xref: /freebsd/contrib/ntp/parseutil/dcfd.c (revision 788ca347b816afd83b2885e0c79aeeb88649b2ab)
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 long max_adj_offset_usec = 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@%ld FAILED\n",
591 				 (u_int)*s, (long)(s - buffer)));
592 			*s = (unsigned char)~0;
593 			rtc = CVT_FAIL|CVT_BADFMT;
594 		}
595 		s++;
596 	}
597 
598 	/*
599 	 * first cutoff estimate (average bit count - must be between both
600 	 * maxima)
601 	 */
602 	if (lowmax)
603 	{
604 		cutoff /= lowmax;
605 	}
606 	else
607 	{
608 		cutoff = 4;	/* doesn't really matter - it'll fail anyway, but gives error output */
609 	}
610 
611 	dprintf(("parse: cvt_rawdcf: average bit count: %d\n", cutoff));
612 
613 	lowmax = 0;  /* weighted sum */
614 	highmax = 0; /* bitcount */
615 
616 	/*
617 	 * collect weighted sum of lower bits (left of initial guess)
618 	 */
619 	dprintf(("parse: cvt_rawdcf: histogram:"));
620 	for (i = 0; i <= cutoff; i++)
621 	{
622 		lowmax  += histbuf[i] * i;
623 		highmax += histbuf[i];
624 		dprintf((" %d", histbuf[i]));
625 	}
626 	dprintf((" <M>"));
627 
628 	/*
629 	 * round up
630 	 */
631 	lowmax += highmax / 2;
632 
633 	/*
634 	 * calculate lower bit maximum (weighted sum / bit count)
635 	 *
636 	 * avoid divide by zero
637 	 */
638 	if (highmax)
639 	{
640 		lowmax /= highmax;
641 	}
642 	else
643 	{
644 		lowmax = 0;
645 	}
646 
647 	highmax = 0; /* weighted sum of upper bits counts */
648 	cutoff = 0;  /* bitcount */
649 
650 	/*
651 	 * collect weighted sum of lower bits (right of initial guess)
652 	 */
653 	for (; i < BITS; i++)
654 	{
655 		highmax+=histbuf[i] * i;
656 		cutoff +=histbuf[i];
657 		dprintf((" %d", histbuf[i]));
658 	}
659 	dprintf(("\n"));
660 
661 	/*
662 	 * determine upper maximum (weighted sum / bit count)
663 	 */
664 	if (cutoff)
665 	{
666 		highmax /= cutoff;
667 	}
668 	else
669 	{
670 		highmax = BITS-1;
671 	}
672 
673 	/*
674 	 * following now holds:
675 	 * lowmax <= cutoff(initial guess) <= highmax
676 	 * best cutoff is the minimum nearest to higher bits
677 	 */
678 
679 	/*
680 	 * find the minimum between lowmax and highmax (detecting
681 	 * possibly a minimum span)
682 	 */
683 	span = cutoff = lowmax;
684 	for (i = lowmax; i <= highmax; i++)
685 	{
686 		if (histbuf[cutoff] > histbuf[i])
687 		{
688 			/*
689 			 * got a new minimum move beginning of minimum (cutoff) and
690 			 * end of minimum (span) there
691 			 */
692 			cutoff = span = i;
693 		}
694 		else
695 		    if (histbuf[cutoff] == histbuf[i])
696 		    {
697 			    /*
698 			     * minimum not better yet - but it spans more than
699 			     * one bit value - follow it
700 			     */
701 			    span = i;
702 		    }
703 	}
704 
705 	/*
706 	 * cutoff point for 1/0 decision is the middle of the minimum section
707 	 * in the histogram
708 	 */
709 	cutoff = (cutoff + span) / 2;
710 
711 	dprintf(("parse: cvt_rawdcf: lower maximum %d, higher maximum %d, cutoff %d\n", lowmax, highmax, cutoff));
712 
713 	/*
714 	 * convert the bit counts to symbolic 1/0 information for data conversion
715 	 */
716 	s = buffer;
717 	while ((s < e) && *c && *b)
718 	{
719 		if (*s == (unsigned char)~0)
720 		{
721 			/*
722 			 * invalid character
723 			 */
724 			*s = '?';
725 		}
726 		else
727 		{
728 			/*
729 			 * symbolic 1/0 representation
730 			 */
731 			*s = (*s >= cutoff) ? *b : *c;
732 		}
733 		s++;
734 		b++;
735 		c++;
736 	}
737 
738 	/*
739 	 * if everything went well so far return the result of the symbolic
740 	 * conversion routine else just the accumulated errors
741 	 */
742 	if (rtc != CVT_NONE)
743 	{
744 		PRINTF("%-30s", "*** BAD DATA");
745 	}
746 
747 	return (rtc == CVT_NONE) ? convert_rawdcf(buffer, size, clock_time) : rtc;
748 }
749 
750 /*-----------------------------------------------------------------------
751  * convert a wall clock time description of DCF77 to a Unix time (seconds
752  * since 1.1. 1970 UTC)
753  */
754 static time_t
755 dcf_to_unixtime(
756 		clocktime_t   *clock_time,
757 		unsigned *cvtrtc
758 		)
759 {
760 #define SETRTC(_X_)	{ if (cvtrtc) *cvtrtc = (_X_); }
761 	static int days_of_month[] =
762 	{
763 		0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
764 	};
765 	register int i;
766 	time_t t;
767 
768 	/*
769 	 * map 2 digit years to 19xx (DCF77 is a 20th century item)
770 	 */
771 	if ( clock_time->year < YEAR_PIVOT ) 	/* in case of	   Y2KFixes [ */
772 		clock_time->year += 100;	/* *year%100, make tm_year */
773 						/* *(do we need this?) */
774 	if ( clock_time->year < YEAR_BREAK )	/* (failsafe if) */
775 	    clock_time->year += 1900;				/* Y2KFixes ] */
776 
777 	/*
778 	 * must have been a really bad year code - drop it
779 	 */
780 	if (clock_time->year < (YEAR_PIVOT + 1900) )		/* Y2KFixes */
781 	{
782 		SETRTC(CVT_FAIL|CVT_BADDATE);
783 		return -1;
784 	}
785 	/*
786 	 * sorry, slow section here - but it's not time critical anyway
787 	 */
788 
789 	/*
790 	 * calculate days since 1970 (watching leap years)
791 	 */
792 	t = julian0( clock_time->year ) - julian0( 1970 );
793 
794   				/* month */
795 	if (clock_time->month <= 0 || clock_time->month > 12)
796 	{
797 		SETRTC(CVT_FAIL|CVT_BADDATE);
798 		return -1;		/* bad month */
799 	}
800 				/* adjust current leap year */
801 #if 0
802 	if (clock_time->month < 3 && days_per_year(clock_time->year) == 366)
803 	    t--;
804 #endif
805 
806 	/*
807 	 * collect days from months excluding the current one
808 	 */
809 	for (i = 1; i < clock_time->month; i++)
810 	{
811 		t += days_of_month[i];
812 	}
813 				/* day */
814 	if (clock_time->day < 1 || ((clock_time->month == 2 && days_per_year(clock_time->year) == 366) ?
815 			       clock_time->day > 29 : clock_time->day > days_of_month[clock_time->month]))
816 	{
817 		SETRTC(CVT_FAIL|CVT_BADDATE);
818 		return -1;		/* bad day */
819 	}
820 
821 	/*
822 	 * collect days from date excluding the current one
823 	 */
824 	t += clock_time->day - 1;
825 
826 				/* hour */
827 	if (clock_time->hour < 0 || clock_time->hour >= 24)
828 	{
829 		SETRTC(CVT_FAIL|CVT_BADTIME);
830 		return -1;		/* bad hour */
831 	}
832 
833 	/*
834 	 * calculate hours from 1. 1. 1970
835 	 */
836 	t = TIMES24(t) + clock_time->hour;
837 
838   				/* min */
839 	if (clock_time->minute < 0 || clock_time->minute > 59)
840 	{
841 		SETRTC(CVT_FAIL|CVT_BADTIME);
842 		return -1;		/* bad min */
843 	}
844 
845 	/*
846 	 * calculate minutes from 1. 1. 1970
847 	 */
848 	t = TIMES60(t) + clock_time->minute;
849 				/* sec */
850 
851 	/*
852 	 * calculate UTC in minutes
853 	 */
854 	t += clock_time->utcoffset;
855 
856 	if (clock_time->second < 0 || clock_time->second > 60)	/* allow for LEAPs */
857 	{
858 		SETRTC(CVT_FAIL|CVT_BADTIME);
859 		return -1;		/* bad sec */
860 	}
861 
862 	/*
863 	 * calculate UTC in seconds - phew !
864 	 */
865 	t  = TIMES60(t) + clock_time->second;
866 				/* done */
867 	return t;
868 }
869 
870 /*-----------------------------------------------------------------------
871  * cheap half baked 1/0 decision - for interactive operation only
872  */
873 static char
874 type(
875      unsigned int c
876      )
877 {
878 	c ^= 0xFF;
879 	return (c > 0xF);
880 }
881 
882 /*-----------------------------------------------------------------------
883  * week day representation
884  */
885 static const char *wday[8] =
886 {
887 	"??",
888 	"Mo",
889 	"Tu",
890 	"We",
891 	"Th",
892 	"Fr",
893 	"Sa",
894 	"Su"
895 };
896 
897 /*-----------------------------------------------------------------------
898  * generate a string representation for a timeval
899  */
900 static char *
901 pr_timeval(
902 	struct timeval *val
903 	)
904 {
905 	static char buf[20];
906 
907 	if (val->tv_sec == 0)
908 		snprintf(buf, sizeof(buf), "%c0.%06ld",
909 			 (val->tv_usec < 0) ? '-' : '+',
910 			 (long int)l_abs(val->tv_usec));
911 	else
912 		snprintf(buf, sizeof(buf), "%ld.%06ld",
913 			 (long int)val->tv_sec,
914 			 (long int)l_abs(val->tv_usec));
915 	return buf;
916 }
917 
918 /*-----------------------------------------------------------------------
919  * correct the current time by an offset by setting the time rigorously
920  */
921 static void
922 set_time(
923 	 struct timeval *offset
924 	 )
925 {
926 	struct timeval the_time;
927 
928 	if (no_set)
929 	    return;
930 
931 	LPRINTF("set_time: %s ", pr_timeval(offset));
932 	syslog(LOG_NOTICE, "setting time (offset %s)", pr_timeval(offset));
933 
934 	if (gettimeofday(&the_time, 0L) == -1)
935 	{
936 		perror("gettimeofday()");
937 	}
938 	else
939 	{
940 		timeradd(&the_time, offset);
941 		if (settimeofday(&the_time, 0L) == -1)
942 		{
943 			perror("settimeofday()");
944 		}
945 	}
946 }
947 
948 /*-----------------------------------------------------------------------
949  * slew the time by a given offset
950  */
951 static void
952 adj_time(
953 	 long offset
954 	 )
955 {
956 	struct timeval time_offset;
957 
958 	if (no_set)
959 	    return;
960 
961 	time_offset.tv_sec  = offset / 1000000;
962 	time_offset.tv_usec = offset % 1000000;
963 
964 	LPRINTF("adj_time: %ld us ", (long int)offset);
965 	if (adjtime(&time_offset, 0L) == -1)
966 	    perror("adjtime()");
967 }
968 
969 /*-----------------------------------------------------------------------
970  * read in a possibly previously written drift value
971  */
972 static void
973 read_drift(
974 	   const char *drift_file
975 	   )
976 {
977 	FILE *df;
978 
979 	df = fopen(drift_file, "r");
980 	if (df != NULL)
981 	{
982 		int idrift = 0, fdrift = 0;
983 
984 		fscanf(df, "%4d.%03d", &idrift, &fdrift);
985 		fclose(df);
986 		LPRINTF("read_drift: %d.%03d ppm ", idrift, fdrift);
987 
988 		accum_drift = idrift << USECSCALE;
989 		fdrift     = (fdrift << USECSCALE) / 1000;
990 		accum_drift += fdrift & (1<<USECSCALE);
991 		LPRINTF("read_drift: drift_comp %ld ", (long int)accum_drift);
992 	}
993 }
994 
995 /*-----------------------------------------------------------------------
996  * write out the current drift value
997  */
998 static void
999 update_drift(
1000 	     const char *drift_file,
1001 	     long offset,
1002 	     time_t reftime
1003 	     )
1004 {
1005 	FILE *df;
1006 
1007 	df = fopen(drift_file, "w");
1008 	if (df != NULL)
1009 	{
1010 		int idrift = R_SHIFT(accum_drift, USECSCALE);
1011 		int fdrift = accum_drift & ((1<<USECSCALE)-1);
1012 
1013 		LPRINTF("update_drift: drift_comp %ld ", (long int)accum_drift);
1014 		fdrift = (fdrift * 1000) / (1<<USECSCALE);
1015 		fprintf(df, "%4d.%03d %c%ld.%06ld %.24s\n", idrift, fdrift,
1016 			(offset < 0) ? '-' : '+', (long int)(l_abs(offset) / 1000000),
1017 			(long int)(l_abs(offset) % 1000000), asctime(localtime(&reftime)));
1018 		fclose(df);
1019 		LPRINTF("update_drift: %d.%03d ppm ", idrift, fdrift);
1020 	}
1021 }
1022 
1023 /*-----------------------------------------------------------------------
1024  * process adjustments derived from the DCF77 observation
1025  * (controls clock PLL)
1026  */
1027 static void
1028 adjust_clock(
1029 	     struct timeval *offset,
1030 	     const char *drift_file,
1031 	     time_t reftime
1032 	     )
1033 {
1034 	struct timeval toffset;
1035 	register long usecoffset;
1036 	int tmp;
1037 
1038 	if (no_set)
1039 	    return;
1040 
1041 	if (skip_adjust)
1042 	{
1043 		skip_adjust = 0;
1044 		return;
1045 	}
1046 
1047 	toffset = *offset;
1048 	toffset.tv_sec  = l_abs(toffset.tv_sec);
1049 	toffset.tv_usec = l_abs(toffset.tv_usec);
1050 	if (toffset.tv_sec ||
1051 	    (!toffset.tv_sec && toffset.tv_usec > max_adj_offset_usec))
1052 	{
1053 		/*
1054 		 * hopeless - set the clock - and clear the timing
1055 		 */
1056 		set_time(offset);
1057 		clock_adjust = 0;
1058 		skip_adjust  = 1;
1059 		return;
1060 	}
1061 
1062 	usecoffset   = offset->tv_sec * 1000000 + offset->tv_usec;
1063 
1064 	clock_adjust = R_SHIFT(usecoffset, TIMECONSTANT);	/* adjustment to make for next period */
1065 
1066 	tmp = 0;
1067 	while (adjustments > (1 << tmp))
1068 	    tmp++;
1069 	adjustments = 0;
1070 	if (tmp > FREQ_WEIGHT)
1071 	    tmp = FREQ_WEIGHT;
1072 
1073 	accum_drift  += R_SHIFT(usecoffset << USECSCALE, TIMECONSTANT+TIMECONSTANT+FREQ_WEIGHT-tmp);
1074 
1075 	if (accum_drift > MAX_DRIFT)		/* clamp into interval */
1076 	    accum_drift = MAX_DRIFT;
1077 	else
1078 	    if (accum_drift < -MAX_DRIFT)
1079 		accum_drift = -MAX_DRIFT;
1080 
1081 	update_drift(drift_file, usecoffset, reftime);
1082 	LPRINTF("clock_adjust: %s, clock_adjust %ld, drift_comp %ld(%ld) ",
1083 		pr_timeval(offset),(long int) R_SHIFT(clock_adjust, USECSCALE),
1084 		(long int)R_SHIFT(accum_drift, USECSCALE), (long int)accum_drift);
1085 }
1086 
1087 /*-----------------------------------------------------------------------
1088  * adjust the clock by a small mount to simulate frequency correction
1089  */
1090 static void
1091 periodic_adjust(
1092 		void
1093 		)
1094 {
1095 	register long adjustment;
1096 
1097 	adjustments++;
1098 
1099 	adjustment = R_SHIFT(clock_adjust, PHASE_WEIGHT);
1100 
1101 	clock_adjust -= adjustment;
1102 
1103 	adjustment += R_SHIFT(accum_drift, USECSCALE+ADJINTERVAL);
1104 
1105 	adj_time(adjustment);
1106 }
1107 
1108 /*-----------------------------------------------------------------------
1109  * control synchronisation status (warnings) and do periodic adjusts
1110  * (frequency control simulation)
1111  */
1112 static void
1113 tick(
1114      int signum
1115      )
1116 {
1117 	static unsigned long last_notice = 0;
1118 
1119 #if !defined(HAVE_SIGACTION) && !defined(HAVE_SIGVEC)
1120 	(void)signal(SIGALRM, tick);
1121 #endif
1122 
1123 	periodic_adjust();
1124 
1125 	ticks += 1<<ADJINTERVAL;
1126 
1127 	if ((ticks - last_sync) > MAX_UNSYNC)
1128 	{
1129 		/*
1130 		 * not getting time for a while
1131 		 */
1132 		if (sync_state == SYNC)
1133 		{
1134 			/*
1135 			 * completely lost information
1136 			 */
1137 			sync_state = NO_SYNC;
1138 			syslog(LOG_INFO, "DCF77 reception lost (timeout)");
1139 			last_notice = ticks;
1140 		}
1141 		else
1142 		    /*
1143 		     * in NO_SYNC state - look whether its time to speak up again
1144 		     */
1145 		    if ((ticks - last_notice) > NOTICE_INTERVAL)
1146 		    {
1147 			    syslog(LOG_NOTICE, "still not synchronized to DCF77 - check receiver/signal");
1148 			    last_notice = ticks;
1149 		    }
1150 	}
1151 
1152 #ifndef ITIMER_REAL
1153 	(void) alarm(1<<ADJINTERVAL);
1154 #endif
1155 }
1156 
1157 /*-----------------------------------------------------------------------
1158  * break association from terminal to avoid catching terminal
1159  * or process group related signals (-> daemon operation)
1160  */
1161 static void
1162 detach(
1163        void
1164        )
1165 {
1166 #   ifdef HAVE_DAEMON
1167 	daemon(0, 0);
1168 #   else /* not HAVE_DAEMON */
1169 	if (fork())
1170 	    exit(0);
1171 
1172 	{
1173 		u_long s;
1174 		int max_fd;
1175 
1176 #if defined(HAVE_SYSCONF) && defined(_SC_OPEN_MAX)
1177 		max_fd = sysconf(_SC_OPEN_MAX);
1178 #else /* HAVE_SYSCONF && _SC_OPEN_MAX */
1179 		max_fd = getdtablesize();
1180 #endif /* HAVE_SYSCONF && _SC_OPEN_MAX */
1181 		for (s = 0; s < max_fd; s++)
1182 		    (void) close((int)s);
1183 		(void) open("/", 0);
1184 		(void) dup2(0, 1);
1185 		(void) dup2(0, 2);
1186 #ifdef SYS_DOMAINOS
1187 		{
1188 			uid_$t puid;
1189 			status_$t st;
1190 
1191 			proc2_$who_am_i(&puid);
1192 			proc2_$make_server(&puid, &st);
1193 		}
1194 #endif /* SYS_DOMAINOS */
1195 #if defined(HAVE_SETPGID) || defined(HAVE_SETSID)
1196 # ifdef HAVE_SETSID
1197 		if (setsid() == (pid_t)-1)
1198 		    syslog(LOG_ERR, "dcfd: setsid(): %m");
1199 # else
1200 		if (setpgid(0, 0) == -1)
1201 		    syslog(LOG_ERR, "dcfd: setpgid(): %m");
1202 # endif
1203 #else /* HAVE_SETPGID || HAVE_SETSID */
1204 		{
1205 			int fid;
1206 
1207 			fid = open("/dev/tty", 2);
1208 			if (fid >= 0)
1209 			{
1210 				(void) ioctl(fid, (u_long) TIOCNOTTY, (char *) 0);
1211 				(void) close(fid);
1212 			}
1213 # ifdef HAVE_SETPGRP_0
1214 			(void) setpgrp();
1215 # else /* HAVE_SETPGRP_0 */
1216 			(void) setpgrp(0, getpid());
1217 # endif /* HAVE_SETPGRP_0 */
1218 		}
1219 #endif /* HAVE_SETPGID || HAVE_SETSID */
1220 	}
1221 #endif /* not HAVE_DAEMON */
1222 }
1223 
1224 /*-----------------------------------------------------------------------
1225  * list possible arguments and options
1226  */
1227 static void
1228 usage(
1229       char *program
1230       )
1231 {
1232   fprintf(stderr, "usage: %s [-n] [-f] [-l] [-t] [-i] [-o] [-d <drift_file>] [-D <input delay>] <device>\n", program);
1233 	fprintf(stderr, "\t-n              do not change time\n");
1234 	fprintf(stderr, "\t-i              interactive\n");
1235 	fprintf(stderr, "\t-t              trace (print all datagrams)\n");
1236 	fprintf(stderr, "\t-f              print all databits (includes PTB private data)\n");
1237 	fprintf(stderr, "\t-l              print loop filter debug information\n");
1238 	fprintf(stderr, "\t-o              print offet average for current minute\n");
1239 	fprintf(stderr, "\t-Y              make internal Y2K checks then exit\n");	/* Y2KFixes */
1240 	fprintf(stderr, "\t-d <drift_file> specify alternate drift file\n");
1241 	fprintf(stderr, "\t-D <input delay>specify delay from input edge to processing in micro seconds\n");
1242 }
1243 
1244 /*-----------------------------------------------------------------------
1245  * check_y2k() - internal check of Y2K logic
1246  *	(a lot of this logic lifted from ../ntpd/check_y2k.c)
1247  */
1248 static int
1249 check_y2k( void )
1250 {
1251     int  year;			/* current working year */
1252     int  year0 = 1900;		/* sarting year for NTP time */
1253     int  yearend;		/* ending year we test for NTP time.
1254 				    * 32-bit systems: through 2036, the
1255 				      **year in which NTP time overflows.
1256 				    * 64-bit systems: a reasonable upper
1257 				      **limit (well, maybe somewhat beyond
1258 				      **reasonable, but well before the
1259 				      **max time, by which time the earth
1260 				      **will be dead.) */
1261     time_t Time;
1262     struct tm LocalTime;
1263 
1264     int Fatals, Warnings;
1265 #define Error(year) if ( (year)>=2036 && LocalTime.tm_year < 110 ) \
1266 	Warnings++; else Fatals++
1267 
1268     Fatals = Warnings = 0;
1269 
1270     Time = time( (time_t *)NULL );
1271     LocalTime = *localtime( &Time );
1272 
1273     year = ( sizeof( u_long ) > 4 ) 	/* save max span using year as temp */
1274 		? ( 400 * 3 ) 		/* three greater gregorian cycles */
1275 		: ((int)(0x7FFFFFFF / 365.242 / 24/60/60)* 2 ); /*32-bit limit*/
1276 			/* NOTE: will automacially expand test years on
1277 			 * 64 bit machines.... this may cause some of the
1278 			 * existing ntp logic to fail for years beyond
1279 			 * 2036 (the current 32-bit limit). If all checks
1280 			 * fail ONLY beyond year 2036 you may ignore such
1281 			 * errors, at least for a decade or so. */
1282     yearend = year0 + year;
1283 
1284     year = 1900+YEAR_PIVOT;
1285     printf( "  starting year %04d\n", (int) year );
1286     printf( "  ending year   %04d\n", (int) yearend );
1287 
1288     for ( ; year < yearend; year++ )
1289     {
1290 	clocktime_t  ct;
1291 	time_t	     Observed;
1292 	time_t	     Expected;
1293 	unsigned     Flag;
1294 	unsigned long t;
1295 
1296 	ct.day = 1;
1297 	ct.month = 1;
1298 	ct.year = year;
1299 	ct.hour = ct.minute = ct.second = ct.usecond = 0;
1300 	ct.utcoffset = 0;
1301 	ct.flags = 0;
1302 
1303 	Flag = 0;
1304  	Observed = dcf_to_unixtime( &ct, &Flag );
1305 		/* seems to be a clone of parse_to_unixtime() with
1306 		 * *a minor difference to arg2 type */
1307 	if ( ct.year != year )
1308 	{
1309 	    fprintf( stdout,
1310 	       "%04d: dcf_to_unixtime(,%d) CORRUPTED ct.year: was %d\n",
1311 	       (int)year, (int)Flag, (int)ct.year );
1312 	    Error(year);
1313 	    break;
1314 	}
1315 	t = julian0(year) - julian0(1970);	/* Julian day from 1970 */
1316 	Expected = t * 24 * 60 * 60;
1317 	if ( Observed != Expected  ||  Flag )
1318 	{   /* time difference */
1319 	    fprintf( stdout,
1320 	       "%04d: dcf_to_unixtime(,%d) FAILURE: was=%lu s/b=%lu  (%ld)\n",
1321 	       year, (int)Flag,
1322 	       (unsigned long)Observed, (unsigned long)Expected,
1323 	       ((long)Observed - (long)Expected) );
1324 	    Error(year);
1325 	    break;
1326 	}
1327 
1328     }
1329 
1330     return ( Fatals );
1331 }
1332 
1333 /*--------------------------------------------------
1334  * rawdcf_init - set up modem lines for RAWDCF receivers
1335  */
1336 #if defined(TIOCMSET) && (defined(TIOCM_DTR) || defined(CIOCM_DTR))
1337 static void
1338 rawdcf_init(
1339 	int fd
1340 	)
1341 {
1342 	/*
1343 	 * You can use the RS232 to supply the power for a DCF77 receiver.
1344 	 * Here a voltage between the DTR and the RTS line is used. Unfortunately
1345 	 * the name has changed from CIOCM_DTR to TIOCM_DTR recently.
1346 	 */
1347 
1348 #ifdef TIOCM_DTR
1349 	int sl232 = TIOCM_DTR;	/* turn on DTR for power supply */
1350 #else
1351 	int sl232 = CIOCM_DTR;	/* turn on DTR for power supply */
1352 #endif
1353 
1354 	if (ioctl(fd, TIOCMSET, (caddr_t)&sl232) == -1)
1355 	{
1356 		syslog(LOG_NOTICE, "rawdcf_init: WARNING: ioctl(fd, TIOCMSET, [C|T]IOCM_DTR): %m");
1357 	}
1358 }
1359 #else
1360 static void
1361 rawdcf_init(
1362 	    int fd
1363 	)
1364 {
1365 	syslog(LOG_NOTICE, "rawdcf_init: WARNING: OS interface incapable of setting DTR to power DCF modules");
1366 }
1367 #endif  /* DTR initialisation type */
1368 
1369 /*-----------------------------------------------------------------------
1370  * main loop - argument interpreter / setup / main loop
1371  */
1372 int
1373 main(
1374      int argc,
1375      char **argv
1376      )
1377 {
1378 	unsigned char c;
1379 	char **a = argv;
1380 	int  ac = argc;
1381 	char *file = NULL;
1382 	const char *drift_file = "/etc/dcfd.drift";
1383 	int fd;
1384 	int offset = 15;
1385 	int offsets = 0;
1386 	int delay = DEFAULT_DELAY;	/* average delay from input edge to time stamping */
1387 	int trace = 0;
1388 	int errs = 0;
1389 
1390 	/*
1391 	 * process arguments
1392 	 */
1393 	while (--ac)
1394 	{
1395 		char *arg = *++a;
1396 		if (*arg == '-')
1397 		    while ((c = *++arg))
1398 			switch (c)
1399 			{
1400 			    case 't':
1401 				trace = 1;
1402 				interactive = 1;
1403 				break;
1404 
1405 			    case 'f':
1406 				offset = 0;
1407 				interactive = 1;
1408 				break;
1409 
1410 			    case 'l':
1411 				loop_filter_debug = 1;
1412 				offsets = 1;
1413 				interactive = 1;
1414 				break;
1415 
1416 			    case 'n':
1417 				no_set = 1;
1418 				break;
1419 
1420 			    case 'o':
1421 				offsets = 1;
1422 				interactive = 1;
1423 				break;
1424 
1425 			    case 'i':
1426 				interactive = 1;
1427 				break;
1428 
1429 			    case 'D':
1430 				if (ac > 1)
1431 				{
1432 					delay = atoi(*++a);
1433 					ac--;
1434 				}
1435 				else
1436 				{
1437 					fprintf(stderr, "%s: -D requires integer argument\n", argv[0]);
1438 					errs=1;
1439 				}
1440 				break;
1441 
1442 			    case 'd':
1443 				if (ac > 1)
1444 				{
1445 					drift_file = *++a;
1446 					ac--;
1447 				}
1448 				else
1449 				{
1450 					fprintf(stderr, "%s: -d requires file name argument\n", argv[0]);
1451 					errs=1;
1452 				}
1453 				break;
1454 
1455 			    case 'Y':
1456 				errs=check_y2k();
1457 				exit( errs ? 1 : 0 );
1458 
1459 			    default:
1460 				fprintf(stderr, "%s: unknown option -%c\n", argv[0], c);
1461 				errs=1;
1462 				break;
1463 			}
1464 		else
1465 		    if (file == NULL)
1466 			file = arg;
1467 		    else
1468 		    {
1469 			    fprintf(stderr, "%s: device specified twice\n", argv[0]);
1470 			    errs=1;
1471 		    }
1472 	}
1473 
1474 	if (errs)
1475 	{
1476 		usage(argv[0]);
1477 		exit(1);
1478 	}
1479 	else
1480 	    if (file == NULL)
1481 	    {
1482 		    fprintf(stderr, "%s: device not specified\n", argv[0]);
1483 		    usage(argv[0]);
1484 		    exit(1);
1485 	    }
1486 
1487 	errs = LINES+1;
1488 
1489 	/*
1490 	 * get access to DCF77 tty port
1491 	 */
1492 	fd = open(file, O_RDONLY);
1493 	if (fd == -1)
1494 	{
1495 		perror(file);
1496 		exit(1);
1497 	}
1498 	else
1499 	{
1500 		int i, rrc;
1501 		struct timeval t, tt, tlast;
1502 		struct timeval timeout;
1503 		struct timeval phase;
1504 		struct timeval time_offset;
1505 		char pbuf[61];		/* printable version */
1506 		char buf[61];		/* raw data */
1507 		clocktime_t clock_time;	/* wall clock time */
1508 		time_t utc_time = 0;
1509 		time_t last_utc_time = 0;
1510 		long usecerror = 0;
1511 		long lasterror = 0;
1512 #if defined(HAVE_TERMIOS_H) || defined(STREAM)
1513 		struct termios term;
1514 #else  /* not HAVE_TERMIOS_H || STREAM */
1515 # if defined(HAVE_TERMIO_H) || defined(HAVE_SYSV_TTYS)
1516 		struct termio term;
1517 # endif/* HAVE_TERMIO_H || HAVE_SYSV_TTYS */
1518 #endif /* not HAVE_TERMIOS_H || STREAM */
1519 		unsigned int rtc = CVT_NONE;
1520 
1521 		rawdcf_init(fd);
1522 
1523 		timeout.tv_sec  = 1;
1524 		timeout.tv_usec = 500000;
1525 
1526 		phase.tv_sec    = 0;
1527 		phase.tv_usec   = delay;
1528 
1529 		/*
1530 		 * setup TTY (50 Baud, Read, 8Bit, No Hangup, 1 character IO)
1531 		 */
1532 		if (TTY_GETATTR(fd,  &term) == -1)
1533 		{
1534 			perror("tcgetattr");
1535 			exit(1);
1536 		}
1537 
1538 		memset(term.c_cc, 0, sizeof(term.c_cc));
1539 		term.c_cc[VMIN] = 1;
1540 #ifdef NO_PARENB_IGNPAR
1541 		term.c_cflag = CS8|CREAD|CLOCAL;
1542 #else
1543 		term.c_cflag = CS8|CREAD|CLOCAL|PARENB;
1544 #endif
1545 		term.c_iflag = IGNPAR;
1546 		term.c_oflag = 0;
1547 		term.c_lflag = 0;
1548 
1549 		cfsetispeed(&term, B50);
1550 		cfsetospeed(&term, B50);
1551 
1552 		if (TTY_SETATTR(fd, &term) == -1)
1553 		{
1554 			perror("tcsetattr");
1555 			exit(1);
1556 		}
1557 
1558 		/*
1559 		 * lose terminal if in daemon operation
1560 		 */
1561 		if (!interactive)
1562 		    detach();
1563 
1564 		/*
1565 		 * get syslog() initialized
1566 		 */
1567 #ifdef LOG_DAEMON
1568 		openlog("dcfd", LOG_PID, LOG_DAEMON);
1569 #else
1570 		openlog("dcfd", LOG_PID);
1571 #endif
1572 
1573 		/*
1574 		 * setup periodic operations (state control / frequency control)
1575 		 */
1576 #ifdef HAVE_SIGACTION
1577 		{
1578 			struct sigaction act;
1579 
1580 # ifdef HAVE_SA_SIGACTION_IN_STRUCT_SIGACTION
1581 			act.sa_sigaction = (void (*) (int, siginfo_t *, void *))0;
1582 # endif /* HAVE_SA_SIGACTION_IN_STRUCT_SIGACTION */
1583 			act.sa_handler   = tick;
1584 			sigemptyset(&act.sa_mask);
1585 			act.sa_flags     = 0;
1586 
1587 			if (sigaction(SIGALRM, &act, (struct sigaction *)0) == -1)
1588 			{
1589 				syslog(LOG_ERR, "sigaction(SIGALRM): %m");
1590 				exit(1);
1591 			}
1592 		}
1593 #else
1594 #ifdef HAVE_SIGVEC
1595 		{
1596 			struct sigvec vec;
1597 
1598 			vec.sv_handler   = tick;
1599 			vec.sv_mask      = 0;
1600 			vec.sv_flags     = 0;
1601 
1602 			if (sigvec(SIGALRM, &vec, (struct sigvec *)0) == -1)
1603 			{
1604 				syslog(LOG_ERR, "sigvec(SIGALRM): %m");
1605 				exit(1);
1606 			}
1607 		}
1608 #else
1609 		(void) signal(SIGALRM, tick);
1610 #endif
1611 #endif
1612 
1613 #ifdef ITIMER_REAL
1614 		{
1615 			struct itimerval it;
1616 
1617 			it.it_interval.tv_sec  = 1<<ADJINTERVAL;
1618 			it.it_interval.tv_usec = 0;
1619 			it.it_value.tv_sec     = 1<<ADJINTERVAL;
1620 			it.it_value.tv_usec    = 0;
1621 
1622 			if (setitimer(ITIMER_REAL, &it, (struct itimerval *)0) == -1)
1623 			{
1624 				syslog(LOG_ERR, "setitimer: %m");
1625 				exit(1);
1626 			}
1627 		}
1628 #else
1629 		(void) alarm(1<<ADJINTERVAL);
1630 #endif
1631 
1632 		PRINTF("  DCF77 monitor %s - Copyright (C) 1993-2005 by Frank Kardel\n\n", revision);
1633 
1634 		pbuf[60] = '\0';
1635 		for ( i = 0; i < 60; i++)
1636 		    pbuf[i] = '.';
1637 
1638 		read_drift(drift_file);
1639 
1640 		/*
1641 		 * what time is it now (for interval measurement)
1642 		 */
1643 		gettimeofday(&tlast, 0L);
1644 		i = 0;
1645 		/*
1646 		 * loop until input trouble ...
1647 		 */
1648 		do
1649 		{
1650 			/*
1651 			 * get an impulse
1652 			 */
1653 			while ((rrc = read(fd, &c, 1)) == 1)
1654 			{
1655 				gettimeofday(&t, 0L);
1656 				tt = t;
1657 				timersub(&t, &tlast);
1658 
1659 				if (errs > LINES)
1660 				{
1661 					PRINTF("  %s", &"PTB private....RADMLSMin....PHour..PMDay..DayMonthYear....P\n"[offset]);
1662 					PRINTF("  %s", &"---------------RADMLS1248124P124812P1248121241248112481248P\n"[offset]);
1663 					errs = 0;
1664 				}
1665 
1666 				/*
1667 				 * timeout -> possible minute mark -> interpretation
1668 				 */
1669 				if (timercmp(&t, &timeout, >))
1670 				{
1671 					PRINTF("%c %.*s ", pat[i % (sizeof(pat)-1)], 59 - offset, &pbuf[offset]);
1672 
1673 					if ((rtc = cvt_rawdcf((unsigned char *)buf, i, &clock_time)) != CVT_OK)
1674 					{
1675 						/*
1676 						 * this data was bad - well - forget synchronisation for now
1677 						 */
1678 						PRINTF("\n");
1679 						if (sync_state == SYNC)
1680 						{
1681 							sync_state = NO_SYNC;
1682 							syslog(LOG_INFO, "DCF77 reception lost (bad data)");
1683 						}
1684 						errs++;
1685 					}
1686 					else
1687 					    if (trace)
1688 					    {
1689 						    PRINTF("\r  %.*s ", 59 - offset, &buf[offset]);
1690 					    }
1691 
1692 
1693 					buf[0] = c;
1694 
1695 					/*
1696 					 * collect first character
1697 					 */
1698 					if (((c^0xFF)+1) & (c^0xFF))
1699 					    pbuf[0] = '?';
1700 					else
1701 					    pbuf[0] = type(c) ? '#' : '-';
1702 
1703 					for ( i = 1; i < 60; i++)
1704 					    pbuf[i] = '.';
1705 
1706 					i = 0;
1707 				}
1708 				else
1709 				{
1710 					/*
1711 					 * collect character
1712 					 */
1713 					buf[i] = c;
1714 
1715 					/*
1716 					 * initial guess (usually correct)
1717 					 */
1718 					if (((c^0xFF)+1) & (c^0xFF))
1719 					    pbuf[i] = '?';
1720 					else
1721 					    pbuf[i] = type(c) ? '#' : '-';
1722 
1723 					PRINTF("%c %.*s ", pat[i % (sizeof(pat)-1)], 59 - offset, &pbuf[offset]);
1724 				}
1725 
1726 				if (i == 0 && rtc == CVT_OK)
1727 				{
1728 					/*
1729 					 * we got a good time code here - try to convert it to
1730 					 * UTC
1731 					 */
1732 					if ((utc_time = dcf_to_unixtime(&clock_time, &rtc)) == -1)
1733 					{
1734 						PRINTF("*** BAD CONVERSION\n");
1735 					}
1736 
1737 					if (utc_time != (last_utc_time + 60))
1738 					{
1739 						/*
1740 						 * well, two successive sucessful telegrams are not 60 seconds
1741 						 * apart
1742 						 */
1743 						PRINTF("*** NO MINUTE INC\n");
1744 						if (sync_state == SYNC)
1745 						{
1746 							sync_state = NO_SYNC;
1747 							syslog(LOG_INFO, "DCF77 reception lost (data mismatch)");
1748 						}
1749 						errs++;
1750 						rtc = CVT_FAIL|CVT_BADTIME|CVT_BADDATE;
1751 					}
1752 					else
1753 					    usecerror = 0;
1754 
1755 					last_utc_time = utc_time;
1756 				}
1757 
1758 				if (rtc == CVT_OK)
1759 				{
1760 					if (i == 0)
1761 					{
1762 						/*
1763 						 * valid time code - determine offset and
1764 						 * note regained reception
1765 						 */
1766 						last_sync = ticks;
1767 						if (sync_state == NO_SYNC)
1768 						{
1769 							syslog(LOG_INFO, "receiving DCF77");
1770 						}
1771 						else
1772 						{
1773 							/*
1774 							 * we had at least one minute SYNC - thus
1775 							 * last error is valid
1776 							 */
1777 							time_offset.tv_sec  = lasterror / 1000000;
1778 							time_offset.tv_usec = lasterror % 1000000;
1779 							adjust_clock(&time_offset, drift_file, utc_time);
1780 						}
1781 						sync_state = SYNC;
1782 					}
1783 
1784 					time_offset.tv_sec  = utc_time + i;
1785 					time_offset.tv_usec = 0;
1786 
1787 					timeradd(&time_offset, &phase);
1788 
1789 					usecerror += (time_offset.tv_sec - tt.tv_sec) * 1000000 + time_offset.tv_usec
1790 						-tt.tv_usec;
1791 
1792 					/*
1793 					 * output interpreted DCF77 data
1794 					 */
1795 					PRINTF(offsets ? "%s, %2ld:%02ld:%02d, %ld.%02ld.%02ld, <%s%s%s%s> (%c%ld.%06lds)" :
1796 					       "%s, %2ld:%02ld:%02d, %ld.%02ld.%02ld, <%s%s%s%s>",
1797 					       wday[clock_time.wday],
1798 					       clock_time.hour, clock_time.minute, i, clock_time.day, clock_time.month,
1799 					       clock_time.year,
1800 					       (clock_time.flags & DCFB_ALTERNATE) ? "R" : "_",
1801 					       (clock_time.flags & DCFB_ANNOUNCE) ? "A" : "_",
1802 					       (clock_time.flags & DCFB_DST) ? "D" : "_",
1803 					       (clock_time.flags & DCFB_LEAP) ? "L" : "_",
1804 					       (lasterror < 0) ? '-' : '+', l_abs(lasterror) / 1000000, l_abs(lasterror) % 1000000
1805 					       );
1806 
1807 					if (trace && (i == 0))
1808 					{
1809 						PRINTF("\n");
1810 						errs++;
1811 					}
1812 					lasterror = usecerror / (i+1);
1813 				}
1814 				else
1815 				{
1816 					lasterror = 0; /* we cannot calculate phase errors on bad reception */
1817 				}
1818 
1819 				PRINTF("\r");
1820 
1821 				if (i < 60)
1822 				{
1823 					i++;
1824 				}
1825 
1826 				tlast = tt;
1827 
1828 				if (interactive)
1829 				    fflush(stdout);
1830 			}
1831 		} while ((rrc == -1) && (errno == EINTR));
1832 
1833 		/*
1834 		 * lost IO - sorry guys
1835 		 */
1836 		syslog(LOG_ERR, "TERMINATING - cannot read from device %s (%m)", file);
1837 
1838 		(void)close(fd);
1839 	}
1840 
1841 	closelog();
1842 
1843 	return 0;
1844 }
1845 
1846 /*
1847  * History:
1848  *
1849  * dcfd.c,v
1850  * Revision 4.18  2005/10/07 22:08:18  kardel
1851  * make dcfd.c compile on NetBSD 3.99.9 again (configure/sigvec compatibility fix)
1852  *
1853  * Revision 4.17.2.1  2005/10/03 19:15:16  kardel
1854  * work around configure not detecting a missing sigvec compatibility
1855  * interface on NetBSD 3.99.9 and above
1856  *
1857  * Revision 4.17  2005/08/10 10:09:44  kardel
1858  * output revision information
1859  *
1860  * Revision 4.16  2005/08/10 06:33:25  kardel
1861  * cleanup warnings
1862  *
1863  * Revision 4.15  2005/08/10 06:28:45  kardel
1864  * fix setting of baud rate
1865  *
1866  * Revision 4.14  2005/04/16 17:32:10  kardel
1867  * update copyright
1868  *
1869  * Revision 4.13  2004/11/14 15:29:41  kardel
1870  * support PPSAPI, upgrade Copyright to Berkeley style
1871  *
1872  */
1873