xref: /netbsd-src/external/bsd/ntp/dist/ntpd/refclock_arc.c (revision 7788a0781fe6ff2cce37368b4578a7ade0850cb1)
1 /*	$NetBSD: refclock_arc.c,v 1.3 2012/02/01 07:46:22 kardel Exp $	*/
2 
3 /*
4  * refclock_arc - clock driver for ARCRON MSF/DCF/WWVB receivers
5  */
6 
7 #ifdef HAVE_CONFIG_H
8 #include <config.h>
9 #endif
10 
11 #if defined(REFCLOCK) && defined(CLOCK_ARCRON_MSF)
12 
13 static const char arc_version[] = { "V1.3 2003/02/21" };
14 
15 /* define PRE_NTP420 for compatibility to previous versions of NTP (at least
16    to 4.1.0 */
17 #undef PRE_NTP420
18 
19 #ifndef ARCRON_NOT_KEEN
20 #define ARCRON_KEEN 1 /* Be keen, and trusting of the clock, if defined. */
21 #endif
22 
23 #ifndef ARCRON_NOT_MULTIPLE_SAMPLES
24 #define ARCRON_MULTIPLE_SAMPLES 1 /* Use all timestamp bytes as samples. */
25 #endif
26 
27 #ifndef ARCRON_NOT_LEAPSECOND_KEEN
28 #ifndef ARCRON_LEAPSECOND_KEEN
29 #undef ARCRON_LEAPSECOND_KEEN /* Respond quickly to leap seconds: doesn't work yet. */
30 #endif
31 #endif
32 
33 /*
34 Code by Derek Mulcahy, <derek@toybox.demon.co.uk>, 1997.
35 Modifications by Damon Hart-Davis, <d@hd.org>, 1997.
36 Modifications by Paul Alfille, <palfille@partners.org>, 2003.
37 Modifications by Christopher Price, <cprice@cs-home.com>, 2003.
38 Modifications by Nigel Roles <nigel@9fs.org>, 2003.
39 
40 
41 THIS CODE IS SUPPLIED AS IS, WITH NO WARRANTY OF ANY KIND.  USE AT
42 YOUR OWN RISK.
43 
44 Orginally developed and used with ntp3-5.85 by Derek Mulcahy.
45 
46 Built against ntp3-5.90 on Solaris 2.5 using gcc 2.7.2.
47 
48 This code may be freely copied and used and incorporated in other
49 systems providing the disclaimer and notice of authorship are
50 reproduced.
51 
52 -------------------------------------------------------------------------------
53 
54 Nigel's notes:
55 
56 1) Called tcgetattr() before modifying, so that fields correctly initialised
57    for all operating systems
58 
59 2) Altered parsing of timestamp line so that it copes with fields which are
60    not always ASCII digits (e.g. status field when battery low)
61 
62 -------------------------------------------------------------------------------
63 
64 Christopher's notes:
65 
66 MAJOR CHANGES SINCE V1.2
67 ========================
68  1) Applied patch by Andrey Bray <abuse@madhouse.demon.co.uk>
69     2001-02-17 comp.protocols.time.ntp
70 
71  2) Added WWVB support via clock mode command, localtime/UTC time configured
72     via flag1=(0=UTC, 1=localtime)
73 
74  3) Added ignore resync request via flag2=(0=resync, 1=ignore resync)
75 
76  4) Added simplified conversion from localtime to UTC with dst/bst translation
77 
78  5) Added average signal quality poll
79 
80  6) Fixed a badformat error when no code is available due to stripping
81     \n & \r's
82 
83  7) Fixed a badformat error when clearing lencode & memset a_lastcode in poll
84     routine
85 
86  8) Lots of code cleanup, including standardized DEBUG macros and removal
87     of unused code
88 
89 -------------------------------------------------------------------------------
90 
91 Author's original note:
92 
93 I enclose my ntp driver for the Galleon Systems Arc MSF receiver.
94 
95 It works (after a fashion) on both Solaris-1 and Solaris-2.
96 
97 I am currently using ntp3-5.85.  I have been running the code for
98 about 7 months without any problems.  Even coped with the change to BST!
99 
100 I had to do some funky things to read from the clock because it uses the
101 power from the receive lines to drive the transmit lines.  This makes the
102 code look a bit stupid but it works.  I also had to put in some delays to
103 allow for the turnaround time from receive to transmit.  These delays
104 are between characters when requesting a time stamp so that shouldn't affect
105 the results too drastically.
106 
107 ...
108 
109 The bottom line is that it works but could easily be improved.  You are
110 free to do what you will with the code.  I haven't been able to determine
111 how good the clock is.  I think that this requires a known good clock
112 to compare it against.
113 
114 -------------------------------------------------------------------------------
115 
116 Damon's notes for adjustments:
117 
118 MAJOR CHANGES SINCE V1.0
119 ========================
120  1) Removal of pollcnt variable that made the clock go permanently
121     off-line once two time polls failed to gain responses.
122 
123  2) Avoiding (at least on Solaris-2) terminal becoming the controlling
124     terminal of the process when we do a low-level open().
125 
126  3) Additional logic (conditional on ARCRON_LEAPSECOND_KEEN being
127     defined) to try to resync quickly after a potential leap-second
128     insertion or deletion.
129 
130  4) Code significantly slimmer at run-time than V1.0.
131 
132 
133 GENERAL
134 =======
135 
136  1) The C preprocessor symbol to have the clock built has been changed
137     from ARC to ARCRON_MSF to CLOCK_ARCRON_MSF to minimise the
138     possiblity of clashes with other symbols in the future.
139 
140  2) PRECISION should be -4/-5 (63ms/31ms) for the following reasons:
141 
142      a) The ARC documentation claims the internal clock is (only)
143 	accurate to about 20ms relative to Rugby (plus there must be
144 	noticable drift and delay in the ms range due to transmission
145 	delays and changing atmospheric effects).  This clock is not
146 	designed for ms accuracy as NTP has spoilt us all to expect.
147 
148      b) The clock oscillator looks like a simple uncompensated quartz
149 	crystal of the sort used in digital watches (ie 32768Hz) which
150 	can have large temperature coefficients and drifts; it is not
151 	clear if this oscillator is properly disciplined to the MSF
152 	transmission, but as the default is to resync only once per
153 	*day*, we can imagine that it is not, and is free-running.  We
154 	can minimise drift by resyncing more often (at the cost of
155 	reduced battery life), but drift/wander may still be
156 	significant.
157 
158      c) Note that the bit time of 3.3ms adds to the potential error in
159 	the the clock timestamp, since the bit clock of the serial link
160 	may effectively be free-running with respect to the host clock
161 	and the MSF clock.  Actually, the error is probably 1/16th of
162 	the above, since the input data is probably sampled at at least
163 	16x the bit rate.
164 
165     By keeping the clock marked as not very precise, it will have a
166     fairly large dispersion, and thus will tend to be used as a
167     `backup' time source and sanity checker, which this clock is
168     probably ideal for.  For an isolated network without other time
169     sources, this clock can probably be expected to provide *much*
170     better than 1s accuracy, which will be fine.
171 
172     By default, PRECISION is set to -4, but experience, especially at a
173     particular geographic location with a particular clock, may allow
174     this to be altered to -5.  (Note that skews of +/- 10ms are to be
175     expected from the clock from time-to-time.)  This improvement of
176     reported precision can be instigated by setting flag3 to 1, though
177     the PRECISION will revert to the normal value while the clock
178     signal quality is unknown whatever the flag3 setting.
179 
180     IN ANY CASE, BE SURE TO SET AN APPROPRIATE FUDGE FACTOR TO REMOVE
181     ANY RESIDUAL SKEW, eg:
182 
183 	server 127.127.27.0 # ARCRON MSF radio clock unit 0.
184 	# Fudge timestamps by about 20ms.
185 	fudge 127.127.27.0 time1 0.020
186 
187     You will need to observe your system's behaviour, assuming you have
188     some other NTP source to compare it with, to work out what the
189     fudge factor should be.  For my Sun SS1 running SunOS 4.1.3_U1 with
190     my MSF clock with my distance from the MSF transmitter, +20ms
191     seemed about right, after some observation.
192 
193  3) REFID has been made "MSFa" to reflect the MSF time source and the
194     ARCRON receiver.
195 
196  4) DEFAULT_RESYNC_TIME is the time in seconds (by default) before
197     forcing a resync since the last attempt.  This is picked to give a
198     little less than an hour between resyncs and to try to avoid
199     clashing with any regular event at a regular time-past-the-hour
200     which might cause systematic errors.
201 
202     The INITIAL_RESYNC_DELAY is to avoid bothering the clock and
203     running down its batteries unnecesarily if ntpd is going to crash
204     or be killed or reconfigured quickly.  If ARCRON_KEEN is defined
205     then this period is long enough for (with normal polling rates)
206     enough time samples to have been taken to allow ntpd to sync to
207     the clock before the interruption for the clock to resync to MSF.
208     This avoids ntpd syncing to another peer first and then
209     almost immediately hopping to the MSF clock.
210 
211     The RETRY_RESYNC_TIME is used before rescheduling a resync after a
212     resync failed to reveal a statisfatory signal quality (too low or
213     unknown).
214 
215  5) The clock seems quite jittery, so I have increased the
216     median-filter size from the typical (previous) value of 3.  I
217     discard up to half the results in the filter.  It looks like maybe
218     1 sample in 10 or so (maybe less) is a spike, so allow the median
219     filter to discard at least 10% of its entries or 1 entry, whichever
220     is greater.
221 
222  6) Sleeping *before* each character sent to the unit to allow required
223     inter-character time but without introducting jitter and delay in
224     handling the response if possible.
225 
226  7) If the flag ARCRON_KEEN is defined, take time samples whenever
227     possible, even while resyncing, etc.  We rely, in this case, on the
228     clock always giving us a reasonable time or else telling us in the
229     status byte at the end of the timestamp that it failed to sync to
230     MSF---thus we should never end up syncing to completely the wrong
231     time.
232 
233  8) If the flag ARCRON_OWN_FILTER is defined, use own versions of
234     refclock median-filter routines to get round small bug in 3-5.90
235     code which does not return the median offset. XXX Removed this
236     bit due NTP Version 4 upgrade - dlm.
237 
238  9) We would appear to have a year-2000 problem with this clock since
239     it returns only the two least-significant digits of the year.  But
240     ntpd ignores the year and uses the local-system year instead, so
241     this is in fact not a problem.  Nevertheless, we attempt to do a
242     sensible thing with the dates, wrapping them into a 100-year
243     window.
244 
245  10)Logs stats information that can be used by Derek's Tcl/Tk utility
246     to show the status of the clock.
247 
248  11)The clock documentation insists that the number of bits per
249     character to be sent to the clock, and sent by it, is 11, including
250     one start bit and two stop bits.  The data format is either 7+even
251     or 8+none.
252 
253 
254 TO-DO LIST
255 ==========
256 
257   * Eliminate use of scanf(), and maybe sprintf().
258 
259   * Allow user setting of resync interval to trade battery life for
260     accuracy; maybe could be done via fudge factor or unit number.
261 
262   * Possibly note the time since the last resync of the MSF clock to
263     MSF as the age of the last reference timestamp, ie trust the
264     clock's oscillator not very much...
265 
266   * Add very slow auto-adjustment up to a value of +/- time2 to correct
267     for long-term errors in the clock value (time2 defaults to 0 so the
268     correction would be disabled by default).
269 
270   * Consider trying to use the tty_clk/ppsclock support.
271 
272   * Possibly use average or maximum signal quality reported during
273     resync, rather than just the last one, which may be atypical.
274 
275 */
276 
277 
278 /* Notes for HKW Elektronik GmBH Radio clock driver */
279 /* Author Lyndon David, Sentinet Ltd, Feb 1997      */
280 /* These notes seem also to apply usefully to the ARCRON clock. */
281 
282 /* The HKW clock module is a radio receiver tuned into the Rugby */
283 /* MSF time signal tranmitted on 60 kHz. The clock module connects */
284 /* to the computer via a serial line and transmits the time encoded */
285 /* in 15 bytes at 300 baud 7 bits two stop bits even parity */
286 
287 /* Clock communications, from the datasheet */
288 /* All characters sent to the clock are echoed back to the controlling */
289 /* device. */
290 /* Transmit time/date information */
291 /* syntax ASCII o<cr> */
292 /* Character o may be replaced if neccesary by a character whose code */
293 /* contains the lowest four bits f(hex) eg */
294 /* syntax binary: xxxx1111 00001101 */
295 
296 /* DHD note:
297 You have to wait for character echo + 10ms before sending next character.
298 */
299 
300 /* The clock replies to this command with a sequence of 15 characters */
301 /* which contain the complete time and a final <cr> making 16 characters */
302 /* in total. */
303 /* The RC computer clock will not reply immediately to this command because */
304 /* the start bit edge of the first reply character marks the beginning of */
305 /* the second. So the RC Computer Clock will reply to this command at the */
306 /* start of the next second */
307 /* The characters have the following meaning */
308 /* 1. hours tens   */
309 /* 2. hours units  */
310 /* 3. minutes tens */
311 /* 4. minutes units */
312 /* 5. seconds tens  */
313 /* 6. seconds units */
314 /* 7. day of week 1-monday 7-sunday */
315 /* 8. day of month tens */
316 /* 9. day of month units */
317 /* 10. month tens */
318 /* 11. month units */
319 /* 12. year tens */
320 /* 13. year units */
321 /* 14. BST/UTC status */
322 /*	bit 7	parity */
323 /*	bit 6	always 0 */
324 /*	bit 5	always 1 */
325 /*	bit 4	always 1 */
326 /*	bit 3	always 0 */
327 /*	bit 2	=1 if UTC is in effect, complementary to the BST bit */
328 /*	bit 1	=1 if BST is in effect, according to the BST bit     */
329 /*	bit 0	BST/UTC change impending bit=1 in case of change impending */
330 /* 15. status */
331 /*	bit 7	parity */
332 /*	bit 6	always 0 */
333 /*	bit 5	always 1 */
334 /*	bit 4	always 1 */
335 /*	bit 3	=1 if low battery is detected */
336 /*	bit 2	=1 if the very last reception attempt failed and a valid */
337 /*		time information already exists (bit0=1) */
338 /*		=0 if the last reception attempt was successful */
339 /*	bit 1	=1 if at least one reception since 2:30 am was successful */
340 /*		=0 if no reception attempt since 2:30 am was successful */
341 /*	bit 0	=1 if the RC Computer Clock contains valid time information */
342 /*		This bit is zero after reset and one after the first */
343 /*		successful reception attempt */
344 
345 /* DHD note:
346 Also note g<cr> command which confirms that a resync is in progress, and
347 if so what signal quality (0--5) is available.
348 Also note h<cr> command which starts a resync to MSF signal.
349 */
350 
351 
352 #include "ntpd.h"
353 #include "ntp_io.h"
354 #include "ntp_refclock.h"
355 #include "ntp_calendar.h"
356 #include "ntp_stdlib.h"
357 
358 #include <stdio.h>
359 #include <ctype.h>
360 
361 #if defined(HAVE_BSD_TTYS)
362 #include <sgtty.h>
363 #endif /* HAVE_BSD_TTYS */
364 
365 #if defined(HAVE_SYSV_TTYS)
366 #include <termio.h>
367 #endif /* HAVE_SYSV_TTYS */
368 
369 #if defined(HAVE_TERMIOS)
370 #include <termios.h>
371 #endif
372 
373 /*
374  * This driver supports the ARCRON MSF/DCF/WWVB Radio Controlled Clock
375  */
376 
377 /*
378  * Interface definitions
379  */
380 #define DEVICE		"/dev/arc%d"	/* Device name and unit. */
381 #define SPEED		B300		/* UART speed (300 baud) */
382 #define PRECISION	(-4)		/* Precision  (~63 ms). */
383 #define HIGHPRECISION	(-5)		/* If things are going well... */
384 #define REFID		"MSFa"		/* Reference ID. */
385 #define REFID_MSF	"MSF"		/* Reference ID. */
386 #define REFID_DCF77	"DCF"		/* Reference ID. */
387 #define REFID_WWVB	"WWVB"		/* Reference ID. */
388 #define DESCRIPTION	"ARCRON MSF/DCF/WWVB Receiver"
389 
390 #ifdef PRE_NTP420
391 #define MODE ttlmax
392 #else
393 #define MODE ttl
394 #endif
395 
396 #define LENARC		16		/* Format `o' timecode length. */
397 
398 #define BITSPERCHAR	11		/* Bits per character. */
399 #define BITTIME		0x0DA740E	/* Time for 1 bit at 300bps. */
400 #define CHARTIME10	0x8888888	/* Time for 10-bit char at 300bps. */
401 #define CHARTIME11	0x962FC96	/* Time for 11-bit char at 300bps. */
402 #define CHARTIME			/* Time for char at 300bps. */ \
403 ( (BITSPERCHAR == 11) ? CHARTIME11 : ( (BITSPERCHAR == 10) ? CHARTIME10 : \
404 				       (BITSPERCHAR * BITTIME) ) )
405 
406      /* Allow for UART to accept char half-way through final stop bit. */
407 #define INITIALOFFSET (u_int32)(-BITTIME/2)
408 
409      /*
410     charoffsets[x] is the time after the start of the second that byte
411     x (with the first byte being byte 1) is received by the UART,
412     assuming that the initial edge of the start bit of the first byte
413     is on-time.  The values are represented as the fractional part of
414     an l_fp.
415 
416     We store enough values to have the offset of each byte including
417     the trailing \r, on the assumption that the bytes follow one
418     another without gaps.
419     */
420      static const u_int32 charoffsets[LENARC+1] = {
421 #if BITSPERCHAR == 11 /* Usual case. */
422 	     /* Offsets computed as accurately as possible... */
423 	     0,
424 	     INITIALOFFSET + 0x0962fc96, /*  1 chars,  11 bits */
425 	     INITIALOFFSET + 0x12c5f92c, /*  2 chars,  22 bits */
426 	     INITIALOFFSET + 0x1c28f5c3, /*  3 chars,  33 bits */
427 	     INITIALOFFSET + 0x258bf259, /*  4 chars,  44 bits */
428 	     INITIALOFFSET + 0x2eeeeeef, /*  5 chars,  55 bits */
429 	     INITIALOFFSET + 0x3851eb85, /*  6 chars,  66 bits */
430 	     INITIALOFFSET + 0x41b4e81b, /*  7 chars,  77 bits */
431 	     INITIALOFFSET + 0x4b17e4b1, /*  8 chars,  88 bits */
432 	     INITIALOFFSET + 0x547ae148, /*  9 chars,  99 bits */
433 	     INITIALOFFSET + 0x5dddddde, /* 10 chars, 110 bits */
434 	     INITIALOFFSET + 0x6740da74, /* 11 chars, 121 bits */
435 	     INITIALOFFSET + 0x70a3d70a, /* 12 chars, 132 bits */
436 	     INITIALOFFSET + 0x7a06d3a0, /* 13 chars, 143 bits */
437 	     INITIALOFFSET + 0x8369d037, /* 14 chars, 154 bits */
438 	     INITIALOFFSET + 0x8ccccccd, /* 15 chars, 165 bits */
439 	     INITIALOFFSET + 0x962fc963  /* 16 chars, 176 bits */
440 #else
441 	     /* Offsets computed with a small rounding error... */
442 	     0,
443 	     INITIALOFFSET +  1 * CHARTIME,
444 	     INITIALOFFSET +  2 * CHARTIME,
445 	     INITIALOFFSET +  3 * CHARTIME,
446 	     INITIALOFFSET +  4 * CHARTIME,
447 	     INITIALOFFSET +  5 * CHARTIME,
448 	     INITIALOFFSET +  6 * CHARTIME,
449 	     INITIALOFFSET +  7 * CHARTIME,
450 	     INITIALOFFSET +  8 * CHARTIME,
451 	     INITIALOFFSET +  9 * CHARTIME,
452 	     INITIALOFFSET + 10 * CHARTIME,
453 	     INITIALOFFSET + 11 * CHARTIME,
454 	     INITIALOFFSET + 12 * CHARTIME,
455 	     INITIALOFFSET + 13 * CHARTIME,
456 	     INITIALOFFSET + 14 * CHARTIME,
457 	     INITIALOFFSET + 15 * CHARTIME,
458 	     INITIALOFFSET + 16 * CHARTIME
459 #endif
460      };
461 
462 #define DEFAULT_RESYNC_TIME  (57*60)	/* Gap between resync attempts (s). */
463 #define RETRY_RESYNC_TIME    (27*60)	/* Gap to emergency resync attempt. */
464 #ifdef ARCRON_KEEN
465 #define INITIAL_RESYNC_DELAY 500	/* Delay before first resync. */
466 #else
467 #define INITIAL_RESYNC_DELAY 50		/* Delay before first resync. */
468 #endif
469 
470      static const int moff[12] =
471 { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 };
472 /* Flags for a raw open() of the clock serial device. */
473 #ifdef O_NOCTTY /* Good, we can avoid tty becoming controlling tty. */
474 #define OPEN_FLAGS (O_RDWR | O_NOCTTY)
475 #else		/* Oh well, it may not matter... */
476 #define OPEN_FLAGS (O_RDWR)
477 #endif
478 
479 
480 /* Length of queue of command bytes to be sent. */
481 #define CMDQUEUELEN 4			/* Enough for two cmds + each \r. */
482 /* Queue tick time; interval in seconds between chars taken off queue. */
483 /* Must be >= 2 to allow o\r response to come back uninterrupted. */
484 #define QUEUETICK   2			/* Allow o\r reply to finish. */
485 
486 /*
487  * ARC unit control structure
488  */
489 struct arcunit {
490 	l_fp lastrec;	    /* Time tag for the receive time (system). */
491 	int status;	    /* Clock status. */
492 
493 	int quality;	    /* Quality of reception 0--5 for unit. */
494 	/* We may also use the values -1 or 6 internally. */
495 	u_long quality_stamp; /* Next time to reset quality average. */
496 
497 	u_long next_resync; /* Next resync time (s) compared to current_time. */
498 	int resyncing;	    /* Resync in progress if true. */
499 
500 	/* In the outgoing queue, cmdqueue[0] is next to be sent. */
501 	char cmdqueue[CMDQUEUELEN+1]; /* Queue of outgoing commands + \0. */
502 
503 	u_long saved_flags; /* Saved fudge flags. */
504 };
505 
506 #ifdef ARCRON_LEAPSECOND_KEEN
507 /* The flag `possible_leap' is set non-zero when any MSF unit
508        thinks a leap-second may have happened.
509 
510        Set whenever we receive a valid time sample in the first hour of
511        the first day of the first/seventh months.
512 
513        Outside the special hour this value is unconditionally set
514        to zero by the receive routine.
515 
516        On finding itself in this timeslot, as long as the value is
517        non-negative, the receive routine sets it to a positive value to
518        indicate a resync to MSF should be performed.
519 
520        In the poll routine, if this value is positive and we are not
521        already resyncing (eg from a sync that started just before
522        midnight), start resyncing and set this value negative to
523        indicate that a leap-triggered resync has been started.  Having
524        set this negative prevents the receive routine setting it
525        positive and thus prevents multiple resyncs during the witching
526        hour.
527      */
528 static int possible_leap = 0;       /* No resync required by default. */
529 #endif
530 
531 #if 0
532 static void dummy_event_handler (struct peer *);
533 static void   arc_event_handler (struct peer *);
534 #endif /* 0 */
535 
536 #define QUALITY_UNKNOWN	    -1 /* Indicates unknown clock quality. */
537 #define MIN_CLOCK_QUALITY    0 /* Min quality clock will return. */
538 #define MIN_CLOCK_QUALITY_OK 3 /* Min quality for OK reception. */
539 #define MAX_CLOCK_QUALITY    5 /* Max quality clock will return. */
540 
541 /*
542  * Function prototypes
543  */
544 static	int	arc_start	(int, struct peer *);
545 static	void	arc_shutdown	(int, struct peer *);
546 static	void	arc_receive	(struct recvbuf *);
547 static	void	arc_poll	(int, struct peer *);
548 
549 /*
550  * Transfer vector
551  */
552 struct  refclock refclock_arc = {
553 	arc_start,		/* start up driver */
554 	arc_shutdown,		/* shut down driver */
555 	arc_poll,		/* transmit poll message */
556 	noentry,		/* not used (old arc_control) */
557 	noentry,		/* initialize driver (not used) */
558 	noentry,		/* not used (old arc_buginfo) */
559 	NOFLAGS			/* not used */
560 };
561 
562 /* Queue us up for the next tick. */
563 #define ENQUEUE(up) \
564 	do { \
565 	     peer->nextaction = current_time + QUEUETICK; \
566 	} while(0)
567 
568 /* Placeholder event handler---does nothing safely---soaks up loose tick. */
569 static void
570 dummy_event_handler(
571 	struct peer *peer
572 	)
573 {
574 #ifdef DEBUG
575 	if(debug) { printf("arc: dummy_event_handler() called.\n"); }
576 #endif
577 }
578 
579 /*
580 Normal event handler.
581 
582 Take first character off queue and send to clock if not a null.
583 
584 Shift characters down and put a null on the end.
585 
586 We assume that there is no parallelism so no race condition, but even
587 if there is nothing bad will happen except that we might send some bad
588 data to the clock once in a while.
589 */
590 static void
591 arc_event_handler(
592 	struct peer *peer
593 	)
594 {
595 	struct refclockproc *pp = peer->procptr;
596 	register struct arcunit *up = pp->unitptr;
597 	int i;
598 	char c;
599 #ifdef DEBUG
600 	if(debug > 2) { printf("arc: arc_event_handler() called.\n"); }
601 #endif
602 
603 	c = up->cmdqueue[0];       /* Next char to be sent. */
604 	/* Shift down characters, shifting trailing \0 in at end. */
605 	for(i = 0; i < CMDQUEUELEN; ++i)
606 	{ up->cmdqueue[i] = up->cmdqueue[i+1]; }
607 
608 	/* Don't send '\0' characters. */
609 	if(c != '\0') {
610 		if(write(pp->io.fd, &c, 1) != 1) {
611 			msyslog(LOG_NOTICE, "ARCRON: write to fd %d failed", pp->io.fd);
612 		}
613 #ifdef DEBUG
614 		else if(debug) { printf("arc: sent `%2.2x', fd %d.\n", c, pp->io.fd); }
615 #endif
616 	}
617 
618 	ENQUEUE(up);
619 }
620 
621 /*
622  * arc_start - open the devices and initialize data for processing
623  */
624 static int
625 arc_start(
626 	int unit,
627 	struct peer *peer
628 	)
629 {
630 	register struct arcunit *up;
631 	struct refclockproc *pp;
632 	int temp_fd;
633 	int fd;
634 	char device[20];
635 #ifdef HAVE_TERMIOS
636 	struct termios arg;
637 #endif
638 
639 	msyslog(LOG_NOTICE, "MSF_ARCRON %s: opening unit %d",
640 		arc_version, unit);
641 	DPRINTF(1, ("arc: %s: attempt to open unit %d.\n", arc_version,
642 		unit));
643 
644 	/*
645 	 * Open serial port. Use CLK line discipline, if available.
646 	 */
647 	snprintf(device, sizeof(device), DEVICE, unit);
648 	temp_fd = refclock_open(device, SPEED, LDISC_CLK);
649 	if (temp_fd <= 0)
650 		return 0;
651 	DPRINTF(1, ("arc: unit %d using tty_open().\n", unit));
652 	fd = tty_open(device, OPEN_FLAGS, 0777);
653 	if (fd < 0) {
654 		msyslog(LOG_ERR, "MSF_ARCRON(%d): failed second open(%s, 0777): %m.\n",
655 			unit, device);
656 		close(temp_fd);
657 		return 0;
658 	}
659 	close(temp_fd);
660 	temp_fd = -1;
661 
662 #ifndef SYS_WINNT
663 	fcntl(fd, F_SETFL, 0); /* clear the descriptor flags */
664 #endif
665 	DPRINTF(1, ("arc: opened RS232 port with file descriptor %d.\n", fd));
666 
667 #ifdef HAVE_TERMIOS
668 
669 	if (tcgetattr(fd, &arg) < 0) {
670 		msyslog(LOG_ERR, "MSF_ARCRON(%d): tcgetattr(%s): %m.\n",
671 			unit, device);
672 		close(fd);
673 		return 0;
674 	}
675 
676 	arg.c_iflag = IGNBRK | ISTRIP;
677 	arg.c_oflag = 0;
678 	arg.c_cflag = B300 | CS8 | CREAD | CLOCAL | CSTOPB;
679 	arg.c_lflag = 0;
680 	arg.c_cc[VMIN] = 1;
681 	arg.c_cc[VTIME] = 0;
682 
683 	if (tcsetattr(fd, TCSANOW, &arg) < 0) {
684 		msyslog(LOG_ERR, "MSF_ARCRON(%d): tcsetattr(%s): %m.\n",
685 			unit, device);
686 		close(fd);
687 		return 0;
688 	}
689 
690 #else
691 
692 	msyslog(LOG_ERR, "ARCRON: termios required by this driver");
693 	(void)close(fd);
694 
695 	return 0;
696 
697 #endif
698 
699 	/* Set structure to all zeros... */
700 	up = emalloc_zero(sizeof(*up));
701 	pp = peer->procptr;
702 	pp->io.clock_recv = arc_receive;
703 	pp->io.srcclock = (caddr_t)peer;
704 	pp->io.datalen = 0;
705 	pp->io.fd = fd;
706 	if (!io_addclock(&pp->io)) {
707 		close(fd);
708 		pp->io.fd = -1;
709 		free(up);
710 		return(0);
711 	}
712 	pp->unitptr = up;
713 
714 	/*
715 	 * Initialize miscellaneous variables
716 	 */
717 	peer->precision = PRECISION;
718 	peer->stratum = 2;              /* Default to stratum 2 not 0. */
719 	pp->clockdesc = DESCRIPTION;
720 	if (peer->MODE > 3) {
721 		msyslog(LOG_NOTICE, "ARCRON: Invalid mode %d", peer->MODE);
722 		return 0;
723 	}
724 #ifdef DEBUG
725 	if(debug) { printf("arc: mode = %d.\n", peer->MODE); }
726 #endif
727 	switch (peer->MODE) {
728 	    case 1:
729 		memcpy((char *)&pp->refid, REFID_MSF, 4);
730 		break;
731 	    case 2:
732 		memcpy((char *)&pp->refid, REFID_DCF77, 4);
733 		break;
734 	    case 3:
735 		memcpy((char *)&pp->refid, REFID_WWVB, 4);
736 		break;
737 	    default:
738 		memcpy((char *)&pp->refid, REFID, 4);
739 		break;
740 	}
741 	/* Spread out resyncs so that they should remain separated. */
742 	up->next_resync = current_time + INITIAL_RESYNC_DELAY + (67*unit)%1009;
743 
744 #if 0 /* Not needed because of zeroing of arcunit structure... */
745 	up->resyncing = 0;              /* Not resyncing yet. */
746 	up->saved_flags = 0;            /* Default is all flags off. */
747 	/* Clear send buffer out... */
748 	{
749 		int i;
750 		for(i = CMDQUEUELEN; i >= 0; --i) { up->cmdqueue[i] = '\0'; }
751 	}
752 #endif
753 
754 #ifdef ARCRON_KEEN
755 	up->quality = QUALITY_UNKNOWN;  /* Trust the clock immediately. */
756 #else
757 	up->quality = MIN_CLOCK_QUALITY;/* Don't trust the clock yet. */
758 #endif
759 
760 	peer->action = arc_event_handler;
761 
762 	ENQUEUE(up);
763 
764 	return(1);
765 }
766 
767 
768 /*
769  * arc_shutdown - shut down the clock
770  */
771 static void
772 arc_shutdown(
773 	int unit,
774 	struct peer *peer
775 	)
776 {
777 	register struct arcunit *up;
778 	struct refclockproc *pp;
779 
780 	peer->action = dummy_event_handler;
781 
782 	pp = peer->procptr;
783 	up = pp->unitptr;
784 	if (-1 != pp->io.fd)
785 		io_closeclock(&pp->io);
786 	if (NULL != up)
787 		free(up);
788 }
789 
790 /*
791 Compute space left in output buffer.
792 */
793 static int
794 space_left(
795 	register struct arcunit *up
796 	)
797 {
798 	int spaceleft;
799 
800 	/* Compute space left in buffer after any pending output. */
801 	for(spaceleft = 0; spaceleft < CMDQUEUELEN; ++spaceleft)
802 	{ if(up->cmdqueue[CMDQUEUELEN - 1 - spaceleft] != '\0') { break; } }
803 	return(spaceleft);
804 }
805 
806 /*
807 Send command by copying into command buffer as far forward as possible,
808 after any pending output.
809 
810 Indicate an error by returning 0 if there is not space for the command.
811 */
812 static int
813 send_slow(
814 	register struct arcunit *up,
815 	int fd,
816 	const char *s
817 	)
818 {
819 	int sl = strlen(s);
820 	int spaceleft = space_left(up);
821 
822 #ifdef DEBUG
823 	if(debug > 1) { printf("arc: spaceleft = %d.\n", spaceleft); }
824 #endif
825 	if(spaceleft < sl) { /* Should not normally happen... */
826 #ifdef DEBUG
827 		msyslog(LOG_NOTICE, "ARCRON: send-buffer overrun (%d/%d)",
828 			sl, spaceleft);
829 #endif
830 		return(0);			/* FAILED! */
831 	}
832 
833 	/* Copy in the command to be sent. */
834 	while(*s && spaceleft > 0) { up->cmdqueue[CMDQUEUELEN - spaceleft--] = *s++; }
835 
836 	return(1);
837 }
838 
839 
840 static int
841 get2(char *p, int *val)
842 {
843   if (!isdigit((unsigned char)p[0]) || !isdigit((unsigned char)p[1])) return 0;
844   *val = (p[0] - '0') * 10 + p[1] - '0';
845   return 1;
846 }
847 
848 static int
849 get1(char *p, int *val)
850 {
851   if (!isdigit((unsigned char)p[0])) return 0;
852   *val = p[0] - '0';
853   return 1;
854 }
855 
856 /* Macro indicating action we will take for different quality values. */
857 #define quality_action(q) \
858 (((q) == QUALITY_UNKNOWN) ?         "UNKNOWN, will use clock anyway" : \
859  (((q) < MIN_CLOCK_QUALITY_OK) ? "TOO POOR, will not use clock" : \
860   "OK, will use clock"))
861 
862 /*
863  * arc_receive - receive data from the serial interface
864  */
865 static void
866 arc_receive(
867 	struct recvbuf *rbufp
868 	)
869 {
870 	register struct arcunit *up;
871 	struct refclockproc *pp;
872 	struct peer *peer;
873 	char c;
874 	int i, n, wday, month, flags, status;
875 	int arc_last_offset;
876 	static int quality_average = 0;
877 	static int quality_sum = 0;
878 	static int quality_polls = 0;
879 
880 	/*
881 	 * Initialize pointers and read the timecode and timestamp
882 	 */
883 	peer = (struct peer *)rbufp->recv_srcclock;
884 	pp = peer->procptr;
885 	up = pp->unitptr;
886 
887 
888 	/*
889 	  If the command buffer is empty, and we are resyncing, insert a
890 	  g\r quality request into it to poll for signal quality again.
891 	*/
892 	if((up->resyncing) && (space_left(up) == CMDQUEUELEN)) {
893 #ifdef DEBUG
894 		if(debug > 1) { printf("arc: inserting signal-quality poll.\n"); }
895 #endif
896 		send_slow(up, pp->io.fd, "g\r");
897 	}
898 
899 	/*
900 	  The `arc_last_offset' is the offset in lastcode[] of the last byte
901 	  received, and which we assume actually received the input
902 	  timestamp.
903 
904 	  (When we get round to using tty_clk and it is available, we
905 	  assume that we will receive the whole timecode with the
906 	  trailing \r, and that that \r will be timestamped.  But this
907 	  assumption also works if receive the characters one-by-one.)
908 	*/
909 	arc_last_offset = pp->lencode+rbufp->recv_length - 1;
910 
911 	/*
912 	  We catch a timestamp iff:
913 
914 	  * The command code is `o' for a timestamp.
915 
916 	  * If ARCRON_MULTIPLE_SAMPLES is undefined then we must have
917 	  exactly char in the buffer (the command code) so that we
918 	  only sample the first character of the timecode as our
919 	  `on-time' character.
920 
921 	  * The first character in the buffer is not the echoed `\r'
922 	  from the `o` command (so if we are to timestamp an `\r' it
923 	  must not be first in the receive buffer with lencode==1.
924 	  (Even if we had other characters following it, we probably
925 	  would have a premature timestamp on the '\r'.)
926 
927 	  * We have received at least one character (I cannot imagine
928 	  how it could be otherwise, but anyway...).
929 	*/
930 	c = rbufp->recv_buffer[0];
931 	if((pp->a_lastcode[0] == 'o') &&
932 #ifndef ARCRON_MULTIPLE_SAMPLES
933 	   (pp->lencode == 1) &&
934 #endif
935 	   ((pp->lencode != 1) || (c != '\r')) &&
936 	   (arc_last_offset >= 1)) {
937 		/* Note that the timestamp should be corrected if >1 char rcvd. */
938 		l_fp timestamp;
939 		timestamp = rbufp->recv_time;
940 #ifdef DEBUG
941 		if(debug) { /* Show \r as `R', other non-printing char as `?'. */
942 			printf("arc: stamp -->%c<-- (%d chars rcvd)\n",
943 			       ((c == '\r') ? 'R' : (isgraph((unsigned char)c) ? c : '?')),
944 			       rbufp->recv_length);
945 		}
946 #endif
947 
948 		/*
949 		  Now correct timestamp by offset of last byte received---we
950 		  subtract from the receive time the delay implied by the
951 		  extra characters received.
952 
953 		  Reject the input if the resulting code is too long, but
954 		  allow for the trailing \r, normally not used but a good
955 		  handle for tty_clk or somesuch kernel timestamper.
956 		*/
957 		if(arc_last_offset > LENARC) {
958 #ifdef DEBUG
959 			if(debug) {
960 				printf("arc: input code too long (%d cf %d); rejected.\n",
961 				       arc_last_offset, LENARC);
962 			}
963 #endif
964 			pp->lencode = 0;
965 			refclock_report(peer, CEVNT_BADREPLY);
966 			return;
967 		}
968 
969 		L_SUBUF(&timestamp, charoffsets[arc_last_offset]);
970 #ifdef DEBUG
971 		if(debug > 1) {
972 			printf(
973 				"arc: %s%d char(s) rcvd, the last for lastcode[%d]; -%sms offset applied.\n",
974 				((rbufp->recv_length > 1) ? "*** " : ""),
975 				rbufp->recv_length,
976 				arc_last_offset,
977 				mfptoms((unsigned long)0,
978 					charoffsets[arc_last_offset],
979 					1));
980 		}
981 #endif
982 
983 #ifdef ARCRON_MULTIPLE_SAMPLES
984 		/*
985 		  If taking multiple samples, capture the current adjusted
986 		  sample iff:
987 
988 		  * No timestamp has yet been captured (it is zero), OR
989 
990 		  * This adjusted timestamp is earlier than the one already
991 		  captured, on the grounds that this one suffered less
992 		  delay in being delivered to us and is more accurate.
993 
994 		*/
995 		if(L_ISZERO(&(up->lastrec)) ||
996 		   L_ISGEQ(&(up->lastrec), &timestamp))
997 #endif
998 		{
999 #ifdef DEBUG
1000 			if(debug > 1) {
1001 				printf("arc: system timestamp captured.\n");
1002 #ifdef ARCRON_MULTIPLE_SAMPLES
1003 				if(!L_ISZERO(&(up->lastrec))) {
1004 					l_fp diff;
1005 					diff = up->lastrec;
1006 					L_SUB(&diff, &timestamp);
1007 					printf("arc: adjusted timestamp by -%sms.\n",
1008 					       mfptoms(diff.l_i, diff.l_f, 3));
1009 				}
1010 #endif
1011 			}
1012 #endif
1013 			up->lastrec = timestamp;
1014 		}
1015 
1016 	}
1017 
1018 	/* Just in case we still have lots of rubbish in the buffer... */
1019 	/* ...and to avoid the same timestamp being reused by mistake, */
1020 	/* eg on receipt of the \r coming in on its own after the      */
1021 	/* timecode.						       */
1022 	if(pp->lencode >= LENARC) {
1023 #ifdef DEBUG
1024 		if(debug && (rbufp->recv_buffer[0] != '\r'))
1025 		{ printf("arc: rubbish in pp->a_lastcode[].\n"); }
1026 #endif
1027 		pp->lencode = 0;
1028 		return;
1029 	}
1030 
1031 	/* Append input to code buffer, avoiding overflow. */
1032 	for(i = 0; i < rbufp->recv_length; i++) {
1033 		if(pp->lencode >= LENARC) { break; } /* Avoid overflow... */
1034 		c = rbufp->recv_buffer[i];
1035 
1036 		/* Drop trailing '\r's and drop `h' command echo totally. */
1037 		if(c != '\r' && c != 'h') { pp->a_lastcode[pp->lencode++] = c; }
1038 
1039 		/*
1040 		  If we've just put an `o' in the lastcode[0], clear the
1041 		  timestamp in anticipation of a timecode arriving soon.
1042 
1043 		  We would expect to get to process this before any of the
1044 		  timecode arrives.
1045 		*/
1046 		if((c == 'o') && (pp->lencode == 1)) {
1047 			L_CLR(&(up->lastrec));
1048 #ifdef DEBUG
1049 			if(debug > 1) { printf("arc: clearing timestamp.\n"); }
1050 #endif
1051 		}
1052 	}
1053 	if (pp->lencode == 0) return;
1054 
1055 	/* Handle a quality message. */
1056 	if(pp->a_lastcode[0] == 'g') {
1057 		int r, q;
1058 
1059 		if(pp->lencode < 3) { return; } /* Need more data... */
1060 		r = (pp->a_lastcode[1] & 0x7f); /* Strip parity. */
1061 		q = (pp->a_lastcode[2] & 0x7f); /* Strip parity. */
1062 		if(((q & 0x70) != 0x30) || ((q & 0xf) > MAX_CLOCK_QUALITY) ||
1063 		   ((r & 0x70) != 0x30)) {
1064 			/* Badly formatted response. */
1065 #ifdef DEBUG
1066 			if(debug) { printf("arc: bad `g' response %2x %2x.\n", r, q); }
1067 #endif
1068 			return;
1069 		}
1070 		if(r == '3') { /* Only use quality value whilst sync in progress. */
1071 			if (up->quality_stamp < current_time) {
1072 				struct calendar cal;
1073 				l_fp new_stamp;
1074 
1075 				get_systime (&new_stamp);
1076 				caljulian (new_stamp.l_ui, &cal);
1077 				up->quality_stamp =
1078 					current_time + 60 - cal.second + 5;
1079 				quality_sum = 0;
1080 				quality_polls = 0;
1081 			}
1082 			quality_sum += (q & 0xf);
1083 			quality_polls++;
1084 			quality_average = (quality_sum / quality_polls);
1085 #ifdef DEBUG
1086 			if(debug) { printf("arc: signal quality %d (%d).\n", quality_average, (q & 0xf)); }
1087 #endif
1088 		} else if( /* (r == '2') && */ up->resyncing) {
1089 			up->quality = quality_average;
1090 #ifdef DEBUG
1091 			if(debug)
1092 			{
1093 				printf("arc: sync finished, signal quality %d: %s\n",
1094 				       up->quality,
1095 				       quality_action(up->quality));
1096 			}
1097 #endif
1098 			msyslog(LOG_NOTICE,
1099 				"ARCRON: sync finished, signal quality %d: %s",
1100 				up->quality,
1101 				quality_action(up->quality));
1102 			up->resyncing = 0; /* Resync is over. */
1103 			quality_average = 0;
1104 			quality_sum = 0;
1105 			quality_polls = 0;
1106 
1107 #ifdef ARCRON_KEEN
1108 			/* Clock quality dubious; resync earlier than usual. */
1109 			if((up->quality == QUALITY_UNKNOWN) ||
1110 			   (up->quality < MIN_CLOCK_QUALITY_OK))
1111 			{ up->next_resync = current_time + RETRY_RESYNC_TIME; }
1112 #endif
1113 		}
1114 		pp->lencode = 0;
1115 		return;
1116 	}
1117 
1118 	/* Stop now if this is not a timecode message. */
1119 	if(pp->a_lastcode[0] != 'o') {
1120 		pp->lencode = 0;
1121 		refclock_report(peer, CEVNT_BADREPLY);
1122 		return;
1123 	}
1124 
1125 	/* If we don't have enough data, wait for more... */
1126 	if(pp->lencode < LENARC) { return; }
1127 
1128 
1129 	/* WE HAVE NOW COLLECTED ONE TIMESTAMP (phew)... */
1130 #ifdef DEBUG
1131 	if(debug > 1) { printf("arc: NOW HAVE TIMESTAMP...\n"); }
1132 #endif
1133 
1134 	/* But check that we actually captured a system timestamp on it. */
1135 	if(L_ISZERO(&(up->lastrec))) {
1136 #ifdef DEBUG
1137 		if(debug) { printf("arc: FAILED TO GET SYSTEM TIMESTAMP\n"); }
1138 #endif
1139 		pp->lencode = 0;
1140 		refclock_report(peer, CEVNT_BADREPLY);
1141 		return;
1142 	}
1143 	/*
1144 	  Append a mark of the clock's received signal quality for the
1145 	  benefit of Derek Mulcahy's Tcl/Tk utility (we map the `unknown'
1146 	  quality value to `6' for his s/w) and terminate the string for
1147 	  sure.  This should not go off the buffer end.
1148 	*/
1149 	pp->a_lastcode[pp->lencode] = ((up->quality == QUALITY_UNKNOWN) ?
1150 				       '6' : ('0' + up->quality));
1151 	pp->a_lastcode[pp->lencode + 1] = '\0'; /* Terminate for printf(). */
1152 
1153 #ifdef PRE_NTP420
1154 	/* We don't use the micro-/milli- second part... */
1155 	pp->usec = 0;
1156 	pp->msec = 0;
1157 #else
1158 	/* We don't use the nano-second part... */
1159 	pp->nsec = 0;
1160 #endif
1161 	/* Validate format and numbers. */
1162 	if (pp->a_lastcode[0] != 'o'
1163 		|| !get2(pp->a_lastcode + 1, &pp->hour)
1164 		|| !get2(pp->a_lastcode + 3, &pp->minute)
1165 		|| !get2(pp->a_lastcode + 5, &pp->second)
1166 		|| !get1(pp->a_lastcode + 7, &wday)
1167 		|| !get2(pp->a_lastcode + 8, &pp->day)
1168 		|| !get2(pp->a_lastcode + 10, &month)
1169 		|| !get2(pp->a_lastcode + 12, &pp->year)) {
1170 #ifdef DEBUG
1171 		/* Would expect to have caught major problems already... */
1172 		if(debug) { printf("arc: badly formatted data.\n"); }
1173 #endif
1174 		pp->lencode = 0;
1175 		refclock_report(peer, CEVNT_BADREPLY);
1176 		return;
1177 	}
1178 	flags = pp->a_lastcode[14];
1179 	status = pp->a_lastcode[15];
1180 #ifdef DEBUG
1181 	if(debug) { printf("arc: status 0x%.2x flags 0x%.2x\n", flags, status); }
1182 #endif
1183 	n = 9;
1184 
1185 	/*
1186 	  Validate received values at least enough to prevent internal
1187 	  array-bounds problems, etc.
1188 	*/
1189 	if((pp->hour < 0) || (pp->hour > 23) ||
1190 	   (pp->minute < 0) || (pp->minute > 59) ||
1191 	   (pp->second < 0) || (pp->second > 60) /*Allow for leap seconds.*/ ||
1192 	   (wday < 1) || (wday > 7) ||
1193 	   (pp->day < 1) || (pp->day > 31) ||
1194 	   (month < 1) || (month > 12) ||
1195 	   (pp->year < 0) || (pp->year > 99)) {
1196 		/* Data out of range. */
1197 		pp->lencode = 0;
1198 		refclock_report(peer, CEVNT_BADREPLY);
1199 		return;
1200 	}
1201 
1202 
1203 	if(peer->MODE == 0) { /* compatiblity to original version */
1204 		int bst = flags;
1205 		/* Check that BST/UTC bits are the complement of one another. */
1206 		if(!(bst & 2) == !(bst & 4)) {
1207 			pp->lencode = 0;
1208 			refclock_report(peer, CEVNT_BADREPLY);
1209 			return;
1210 		}
1211 	}
1212 	if(status & 0x8) { msyslog(LOG_NOTICE, "ARCRON: battery low"); }
1213 
1214 	/* Year-2000 alert! */
1215 	/* Attempt to wrap 2-digit date into sensible window. */
1216 	if(pp->year < YEAR_PIVOT) { pp->year += 100; }		/* Y2KFixes */
1217 	pp->year += 1900;	/* use full four-digit year */	/* Y2KFixes */
1218 	/*
1219 	  Attempt to do the right thing by screaming that the code will
1220 	  soon break when we get to the end of its useful life.  What a
1221 	  hero I am...  PLEASE FIX LEAP-YEAR AND WRAP CODE IN 209X!
1222 	*/
1223 	if(pp->year >= YEAR_PIVOT+2000-2 ) {  			/* Y2KFixes */
1224 		/*This should get attention B^> */
1225 		msyslog(LOG_NOTICE,
1226 			"ARCRON: fix me!  EITHER YOUR DATE IS BADLY WRONG or else I will break soon!");
1227 	}
1228 #ifdef DEBUG
1229 	if(debug) {
1230 		printf("arc: n=%d %02d:%02d:%02d %02d/%02d/%04d %1d %1d\n",
1231 		       n,
1232 		       pp->hour, pp->minute, pp->second,
1233 		       pp->day, month, pp->year, flags, status);
1234 	}
1235 #endif
1236 
1237 	/*
1238 	  The status value tested for is not strictly supported by the
1239 	  clock spec since the value of bit 2 (0x4) is claimed to be
1240 	  undefined for MSF, yet does seem to indicate if the last resync
1241 	  was successful or not.
1242 	*/
1243 	pp->leap = LEAP_NOWARNING;
1244 	status &= 0x7;
1245 	if(status == 0x3) {
1246 		if(status != up->status)
1247 		{ msyslog(LOG_NOTICE, "ARCRON: signal acquired"); }
1248 	} else {
1249 		if(status != up->status) {
1250 			msyslog(LOG_NOTICE, "ARCRON: signal lost");
1251 			pp->leap = LEAP_NOTINSYNC; /* MSF clock is free-running. */
1252 			up->status = status;
1253 			pp->lencode = 0;
1254 			refclock_report(peer, CEVNT_FAULT);
1255 			return;
1256 		}
1257 	}
1258 	up->status = status;
1259 
1260 	if (peer->MODE == 0) { /* compatiblity to original version */
1261 		int bst = flags;
1262 
1263 		pp->day += moff[month - 1];
1264 
1265 		if(isleap_4(pp->year) && month > 2) { pp->day++; }/* Y2KFixes */
1266 
1267 		/* Convert to UTC if required */
1268 		if(bst & 2) {
1269 			pp->hour--;
1270 			if (pp->hour < 0) {
1271 				pp->hour = 23;
1272 				pp->day--;
1273 				/* If we try to wrap round the year
1274 				 * (BST on 1st Jan), reject.*/
1275 				if(pp->day < 0) {
1276 					pp->lencode = 0;
1277 					refclock_report(peer, CEVNT_BADTIME);
1278 					return;
1279 				}
1280 			}
1281 		}
1282 	}
1283 
1284 	if(peer->MODE > 0) {
1285 		if(pp->sloppyclockflag & CLK_FLAG1) {
1286 			struct tm  local;
1287 			struct tm *gmtp;
1288 			time_t	   unixtime;
1289 
1290 			/*
1291 			 * Convert to GMT for sites that distribute localtime.
1292 			 * This means we have to do Y2K conversion on the
1293 			 * 2-digit year; otherwise, we get the time wrong.
1294 			 */
1295 
1296 			memset(&local, 0, sizeof(local));
1297 
1298 			local.tm_year  = pp->year-1900;
1299 			local.tm_mon   = month-1;
1300 			local.tm_mday  = pp->day;
1301 			local.tm_hour  = pp->hour;
1302 			local.tm_min   = pp->minute;
1303 			local.tm_sec   = pp->second;
1304 			switch (peer->MODE) {
1305 			    case 1:
1306 				local.tm_isdst = (flags & 2);
1307 				break;
1308 			    case 2:
1309 				local.tm_isdst = (flags & 2);
1310 				break;
1311 			    case 3:
1312 				switch (flags & 3) {
1313 				    case 0: /* It is unclear exactly when the
1314 					       Arcron changes from DST->ST and
1315 					       ST->DST. Testing has shown this
1316 					       to be irregular. For the time
1317 					       being, let the OS decide. */
1318 					local.tm_isdst = 0;
1319 #ifdef DEBUG
1320 					if (debug)
1321 					    printf ("arc: DST = 00 (0)\n");
1322 #endif
1323 					break;
1324 				    case 1: /* dst->st time */
1325 					local.tm_isdst = -1;
1326 #ifdef DEBUG
1327 					if (debug)
1328 					    printf ("arc: DST = 01 (1)\n");
1329 #endif
1330 					break;
1331 				    case 2: /* st->dst time */
1332 					local.tm_isdst = -1;
1333 #ifdef DEBUG
1334 					if (debug)
1335 					    printf ("arc: DST = 10 (2)\n");
1336 #endif
1337 					break;
1338 				    case 3: /* dst time */
1339 				        local.tm_isdst = 1;
1340 #ifdef DEBUG
1341 					if (debug)
1342 					    printf ("arc: DST = 11 (3)\n");
1343 #endif
1344 					break;
1345 				}
1346 				break;
1347 			    default:
1348 				msyslog(LOG_NOTICE, "ARCRON: Invalid mode %d",
1349 					peer->MODE);
1350 				return;
1351 				break;
1352 			}
1353 			unixtime = mktime (&local);
1354 			if ((gmtp = gmtime (&unixtime)) == NULL)
1355 			{
1356 				pp->lencode = 0;
1357 				refclock_report (peer, CEVNT_FAULT);
1358 				return;
1359 			}
1360 			pp->year = gmtp->tm_year+1900;
1361 			month = gmtp->tm_mon+1;
1362 			pp->day = ymd2yd(pp->year,month,gmtp->tm_mday);
1363 			/* pp->day = gmtp->tm_yday; */
1364 			pp->hour = gmtp->tm_hour;
1365 			pp->minute = gmtp->tm_min;
1366 			pp->second = gmtp->tm_sec;
1367 #ifdef DEBUG
1368 			if (debug)
1369 			{
1370 				printf ("arc: time is %04d/%02d/%02d %02d:%02d:%02d UTC\n",
1371 					pp->year,month,gmtp->tm_mday,pp->hour,pp->minute,
1372 					pp->second);
1373 			}
1374 #endif
1375 		} else
1376 		{
1377 			/*
1378 			* For more rational sites distributing UTC
1379 			*/
1380 			pp->day    = ymd2yd(pp->year,month,pp->day);
1381 		}
1382 	}
1383 
1384 	if (peer->MODE == 0) { /* compatiblity to original version */
1385 				/* If clock signal quality is
1386 				 * unknown, revert to default PRECISION...*/
1387 		if(up->quality == QUALITY_UNKNOWN) {
1388 			peer->precision = PRECISION;
1389 		} else { /* ...else improve precision if flag3 is set... */
1390 			peer->precision = ((pp->sloppyclockflag & CLK_FLAG3) ?
1391 					   HIGHPRECISION : PRECISION);
1392 		}
1393 	} else {
1394 		if ((status == 0x3) && (pp->sloppyclockflag & CLK_FLAG2)) {
1395 			peer->precision = ((pp->sloppyclockflag & CLK_FLAG3) ?
1396 					   HIGHPRECISION : PRECISION);
1397 		} else if (up->quality == QUALITY_UNKNOWN) {
1398 			peer->precision = PRECISION;
1399 		} else {
1400 			peer->precision = ((pp->sloppyclockflag & CLK_FLAG3) ?
1401 					   HIGHPRECISION : PRECISION);
1402 		}
1403 	}
1404 
1405 	/* Notice and log any change (eg from initial defaults) for flags. */
1406 	if(up->saved_flags != pp->sloppyclockflag) {
1407 #ifdef DEBUG
1408 		msyslog(LOG_NOTICE, "ARCRON: flags enabled: %s%s%s%s",
1409 			((pp->sloppyclockflag & CLK_FLAG1) ? "1" : "."),
1410 			((pp->sloppyclockflag & CLK_FLAG2) ? "2" : "."),
1411 			((pp->sloppyclockflag & CLK_FLAG3) ? "3" : "."),
1412 			((pp->sloppyclockflag & CLK_FLAG4) ? "4" : "."));
1413 		/* Note effects of flags changing... */
1414 		if(debug) {
1415 			printf("arc: PRECISION = %d.\n", peer->precision);
1416 		}
1417 #endif
1418 		up->saved_flags = pp->sloppyclockflag;
1419 	}
1420 
1421 	/* Note time of last believable timestamp. */
1422 	pp->lastrec = up->lastrec;
1423 
1424 #ifdef ARCRON_LEAPSECOND_KEEN
1425 	/* Find out if a leap-second might just have happened...
1426 	   (ie is this the first hour of the first day of Jan or Jul?)
1427 	*/
1428 	if((pp->hour == 0) &&
1429 	   (pp->day == 1) &&
1430 	   ((month == 1) || (month == 7))) {
1431 		if(possible_leap >= 0) {
1432 			/* A leap may have happened, and no resync has started yet...*/
1433 			possible_leap = 1;
1434 		}
1435 	} else {
1436 		/* Definitely not leap-second territory... */
1437 		possible_leap = 0;
1438 	}
1439 #endif
1440 
1441 	if (!refclock_process(pp)) {
1442 		pp->lencode = 0;
1443 		refclock_report(peer, CEVNT_BADTIME);
1444 		return;
1445 	}
1446 	record_clock_stats(&peer->srcadr, pp->a_lastcode);
1447 	refclock_receive(peer);
1448 }
1449 
1450 
1451 /* request_time() sends a time request to the clock with given peer. */
1452 /* This automatically reports a fault if necessary. */
1453 /* No data should be sent after this until arc_poll() returns. */
1454 static  void    request_time    (int, struct peer *);
1455 static void
1456 request_time(
1457 	int unit,
1458 	struct peer *peer
1459 	)
1460 {
1461 	struct refclockproc *pp = peer->procptr;
1462 	register struct arcunit *up = pp->unitptr;
1463 #ifdef DEBUG
1464 	if(debug) { printf("arc: unit %d: requesting time.\n", unit); }
1465 #endif
1466 	if (!send_slow(up, pp->io.fd, "o\r")) {
1467 #ifdef DEBUG
1468 		if (debug) {
1469 			printf("arc: unit %d: problem sending", unit);
1470 		}
1471 #endif
1472 		pp->lencode = 0;
1473 		refclock_report(peer, CEVNT_FAULT);
1474 		return;
1475 	}
1476 	pp->polls++;
1477 }
1478 
1479 /*
1480  * arc_poll - called by the transmit procedure
1481  */
1482 static void
1483 arc_poll(
1484 	int unit,
1485 	struct peer *peer
1486 	)
1487 {
1488 	register struct arcunit *up;
1489 	struct refclockproc *pp;
1490 	int resync_needed;              /* Should we start a resync? */
1491 
1492 	pp = peer->procptr;
1493 	up = pp->unitptr;
1494 #if 0
1495 	pp->lencode = 0;
1496 	memset(pp->a_lastcode, 0, sizeof(pp->a_lastcode));
1497 #endif
1498 
1499 #if 0
1500 	/* Flush input. */
1501 	tcflush(pp->io.fd, TCIFLUSH);
1502 #endif
1503 
1504 	/* Resync if our next scheduled resync time is here or has passed. */
1505 	resync_needed = ( !(pp->sloppyclockflag & CLK_FLAG2) &&
1506 			  (up->next_resync <= current_time) );
1507 
1508 #ifdef ARCRON_LEAPSECOND_KEEN
1509 	/*
1510 	  Try to catch a potential leap-second insertion or deletion quickly.
1511 
1512 	  In addition to the normal NTP fun of clocks that don't report
1513 	  leap-seconds spooking their hosts, this clock does not even
1514 	  sample the radio sugnal the whole time, so may miss a
1515 	  leap-second insertion or deletion for up to a whole sample
1516 	  time.
1517 
1518 	  To try to minimise this effect, if in the first few minutes of
1519 	  the day immediately following a leap-second-insertion point
1520 	  (ie in the first hour of the first day of the first and sixth
1521 	  months), and if the last resync was in the previous day, and a
1522 	  resync is not already in progress, resync the clock
1523 	  immediately.
1524 
1525 	*/
1526 	if((possible_leap > 0) &&       /* Must be 00:XX 01/0{1,7}/XXXX. */
1527 	   (!up->resyncing)) {          /* No resync in progress yet. */
1528 		resync_needed = 1;
1529 		possible_leap = -1;          /* Prevent multiple resyncs. */
1530 		msyslog(LOG_NOTICE,"ARCRON: unit %d: checking for leap second",unit);
1531 	}
1532 #endif
1533 
1534 	/* Do a resync if required... */
1535 	if(resync_needed) {
1536 		/* First, reset quality value to `unknown' so we can detect */
1537 		/* when a quality message has been responded to by this     */
1538 		/* being set to some other value.                           */
1539 		up->quality = QUALITY_UNKNOWN;
1540 
1541 		/* Note that we are resyncing... */
1542 		up->resyncing = 1;
1543 
1544 		/* Now actually send the resync command and an immediate poll. */
1545 #ifdef DEBUG
1546 		if(debug) { printf("arc: sending resync command (h\\r).\n"); }
1547 #endif
1548 		msyslog(LOG_NOTICE, "ARCRON: unit %d: sending resync command", unit);
1549 		send_slow(up, pp->io.fd, "h\r");
1550 
1551 		/* Schedule our next resync... */
1552 		up->next_resync = current_time + DEFAULT_RESYNC_TIME;
1553 
1554 		/* Drop through to request time if appropriate. */
1555 	}
1556 
1557 	/* If clock quality is too poor to trust, indicate a fault. */
1558 	/* If quality is QUALITY_UNKNOWN and ARCRON_KEEN is defined,*/
1559 	/* we'll cross our fingers and just hope that the thing     */
1560 	/* synced so quickly we did not catch it---we'll            */
1561 	/* double-check the clock is OK elsewhere.                  */
1562 	if(
1563 #ifdef ARCRON_KEEN
1564 		(up->quality != QUALITY_UNKNOWN) &&
1565 #else
1566 		(up->quality == QUALITY_UNKNOWN) ||
1567 #endif
1568 		(up->quality < MIN_CLOCK_QUALITY_OK)) {
1569 #ifdef DEBUG
1570 		if(debug) {
1571 			printf("arc: clock quality %d too poor.\n", up->quality);
1572 		}
1573 #endif
1574 		pp->lencode = 0;
1575 		refclock_report(peer, CEVNT_FAULT);
1576 		return;
1577 	}
1578 	/* This is the normal case: request a timestamp. */
1579 	request_time(unit, peer);
1580 }
1581 
1582 #else
1583 int refclock_arc_bs;
1584 #endif
1585