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 #include <IOKit/IOBSD.h>
  92 #include <sys/time.h>
  93
  94 #define HZ      100     /* XXX */
  95
  96 /* simple lock used to access timezone, tz structure */
  97 lck_spin_t * tz_slock;
  98 lck_grp_t * tz_slock_grp;
  99 lck_attr_t * tz_slock_attr;
 100 lck_grp_attr_t  *tz_slock_grp_attr;
 101
 102 static void             setthetime(
 103                                         struct timeval  *tv);
 104
 105 void time_zone_slock_init(void);
 106
 107 /*
 108  * Time of day and interval timer support.
 109  *
 110  * These routines provide the kernel entry points to get and set
 111  * the time-of-day and per-process interval timers.  Subroutines
 112  * here provide support for adding and subtracting timeval structures
 113  * and decrementing interval timers, optionally reloading the interval
 114  * timers when they expire.
 115  */
 116 /* ARGSUSED */
 117 int
 118 gettimeofday(
 119                         struct proc     *p,
 120                         struct gettimeofday_args *uap,
 121                         __unused int32_t *retval)
 122 {
 123         int error = 0;
 124         struct timezone ltz; /* local copy */
 125         clock_sec_t secs;
 126         clock_usec_t usecs;
 127         uint64_t mach_time;
 128
 129         if (uap->tp || uap->mach_absolute_time) {
 130                 clock_gettimeofday_and_absolute_time(&secs, &usecs, &mach_time);
 131         }
 132
 133         if (uap->tp) {
 134                 /* Casting secs through a uint32_t to match arm64 commpage */
 135                 if (IS_64BIT_PROCESS(p)) {
 136                         struct user64_timeval user_atv = {};
 137                         user_atv.tv_sec = (uint32_t)secs;
 138                         user_atv.tv_usec = usecs;
 139                         error = copyout(&user_atv, uap->tp, sizeof(user_atv));
 140                 } else {
 141                         struct user32_timeval user_atv = {};
 142                         user_atv.tv_sec = (uint32_t)secs;
 143                         user_atv.tv_usec = usecs;
 144                         error = copyout(&user_atv, uap->tp, sizeof(user_atv));
 145                 }
 146                 if (error) {
 147                         return error;
 148                 }
 149         }
 150
 151         if (uap->tzp) {
 152                 lck_spin_lock(tz_slock);
 153                 ltz = tz;
 154                 lck_spin_unlock(tz_slock);
 155
 156                 error = copyout((caddr_t)&ltz, CAST_USER_ADDR_T(uap->tzp), sizeof(tz));
 157         }
 158
 159         if (error == 0 && uap->mach_absolute_time) {
 160                 error = copyout(&mach_time, uap->mach_absolute_time, sizeof(mach_time));
 161         }
 162
 163         return error;
 164 }
 165
 166 /*
 167  * XXX Y2038 bug because of setthetime() argument
 168  */
 169 /* ARGSUSED */
 170 int
 171 settimeofday(__unused struct proc *p, struct settimeofday_args  *uap, __unused int32_t *retval)
 172 {
 173         struct timeval atv;
 174         struct timezone atz;
 175         int error;
 176
 177         bzero(&atv, sizeof(atv));
 178
 179         /* Check that this task is entitled to set the time or it is root */
 180         if (!IOTaskHasEntitlement(current_task(), SETTIME_ENTITLEMENT)) {
 181
 182 #if CONFIG_MACF
 183                 error = mac_system_check_settime(kauth_cred_get());
 184                 if (error)
 185                         return (error);
 186 #endif
 187 #ifndef CONFIG_EMBEDDED
 188                 if ((error = suser(kauth_cred_get(), &p->p_acflag)))
 189                         return (error);
 190 #endif
 191         }
 192
 193         /* Verify all parameters before changing time */
 194         if (uap->tv) {
 195                 if (IS_64BIT_PROCESS(p)) {
 196                         struct user64_timeval user_atv;
 197                         error = copyin(uap->tv, &user_atv, sizeof(user_atv));
 198                         atv.tv_sec = user_atv.tv_sec;
 199                         atv.tv_usec = user_atv.tv_usec;
 200                 } else {
 201                         struct user32_timeval user_atv;
 202                         error = copyin(uap->tv, &user_atv, sizeof(user_atv));
 203                         atv.tv_sec = user_atv.tv_sec;
 204                         atv.tv_usec = user_atv.tv_usec;
 205                 }
 206                 if (error)
 207                         return (error);
 208         }
 209         if (uap->tzp && (error = copyin(uap->tzp, (caddr_t)&atz, sizeof(atz))))
 210                 return (error);
 211         if (uap->tv) {
 212                 timevalfix(&atv);
 213                 if (atv.tv_sec < 0 || (atv.tv_sec == 0 && atv.tv_usec < 0))
 214                         return (EPERM);
 215                 setthetime(&atv);
 216         }
 217         if (uap->tzp) {
 218                 lck_spin_lock(tz_slock);
 219                 tz = atz;
 220                 lck_spin_unlock(tz_slock);
 221         }
 222         return (0);
 223 }
 224
 225 static void
 226 setthetime(
 227         struct timeval  *tv)
 228 {
 229         clock_set_calendar_microtime(tv->tv_sec, tv->tv_usec);
 230 }
 231
 232 /*
 233  *      Verify the calendar value.  If negative,
 234  *      reset to zero (the epoch).
 235  */
 236 void
 237 inittodr(
 238         __unused time_t base)
 239 {
 240         struct timeval  tv;
 241
 242         /*
 243          * Assertion:
 244          * The calendar has already been
 245          * set up from the platform clock.
 246          *
 247          * The value returned by microtime()
 248          * is gotten from the calendar.
 249          */
 250         microtime(&tv);
 251
 252         if (tv.tv_sec < 0 || tv.tv_usec < 0) {
 253                 printf ("WARNING: preposterous time in Real Time Clock");
 254                 tv.tv_sec = 0;          /* the UNIX epoch */
 255                 tv.tv_usec = 0;
 256                 setthetime(&tv);
 257                 printf(" -- CHECK AND RESET THE DATE!\n");
 258         }
 259 }
 260
 261 time_t
 262 boottime_sec(void)
 263 {
 264         clock_sec_t             secs;
 265         clock_nsec_t    nanosecs;
 266
 267         clock_get_boottime_nanotime(&secs, &nanosecs);
 268         return (secs);
 269 }
 270
 271 void
 272 boottime_timeval(struct timeval *tv)
 273 {
 274         clock_sec_t             secs;
 275         clock_usec_t    microsecs;
 276
 277         clock_get_boottime_microtime(&secs, &microsecs);
 278
 279         tv->tv_sec = secs;
 280         tv->tv_usec = microsecs;
 281 }
 282
 283 /*
 284  * Get value of an interval timer.  The process virtual and
 285  * profiling virtual time timers are kept internally in the
 286  * way they are specified externally: in time until they expire.
 287  *
 288  * The real time interval timer expiration time (p_rtime)
 289  * is kept as an absolute time rather than as a delta, so that
 290  * it is easy to keep periodic real-time signals from drifting.
 291  *
 292  * The real time timer is processed by a callout routine.
 293  * Since a callout may be delayed in real time due to
 294  * other processing in the system, it is possible for the real
 295  * time callout routine (realitexpire, given below), to be delayed
 296  * in real time past when it is supposed to occur.  It does not
 297  * suffice, therefore, to reload the real time .it_value from the
 298  * real time .it_interval.  Rather, we compute the next time in
 299  * absolute time when the timer should go off.
 300  *
 301  * Returns:     0                       Success
 302  *              EINVAL                  Invalid argument
 303  *      copyout:EFAULT                  Bad address
 304  */
 305 /* ARGSUSED */
 306 int
 307 getitimer(struct proc *p, struct getitimer_args *uap, __unused int32_t *retval)
 308 {
 309         struct itimerval aitv;
 310
 311         if (uap->which > ITIMER_PROF)
 312                 return(EINVAL);
 313
 314         bzero(&aitv, sizeof(aitv));
 315
 316         proc_spinlock(p);
 317         switch (uap->which) {
 318
 319         case ITIMER_REAL:
 320                 /*
 321                  * If time for real time timer has passed return 0,
 322                  * else return difference between current time and
 323                  * time for the timer to go off.
 324                  */
 325                 aitv = p->p_realtimer;
 326                 if (timerisset(&p->p_rtime)) {
 327                         struct timeval          now;
 328
 329                         microuptime(&now);
 330                         if (timercmp(&p->p_rtime, &now, <))
 331                                 timerclear(&aitv.it_value);
 332                         else {
 333                                 aitv.it_value = p->p_rtime;
 334                                 timevalsub(&aitv.it_value, &now);
 335                         }
 336                 }
 337                 else
 338                         timerclear(&aitv.it_value);
 339                 break;
 340
 341         case ITIMER_VIRTUAL:
 342                 aitv = p->p_vtimer_user;
 343                 break;
 344
 345         case ITIMER_PROF:
 346                 aitv = p->p_vtimer_prof;
 347                 break;
 348         }
 349
 350         proc_spinunlock(p);
 351
 352         if (IS_64BIT_PROCESS(p)) {
 353                 struct user64_itimerval user_itv;
 354                 bzero(&user_itv, sizeof (user_itv));
 355                 user_itv.it_interval.tv_sec = aitv.it_interval.tv_sec;
 356                 user_itv.it_interval.tv_usec = aitv.it_interval.tv_usec;
 357                 user_itv.it_value.tv_sec = aitv.it_value.tv_sec;
 358                 user_itv.it_value.tv_usec = aitv.it_value.tv_usec;
 359                 return (copyout((caddr_t)&user_itv, uap->itv, sizeof (user_itv)));
 360         } else {
 361                 struct user32_itimerval user_itv;
 362                 bzero(&user_itv, sizeof (user_itv));
 363                 user_itv.it_interval.tv_sec = aitv.it_interval.tv_sec;
 364                 user_itv.it_interval.tv_usec = aitv.it_interval.tv_usec;
 365                 user_itv.it_value.tv_sec = aitv.it_value.tv_sec;
 366                 user_itv.it_value.tv_usec = aitv.it_value.tv_usec;
 367                 return (copyout((caddr_t)&user_itv, uap->itv, sizeof (user_itv)));
 368         }
 369 }
 370
 371 /*
 372  * Returns:     0                       Success
 373  *              EINVAL                  Invalid argument
 374  *      copyin:EFAULT                   Bad address
 375  *      getitimer:EINVAL                Invalid argument
 376  *      getitimer:EFAULT                Bad address
 377  */
 378 /* ARGSUSED */
 379 int
 380 setitimer(struct proc *p, struct setitimer_args *uap, int32_t *retval)
 381 {
 382         struct itimerval aitv;
 383         user_addr_t itvp;
 384         int error;
 385
 386         bzero(&aitv, sizeof(aitv));
 387
 388         if (uap->which > ITIMER_PROF)
 389                 return (EINVAL);
 390         if ((itvp = uap->itv)) {
 391                 if (IS_64BIT_PROCESS(p)) {
 392                         struct user64_itimerval user_itv;
 393                         if ((error = copyin(itvp, (caddr_t)&user_itv, sizeof (user_itv))))
 394                                 return (error);
 395                         aitv.it_interval.tv_sec = user_itv.it_interval.tv_sec;
 396                         aitv.it_interval.tv_usec = user_itv.it_interval.tv_usec;
 397                         aitv.it_value.tv_sec = user_itv.it_value.tv_sec;
 398                         aitv.it_value.tv_usec = user_itv.it_value.tv_usec;
 399                 } else {
 400                         struct user32_itimerval user_itv;
 401                         if ((error = copyin(itvp, (caddr_t)&user_itv, sizeof (user_itv))))
 402                                 return (error);
 403                         aitv.it_interval.tv_sec = user_itv.it_interval.tv_sec;
 404                         aitv.it_interval.tv_usec = user_itv.it_interval.tv_usec;
 405                         aitv.it_value.tv_sec = user_itv.it_value.tv_sec;
 406                         aitv.it_value.tv_usec = user_itv.it_value.tv_usec;
 407                 }
 408         }
 409         if ((uap->itv = uap->oitv) && (error = getitimer(p, (struct getitimer_args *)uap, retval)))
 410                 return (error);
 411         if (itvp == 0)
 412                 return (0);
 413         if (itimerfix(&aitv.it_value) || itimerfix(&aitv.it_interval))
 414                 return (EINVAL);
 415
 416         switch (uap->which) {
 417
 418         case ITIMER_REAL:
 419                 proc_spinlock(p);
 420                 if (timerisset(&aitv.it_value)) {
 421                         microuptime(&p->p_rtime);
 422                         timevaladd(&p->p_rtime, &aitv.it_value);
 423                         p->p_realtimer = aitv;
 424                         if (!thread_call_enter_delayed_with_leeway(p->p_rcall, NULL,
 425                                                  tvtoabstime(&p->p_rtime), 0, THREAD_CALL_DELAY_USER_NORMAL))
 426                                 p->p_ractive++;
 427                 } else  {
 428                         timerclear(&p->p_rtime);
 429                         p->p_realtimer = aitv;
 430                         if (thread_call_cancel(p->p_rcall))
 431                                 p->p_ractive--;
 432                 }
 433                 proc_spinunlock(p);
 434
 435                 break;
 436
 437
 438         case ITIMER_VIRTUAL:
 439                 if (timerisset(&aitv.it_value))
 440                         task_vtimer_set(p->task, TASK_VTIMER_USER);
 441         else
 442                         task_vtimer_clear(p->task, TASK_VTIMER_USER);
 443
 444                 proc_spinlock(p);
 445                 p->p_vtimer_user = aitv;
 446                 proc_spinunlock(p);
 447                 break;
 448
 449         case ITIMER_PROF:
 450                 if (timerisset(&aitv.it_value))
 451                         task_vtimer_set(p->task, TASK_VTIMER_PROF);
 452                 else
 453                         task_vtimer_clear(p->task, TASK_VTIMER_PROF);
 454
 455                 proc_spinlock(p);
 456                 p->p_vtimer_prof = aitv;
 457                 proc_spinunlock(p);
 458                 break;
 459         }
 460
 461         return (0);
 462 }
 463
 464 /*
 465  * Real interval timer expired:
 466  * send process whose timer expired an alarm signal.
 467  * If time is not set up to reload, then just return.
 468  * Else compute next time timer should go off which is > current time.
 469  * This is where delay in processing this timeout causes multiple
 470  * SIGALRM calls to be compressed into one.
 471  */
 472 void
 473 realitexpire(
 474         struct proc *p)
 475 {
 476         struct proc *r;
 477         struct timeval t;
 478
 479         r = proc_find(p->p_pid);
 480
 481         proc_spinlock(p);
 482
 483         assert(p->p_ractive > 0);
 484
 485         if (--p->p_ractive > 0 || r != p) {
 486                 /*
 487                  * bail, because either proc is exiting
 488                  * or there's another active thread call
 489                  */
 490                 proc_spinunlock(p);
 491
 492                 if (r != NULL)
 493                         proc_rele(r);
 494                 return;
 495         }
 496
 497         if (!timerisset(&p->p_realtimer.it_interval)) {
 498                 /*
 499                  * p_realtimer was cleared while this call was pending,
 500                  * send one last SIGALRM, but don't re-arm
 501                  */
 502                 timerclear(&p->p_rtime);
 503                 proc_spinunlock(p);
 504
 505                 psignal(p, SIGALRM);
 506                 proc_rele(p);
 507                 return;
 508         }
 509
 510         proc_spinunlock(p);
 511
 512         /*
 513          * Send the signal before re-arming the next thread call,
 514          * so in case psignal blocks, we won't create yet another thread call.
 515          */
 516
 517         psignal(p, SIGALRM);
 518
 519         proc_spinlock(p);
 520
 521         /* Should we still re-arm the next thread call? */
 522         if (!timerisset(&p->p_realtimer.it_interval)) {
 523                 timerclear(&p->p_rtime);
 524                 proc_spinunlock(p);
 525
 526                 proc_rele(p);
 527                 return;
 528         }
 529
 530         microuptime(&t);
 531         timevaladd(&p->p_rtime, &p->p_realtimer.it_interval);
 532
 533         if (timercmp(&p->p_rtime, &t, <=)) {
 534                 if ((p->p_rtime.tv_sec + 2) >= t.tv_sec) {
 535                         for (;;) {
 536                                 timevaladd(&p->p_rtime, &p->p_realtimer.it_interval);
 537                                 if (timercmp(&p->p_rtime, &t, >))
 538                                         break;
 539                         }
 540                 } else {
 541                         p->p_rtime = p->p_realtimer.it_interval;
 542                         timevaladd(&p->p_rtime, &t);
 543                 }
 544         }
 545
 546         assert(p->p_rcall != NULL);
 547
 548         if (!thread_call_enter_delayed_with_leeway(p->p_rcall, NULL, tvtoabstime(&p->p_rtime), 0,
 549                                                    THREAD_CALL_DELAY_USER_NORMAL)) {
 550                 p->p_ractive++;
 551         }
 552
 553         proc_spinunlock(p);
 554
 555         proc_rele(p);
 556 }
 557
 558 /*
 559  * Called once in proc_exit to clean up after an armed or pending realitexpire
 560  *
 561  * This will only be called after the proc refcount is drained,
 562  * so realitexpire cannot be currently holding a proc ref.
 563  * i.e. it will/has gotten PROC_NULL from proc_find.
 564  */
 565 void
 566 proc_free_realitimer(proc_t p)
 567 {
 568         proc_spinlock(p);
 569
 570         assert(p->p_rcall != NULL);
 571         assert(p->p_refcount == 0);
 572
 573         timerclear(&p->p_realtimer.it_interval);
 574
 575         if (thread_call_cancel(p->p_rcall)) {
 576                 assert(p->p_ractive > 0);
 577                 p->p_ractive--;
 578         }
 579
 580         while (p->p_ractive > 0) {
 581                 proc_spinunlock(p);
 582
 583                 delay(1);
 584
 585                 proc_spinlock(p);
 586         }
 587
 588         thread_call_t call = p->p_rcall;
 589         p->p_rcall = NULL;
 590
 591         proc_spinunlock(p);
 592
 593         thread_call_free(call);
 594 }
 595
 596 /*
 597  * Check that a proposed value to load into the .it_value or
 598  * .it_interval part of an interval timer is acceptable.
 599  */
 600 int
 601 itimerfix(
 602         struct timeval *tv)
 603 {
 604
 605         if (tv->tv_sec < 0 || tv->tv_sec > 100000000 ||
 606             tv->tv_usec < 0 || tv->tv_usec >= 1000000)
 607                 return (EINVAL);
 608         return (0);
 609 }
 610
 611 int
 612 timespec_is_valid(const struct timespec *ts)
 613 {
 614         /* The INT32_MAX limit ensures the timespec is safe for clock_*() functions
 615          * which accept 32-bit ints. */
 616         if (ts->tv_sec < 0 || ts->tv_sec > INT32_MAX ||
 617                         ts->tv_nsec < 0 || (unsigned long long)ts->tv_nsec > NSEC_PER_SEC) {
 618                 return 0;
 619         }
 620         return 1;
 621 }
 622
 623 /*
 624  * Decrement an interval timer by a specified number
 625  * of microseconds, which must be less than a second,
 626  * i.e. < 1000000.  If the timer expires, then reload
 627  * it.  In this case, carry over (usec - old value) to
 628  * reduce the value reloaded into the timer so that
 629  * the timer does not drift.  This routine assumes
 630  * that it is called in a context where the timers
 631  * on which it is operating cannot change in value.
 632  */
 633 int
 634 itimerdecr(proc_t p,
 635         struct itimerval *itp, int usec)
 636 {
 637
 638         proc_spinlock(p);
 639
 640         if (itp->it_value.tv_usec < usec) {
 641                 if (itp->it_value.tv_sec == 0) {
 642                         /* expired, and already in next interval */
 643                         usec -= itp->it_value.tv_usec;
 644                         goto expire;
 645                 }
 646                 itp->it_value.tv_usec += 1000000;
 647                 itp->it_value.tv_sec--;
 648         }
 649         itp->it_value.tv_usec -= usec;
 650         usec = 0;
 651         if (timerisset(&itp->it_value)) {
 652                 proc_spinunlock(p);
 653                 return (1);
 654         }
 655         /* expired, exactly at end of interval */
 656 expire:
 657         if (timerisset(&itp->it_interval)) {
 658                 itp->it_value = itp->it_interval;
 659                 if (itp->it_value.tv_sec > 0) {
 660                 itp->it_value.tv_usec -= usec;
 661                 if (itp->it_value.tv_usec < 0) {
 662                         itp->it_value.tv_usec += 1000000;
 663                         itp->it_value.tv_sec--;
 664                         }
 665                 }
 666         } else
 667                 itp->it_value.tv_usec = 0;              /* sec is already 0 */
 668         proc_spinunlock(p);
 669         return (0);
 670 }
 671
 672 /*
 673  * Add and subtract routines for timevals.
 674  * N.B.: subtract routine doesn't deal with
 675  * results which are before the beginning,
 676  * it just gets very confused in this case.
 677  * Caveat emptor.
 678  */
 679 void
 680 timevaladd(
 681         struct timeval *t1,
 682         struct timeval *t2)
 683 {
 684
 685         t1->tv_sec += t2->tv_sec;
 686         t1->tv_usec += t2->tv_usec;
 687         timevalfix(t1);
 688 }
 689 void
 690 timevalsub(
 691         struct timeval *t1,
 692         struct timeval *t2)
 693 {
 694
 695         t1->tv_sec -= t2->tv_sec;
 696         t1->tv_usec -= t2->tv_usec;
 697         timevalfix(t1);
 698 }
 699 void
 700 timevalfix(
 701         struct timeval *t1)
 702 {
 703
 704         if (t1->tv_usec < 0) {
 705                 t1->tv_sec--;
 706                 t1->tv_usec += 1000000;
 707         }
 708         if (t1->tv_usec >= 1000000) {
 709                 t1->tv_sec++;
 710                 t1->tv_usec -= 1000000;
 711         }
 712 }
 713
 714 /*
 715  * Return the best possible estimate of the time in the timeval
 716  * to which tvp points.
 717  */
 718 void
 719 microtime(
 720         struct timeval  *tvp)
 721 {
 722         clock_sec_t             tv_sec;
 723         clock_usec_t    tv_usec;
 724
 725         clock_get_calendar_microtime(&tv_sec, &tv_usec);
 726
 727         tvp->tv_sec = tv_sec;
 728         tvp->tv_usec = tv_usec;
 729 }
 730
 731 void
 732 microtime_with_abstime(
 733         struct timeval  *tvp, uint64_t *abstime)
 734 {
 735         clock_sec_t             tv_sec;
 736         clock_usec_t    tv_usec;
 737
 738         clock_get_calendar_absolute_and_microtime(&tv_sec, &tv_usec, abstime);
 739
 740         tvp->tv_sec = tv_sec;
 741         tvp->tv_usec = tv_usec;
 742 }
 743
 744 void
 745 microuptime(
 746         struct timeval  *tvp)
 747 {
 748         clock_sec_t             tv_sec;
 749         clock_usec_t    tv_usec;
 750
 751         clock_get_system_microtime(&tv_sec, &tv_usec);
 752
 753         tvp->tv_sec = tv_sec;
 754         tvp->tv_usec = tv_usec;
 755 }
 756
 757 /*
 758  * Ditto for timespec.
 759  */
 760 void
 761 nanotime(
 762         struct timespec *tsp)
 763 {
 764         clock_sec_t             tv_sec;
 765         clock_nsec_t    tv_nsec;
 766
 767         clock_get_calendar_nanotime(&tv_sec, &tv_nsec);
 768
 769         tsp->tv_sec = tv_sec;
 770         tsp->tv_nsec = tv_nsec;
 771 }
 772
 773 void
 774 nanouptime(
 775         struct timespec *tsp)
 776 {
 777         clock_sec_t             tv_sec;
 778         clock_nsec_t    tv_nsec;
 779
 780         clock_get_system_nanotime(&tv_sec, &tv_nsec);
 781
 782         tsp->tv_sec = tv_sec;
 783         tsp->tv_nsec = tv_nsec;
 784 }
 785
 786 uint64_t
 787 tvtoabstime(
 788         struct timeval  *tvp)
 789 {
 790         uint64_t        result, usresult;
 791
 792         clock_interval_to_absolutetime_interval(
 793                                                 tvp->tv_sec, NSEC_PER_SEC, &result);
 794         clock_interval_to_absolutetime_interval(
 795                                                 tvp->tv_usec, NSEC_PER_USEC, &usresult);
 796
 797         return (result + usresult);
 798 }
 799
 800 uint64_t
 801 tstoabstime(struct timespec *ts)
 802 {
 803         uint64_t abstime_s, abstime_ns;
 804         clock_interval_to_absolutetime_interval(ts->tv_sec, NSEC_PER_SEC, &abstime_s);
 805         clock_interval_to_absolutetime_interval(ts->tv_nsec, 1, &abstime_ns);
 806         return abstime_s + abstime_ns;
 807 }
 808
 809 #if NETWORKING
 810 /*
 811  * ratecheck(): simple time-based rate-limit checking.
 812  */
 813 int
 814 ratecheck(struct timeval *lasttime, const struct timeval *mininterval)
 815 {
 816         struct timeval tv, delta;
 817         int rv = 0;
 818
 819         net_uptime2timeval(&tv);
 820         delta = tv;
 821         timevalsub(&delta, lasttime);
 822
 823         /*
 824          * check for 0,0 is so that the message will be seen at least once,
 825          * even if interval is huge.
 826          */
 827         if (timevalcmp(&delta, mininterval, >=) ||
 828             (lasttime->tv_sec == 0 && lasttime->tv_usec == 0)) {
 829                 *lasttime = tv;
 830                 rv = 1;
 831         }
 832
 833         return (rv);
 834 }
 835
 836 /*
 837  * ppsratecheck(): packets (or events) per second limitation.
 838  */
 839 int
 840 ppsratecheck(struct timeval *lasttime, int *curpps, int maxpps)
 841 {
 842         struct timeval tv, delta;
 843         int rv;
 844
 845         net_uptime2timeval(&tv);
 846
 847         timersub(&tv, lasttime, &delta);
 848
 849         /*
 850          * Check for 0,0 so that the message will be seen at least once.
 851          * If more than one second has passed since the last update of
 852          * lasttime, reset the counter.
 853          *
 854          * we do increment *curpps even in *curpps < maxpps case, as some may
 855          * try to use *curpps for stat purposes as well.
 856          */
 857         if ((lasttime->tv_sec == 0 && lasttime->tv_usec == 0) ||
 858             delta.tv_sec >= 1) {
 859                 *lasttime = tv;
 860                 *curpps = 0;
 861                 rv = 1;
 862         } else if (maxpps < 0)
 863                 rv = 1;
 864         else if (*curpps < maxpps)
 865                 rv = 1;
 866         else
 867                 rv = 0;
 868
 869 #if 1 /* DIAGNOSTIC? */
 870         /* be careful about wrap-around */
 871         if (*curpps + 1 > 0)
 872                 *curpps = *curpps + 1;
 873 #else
 874         /*
 875          * assume that there's not too many calls to this function.
 876          * not sure if the assumption holds, as it depends on *caller's*
 877          * behavior, not the behavior of this function.
 878          * IMHO it is wrong to make assumption on the caller's behavior,
 879          * so the above #if is #if 1, not #ifdef DIAGNOSTIC.
 880          */
 881         *curpps = *curpps + 1;
 882 #endif
 883
 884         return (rv);
 885 }
 886 #endif /* NETWORKING */
 887
 888 void
 889 time_zone_slock_init(void)
 890 {
 891         /* allocate lock group attribute and group */
 892         tz_slock_grp_attr = lck_grp_attr_alloc_init();
 893
 894         tz_slock_grp =  lck_grp_alloc_init("tzlock", tz_slock_grp_attr);
 895
 896         /* Allocate lock attribute */
 897         tz_slock_attr = lck_attr_alloc_init();
 898
 899         /* Allocate the spin lock */
 900         tz_slock = lck_spin_alloc_init(tz_slock_grp, tz_slock_attr);
 901 }