1 /* $NetBSD: kern_time.c,v 1.62 2002/10/22 03:23:24 simonb Exp $ */ 2 3 /*- 4 * Copyright (c) 2000 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Christopher G. Demetriou. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the NetBSD 21 * Foundation, Inc. and its contributors. 22 * 4. Neither the name of The NetBSD Foundation nor the names of its 23 * contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39 /* 40 * Copyright (c) 1982, 1986, 1989, 1993 41 * The Regents of the University of California. All rights reserved. 42 * 43 * Redistribution and use in source and binary forms, with or without 44 * modification, are permitted provided that the following conditions 45 * are met: 46 * 1. Redistributions of source code must retain the above copyright 47 * notice, this list of conditions and the following disclaimer. 48 * 2. Redistributions in binary form must reproduce the above copyright 49 * notice, this list of conditions and the following disclaimer in the 50 * documentation and/or other materials provided with the distribution. 51 * 3. All advertising materials mentioning features or use of this software 52 * must display the following acknowledgement: 53 * This product includes software developed by the University of 54 * California, Berkeley and its contributors. 55 * 4. Neither the name of the University nor the names of its contributors 56 * may be used to endorse or promote products derived from this software 57 * without specific prior written permission. 58 * 59 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 60 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 61 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 62 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 63 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 64 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 65 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 66 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 67 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 68 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 69 * SUCH DAMAGE. 70 * 71 * @(#)kern_time.c 8.4 (Berkeley) 5/26/95 72 */ 73 74 #include <sys/cdefs.h> 75 __KERNEL_RCSID(0, "$NetBSD: kern_time.c,v 1.62 2002/10/22 03:23:24 simonb Exp $"); 76 77 #include "fs_nfs.h" 78 #include "opt_nfs.h" 79 #include "opt_nfsserver.h" 80 81 #include <sys/param.h> 82 #include <sys/resourcevar.h> 83 #include <sys/kernel.h> 84 #include <sys/systm.h> 85 #include <sys/proc.h> 86 #include <sys/vnode.h> 87 #include <sys/signalvar.h> 88 #include <sys/syslog.h> 89 90 #include <sys/mount.h> 91 #include <sys/syscallargs.h> 92 93 #include <uvm/uvm_extern.h> 94 95 #if defined(NFS) || defined(NFSSERVER) 96 #include <nfs/rpcv2.h> 97 #include <nfs/nfsproto.h> 98 #include <nfs/nfs_var.h> 99 #endif 100 101 #include <machine/cpu.h> 102 103 /* 104 * Time of day and interval timer support. 105 * 106 * These routines provide the kernel entry points to get and set 107 * the time-of-day and per-process interval timers. Subroutines 108 * here provide support for adding and subtracting timeval structures 109 * and decrementing interval timers, optionally reloading the interval 110 * timers when they expire. 111 */ 112 113 /* This function is used by clock_settime and settimeofday */ 114 int 115 settime(tv) 116 struct timeval *tv; 117 { 118 struct timeval delta; 119 struct cpu_info *ci; 120 int s; 121 122 /* WHAT DO WE DO ABOUT PENDING REAL-TIME TIMEOUTS??? */ 123 s = splclock(); 124 timersub(tv, &time, &delta); 125 if ((delta.tv_sec < 0 || delta.tv_usec < 0) && securelevel > 1) { 126 splx(s); 127 return (EPERM); 128 } 129 #ifdef notyet 130 if ((delta.tv_sec < 86400) && securelevel > 0) { 131 splx(s); 132 return (EPERM); 133 } 134 #endif 135 time = *tv; 136 (void) spllowersoftclock(); 137 timeradd(&boottime, &delta, &boottime); 138 /* 139 * XXXSMP 140 * This is wrong. We should traverse a list of all 141 * CPUs and add the delta to the runtime of those 142 * CPUs which have a process on them. 143 */ 144 ci = curcpu(); 145 timeradd(&ci->ci_schedstate.spc_runtime, &delta, 146 &ci->ci_schedstate.spc_runtime); 147 # if (defined(NFS) && !defined (NFS_V2_ONLY)) || defined(NFSSERVER) 148 nqnfs_lease_updatetime(delta.tv_sec); 149 # endif 150 splx(s); 151 resettodr(); 152 return (0); 153 } 154 155 /* ARGSUSED */ 156 int 157 sys_clock_gettime(p, v, retval) 158 struct proc *p; 159 void *v; 160 register_t *retval; 161 { 162 struct sys_clock_gettime_args /* { 163 syscallarg(clockid_t) clock_id; 164 syscallarg(struct timespec *) tp; 165 } */ *uap = v; 166 clockid_t clock_id; 167 struct timeval atv; 168 struct timespec ats; 169 int s; 170 171 clock_id = SCARG(uap, clock_id); 172 switch (clock_id) { 173 case CLOCK_REALTIME: 174 microtime(&atv); 175 TIMEVAL_TO_TIMESPEC(&atv,&ats); 176 break; 177 case CLOCK_MONOTONIC: 178 /* XXX "hz" granularity */ 179 s = splclock(); 180 atv = mono_time; 181 splx(s); 182 TIMEVAL_TO_TIMESPEC(&atv,&ats); 183 break; 184 default: 185 return (EINVAL); 186 } 187 188 return copyout(&ats, SCARG(uap, tp), sizeof(ats)); 189 } 190 191 /* ARGSUSED */ 192 int 193 sys_clock_settime(p, v, retval) 194 struct proc *p; 195 void *v; 196 register_t *retval; 197 { 198 struct sys_clock_settime_args /* { 199 syscallarg(clockid_t) clock_id; 200 syscallarg(const struct timespec *) tp; 201 } */ *uap = v; 202 int error; 203 204 if ((error = suser(p->p_ucred, &p->p_acflag)) != 0) 205 return (error); 206 207 return (clock_settime1(SCARG(uap, clock_id), SCARG(uap, tp))); 208 } 209 210 211 int 212 clock_settime1(clock_id, tp) 213 clockid_t clock_id; 214 const struct timespec *tp; 215 { 216 struct timespec ats; 217 struct timeval atv; 218 int error; 219 220 if ((error = copyin(tp, &ats, sizeof(ats))) != 0) 221 return (error); 222 223 switch (clock_id) { 224 case CLOCK_REALTIME: 225 TIMESPEC_TO_TIMEVAL(&atv, &ats); 226 if ((error = settime(&atv)) != 0) 227 return (error); 228 break; 229 case CLOCK_MONOTONIC: 230 return (EINVAL); /* read-only clock */ 231 default: 232 return (EINVAL); 233 } 234 235 return 0; 236 } 237 238 int 239 sys_clock_getres(p, v, retval) 240 struct proc *p; 241 void *v; 242 register_t *retval; 243 { 244 struct sys_clock_getres_args /* { 245 syscallarg(clockid_t) clock_id; 246 syscallarg(struct timespec *) tp; 247 } */ *uap = v; 248 clockid_t clock_id; 249 struct timespec ts; 250 int error = 0; 251 252 clock_id = SCARG(uap, clock_id); 253 switch (clock_id) { 254 case CLOCK_REALTIME: 255 case CLOCK_MONOTONIC: 256 ts.tv_sec = 0; 257 ts.tv_nsec = 1000000000 / hz; 258 break; 259 default: 260 return (EINVAL); 261 } 262 263 if (SCARG(uap, tp)) 264 error = copyout(&ts, SCARG(uap, tp), sizeof(ts)); 265 266 return error; 267 } 268 269 /* ARGSUSED */ 270 int 271 sys_nanosleep(p, v, retval) 272 struct proc *p; 273 void *v; 274 register_t *retval; 275 { 276 static int nanowait; 277 struct sys_nanosleep_args/* { 278 syscallarg(struct timespec *) rqtp; 279 syscallarg(struct timespec *) rmtp; 280 } */ *uap = v; 281 struct timespec rqt; 282 struct timespec rmt; 283 struct timeval atv, utv; 284 int error, s, timo; 285 286 error = copyin((caddr_t)SCARG(uap, rqtp), (caddr_t)&rqt, 287 sizeof(struct timespec)); 288 if (error) 289 return (error); 290 291 TIMESPEC_TO_TIMEVAL(&atv,&rqt) 292 if (itimerfix(&atv) || atv.tv_sec > 1000000000) 293 return (EINVAL); 294 295 s = splclock(); 296 timeradd(&atv,&time,&atv); 297 timo = hzto(&atv); 298 /* 299 * Avoid inadvertantly sleeping forever 300 */ 301 if (timo == 0) 302 timo = 1; 303 splx(s); 304 305 error = tsleep(&nanowait, PWAIT | PCATCH, "nanosleep", timo); 306 if (error == ERESTART) 307 error = EINTR; 308 if (error == EWOULDBLOCK) 309 error = 0; 310 311 if (SCARG(uap, rmtp)) { 312 int error; 313 314 s = splclock(); 315 utv = time; 316 splx(s); 317 318 timersub(&atv, &utv, &utv); 319 if (utv.tv_sec < 0) 320 timerclear(&utv); 321 322 TIMEVAL_TO_TIMESPEC(&utv,&rmt); 323 error = copyout((caddr_t)&rmt, (caddr_t)SCARG(uap,rmtp), 324 sizeof(rmt)); 325 if (error) 326 return (error); 327 } 328 329 return error; 330 } 331 332 /* ARGSUSED */ 333 int 334 sys_gettimeofday(p, v, retval) 335 struct proc *p; 336 void *v; 337 register_t *retval; 338 { 339 struct sys_gettimeofday_args /* { 340 syscallarg(struct timeval *) tp; 341 syscallarg(struct timezone *) tzp; 342 } */ *uap = v; 343 struct timeval atv; 344 int error = 0; 345 struct timezone tzfake; 346 347 if (SCARG(uap, tp)) { 348 microtime(&atv); 349 error = copyout(&atv, SCARG(uap, tp), sizeof(atv)); 350 if (error) 351 return (error); 352 } 353 if (SCARG(uap, tzp)) { 354 /* 355 * NetBSD has no kernel notion of time zone, so we just 356 * fake up a timezone struct and return it if demanded. 357 */ 358 tzfake.tz_minuteswest = 0; 359 tzfake.tz_dsttime = 0; 360 error = copyout(&tzfake, SCARG(uap, tzp), sizeof(tzfake)); 361 } 362 return (error); 363 } 364 365 /* ARGSUSED */ 366 int 367 sys_settimeofday(p, v, retval) 368 struct proc *p; 369 void *v; 370 register_t *retval; 371 { 372 struct sys_settimeofday_args /* { 373 syscallarg(const struct timeval *) tv; 374 syscallarg(const struct timezone *) tzp; 375 } */ *uap = v; 376 int error; 377 378 if ((error = suser(p->p_ucred, &p->p_acflag)) != 0) 379 return (error); 380 381 return settimeofday1(SCARG(uap, tv), SCARG(uap, tzp), p); 382 } 383 384 int 385 settimeofday1(utv, utzp, p) 386 const struct timeval *utv; 387 const struct timezone *utzp; 388 struct proc *p; 389 { 390 struct timeval atv; 391 struct timezone atz; 392 struct timeval *tv = NULL; 393 struct timezone *tzp = NULL; 394 int error; 395 396 /* Verify all parameters before changing time. */ 397 if (utv) { 398 if ((error = copyin(utv, &atv, sizeof(atv))) != 0) 399 return (error); 400 tv = &atv; 401 } 402 /* XXX since we don't use tz, probably no point in doing copyin. */ 403 if (utzp) { 404 if ((error = copyin(utzp, &atz, sizeof(atz))) != 0) 405 return (error); 406 tzp = &atz; 407 } 408 409 if (tv) 410 if ((error = settime(tv)) != 0) 411 return (error); 412 /* 413 * NetBSD has no kernel notion of time zone, and only an 414 * obsolete program would try to set it, so we log a warning. 415 */ 416 if (tzp) 417 log(LOG_WARNING, "pid %d attempted to set the " 418 "(obsolete) kernel time zone\n", p->p_pid); 419 return (0); 420 } 421 422 int tickdelta; /* current clock skew, us. per tick */ 423 long timedelta; /* unapplied time correction, us. */ 424 long bigadj = 1000000; /* use 10x skew above bigadj us. */ 425 426 /* ARGSUSED */ 427 int 428 sys_adjtime(p, v, retval) 429 struct proc *p; 430 void *v; 431 register_t *retval; 432 { 433 struct sys_adjtime_args /* { 434 syscallarg(const struct timeval *) delta; 435 syscallarg(struct timeval *) olddelta; 436 } */ *uap = v; 437 int error; 438 439 if ((error = suser(p->p_ucred, &p->p_acflag)) != 0) 440 return (error); 441 442 return adjtime1(SCARG(uap, delta), SCARG(uap, olddelta), p); 443 } 444 445 int 446 adjtime1(delta, olddelta, p) 447 const struct timeval *delta; 448 struct timeval *olddelta; 449 struct proc *p; 450 { 451 struct timeval atv; 452 long ndelta, ntickdelta, odelta; 453 int error; 454 int s; 455 456 error = copyin(delta, &atv, sizeof(struct timeval)); 457 if (error) 458 return (error); 459 460 if (olddelta != NULL) { 461 if (uvm_useracc((caddr_t)olddelta, 462 sizeof(struct timeval), B_WRITE) == FALSE) 463 return (EFAULT); 464 } 465 466 /* 467 * Compute the total correction and the rate at which to apply it. 468 * Round the adjustment down to a whole multiple of the per-tick 469 * delta, so that after some number of incremental changes in 470 * hardclock(), tickdelta will become zero, lest the correction 471 * overshoot and start taking us away from the desired final time. 472 */ 473 ndelta = atv.tv_sec * 1000000 + atv.tv_usec; 474 if (ndelta > bigadj || ndelta < -bigadj) 475 ntickdelta = 10 * tickadj; 476 else 477 ntickdelta = tickadj; 478 if (ndelta % ntickdelta) 479 ndelta = ndelta / ntickdelta * ntickdelta; 480 481 /* 482 * To make hardclock()'s job easier, make the per-tick delta negative 483 * if we want time to run slower; then hardclock can simply compute 484 * tick + tickdelta, and subtract tickdelta from timedelta. 485 */ 486 if (ndelta < 0) 487 ntickdelta = -ntickdelta; 488 s = splclock(); 489 odelta = timedelta; 490 timedelta = ndelta; 491 tickdelta = ntickdelta; 492 splx(s); 493 494 if (olddelta) { 495 atv.tv_sec = odelta / 1000000; 496 atv.tv_usec = odelta % 1000000; 497 (void) copyout(&atv, olddelta, sizeof(struct timeval)); 498 } 499 return (0); 500 } 501 502 /* 503 * Get value of an interval timer. The process virtual and 504 * profiling virtual time timers are kept in the p_stats area, since 505 * they can be swapped out. These are kept internally in the 506 * way they are specified externally: in time until they expire. 507 * 508 * The real time interval timer is kept in the process table slot 509 * for the process, and its value (it_value) is kept as an 510 * absolute time rather than as a delta, so that it is easy to keep 511 * periodic real-time signals from drifting. 512 * 513 * Virtual time timers are processed in the hardclock() routine of 514 * kern_clock.c. The real time timer is processed by a timeout 515 * routine, called from the softclock() routine. Since a callout 516 * may be delayed in real time due to interrupt processing in the system, 517 * it is possible for the real time timeout routine (realitexpire, given below), 518 * to be delayed in real time past when it is supposed to occur. It 519 * does not suffice, therefore, to reload the real timer .it_value from the 520 * real time timers .it_interval. Rather, we compute the next time in 521 * absolute time the timer should go off. 522 */ 523 /* ARGSUSED */ 524 int 525 sys_getitimer(p, v, retval) 526 struct proc *p; 527 void *v; 528 register_t *retval; 529 { 530 struct sys_getitimer_args /* { 531 syscallarg(int) which; 532 syscallarg(struct itimerval *) itv; 533 } */ *uap = v; 534 int which = SCARG(uap, which); 535 struct itimerval aitv; 536 int s; 537 538 if ((u_int)which > ITIMER_PROF) 539 return (EINVAL); 540 s = splclock(); 541 if (which == ITIMER_REAL) { 542 /* 543 * Convert from absolute to relative time in .it_value 544 * part of real time timer. If time for real time timer 545 * has passed return 0, else return difference between 546 * current time and time for the timer to go off. 547 */ 548 aitv = p->p_realtimer; 549 if (timerisset(&aitv.it_value)) { 550 if (timercmp(&aitv.it_value, &time, <)) 551 timerclear(&aitv.it_value); 552 else 553 timersub(&aitv.it_value, &time, &aitv.it_value); 554 } 555 } else 556 aitv = p->p_stats->p_timer[which]; 557 splx(s); 558 return (copyout(&aitv, SCARG(uap, itv), sizeof(struct itimerval))); 559 } 560 561 /* ARGSUSED */ 562 int 563 sys_setitimer(p, v, retval) 564 struct proc *p; 565 void *v; 566 register_t *retval; 567 { 568 struct sys_setitimer_args /* { 569 syscallarg(int) which; 570 syscallarg(const struct itimerval *) itv; 571 syscallarg(struct itimerval *) oitv; 572 } */ *uap = v; 573 int which = SCARG(uap, which); 574 struct sys_getitimer_args getargs; 575 struct itimerval aitv; 576 const struct itimerval *itvp; 577 int s, error; 578 579 if ((u_int)which > ITIMER_PROF) 580 return (EINVAL); 581 itvp = SCARG(uap, itv); 582 if (itvp && 583 (error = copyin(itvp, &aitv, sizeof(struct itimerval)) != 0)) 584 return (error); 585 if (SCARG(uap, oitv) != NULL) { 586 SCARG(&getargs, which) = which; 587 SCARG(&getargs, itv) = SCARG(uap, oitv); 588 if ((error = sys_getitimer(p, &getargs, retval)) != 0) 589 return (error); 590 } 591 if (itvp == 0) 592 return (0); 593 if (itimerfix(&aitv.it_value) || itimerfix(&aitv.it_interval)) 594 return (EINVAL); 595 s = splclock(); 596 if (which == ITIMER_REAL) { 597 callout_stop(&p->p_realit_ch); 598 if (timerisset(&aitv.it_value)) { 599 /* 600 * Don't need to check hzto() return value, here. 601 * callout_reset() does it for us. 602 */ 603 timeradd(&aitv.it_value, &time, &aitv.it_value); 604 callout_reset(&p->p_realit_ch, hzto(&aitv.it_value), 605 realitexpire, p); 606 } 607 p->p_realtimer = aitv; 608 } else 609 p->p_stats->p_timer[which] = aitv; 610 splx(s); 611 return (0); 612 } 613 614 /* 615 * Real interval timer expired: 616 * send process whose timer expired an alarm signal. 617 * If time is not set up to reload, then just return. 618 * Else compute next time timer should go off which is > current time. 619 * This is where delay in processing this timeout causes multiple 620 * SIGALRM calls to be compressed into one. 621 */ 622 void 623 realitexpire(arg) 624 void *arg; 625 { 626 struct proc *p; 627 int s; 628 629 p = (struct proc *)arg; 630 psignal(p, SIGALRM); 631 if (!timerisset(&p->p_realtimer.it_interval)) { 632 timerclear(&p->p_realtimer.it_value); 633 return; 634 } 635 for (;;) { 636 s = splclock(); 637 timeradd(&p->p_realtimer.it_value, 638 &p->p_realtimer.it_interval, &p->p_realtimer.it_value); 639 if (timercmp(&p->p_realtimer.it_value, &time, >)) { 640 /* 641 * Don't need to check hzto() return value, here. 642 * callout_reset() does it for us. 643 */ 644 callout_reset(&p->p_realit_ch, 645 hzto(&p->p_realtimer.it_value), realitexpire, p); 646 splx(s); 647 return; 648 } 649 splx(s); 650 } 651 } 652 653 /* 654 * Check that a proposed value to load into the .it_value or 655 * .it_interval part of an interval timer is acceptable, and 656 * fix it to have at least minimal value (i.e. if it is less 657 * than the resolution of the clock, round it up.) 658 */ 659 int 660 itimerfix(tv) 661 struct timeval *tv; 662 { 663 664 if (tv->tv_sec < 0 || tv->tv_usec < 0 || tv->tv_usec >= 1000000) 665 return (EINVAL); 666 if (tv->tv_sec == 0 && tv->tv_usec != 0 && tv->tv_usec < tick) 667 tv->tv_usec = tick; 668 return (0); 669 } 670 671 /* 672 * Decrement an interval timer by a specified number 673 * of microseconds, which must be less than a second, 674 * i.e. < 1000000. If the timer expires, then reload 675 * it. In this case, carry over (usec - old value) to 676 * reduce the value reloaded into the timer so that 677 * the timer does not drift. This routine assumes 678 * that it is called in a context where the timers 679 * on which it is operating cannot change in value. 680 */ 681 int 682 itimerdecr(itp, usec) 683 struct itimerval *itp; 684 int usec; 685 { 686 687 if (itp->it_value.tv_usec < usec) { 688 if (itp->it_value.tv_sec == 0) { 689 /* expired, and already in next interval */ 690 usec -= itp->it_value.tv_usec; 691 goto expire; 692 } 693 itp->it_value.tv_usec += 1000000; 694 itp->it_value.tv_sec--; 695 } 696 itp->it_value.tv_usec -= usec; 697 usec = 0; 698 if (timerisset(&itp->it_value)) 699 return (1); 700 /* expired, exactly at end of interval */ 701 expire: 702 if (timerisset(&itp->it_interval)) { 703 itp->it_value = itp->it_interval; 704 itp->it_value.tv_usec -= usec; 705 if (itp->it_value.tv_usec < 0) { 706 itp->it_value.tv_usec += 1000000; 707 itp->it_value.tv_sec--; 708 } 709 } else 710 itp->it_value.tv_usec = 0; /* sec is already 0 */ 711 return (0); 712 } 713 714 /* 715 * ratecheck(): simple time-based rate-limit checking. see ratecheck(9) 716 * for usage and rationale. 717 */ 718 int 719 ratecheck(lasttime, mininterval) 720 struct timeval *lasttime; 721 const struct timeval *mininterval; 722 { 723 struct timeval tv, delta; 724 int s, rv = 0; 725 726 s = splclock(); 727 tv = mono_time; 728 splx(s); 729 730 timersub(&tv, lasttime, &delta); 731 732 /* 733 * check for 0,0 is so that the message will be seen at least once, 734 * even if interval is huge. 735 */ 736 if (timercmp(&delta, mininterval, >=) || 737 (lasttime->tv_sec == 0 && lasttime->tv_usec == 0)) { 738 *lasttime = tv; 739 rv = 1; 740 } 741 742 return (rv); 743 } 744 745 /* 746 * ppsratecheck(): packets (or events) per second limitation. 747 */ 748 int 749 ppsratecheck(lasttime, curpps, maxpps) 750 struct timeval *lasttime; 751 int *curpps; 752 int maxpps; /* maximum pps allowed */ 753 { 754 struct timeval tv, delta; 755 int s, rv; 756 757 s = splclock(); 758 tv = mono_time; 759 splx(s); 760 761 timersub(&tv, lasttime, &delta); 762 763 /* 764 * check for 0,0 is so that the message will be seen at least once. 765 * if more than one second have passed since the last update of 766 * lasttime, reset the counter. 767 * 768 * we do increment *curpps even in *curpps < maxpps case, as some may 769 * try to use *curpps for stat purposes as well. 770 */ 771 if ((lasttime->tv_sec == 0 && lasttime->tv_usec == 0) || 772 delta.tv_sec >= 1) { 773 *lasttime = tv; 774 *curpps = 0; 775 rv = 1; 776 } else if (maxpps < 0) 777 rv = 1; 778 else if (*curpps < maxpps) 779 rv = 1; 780 else 781 rv = 0; 782 783 #if 1 /*DIAGNOSTIC?*/ 784 /* be careful about wrap-around */ 785 if (*curpps + 1 > *curpps) 786 *curpps = *curpps + 1; 787 #else 788 /* 789 * assume that there's not too many calls to this function. 790 * not sure if the assumption holds, as it depends on *caller's* 791 * behavior, not the behavior of this function. 792 * IMHO it is wrong to make assumption on the caller's behavior, 793 * so the above #if is #if 1, not #ifdef DIAGNOSTIC. 794 */ 795 *curpps = *curpps + 1; 796 #endif 797 798 return (rv); 799 } 800