bsd/kern/kern_time.c

   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 */
  95 lck_spin_t * tz_slock;
  96 lck_grp_t * tz_slock_grp;
  97 lck_attr_t * tz_slock_attr;
  98 lck_grp_attr_t  *tz_slock_grp_attr;
  99
 100 static void             setthetime(
 101                                         struct timeval  *tv);
 102
 103 void 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 */
 115 int
 116 gettimeofday(
 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 */
 148 int
 149 settimeofday(__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
 196 static void
 197 setthetime(
 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 */
 207 int
 208 adjtime(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  */
 260 void
 261 inittodr(
 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
 285 time_t
 286 boottime_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 */
 318 int
 319 getitimer(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 */
 389 int
 390 setitimer(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  */
 482 void
 483 realitexpire(
 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  */
 538 int
 539 itimerfix(
 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 int
 550 timespec_is_valid(const struct timespec *ts)
 551 {
 552         /* The INT32_MAX limit ensures the timespec is safe for clock_*() functions
 553          * which accept 32-bit ints. */
 554         if (ts->tv_sec < 0 || ts->tv_sec > INT32_MAX ||
 555                         ts->tv_nsec < 0 || (unsigned long long)ts->tv_nsec > NSEC_PER_SEC) {
 556                 return 0;
 557         }
 558         return 1;
 559 }
 560
 561 /*
 562  * Decrement an interval timer by a specified number
 563  * of microseconds, which must be less than a second,
 564  * i.e. < 1000000.  If the timer expires, then reload
 565  * it.  In this case, carry over (usec - old value) to
 566  * reduce the value reloaded into the timer so that
 567  * the timer does not drift.  This routine assumes
 568  * that it is called in a context where the timers
 569  * on which it is operating cannot change in value.
 570  */
 571 int
 572 itimerdecr(proc_t p,
 573         struct itimerval *itp, int usec)
 574 {
 575
 576         proc_spinlock(p);
 577
 578         if (itp->it_value.tv_usec < usec) {
 579                 if (itp->it_value.tv_sec == 0) {
 580                         /* expired, and already in next interval */
 581                         usec -= itp->it_value.tv_usec;
 582                         goto expire;
 583                 }
 584                 itp->it_value.tv_usec += 1000000;
 585                 itp->it_value.tv_sec--;
 586         }
 587         itp->it_value.tv_usec -= usec;
 588         usec = 0;
 589         if (timerisset(&itp->it_value)) {
 590                 proc_spinunlock(p);
 591                 return (1);
 592         }
 593         /* expired, exactly at end of interval */
 594 expire:
 595         if (timerisset(&itp->it_interval)) {
 596                 itp->it_value = itp->it_interval;
 597                 if (itp->it_value.tv_sec > 0) {
 598                 itp->it_value.tv_usec -= usec;
 599                 if (itp->it_value.tv_usec < 0) {
 600                         itp->it_value.tv_usec += 1000000;
 601                         itp->it_value.tv_sec--;
 602                         }
 603                 }
 604         } else
 605                 itp->it_value.tv_usec = 0;              /* sec is already 0 */
 606         proc_spinunlock(p);
 607         return (0);
 608 }
 609
 610 /*
 611  * Add and subtract routines for timevals.
 612  * N.B.: subtract routine doesn't deal with
 613  * results which are before the beginning,
 614  * it just gets very confused in this case.
 615  * Caveat emptor.
 616  */
 617 void
 618 timevaladd(
 619         struct timeval *t1,
 620         struct timeval *t2)
 621 {
 622
 623         t1->tv_sec += t2->tv_sec;
 624         t1->tv_usec += t2->tv_usec;
 625         timevalfix(t1);
 626 }
 627 void
 628 timevalsub(
 629         struct timeval *t1,
 630         struct timeval *t2)
 631 {
 632
 633         t1->tv_sec -= t2->tv_sec;
 634         t1->tv_usec -= t2->tv_usec;
 635         timevalfix(t1);
 636 }
 637 void
 638 timevalfix(
 639         struct timeval *t1)
 640 {
 641
 642         if (t1->tv_usec < 0) {
 643                 t1->tv_sec--;
 644                 t1->tv_usec += 1000000;
 645         }
 646         if (t1->tv_usec >= 1000000) {
 647                 t1->tv_sec++;
 648                 t1->tv_usec -= 1000000;
 649         }
 650 }
 651
 652 /*
 653  * Return the best possible estimate of the time in the timeval
 654  * to which tvp points.
 655  */
 656 void
 657 microtime(
 658         struct timeval  *tvp)
 659 {
 660         clock_sec_t             tv_sec;
 661         clock_usec_t    tv_usec;
 662
 663         clock_get_calendar_microtime(&tv_sec, &tv_usec);
 664
 665         tvp->tv_sec = tv_sec;
 666         tvp->tv_usec = tv_usec;
 667 }
 668
 669 void
 670 microtime_with_abstime(
 671         struct timeval  *tvp, uint64_t *abstime)
 672 {
 673         clock_sec_t             tv_sec;
 674         clock_usec_t    tv_usec;
 675
 676         clock_get_calendar_absolute_and_microtime(&tv_sec, &tv_usec, abstime);
 677
 678         tvp->tv_sec = tv_sec;
 679         tvp->tv_usec = tv_usec;
 680 }
 681
 682 void
 683 microuptime(
 684         struct timeval  *tvp)
 685 {
 686         clock_sec_t             tv_sec;
 687         clock_usec_t    tv_usec;
 688
 689         clock_get_system_microtime(&tv_sec, &tv_usec);
 690
 691         tvp->tv_sec = tv_sec;
 692         tvp->tv_usec = tv_usec;
 693 }
 694
 695 /*
 696  * Ditto for timespec.
 697  */
 698 void
 699 nanotime(
 700         struct timespec *tsp)
 701 {
 702         clock_sec_t             tv_sec;
 703         clock_nsec_t    tv_nsec;
 704
 705         clock_get_calendar_nanotime(&tv_sec, &tv_nsec);
 706
 707         tsp->tv_sec = tv_sec;
 708         tsp->tv_nsec = tv_nsec;
 709 }
 710
 711 void
 712 nanouptime(
 713         struct timespec *tsp)
 714 {
 715         clock_sec_t             tv_sec;
 716         clock_nsec_t    tv_nsec;
 717
 718         clock_get_system_nanotime(&tv_sec, &tv_nsec);
 719
 720         tsp->tv_sec = tv_sec;
 721         tsp->tv_nsec = tv_nsec;
 722 }
 723
 724 uint64_t
 725 tvtoabstime(
 726         struct timeval  *tvp)
 727 {
 728         uint64_t        result, usresult;
 729
 730         clock_interval_to_absolutetime_interval(
 731                                                 tvp->tv_sec, NSEC_PER_SEC, &result);
 732         clock_interval_to_absolutetime_interval(
 733                                                 tvp->tv_usec, NSEC_PER_USEC, &usresult);
 734
 735         return (result + usresult);
 736 }
 737
 738 uint64_t
 739 tstoabstime(struct timespec *ts)
 740 {
 741         uint64_t abstime_s, abstime_ns;
 742         clock_interval_to_absolutetime_interval(ts->tv_sec, NSEC_PER_SEC, &abstime_s);
 743         clock_interval_to_absolutetime_interval(ts->tv_nsec, 1, &abstime_ns);
 744         return abstime_s + abstime_ns;
 745 }
 746
 747 #if NETWORKING
 748 /*
 749  * ratecheck(): simple time-based rate-limit checking.
 750  */
 751 int
 752 ratecheck(struct timeval *lasttime, const struct timeval *mininterval)
 753 {
 754         struct timeval tv, delta;
 755         int rv = 0;
 756
 757         net_uptime2timeval(&tv);
 758         delta = tv;
 759         timevalsub(&delta, lasttime);
 760
 761         /*
 762          * check for 0,0 is so that the message will be seen at least once,
 763          * even if interval is huge.
 764          */
 765         if (timevalcmp(&delta, mininterval, >=) ||
 766             (lasttime->tv_sec == 0 && lasttime->tv_usec == 0)) {
 767                 *lasttime = tv;
 768                 rv = 1;
 769         }
 770
 771         return (rv);
 772 }
 773
 774 /*
 775  * ppsratecheck(): packets (or events) per second limitation.
 776  */
 777 int
 778 ppsratecheck(struct timeval *lasttime, int *curpps, int maxpps)
 779 {
 780         struct timeval tv, delta;
 781         int rv;
 782
 783         net_uptime2timeval(&tv);
 784
 785         timersub(&tv, lasttime, &delta);
 786
 787         /*
 788          * Check for 0,0 so that the message will be seen at least once.
 789          * If more than one second has passed since the last update of
 790          * lasttime, reset the counter.
 791          *
 792          * we do increment *curpps even in *curpps < maxpps case, as some may
 793          * try to use *curpps for stat purposes as well.
 794          */
 795         if ((lasttime->tv_sec == 0 && lasttime->tv_usec == 0) ||
 796             delta.tv_sec >= 1) {
 797                 *lasttime = tv;
 798                 *curpps = 0;
 799                 rv = 1;
 800         } else if (maxpps < 0)
 801                 rv = 1;
 802         else if (*curpps < maxpps)
 803                 rv = 1;
 804         else
 805                 rv = 0;
 806
 807 #if 1 /* DIAGNOSTIC? */
 808         /* be careful about wrap-around */
 809         if (*curpps + 1 > 0)
 810                 *curpps = *curpps + 1;
 811 #else
 812         /*
 813          * assume that there's not too many calls to this function.
 814          * not sure if the assumption holds, as it depends on *caller's*
 815          * behavior, not the behavior of this function.
 816          * IMHO it is wrong to make assumption on the caller's behavior,
 817          * so the above #if is #if 1, not #ifdef DIAGNOSTIC.
 818          */
 819         *curpps = *curpps + 1;
 820 #endif
 821
 822         return (rv);
 823 }
 824 #endif /* NETWORKING */
 825
 826 void
 827 time_zone_slock_init(void)
 828 {
 829         /* allocate lock group attribute and group */
 830         tz_slock_grp_attr = lck_grp_attr_alloc_init();
 831
 832         tz_slock_grp =  lck_grp_alloc_init("tzlock", tz_slock_grp_attr);
 833
 834         /* Allocate lock attribute */
 835         tz_slock_attr = lck_attr_alloc_init();
 836
 837         /* Allocate the spin lock */
 838         tz_slock = lck_spin_alloc_init(tz_slock_grp, tz_slock_attr);
 839 }