xref: /freebsd/contrib/ntp/parseutil/dcfd.c (revision 38f0b757fd84d17d0fc24739a7cda160c4516d81)
1 /*
2  * /src/NTP/REPOSITORY/ntp4-dev/parseutil/dcfd.c,v 4.18 2005/10/07 22:08:18 kardel RELEASE_20051008_A
3  *
4  * dcfd.c,v 4.18 2005/10/07 22:08:18 kardel RELEASE_20051008_A
5  *
6  * DCF77 100/200ms pulse synchronisation daemon program (via 50Baud serial line)
7  *
8  * Features:
9  *  DCF77 decoding
10  *  simple NTP loopfilter logic for local clock
11  *  interactive display for debugging
12  *
13  * Lacks:
14  *  Leap second handling (at that level you should switch to NTP Version 4 - really!)
15  *
16  * Copyright (c) 1995-2005 by Frank Kardel <kardel <AT> ntp.org>
17  * Copyright (c) 1989-1994 by Frank Kardel, Friedrich-Alexander Universit�t Erlangen-N�rnberg, Germany
18  *
19  * Redistribution and use in source and binary forms, with or without
20  * modification, are permitted provided that the following conditions
21  * are met:
22  * 1. Redistributions of source code must retain the above copyright
23  *    notice, this list of conditions and the following disclaimer.
24  * 2. Redistributions in binary form must reproduce the above copyright
25  *    notice, this list of conditions and the following disclaimer in the
26  *    documentation and/or other materials provided with the distribution.
27  * 3. Neither the name of the author nor the names of its contributors
28  *    may be used to endorse or promote products derived from this software
29  *    without specific prior written permission.
30  *
31  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
32  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
33  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
34  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
35  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
39  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
40  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
41  * SUCH DAMAGE.
42  *
43  */
44 
45 #ifdef HAVE_CONFIG_H
46 # include <config.h>
47 #endif
48 
49 #include <sys/ioctl.h>
50 #include <unistd.h>
51 #include <stdio.h>
52 #include <fcntl.h>
53 #include <sys/types.h>
54 #include <sys/time.h>
55 #include <signal.h>
56 #include <syslog.h>
57 #include <time.h>
58 
59 /*
60  * NTP compilation environment
61  */
62 #include "ntp_stdlib.h"
63 #include "ntpd.h"   /* indirectly include ntp.h to get YEAR_PIVOT   Y2KFixes */
64 
65 /*
66  * select which terminal handling to use (currently only SysV variants)
67  */
68 #if defined(HAVE_TERMIOS_H) || defined(STREAM)
69 #include <termios.h>
70 #define TTY_GETATTR(_FD_, _ARG_) tcgetattr((_FD_), (_ARG_))
71 #define TTY_SETATTR(_FD_, _ARG_) tcsetattr((_FD_), TCSANOW, (_ARG_))
72 #else  /* not HAVE_TERMIOS_H || STREAM */
73 # if defined(HAVE_TERMIO_H) || defined(HAVE_SYSV_TTYS)
74 #  include <termio.h>
75 #  define TTY_GETATTR(_FD_, _ARG_) ioctl((_FD_), TCGETA, (_ARG_))
76 #  define TTY_SETATTR(_FD_, _ARG_) ioctl((_FD_), TCSETAW, (_ARG_))
77 # endif/* HAVE_TERMIO_H || HAVE_SYSV_TTYS */
78 #endif /* not HAVE_TERMIOS_H || STREAM */
79 
80 
81 #ifndef TTY_GETATTR
82 #include "Bletch: MUST DEFINE ONE OF 'HAVE_TERMIOS_H' or 'HAVE_TERMIO_H'"
83 #endif
84 
85 #ifndef days_per_year
86 #define days_per_year(_x_) (((_x_) % 4) ? 365 : (((_x_) % 400) ? 365 : 366))
87 #endif
88 
89 #define timernormalize(_a_) \
90 	if ((_a_)->tv_usec >= 1000000) \
91 	{ \
92 		(_a_)->tv_sec  += (_a_)->tv_usec / 1000000; \
93 		(_a_)->tv_usec  = (_a_)->tv_usec % 1000000; \
94 	} \
95 	if ((_a_)->tv_usec < 0) \
96 	{ \
97 		(_a_)->tv_sec  -= 1 + (-(_a_)->tv_usec / 1000000); \
98 		(_a_)->tv_usec = 999999 - (-(_a_)->tv_usec - 1); \
99 	}
100 
101 #ifdef timeradd
102 #undef timeradd
103 #endif
104 #define timeradd(_a_, _b_) \
105 	(_a_)->tv_sec  += (_b_)->tv_sec; \
106 	(_a_)->tv_usec += (_b_)->tv_usec; \
107 	timernormalize((_a_))
108 
109 #ifdef timersub
110 #undef timersub
111 #endif
112 #define timersub(_a_, _b_) \
113 	(_a_)->tv_sec  -= (_b_)->tv_sec; \
114 	(_a_)->tv_usec -= (_b_)->tv_usec; \
115 	timernormalize((_a_))
116 
117 /*
118  * debug macros
119  */
120 #define PRINTF if (interactive) printf
121 #define LPRINTF if (interactive && loop_filter_debug) printf
122 
123 #ifdef DEBUG
124 #define dprintf(_x_) LPRINTF _x_
125 #else
126 #define dprintf(_x_)
127 #endif
128 
129 #ifdef DECL_ERRNO
130      extern int errno;
131 #endif
132 
133 static char *revision = "4.18";
134 
135 /*
136  * display received data (avoids also detaching from tty)
137  */
138 static int interactive = 0;
139 
140 /*
141  * display loopfilter (clock control) variables
142  */
143 static int loop_filter_debug = 0;
144 
145 /*
146  * do not set/adjust system time
147  */
148 static int no_set = 0;
149 
150 /*
151  * time that passes between start of DCF impulse and time stamping (fine
152  * adjustment) in microseconds (receiver/OS dependent)
153  */
154 #define DEFAULT_DELAY	230000	/* rough estimate */
155 
156 /*
157  * The two states we can be in - eithe we receive nothing
158  * usable or we have the correct time
159  */
160 #define NO_SYNC		0x01
161 #define SYNC		0x02
162 
163 static int    sync_state = NO_SYNC;
164 static time_t last_sync;
165 
166 static unsigned long ticks = 0;
167 
168 static char pat[] = "-\\|/";
169 
170 #define LINES		(24-2)	/* error lines after which the two headlines are repeated */
171 
172 #define MAX_UNSYNC	(10*60)	/* allow synchronisation loss for 10 minutes */
173 #define NOTICE_INTERVAL (20*60)	/* mention missing synchronisation every 20 minutes */
174 
175 /*
176  * clock adjustment PLL - see NTP protocol spec (RFC1305) for details
177  */
178 
179 #define USECSCALE	10
180 #define TIMECONSTANT	2
181 #define ADJINTERVAL	0
182 #define FREQ_WEIGHT	18
183 #define PHASE_WEIGHT	7
184 #define MAX_DRIFT	0x3FFFFFFF
185 
186 #define R_SHIFT(_X_, _Y_) (((_X_) < 0) ? -(-(_X_) >> (_Y_)) : ((_X_) >> (_Y_)))
187 
188 static struct timeval max_adj_offset = { 0, 128000 };
189 
190 static long clock_adjust = 0;	/* current adjustment value (usec * 2^USECSCALE) */
191 static long accum_drift   = 0;	/* accumulated drift value  (usec / ADJINTERVAL) */
192 static long adjustments  = 0;
193 static char skip_adjust  = 1;	/* discard first adjustment (bad samples) */
194 
195 /*
196  * DCF77 state flags
197  */
198 #define DCFB_ANNOUNCE           0x0001 /* switch time zone warning (DST switch) */
199 #define DCFB_DST                0x0002 /* DST in effect */
200 #define DCFB_LEAP		0x0004 /* LEAP warning (1 hour prior to occurrence) */
201 #define DCFB_ALTERNATE		0x0008 /* alternate antenna used */
202 
203 struct clocktime		/* clock time broken up from time code */
204 {
205 	long wday;		/* Day of week: 1: Monday - 7: Sunday */
206 	long day;
207 	long month;
208 	long year;
209 	long hour;
210 	long minute;
211 	long second;
212 	long usecond;
213 	long utcoffset;	/* in minutes */
214 	long flags;		/* current clock status  (DCF77 state flags) */
215 };
216 
217 typedef struct clocktime clocktime_t;
218 
219 /*
220  * (usually) quick constant multiplications
221  */
222 #define TIMES10(_X_) (((_X_) << 3) + ((_X_) << 1))	/* *8 + *2 */
223 #define TIMES24(_X_) (((_X_) << 4) + ((_X_) << 3))      /* *16 + *8 */
224 #define TIMES60(_X_) ((((_X_) << 4)  - (_X_)) << 2)     /* *(16 - 1) *4 */
225 /*
226  * generic l_abs() function
227  */
228 #define l_abs(_x_)     (((_x_) < 0) ? -(_x_) : (_x_))
229 
230 /*
231  * conversion related return/error codes
232  */
233 #define CVT_MASK	0x0000000F /* conversion exit code */
234 #define   CVT_NONE	0x00000001 /* format not applicable */
235 #define   CVT_FAIL	0x00000002 /* conversion failed - error code returned */
236 #define   CVT_OK	0x00000004 /* conversion succeeded */
237 #define CVT_BADFMT	0x00000010 /* general format error - (unparsable) */
238 #define CVT_BADDATE	0x00000020 /* invalid date */
239 #define CVT_BADTIME	0x00000040 /* invalid time */
240 
241 /*
242  * DCF77 raw time code
243  *
244  * From "Zur Zeit", Physikalisch-Technische Bundesanstalt (PTB), Braunschweig
245  * und Berlin, Maerz 1989
246  *
247  * Timecode transmission:
248  * AM:
249  *	time marks are send every second except for the second before the
250  *	next minute mark
251  *	time marks consist of a reduction of transmitter power to 25%
252  *	of the nominal level
253  *	the falling edge is the time indication (on time)
254  *	time marks of a 100ms duration constitute a logical 0
255  *	time marks of a 200ms duration constitute a logical 1
256  * FM:
257  *	see the spec. (basically a (non-)inverted psuedo random phase shift)
258  *
259  * Encoding:
260  * Second	Contents
261  * 0  - 10	AM: free, FM: 0
262  * 11 - 14	free
263  * 15		R     - alternate antenna
264  * 16		A1    - expect zone change (1 hour before)
265  * 17 - 18	Z1,Z2 - time zone
266  *		 0  0 illegal
267  *		 0  1 MEZ  (MET)
268  *		 1  0 MESZ (MED, MET DST)
269  *		 1  1 illegal
270  * 19		A2    - expect leap insertion/deletion (1 hour before)
271  * 20		S     - start of time code (1)
272  * 21 - 24	M1    - BCD (lsb first) Minutes
273  * 25 - 27	M10   - BCD (lsb first) 10 Minutes
274  * 28		P1    - Minute Parity (even)
275  * 29 - 32	H1    - BCD (lsb first) Hours
276  * 33 - 34      H10   - BCD (lsb first) 10 Hours
277  * 35		P2    - Hour Parity (even)
278  * 36 - 39	D1    - BCD (lsb first) Days
279  * 40 - 41	D10   - BCD (lsb first) 10 Days
280  * 42 - 44	DW    - BCD (lsb first) day of week (1: Monday -> 7: Sunday)
281  * 45 - 49	MO    - BCD (lsb first) Month
282  * 50           MO0   - 10 Months
283  * 51 - 53	Y1    - BCD (lsb first) Years
284  * 54 - 57	Y10   - BCD (lsb first) 10 Years
285  * 58 		P3    - Date Parity (even)
286  * 59		      - usually missing (minute indication), except for leap insertion
287  */
288 
289 /*-----------------------------------------------------------------------
290  * conversion table to map DCF77 bit stream into data fields.
291  * Encoding:
292  *   Each field of the DCF77 code is described with two adjacent entries in
293  *   this table. The first entry specifies the offset into the DCF77 data stream
294  *   while the length is given as the difference between the start index and
295  *   the start index of the following field.
296  */
297 static struct rawdcfcode
298 {
299 	char offset;			/* start bit */
300 } rawdcfcode[] =
301 {
302 	{  0 }, { 15 }, { 16 }, { 17 }, { 19 }, { 20 }, { 21 }, { 25 }, { 28 }, { 29 },
303 	{ 33 }, { 35 }, { 36 }, { 40 }, { 42 }, { 45 }, { 49 }, { 50 }, { 54 }, { 58 }, { 59 }
304 };
305 
306 /*-----------------------------------------------------------------------
307  * symbolic names for the fields of DCF77 describes in "rawdcfcode".
308  * see comment above for the structure of the DCF77 data
309  */
310 #define DCF_M	0
311 #define DCF_R	1
312 #define DCF_A1	2
313 #define DCF_Z	3
314 #define DCF_A2	4
315 #define DCF_S	5
316 #define DCF_M1	6
317 #define DCF_M10	7
318 #define DCF_P1	8
319 #define DCF_H1	9
320 #define DCF_H10	10
321 #define DCF_P2	11
322 #define DCF_D1	12
323 #define DCF_D10	13
324 #define DCF_DW	14
325 #define DCF_MO	15
326 #define DCF_MO0	16
327 #define DCF_Y1	17
328 #define DCF_Y10	18
329 #define DCF_P3	19
330 
331 /*-----------------------------------------------------------------------
332  * parity field table (same encoding as rawdcfcode)
333  * This table describes the sections of the DCF77 code that are
334  * parity protected
335  */
336 static struct partab
337 {
338 	char offset;			/* start bit of parity field */
339 } partab[] =
340 {
341 	{ 21 }, { 29 }, { 36 }, { 59 }
342 };
343 
344 /*-----------------------------------------------------------------------
345  * offsets for parity field descriptions
346  */
347 #define DCF_P_P1	0
348 #define DCF_P_P2	1
349 #define DCF_P_P3	2
350 
351 /*-----------------------------------------------------------------------
352  * legal values for time zone information
353  */
354 #define DCF_Z_MET 0x2
355 #define DCF_Z_MED 0x1
356 
357 /*-----------------------------------------------------------------------
358  * symbolic representation if the DCF77 data stream
359  */
360 static struct dcfparam
361 {
362 	unsigned char onebits[60];
363 	unsigned char zerobits[60];
364 } dcfparam =
365 {
366 	"###############RADMLS1248124P124812P1248121241248112481248P", /* 'ONE' representation */
367 	"--------------------s-------p------p----------------------p"  /* 'ZERO' representation */
368 };
369 
370 /*-----------------------------------------------------------------------
371  * extract a bitfield from DCF77 datastream
372  * All numeric fields are LSB first.
373  * buf holds a pointer to a DCF77 data buffer in symbolic
374  *     representation
375  * idx holds the index to the field description in rawdcfcode
376  */
377 static unsigned long
378 ext_bf(
379 	register unsigned char *buf,
380 	register int   idx
381 	)
382 {
383 	register unsigned long sum = 0;
384 	register int i, first;
385 
386 	first = rawdcfcode[idx].offset;
387 
388 	for (i = rawdcfcode[idx+1].offset - 1; i >= first; i--)
389 	{
390 		sum <<= 1;
391 		sum |= (buf[i] != dcfparam.zerobits[i]);
392 	}
393 	return sum;
394 }
395 
396 /*-----------------------------------------------------------------------
397  * check even parity integrity for a bitfield
398  *
399  * buf holds a pointer to a DCF77 data buffer in symbolic
400  *     representation
401  * idx holds the index to the field description in partab
402  */
403 static unsigned
404 pcheck(
405 	register unsigned char *buf,
406 	register int   idx
407 	)
408 {
409 	register int i,last;
410 	register unsigned psum = 1;
411 
412 	last = partab[idx+1].offset;
413 
414 	for (i = partab[idx].offset; i < last; i++)
415 	    psum ^= (buf[i] != dcfparam.zerobits[i]);
416 
417 	return psum;
418 }
419 
420 /*-----------------------------------------------------------------------
421  * convert a DCF77 data buffer into wall clock time + flags
422  *
423  * buffer holds a pointer to a DCF77 data buffer in symbolic
424  *        representation
425  * size   describes the length of DCF77 information in bits (represented
426  *        as chars in symbolic notation
427  * clock  points to a wall clock time description of the DCF77 data (result)
428  */
429 static unsigned long
430 convert_rawdcf(
431 	       unsigned char   *buffer,
432 	       int              size,
433 	       clocktime_t     *clock_time
434 	       )
435 {
436 	if (size < 57)
437 	{
438 		PRINTF("%-30s", "*** INCOMPLETE");
439 		return CVT_NONE;
440 	}
441 
442 	/*
443 	 * check Start and Parity bits
444 	 */
445 	if ((ext_bf(buffer, DCF_S) == 1) &&
446 	    pcheck(buffer, DCF_P_P1) &&
447 	    pcheck(buffer, DCF_P_P2) &&
448 	    pcheck(buffer, DCF_P_P3))
449 	{
450 		/*
451 		 * buffer OK - extract all fields and build wall clock time from them
452 		 */
453 
454 		clock_time->flags  = 0;
455 		clock_time->usecond= 0;
456 		clock_time->second = 0;
457 		clock_time->minute = ext_bf(buffer, DCF_M10);
458 		clock_time->minute = TIMES10(clock_time->minute) + ext_bf(buffer, DCF_M1);
459 		clock_time->hour   = ext_bf(buffer, DCF_H10);
460 		clock_time->hour   = TIMES10(clock_time->hour)   + ext_bf(buffer, DCF_H1);
461 		clock_time->day    = ext_bf(buffer, DCF_D10);
462 		clock_time->day    = TIMES10(clock_time->day)    + ext_bf(buffer, DCF_D1);
463 		clock_time->month  = ext_bf(buffer, DCF_MO0);
464 		clock_time->month  = TIMES10(clock_time->month)  + ext_bf(buffer, DCF_MO);
465 		clock_time->year   = ext_bf(buffer, DCF_Y10);
466 		clock_time->year   = TIMES10(clock_time->year)   + ext_bf(buffer, DCF_Y1);
467 		clock_time->wday   = ext_bf(buffer, DCF_DW);
468 
469 		/*
470 		 * determine offset to UTC by examining the time zone
471 		 */
472 		switch (ext_bf(buffer, DCF_Z))
473 		{
474 		    case DCF_Z_MET:
475 			clock_time->utcoffset = -60;
476 			break;
477 
478 		    case DCF_Z_MED:
479 			clock_time->flags     |= DCFB_DST;
480 			clock_time->utcoffset  = -120;
481 			break;
482 
483 		    default:
484 			PRINTF("%-30s", "*** BAD TIME ZONE");
485 			return CVT_FAIL|CVT_BADFMT;
486 		}
487 
488 		/*
489 		 * extract various warnings from DCF77
490 		 */
491 		if (ext_bf(buffer, DCF_A1))
492 		    clock_time->flags |= DCFB_ANNOUNCE;
493 
494 		if (ext_bf(buffer, DCF_A2))
495 		    clock_time->flags |= DCFB_LEAP;
496 
497 		if (ext_bf(buffer, DCF_R))
498 		    clock_time->flags |= DCFB_ALTERNATE;
499 
500 		return CVT_OK;
501 	}
502 	else
503 	{
504 		/*
505 		 * bad format - not for us
506 		 */
507 		PRINTF("%-30s", "*** BAD FORMAT (invalid/parity)");
508 		return CVT_FAIL|CVT_BADFMT;
509 	}
510 }
511 
512 /*-----------------------------------------------------------------------
513  * raw dcf input routine - fix up 50 baud
514  * characters for 1/0 decision
515  */
516 static unsigned long
517 cvt_rawdcf(
518 	   unsigned char   *buffer,
519 	   int              size,
520 	   clocktime_t     *clock_time
521 	   )
522 {
523 	register unsigned char *s = buffer;
524 	register unsigned char *e = buffer + size;
525 	register unsigned char *b = dcfparam.onebits;
526 	register unsigned char *c = dcfparam.zerobits;
527 	register unsigned rtc = CVT_NONE;
528 	register unsigned int i, lowmax, highmax, cutoff, span;
529 #define BITS 9
530 	unsigned char     histbuf[BITS];
531 	/*
532 	 * the input buffer contains characters with runs of consecutive
533 	 * bits set. These set bits are an indication of the DCF77 pulse
534 	 * length. We assume that we receive the pulse at 50 Baud. Thus
535 	 * a 100ms pulse would generate a 4 bit train (20ms per bit and
536 	 * start bit)
537 	 * a 200ms pulse would create all zeroes (and probably a frame error)
538 	 *
539 	 * The basic idea is that on corret reception we must have two
540 	 * maxima in the pulse length distribution histogram. (one for
541 	 * the zero representing pulses and one for the one representing
542 	 * pulses)
543 	 * There will always be ones in the datastream, thus we have to see
544 	 * two maxima.
545 	 * The best point to cut for a 1/0 decision is the minimum between those
546 	 * between the maxima. The following code tries to find this cutoff point.
547 	 */
548 
549 	/*
550 	 * clear histogram buffer
551 	 */
552 	for (i = 0; i < BITS; i++)
553 	{
554 		histbuf[i] = 0;
555 	}
556 
557 	cutoff = 0;
558 	lowmax = 0;
559 
560 	/*
561 	 * convert sequences of set bits into bits counts updating
562 	 * the histogram alongway
563 	 */
564 	while (s < e)
565 	{
566 		register unsigned int ch = *s ^ 0xFF;
567 		/*
568 		 * check integrity and update histogramm
569 		 */
570 		if (!((ch+1) & ch) || !*s)
571 		{
572 			/*
573 			 * character ok
574 			 */
575 			for (i = 0; ch; i++)
576 			{
577 				ch >>= 1;
578 			}
579 
580 			*s = i;
581 			histbuf[i]++;
582 			cutoff += i;
583 			lowmax++;
584 		}
585 		else
586 		{
587 			/*
588 			 * invalid character (no consecutive bit sequence)
589 			 */
590 			dprintf(("parse: cvt_rawdcf: character check for 0x%x@%d FAILED\n", *s, s - buffer));
591 			*s = (unsigned char)~0;
592 			rtc = CVT_FAIL|CVT_BADFMT;
593 		}
594 		s++;
595 	}
596 
597 	/*
598 	 * first cutoff estimate (average bit count - must be between both
599 	 * maxima)
600 	 */
601 	if (lowmax)
602 	{
603 		cutoff /= lowmax;
604 	}
605 	else
606 	{
607 		cutoff = 4;	/* doesn't really matter - it'll fail anyway, but gives error output */
608 	}
609 
610 	dprintf(("parse: cvt_rawdcf: average bit count: %d\n", cutoff));
611 
612 	lowmax = 0;  /* weighted sum */
613 	highmax = 0; /* bitcount */
614 
615 	/*
616 	 * collect weighted sum of lower bits (left of initial guess)
617 	 */
618 	dprintf(("parse: cvt_rawdcf: histogram:"));
619 	for (i = 0; i <= cutoff; i++)
620 	{
621 		lowmax  += histbuf[i] * i;
622 		highmax += histbuf[i];
623 		dprintf((" %d", histbuf[i]));
624 	}
625 	dprintf((" <M>"));
626 
627 	/*
628 	 * round up
629 	 */
630 	lowmax += highmax / 2;
631 
632 	/*
633 	 * calculate lower bit maximum (weighted sum / bit count)
634 	 *
635 	 * avoid divide by zero
636 	 */
637 	if (highmax)
638 	{
639 		lowmax /= highmax;
640 	}
641 	else
642 	{
643 		lowmax = 0;
644 	}
645 
646 	highmax = 0; /* weighted sum of upper bits counts */
647 	cutoff = 0;  /* bitcount */
648 
649 	/*
650 	 * collect weighted sum of lower bits (right of initial guess)
651 	 */
652 	for (; i < BITS; i++)
653 	{
654 		highmax+=histbuf[i] * i;
655 		cutoff +=histbuf[i];
656 		dprintf((" %d", histbuf[i]));
657 	}
658 	dprintf(("\n"));
659 
660 	/*
661 	 * determine upper maximum (weighted sum / bit count)
662 	 */
663 	if (cutoff)
664 	{
665 		highmax /= cutoff;
666 	}
667 	else
668 	{
669 		highmax = BITS-1;
670 	}
671 
672 	/*
673 	 * following now holds:
674 	 * lowmax <= cutoff(initial guess) <= highmax
675 	 * best cutoff is the minimum nearest to higher bits
676 	 */
677 
678 	/*
679 	 * find the minimum between lowmax and highmax (detecting
680 	 * possibly a minimum span)
681 	 */
682 	span = cutoff = lowmax;
683 	for (i = lowmax; i <= highmax; i++)
684 	{
685 		if (histbuf[cutoff] > histbuf[i])
686 		{
687 			/*
688 			 * got a new minimum move beginning of minimum (cutoff) and
689 			 * end of minimum (span) there
690 			 */
691 			cutoff = span = i;
692 		}
693 		else
694 		    if (histbuf[cutoff] == histbuf[i])
695 		    {
696 			    /*
697 			     * minimum not better yet - but it spans more than
698 			     * one bit value - follow it
699 			     */
700 			    span = i;
701 		    }
702 	}
703 
704 	/*
705 	 * cutoff point for 1/0 decision is the middle of the minimum section
706 	 * in the histogram
707 	 */
708 	cutoff = (cutoff + span) / 2;
709 
710 	dprintf(("parse: cvt_rawdcf: lower maximum %d, higher maximum %d, cutoff %d\n", lowmax, highmax, cutoff));
711 
712 	/*
713 	 * convert the bit counts to symbolic 1/0 information for data conversion
714 	 */
715 	s = buffer;
716 	while ((s < e) && *c && *b)
717 	{
718 		if (*s == (unsigned char)~0)
719 		{
720 			/*
721 			 * invalid character
722 			 */
723 			*s = '?';
724 		}
725 		else
726 		{
727 			/*
728 			 * symbolic 1/0 representation
729 			 */
730 			*s = (*s >= cutoff) ? *b : *c;
731 		}
732 		s++;
733 		b++;
734 		c++;
735 	}
736 
737 	/*
738 	 * if everything went well so far return the result of the symbolic
739 	 * conversion routine else just the accumulated errors
740 	 */
741 	if (rtc != CVT_NONE)
742 	{
743 		PRINTF("%-30s", "*** BAD DATA");
744 	}
745 
746 	return (rtc == CVT_NONE) ? convert_rawdcf(buffer, size, clock_time) : rtc;
747 }
748 
749 /*-----------------------------------------------------------------------
750  * convert a wall clock time description of DCF77 to a Unix time (seconds
751  * since 1.1. 1970 UTC)
752  */
753 static time_t
754 dcf_to_unixtime(
755 		clocktime_t   *clock_time,
756 		unsigned *cvtrtc
757 		)
758 {
759 #define SETRTC(_X_)	{ if (cvtrtc) *cvtrtc = (_X_); }
760 	static int days_of_month[] =
761 	{
762 		0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
763 	};
764 	register int i;
765 	time_t t;
766 
767 	/*
768 	 * map 2 digit years to 19xx (DCF77 is a 20th century item)
769 	 */
770 	if ( clock_time->year < YEAR_PIVOT ) 	/* in case of	   Y2KFixes [ */
771 		clock_time->year += 100;	/* *year%100, make tm_year */
772 						/* *(do we need this?) */
773 	if ( clock_time->year < YEAR_BREAK )	/* (failsafe if) */
774 	    clock_time->year += 1900;				/* Y2KFixes ] */
775 
776 	/*
777 	 * must have been a really bad year code - drop it
778 	 */
779 	if (clock_time->year < (YEAR_PIVOT + 1900) )		/* Y2KFixes */
780 	{
781 		SETRTC(CVT_FAIL|CVT_BADDATE);
782 		return -1;
783 	}
784 	/*
785 	 * sorry, slow section here - but it's not time critical anyway
786 	 */
787 
788 	/*
789 	 * calculate days since 1970 (watching leap years)
790 	 */
791 	t = julian0( clock_time->year ) - julian0( 1970 );
792 
793   				/* month */
794 	if (clock_time->month <= 0 || clock_time->month > 12)
795 	{
796 		SETRTC(CVT_FAIL|CVT_BADDATE);
797 		return -1;		/* bad month */
798 	}
799 				/* adjust current leap year */
800 #if 0
801 	if (clock_time->month < 3 && days_per_year(clock_time->year) == 366)
802 	    t--;
803 #endif
804 
805 	/*
806 	 * collect days from months excluding the current one
807 	 */
808 	for (i = 1; i < clock_time->month; i++)
809 	{
810 		t += days_of_month[i];
811 	}
812 				/* day */
813 	if (clock_time->day < 1 || ((clock_time->month == 2 && days_per_year(clock_time->year) == 366) ?
814 			       clock_time->day > 29 : clock_time->day > days_of_month[clock_time->month]))
815 	{
816 		SETRTC(CVT_FAIL|CVT_BADDATE);
817 		return -1;		/* bad day */
818 	}
819 
820 	/*
821 	 * collect days from date excluding the current one
822 	 */
823 	t += clock_time->day - 1;
824 
825 				/* hour */
826 	if (clock_time->hour < 0 || clock_time->hour >= 24)
827 	{
828 		SETRTC(CVT_FAIL|CVT_BADTIME);
829 		return -1;		/* bad hour */
830 	}
831 
832 	/*
833 	 * calculate hours from 1. 1. 1970
834 	 */
835 	t = TIMES24(t) + clock_time->hour;
836 
837   				/* min */
838 	if (clock_time->minute < 0 || clock_time->minute > 59)
839 	{
840 		SETRTC(CVT_FAIL|CVT_BADTIME);
841 		return -1;		/* bad min */
842 	}
843 
844 	/*
845 	 * calculate minutes from 1. 1. 1970
846 	 */
847 	t = TIMES60(t) + clock_time->minute;
848 				/* sec */
849 
850 	/*
851 	 * calculate UTC in minutes
852 	 */
853 	t += clock_time->utcoffset;
854 
855 	if (clock_time->second < 0 || clock_time->second > 60)	/* allow for LEAPs */
856 	{
857 		SETRTC(CVT_FAIL|CVT_BADTIME);
858 		return -1;		/* bad sec */
859 	}
860 
861 	/*
862 	 * calculate UTC in seconds - phew !
863 	 */
864 	t  = TIMES60(t) + clock_time->second;
865 				/* done */
866 	return t;
867 }
868 
869 /*-----------------------------------------------------------------------
870  * cheap half baked 1/0 decision - for interactive operation only
871  */
872 static char
873 type(
874      unsigned int c
875      )
876 {
877 	c ^= 0xFF;
878 	return (c > 0xF);
879 }
880 
881 /*-----------------------------------------------------------------------
882  * week day representation
883  */
884 static const char *wday[8] =
885 {
886 	"??",
887 	"Mo",
888 	"Tu",
889 	"We",
890 	"Th",
891 	"Fr",
892 	"Sa",
893 	"Su"
894 };
895 
896 /*-----------------------------------------------------------------------
897  * generate a string representation for a timeval
898  */
899 static char *
900 pr_timeval(
901 	   struct timeval *val
902 	   )
903 {
904 	static char buf[20];
905 
906 	if (val->tv_sec == 0)
907 	    sprintf(buf, "%c0.%06ld", (val->tv_usec < 0) ? '-' : '+', (long int)l_abs(val->tv_usec));
908 	else
909 	    sprintf(buf, "%ld.%06ld", (long int)val->tv_sec, (long int)l_abs(val->tv_usec));
910 	return buf;
911 }
912 
913 /*-----------------------------------------------------------------------
914  * correct the current time by an offset by setting the time rigorously
915  */
916 static void
917 set_time(
918 	 struct timeval *offset
919 	 )
920 {
921 	struct timeval the_time;
922 
923 	if (no_set)
924 	    return;
925 
926 	LPRINTF("set_time: %s ", pr_timeval(offset));
927 	syslog(LOG_NOTICE, "setting time (offset %s)", pr_timeval(offset));
928 
929 	if (gettimeofday(&the_time, 0L) == -1)
930 	{
931 		perror("gettimeofday()");
932 	}
933 	else
934 	{
935 		timeradd(&the_time, offset);
936 		if (settimeofday(&the_time, 0L) == -1)
937 		{
938 			perror("settimeofday()");
939 		}
940 	}
941 }
942 
943 /*-----------------------------------------------------------------------
944  * slew the time by a given offset
945  */
946 static void
947 adj_time(
948 	 long offset
949 	 )
950 {
951 	struct timeval time_offset;
952 
953 	if (no_set)
954 	    return;
955 
956 	time_offset.tv_sec  = offset / 1000000;
957 	time_offset.tv_usec = offset % 1000000;
958 
959 	LPRINTF("adj_time: %ld us ", (long int)offset);
960 	if (adjtime(&time_offset, 0L) == -1)
961 	    perror("adjtime()");
962 }
963 
964 /*-----------------------------------------------------------------------
965  * read in a possibly previously written drift value
966  */
967 static void
968 read_drift(
969 	   const char *drift_file
970 	   )
971 {
972 	FILE *df;
973 
974 	df = fopen(drift_file, "r");
975 	if (df != NULL)
976 	{
977 		int idrift = 0, fdrift = 0;
978 
979 		fscanf(df, "%4d.%03d", &idrift, &fdrift);
980 		fclose(df);
981 		LPRINTF("read_drift: %d.%03d ppm ", idrift, fdrift);
982 
983 		accum_drift = idrift << USECSCALE;
984 		fdrift     = (fdrift << USECSCALE) / 1000;
985 		accum_drift += fdrift & (1<<USECSCALE);
986 		LPRINTF("read_drift: drift_comp %ld ", (long int)accum_drift);
987 	}
988 }
989 
990 /*-----------------------------------------------------------------------
991  * write out the current drift value
992  */
993 static void
994 update_drift(
995 	     const char *drift_file,
996 	     long offset,
997 	     time_t reftime
998 	     )
999 {
1000 	FILE *df;
1001 
1002 	df = fopen(drift_file, "w");
1003 	if (df != NULL)
1004 	{
1005 		int idrift = R_SHIFT(accum_drift, USECSCALE);
1006 		int fdrift = accum_drift & ((1<<USECSCALE)-1);
1007 
1008 		LPRINTF("update_drift: drift_comp %ld ", (long int)accum_drift);
1009 		fdrift = (fdrift * 1000) / (1<<USECSCALE);
1010 		fprintf(df, "%4d.%03d %c%ld.%06ld %.24s\n", idrift, fdrift,
1011 			(offset < 0) ? '-' : '+', (long int)(l_abs(offset) / 1000000),
1012 			(long int)(l_abs(offset) % 1000000), asctime(localtime(&reftime)));
1013 		fclose(df);
1014 		LPRINTF("update_drift: %d.%03d ppm ", idrift, fdrift);
1015 	}
1016 }
1017 
1018 /*-----------------------------------------------------------------------
1019  * process adjustments derived from the DCF77 observation
1020  * (controls clock PLL)
1021  */
1022 static void
1023 adjust_clock(
1024 	     struct timeval *offset,
1025 	     const char *drift_file,
1026 	     time_t reftime
1027 	     )
1028 {
1029 	struct timeval toffset;
1030 	register long usecoffset;
1031 	int tmp;
1032 
1033 	if (no_set)
1034 	    return;
1035 
1036 	if (skip_adjust)
1037 	{
1038 		skip_adjust = 0;
1039 		return;
1040 	}
1041 
1042 	toffset = *offset;
1043 	toffset.tv_sec  = l_abs(toffset.tv_sec);
1044 	toffset.tv_usec = l_abs(toffset.tv_usec);
1045 	if (timercmp(&toffset, &max_adj_offset, >))
1046 	{
1047 		/*
1048 		 * hopeless - set the clock - and clear the timing
1049 		 */
1050 		set_time(offset);
1051 		clock_adjust = 0;
1052 		skip_adjust  = 1;
1053 		return;
1054 	}
1055 
1056 	usecoffset   = offset->tv_sec * 1000000 + offset->tv_usec;
1057 
1058 	clock_adjust = R_SHIFT(usecoffset, TIMECONSTANT);	/* adjustment to make for next period */
1059 
1060 	tmp = 0;
1061 	while (adjustments > (1 << tmp))
1062 	    tmp++;
1063 	adjustments = 0;
1064 	if (tmp > FREQ_WEIGHT)
1065 	    tmp = FREQ_WEIGHT;
1066 
1067 	accum_drift  += R_SHIFT(usecoffset << USECSCALE, TIMECONSTANT+TIMECONSTANT+FREQ_WEIGHT-tmp);
1068 
1069 	if (accum_drift > MAX_DRIFT)		/* clamp into interval */
1070 	    accum_drift = MAX_DRIFT;
1071 	else
1072 	    if (accum_drift < -MAX_DRIFT)
1073 		accum_drift = -MAX_DRIFT;
1074 
1075 	update_drift(drift_file, usecoffset, reftime);
1076 	LPRINTF("clock_adjust: %s, clock_adjust %ld, drift_comp %ld(%ld) ",
1077 		pr_timeval(offset),(long int) R_SHIFT(clock_adjust, USECSCALE),
1078 		(long int)R_SHIFT(accum_drift, USECSCALE), (long int)accum_drift);
1079 }
1080 
1081 /*-----------------------------------------------------------------------
1082  * adjust the clock by a small mount to simulate frequency correction
1083  */
1084 static void
1085 periodic_adjust(
1086 		void
1087 		)
1088 {
1089 	register long adjustment;
1090 
1091 	adjustments++;
1092 
1093 	adjustment = R_SHIFT(clock_adjust, PHASE_WEIGHT);
1094 
1095 	clock_adjust -= adjustment;
1096 
1097 	adjustment += R_SHIFT(accum_drift, USECSCALE+ADJINTERVAL);
1098 
1099 	adj_time(adjustment);
1100 }
1101 
1102 /*-----------------------------------------------------------------------
1103  * control synchronisation status (warnings) and do periodic adjusts
1104  * (frequency control simulation)
1105  */
1106 static void
1107 tick(
1108      int signum
1109      )
1110 {
1111 	static unsigned long last_notice = 0;
1112 
1113 #if !defined(HAVE_SIGACTION) && !defined(HAVE_SIGVEC)
1114 	(void)signal(SIGALRM, tick);
1115 #endif
1116 
1117 	periodic_adjust();
1118 
1119 	ticks += 1<<ADJINTERVAL;
1120 
1121 	if ((ticks - last_sync) > MAX_UNSYNC)
1122 	{
1123 		/*
1124 		 * not getting time for a while
1125 		 */
1126 		if (sync_state == SYNC)
1127 		{
1128 			/*
1129 			 * completely lost information
1130 			 */
1131 			sync_state = NO_SYNC;
1132 			syslog(LOG_INFO, "DCF77 reception lost (timeout)");
1133 			last_notice = ticks;
1134 		}
1135 		else
1136 		    /*
1137 		     * in NO_SYNC state - look whether its time to speak up again
1138 		     */
1139 		    if ((ticks - last_notice) > NOTICE_INTERVAL)
1140 		    {
1141 			    syslog(LOG_NOTICE, "still not synchronized to DCF77 - check receiver/signal");
1142 			    last_notice = ticks;
1143 		    }
1144 	}
1145 
1146 #ifndef ITIMER_REAL
1147 	(void) alarm(1<<ADJINTERVAL);
1148 #endif
1149 }
1150 
1151 /*-----------------------------------------------------------------------
1152  * break association from terminal to avoid catching terminal
1153  * or process group related signals (-> daemon operation)
1154  */
1155 static void
1156 detach(
1157        void
1158        )
1159 {
1160 #   ifdef HAVE_DAEMON
1161 	daemon(0, 0);
1162 #   else /* not HAVE_DAEMON */
1163 	if (fork())
1164 	    exit(0);
1165 
1166 	{
1167 		u_long s;
1168 		int max_fd;
1169 
1170 #if defined(HAVE_SYSCONF) && defined(_SC_OPEN_MAX)
1171 		max_fd = sysconf(_SC_OPEN_MAX);
1172 #else /* HAVE_SYSCONF && _SC_OPEN_MAX */
1173 		max_fd = getdtablesize();
1174 #endif /* HAVE_SYSCONF && _SC_OPEN_MAX */
1175 		for (s = 0; s < max_fd; s++)
1176 		    (void) close((int)s);
1177 		(void) open("/", 0);
1178 		(void) dup2(0, 1);
1179 		(void) dup2(0, 2);
1180 #ifdef SYS_DOMAINOS
1181 		{
1182 			uid_$t puid;
1183 			status_$t st;
1184 
1185 			proc2_$who_am_i(&puid);
1186 			proc2_$make_server(&puid, &st);
1187 		}
1188 #endif /* SYS_DOMAINOS */
1189 #if defined(HAVE_SETPGID) || defined(HAVE_SETSID)
1190 # ifdef HAVE_SETSID
1191 		if (setsid() == (pid_t)-1)
1192 		    syslog(LOG_ERR, "dcfd: setsid(): %m");
1193 # else
1194 		if (setpgid(0, 0) == -1)
1195 		    syslog(LOG_ERR, "dcfd: setpgid(): %m");
1196 # endif
1197 #else /* HAVE_SETPGID || HAVE_SETSID */
1198 		{
1199 			int fid;
1200 
1201 			fid = open("/dev/tty", 2);
1202 			if (fid >= 0)
1203 			{
1204 				(void) ioctl(fid, (u_long) TIOCNOTTY, (char *) 0);
1205 				(void) close(fid);
1206 			}
1207 # ifdef HAVE_SETPGRP_0
1208 			(void) setpgrp();
1209 # else /* HAVE_SETPGRP_0 */
1210 			(void) setpgrp(0, getpid());
1211 # endif /* HAVE_SETPGRP_0 */
1212 		}
1213 #endif /* HAVE_SETPGID || HAVE_SETSID */
1214 	}
1215 #endif /* not HAVE_DAEMON */
1216 }
1217 
1218 /*-----------------------------------------------------------------------
1219  * list possible arguments and options
1220  */
1221 static void
1222 usage(
1223       char *program
1224       )
1225 {
1226   fprintf(stderr, "usage: %s [-n] [-f] [-l] [-t] [-i] [-o] [-d <drift_file>] [-D <input delay>] <device>\n", program);
1227 	fprintf(stderr, "\t-n              do not change time\n");
1228 	fprintf(stderr, "\t-i              interactive\n");
1229 	fprintf(stderr, "\t-t              trace (print all datagrams)\n");
1230 	fprintf(stderr, "\t-f              print all databits (includes PTB private data)\n");
1231 	fprintf(stderr, "\t-l              print loop filter debug information\n");
1232 	fprintf(stderr, "\t-o              print offet average for current minute\n");
1233 	fprintf(stderr, "\t-Y              make internal Y2K checks then exit\n");	/* Y2KFixes */
1234 	fprintf(stderr, "\t-d <drift_file> specify alternate drift file\n");
1235 	fprintf(stderr, "\t-D <input delay>specify delay from input edge to processing in micro seconds\n");
1236 }
1237 
1238 /*-----------------------------------------------------------------------
1239  * check_y2k() - internal check of Y2K logic
1240  *	(a lot of this logic lifted from ../ntpd/check_y2k.c)
1241  */
1242 static int
1243 check_y2k( void )
1244 {
1245     int  year;			/* current working year */
1246     int  year0 = 1900;		/* sarting year for NTP time */
1247     int  yearend;		/* ending year we test for NTP time.
1248 				    * 32-bit systems: through 2036, the
1249 				      **year in which NTP time overflows.
1250 				    * 64-bit systems: a reasonable upper
1251 				      **limit (well, maybe somewhat beyond
1252 				      **reasonable, but well before the
1253 				      **max time, by which time the earth
1254 				      **will be dead.) */
1255     time_t Time;
1256     struct tm LocalTime;
1257 
1258     int Fatals, Warnings;
1259 #define Error(year) if ( (year)>=2036 && LocalTime.tm_year < 110 ) \
1260 	Warnings++; else Fatals++
1261 
1262     Fatals = Warnings = 0;
1263 
1264     Time = time( (time_t *)NULL );
1265     LocalTime = *localtime( &Time );
1266 
1267     year = ( sizeof( u_long ) > 4 ) 	/* save max span using year as temp */
1268 		? ( 400 * 3 ) 		/* three greater gregorian cycles */
1269 		: ((int)(0x7FFFFFFF / 365.242 / 24/60/60)* 2 ); /*32-bit limit*/
1270 			/* NOTE: will automacially expand test years on
1271 			 * 64 bit machines.... this may cause some of the
1272 			 * existing ntp logic to fail for years beyond
1273 			 * 2036 (the current 32-bit limit). If all checks
1274 			 * fail ONLY beyond year 2036 you may ignore such
1275 			 * errors, at least for a decade or so. */
1276     yearend = year0 + year;
1277 
1278     year = 1900+YEAR_PIVOT;
1279     printf( "  starting year %04d\n", (int) year );
1280     printf( "  ending year   %04d\n", (int) yearend );
1281 
1282     for ( ; year < yearend; year++ )
1283     {
1284 	clocktime_t  ct;
1285 	time_t	     Observed;
1286 	time_t	     Expected;
1287 	unsigned     Flag;
1288 	unsigned long t;
1289 
1290 	ct.day = 1;
1291 	ct.month = 1;
1292 	ct.year = year;
1293 	ct.hour = ct.minute = ct.second = ct.usecond = 0;
1294 	ct.utcoffset = 0;
1295 	ct.flags = 0;
1296 
1297 	Flag = 0;
1298  	Observed = dcf_to_unixtime( &ct, &Flag );
1299 		/* seems to be a clone of parse_to_unixtime() with
1300 		 * *a minor difference to arg2 type */
1301 	if ( ct.year != year )
1302 	{
1303 	    fprintf( stdout,
1304 	       "%04d: dcf_to_unixtime(,%d) CORRUPTED ct.year: was %d\n",
1305 	       (int)year, (int)Flag, (int)ct.year );
1306 	    Error(year);
1307 	    break;
1308 	}
1309 	t = julian0(year) - julian0(1970);	/* Julian day from 1970 */
1310 	Expected = t * 24 * 60 * 60;
1311 	if ( Observed != Expected  ||  Flag )
1312 	{   /* time difference */
1313 	    fprintf( stdout,
1314 	       "%04d: dcf_to_unixtime(,%d) FAILURE: was=%lu s/b=%lu  (%ld)\n",
1315 	       year, (int)Flag,
1316 	       (unsigned long)Observed, (unsigned long)Expected,
1317 	       ((long)Observed - (long)Expected) );
1318 	    Error(year);
1319 	    break;
1320 	}
1321 
1322 	if ( year >= YEAR_PIVOT+1900 )
1323 	{
1324 	    /* check year % 100 code we put into dcf_to_unixtime() */
1325 	    ct.year = year % 100;
1326 	    Flag = 0;
1327 
1328 	    Observed = dcf_to_unixtime( &ct, &Flag );
1329 
1330 	    if ( Observed != Expected  ||  Flag )
1331 	    {   /* time difference */
1332 		fprintf( stdout,
1333 "%04d: dcf_to_unixtime(%d,%d) FAILURE: was=%lu s/b=%lu  (%ld)\n",
1334 		   year, (int)ct.year, (int)Flag,
1335 		   (unsigned long)Observed, (unsigned long)Expected,
1336 		   ((long)Observed - (long)Expected) );
1337 		Error(year);
1338 		break;
1339 	    }
1340 
1341 	    /* check year - 1900 code we put into dcf_to_unixtime() */
1342 	    ct.year = year - 1900;
1343 	    Flag = 0;
1344 
1345 	    Observed = dcf_to_unixtime( &ct, &Flag );
1346 
1347 	    if ( Observed != Expected  ||  Flag ) {   /* time difference */
1348 		    fprintf( stdout,
1349 			     "%04d: dcf_to_unixtime(%d,%d) FAILURE: was=%lu s/b=%lu  (%ld)\n",
1350 			     year, (int)ct.year, (int)Flag,
1351 			     (unsigned long)Observed, (unsigned long)Expected,
1352 			     ((long)Observed - (long)Expected) );
1353 		    Error(year);
1354 		break;
1355 	    }
1356 
1357 
1358 	}
1359     }
1360 
1361     return ( Fatals );
1362 }
1363 
1364 /*--------------------------------------------------
1365  * rawdcf_init - set up modem lines for RAWDCF receivers
1366  */
1367 #if defined(TIOCMSET) && (defined(TIOCM_DTR) || defined(CIOCM_DTR))
1368 static void
1369 rawdcf_init(
1370 	int fd
1371 	)
1372 {
1373 	/*
1374 	 * You can use the RS232 to supply the power for a DCF77 receiver.
1375 	 * Here a voltage between the DTR and the RTS line is used. Unfortunately
1376 	 * the name has changed from CIOCM_DTR to TIOCM_DTR recently.
1377 	 */
1378 
1379 #ifdef TIOCM_DTR
1380 	int sl232 = TIOCM_DTR;	/* turn on DTR for power supply */
1381 #else
1382 	int sl232 = CIOCM_DTR;	/* turn on DTR for power supply */
1383 #endif
1384 
1385 	if (ioctl(fd, TIOCMSET, (caddr_t)&sl232) == -1)
1386 	{
1387 		syslog(LOG_NOTICE, "rawdcf_init: WARNING: ioctl(fd, TIOCMSET, [C|T]IOCM_DTR): %m");
1388 	}
1389 }
1390 #else
1391 static void
1392 rawdcf_init(
1393 	    int fd
1394 	)
1395 {
1396 	syslog(LOG_NOTICE, "rawdcf_init: WARNING: OS interface incapable of setting DTR to power DCF modules");
1397 }
1398 #endif  /* DTR initialisation type */
1399 
1400 /*-----------------------------------------------------------------------
1401  * main loop - argument interpreter / setup / main loop
1402  */
1403 int
1404 main(
1405      int argc,
1406      char **argv
1407      )
1408 {
1409 	unsigned char c;
1410 	char **a = argv;
1411 	int  ac = argc;
1412 	char *file = NULL;
1413 	const char *drift_file = "/etc/dcfd.drift";
1414 	int fd;
1415 	int offset = 15;
1416 	int offsets = 0;
1417 	int delay = DEFAULT_DELAY;	/* average delay from input edge to time stamping */
1418 	int trace = 0;
1419 	int errs = 0;
1420 
1421 	/*
1422 	 * process arguments
1423 	 */
1424 	while (--ac)
1425 	{
1426 		char *arg = *++a;
1427 		if (*arg == '-')
1428 		    while ((c = *++arg))
1429 			switch (c)
1430 			{
1431 			    case 't':
1432 				trace = 1;
1433 				interactive = 1;
1434 				break;
1435 
1436 			    case 'f':
1437 				offset = 0;
1438 				interactive = 1;
1439 				break;
1440 
1441 			    case 'l':
1442 				loop_filter_debug = 1;
1443 				offsets = 1;
1444 				interactive = 1;
1445 				break;
1446 
1447 			    case 'n':
1448 				no_set = 1;
1449 				break;
1450 
1451 			    case 'o':
1452 				offsets = 1;
1453 				interactive = 1;
1454 				break;
1455 
1456 			    case 'i':
1457 				interactive = 1;
1458 				break;
1459 
1460 			    case 'D':
1461 				if (ac > 1)
1462 				{
1463 					delay = atoi(*++a);
1464 					ac--;
1465 				}
1466 				else
1467 				{
1468 					fprintf(stderr, "%s: -D requires integer argument\n", argv[0]);
1469 					errs=1;
1470 				}
1471 				break;
1472 
1473 			    case 'd':
1474 				if (ac > 1)
1475 				{
1476 					drift_file = *++a;
1477 					ac--;
1478 				}
1479 				else
1480 				{
1481 					fprintf(stderr, "%s: -d requires file name argument\n", argv[0]);
1482 					errs=1;
1483 				}
1484 				break;
1485 
1486 			    case 'Y':
1487 				errs=check_y2k();
1488 				exit( errs ? 1 : 0 );
1489 
1490 			    default:
1491 				fprintf(stderr, "%s: unknown option -%c\n", argv[0], c);
1492 				errs=1;
1493 				break;
1494 			}
1495 		else
1496 		    if (file == NULL)
1497 			file = arg;
1498 		    else
1499 		    {
1500 			    fprintf(stderr, "%s: device specified twice\n", argv[0]);
1501 			    errs=1;
1502 		    }
1503 	}
1504 
1505 	if (errs)
1506 	{
1507 		usage(argv[0]);
1508 		exit(1);
1509 	}
1510 	else
1511 	    if (file == NULL)
1512 	    {
1513 		    fprintf(stderr, "%s: device not specified\n", argv[0]);
1514 		    usage(argv[0]);
1515 		    exit(1);
1516 	    }
1517 
1518 	errs = LINES+1;
1519 
1520 	/*
1521 	 * get access to DCF77 tty port
1522 	 */
1523 	fd = open(file, O_RDONLY);
1524 	if (fd == -1)
1525 	{
1526 		perror(file);
1527 		exit(1);
1528 	}
1529 	else
1530 	{
1531 		int i, rrc;
1532 		struct timeval t, tt, tlast;
1533 		struct timeval timeout;
1534 		struct timeval phase;
1535 		struct timeval time_offset;
1536 		char pbuf[61];		/* printable version */
1537 		char buf[61];		/* raw data */
1538 		clocktime_t clock_time;	/* wall clock time */
1539 		time_t utc_time = 0;
1540 		time_t last_utc_time = 0;
1541 		long usecerror = 0;
1542 		long lasterror = 0;
1543 #if defined(HAVE_TERMIOS_H) || defined(STREAM)
1544 		struct termios term;
1545 #else  /* not HAVE_TERMIOS_H || STREAM */
1546 # if defined(HAVE_TERMIO_H) || defined(HAVE_SYSV_TTYS)
1547 		struct termio term;
1548 # endif/* HAVE_TERMIO_H || HAVE_SYSV_TTYS */
1549 #endif /* not HAVE_TERMIOS_H || STREAM */
1550 		unsigned int rtc = CVT_NONE;
1551 
1552 		rawdcf_init(fd);
1553 
1554 		timeout.tv_sec  = 1;
1555 		timeout.tv_usec = 500000;
1556 
1557 		phase.tv_sec    = 0;
1558 		phase.tv_usec   = delay;
1559 
1560 		/*
1561 		 * setup TTY (50 Baud, Read, 8Bit, No Hangup, 1 character IO)
1562 		 */
1563 		if (TTY_GETATTR(fd,  &term) == -1)
1564 		{
1565 			perror("tcgetattr");
1566 			exit(1);
1567 		}
1568 
1569 		memset(term.c_cc, 0, sizeof(term.c_cc));
1570 		term.c_cc[VMIN] = 1;
1571 #ifdef NO_PARENB_IGNPAR
1572 		term.c_cflag = CS8|CREAD|CLOCAL;
1573 #else
1574 		term.c_cflag = CS8|CREAD|CLOCAL|PARENB;
1575 #endif
1576 		term.c_iflag = IGNPAR;
1577 		term.c_oflag = 0;
1578 		term.c_lflag = 0;
1579 
1580 		cfsetispeed(&term, B50);
1581 		cfsetospeed(&term, B50);
1582 
1583 		if (TTY_SETATTR(fd, &term) == -1)
1584 		{
1585 			perror("tcsetattr");
1586 			exit(1);
1587 		}
1588 
1589 		/*
1590 		 * lose terminal if in daemon operation
1591 		 */
1592 		if (!interactive)
1593 		    detach();
1594 
1595 		/*
1596 		 * get syslog() initialized
1597 		 */
1598 #ifdef LOG_DAEMON
1599 		openlog("dcfd", LOG_PID, LOG_DAEMON);
1600 #else
1601 		openlog("dcfd", LOG_PID);
1602 #endif
1603 
1604 		/*
1605 		 * setup periodic operations (state control / frequency control)
1606 		 */
1607 #ifdef HAVE_SIGACTION
1608 		{
1609 			struct sigaction act;
1610 
1611 # ifdef HAVE_SA_SIGACTION_IN_STRUCT_SIGACTION
1612 			act.sa_sigaction = (void (*) P((int, siginfo_t *, void *)))0;
1613 # endif /* HAVE_SA_SIGACTION_IN_STRUCT_SIGACTION */
1614 			act.sa_handler   = tick;
1615 			sigemptyset(&act.sa_mask);
1616 			act.sa_flags     = 0;
1617 
1618 			if (sigaction(SIGALRM, &act, (struct sigaction *)0) == -1)
1619 			{
1620 				syslog(LOG_ERR, "sigaction(SIGALRM): %m");
1621 				exit(1);
1622 			}
1623 		}
1624 #else
1625 #ifdef HAVE_SIGVEC
1626 		{
1627 			struct sigvec vec;
1628 
1629 			vec.sv_handler   = tick;
1630 			vec.sv_mask      = 0;
1631 			vec.sv_flags     = 0;
1632 
1633 			if (sigvec(SIGALRM, &vec, (struct sigvec *)0) == -1)
1634 			{
1635 				syslog(LOG_ERR, "sigvec(SIGALRM): %m");
1636 				exit(1);
1637 			}
1638 		}
1639 #else
1640 		(void) signal(SIGALRM, tick);
1641 #endif
1642 #endif
1643 
1644 #ifdef ITIMER_REAL
1645 		{
1646 			struct itimerval it;
1647 
1648 			it.it_interval.tv_sec  = 1<<ADJINTERVAL;
1649 			it.it_interval.tv_usec = 0;
1650 			it.it_value.tv_sec     = 1<<ADJINTERVAL;
1651 			it.it_value.tv_usec    = 0;
1652 
1653 			if (setitimer(ITIMER_REAL, &it, (struct itimerval *)0) == -1)
1654 			{
1655 				syslog(LOG_ERR, "setitimer: %m");
1656 				exit(1);
1657 			}
1658 		}
1659 #else
1660 		(void) alarm(1<<ADJINTERVAL);
1661 #endif
1662 
1663 		PRINTF("  DCF77 monitor %s - Copyright (C) 1993-2005 by Frank Kardel\n\n", revision);
1664 
1665 		pbuf[60] = '\0';
1666 		for ( i = 0; i < 60; i++)
1667 		    pbuf[i] = '.';
1668 
1669 		read_drift(drift_file);
1670 
1671 		/*
1672 		 * what time is it now (for interval measurement)
1673 		 */
1674 		gettimeofday(&tlast, 0L);
1675 		i = 0;
1676 		/*
1677 		 * loop until input trouble ...
1678 		 */
1679 		do
1680 		{
1681 			/*
1682 			 * get an impulse
1683 			 */
1684 			while ((rrc = read(fd, &c, 1)) == 1)
1685 			{
1686 				gettimeofday(&t, 0L);
1687 				tt = t;
1688 				timersub(&t, &tlast);
1689 
1690 				if (errs > LINES)
1691 				{
1692 					PRINTF("  %s", &"PTB private....RADMLSMin....PHour..PMDay..DayMonthYear....P\n"[offset]);
1693 					PRINTF("  %s", &"---------------RADMLS1248124P124812P1248121241248112481248P\n"[offset]);
1694 					errs = 0;
1695 				}
1696 
1697 				/*
1698 				 * timeout -> possible minute mark -> interpretation
1699 				 */
1700 				if (timercmp(&t, &timeout, >))
1701 				{
1702 					PRINTF("%c %.*s ", pat[i % (sizeof(pat)-1)], 59 - offset, &pbuf[offset]);
1703 
1704 					if ((rtc = cvt_rawdcf((unsigned char *)buf, i, &clock_time)) != CVT_OK)
1705 					{
1706 						/*
1707 						 * this data was bad - well - forget synchronisation for now
1708 						 */
1709 						PRINTF("\n");
1710 						if (sync_state == SYNC)
1711 						{
1712 							sync_state = NO_SYNC;
1713 							syslog(LOG_INFO, "DCF77 reception lost (bad data)");
1714 						}
1715 						errs++;
1716 					}
1717 					else
1718 					    if (trace)
1719 					    {
1720 						    PRINTF("\r  %.*s ", 59 - offset, &buf[offset]);
1721 					    }
1722 
1723 
1724 					buf[0] = c;
1725 
1726 					/*
1727 					 * collect first character
1728 					 */
1729 					if (((c^0xFF)+1) & (c^0xFF))
1730 					    pbuf[0] = '?';
1731 					else
1732 					    pbuf[0] = type(c) ? '#' : '-';
1733 
1734 					for ( i = 1; i < 60; i++)
1735 					    pbuf[i] = '.';
1736 
1737 					i = 0;
1738 				}
1739 				else
1740 				{
1741 					/*
1742 					 * collect character
1743 					 */
1744 					buf[i] = c;
1745 
1746 					/*
1747 					 * initial guess (usually correct)
1748 					 */
1749 					if (((c^0xFF)+1) & (c^0xFF))
1750 					    pbuf[i] = '?';
1751 					else
1752 					    pbuf[i] = type(c) ? '#' : '-';
1753 
1754 					PRINTF("%c %.*s ", pat[i % (sizeof(pat)-1)], 59 - offset, &pbuf[offset]);
1755 				}
1756 
1757 				if (i == 0 && rtc == CVT_OK)
1758 				{
1759 					/*
1760 					 * we got a good time code here - try to convert it to
1761 					 * UTC
1762 					 */
1763 					if ((utc_time = dcf_to_unixtime(&clock_time, &rtc)) == -1)
1764 					{
1765 						PRINTF("*** BAD CONVERSION\n");
1766 					}
1767 
1768 					if (utc_time != (last_utc_time + 60))
1769 					{
1770 						/*
1771 						 * well, two successive sucessful telegrams are not 60 seconds
1772 						 * apart
1773 						 */
1774 						PRINTF("*** NO MINUTE INC\n");
1775 						if (sync_state == SYNC)
1776 						{
1777 							sync_state = NO_SYNC;
1778 							syslog(LOG_INFO, "DCF77 reception lost (data mismatch)");
1779 						}
1780 						errs++;
1781 						rtc = CVT_FAIL|CVT_BADTIME|CVT_BADDATE;
1782 					}
1783 					else
1784 					    usecerror = 0;
1785 
1786 					last_utc_time = utc_time;
1787 				}
1788 
1789 				if (rtc == CVT_OK)
1790 				{
1791 					if (i == 0)
1792 					{
1793 						/*
1794 						 * valid time code - determine offset and
1795 						 * note regained reception
1796 						 */
1797 						last_sync = ticks;
1798 						if (sync_state == NO_SYNC)
1799 						{
1800 							syslog(LOG_INFO, "receiving DCF77");
1801 						}
1802 						else
1803 						{
1804 							/*
1805 							 * we had at least one minute SYNC - thus
1806 							 * last error is valid
1807 							 */
1808 							time_offset.tv_sec  = lasterror / 1000000;
1809 							time_offset.tv_usec = lasterror % 1000000;
1810 							adjust_clock(&time_offset, drift_file, utc_time);
1811 						}
1812 						sync_state = SYNC;
1813 					}
1814 
1815 					time_offset.tv_sec  = utc_time + i;
1816 					time_offset.tv_usec = 0;
1817 
1818 					timeradd(&time_offset, &phase);
1819 
1820 					usecerror += (time_offset.tv_sec - tt.tv_sec) * 1000000 + time_offset.tv_usec
1821 						-tt.tv_usec;
1822 
1823 					/*
1824 					 * output interpreted DCF77 data
1825 					 */
1826 					PRINTF(offsets ? "%s, %2ld:%02ld:%02d, %ld.%02ld.%02ld, <%s%s%s%s> (%c%ld.%06lds)" :
1827 					       "%s, %2ld:%02ld:%02d, %ld.%02ld.%02ld, <%s%s%s%s>",
1828 					       wday[clock_time.wday],
1829 					       clock_time.hour, clock_time.minute, i, clock_time.day, clock_time.month,
1830 					       clock_time.year,
1831 					       (clock_time.flags & DCFB_ALTERNATE) ? "R" : "_",
1832 					       (clock_time.flags & DCFB_ANNOUNCE) ? "A" : "_",
1833 					       (clock_time.flags & DCFB_DST) ? "D" : "_",
1834 					       (clock_time.flags & DCFB_LEAP) ? "L" : "_",
1835 					       (lasterror < 0) ? '-' : '+', l_abs(lasterror) / 1000000, l_abs(lasterror) % 1000000
1836 					       );
1837 
1838 					if (trace && (i == 0))
1839 					{
1840 						PRINTF("\n");
1841 						errs++;
1842 					}
1843 					lasterror = usecerror / (i+1);
1844 				}
1845 				else
1846 				{
1847 					lasterror = 0; /* we cannot calculate phase errors on bad reception */
1848 				}
1849 
1850 				PRINTF("\r");
1851 
1852 				if (i < 60)
1853 				{
1854 					i++;
1855 				}
1856 
1857 				tlast = tt;
1858 
1859 				if (interactive)
1860 				    fflush(stdout);
1861 			}
1862 		} while ((rrc == -1) && (errno == EINTR));
1863 
1864 		/*
1865 		 * lost IO - sorry guys
1866 		 */
1867 		syslog(LOG_ERR, "TERMINATING - cannot read from device %s (%m)", file);
1868 
1869 		(void)close(fd);
1870 	}
1871 
1872 	closelog();
1873 
1874 	return 0;
1875 }
1876 
1877 /*
1878  * History:
1879  *
1880  * dcfd.c,v
1881  * Revision 4.18  2005/10/07 22:08:18  kardel
1882  * make dcfd.c compile on NetBSD 3.99.9 again (configure/sigvec compatibility fix)
1883  *
1884  * Revision 4.17.2.1  2005/10/03 19:15:16  kardel
1885  * work around configure not detecting a missing sigvec compatibility
1886  * interface on NetBSD 3.99.9 and above
1887  *
1888  * Revision 4.17  2005/08/10 10:09:44  kardel
1889  * output revision information
1890  *
1891  * Revision 4.16  2005/08/10 06:33:25  kardel
1892  * cleanup warnings
1893  *
1894  * Revision 4.15  2005/08/10 06:28:45  kardel
1895  * fix setting of baud rate
1896  *
1897  * Revision 4.14  2005/04/16 17:32:10  kardel
1898  * update copyright
1899  *
1900  * Revision 4.13  2004/11/14 15:29:41  kardel
1901  * support PPSAPI, upgrade Copyright to Berkeley style
1902  *
1903  */
1904