ntp_timer.c revision 362716
1/* 2 * ntp_timer.c - event timer support routines 3 */ 4#ifdef HAVE_CONFIG_H 5# include <config.h> 6#endif 7 8#include "ntp_machine.h" 9#include "ntpd.h" 10#include "ntp_stdlib.h" 11#include "ntp_calendar.h" 12#include "ntp_leapsec.h" 13 14#if defined(HAVE_IO_COMPLETION_PORT) 15# include "ntp_iocompletionport.h" 16# include "ntp_timer.h" 17#endif 18 19#include <stdio.h> 20#include <signal.h> 21#ifdef HAVE_SYS_SIGNAL_H 22# include <sys/signal.h> 23#endif 24#ifdef HAVE_UNISTD_H 25# include <unistd.h> 26#endif 27 28#ifdef KERNEL_PLL 29#include "ntp_syscall.h" 30#endif /* KERNEL_PLL */ 31 32#ifdef AUTOKEY 33#include <openssl/rand.h> 34#endif /* AUTOKEY */ 35 36 37/* TC_ERR represents the timer_create() error return value. */ 38#ifdef SYS_VXWORKS 39#define TC_ERR ERROR 40#else 41#define TC_ERR (-1) 42#endif 43 44 45static void check_leapsec(u_int32, const time_t*, int/*BOOL*/); 46 47/* 48 * These routines provide support for the event timer. The timer is 49 * implemented by an interrupt routine which sets a flag once every 50 * second, and a timer routine which is called when the mainline code 51 * gets around to seeing the flag. The timer routine dispatches the 52 * clock adjustment code if its time has come, then searches the timer 53 * queue for expiries which are dispatched to the transmit procedure. 54 * Finally, we call the hourly procedure to do cleanup and print a 55 * message. 56 */ 57volatile int interface_interval; /* init_io() sets def. 300s */ 58 59/* 60 * Initializing flag. All async routines watch this and only do their 61 * thing when it is clear. 62 */ 63int initializing; 64 65/* 66 * Alarm flag. The mainline code imports this. 67 */ 68volatile int alarm_flag; 69 70/* 71 * The counters and timeouts 72 */ 73static u_long interface_timer; /* interface update timer */ 74static u_long adjust_timer; /* second timer */ 75static u_long stats_timer; /* stats timer */ 76static u_long leapf_timer; /* Report leapfile problems once/day */ 77static u_long huffpuff_timer; /* huff-n'-puff timer */ 78static u_long worker_idle_timer;/* next check for idle intres */ 79u_long leapsec; /* seconds to next leap (proximity class) */ 80int leapdif; /* TAI difference step at next leap second*/ 81u_long orphwait; /* orphan wait time */ 82#ifdef AUTOKEY 83static u_long revoke_timer; /* keys revoke timer */ 84static u_long keys_timer; /* session key timer */ 85u_char sys_revoke = KEY_REVOKE; /* keys revoke timeout (log2 s) */ 86u_char sys_automax = NTP_AUTOMAX; /* key list timeout (log2 s) */ 87#endif /* AUTOKEY */ 88 89/* 90 * Statistics counter for the interested. 91 */ 92volatile u_long alarm_overflow; 93 94u_long current_time; /* seconds since startup */ 95 96/* 97 * Stats. Number of overflows and number of calls to transmit(). 98 */ 99u_long timer_timereset; 100u_long timer_overflows; 101u_long timer_xmtcalls; 102 103#if defined(VMS) 104static int vmstimer[2]; /* time for next timer AST */ 105static int vmsinc[2]; /* timer increment */ 106#endif /* VMS */ 107 108#ifdef SYS_WINNT 109HANDLE WaitableTimerHandle; 110#else 111static RETSIGTYPE alarming (int); 112#endif /* SYS_WINNT */ 113 114#if !defined(VMS) 115# if !defined SYS_WINNT || defined(SYS_CYGWIN32) 116# ifdef HAVE_TIMER_CREATE 117static timer_t timer_id; 118typedef struct itimerspec intervaltimer; 119# define itv_frac tv_nsec 120# else 121typedef struct itimerval intervaltimer; 122# define itv_frac tv_usec 123# endif 124intervaltimer itimer; 125# endif 126#endif 127 128#if !defined(SYS_WINNT) && !defined(VMS) 129void set_timer_or_die(const intervaltimer *); 130#endif 131 132 133#if !defined(SYS_WINNT) && !defined(VMS) 134void 135set_timer_or_die( 136 const intervaltimer * ptimer 137 ) 138{ 139 const char * setfunc; 140 int rc; 141 142# ifdef HAVE_TIMER_CREATE 143 setfunc = "timer_settime"; 144 rc = timer_settime(timer_id, 0, &itimer, NULL); 145# else 146 setfunc = "setitimer"; 147 rc = setitimer(ITIMER_REAL, &itimer, NULL); 148# endif 149 if (-1 == rc) { 150 msyslog(LOG_ERR, "interval timer %s failed, %m", 151 setfunc); 152 exit(1); 153 } 154} 155#endif /* !SYS_WINNT && !VMS */ 156 157 158/* 159 * reinit_timer - reinitialize interval timer after a clock step. 160 */ 161void 162reinit_timer(void) 163{ 164#if !defined(SYS_WINNT) && !defined(VMS) 165 ZERO(itimer); 166# ifdef HAVE_TIMER_CREATE 167 timer_gettime(timer_id, &itimer); 168# else 169 getitimer(ITIMER_REAL, &itimer); 170# endif 171 if (itimer.it_value.tv_sec < 0 || 172 itimer.it_value.tv_sec > (1 << EVENT_TIMEOUT)) 173 itimer.it_value.tv_sec = (1 << EVENT_TIMEOUT); 174 if (itimer.it_value.itv_frac < 0) 175 itimer.it_value.itv_frac = 0; 176 if (0 == itimer.it_value.tv_sec && 177 0 == itimer.it_value.itv_frac) 178 itimer.it_value.tv_sec = (1 << EVENT_TIMEOUT); 179 itimer.it_interval.tv_sec = (1 << EVENT_TIMEOUT); 180 itimer.it_interval.itv_frac = 0; 181 set_timer_or_die(&itimer); 182# endif /* VMS */ 183} 184 185 186/* 187 * init_timer - initialize the timer data structures 188 */ 189void 190init_timer(void) 191{ 192 /* 193 * Initialize... 194 */ 195 alarm_flag = FALSE; 196 alarm_overflow = 0; 197 adjust_timer = 1; 198 stats_timer = SECSPERHR; 199 leapf_timer = SECSPERDAY; 200 huffpuff_timer = 0; 201 interface_timer = 0; 202 current_time = 0; 203 timer_overflows = 0; 204 timer_xmtcalls = 0; 205 timer_timereset = 0; 206 207#ifndef SYS_WINNT 208 /* 209 * Set up the alarm interrupt. The first comes 2**EVENT_TIMEOUT 210 * seconds from now and they continue on every 2**EVENT_TIMEOUT 211 * seconds. 212 */ 213# ifndef VMS 214# ifdef HAVE_TIMER_CREATE 215 if (TC_ERR == timer_create(CLOCK_REALTIME, NULL, &timer_id)) { 216 msyslog(LOG_ERR, "timer_create failed, %m"); 217 exit(1); 218 } 219# endif 220 signal_no_reset(SIGALRM, alarming); 221 itimer.it_interval.tv_sec = 222 itimer.it_value.tv_sec = (1 << EVENT_TIMEOUT); 223 itimer.it_interval.itv_frac = itimer.it_value.itv_frac = 0; 224 set_timer_or_die(&itimer); 225# else /* VMS follows */ 226 vmsinc[0] = 10000000; /* 1 sec */ 227 vmsinc[1] = 0; 228 lib$emul(&(1<<EVENT_TIMEOUT), &vmsinc, &0, &vmsinc); 229 230 sys$gettim(&vmstimer); /* that's "now" as abstime */ 231 232 lib$addx(&vmsinc, &vmstimer, &vmstimer); 233 sys$setimr(0, &vmstimer, alarming, alarming, 0); 234# endif /* VMS */ 235#else /* SYS_WINNT follows */ 236 /* 237 * Set up timer interrupts for every 2**EVENT_TIMEOUT seconds 238 * Under Windows/NT, 239 */ 240 241 WaitableTimerHandle = CreateWaitableTimer(NULL, FALSE, NULL); 242 if (WaitableTimerHandle == NULL) { 243 msyslog(LOG_ERR, "CreateWaitableTimer failed: %m"); 244 exit(1); 245 } 246 else { 247 DWORD Period; 248 LARGE_INTEGER DueTime; 249 BOOL rc; 250 251 Period = (1 << EVENT_TIMEOUT) * 1000; 252 DueTime.QuadPart = Period * 10000i64; 253 rc = SetWaitableTimer(WaitableTimerHandle, &DueTime, 254 Period, NULL, NULL, FALSE); 255 if (!rc) { 256 msyslog(LOG_ERR, "SetWaitableTimer failed: %m"); 257 exit(1); 258 } 259 } 260 261#endif /* SYS_WINNT */ 262} 263 264 265/* 266 * intres_timeout_req(s) is invoked in the parent to schedule an idle 267 * timeout to fire in s seconds, if not reset earlier by a call to 268 * intres_timeout_req(0), which clears any pending timeout. When the 269 * timeout expires, worker_idle_timer_fired() is invoked (again, in the 270 * parent). 271 * 272 * sntp and ntpd each provide implementations adapted to their timers. 273 */ 274void 275intres_timeout_req( 276 u_int seconds /* 0 cancels */ 277 ) 278{ 279#if defined(HAVE_DROPROOT) && defined(NEED_EARLY_FORK) 280 if (droproot) { 281 worker_idle_timer = 0; 282 return; 283 } 284#endif 285 if (0 == seconds) { 286 worker_idle_timer = 0; 287 return; 288 } 289 worker_idle_timer = current_time + seconds; 290} 291 292 293/* 294 * timer - event timer 295 */ 296void 297timer(void) 298{ 299 struct peer * p; 300 struct peer * next_peer; 301 l_fp now; 302 time_t tnow; 303 304 /* 305 * The basic timerevent is one second. This is used to adjust the 306 * system clock in time and frequency, implement the kiss-o'-death 307 * function and the association polling function. 308 */ 309 current_time++; 310 if (adjust_timer <= current_time) { 311 adjust_timer += 1; 312 adj_host_clock(); 313#ifdef REFCLOCK 314 for (p = peer_list; p != NULL; p = next_peer) { 315 next_peer = p->p_link; 316 if (FLAG_REFCLOCK & p->flags) 317 refclock_timer(p); 318 } 319#endif /* REFCLOCK */ 320 } 321 322 /* 323 * Now dispatch any peers whose event timer has expired. Be 324 * careful here, since the peer structure might go away as the 325 * result of the call. 326 */ 327 for (p = peer_list; p != NULL; p = next_peer) { 328 next_peer = p->p_link; 329 330 /* 331 * Restrain the non-burst packet rate not more 332 * than one packet every 16 seconds. This is 333 * usually tripped using iburst and minpoll of 334 * 128 s or less. 335 */ 336 if (p->throttle > 0) 337 p->throttle--; 338 if (p->nextdate <= current_time) { 339#ifdef REFCLOCK 340 if (FLAG_REFCLOCK & p->flags) 341 refclock_transmit(p); 342 else 343#endif /* REFCLOCK */ 344 transmit(p); 345 } 346 } 347 348 /* 349 * Orphan mode is active when enabled and when no servers less 350 * than the orphan stratum are available. A server with no other 351 * synchronization source is an orphan. It shows offset zero and 352 * reference ID the loopback address. 353 * 354 * [bug 3644] If the orphan stratum is >= STRATUM_UNSPEC, we 355 * have to do it a bit different. 'clock_select()' simply 356 * tiptoed home, but since we're unsync'd and have no peer, we 357 * should eventually declare we're out of sync. Otherwise we 358 * would persistently claim we're good, and we're everything but 359 * that... 360 * 361 * XXX: do we want to log an event about this? 362 */ 363 if (sys_peer == NULL && current_time > orphwait) { 364 if (sys_orphan < STRATUM_UNSPEC) { 365 if (sys_leap == LEAP_NOTINSYNC) { 366 set_sys_leap(LEAP_NOWARNING); 367#ifdef AUTOKEY 368 if (crypto_flags) 369 crypto_update(); 370#endif /* AUTOKEY */ 371 } 372 sys_stratum = (u_char)sys_orphan; 373 } else { 374 if (sys_leap != LEAP_NOTINSYNC) { 375 set_sys_leap(LEAP_NOTINSYNC); 376 msyslog(LOG_WARNING, "%s", 377 "no peer for too long, server running free now"); 378 } 379 sys_stratum = STRATUM_UNSPEC; 380 } 381 if (sys_stratum > 1) 382 sys_refid = htonl(LOOPBACKADR); 383 else 384 memcpy(&sys_refid, "LOOP", 4); 385 sys_offset = 0; 386 sys_rootdelay = 0; 387 sys_rootdisp = 0; 388 } 389 390 get_systime(&now); 391 time(&tnow); 392 393 /* 394 * Leapseconds. Get time and defer to worker if either something 395 * is imminent or every 8th second. 396 */ 397 if (leapsec > LSPROX_NOWARN || 0 == (current_time & 7)) 398 check_leapsec(now.l_ui, &tnow, 399 (sys_leap == LEAP_NOTINSYNC)); 400 if (sys_leap != LEAP_NOTINSYNC) { 401 if (leapsec >= LSPROX_ANNOUNCE && leapdif) { 402 if (leapdif > 0) 403 set_sys_leap(LEAP_ADDSECOND); 404 else 405 set_sys_leap(LEAP_DELSECOND); 406 } else { 407 set_sys_leap(LEAP_NOWARNING); 408 } 409 } 410 411 /* 412 * Update huff-n'-puff filter. 413 */ 414 if (huffpuff_timer <= current_time) { 415 huffpuff_timer += HUFFPUFF; 416 huffpuff(); 417 } 418 419#ifdef AUTOKEY 420 /* 421 * Garbage collect expired keys. 422 */ 423 if (keys_timer <= current_time) { 424 keys_timer += (1UL << sys_automax); 425 auth_agekeys(); 426 } 427 428 /* 429 * Generate new private value. This causes all associations 430 * to regenerate cookies. 431 */ 432 if (revoke_timer && revoke_timer <= current_time) { 433 revoke_timer += (1UL << sys_revoke); 434 RAND_bytes((u_char *)&sys_private, 4); 435 } 436#endif /* AUTOKEY */ 437 438 /* 439 * Interface update timer 440 */ 441 if (interface_interval && interface_timer <= current_time) { 442 timer_interfacetimeout(current_time + 443 interface_interval); 444 DPRINTF(2, ("timer: interface update\n")); 445 interface_update(NULL, NULL); 446 } 447 448 if (worker_idle_timer && worker_idle_timer <= current_time) 449 worker_idle_timer_fired(); 450 451 /* 452 * Finally, write hourly stats and do the hourly 453 * and daily leapfile checks. 454 */ 455 if (stats_timer <= current_time) { 456 stats_timer += SECSPERHR; 457 write_stats(); 458 if (leapf_timer <= current_time) { 459 leapf_timer += SECSPERDAY; 460 check_leap_file(TRUE, now.l_ui, &tnow); 461 } else { 462 check_leap_file(FALSE, now.l_ui, &tnow); 463 } 464 } 465} 466 467 468#ifndef SYS_WINNT 469/* 470 * alarming - tell the world we've been alarmed 471 */ 472static RETSIGTYPE 473alarming( 474 int sig 475 ) 476{ 477# ifdef DEBUG 478 const char *msg = "alarming: initializing TRUE\n"; 479# endif 480 481 if (!initializing) { 482 if (alarm_flag) { 483 alarm_overflow++; 484# ifdef DEBUG 485 msg = "alarming: overflow\n"; 486# endif 487 } else { 488# ifndef VMS 489 alarm_flag++; 490# else 491 /* VMS AST routine, increment is no good */ 492 alarm_flag = 1; 493# endif 494# ifdef DEBUG 495 msg = "alarming: normal\n"; 496# endif 497 } 498 } 499# ifdef VMS 500 lib$addx(&vmsinc, &vmstimer, &vmstimer); 501 sys$setimr(0, &vmstimer, alarming, alarming, 0); 502# endif 503# ifdef DEBUG 504 if (debug >= 4) 505 (void)(-1 == write(1, msg, strlen(msg))); 506# endif 507} 508#endif /* SYS_WINNT */ 509 510 511void 512timer_interfacetimeout(u_long timeout) 513{ 514 interface_timer = timeout; 515} 516 517 518/* 519 * timer_clr_stats - clear timer module stat counters 520 */ 521void 522timer_clr_stats(void) 523{ 524 timer_overflows = 0; 525 timer_xmtcalls = 0; 526 timer_timereset = current_time; 527} 528 529 530static void 531check_leap_sec_in_progress( const leap_result_t *lsdata ) { 532 int prv_leap_sec_in_progress = leap_sec_in_progress; 533 leap_sec_in_progress = lsdata->tai_diff && (lsdata->ddist < 3); 534 535 /* if changed we may have to update the leap status sent to clients */ 536 if (leap_sec_in_progress != prv_leap_sec_in_progress) 537 set_sys_leap(sys_leap); 538} 539 540 541static void 542check_leapsec( 543 u_int32 now , 544 const time_t * tpiv , 545 int/*BOOL*/ reset) 546{ 547 static const char leapmsg_p_step[] = 548 "Positive leap second, stepped backward."; 549 static const char leapmsg_p_slew[] = 550 "Positive leap second, no step correction. " 551 "System clock will be inaccurate for a long time."; 552 553 static const char leapmsg_n_step[] = 554 "Negative leap second, stepped forward."; 555 static const char leapmsg_n_slew[] = 556 "Negative leap second, no step correction. " 557 "System clock will be inaccurate for a long time."; 558 559 leap_result_t lsdata; 560 u_int32 lsprox; 561#ifdef AUTOKEY 562 int/*BOOL*/ update_autokey = FALSE; 563#endif 564 565#ifndef SYS_WINNT /* WinNT port has its own leap second handling */ 566# ifdef KERNEL_PLL 567 leapsec_electric(pll_control && kern_enable); 568# else 569 leapsec_electric(0); 570# endif 571#endif 572#ifdef LEAP_SMEAR 573 leap_smear.enabled = leap_smear_intv != 0; 574#endif 575 if (reset) { 576 lsprox = LSPROX_NOWARN; 577 leapsec_reset_frame(); 578 memset(&lsdata, 0, sizeof(lsdata)); 579 } else { 580 int fired; 581 582 fired = leapsec_query(&lsdata, now, tpiv); 583 584 DPRINTF(3, ("*** leapsec_query: fired %i, now %u (0x%08X), tai_diff %i, ddist %u\n", 585 fired, now, now, lsdata.tai_diff, lsdata.ddist)); 586 587#ifdef LEAP_SMEAR 588 leap_smear.in_progress = 0; 589 leap_smear.doffset = 0.0; 590 591 if (leap_smear.enabled) { 592 if (lsdata.tai_diff) { 593 if (leap_smear.interval == 0) { 594 leap_smear.interval = leap_smear_intv; 595 leap_smear.intv_end = lsdata.ttime.Q_s; 596 leap_smear.intv_start = leap_smear.intv_end - leap_smear.interval; 597 DPRINTF(1, ("*** leapsec_query: setting leap_smear interval %li, begin %.0f, end %.0f\n", 598 leap_smear.interval, leap_smear.intv_start, leap_smear.intv_end)); 599 } 600 } else { 601 if (leap_smear.interval) 602 DPRINTF(1, ("*** leapsec_query: clearing leap_smear interval\n")); 603 leap_smear.interval = 0; 604 } 605 606 if (leap_smear.interval) { 607 double dtemp = now; 608 if (dtemp >= leap_smear.intv_start && dtemp <= leap_smear.intv_end) { 609 double leap_smear_time = dtemp - leap_smear.intv_start; 610 /* 611 * For now we just do a linear interpolation over the smear interval 612 */ 613#if 0 614 // linear interpolation 615 leap_smear.doffset = -(leap_smear_time * lsdata.tai_diff / leap_smear.interval); 616#else 617 // Google approach: lie(t) = (1.0 - cos(pi * t / w)) / 2.0 618 leap_smear.doffset = -((double) lsdata.tai_diff - cos( M_PI * leap_smear_time / leap_smear.interval)) / 2.0; 619#endif 620 /* 621 * TODO see if we're inside an inserted leap second, so we need to compute 622 * leap_smear.doffset = 1.0 - leap_smear.doffset 623 */ 624 leap_smear.in_progress = 1; 625#if 0 && defined( DEBUG ) 626 msyslog(LOG_NOTICE, "*** leapsec_query: [%.0f:%.0f] (%li), now %u (%.0f), smear offset %.6f ms\n", 627 leap_smear.intv_start, leap_smear.intv_end, leap_smear.interval, 628 now, leap_smear_time, leap_smear.doffset); 629#else 630 DPRINTF(1, ("*** leapsec_query: [%.0f:%.0f] (%li), now %u (%.0f), smear offset %.6f ms\n", 631 leap_smear.intv_start, leap_smear.intv_end, leap_smear.interval, 632 now, leap_smear_time, leap_smear.doffset)); 633#endif 634 635 } 636 } 637 } 638 else 639 leap_smear.interval = 0; 640 641 /* 642 * Update the current leap smear offset, eventually 0.0 if outside smear interval. 643 */ 644 DTOLFP(leap_smear.doffset, &leap_smear.offset); 645 646#endif /* LEAP_SMEAR */ 647 648 if (fired) { 649 /* Full hit. Eventually step the clock, but always 650 * announce the leap event has happened. 651 */ 652 const char *leapmsg = NULL; 653 double lswarp = lsdata.warped; 654 if (lswarp < 0.0) { 655 if (clock_max_back > 0.0 && 656 clock_max_back < -lswarp) { 657 step_systime(lswarp); 658 leapmsg = leapmsg_p_step; 659 } else { 660 leapmsg = leapmsg_p_slew; 661 } 662 } else if (lswarp > 0.0) { 663 if (clock_max_fwd > 0.0 && 664 clock_max_fwd < lswarp) { 665 step_systime(lswarp); 666 leapmsg = leapmsg_n_step; 667 } else { 668 leapmsg = leapmsg_n_slew; 669 } 670 } 671 if (leapmsg) 672 msyslog(LOG_NOTICE, "%s", leapmsg); 673 report_event(EVNT_LEAP, NULL, NULL); 674#ifdef AUTOKEY 675 update_autokey = TRUE; 676#endif 677 lsprox = LSPROX_NOWARN; 678 leapsec = LSPROX_NOWARN; 679 sys_tai = lsdata.tai_offs; 680 } else { 681#ifdef AUTOKEY 682 update_autokey = (sys_tai != (u_int)lsdata.tai_offs); 683#endif 684 lsprox = lsdata.proximity; 685 sys_tai = lsdata.tai_offs; 686 } 687 } 688 689 /* We guard against panic alarming during the red alert phase. 690 * Strange and evil things might happen if we go from stone cold 691 * to piping hot in one step. If things are already that wobbly, 692 * we let the normal clock correction take over, even if a jump 693 * is involved. 694 * Also make sure the alarming events are edge-triggered, that is, 695 * ceated only when the threshold is crossed. 696 */ 697 if ( (leapsec > 0 || lsprox < LSPROX_ALERT) 698 && leapsec < lsprox ) { 699 if ( leapsec < LSPROX_SCHEDULE 700 && lsprox >= LSPROX_SCHEDULE) { 701 if (lsdata.dynamic) 702 report_event(PEVNT_ARMED, sys_peer, NULL); 703 else 704 report_event(EVNT_ARMED, NULL, NULL); 705 } 706 leapsec = lsprox; 707 } 708 if (leapsec > lsprox) { 709 if ( leapsec >= LSPROX_SCHEDULE 710 && lsprox < LSPROX_SCHEDULE) { 711 report_event(EVNT_DISARMED, NULL, NULL); 712 } 713 leapsec = lsprox; 714 } 715 716 if (leapsec >= LSPROX_SCHEDULE) 717 leapdif = lsdata.tai_diff; 718 else 719 leapdif = 0; 720 721 check_leap_sec_in_progress(&lsdata); 722 723#ifdef AUTOKEY 724 if (update_autokey) 725 crypto_update_taichange(); 726#endif 727} 728