1 /* $NetBSD: refclock_datum.c,v 1.6 2016/01/08 21:35:39 christos Exp $ */ 2 3 /* 4 ** refclock_datum - clock driver for the Datum Programmable Time Server 5 ** 6 ** Important note: This driver assumes that you have termios. If you have 7 ** a system that does not have termios, you will have to modify this driver. 8 ** 9 ** Sorry, I have only tested this driver on SUN and HP platforms. 10 */ 11 12 #ifdef HAVE_CONFIG_H 13 # include <config.h> 14 #endif 15 16 #include "ntp_types.h" 17 18 #if defined(REFCLOCK) && defined(CLOCK_DATUM) 19 20 /* 21 ** Include Files 22 */ 23 24 #include "ntpd.h" 25 #include "ntp_io.h" 26 #include "ntp_tty.h" 27 #include "ntp_refclock.h" 28 #include "timevalops.h" 29 #include "ntp_stdlib.h" 30 31 #include <stdio.h> 32 #include <ctype.h> 33 34 #if defined(STREAM) 35 #include <stropts.h> 36 #endif /* STREAM */ 37 38 #include "ntp_stdlib.h" 39 40 /* 41 ** This driver supports the Datum Programmable Time System (PTS) clock. 42 ** The clock works in very straight forward manner. When it receives a 43 ** time code request (e.g., the ascii string "//k/mn"), it responds with 44 ** a seven byte BCD time code. This clock only responds with a 45 ** time code after it first receives the "//k/mn" message. It does not 46 ** periodically send time codes back at some rate once it is started. 47 ** the returned time code can be broken down into the following fields. 48 ** 49 ** _______________________________ 50 ** Bit Index | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | 51 ** =============================== 52 ** byte 0: | - - - - | H D | 53 ** =============================== 54 ** byte 1: | T D | U D | 55 ** =============================== 56 ** byte 2: | - - | T H | U H | 57 ** =============================== 58 ** byte 3: | - | T M | U M | 59 ** =============================== 60 ** byte 4: | - | T S | U S | 61 ** =============================== 62 ** byte 5: | t S | h S | 63 ** =============================== 64 ** byte 6: | m S | - - - - | 65 ** =============================== 66 ** 67 ** In the table above: 68 ** 69 ** "-" means don't care 70 ** "H D", "T D", and "U D" means Hundreds, Tens, and Units of Days 71 ** "T H", and "UH" means Tens and Units of Hours 72 ** "T M", and "U M" means Tens and Units of Minutes 73 ** "T S", and "U S" means Tens and Units of Seconds 74 ** "t S", "h S", and "m S" means tenths, hundredths, and thousandths 75 ** of seconds 76 ** 77 ** The Datum PTS communicates throught the RS232 port on your machine. 78 ** Right now, it assumes that you have termios. This driver has been tested 79 ** on SUN and HP workstations. The Datum PTS supports various IRIG and 80 ** NASA input codes. This driver assumes that the name of the device is 81 ** /dev/datum. You will need to make a soft link to your RS232 device or 82 ** create a new driver to use this refclock. 83 */ 84 85 /* 86 ** Datum PTS defines 87 */ 88 89 /* 90 ** Note that if GMT is defined, then the Datum PTS must use Greenwich 91 ** time. Otherwise, this driver allows the Datum PTS to use the current 92 ** wall clock for its time. It determines the time zone offset by minimizing 93 ** the error after trying several time zone offsets. If the Datum PTS 94 ** time is Greenwich time and GMT is not defined, everything should still 95 ** work since the time zone will be found to be 0. What this really means 96 ** is that your system time (at least to start with) must be within the 97 ** correct time by less than +- 30 minutes. The default is for GMT to not 98 ** defined. If you really want to force GMT without the funny +- 30 minute 99 ** stuff then you must define (uncomment) GMT below. 100 */ 101 102 /* 103 #define GMT 104 #define DEBUG_DATUM_PTC 105 #define LOG_TIME_ERRORS 106 */ 107 108 109 #define PRECISION (-10) /* precision assumed 1/1024 ms */ 110 #define REFID "DATM" /* reference id */ 111 #define DATUM_DISPERSION 0 /* fixed dispersion = 0 ms */ 112 #define DATUM_MAX_ERROR 0.100 /* limits on sigma squared */ 113 #define DATUM_DEV "/dev/datum" /* device name */ 114 115 #define DATUM_MAX_ERROR2 (DATUM_MAX_ERROR*DATUM_MAX_ERROR) 116 117 /* 118 ** The Datum PTS structure 119 */ 120 121 /* 122 ** I don't use a fixed array of MAXUNITS like everyone else just because 123 ** I don't like to program that way. Sorry if this bothers anyone. I assume 124 ** that you can use any id for your unit and I will search for it in a 125 ** dynamic array of units until I find it. I was worried that users might 126 ** enter a bad id in their configuration file (larger than MAXUNITS) and 127 ** besides, it is just cleaner not to have to assume that you have a fixed 128 ** number of anything in a program. 129 */ 130 131 struct datum_pts_unit { 132 struct peer *peer; /* peer used by ntp */ 133 int PTS_fd; /* file descriptor for PTS */ 134 u_int unit; /* id for unit */ 135 u_long timestarted; /* time started */ 136 l_fp lastrec; /* time tag for the receive time (system) */ 137 l_fp lastref; /* reference time (Datum time) */ 138 u_long yearstart; /* the year that this clock started */ 139 int coderecv; /* number of time codes received */ 140 int day; /* day */ 141 int hour; /* hour */ 142 int minute; /* minutes */ 143 int second; /* seconds */ 144 int msec; /* miliseconds */ 145 int usec; /* miliseconds */ 146 u_char leap; /* funny leap character code */ 147 char retbuf[8]; /* returned time from the datum pts */ 148 char nbytes; /* number of bytes received from datum pts */ 149 double sigma2; /* average squared error (roughly) */ 150 int tzoff; /* time zone offest from GMT */ 151 }; 152 153 /* 154 ** PTS static constant variables for internal use 155 */ 156 157 static char TIME_REQUEST[6]; /* request message sent to datum for time */ 158 static int nunits; /* number of active units */ 159 160 /* 161 ** Callback function prototypes that ntpd needs to know about. 162 */ 163 164 static int datum_pts_start (int, struct peer *); 165 static void datum_pts_shutdown (int, struct peer *); 166 static void datum_pts_poll (int, struct peer *); 167 static void datum_pts_control (int, const struct refclockstat *, 168 struct refclockstat *, struct peer *); 169 static void datum_pts_init (void); 170 static void datum_pts_buginfo (int, struct refclockbug *, struct peer *); 171 172 /* 173 ** This is the call back function structure that ntpd actually uses for 174 ** this refclock. 175 */ 176 177 struct refclock refclock_datum = { 178 datum_pts_start, /* start up a new Datum refclock */ 179 datum_pts_shutdown, /* shutdown a Datum refclock */ 180 datum_pts_poll, /* sends out the time request */ 181 datum_pts_control, /* not used */ 182 datum_pts_init, /* initialization (called first) */ 183 datum_pts_buginfo, /* not used */ 184 NOFLAGS /* we are not setting any special flags */ 185 }; 186 187 /* 188 ** The datum_pts_receive callback function is handled differently from the 189 ** rest. It is passed to the ntpd io data structure. Basically, every 190 ** 64 seconds, the datum_pts_poll() routine is called. It sends out the time 191 ** request message to the Datum Programmable Time System. Then, ntpd 192 ** waits on a select() call to receive data back. The datum_pts_receive() 193 ** function is called as data comes back. We expect a seven byte time 194 ** code to be returned but the datum_pts_receive() function may only get 195 ** a few bytes passed to it at a time. In other words, this routine may 196 ** get called by the io stuff in ntpd a few times before we get all seven 197 ** bytes. Once the last byte is received, we process it and then pass the 198 ** new time measurement to ntpd for updating the system time. For now, 199 ** there is no 3 state filtering done on the time measurements. The 200 ** jitter may be a little high but at least for its current use, it is not 201 ** a problem. We have tried to keep things as simple as possible. This 202 ** clock should not jitter more than 1 or 2 mseconds at the most once 203 ** things settle down. It is important to get the right drift calibrated 204 ** in the ntpd.drift file as well as getting the right tick set up right 205 ** using tickadj for SUNs. Tickadj is not used for the HP but you need to 206 ** remember to bring up the adjtime daemon because HP does not support 207 ** the adjtime() call. 208 */ 209 210 static void datum_pts_receive (struct recvbuf *); 211 212 /*......................................................................*/ 213 /* datum_pts_start - start up the datum PTS. This means open the */ 214 /* RS232 device and set up the data structure for my unit. */ 215 /*......................................................................*/ 216 217 static int 218 datum_pts_start( 219 int unit, 220 struct peer *peer 221 ) 222 { 223 struct refclockproc *pp; 224 struct datum_pts_unit *datum_pts; 225 int fd; 226 #ifdef HAVE_TERMIOS 227 int rc; 228 struct termios arg; 229 #endif 230 231 #ifdef DEBUG_DATUM_PTC 232 if (debug) 233 printf("Starting Datum PTS unit %d\n", unit); 234 #endif 235 236 /* 237 ** Open the Datum PTS device 238 */ 239 fd = open(DATUM_DEV, O_RDWR); 240 241 if (fd < 0) { 242 msyslog(LOG_ERR, "Datum_PTS: open(\"%s\", O_RDWR) failed: %m", DATUM_DEV); 243 return 0; 244 } 245 246 /* 247 ** Create the memory for the new unit 248 */ 249 datum_pts = emalloc_zero(sizeof(*datum_pts)); 250 datum_pts->unit = unit; /* set my unit id */ 251 datum_pts->yearstart = 0; /* initialize the yearstart to 0 */ 252 datum_pts->sigma2 = 0.0; /* initialize the sigma2 to 0 */ 253 254 datum_pts->PTS_fd = fd; 255 256 if (-1 == fcntl(datum_pts->PTS_fd, F_SETFL, 0)) /* clear the descriptor flags */ 257 msyslog(LOG_ERR, "MSF_ARCRON(%d): fcntl(F_SETFL, 0): %m.", 258 unit); 259 260 #ifdef DEBUG_DATUM_PTC 261 if (debug) 262 printf("Opening RS232 port with file descriptor %d\n", 263 datum_pts->PTS_fd); 264 #endif 265 266 /* 267 ** Set up the RS232 terminal device information. Note that we assume that 268 ** we have termios. This code has only been tested on SUNs and HPs. If your 269 ** machine does not have termios this driver cannot be initialized. You can change this 270 ** if you want by editing this source. Please give the changes back to the 271 ** ntp folks so that it can become part of their regular distribution. 272 */ 273 274 memset(&arg, 0, sizeof(arg)); 275 276 arg.c_iflag = IGNBRK; 277 arg.c_oflag = 0; 278 arg.c_cflag = B9600 | CS8 | CREAD | PARENB | CLOCAL; 279 arg.c_lflag = 0; 280 arg.c_cc[VMIN] = 0; /* start timeout timer right away (not used) */ 281 arg.c_cc[VTIME] = 30; /* 3 second timout on reads (not used) */ 282 283 rc = tcsetattr(datum_pts->PTS_fd, TCSANOW, &arg); 284 if (rc < 0) { 285 msyslog(LOG_ERR, "Datum_PTS: tcsetattr(\"%s\") failed: %m", DATUM_DEV); 286 close(datum_pts->PTS_fd); 287 free(datum_pts); 288 return 0; 289 } 290 291 /* 292 ** Initialize the ntpd IO structure 293 */ 294 295 datum_pts->peer = peer; 296 pp = peer->procptr; 297 pp->io.clock_recv = datum_pts_receive; 298 pp->io.srcclock = peer; 299 pp->io.datalen = 0; 300 pp->io.fd = datum_pts->PTS_fd; 301 302 if (!io_addclock(&pp->io)) { 303 pp->io.fd = -1; 304 #ifdef DEBUG_DATUM_PTC 305 if (debug) 306 printf("Problem adding clock\n"); 307 #endif 308 309 msyslog(LOG_ERR, "Datum_PTS: Problem adding clock"); 310 close(datum_pts->PTS_fd); 311 free(datum_pts); 312 313 return 0; 314 } 315 peer->procptr->unitptr = datum_pts; 316 317 /* 318 ** Now add one to the number of units and return a successful code 319 */ 320 321 nunits++; 322 return 1; 323 324 } 325 326 327 /*......................................................................*/ 328 /* datum_pts_shutdown - this routine shuts doen the device and */ 329 /* removes the memory for the unit. */ 330 /*......................................................................*/ 331 332 static void 333 datum_pts_shutdown( 334 int unit, 335 struct peer *peer 336 ) 337 { 338 struct refclockproc *pp; 339 struct datum_pts_unit *datum_pts; 340 341 #ifdef DEBUG_DATUM_PTC 342 if (debug) 343 printf("Shutdown Datum PTS\n"); 344 #endif 345 346 msyslog(LOG_ERR, "Datum_PTS: Shutdown Datum PTS"); 347 348 /* 349 ** We found the unit so close the file descriptor and free up the memory used 350 ** by the structure. 351 */ 352 pp = peer->procptr; 353 datum_pts = pp->unitptr; 354 if (NULL != datum_pts) { 355 io_closeclock(&pp->io); 356 free(datum_pts); 357 } 358 } 359 360 361 /*......................................................................*/ 362 /* datum_pts_poll - this routine sends out the time request to the */ 363 /* Datum PTS device. The time will be passed back in the */ 364 /* datum_pts_receive() routine. */ 365 /*......................................................................*/ 366 367 static void 368 datum_pts_poll( 369 int unit, 370 struct peer *peer 371 ) 372 { 373 int error_code; 374 struct datum_pts_unit *datum_pts; 375 376 datum_pts = peer->procptr->unitptr; 377 378 #ifdef DEBUG_DATUM_PTC 379 if (debug) 380 printf("Poll Datum PTS\n"); 381 #endif 382 383 /* 384 ** Find the right unit and send out a time request once it is found. 385 */ 386 error_code = write(datum_pts->PTS_fd, TIME_REQUEST, 6); 387 if (error_code != 6) 388 perror("TIME_REQUEST"); 389 datum_pts->nbytes = 0; 390 } 391 392 393 /*......................................................................*/ 394 /* datum_pts_control - not used */ 395 /*......................................................................*/ 396 397 static void 398 datum_pts_control( 399 int unit, 400 const struct refclockstat *in, 401 struct refclockstat *out, 402 struct peer *peer 403 ) 404 { 405 406 #ifdef DEBUG_DATUM_PTC 407 if (debug) 408 printf("Control Datum PTS\n"); 409 #endif 410 411 } 412 413 414 /*......................................................................*/ 415 /* datum_pts_init - initializes things for all possible Datum */ 416 /* time code generators that might be used. In practice, this is */ 417 /* only called once at the beginning before anything else is */ 418 /* called. */ 419 /*......................................................................*/ 420 421 static void 422 datum_pts_init(void) 423 { 424 425 /* */ 426 /*...... open up the log file if we are debugging ......................*/ 427 /* */ 428 429 /* 430 ** Open up the log file if we are debugging. For now, send data out to the 431 ** screen (stdout). 432 */ 433 434 #ifdef DEBUG_DATUM_PTC 435 if (debug) 436 printf("Init Datum PTS\n"); 437 #endif 438 439 /* 440 ** Initialize the time request command string. This is the only message 441 ** that we ever have to send to the Datum PTS (although others are defined). 442 */ 443 444 memcpy(TIME_REQUEST, "//k/mn",6); 445 446 /* 447 ** Initialize the number of units to 0 and set the dynamic array of units to 448 ** NULL since there are no units defined yet. 449 */ 450 451 nunits = 0; 452 453 } 454 455 456 /*......................................................................*/ 457 /* datum_pts_buginfo - not used */ 458 /*......................................................................*/ 459 460 static void 461 datum_pts_buginfo( 462 int unit, 463 register struct refclockbug *bug, 464 register struct peer *peer 465 ) 466 { 467 468 #ifdef DEBUG_DATUM_PTC 469 if (debug) 470 printf("Buginfo Datum PTS\n"); 471 #endif 472 473 } 474 475 476 /*......................................................................*/ 477 /* datum_pts_receive - receive the time buffer that was read in */ 478 /* by the ntpd io handling routines. When 7 bytes have been */ 479 /* received (it may take several tries before all 7 bytes are */ 480 /* received), then the time code must be unpacked and sent to */ 481 /* the ntpd clock_receive() routine which causes the systems */ 482 /* clock to be updated (several layers down). */ 483 /*......................................................................*/ 484 485 static void 486 datum_pts_receive( 487 struct recvbuf *rbufp 488 ) 489 { 490 int i; 491 l_fp tstmp; 492 struct peer *p; 493 struct datum_pts_unit *datum_pts; 494 char *dpt; 495 int dpend; 496 int tzoff; 497 int timerr; 498 double ftimerr, abserr; 499 #ifdef DEBUG_DATUM_PTC 500 double dispersion; 501 #endif 502 int goodtime; 503 /*double doffset;*/ 504 505 /* 506 ** Get the time code (maybe partial) message out of the rbufp buffer. 507 */ 508 509 p = rbufp->recv_peer; 510 datum_pts = p->procptr->unitptr; 511 dpt = (char *)&rbufp->recv_space; 512 dpend = rbufp->recv_length; 513 514 #ifdef DEBUG_DATUM_PTC 515 if (debug) 516 printf("Receive Datum PTS: %d bytes\n", dpend); 517 #endif 518 519 /* */ 520 /*...... save the ntp system time when the first byte is received ......*/ 521 /* */ 522 523 /* 524 ** Save the ntp system time when the first byte is received. Note that 525 ** because it may take several calls to this routine before all seven 526 ** bytes of our return message are finally received by the io handlers in 527 ** ntpd, we really do want to use the time tag when the first byte is 528 ** received to reduce the jitter. 529 */ 530 531 if (datum_pts->nbytes == 0) { 532 datum_pts->lastrec = rbufp->recv_time; 533 } 534 535 /* 536 ** Increment our count to the number of bytes received so far. Return if we 537 ** haven't gotten all seven bytes yet. 538 */ 539 540 for (i=0; i<dpend; i++) { 541 datum_pts->retbuf[datum_pts->nbytes+i] = dpt[i]; 542 } 543 544 datum_pts->nbytes += dpend; 545 546 if (datum_pts->nbytes != 7) { 547 return; 548 } 549 550 /* 551 ** Convert the seven bytes received in our time buffer to day, hour, minute, 552 ** second, and msecond values. The usec value is not used for anything 553 ** currently. It is just the fractional part of the time stored in units 554 ** of microseconds. 555 */ 556 557 datum_pts->day = 100*(datum_pts->retbuf[0] & 0x0f) + 558 10*((datum_pts->retbuf[1] & 0xf0)>>4) + 559 (datum_pts->retbuf[1] & 0x0f); 560 561 datum_pts->hour = 10*((datum_pts->retbuf[2] & 0x30)>>4) + 562 (datum_pts->retbuf[2] & 0x0f); 563 564 datum_pts->minute = 10*((datum_pts->retbuf[3] & 0x70)>>4) + 565 (datum_pts->retbuf[3] & 0x0f); 566 567 datum_pts->second = 10*((datum_pts->retbuf[4] & 0x70)>>4) + 568 (datum_pts->retbuf[4] & 0x0f); 569 570 datum_pts->msec = 100*((datum_pts->retbuf[5] & 0xf0) >> 4) + 571 10*(datum_pts->retbuf[5] & 0x0f) + 572 ((datum_pts->retbuf[6] & 0xf0)>>4); 573 574 datum_pts->usec = 1000*datum_pts->msec; 575 576 #ifdef DEBUG_DATUM_PTC 577 if (debug) 578 printf("day %d, hour %d, minute %d, second %d, msec %d\n", 579 datum_pts->day, 580 datum_pts->hour, 581 datum_pts->minute, 582 datum_pts->second, 583 datum_pts->msec); 584 #endif 585 586 /* 587 ** Get the GMT time zone offset. Note that GMT should be zero if the Datum 588 ** reference time is using GMT as its time base. Otherwise we have to 589 ** determine the offset if the Datum PTS is using time of day as its time 590 ** base. 591 */ 592 593 goodtime = 0; /* We are not sure about the time and offset yet */ 594 595 #ifdef GMT 596 597 /* 598 ** This is the case where the Datum PTS is using GMT so there is no time 599 ** zone offset. 600 */ 601 602 tzoff = 0; /* set time zone offset to 0 */ 603 604 #else 605 606 /* 607 ** This is the case where the Datum PTS is using regular time of day for its 608 ** time so we must compute the time zone offset. The way we do it is kind of 609 ** funny but it works. We loop through different time zones (0 to 24) and 610 ** pick the one that gives the smallest error (+- one half hour). The time 611 ** zone offset is stored in the datum_pts structure for future use. Normally, 612 ** the clocktime() routine is only called once (unless the time zone offset 613 ** changes due to daylight savings) since the goodtime flag is set when a 614 ** good time is found (with a good offset). Note that even if the Datum 615 ** PTS is using GMT, this mechanism will still work since it should come up 616 ** with a value for tzoff = 0 (assuming that your system clock is within 617 ** a half hour of the Datum time (even with time zone differences). 618 */ 619 620 for (tzoff=0; tzoff<24; tzoff++) { 621 if (clocktime( datum_pts->day, 622 datum_pts->hour, 623 datum_pts->minute, 624 datum_pts->second, 625 (tzoff + datum_pts->tzoff) % 24, 626 datum_pts->lastrec.l_ui, 627 &datum_pts->yearstart, 628 &datum_pts->lastref.l_ui) ) { 629 630 datum_pts->lastref.l_uf = 0; 631 error = datum_pts->lastref.l_ui - datum_pts->lastrec.l_ui; 632 633 #ifdef DEBUG_DATUM_PTC 634 printf("Time Zone (clocktime method) = %d, error = %d\n", tzoff, error); 635 #endif 636 637 if ((error < 1799) && (error > -1799)) { 638 tzoff = (tzoff + datum_pts->tzoff) % 24; 639 datum_pts->tzoff = tzoff; 640 goodtime = 1; 641 642 #ifdef DEBUG_DATUM_PTC 643 printf("Time Zone found (clocktime method) = %d\n",tzoff); 644 #endif 645 646 break; 647 } 648 649 } 650 } 651 652 #endif 653 654 /* 655 ** Make sure that we have a good time from the Datum PTS. Clocktime() also 656 ** sets yearstart and lastref.l_ui. We will have to set astref.l_uf (i.e., 657 ** the fraction of a second) stuff later. 658 */ 659 660 if (!goodtime) { 661 662 if (!clocktime( datum_pts->day, 663 datum_pts->hour, 664 datum_pts->minute, 665 datum_pts->second, 666 tzoff, 667 datum_pts->lastrec.l_ui, 668 &datum_pts->yearstart, 669 &datum_pts->lastref.l_ui) ) { 670 671 #ifdef DEBUG_DATUM_PTC 672 if (debug) 673 { 674 printf("Error: bad clocktime\n"); 675 printf("GMT %d, lastrec %d, yearstart %d, lastref %d\n", 676 tzoff, 677 datum_pts->lastrec.l_ui, 678 datum_pts->yearstart, 679 datum_pts->lastref.l_ui); 680 } 681 #endif 682 683 msyslog(LOG_ERR, "Datum_PTS: Bad clocktime"); 684 685 return; 686 687 }else{ 688 689 #ifdef DEBUG_DATUM_PTC 690 if (debug) 691 printf("Good clocktime\n"); 692 #endif 693 694 } 695 696 } 697 698 /* 699 ** We have datum_pts->lastref.l_ui set (which is the integer part of the 700 ** time. Now set the microseconds field. 701 */ 702 703 TVUTOTSF(datum_pts->usec, datum_pts->lastref.l_uf); 704 705 /* 706 ** Compute the time correction as the difference between the reference 707 ** time (i.e., the Datum time) minus the receive time (system time). 708 */ 709 710 tstmp = datum_pts->lastref; /* tstmp is the datum ntp time */ 711 L_SUB(&tstmp, &datum_pts->lastrec); /* tstmp is now the correction */ 712 datum_pts->coderecv++; /* increment a counter */ 713 714 #ifdef DEBUG_DATUM_PTC 715 dispersion = DATUM_DISPERSION; /* set the dispersion to 0 */ 716 ftimerr = dispersion; 717 ftimerr /= (1024.0 * 64.0); 718 if (debug) 719 printf("dispersion = %d, %f\n", dispersion, ftimerr); 720 #endif 721 722 /* 723 ** Pass the new time to ntpd through the refclock_receive function. Note 724 ** that we are not trying to make any corrections due to the time it takes 725 ** for the Datum PTS to send the message back. I am (erroneously) assuming 726 ** that the time for the Datum PTS to send the time back to us is negligable. 727 ** I suspect that this time delay may be as much as 15 ms or so (but probably 728 ** less). For our needs at JPL, this kind of error is ok so it is not 729 ** necessary to use fudge factors in the ntp.conf file. Maybe later we will. 730 */ 731 /*LFPTOD(&tstmp, doffset);*/ 732 datum_pts->lastref = datum_pts->lastrec; 733 refclock_receive(datum_pts->peer); 734 735 /* 736 ** Compute sigma squared (not used currently). Maybe later, this could be 737 ** used for the dispersion estimate. The problem is that ntpd does not link 738 ** in the math library so sqrt() is not available. Anyway, this is useful 739 ** for debugging. Maybe later I will just use absolute values for the time 740 ** error to come up with my dispersion estimate. Anyway, for now my dispersion 741 ** is set to 0. 742 */ 743 744 timerr = tstmp.l_ui<<20; 745 timerr |= (tstmp.l_uf>>12) & 0x000fffff; 746 ftimerr = timerr; 747 ftimerr /= 1024*1024; 748 abserr = ftimerr; 749 if (ftimerr < 0.0) abserr = -ftimerr; 750 751 if (datum_pts->sigma2 == 0.0) { 752 if (abserr < DATUM_MAX_ERROR) { 753 datum_pts->sigma2 = abserr*abserr; 754 }else{ 755 datum_pts->sigma2 = DATUM_MAX_ERROR2; 756 } 757 }else{ 758 if (abserr < DATUM_MAX_ERROR) { 759 datum_pts->sigma2 = 0.95*datum_pts->sigma2 + 0.05*abserr*abserr; 760 }else{ 761 datum_pts->sigma2 = 0.95*datum_pts->sigma2 + 0.05*DATUM_MAX_ERROR2; 762 } 763 } 764 765 #ifdef DEBUG_DATUM_PTC 766 if (debug) 767 printf("Time error = %f seconds\n", ftimerr); 768 #endif 769 770 #if defined(DEBUG_DATUM_PTC) || defined(LOG_TIME_ERRORS) 771 if (debug) 772 printf("PTS: day %d, hour %d, minute %d, second %d, msec %d, Time Error %f\n", 773 datum_pts->day, 774 datum_pts->hour, 775 datum_pts->minute, 776 datum_pts->second, 777 datum_pts->msec, 778 ftimerr); 779 #endif 780 781 } 782 #else 783 NONEMPTY_TRANSLATION_UNIT 784 #endif /* REFCLOCK */ 785