_sec++;
603		t1->tv_usec -= 1000000;
604	}
605}
606
607/*
608 * Return the best possible estimate of the time in the timeval
609 * to which tvp points.
610 */
611void
612microtime(
613	struct timeval	*tvp)
614{
615	clock_get_calendar_microtime((uint32_t *)&tvp->tv_sec, (uint32_t *)&tvp->tv_usec);
616}
617
618void
619microuptime(
620	struct timeval	*tvp)
621{
622	clock_get_system_microtime((uint32_t *)&tvp->tv_sec, (uint32_t *)&tvp->tv_usec);
623}
624
625/*
626 * Ditto for timespec.
627 */
628void
629nanotime(
630	struct timespec *tsp)
631{
632	clock_get_calendar_nanotime((uint32_t *)&tsp->tv_sec, (uint32_t *)&tsp->tv_nsec);
633}
634
635void
636nanouptime(
637	struct timespec *tsp)
638{
639	clock_get_system_nanotime((uint32_t *)&tsp->tv_sec, (uint32_t *)&tsp->tv_nsec);
640}
641
642uint64_t
643tvtoabstime(
644	struct timeval	*tvp)
645{
646	uint64_t	result, usresult;
647
648	clock_interval_to_absolutetime_interval(
649						tvp->tv_sec, NSEC_PER_SEC, &result);
650	clock_interval_to_absolutetime_interval(
651						tvp->tv_usec, NSEC_PER_USEC, &usresult);
652
653	return (result + usresult);
654}
655void
656time_zone_slock_init(void)
657{
658	/* allocate lock group attribute and group */
659	tz_slock_grp_attr = lck_grp_attr_alloc_init();
660
661	tz_slock_grp =  lck_grp_alloc_init("tzlock", tz_slock_grp_attr);
662
663	/* Allocate lock attribute */
664	tz_slock_attr = lck_attr_alloc_init();
665
666	/* Allocate the spin lock */
667	tz_slock = lck_spin_alloc_init(tz_slock_grp, tz_slock_attr);
668}
669