Annotation of embedaddon/ntp/ntpd/refclock_datum.c, revision 1.1.1.1
1.1 misho 1: /*
2: ** refclock_datum - clock driver for the Datum Programmable Time Server
3: **
4: ** Important note: This driver assumes that you have termios. If you have
5: ** a system that does not have termios, you will have to modify this driver.
6: **
7: ** Sorry, I have only tested this driver on SUN and HP platforms.
8: */
9:
10: #ifdef HAVE_CONFIG_H
11: # include <config.h>
12: #endif
13:
14: #if defined(REFCLOCK) && defined(CLOCK_DATUM)
15:
16: /*
17: ** Include Files
18: */
19:
20: #include "ntpd.h"
21: #include "ntp_io.h"
22: #include "ntp_refclock.h"
23: #include "ntp_unixtime.h"
24: #include "ntp_stdlib.h"
25:
26: #include <stdio.h>
27: #include <ctype.h>
28:
29: #if defined(HAVE_BSD_TTYS)
30: #include <sgtty.h>
31: #endif /* HAVE_BSD_TTYS */
32:
33: #if defined(HAVE_SYSV_TTYS)
34: #include <termio.h>
35: #endif /* HAVE_SYSV_TTYS */
36:
37: #if defined(HAVE_TERMIOS)
38: #include <termios.h>
39: #endif
40: #if defined(STREAM)
41: #include <stropts.h>
42: #if defined(WWVBCLK)
43: #include <sys/clkdefs.h>
44: #endif /* WWVBCLK */
45: #endif /* STREAM */
46:
47: #include "ntp_stdlib.h"
48:
49: /*
50: ** This driver supports the Datum Programmable Time System (PTS) clock.
51: ** The clock works in very straight forward manner. When it receives a
52: ** time code request (e.g., the ascii string "//k/mn"), it responds with
53: ** a seven byte BCD time code. This clock only responds with a
54: ** time code after it first receives the "//k/mn" message. It does not
55: ** periodically send time codes back at some rate once it is started.
56: ** the returned time code can be broken down into the following fields.
57: **
58: ** _______________________________
59: ** Bit Index | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
60: ** ===============================
61: ** byte 0: | - - - - | H D |
62: ** ===============================
63: ** byte 1: | T D | U D |
64: ** ===============================
65: ** byte 2: | - - | T H | U H |
66: ** ===============================
67: ** byte 3: | - | T M | U M |
68: ** ===============================
69: ** byte 4: | - | T S | U S |
70: ** ===============================
71: ** byte 5: | t S | h S |
72: ** ===============================
73: ** byte 6: | m S | - - - - |
74: ** ===============================
75: **
76: ** In the table above:
77: **
78: ** "-" means don't care
79: ** "H D", "T D", and "U D" means Hundreds, Tens, and Units of Days
80: ** "T H", and "UH" means Tens and Units of Hours
81: ** "T M", and "U M" means Tens and Units of Minutes
82: ** "T S", and "U S" means Tens and Units of Seconds
83: ** "t S", "h S", and "m S" means tenths, hundredths, and thousandths
84: ** of seconds
85: **
86: ** The Datum PTS communicates throught the RS232 port on your machine.
87: ** Right now, it assumes that you have termios. This driver has been tested
88: ** on SUN and HP workstations. The Datum PTS supports various IRIG and
89: ** NASA input codes. This driver assumes that the name of the device is
90: ** /dev/datum. You will need to make a soft link to your RS232 device or
91: ** create a new driver to use this refclock.
92: */
93:
94: /*
95: ** Datum PTS defines
96: */
97:
98: /*
99: ** Note that if GMT is defined, then the Datum PTS must use Greenwich
100: ** time. Otherwise, this driver allows the Datum PTS to use the current
101: ** wall clock for its time. It determines the time zone offset by minimizing
102: ** the error after trying several time zone offsets. If the Datum PTS
103: ** time is Greenwich time and GMT is not defined, everything should still
104: ** work since the time zone will be found to be 0. What this really means
105: ** is that your system time (at least to start with) must be within the
106: ** correct time by less than +- 30 minutes. The default is for GMT to not
107: ** defined. If you really want to force GMT without the funny +- 30 minute
108: ** stuff then you must define (uncomment) GMT below.
109: */
110:
111: /*
112: #define GMT
113: #define DEBUG_DATUM_PTC
114: #define LOG_TIME_ERRORS
115: */
116:
117:
118: #define PRECISION (-10) /* precision assumed 1/1024 ms */
119: #define REFID "DATM" /* reference id */
120: #define DATUM_DISPERSION 0 /* fixed dispersion = 0 ms */
121: #define DATUM_MAX_ERROR 0.100 /* limits on sigma squared */
122: #define DATUM_DEV "/dev/datum" /* device name */
123:
124: #define DATUM_MAX_ERROR2 (DATUM_MAX_ERROR*DATUM_MAX_ERROR)
125:
126: /*
127: ** The Datum PTS structure
128: */
129:
130: /*
131: ** I don't use a fixed array of MAXUNITS like everyone else just because
132: ** I don't like to program that way. Sorry if this bothers anyone. I assume
133: ** that you can use any id for your unit and I will search for it in a
134: ** dynamic array of units until I find it. I was worried that users might
135: ** enter a bad id in their configuration file (larger than MAXUNITS) and
136: ** besides, it is just cleaner not to have to assume that you have a fixed
137: ** number of anything in a program.
138: */
139:
140: struct datum_pts_unit {
141: struct peer *peer; /* peer used by ntp */
142: struct refclockio io; /* io structure used by ntp */
143: int PTS_fd; /* file descriptor for PTS */
144: u_int unit; /* id for unit */
145: u_long timestarted; /* time started */
146: l_fp lastrec; /* time tag for the receive time (system) */
147: l_fp lastref; /* reference time (Datum time) */
148: u_long yearstart; /* the year that this clock started */
149: int coderecv; /* number of time codes received */
150: int day; /* day */
151: int hour; /* hour */
152: int minute; /* minutes */
153: int second; /* seconds */
154: int msec; /* miliseconds */
155: int usec; /* miliseconds */
156: u_char leap; /* funny leap character code */
157: char retbuf[8]; /* returned time from the datum pts */
158: char nbytes; /* number of bytes received from datum pts */
159: double sigma2; /* average squared error (roughly) */
160: int tzoff; /* time zone offest from GMT */
161: };
162:
163: /*
164: ** PTS static constant variables for internal use
165: */
166:
167: static char TIME_REQUEST[6]; /* request message sent to datum for time */
168: static int nunits; /* number of active units */
169: static struct datum_pts_unit
170: **datum_pts_unit; /* dynamic array of datum PTS structures */
171:
172: /*
173: ** Callback function prototypes that ntpd needs to know about.
174: */
175:
176: static int datum_pts_start (int, struct peer *);
177: static void datum_pts_shutdown (int, struct peer *);
178: static void datum_pts_poll (int, struct peer *);
179: static void datum_pts_control (int, struct refclockstat *,
180: struct refclockstat *, struct peer *);
181: static void datum_pts_init (void);
182: static void datum_pts_buginfo (int, struct refclockbug *, struct peer *);
183:
184: /*
185: ** This is the call back function structure that ntpd actually uses for
186: ** this refclock.
187: */
188:
189: struct refclock refclock_datum = {
190: datum_pts_start, /* start up a new Datum refclock */
191: datum_pts_shutdown, /* shutdown a Datum refclock */
192: datum_pts_poll, /* sends out the time request */
193: datum_pts_control, /* not used */
194: datum_pts_init, /* initialization (called first) */
195: datum_pts_buginfo, /* not used */
196: NOFLAGS /* we are not setting any special flags */
197: };
198:
199: /*
200: ** The datum_pts_receive callback function is handled differently from the
201: ** rest. It is passed to the ntpd io data structure. Basically, every
202: ** 64 seconds, the datum_pts_poll() routine is called. It sends out the time
203: ** request message to the Datum Programmable Time System. Then, ntpd
204: ** waits on a select() call to receive data back. The datum_pts_receive()
205: ** function is called as data comes back. We expect a seven byte time
206: ** code to be returned but the datum_pts_receive() function may only get
207: ** a few bytes passed to it at a time. In other words, this routine may
208: ** get called by the io stuff in ntpd a few times before we get all seven
209: ** bytes. Once the last byte is received, we process it and then pass the
210: ** new time measurement to ntpd for updating the system time. For now,
211: ** there is no 3 state filtering done on the time measurements. The
212: ** jitter may be a little high but at least for its current use, it is not
213: ** a problem. We have tried to keep things as simple as possible. This
214: ** clock should not jitter more than 1 or 2 mseconds at the most once
215: ** things settle down. It is important to get the right drift calibrated
216: ** in the ntpd.drift file as well as getting the right tick set up right
217: ** using tickadj for SUNs. Tickadj is not used for the HP but you need to
218: ** remember to bring up the adjtime daemon because HP does not support
219: ** the adjtime() call.
220: */
221:
222: static void datum_pts_receive (struct recvbuf *);
223:
224: /*......................................................................*/
225: /* datum_pts_start - start up the datum PTS. This means open the */
226: /* RS232 device and set up the data structure for my unit. */
227: /*......................................................................*/
228:
229: static int
230: datum_pts_start(
231: int unit,
232: struct peer *peer
233: )
234: {
235: struct datum_pts_unit **temp_datum_pts_unit;
236: struct datum_pts_unit *datum_pts;
237: int fd;
238: #ifdef HAVE_TERMIOS
239: struct termios arg;
240: #endif
241:
242: #ifdef DEBUG_DATUM_PTC
243: if (debug)
244: printf("Starting Datum PTS unit %d\n", unit);
245: #endif
246:
247: /*
248: ** Open the Datum PTS device
249: */
250: fd = open(DATUM_DEV, O_RDWR);
251:
252: if (fd < 0) {
253: msyslog(LOG_ERR, "Datum_PTS: open(\"%s\", O_RDWR) failed: %m", DATUM_DEV);
254: return 0;
255: }
256:
257: /*
258: ** Create the memory for the new unit
259: */
260:
261: temp_datum_pts_unit = (struct datum_pts_unit **)
262: emalloc((nunits+1)*sizeof(struct datum_pts_unit *));
263: if (nunits > 0) memcpy(temp_datum_pts_unit, datum_pts_unit,
264: nunits*sizeof(struct datum_pts_unit *));
265: free(datum_pts_unit);
266: datum_pts_unit = temp_datum_pts_unit;
267: datum_pts_unit[nunits] = (struct datum_pts_unit *)
268: emalloc(sizeof(struct datum_pts_unit));
269: datum_pts = datum_pts_unit[nunits];
270:
271: datum_pts->unit = unit; /* set my unit id */
272: datum_pts->yearstart = 0; /* initialize the yearstart to 0 */
273: datum_pts->sigma2 = 0.0; /* initialize the sigma2 to 0 */
274:
275: datum_pts->PTS_fd = fd;
276:
277: fcntl(datum_pts->PTS_fd, F_SETFL, 0); /* clear the descriptor flags */
278:
279: #ifdef DEBUG_DATUM_PTC
280: if (debug)
281: printf("Opening RS232 port with file descriptor %d\n",
282: datum_pts->PTS_fd);
283: #endif
284:
285: /*
286: ** Set up the RS232 terminal device information. Note that we assume that
287: ** we have termios. This code has only been tested on SUNs and HPs. If your
288: ** machine does not have termios this driver cannot be initialized. You can change this
289: ** if you want by editing this source. Please give the changes back to the
290: ** ntp folks so that it can become part of their regular distribution.
291: */
292:
293: #ifdef HAVE_TERMIOS
294:
295: memset(&arg, 0, sizeof(arg));
296:
297: arg.c_iflag = IGNBRK;
298: arg.c_oflag = 0;
299: arg.c_cflag = B9600 | CS8 | CREAD | PARENB | CLOCAL;
300: arg.c_lflag = 0;
301: arg.c_cc[VMIN] = 0; /* start timeout timer right away (not used) */
302: arg.c_cc[VTIME] = 30; /* 3 second timout on reads (not used) */
303:
304: tcsetattr(datum_pts->PTS_fd, TCSANOW, &arg);
305:
306: #else
307:
308: msyslog(LOG_ERR, "Datum_PTS: Termios not supported in this driver");
309: (void)close(datum_pts->PTS_fd);
310:
311: peer->precision = PRECISION;
312: pp->clockdesc = DESCRIPTION;
313: memcpy((char *)&pp->refid, REFID, 4);
314:
315: return 0;
316:
317: #endif
318:
319: /*
320: ** Initialize the ntpd IO structure
321: */
322:
323: datum_pts->peer = peer;
324: datum_pts->io.clock_recv = datum_pts_receive;
325: datum_pts->io.srcclock = (caddr_t)datum_pts;
326: datum_pts->io.datalen = 0;
327: datum_pts->io.fd = datum_pts->PTS_fd;
328:
329: if (!io_addclock(&(datum_pts->io))) {
330:
331: #ifdef DEBUG_DATUM_PTC
332: if (debug)
333: printf("Problem adding clock\n");
334: #endif
335:
336: msyslog(LOG_ERR, "Datum_PTS: Problem adding clock");
337: (void)close(datum_pts->PTS_fd);
338:
339: return 0;
340: }
341:
342: /*
343: ** Now add one to the number of units and return a successful code
344: */
345:
346: nunits++;
347: return 1;
348:
349: }
350:
351:
352: /*......................................................................*/
353: /* datum_pts_shutdown - this routine shuts doen the device and */
354: /* removes the memory for the unit. */
355: /*......................................................................*/
356:
357: static void
358: datum_pts_shutdown(
359: int unit,
360: struct peer *peer
361: )
362: {
363: int i,j;
364: struct datum_pts_unit **temp_datum_pts_unit;
365:
366: #ifdef DEBUG_DATUM_PTC
367: if (debug)
368: printf("Shutdown Datum PTS\n");
369: #endif
370:
371: msyslog(LOG_ERR, "Datum_PTS: Shutdown Datum PTS");
372:
373: /*
374: ** First we have to find the right unit (i.e., the one with the same id).
375: ** We do this by looping through the dynamic array of units intil we find
376: ** it. Note, that I don't simply use an array with a maximimum number of
377: ** Datum PTS units. Everything is completely dynamic.
378: */
379:
380: for (i=0; i<nunits; i++) {
381: if (datum_pts_unit[i]->unit == unit) {
382:
383: /*
384: ** We found the unit so close the file descriptor and free up the memory used
385: ** by the structure.
386: */
387:
388: io_closeclock(&datum_pts_unit[i]->io);
389: close(datum_pts_unit[i]->PTS_fd);
390: free(datum_pts_unit[i]);
391:
392: /*
393: ** Now clean up the datum_pts_unit dynamic array so that there are no holes.
394: ** This may mean moving pointers around, etc., to keep things compact.
395: */
396:
397: if (nunits > 1) {
398:
399: temp_datum_pts_unit = (struct datum_pts_unit **)
400: emalloc((nunits-1)*sizeof(struct datum_pts_unit *));
401: if (i!= 0) memcpy(temp_datum_pts_unit, datum_pts_unit,
402: i*sizeof(struct datum_pts_unit *));
403:
404: for (j=i+1; j<nunits; j++) {
405: temp_datum_pts_unit[j-1] = datum_pts_unit[j];
406: }
407:
408: free(datum_pts_unit);
409: datum_pts_unit = temp_datum_pts_unit;
410:
411: }else{
412:
413: free(datum_pts_unit);
414: datum_pts_unit = NULL;
415:
416: }
417:
418: return;
419:
420: }
421: }
422:
423: #ifdef DEBUG_DATUM_PTC
424: if (debug)
425: printf("Error, could not shut down unit %d\n",unit);
426: #endif
427:
428: msyslog(LOG_ERR, "Datum_PTS: Could not shut down Datum PTS unit %d",unit);
429:
430: }
431:
432: /*......................................................................*/
433: /* datum_pts_poll - this routine sends out the time request to the */
434: /* Datum PTS device. The time will be passed back in the */
435: /* datum_pts_receive() routine. */
436: /*......................................................................*/
437:
438: static void
439: datum_pts_poll(
440: int unit,
441: struct peer *peer
442: )
443: {
444: int i;
445: int unit_index;
446: int error_code;
447: struct datum_pts_unit *datum_pts;
448:
449: #ifdef DEBUG_DATUM_PTC
450: if (debug)
451: printf("Poll Datum PTS\n");
452: #endif
453:
454: /*
455: ** Find the right unit and send out a time request once it is found.
456: */
457:
458: unit_index = -1;
459: for (i=0; i<nunits; i++) {
460: if (datum_pts_unit[i]->unit == unit) {
461: unit_index = i;
462: datum_pts = datum_pts_unit[i];
463: error_code = write(datum_pts->PTS_fd, TIME_REQUEST, 6);
464: if (error_code != 6) perror("TIME_REQUEST");
465: datum_pts->nbytes = 0;
466: break;
467: }
468: }
469:
470: /*
471: ** Print out an error message if we could not find the right unit.
472: */
473:
474: if (unit_index == -1) {
475:
476: #ifdef DEBUG_DATUM_PTC
477: if (debug)
478: printf("Error, could not poll unit %d\n",unit);
479: #endif
480:
481: msyslog(LOG_ERR, "Datum_PTS: Could not poll unit %d",unit);
482: return;
483:
484: }
485:
486: }
487:
488:
489: /*......................................................................*/
490: /* datum_pts_control - not used */
491: /*......................................................................*/
492:
493: static void
494: datum_pts_control(
495: int unit,
496: struct refclockstat *in,
497: struct refclockstat *out,
498: struct peer *peer
499: )
500: {
501:
502: #ifdef DEBUG_DATUM_PTC
503: if (debug)
504: printf("Control Datum PTS\n");
505: #endif
506:
507: }
508:
509:
510: /*......................................................................*/
511: /* datum_pts_init - initializes things for all possible Datum */
512: /* time code generators that might be used. In practice, this is */
513: /* only called once at the beginning before anything else is */
514: /* called. */
515: /*......................................................................*/
516:
517: static void
518: datum_pts_init(void)
519: {
520:
521: /* */
522: /*...... open up the log file if we are debugging ......................*/
523: /* */
524:
525: /*
526: ** Open up the log file if we are debugging. For now, send data out to the
527: ** screen (stdout).
528: */
529:
530: #ifdef DEBUG_DATUM_PTC
531: if (debug)
532: printf("Init Datum PTS\n");
533: #endif
534:
535: /*
536: ** Initialize the time request command string. This is the only message
537: ** that we ever have to send to the Datum PTS (although others are defined).
538: */
539:
540: memcpy(TIME_REQUEST, "//k/mn",6);
541:
542: /*
543: ** Initialize the number of units to 0 and set the dynamic array of units to
544: ** NULL since there are no units defined yet.
545: */
546:
547: datum_pts_unit = NULL;
548: nunits = 0;
549:
550: }
551:
552:
553: /*......................................................................*/
554: /* datum_pts_buginfo - not used */
555: /*......................................................................*/
556:
557: static void
558: datum_pts_buginfo(
559: int unit,
560: register struct refclockbug *bug,
561: register struct peer *peer
562: )
563: {
564:
565: #ifdef DEBUG_DATUM_PTC
566: if (debug)
567: printf("Buginfo Datum PTS\n");
568: #endif
569:
570: }
571:
572:
573: /*......................................................................*/
574: /* datum_pts_receive - receive the time buffer that was read in */
575: /* by the ntpd io handling routines. When 7 bytes have been */
576: /* received (it may take several tries before all 7 bytes are */
577: /* received), then the time code must be unpacked and sent to */
578: /* the ntpd clock_receive() routine which causes the systems */
579: /* clock to be updated (several layers down). */
580: /*......................................................................*/
581:
582: static void
583: datum_pts_receive(
584: struct recvbuf *rbufp
585: )
586: {
587: int i;
588: l_fp tstmp;
589: struct datum_pts_unit *datum_pts;
590: char *dpt;
591: int dpend;
592: int tzoff;
593: int timerr;
594: double ftimerr, abserr;
595: #ifdef DEBUG_DATUM_PTC
596: double dispersion;
597: #endif
598: int goodtime;
599: /*double doffset;*/
600:
601: /*
602: ** Get the time code (maybe partial) message out of the rbufp buffer.
603: */
604:
605: datum_pts = (struct datum_pts_unit *)rbufp->recv_srcclock;
606: dpt = (char *)&rbufp->recv_space;
607: dpend = rbufp->recv_length;
608:
609: #ifdef DEBUG_DATUM_PTC
610: if (debug)
611: printf("Receive Datum PTS: %d bytes\n", dpend);
612: #endif
613:
614: /* */
615: /*...... save the ntp system time when the first byte is received ......*/
616: /* */
617:
618: /*
619: ** Save the ntp system time when the first byte is received. Note that
620: ** because it may take several calls to this routine before all seven
621: ** bytes of our return message are finally received by the io handlers in
622: ** ntpd, we really do want to use the time tag when the first byte is
623: ** received to reduce the jitter.
624: */
625:
626: if (datum_pts->nbytes == 0) {
627: datum_pts->lastrec = rbufp->recv_time;
628: }
629:
630: /*
631: ** Increment our count to the number of bytes received so far. Return if we
632: ** haven't gotten all seven bytes yet.
633: */
634:
635: for (i=0; i<dpend; i++) {
636: datum_pts->retbuf[datum_pts->nbytes+i] = dpt[i];
637: }
638:
639: datum_pts->nbytes += dpend;
640:
641: if (datum_pts->nbytes != 7) {
642: return;
643: }
644:
645: /*
646: ** Convert the seven bytes received in our time buffer to day, hour, minute,
647: ** second, and msecond values. The usec value is not used for anything
648: ** currently. It is just the fractional part of the time stored in units
649: ** of microseconds.
650: */
651:
652: datum_pts->day = 100*(datum_pts->retbuf[0] & 0x0f) +
653: 10*((datum_pts->retbuf[1] & 0xf0)>>4) +
654: (datum_pts->retbuf[1] & 0x0f);
655:
656: datum_pts->hour = 10*((datum_pts->retbuf[2] & 0x30)>>4) +
657: (datum_pts->retbuf[2] & 0x0f);
658:
659: datum_pts->minute = 10*((datum_pts->retbuf[3] & 0x70)>>4) +
660: (datum_pts->retbuf[3] & 0x0f);
661:
662: datum_pts->second = 10*((datum_pts->retbuf[4] & 0x70)>>4) +
663: (datum_pts->retbuf[4] & 0x0f);
664:
665: datum_pts->msec = 100*((datum_pts->retbuf[5] & 0xf0) >> 4) +
666: 10*(datum_pts->retbuf[5] & 0x0f) +
667: ((datum_pts->retbuf[6] & 0xf0)>>4);
668:
669: datum_pts->usec = 1000*datum_pts->msec;
670:
671: #ifdef DEBUG_DATUM_PTC
672: if (debug)
673: printf("day %d, hour %d, minute %d, second %d, msec %d\n",
674: datum_pts->day,
675: datum_pts->hour,
676: datum_pts->minute,
677: datum_pts->second,
678: datum_pts->msec);
679: #endif
680:
681: /*
682: ** Get the GMT time zone offset. Note that GMT should be zero if the Datum
683: ** reference time is using GMT as its time base. Otherwise we have to
684: ** determine the offset if the Datum PTS is using time of day as its time
685: ** base.
686: */
687:
688: goodtime = 0; /* We are not sure about the time and offset yet */
689:
690: #ifdef GMT
691:
692: /*
693: ** This is the case where the Datum PTS is using GMT so there is no time
694: ** zone offset.
695: */
696:
697: tzoff = 0; /* set time zone offset to 0 */
698:
699: #else
700:
701: /*
702: ** This is the case where the Datum PTS is using regular time of day for its
703: ** time so we must compute the time zone offset. The way we do it is kind of
704: ** funny but it works. We loop through different time zones (0 to 24) and
705: ** pick the one that gives the smallest error (+- one half hour). The time
706: ** zone offset is stored in the datum_pts structure for future use. Normally,
707: ** the clocktime() routine is only called once (unless the time zone offset
708: ** changes due to daylight savings) since the goodtime flag is set when a
709: ** good time is found (with a good offset). Note that even if the Datum
710: ** PTS is using GMT, this mechanism will still work since it should come up
711: ** with a value for tzoff = 0 (assuming that your system clock is within
712: ** a half hour of the Datum time (even with time zone differences).
713: */
714:
715: for (tzoff=0; tzoff<24; tzoff++) {
716: if (clocktime( datum_pts->day,
717: datum_pts->hour,
718: datum_pts->minute,
719: datum_pts->second,
720: (tzoff + datum_pts->tzoff) % 24,
721: datum_pts->lastrec.l_ui,
722: &datum_pts->yearstart,
723: &datum_pts->lastref.l_ui) ) {
724:
725: datum_pts->lastref.l_uf = 0;
726: error = datum_pts->lastref.l_ui - datum_pts->lastrec.l_ui;
727:
728: #ifdef DEBUG_DATUM_PTC
729: printf("Time Zone (clocktime method) = %d, error = %d\n", tzoff, error);
730: #endif
731:
732: if ((error < 1799) && (error > -1799)) {
733: tzoff = (tzoff + datum_pts->tzoff) % 24;
734: datum_pts->tzoff = tzoff;
735: goodtime = 1;
736:
737: #ifdef DEBUG_DATUM_PTC
738: printf("Time Zone found (clocktime method) = %d\n",tzoff);
739: #endif
740:
741: break;
742: }
743:
744: }
745: }
746:
747: #endif
748:
749: /*
750: ** Make sure that we have a good time from the Datum PTS. Clocktime() also
751: ** sets yearstart and lastref.l_ui. We will have to set astref.l_uf (i.e.,
752: ** the fraction of a second) stuff later.
753: */
754:
755: if (!goodtime) {
756:
757: if (!clocktime( datum_pts->day,
758: datum_pts->hour,
759: datum_pts->minute,
760: datum_pts->second,
761: tzoff,
762: datum_pts->lastrec.l_ui,
763: &datum_pts->yearstart,
764: &datum_pts->lastref.l_ui) ) {
765:
766: #ifdef DEBUG_DATUM_PTC
767: if (debug)
768: {
769: printf("Error: bad clocktime\n");
770: printf("GMT %d, lastrec %d, yearstart %d, lastref %d\n",
771: tzoff,
772: datum_pts->lastrec.l_ui,
773: datum_pts->yearstart,
774: datum_pts->lastref.l_ui);
775: }
776: #endif
777:
778: msyslog(LOG_ERR, "Datum_PTS: Bad clocktime");
779:
780: return;
781:
782: }else{
783:
784: #ifdef DEBUG_DATUM_PTC
785: if (debug)
786: printf("Good clocktime\n");
787: #endif
788:
789: }
790:
791: }
792:
793: /*
794: ** We have datum_pts->lastref.l_ui set (which is the integer part of the
795: ** time. Now set the microseconds field.
796: */
797:
798: TVUTOTSF(datum_pts->usec, datum_pts->lastref.l_uf);
799:
800: /*
801: ** Compute the time correction as the difference between the reference
802: ** time (i.e., the Datum time) minus the receive time (system time).
803: */
804:
805: tstmp = datum_pts->lastref; /* tstmp is the datum ntp time */
806: L_SUB(&tstmp, &datum_pts->lastrec); /* tstmp is now the correction */
807: datum_pts->coderecv++; /* increment a counter */
808:
809: #ifdef DEBUG_DATUM_PTC
810: dispersion = DATUM_DISPERSION; /* set the dispersion to 0 */
811: ftimerr = dispersion;
812: ftimerr /= (1024.0 * 64.0);
813: if (debug)
814: printf("dispersion = %d, %f\n", dispersion, ftimerr);
815: #endif
816:
817: /*
818: ** Pass the new time to ntpd through the refclock_receive function. Note
819: ** that we are not trying to make any corrections due to the time it takes
820: ** for the Datum PTS to send the message back. I am (erroneously) assuming
821: ** that the time for the Datum PTS to send the time back to us is negligable.
822: ** I suspect that this time delay may be as much as 15 ms or so (but probably
823: ** less). For our needs at JPL, this kind of error is ok so it is not
824: ** necessary to use fudge factors in the ntp.conf file. Maybe later we will.
825: */
826: /*LFPTOD(&tstmp, doffset);*/
827: datum_pts->lastref = datum_pts->lastrec;
828: refclock_receive(datum_pts->peer);
829:
830: /*
831: ** Compute sigma squared (not used currently). Maybe later, this could be
832: ** used for the dispersion estimate. The problem is that ntpd does not link
833: ** in the math library so sqrt() is not available. Anyway, this is useful
834: ** for debugging. Maybe later I will just use absolute values for the time
835: ** error to come up with my dispersion estimate. Anyway, for now my dispersion
836: ** is set to 0.
837: */
838:
839: timerr = tstmp.l_ui<<20;
840: timerr |= (tstmp.l_uf>>12) & 0x000fffff;
841: ftimerr = timerr;
842: ftimerr /= 1024*1024;
843: abserr = ftimerr;
844: if (ftimerr < 0.0) abserr = -ftimerr;
845:
846: if (datum_pts->sigma2 == 0.0) {
847: if (abserr < DATUM_MAX_ERROR) {
848: datum_pts->sigma2 = abserr*abserr;
849: }else{
850: datum_pts->sigma2 = DATUM_MAX_ERROR2;
851: }
852: }else{
853: if (abserr < DATUM_MAX_ERROR) {
854: datum_pts->sigma2 = 0.95*datum_pts->sigma2 + 0.05*abserr*abserr;
855: }else{
856: datum_pts->sigma2 = 0.95*datum_pts->sigma2 + 0.05*DATUM_MAX_ERROR2;
857: }
858: }
859:
860: #ifdef DEBUG_DATUM_PTC
861: if (debug)
862: printf("Time error = %f seconds\n", ftimerr);
863: #endif
864:
865: #if defined(DEBUG_DATUM_PTC) || defined(LOG_TIME_ERRORS)
866: if (debug)
867: printf("PTS: day %d, hour %d, minute %d, second %d, msec %d, Time Error %f\n",
868: datum_pts->day,
869: datum_pts->hour,
870: datum_pts->minute,
871: datum_pts->second,
872: datum_pts->msec,
873: ftimerr);
874: #endif
875:
876: }
877: #else
878: int refclock_datum_bs;
879: #endif /* REFCLOCK */
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