1 /* $OpenBSD: kern_time.c,v 1.162 2023/02/04 19:33:03 cheloha Exp $ */ 2 /* $NetBSD: kern_time.c,v 1.20 1996/02/18 11:57:06 fvdl Exp $ */ 3 4 /* 5 * Copyright (c) 1982, 1986, 1989, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * @(#)kern_time.c 8.4 (Berkeley) 5/26/95 33 */ 34 35 #include <sys/param.h> 36 #include <sys/kernel.h> 37 #include <sys/systm.h> 38 #include <sys/mutex.h> 39 #include <sys/rwlock.h> 40 #include <sys/proc.h> 41 #include <sys/ktrace.h> 42 #include <sys/signalvar.h> 43 #include <sys/stdint.h> 44 #include <sys/pledge.h> 45 #include <sys/task.h> 46 #include <sys/timeout.h> 47 #include <sys/timetc.h> 48 49 #include <sys/mount.h> 50 #include <sys/syscallargs.h> 51 52 #include <dev/clock_subr.h> 53 54 int itimerfix(struct itimerval *); 55 56 /* 57 * Time of day and interval timer support. 58 * 59 * These routines provide the kernel entry points to get and set 60 * the time-of-day and per-process interval timers. Subroutines 61 * here provide support for adding and subtracting timeval structures 62 * and decrementing interval timers, optionally reloading the interval 63 * timers when they expire. 64 */ 65 66 /* This function is used by clock_settime and settimeofday */ 67 int 68 settime(const struct timespec *ts) 69 { 70 struct timespec now; 71 72 /* 73 * Don't allow the time to be set forward so far it will wrap 74 * and become negative, thus allowing an attacker to bypass 75 * the next check below. The cutoff is 1 year before rollover 76 * occurs, so even if the attacker uses adjtime(2) to move 77 * the time past the cutoff, it will take a very long time 78 * to get to the wrap point. 79 * 80 * XXX: we check against UINT_MAX until we can figure out 81 * how to deal with the hardware RTCs. 82 */ 83 if (ts->tv_sec > UINT_MAX - 365*24*60*60) { 84 printf("denied attempt to set clock forward to %lld\n", 85 (long long)ts->tv_sec); 86 return (EPERM); 87 } 88 /* 89 * If the system is secure, we do not allow the time to be 90 * set to an earlier value (it may be slowed using adjtime, 91 * but not set back). This feature prevent interlopers from 92 * setting arbitrary time stamps on files. 93 */ 94 nanotime(&now); 95 if (securelevel > 1 && timespeccmp(ts, &now, <=)) { 96 printf("denied attempt to set clock back %lld seconds\n", 97 (long long)now.tv_sec - ts->tv_sec); 98 return (EPERM); 99 } 100 101 tc_setrealtimeclock(ts); 102 KERNEL_LOCK(); 103 resettodr(); 104 KERNEL_UNLOCK(); 105 106 return (0); 107 } 108 109 int 110 clock_gettime(struct proc *p, clockid_t clock_id, struct timespec *tp) 111 { 112 struct proc *q; 113 int error = 0; 114 115 switch (clock_id) { 116 case CLOCK_REALTIME: 117 nanotime(tp); 118 break; 119 case CLOCK_UPTIME: 120 nanoruntime(tp); 121 break; 122 case CLOCK_MONOTONIC: 123 case CLOCK_BOOTTIME: 124 nanouptime(tp); 125 break; 126 case CLOCK_PROCESS_CPUTIME_ID: 127 nanouptime(tp); 128 timespecsub(tp, &curcpu()->ci_schedstate.spc_runtime, tp); 129 timespecadd(tp, &p->p_p->ps_tu.tu_runtime, tp); 130 timespecadd(tp, &p->p_rtime, tp); 131 break; 132 case CLOCK_THREAD_CPUTIME_ID: 133 nanouptime(tp); 134 timespecsub(tp, &curcpu()->ci_schedstate.spc_runtime, tp); 135 timespecadd(tp, &p->p_tu.tu_runtime, tp); 136 timespecadd(tp, &p->p_rtime, tp); 137 break; 138 default: 139 /* check for clock from pthread_getcpuclockid() */ 140 if (__CLOCK_TYPE(clock_id) == CLOCK_THREAD_CPUTIME_ID) { 141 KERNEL_LOCK(); 142 q = tfind_user(__CLOCK_PTID(clock_id), p->p_p); 143 if (q == NULL) 144 error = ESRCH; 145 else 146 *tp = q->p_tu.tu_runtime; 147 KERNEL_UNLOCK(); 148 } else 149 error = EINVAL; 150 break; 151 } 152 return (error); 153 } 154 155 int 156 sys_clock_gettime(struct proc *p, void *v, register_t *retval) 157 { 158 struct sys_clock_gettime_args /* { 159 syscallarg(clockid_t) clock_id; 160 syscallarg(struct timespec *) tp; 161 } */ *uap = v; 162 struct timespec ats; 163 int error; 164 165 memset(&ats, 0, sizeof(ats)); 166 if ((error = clock_gettime(p, SCARG(uap, clock_id), &ats)) != 0) 167 return (error); 168 169 error = copyout(&ats, SCARG(uap, tp), sizeof(ats)); 170 #ifdef KTRACE 171 if (error == 0 && KTRPOINT(p, KTR_STRUCT)) 172 ktrabstimespec(p, &ats); 173 #endif 174 return (error); 175 } 176 177 int 178 sys_clock_settime(struct proc *p, void *v, register_t *retval) 179 { 180 struct sys_clock_settime_args /* { 181 syscallarg(clockid_t) clock_id; 182 syscallarg(const struct timespec *) tp; 183 } */ *uap = v; 184 struct timespec ats; 185 clockid_t clock_id; 186 int error; 187 188 if ((error = suser(p)) != 0) 189 return (error); 190 191 if ((error = copyin(SCARG(uap, tp), &ats, sizeof(ats))) != 0) 192 return (error); 193 194 clock_id = SCARG(uap, clock_id); 195 switch (clock_id) { 196 case CLOCK_REALTIME: 197 if (!timespecisvalid(&ats)) 198 return (EINVAL); 199 if ((error = settime(&ats)) != 0) 200 return (error); 201 break; 202 default: /* Other clocks are read-only */ 203 return (EINVAL); 204 } 205 206 return (0); 207 } 208 209 int 210 sys_clock_getres(struct proc *p, void *v, register_t *retval) 211 { 212 struct sys_clock_getres_args /* { 213 syscallarg(clockid_t) clock_id; 214 syscallarg(struct timespec *) tp; 215 } */ *uap = v; 216 clockid_t clock_id; 217 struct bintime bt; 218 struct timespec ts; 219 struct proc *q; 220 u_int64_t scale; 221 int error = 0; 222 223 memset(&ts, 0, sizeof(ts)); 224 clock_id = SCARG(uap, clock_id); 225 226 switch (clock_id) { 227 case CLOCK_REALTIME: 228 case CLOCK_MONOTONIC: 229 case CLOCK_BOOTTIME: 230 case CLOCK_UPTIME: 231 memset(&bt, 0, sizeof(bt)); 232 rw_enter_read(&tc_lock); 233 scale = ((1ULL << 63) / tc_getfrequency()) * 2; 234 bt.frac = tc_getprecision() * scale; 235 rw_exit_read(&tc_lock); 236 BINTIME_TO_TIMESPEC(&bt, &ts); 237 break; 238 case CLOCK_PROCESS_CPUTIME_ID: 239 case CLOCK_THREAD_CPUTIME_ID: 240 ts.tv_nsec = 1000000000 / stathz; 241 break; 242 default: 243 /* check for clock from pthread_getcpuclockid() */ 244 if (__CLOCK_TYPE(clock_id) == CLOCK_THREAD_CPUTIME_ID) { 245 KERNEL_LOCK(); 246 q = tfind_user(__CLOCK_PTID(clock_id), p->p_p); 247 if (q == NULL) 248 error = ESRCH; 249 else 250 ts.tv_nsec = 1000000000 / stathz; 251 KERNEL_UNLOCK(); 252 } else 253 error = EINVAL; 254 break; 255 } 256 257 if (error == 0 && SCARG(uap, tp)) { 258 ts.tv_nsec = MAX(ts.tv_nsec, 1); 259 error = copyout(&ts, SCARG(uap, tp), sizeof(ts)); 260 #ifdef KTRACE 261 if (error == 0 && KTRPOINT(p, KTR_STRUCT)) 262 ktrreltimespec(p, &ts); 263 #endif 264 } 265 266 return error; 267 } 268 269 int 270 sys_nanosleep(struct proc *p, void *v, register_t *retval) 271 { 272 static int chan; 273 struct sys_nanosleep_args/* { 274 syscallarg(const struct timespec *) rqtp; 275 syscallarg(struct timespec *) rmtp; 276 } */ *uap = v; 277 struct timespec elapsed, remainder, request, start, stop; 278 uint64_t nsecs; 279 struct timespec *rmtp; 280 int copyout_error, error; 281 282 rmtp = SCARG(uap, rmtp); 283 error = copyin(SCARG(uap, rqtp), &request, sizeof(request)); 284 if (error) 285 return (error); 286 #ifdef KTRACE 287 if (KTRPOINT(p, KTR_STRUCT)) 288 ktrreltimespec(p, &request); 289 #endif 290 291 if (request.tv_sec < 0 || !timespecisvalid(&request)) 292 return (EINVAL); 293 294 do { 295 getnanouptime(&start); 296 nsecs = MAX(1, MIN(TIMESPEC_TO_NSEC(&request), MAXTSLP)); 297 error = tsleep_nsec(&chan, PWAIT | PCATCH, "nanoslp", nsecs); 298 getnanouptime(&stop); 299 timespecsub(&stop, &start, &elapsed); 300 timespecsub(&request, &elapsed, &request); 301 if (request.tv_sec < 0) 302 timespecclear(&request); 303 if (error != EWOULDBLOCK) 304 break; 305 } while (timespecisset(&request)); 306 307 if (error == ERESTART) 308 error = EINTR; 309 if (error == EWOULDBLOCK) 310 error = 0; 311 312 if (rmtp) { 313 memset(&remainder, 0, sizeof(remainder)); 314 remainder = request; 315 copyout_error = copyout(&remainder, rmtp, sizeof(remainder)); 316 if (copyout_error) 317 error = copyout_error; 318 #ifdef KTRACE 319 if (copyout_error == 0 && KTRPOINT(p, KTR_STRUCT)) 320 ktrreltimespec(p, &remainder); 321 #endif 322 } 323 324 return error; 325 } 326 327 int 328 sys_gettimeofday(struct proc *p, void *v, register_t *retval) 329 { 330 struct sys_gettimeofday_args /* { 331 syscallarg(struct timeval *) tp; 332 syscallarg(struct timezone *) tzp; 333 } */ *uap = v; 334 struct timeval atv; 335 static const struct timezone zerotz = { 0, 0 }; 336 struct timeval *tp; 337 struct timezone *tzp; 338 int error = 0; 339 340 tp = SCARG(uap, tp); 341 tzp = SCARG(uap, tzp); 342 343 if (tp) { 344 memset(&atv, 0, sizeof(atv)); 345 microtime(&atv); 346 if ((error = copyout(&atv, tp, sizeof (atv)))) 347 return (error); 348 #ifdef KTRACE 349 if (KTRPOINT(p, KTR_STRUCT)) 350 ktrabstimeval(p, &atv); 351 #endif 352 } 353 if (tzp) 354 error = copyout(&zerotz, tzp, sizeof(zerotz)); 355 return (error); 356 } 357 358 int 359 sys_settimeofday(struct proc *p, void *v, register_t *retval) 360 { 361 struct sys_settimeofday_args /* { 362 syscallarg(const struct timeval *) tv; 363 syscallarg(const struct timezone *) tzp; 364 } */ *uap = v; 365 struct timezone atz; 366 struct timeval atv; 367 const struct timeval *tv; 368 const struct timezone *tzp; 369 int error; 370 371 tv = SCARG(uap, tv); 372 tzp = SCARG(uap, tzp); 373 374 if ((error = suser(p))) 375 return (error); 376 /* Verify all parameters before changing time. */ 377 if (tv && (error = copyin(tv, &atv, sizeof(atv)))) 378 return (error); 379 if (tzp && (error = copyin(tzp, &atz, sizeof(atz)))) 380 return (error); 381 if (tv) { 382 struct timespec ts; 383 384 #ifdef KTRACE 385 if (KTRPOINT(p, KTR_STRUCT)) 386 ktrabstimeval(p, &atv); 387 #endif 388 if (!timerisvalid(&atv)) 389 return (EINVAL); 390 TIMEVAL_TO_TIMESPEC(&atv, &ts); 391 if ((error = settime(&ts)) != 0) 392 return (error); 393 } 394 395 return (0); 396 } 397 398 #define ADJFREQ_MAX (500000000LL << 32) 399 #define ADJFREQ_MIN (-ADJFREQ_MAX) 400 401 int 402 sys_adjfreq(struct proc *p, void *v, register_t *retval) 403 { 404 struct sys_adjfreq_args /* { 405 syscallarg(const int64_t *) freq; 406 syscallarg(int64_t *) oldfreq; 407 } */ *uap = v; 408 int error = 0; 409 int64_t f, oldf; 410 const int64_t *freq = SCARG(uap, freq); 411 int64_t *oldfreq = SCARG(uap, oldfreq); 412 413 if (freq) { 414 if ((error = suser(p))) 415 return (error); 416 if ((error = copyin(freq, &f, sizeof(f)))) 417 return (error); 418 if (f < ADJFREQ_MIN || f > ADJFREQ_MAX) 419 return (EINVAL); 420 } 421 422 rw_enter(&tc_lock, (freq == NULL) ? RW_READ : RW_WRITE); 423 if (oldfreq) { 424 tc_adjfreq(&oldf, NULL); 425 if ((error = copyout(&oldf, oldfreq, sizeof(oldf)))) 426 goto out; 427 } 428 if (freq) 429 tc_adjfreq(NULL, &f); 430 out: 431 rw_exit(&tc_lock); 432 return (error); 433 } 434 435 int 436 sys_adjtime(struct proc *p, void *v, register_t *retval) 437 { 438 struct sys_adjtime_args /* { 439 syscallarg(const struct timeval *) delta; 440 syscallarg(struct timeval *) olddelta; 441 } */ *uap = v; 442 struct timeval atv; 443 const struct timeval *delta = SCARG(uap, delta); 444 struct timeval *olddelta = SCARG(uap, olddelta); 445 int64_t adjustment, remaining; 446 int error; 447 448 error = pledge_adjtime(p, delta); 449 if (error) 450 return error; 451 452 if (delta) { 453 if ((error = suser(p))) 454 return (error); 455 if ((error = copyin(delta, &atv, sizeof(struct timeval)))) 456 return (error); 457 #ifdef KTRACE 458 if (KTRPOINT(p, KTR_STRUCT)) 459 ktrreltimeval(p, &atv); 460 #endif 461 if (!timerisvalid(&atv)) 462 return (EINVAL); 463 464 if (atv.tv_sec > INT64_MAX / 1000000) 465 return EINVAL; 466 if (atv.tv_sec < INT64_MIN / 1000000) 467 return EINVAL; 468 adjustment = atv.tv_sec * 1000000; 469 if (adjustment > INT64_MAX - atv.tv_usec) 470 return EINVAL; 471 adjustment += atv.tv_usec; 472 473 rw_enter_write(&tc_lock); 474 } 475 476 if (olddelta) { 477 tc_adjtime(&remaining, NULL); 478 memset(&atv, 0, sizeof(atv)); 479 atv.tv_sec = remaining / 1000000; 480 atv.tv_usec = remaining % 1000000; 481 if (atv.tv_usec < 0) { 482 atv.tv_usec += 1000000; 483 atv.tv_sec--; 484 } 485 486 if ((error = copyout(&atv, olddelta, sizeof(struct timeval)))) 487 goto out; 488 } 489 490 if (delta) 491 tc_adjtime(NULL, &adjustment); 492 out: 493 if (delta) 494 rw_exit_write(&tc_lock); 495 return (error); 496 } 497 498 499 struct mutex itimer_mtx = MUTEX_INITIALIZER(IPL_CLOCK); 500 501 /* 502 * Get or set value of an interval timer. The process virtual and 503 * profiling virtual time timers are kept internally in the 504 * way they are specified externally: in time until they expire. 505 * 506 * The real time interval timer's it_value, in contrast, is kept as an 507 * absolute time rather than as a delta, so that it is easy to keep 508 * periodic real-time signals from drifting. 509 * 510 * Virtual time timers are processed in the hardclock() routine of 511 * kern_clock.c. The real time timer is processed by a timeout 512 * routine, called from the softclock() routine. Since a callout 513 * may be delayed in real time due to interrupt processing in the system, 514 * it is possible for the real time timeout routine (realitexpire, given below), 515 * to be delayed in real time past when it is supposed to occur. It 516 * does not suffice, therefore, to reload the real timer .it_value from the 517 * real time timers .it_interval. Rather, we compute the next time in 518 * absolute time the timer should go off. 519 */ 520 void 521 setitimer(int which, const struct itimerval *itv, struct itimerval *olditv) 522 { 523 struct itimerspec its, oldits; 524 struct timespec now; 525 struct itimerspec *itimer; 526 struct process *pr; 527 528 KASSERT(which >= ITIMER_REAL && which <= ITIMER_PROF); 529 530 pr = curproc->p_p; 531 itimer = &pr->ps_timer[which]; 532 533 if (itv != NULL) { 534 TIMEVAL_TO_TIMESPEC(&itv->it_value, &its.it_value); 535 TIMEVAL_TO_TIMESPEC(&itv->it_interval, &its.it_interval); 536 } 537 538 if (which == ITIMER_REAL) { 539 mtx_enter(&pr->ps_mtx); 540 nanouptime(&now); 541 } else 542 mtx_enter(&itimer_mtx); 543 544 if (olditv != NULL) 545 oldits = *itimer; 546 if (itv != NULL) { 547 if (which == ITIMER_REAL) { 548 if (timespecisset(&its.it_value)) { 549 timespecadd(&its.it_value, &now, &its.it_value); 550 timeout_abs_ts(&pr->ps_realit_to,&its.it_value); 551 } else 552 timeout_del(&pr->ps_realit_to); 553 } 554 *itimer = its; 555 } 556 557 if (which == ITIMER_REAL) 558 mtx_leave(&pr->ps_mtx); 559 else 560 mtx_leave(&itimer_mtx); 561 562 if (olditv != NULL) { 563 if (which == ITIMER_REAL && timespecisset(&oldits.it_value)) { 564 if (timespeccmp(&oldits.it_value, &now, <)) 565 timespecclear(&oldits.it_value); 566 else { 567 timespecsub(&oldits.it_value, &now, 568 &oldits.it_value); 569 } 570 } 571 TIMESPEC_TO_TIMEVAL(&olditv->it_value, &oldits.it_value); 572 TIMESPEC_TO_TIMEVAL(&olditv->it_interval, &oldits.it_interval); 573 } 574 } 575 576 void 577 cancel_all_itimers(void) 578 { 579 struct itimerval itv; 580 int i; 581 582 timerclear(&itv.it_value); 583 timerclear(&itv.it_interval); 584 585 for (i = 0; i < nitems(curproc->p_p->ps_timer); i++) 586 setitimer(i, &itv, NULL); 587 } 588 589 int 590 sys_getitimer(struct proc *p, void *v, register_t *retval) 591 { 592 struct sys_getitimer_args /* { 593 syscallarg(int) which; 594 syscallarg(struct itimerval *) itv; 595 } */ *uap = v; 596 struct itimerval aitv; 597 int which; 598 599 which = SCARG(uap, which); 600 if (which < ITIMER_REAL || which > ITIMER_PROF) 601 return EINVAL; 602 603 memset(&aitv, 0, sizeof(aitv)); 604 605 setitimer(which, NULL, &aitv); 606 607 return copyout(&aitv, SCARG(uap, itv), sizeof(aitv)); 608 } 609 610 int 611 sys_setitimer(struct proc *p, void *v, register_t *retval) 612 { 613 struct sys_setitimer_args /* { 614 syscallarg(int) which; 615 syscallarg(const struct itimerval *) itv; 616 syscallarg(struct itimerval *) oitv; 617 } */ *uap = v; 618 struct itimerval aitv, olditv; 619 struct itimerval *newitvp, *olditvp; 620 int error, which; 621 622 which = SCARG(uap, which); 623 if (which < ITIMER_REAL || which > ITIMER_PROF) 624 return EINVAL; 625 626 newitvp = olditvp = NULL; 627 if (SCARG(uap, itv) != NULL) { 628 error = copyin(SCARG(uap, itv), &aitv, sizeof(aitv)); 629 if (error) 630 return error; 631 error = itimerfix(&aitv); 632 if (error) 633 return error; 634 newitvp = &aitv; 635 } 636 if (SCARG(uap, oitv) != NULL) { 637 memset(&olditv, 0, sizeof(olditv)); 638 olditvp = &olditv; 639 } 640 if (newitvp == NULL && olditvp == NULL) 641 return 0; 642 643 setitimer(which, newitvp, olditvp); 644 645 if (SCARG(uap, oitv) != NULL) 646 return copyout(&olditv, SCARG(uap, oitv), sizeof(olditv)); 647 648 return 0; 649 } 650 651 /* 652 * Real interval timer expired: 653 * send process whose timer expired an alarm signal. 654 * If time is not set up to reload, then just return. 655 * Else compute next time timer should go off which is > current time. 656 * This is where delay in processing this timeout causes multiple 657 * SIGALRM calls to be compressed into one. 658 */ 659 void 660 realitexpire(void *arg) 661 { 662 struct timespec cts; 663 struct process *pr = arg; 664 struct itimerspec *tp = &pr->ps_timer[ITIMER_REAL]; 665 int need_signal = 0; 666 667 mtx_enter(&pr->ps_mtx); 668 669 /* 670 * Do nothing if the timer was cancelled or rescheduled while we 671 * were entering the mutex. 672 */ 673 if (!timespecisset(&tp->it_value) || timeout_pending(&pr->ps_realit_to)) 674 goto out; 675 676 /* The timer expired. We need to send the signal. */ 677 need_signal = 1; 678 679 /* One-shot timers are not reloaded. */ 680 if (!timespecisset(&tp->it_interval)) { 681 timespecclear(&tp->it_value); 682 goto out; 683 } 684 685 /* 686 * Find the nearest future expiration point and restart 687 * the timeout. 688 */ 689 nanouptime(&cts); 690 while (timespeccmp(&tp->it_value, &cts, <=)) 691 timespecadd(&tp->it_value, &tp->it_interval, &tp->it_value); 692 if ((pr->ps_flags & PS_EXITING) == 0) 693 timeout_abs_ts(&pr->ps_realit_to, &tp->it_value); 694 695 out: 696 mtx_leave(&pr->ps_mtx); 697 698 if (need_signal) 699 prsignal(pr, SIGALRM); 700 } 701 702 /* 703 * Check if the given setitimer(2) input is valid. Clear it_interval 704 * if it_value is unset. Round it_interval up to the minimum interval 705 * if necessary. 706 */ 707 int 708 itimerfix(struct itimerval *itv) 709 { 710 static const struct timeval max = { .tv_sec = UINT_MAX, .tv_usec = 0 }; 711 struct timeval min_interval = { .tv_sec = 0, .tv_usec = tick }; 712 713 if (itv->it_value.tv_sec < 0 || !timerisvalid(&itv->it_value)) 714 return EINVAL; 715 if (timercmp(&itv->it_value, &max, >)) 716 return EINVAL; 717 if (itv->it_interval.tv_sec < 0 || !timerisvalid(&itv->it_interval)) 718 return EINVAL; 719 if (timercmp(&itv->it_interval, &max, >)) 720 return EINVAL; 721 722 if (!timerisset(&itv->it_value)) 723 timerclear(&itv->it_interval); 724 if (timerisset(&itv->it_interval)) { 725 if (timercmp(&itv->it_interval, &min_interval, <)) 726 itv->it_interval = min_interval; 727 } 728 729 return 0; 730 } 731 732 /* 733 * Decrement an interval timer by the given number of nanoseconds. 734 * If the timer expires and it is periodic then reload it. When reloading 735 * the timer we subtract any overrun from the next period so that the timer 736 * does not drift. 737 */ 738 int 739 itimerdecr(struct itimerspec *itp, long nsec) 740 { 741 struct timespec decrement; 742 743 NSEC_TO_TIMESPEC(nsec, &decrement); 744 745 mtx_enter(&itimer_mtx); 746 747 /* 748 * Double-check that the timer is enabled. A different thread 749 * in setitimer(2) may have disabled it while we were entering 750 * the mutex. 751 */ 752 if (!timespecisset(&itp->it_value)) { 753 mtx_leave(&itimer_mtx); 754 return (1); 755 } 756 757 /* 758 * The timer is enabled. Update and reload it as needed. 759 */ 760 timespecsub(&itp->it_value, &decrement, &itp->it_value); 761 if (itp->it_value.tv_sec >= 0 && timespecisset(&itp->it_value)) { 762 mtx_leave(&itimer_mtx); 763 return (1); 764 } 765 if (!timespecisset(&itp->it_interval)) { 766 timespecclear(&itp->it_value); 767 mtx_leave(&itimer_mtx); 768 return (0); 769 } 770 while (itp->it_value.tv_sec < 0 || !timespecisset(&itp->it_value)) 771 timespecadd(&itp->it_value, &itp->it_interval, &itp->it_value); 772 mtx_leave(&itimer_mtx); 773 return (0); 774 } 775 776 struct mutex ratecheck_mtx = MUTEX_INITIALIZER(IPL_HIGH); 777 778 /* 779 * ratecheck(): simple time-based rate-limit checking. see ratecheck(9) 780 * for usage and rationale. 781 */ 782 int 783 ratecheck(struct timeval *lasttime, const struct timeval *mininterval) 784 { 785 struct timeval tv, delta; 786 int rv = 0; 787 788 getmicrouptime(&tv); 789 790 mtx_enter(&ratecheck_mtx); 791 timersub(&tv, lasttime, &delta); 792 793 /* 794 * check for 0,0 is so that the message will be seen at least once, 795 * even if interval is huge. 796 */ 797 if (timercmp(&delta, mininterval, >=) || 798 (lasttime->tv_sec == 0 && lasttime->tv_usec == 0)) { 799 *lasttime = tv; 800 rv = 1; 801 } 802 mtx_leave(&ratecheck_mtx); 803 804 return (rv); 805 } 806 807 struct mutex ppsratecheck_mtx = MUTEX_INITIALIZER(IPL_HIGH); 808 809 /* 810 * ppsratecheck(): packets (or events) per second limitation. 811 */ 812 int 813 ppsratecheck(struct timeval *lasttime, int *curpps, int maxpps) 814 { 815 struct timeval tv, delta; 816 int rv; 817 818 microuptime(&tv); 819 820 mtx_enter(&ppsratecheck_mtx); 821 timersub(&tv, lasttime, &delta); 822 823 /* 824 * check for 0,0 is so that the message will be seen at least once. 825 * if more than one second have passed since the last update of 826 * lasttime, reset the counter. 827 * 828 * we do increment *curpps even in *curpps < maxpps case, as some may 829 * try to use *curpps for stat purposes as well. 830 */ 831 if (maxpps == 0) 832 rv = 0; 833 else if ((lasttime->tv_sec == 0 && lasttime->tv_usec == 0) || 834 delta.tv_sec >= 1) { 835 *lasttime = tv; 836 *curpps = 0; 837 rv = 1; 838 } else if (maxpps < 0) 839 rv = 1; 840 else if (*curpps < maxpps) 841 rv = 1; 842 else 843 rv = 0; 844 845 /* be careful about wrap-around */ 846 if (*curpps + 1 > *curpps) 847 *curpps = *curpps + 1; 848 849 mtx_leave(&ppsratecheck_mtx); 850 851 return (rv); 852 } 853 854 todr_chip_handle_t todr_handle; 855 int inittodr_done; 856 857 #define MINYEAR ((OpenBSD / 100) - 1) /* minimum plausible year */ 858 859 /* 860 * inittodr: 861 * 862 * Initialize time from the time-of-day register. 863 */ 864 void 865 inittodr(time_t base) 866 { 867 time_t deltat; 868 struct timeval rtctime; 869 struct timespec ts; 870 int badbase; 871 872 inittodr_done = 1; 873 874 if (base < (MINYEAR - 1970) * SECYR) { 875 printf("WARNING: preposterous time in file system\n"); 876 /* read the system clock anyway */ 877 base = (MINYEAR - 1970) * SECYR; 878 badbase = 1; 879 } else 880 badbase = 0; 881 882 rtctime.tv_sec = base; 883 rtctime.tv_usec = 0; 884 885 if (todr_handle == NULL || 886 todr_gettime(todr_handle, &rtctime) != 0 || 887 rtctime.tv_sec < (MINYEAR - 1970) * SECYR) { 888 /* 889 * Believe the time in the file system for lack of 890 * anything better, resetting the TODR. 891 */ 892 rtctime.tv_sec = base; 893 rtctime.tv_usec = 0; 894 if (todr_handle != NULL && !badbase) 895 printf("WARNING: bad clock chip time\n"); 896 ts.tv_sec = rtctime.tv_sec; 897 ts.tv_nsec = rtctime.tv_usec * 1000; 898 tc_setclock(&ts); 899 goto bad; 900 } else { 901 ts.tv_sec = rtctime.tv_sec; 902 ts.tv_nsec = rtctime.tv_usec * 1000; 903 tc_setclock(&ts); 904 } 905 906 if (!badbase) { 907 /* 908 * See if we gained/lost two or more days; if 909 * so, assume something is amiss. 910 */ 911 deltat = rtctime.tv_sec - base; 912 if (deltat < 0) 913 deltat = -deltat; 914 if (deltat < 2 * SECDAY) 915 return; /* all is well */ 916 #ifndef SMALL_KERNEL 917 printf("WARNING: clock %s %lld days\n", 918 rtctime.tv_sec < base ? "lost" : "gained", 919 (long long)(deltat / SECDAY)); 920 #endif 921 } 922 bad: 923 printf("WARNING: CHECK AND RESET THE DATE!\n"); 924 } 925 926 /* 927 * resettodr: 928 * 929 * Reset the time-of-day register with the current time. 930 */ 931 void 932 resettodr(void) 933 { 934 struct timeval rtctime; 935 936 /* 937 * Skip writing the RTC if inittodr(9) never ran. We don't 938 * want to overwrite a reasonable value with a nonsense value. 939 */ 940 if (!inittodr_done) 941 return; 942 943 microtime(&rtctime); 944 945 if (todr_handle != NULL && 946 todr_settime(todr_handle, &rtctime) != 0) 947 printf("WARNING: can't update clock chip time\n"); 948 } 949 950 void 951 todr_attach(struct todr_chip_handle *todr) 952 { 953 if (todr_handle == NULL || 954 todr->todr_quality > todr_handle->todr_quality) 955 todr_handle = todr; 956 } 957 958 #define RESETTODR_PERIOD 1800 959 960 void periodic_resettodr(void *); 961 void perform_resettodr(void *); 962 963 struct timeout resettodr_to = TIMEOUT_INITIALIZER(periodic_resettodr, NULL); 964 struct task resettodr_task = TASK_INITIALIZER(perform_resettodr, NULL); 965 966 void 967 periodic_resettodr(void *arg __unused) 968 { 969 task_add(systq, &resettodr_task); 970 } 971 972 void 973 perform_resettodr(void *arg __unused) 974 { 975 resettodr(); 976 timeout_add_sec(&resettodr_to, RESETTODR_PERIOD); 977 } 978 979 void 980 start_periodic_resettodr(void) 981 { 982 timeout_add_sec(&resettodr_to, RESETTODR_PERIOD); 983 } 984 985 void 986 stop_periodic_resettodr(void) 987 { 988 timeout_del(&resettodr_to); 989 task_del(systq, &resettodr_task); 990 } 991