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/contrib/ntp/parseutil/dcfd.c

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   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 Universität Erlangen-Nürnberg, 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
 133static char *revision = "4.18";
 134
 135/*
 136 * display received data (avoids also detaching from tty)
 137 */
 138static int interactive = 0;
 139
 140/*
 141 * display loopfilter (clock control) variables
 142 */
 143static int loop_filter_debug = 0;
 144
 145/*
 146 * do not set/adjust system time
 147 */
 148static 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
 163static int    sync_state = NO_SYNC;
 164static time_t last_sync;
 165
 166static unsigned long ticks = 0;
 167
 168static 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
 188static struct timeval max_adj_offset = { 0, 128000 };
 189
 190static long clock_adjust = 0;	/* current adjustment value (usec * 2^USECSCALE) */
 191static long accum_drift   = 0;	/* accumulated drift value  (usec / ADJINTERVAL) */
 192static long adjustments  = 0;
 193static 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
 203struct 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
 217typedef 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 */
 297static 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 */
 336static 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 */
 360static 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 */
 377static unsigned long
 378ext_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 */
 403static unsigned
 404pcheck(
 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 */
 429static unsigned long
 430convert_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 */
 516static unsigned long
 517cvt_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 */
 753static time_t
 754dcf_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 */
 872static char
 873type(
 874     unsigned int c
 875     )
 876{
 877	c ^= 0xFF;
 878	return (c > 0xF);
 879}
 880
 881/*-----------------------------------------------------------------------
 882 * week day representation
 883 */
 884static 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 */
 899static char *
 900pr_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 */
 916static void
 917set_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 */
 946static void
 947adj_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 */
 967static void
 968read_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 */
 993static void
 994update_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 */
1022static void
1023adjust_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 */
1084static void
1085periodic_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 */
1106static void
1107tick(
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 */
1155static void
1156detach(
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 */
1221static void
1222usage(
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 */
1242static int
1243check_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))
1368static void
1369rawdcf_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
1391static void
1392rawdcf_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 */
1403int
1404main(
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 */