Virgin import of ntpd 4.0.98fvendor/ntp/4.0.98f

1 files changed, 1850 insertions, 0 deletions

diff --git a/contrib/ntp/parseutil/dcfd.c b/contrib/ntp/parseutil/dcfd.c
new file mode 100644
index 000000000000..7d223de3cbbd
--- /dev/null
+++ b/contrib/ntp/parseutil/dcfd.c
@@ -0,0 +1,1850 @@
+/*
+ * /src/NTP/ntp-4/parseutil/dcfd.c,v 4.9 1999/02/28 13:06:27 kardel RELEASE_19990228_A
+ *  
+ * dcfd.c,v 4.9 1999/02/28 13:06:27 kardel RELEASE_19990228_A
+ *
+ * DCF77 100/200ms pulse synchronisation daemon program (via 50Baud serial line)
+ *
+ * Features:
+ *  DCF77 decoding
+ *  simple NTP loopfilter logic for local clock
+ *  interactive display for debugging
+ *
+ * Lacks:
+ *  Leap second handling (at that level you should switch to NTP Version 4 - really!)
+ *
+ * Copyright (C) 1995-1999 by Frank Kardel <kardel@acm.org>
+ * Copyright (C) 1993-1994 by Frank Kardel
+ * Friedrich-Alexander Universität Erlangen-Nürnberg, Germany
+ *                                    
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * This program may not be sold or used for profit without prior
+ * written consent of the author.
+ */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <unistd.h>
+#include <stdio.h>
+#include <fcntl.h>
+#include <sys/types.h>
+#include <sys/time.h>
+#include <signal.h>
+#include <syslog.h>
+#include <time.h>
+
+/*
+ * NTP compilation environment
+ */
+#include "ntp_stdlib.h"
+#include "ntpd.h"   /* indirectly include ntp.h to get YEAR_PIVOT   Y2KFixes */
+
+/*
+ * select which terminal handling to use (currently only SysV variants)
+ */
+#if defined(HAVE_TERMIOS_H) || defined(STREAM)
+#include <termios.h>
+#define TTY_GETATTR(_FD_, _ARG_) tcgetattr((_FD_), (_ARG_))
+#define TTY_SETATTR(_FD_, _ARG_) tcsetattr((_FD_), TCSANOW, (_ARG_))
+#else  /* not HAVE_TERMIOS_H || STREAM */
+# if defined(HAVE_TERMIO_H) || defined(HAVE_SYSV_TTYS)
+#  include <termio.h>
+#  define TTY_GETATTR(_FD_, _ARG_) ioctl((_FD_), TCGETA, (_ARG_))
+#  define TTY_SETATTR(_FD_, _ARG_) ioctl((_FD_), TCSETAW, (_ARG_))
+# endif/* HAVE_TERMIO_H || HAVE_SYSV_TTYS */
+#endif /* not HAVE_TERMIOS_H || STREAM */
+
+
+#ifndef TTY_GETATTR
+#include "Bletch: MUST DEFINE ONE OF 'HAVE_TERMIOS_H' or 'HAVE_TERMIO_H'"
+#endif
+
+#ifndef days_per_year
+#define days_per_year(_x_) (((_x_) % 4) ? 365 : (((_x_) % 400) ? 365 : 366))
+#endif
+
+#define timernormalize(_a_) \
+	if ((_a_)->tv_usec >= 1000000) \
+	{ \
+		(_a_)->tv_sec  += (_a_)->tv_usec / 1000000; \
+		(_a_)->tv_usec  = (_a_)->tv_usec % 1000000; \
+	} \
+	if ((_a_)->tv_usec < 0) \
+	{ \
+		(_a_)->tv_sec  -= 1 + (-(_a_)->tv_usec / 1000000); \
+		(_a_)->tv_usec = 999999 - (-(_a_)->tv_usec - 1); \
+	}
+
+#ifdef timeradd
+#undef timeradd
+#endif
+#define timeradd(_a_, _b_) \
+	(_a_)->tv_sec  += (_b_)->tv_sec; \
+	(_a_)->tv_usec += (_b_)->tv_usec; \
+	timernormalize((_a_))
+
+#ifdef timersub
+#undef timersub
+#endif
+#define timersub(_a_, _b_) \
+	(_a_)->tv_sec  -= (_b_)->tv_sec; \
+	(_a_)->tv_usec -= (_b_)->tv_usec; \
+	timernormalize((_a_))
+
+/*
+ * debug macros
+ */
+#define PRINTF if (interactive) printf
+#define LPRINTF if (interactive && loop_filter_debug) printf
+
+#ifdef DEBUG
+#define dprintf(_x_) LPRINTF _x_
+#else
+#define dprintf(_x_)
+#endif
+
+     extern int errno;
+
+/*
+ * display received data (avoids also detaching from tty)
+ */
+static int interactive = 0;
+
+/*
+ * display loopfilter (clock control) variables
+ */
+static int loop_filter_debug = 0;
+
+/*
+ * do not set/adjust system time
+ */
+static int no_set = 0;
+
+/*
+ * time that passes between start of DCF impulse and time stamping (fine
+ * adjustment) in microseconds (receiver/OS dependent)
+ */
+#define DEFAULT_DELAY	230000	/* rough estimate */
+
+/*
+ * The two states we can be in - eithe we receive nothing
+ * usable or we have the correct time
+ */
+#define NO_SYNC		0x01
+#define SYNC		0x02
+
+static int    sync_state = NO_SYNC;
+static time_t last_sync;
+
+static unsigned long ticks = 0;
+
+static char pat[] = "-\\|/";
+
+#define LINES		(24-2)	/* error lines after which the two headlines are repeated */
+
+#define MAX_UNSYNC	(10*60)	/* allow synchronisation loss for 10 minutes */
+#define NOTICE_INTERVAL (20*60)	/* mention missing synchronisation every 20 minutes */
+
+/*
+ * clock adjustment PLL - see NTP protocol spec (RFC1305) for details
+ */
+
+#define USECSCALE	10
+#define TIMECONSTANT	2
+#define ADJINTERVAL	0
+#define FREQ_WEIGHT	18
+#define PHASE_WEIGHT	7
+#define MAX_DRIFT	0x3FFFFFFF
+
+#define R_SHIFT(_X_, _Y_) (((_X_) < 0) ? -(-(_X_) >> (_Y_)) : ((_X_) >> (_Y_)))
+
+static struct timeval max_adj_offset = { 0, 128000 };
+
+static long clock_adjust = 0;	/* current adjustment value (usec * 2^USECSCALE) */
+static long accum_drift   = 0;	/* accumulated drift value  (usec / ADJINTERVAL) */
+static long adjustments  = 0;
+static char skip_adjust  = 1;	/* discard first adjustment (bad samples) */
+
+/*
+ * DCF77 state flags
+ */
+#define DCFB_ANNOUNCE           0x0001 /* switch time zone warning (DST switch) */
+#define DCFB_DST                0x0002 /* DST in effect */
+#define DCFB_LEAP		0x0004 /* LEAP warning (1 hour prior to occurence) */
+#define DCFB_ALTERNATE		0x0008 /* alternate antenna used */
+
+struct clocktime		/* clock time broken up from time code */
+{
+	long wday;		/* Day of week: 1: Monday - 7: Sunday */
+	long day;
+	long month;
+	long year;
+	long hour;
+	long minute;
+	long second;
+	long usecond;
+	long utcoffset;	/* in minutes */
+	long flags;		/* current clock status  (DCF77 state flags) */
+};
+
+typedef struct clocktime clocktime_t;
+
+/*
+ * (usually) quick constant multiplications
+ */
+#define TIMES10(_X_) (((_X_) << 3) + ((_X_) << 1))	/* *8 + *2 */
+#define TIMES24(_X_) (((_X_) << 4) + ((_X_) << 3))      /* *16 + *8 */
+#define TIMES60(_X_) ((((_X_) << 4)  - (_X_)) << 2)     /* *(16 - 1) *4 */
+/*
+ * generic l_abs() function
+ */
+#define l_abs(_x_)     (((_x_) < 0) ? -(_x_) : (_x_))
+
+/*
+ * conversion related return/error codes
+ */
+#define CVT_MASK	0x0000000F /* conversion exit code */
+#define   CVT_NONE	0x00000001 /* format not applicable */
+#define   CVT_FAIL	0x00000002 /* conversion failed - error code returned */
+#define   CVT_OK	0x00000004 /* conversion succeeded */
+#define CVT_BADFMT	0x00000010 /* general format error - (unparsable) */
+#define CVT_BADDATE	0x00000020 /* invalid date */
+#define CVT_BADTIME	0x00000040 /* invalid time */
+
+/*
+ * DCF77 raw time code
+ *
+ * From "Zur Zeit", Physikalisch-Technische Bundesanstalt (PTB), Braunschweig
+ * und Berlin, Maerz 1989
+ *
+ * Timecode transmission:
+ * AM:
+ *	time marks are send every second except for the second before the
+ *	next minute mark
+ *	time marks consist of a reduction of transmitter power to 25%
+ *	of the nominal level
+ *	the falling edge is the time indication (on time)
+ *	time marks of a 100ms duration constitute a logical 0
+ *	time marks of a 200ms duration constitute a logical 1
+ * FM:
+ *	see the spec. (basically a (non-)inverted psuedo random phase shift)
+ *
+ * Encoding:
+ * Second	Contents
+ * 0  - 10	AM: free, FM: 0
+ * 11 - 14	free
+ * 15		R     - alternate antenna
+ * 16		A1    - expect zone change (1 hour before)
+ * 17 - 18	Z1,Z2 - time zone
+ *		 0  0 illegal
+ *		 0  1 MEZ  (MET)
+ *		 1  0 MESZ (MED, MET DST)
+ *		 1  1 illegal
+ * 19		A2    - expect leap insertion/deletion (1 hour before)
+ * 20		S     - start of time code (1)
+ * 21 - 24	M1    - BCD (lsb first) Minutes
+ * 25 - 27	M10   - BCD (lsb first) 10 Minutes
+ * 28		P1    - Minute Parity (even)
+ * 29 - 32	H1    - BCD (lsb first) Hours
+ * 33 - 34      H10   - BCD (lsb first) 10 Hours
+ * 35		P2    - Hour Parity (even)
+ * 36 - 39	D1    - BCD (lsb first) Days
+ * 40 - 41	D10   - BCD (lsb first) 10 Days
+ * 42 - 44	DW    - BCD (lsb first) day of week (1: Monday -> 7: Sunday)
+ * 45 - 49	MO    - BCD (lsb first) Month
+ * 50           MO0   - 10 Months
+ * 51 - 53	Y1    - BCD (lsb first) Years
+ * 54 - 57	Y10   - BCD (lsb first) 10 Years
+ * 58 		P3    - Date Parity (even)
+ * 59		      - usually missing (minute indication), except for leap insertion
+ */
+
+/*-----------------------------------------------------------------------
+ * conversion table to map DCF77 bit stream into data fields.
+ * Encoding:
+ *   Each field of the DCF77 code is described with two adjacent entries in
+ *   this table. The first entry specifies the offset into the DCF77 data stream
+ *   while the length is given as the difference between the start index and
+ *   the start index of the following field.
+ */
+static struct rawdcfcode 
+{
+	char offset;			/* start bit */
+} rawdcfcode[] =
+{
+	{  0 }, { 15 }, { 16 }, { 17 }, { 19 }, { 20 }, { 21 }, { 25 }, { 28 }, { 29 },
+	{ 33 }, { 35 }, { 36 }, { 40 }, { 42 }, { 45 }, { 49 }, { 50 }, { 54 }, { 58 }, { 59 }
+};
+
+/*-----------------------------------------------------------------------
+ * symbolic names for the fields of DCF77 describes in "rawdcfcode".
+ * see comment above for the structure of the DCF77 data
+ */
+#define DCF_M	0
+#define DCF_R	1
+#define DCF_A1	2
+#define DCF_Z	3
+#define DCF_A2	4
+#define DCF_S	5
+#define DCF_M1	6
+#define DCF_M10	7
+#define DCF_P1	8
+#define DCF_H1	9
+#define DCF_H10	10
+#define DCF_P2	11
+#define DCF_D1	12
+#define DCF_D10	13
+#define DCF_DW	14
+#define DCF_MO	15
+#define DCF_MO0	16
+#define DCF_Y1	17
+#define DCF_Y10	18
+#define DCF_P3	19
+
+/*-----------------------------------------------------------------------
+ * parity field table (same encoding as rawdcfcode)
+ * This table describes the sections of the DCF77 code that are
+ * parity protected
+ */
+static struct partab
+{
+	char offset;			/* start bit of parity field */
+} partab[] =
+{
+	{ 21 }, { 29 }, { 36 }, { 59 }
+};
+
+/*-----------------------------------------------------------------------
+ * offsets for parity field descriptions
+ */
+#define DCF_P_P1	0
+#define DCF_P_P2	1
+#define DCF_P_P3	2
+
+/*-----------------------------------------------------------------------
+ * legal values for time zone information
+ */
+#define DCF_Z_MET 0x2
+#define DCF_Z_MED 0x1
+
+/*-----------------------------------------------------------------------
+ * symbolic representation if the DCF77 data stream
+ */
+static struct dcfparam
+{
+	unsigned char onebits[60];
+	unsigned char zerobits[60];
+} dcfparam = 
+{
+	"###############RADMLS1248124P124812P1248121241248112481248P", /* 'ONE' representation */
+	"--------------------s-------p------p----------------------p"  /* 'ZERO' representation */
+};
+
+/*-----------------------------------------------------------------------
+ * extract a bitfield from DCF77 datastream
+ * All numeric fields are LSB first.
+ * buf holds a pointer to a DCF77 data buffer in symbolic
+ *     representation
+ * idx holds the index to the field description in rawdcfcode
+ */
+static unsigned long
+ext_bf(
+	register unsigned char *buf,
+	register int   idx
+	)
+{
+	register unsigned long sum = 0;
+	register int i, first;
+
+	first = rawdcfcode[idx].offset;
+  
+	for (i = rawdcfcode[idx+1].offset - 1; i >= first; i--)
+	{
+		sum <<= 1;
+		sum |= (buf[i] != dcfparam.zerobits[i]);
+	}
+	return sum;
+}
+
+/*-----------------------------------------------------------------------
+ * check even parity integrity for a bitfield
+ *
+ * buf holds a pointer to a DCF77 data buffer in symbolic
+ *     representation
+ * idx holds the index to the field description in partab
+ */
+static unsigned
+pcheck(
+	register unsigned char *buf,
+	register int   idx
+	)
+{
+	register int i,last;
+	register unsigned psum = 1;
+
+	last = partab[idx+1].offset;
+
+	for (i = partab[idx].offset; i < last; i++)
+	    psum ^= (buf[i] != dcfparam.zerobits[i]);
+
+	return psum;
+}
+
+/*-----------------------------------------------------------------------
+ * convert a DCF77 data buffer into wall clock time + flags
+ *
+ * buffer holds a pointer to a DCF77 data buffer in symbolic
+ *        representation
+ * size   describes the length of DCF77 information in bits (represented
+ *        as chars in symbolic notation
+ * clock  points to a wall clock time description of the DCF77 data (result)
+ */
+static unsigned long
+convert_rawdcf(
+	       unsigned char   *buffer,
+	       int              size,
+	       clocktime_t     *clock_time
+	       )
+{
+	if (size < 57)
+	{
+		PRINTF("%-30s", "*** INCOMPLETE");
+		return CVT_NONE;
+	}
+  
+	/*
+	 * check Start and Parity bits
+	 */
+	if ((ext_bf(buffer, DCF_S) == 1) &&
+	    pcheck(buffer, DCF_P_P1) &&
+	    pcheck(buffer, DCF_P_P2) &&
+	    pcheck(buffer, DCF_P_P3))
+	{
+		/*
+		 * buffer OK - extract all fields and build wall clock time from them
+		 */
+
+		clock_time->flags  = 0;
+		clock_time->usecond= 0;
+		clock_time->second = 0;
+		clock_time->minute = ext_bf(buffer, DCF_M10);
+		clock_time->minute = TIMES10(clock_time->minute) + ext_bf(buffer, DCF_M1);
+		clock_time->hour   = ext_bf(buffer, DCF_H10);
+		clock_time->hour   = TIMES10(clock_time->hour)   + ext_bf(buffer, DCF_H1);
+		clock_time->day    = ext_bf(buffer, DCF_D10);
+		clock_time->day    = TIMES10(clock_time->day)    + ext_bf(buffer, DCF_D1);
+		clock_time->month  = ext_bf(buffer, DCF_MO0);
+		clock_time->month  = TIMES10(clock_time->month)  + ext_bf(buffer, DCF_MO);
+		clock_time->year   = ext_bf(buffer, DCF_Y10);
+		clock_time->year   = TIMES10(clock_time->year)   + ext_bf(buffer, DCF_Y1);
+		clock_time->wday   = ext_bf(buffer, DCF_DW);
+
+		/*
+		 * determine offset to UTC by examining the time zone
+		 */
+		switch (ext_bf(buffer, DCF_Z))
+		{
+		    case DCF_Z_MET:
+			clock_time->utcoffset = -60;
+			break;
+
+		    case DCF_Z_MED:
+			clock_time->flags     |= DCFB_DST;
+			clock_time->utcoffset  = -120;
+			break;
+
+		    default:
+			PRINTF("%-30s", "*** BAD TIME ZONE");
+			return CVT_FAIL|CVT_BADFMT;
+		}
+
+		/*
+		 * extract various warnings from DCF77
+		 */
+		if (ext_bf(buffer, DCF_A1))
+		    clock_time->flags |= DCFB_ANNOUNCE;
+
+		if (ext_bf(buffer, DCF_A2))
+		    clock_time->flags |= DCFB_LEAP;
+
+		if (ext_bf(buffer, DCF_R))
+		    clock_time->flags |= DCFB_ALTERNATE;
+
+		return CVT_OK;
+	}
+	else
+	{
+		/*
+		 * bad format - not for us
+		 */
+		PRINTF("%-30s", "*** BAD FORMAT (invalid/parity)");
+		return CVT_FAIL|CVT_BADFMT;
+	}
+}
+
+/*-----------------------------------------------------------------------
+ * raw dcf input routine - fix up 50 baud
+ * characters for 1/0 decision
+ */
+static unsigned long
+cvt_rawdcf(
+	   unsigned char   *buffer,
+	   int              size,
+	   clocktime_t     *clock_time
+	   )
+{
+	register unsigned char *s = buffer;
+	register unsigned char *e = buffer + size;
+	register unsigned char *b = dcfparam.onebits;
+	register unsigned char *c = dcfparam.zerobits;
+	register unsigned rtc = CVT_NONE;
+	register unsigned int i, lowmax, highmax, cutoff, span;
+#define BITS 9
+	unsigned char     histbuf[BITS];
+	/*
+	 * the input buffer contains characters with runs of consecutive
+	 * bits set. These set bits are an indication of the DCF77 pulse
+	 * length. We assume that we receive the pulse at 50 Baud. Thus
+	 * a 100ms pulse would generate a 4 bit train (20ms per bit and
+	 * start bit)
+	 * a 200ms pulse would create all zeroes (and probably a frame error)
+	 *
+	 * The basic idea is that on corret reception we must have two
+	 * maxima in the pulse length distribution histogram. (one for
+	 * the zero representing pulses and one for the one representing
+	 * pulses)
+	 * There will always be ones in the datastream, thus we have to see
+	 * two maxima.
+	 * The best point to cut for a 1/0 decision is the minimum between those
+	 * between the maxima. The following code tries to find this cutoff point.
+	 */
+
+	/*
+	 * clear histogram buffer
+	 */
+	for (i = 0; i < BITS; i++)
+	{
+		histbuf[i] = 0;
+	}
+
+	cutoff = 0;
+	lowmax = 0;
+
+	/*
+	 * convert sequences of set bits into bits counts updating
+	 * the histogram alongway
+	 */
+	while (s < e)
+	{
+		register unsigned int ch = *s ^ 0xFF;
+		/*
+		 * check integrity and update histogramm
+		 */
+		if (!((ch+1) & ch) || !*s)
+		{
+			/*
+			 * character ok
+			 */
+			for (i = 0; ch; i++)
+			{
+				ch >>= 1;
+			}
+
+			*s = i;
+			histbuf[i]++;
+			cutoff += i;
+			lowmax++;
+		}
+		else
+		{
+			/*
+			 * invalid character (no consecutive bit sequence)
+			 */
+			dprintf(("parse: cvt_rawdcf: character check for 0x%x@%d FAILED\n", *s, s - buffer));
+			*s = (unsigned char)~0;
+			rtc = CVT_FAIL|CVT_BADFMT;
+		}
+		s++;
+	}
+
+	/*
+	 * first cutoff estimate (average bit count - must be between both
+	 * maxima)
+	 */
+	if (lowmax)
+	{
+		cutoff /= lowmax;
+	}
+	else
+	{
+		cutoff = 4;	/* doesn't really matter - it'll fail anyway, but gives error output */
+	}
+
+	dprintf(("parse: cvt_rawdcf: average bit count: %d\n", cutoff));
+
+	lowmax = 0;  /* weighted sum */
+	highmax = 0; /* bitcount */
+
+	/*
+	 * collect weighted sum of lower bits (left of initial guess)
+	 */
+	dprintf(("parse: cvt_rawdcf: histogram:"));
+	for (i = 0; i <= cutoff; i++)
+	{
+		lowmax  += histbuf[i] * i;
+		highmax += histbuf[i];
+		dprintf((" %d", histbuf[i]));
+	}
+	dprintf((" <M>"));
+
+	/*
+	 * round up
+	 */
+	lowmax += highmax / 2;
+
+	/*
+	 * calculate lower bit maximum (weighted sum / bit count)
+	 *
+	 * avoid divide by zero
+	 */
+	if (highmax)
+	{
+		lowmax /= highmax;
+	}
+	else
+	{
+		lowmax = 0;
+	}
+
+	highmax = 0; /* weighted sum of upper bits counts */
+	cutoff = 0;  /* bitcount */
+
+	/*
+	 * collect weighted sum of lower bits (right of initial guess)
+	 */
+	for (; i < BITS; i++)
+	{
+		highmax+=histbuf[i] * i;
+		cutoff +=histbuf[i];
+		dprintf((" %d", histbuf[i]));
+	}
+	dprintf(("\n"));
+
+	/*
+	 * determine upper maximum (weighted sum / bit count)
+	 */
+	if (cutoff)
+	{
+		highmax /= cutoff;
+	}
+	else
+	{
+		highmax = BITS-1;
+	}
+
+	/*
+	 * following now holds:
+	 * lowmax <= cutoff(initial guess) <= highmax
+	 * best cutoff is the minimum nearest to higher bits
+	 */
+
+	/*
+	 * find the minimum between lowmax and highmax (detecting
+	 * possibly a minimum span)
+	 */
+	span = cutoff = lowmax;
+	for (i = lowmax; i <= highmax; i++)
+	{
+		if (histbuf[cutoff] > histbuf[i])
+		{
+			/*
+			 * got a new minimum move beginning of minimum (cutoff) and
+			 * end of minimum (span) there
+			 */
+			cutoff = span = i;
+		}
+		else
+		    if (histbuf[cutoff] == histbuf[i])
+		    {
+			    /*
+			     * minimum not better yet - but it spans more than
+			     * one bit value - follow it
+			     */
+			    span = i;
+		    }
+	}
+
+	/*
+	 * cutoff point for 1/0 decision is the middle of the minimum section
+	 * in the histogram
+	 */
+	cutoff = (cutoff + span) / 2;
+
+	dprintf(("parse: cvt_rawdcf: lower maximum %d, higher maximum %d, cutoff %d\n", lowmax, highmax, cutoff));
+
+	/*
+	 * convert the bit counts to symbolic 1/0 information for data conversion
+	 */
+	s = buffer;
+	while ((s < e) && *c && *b)
+	{
+		if (*s == (unsigned char)~0)
+		{
+			/*
+			 * invalid character
+			 */
+			*s = '?';
+		}
+		else
+		{
+			/*
+			 * symbolic 1/0 representation
+			 */
+			*s = (*s >= cutoff) ? *b : *c;
+		}
+		s++;
+		b++;
+		c++;
+	}
+
+	/*
+	 * if everything went well so far return the result of the symbolic
+	 * conversion routine else just the accumulated errors
+	 */
+	if (rtc != CVT_NONE) 
+	{
+		PRINTF("%-30s", "*** BAD DATA");
+	}
+
+	return (rtc == CVT_NONE) ? convert_rawdcf(buffer, size, clock_time) : rtc;
+}
+
+/*-----------------------------------------------------------------------
+ * convert a wall clock time description of DCF77 to a Unix time (seconds
+ * since 1.1. 1970 UTC)
+ */
+time_t
+dcf_to_unixtime(
+		clocktime_t   *clock_time,
+		unsigned *cvtrtc
+		)
+{
+#define SETRTC(_X_)	{ if (cvtrtc) *cvtrtc = (_X_); }
+	static int days_of_month[] = 
+	{
+		0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
+	};
+	register int i;
+	time_t t;
+  
+	/*
+	 * map 2 digit years to 19xx (DCF77 is a 20th century item)
+	 */
+	if ( clock_time->year < YEAR_PIVOT ) 	/* in case of	   Y2KFixes [ */
+		clock_time->year += 100;	/* *year%100, make tm_year */
+						/* *(do we need this?) */
+	if ( clock_time->year < YEAR_BREAK )	/* (failsafe if) */
+	    clock_time->year += 1900;				/* Y2KFixes ] */
+
+	/*
+	 * must have been a really bad year code - drop it
+	 */
+	if (clock_time->year < (YEAR_PIVOT + 1900) )		/* Y2KFixes */
+	{
+		SETRTC(CVT_FAIL|CVT_BADDATE);
+		return -1;
+	}
+	/*
+	 * sorry, slow section here - but it's not time critical anyway
+	 */
+
+	/*
+	 * calculate days since 1970 (watching leap years)
+	 */
+	t = julian0( clock_time->year ) - julian0( 1970 );
+
+  				/* month */
+	if (clock_time->month <= 0 || clock_time->month > 12)
+	{
+		SETRTC(CVT_FAIL|CVT_BADDATE);
+		return -1;		/* bad month */
+	}
+				/* adjust current leap year */
+#if 0
+	if (clock_time->month < 3 && days_per_year(clock_time->year) == 366)
+	    t--;
+#endif
+
+	/*
+	 * collect days from months excluding the current one
+	 */
+	for (i = 1; i < clock_time->month; i++)
+	{
+		t += days_of_month[i];
+	}
+				/* day */
+	if (clock_time->day < 1 || ((clock_time->month == 2 && days_per_year(clock_time->year) == 366) ?
+			       clock_time->day > 29 : clock_time->day > days_of_month[clock_time->month]))
+	{
+		SETRTC(CVT_FAIL|CVT_BADDATE);
+		return -1;		/* bad day */
+	}
+
+	/*
+	 * collect days from date excluding the current one
+	 */
+	t += clock_time->day - 1;
+
+				/* hour */
+	if (clock_time->hour < 0 || clock_time->hour >= 24)
+	{
+		SETRTC(CVT_FAIL|CVT_BADTIME);
+		return -1;		/* bad hour */
+	}
+
+	/*
+	 * calculate hours from 1. 1. 1970
+	 */
+	t = TIMES24(t) + clock_time->hour;
+
+  				/* min */
+	if (clock_time->minute < 0 || clock_time->minute > 59)
+	{
+		SETRTC(CVT_FAIL|CVT_BADTIME);
+		return -1;		/* bad min */
+	}
+
+	/*
+	 * calculate minutes from 1. 1. 1970
+	 */
+	t = TIMES60(t) + clock_time->minute;
+				/* sec */
+  
+	/*
+	 * calculate UTC in minutes
+	 */
+	t += clock_time->utcoffset;
+
+	if (clock_time->second < 0 || clock_time->second > 60)	/* allow for LEAPs */
+	{
+		SETRTC(CVT_FAIL|CVT_BADTIME);
+		return -1;		/* bad sec */
+	}
+
+	/*
+	 * calculate UTC in seconds - phew !
+	 */
+	t  = TIMES60(t) + clock_time->second;
+				/* done */
+	return t;
+}
+
+/*-----------------------------------------------------------------------
+ * cheap half baked 1/0 decision - for interactive operation only
+ */
+static char
+type(
+     unsigned int c
+     )
+{
+	c ^= 0xFF;
+	return (c > 0xF);
+}
+
+/*-----------------------------------------------------------------------
+ * week day representation
+ */
+static const char *wday[8] =
+{
+	"??",
+	"Mo",
+	"Tu",
+	"We",
+	"Th",
+	"Fr",
+	"Sa",
+	"Su"
+};
+
+/*-----------------------------------------------------------------------
+ * generate a string representation for a timeval
+ */
+static char *
+pr_timeval(
+	   struct timeval *val
+	   )
+{
+	static char buf[20];
+
+	if (val->tv_sec == 0)
+	    sprintf(buf, "%c0.%06ld", (val->tv_usec < 0) ? '-' : '+', (long int)l_abs(val->tv_usec));
+	else
+	    sprintf(buf, "%ld.%06ld", (long int)val->tv_sec, (long int)l_abs(val->tv_usec));
+	return buf;
+}
+
+/*-----------------------------------------------------------------------
+ * correct the current time by an offset by setting the time rigorously
+ */
+static void
+set_time(
+	 struct timeval *offset
+	 )
+{
+	struct timeval the_time;
+
+	if (no_set)
+	    return;
+
+	LPRINTF("set_time: %s ", pr_timeval(offset));
+	syslog(LOG_NOTICE, "setting time (offset %s)", pr_timeval(offset));
+
+	if (gettimeofday(&the_time, 0L) == -1)
+	{
+		perror("gettimeofday()");
+	}
+	else
+	{
+		timeradd(&the_time, offset);
+		if (settimeofday(&the_time, 0L) == -1)
+		{
+			perror("settimeofday()");
+		}
+	}
+}
+
+/*-----------------------------------------------------------------------
+ * slew the time by a given offset
+ */
+static void
+adj_time(
+	 long offset
+	 )
+{
+	struct timeval time_offset;
+
+	if (no_set)
+	    return;
+
+	time_offset.tv_sec  = offset / 1000000;
+	time_offset.tv_usec = offset % 1000000;
+
+	LPRINTF("adj_time: %ld us ", (long int)offset);
+	if (adjtime(&time_offset, 0L) == -1)
+	    perror("adjtime()");
+}
+
+/*-----------------------------------------------------------------------
+ * read in a possibly previously written drift value
+ */
+static void
+read_drift(
+	   const char *drift_file
+	   )
+{
+	FILE *df;
+
+	df = fopen(drift_file, "r");
+	if (df != NULL)
+	{
+		int idrift = 0, fdrift = 0;
+
+		fscanf(df, "%4d.%03d", &idrift, &fdrift);
+		fclose(df);
+		LPRINTF("read_drift: %d.%03d ppm ", idrift, fdrift);
+
+		accum_drift = idrift << USECSCALE;
+		fdrift     = (fdrift << USECSCALE) / 1000;
+		accum_drift += fdrift & (1<<USECSCALE);
+		LPRINTF("read_drift: drift_comp %ld ", (long int)accum_drift);
+	}
+}
+
+/*-----------------------------------------------------------------------
+ * write out the current drift value
+ */
+static void
+update_drift(
+	     const char *drift_file,
+	     long offset,
+	     time_t reftime
+	     )
+{
+	FILE *df;
+
+	df = fopen(drift_file, "w");
+	if (df != NULL)
+	{
+		int idrift = R_SHIFT(accum_drift, USECSCALE);
+		int fdrift = accum_drift & ((1<<USECSCALE)-1);
+
+		LPRINTF("update_drift: drift_comp %ld ", (long int)accum_drift);
+		fdrift = (fdrift * 1000) / (1<<USECSCALE);
+		fprintf(df, "%4d.%03d %c%ld.%06ld %.24s\n", idrift, fdrift,
+			(offset < 0) ? '-' : '+', (long int)(l_abs(offset) / 1000000),
+			(long int)(l_abs(offset) % 1000000), asctime(localtime(&reftime)));
+		fclose(df);
+		LPRINTF("update_drift: %d.%03d ppm ", idrift, fdrift);
+	}
+}
+
+/*-----------------------------------------------------------------------
+ * process adjustments derived from the DCF77 observation
+ * (controls clock PLL)
+ */
+static void
+adjust_clock(
+	     struct timeval *offset,
+	     const char *drift_file,
+	     time_t reftime
+	     )
+{
+	struct timeval toffset;
+	register long usecoffset;
+	int tmp;
+
+	if (no_set)
+	    return;
+
+	if (skip_adjust)
+	{
+		skip_adjust = 0;
+		return;
+	}
+
+	toffset = *offset;
+	toffset.tv_sec  = l_abs(toffset.tv_sec);
+	toffset.tv_usec = l_abs(toffset.tv_usec);
+	if (timercmp(&toffset, &max_adj_offset, >))
+	{
+		/*
+		 * hopeless - set the clock - and clear the timing
+		 */
+		set_time(offset);
+		clock_adjust = 0;
+		skip_adjust  = 1;
+		return;
+	}
+
+	usecoffset   = offset->tv_sec * 1000000 + offset->tv_usec;
+
+	clock_adjust = R_SHIFT(usecoffset, TIMECONSTANT);	/* adjustment to make for next period */
+
+	tmp = 0;
+	while (adjustments > (1 << tmp))
+	    tmp++;
+	adjustments = 0;
+	if (tmp > FREQ_WEIGHT)
+	    tmp = FREQ_WEIGHT;
+
+	accum_drift  += R_SHIFT(usecoffset << USECSCALE, TIMECONSTANT+TIMECONSTANT+FREQ_WEIGHT-tmp);
+
+	if (accum_drift > MAX_DRIFT)		/* clamp into interval */
+	    accum_drift = MAX_DRIFT;
+	else
+	    if (accum_drift < -MAX_DRIFT)
+		accum_drift = -MAX_DRIFT;
+
+	update_drift(drift_file, usecoffset, reftime);
+	LPRINTF("clock_adjust: %s, clock_adjust %ld, drift_comp %ld(%ld) ",
+		pr_timeval(offset),(long int) R_SHIFT(clock_adjust, USECSCALE),
+		(long int)R_SHIFT(accum_drift, USECSCALE), (long int)accum_drift);
+}
+
+/*-----------------------------------------------------------------------
+ * adjust the clock by a small mount to simulate frequency correction
+ */
+static void
+periodic_adjust(
+		void
+		)
+{
+	register long adjustment;
+
+	adjustments++;
+
+	adjustment = R_SHIFT(clock_adjust, PHASE_WEIGHT);
+
+	clock_adjust -= adjustment;
+
+	adjustment += R_SHIFT(accum_drift, USECSCALE+ADJINTERVAL);
+
+	adj_time(adjustment);
+}
+
+/*-----------------------------------------------------------------------
+ * control synchronisation status (warnings) and do periodic adjusts
+ * (frequency control simulation)
+ */
+static void
+tick(
+     void
+     )
+{
+	static unsigned long last_notice = 0;
+
+#if !defined(HAVE_SIGACTION) && !defined(HAVE_SIGVEC)
+	(void)signal(SIGALRM, tick);
+#endif
+
+	periodic_adjust();
+
+	ticks += 1<<ADJINTERVAL;
+
+	if ((ticks - last_sync) > MAX_UNSYNC)
+	{
+		/*
+		 * not getting time for a while
+		 */
+		if (sync_state == SYNC)
+		{
+			/*
+			 * completely lost information
+			 */
+			sync_state = NO_SYNC;
+			syslog(LOG_INFO, "DCF77 reception lost (timeout)");
+			last_notice = ticks;
+		}
+		else
+		    /*
+		     * in NO_SYNC state - look whether its time to speak up again
+		     */
+		    if ((ticks - last_notice) > NOTICE_INTERVAL)
+		    {
+			    syslog(LOG_NOTICE, "still not synchronized to DCF77 - check receiver/signal");
+			    last_notice = ticks;
+		    }
+	}
+
+#ifndef ITIMER_REAL
+	(void) alarm(1<<ADJINTERVAL);
+#endif
+}
+
+/*-----------------------------------------------------------------------
+ * break association from terminal to avoid catching terminal
+ * or process group related signals (-> daemon operation)
+ */
+static void
+detach(
+       void
+       )
+{
+#   ifdef HAVE_DAEMON
+	daemon(0, 0);
+#   else /* not HAVE_DAEMON */
+	if (fork())
+	    exit(0);
+
+	{
+		u_long s;
+		int max_fd;
+
+#if defined(HAVE_SYSCONF) && defined(_SC_OPEN_MAX)
+		max_fd = sysconf(_SC_OPEN_MAX);
+#else /* HAVE_SYSCONF && _SC_OPEN_MAX */
+		max_fd = getdtablesize();
+#endif /* HAVE_SYSCONF && _SC_OPEN_MAX */
+		for (s = 0; s < max_fd; s++)
+		    (void) close((int)s);
+		(void) open("/", 0);
+		(void) dup2(0, 1);
+		(void) dup2(0, 2);
+#ifdef SYS_DOMAINOS
+		{
+			uid_$t puid;
+			status_$t st;
+
+			proc2_$who_am_i(&puid);
+			proc2_$make_server(&puid, &st);
+		}
+#endif /* SYS_DOMAINOS */
+#if defined(HAVE_SETPGID) || defined(HAVE_SETSID)
+# ifdef HAVE_SETSID
+		if (setsid() == (pid_t)-1)
+		    syslog(LOG_ERR, "dcfd: setsid(): %m");
+# else
+		if (setpgid(0, 0) == -1)
+		    syslog(LOG_ERR, "dcfd: setpgid(): %m");
+# endif
+#else /* HAVE_SETPGID || HAVE_SETSID */
+		{
+			int fid;
+
+			fid = open("/dev/tty", 2);
+			if (fid >= 0)
+			{
+				(void) ioctl(fid, (u_long) TIOCNOTTY, (char *) 0);
+				(void) close(fid);
+			}
+# ifdef HAVE_SETPGRP_0
+			(void) setpgrp();
+# else /* HAVE_SETPGRP_0 */
+			(void) setpgrp(0, getpid());
+# endif /* HAVE_SETPGRP_0 */
+		}
+#endif /* HAVE_SETPGID || HAVE_SETSID */
+	}
+#endif /* not HAVE_DAEMON */
+}
+
+/*-----------------------------------------------------------------------
+ * list possible arguments and options
+ */
+static void
+usage(
+      char *program
+      )
+{
+  fprintf(stderr, "usage: %s [-n] [-f] [-l] [-t] [-i] [-o] [-d <drift_file>] [-D <input delay>] <device>\n", program);
+	fprintf(stderr, "\t-n              do not change time\n");
+	fprintf(stderr, "\t-i              interactive\n");
+	fprintf(stderr, "\t-t              trace (print all datagrams)\n");
+	fprintf(stderr, "\t-f              print all databits (includes PTB private data)\n");
+	fprintf(stderr, "\t-l              print loop filter debug information\n");
+	fprintf(stderr, "\t-o              print offet average for current minute\n");
+	fprintf(stderr, "\t-Y              make internal Y2K checks then exit\n");	/* Y2KFixes */
+	fprintf(stderr, "\t-d <drift_file> specify alternate drift file\n");
+	fprintf(stderr, "\t-D <input delay>specify delay from input edge to processing in micro seconds\n");
+}
+
+/*-----------------------------------------------------------------------
+ * check_y2k() - internal check of Y2K logic
+ *	(a lot of this logic lifted from ../ntpd/check_y2k.c)
+ */
+int
+check_y2k( void )
+{ 
+    int  year;			/* current working year */
+    int  year0 = 1900;		/* sarting year for NTP time */
+    int  yearend;		/* ending year we test for NTP time.
+				    * 32-bit systems: through 2036, the
+				      **year in which NTP time overflows.
+				    * 64-bit systems: a reasonable upper
+				      **limit (well, maybe somewhat beyond
+				      **reasonable, but well before the
+				      **max time, by which time the earth
+				      **will be dead.) */
+    time_t Time;
+    struct tm LocalTime;
+
+    int Fatals, Warnings;
+#define Error(year) if ( (year)>=2036 && LocalTime.tm_year < 110 ) \
+	Warnings++; else Fatals++
+
+    Fatals = Warnings = 0;
+
+    Time = time( (time_t *)NULL );
+    LocalTime = *localtime( &Time );
+
+    year = ( sizeof( u_long ) > 4 ) 	/* save max span using year as temp */
+		? ( 400 * 3 ) 		/* three greater gregorian cycles */
+		: ((int)(0x7FFFFFFF / 365.242 / 24/60/60)* 2 ); /*32-bit limit*/
+			/* NOTE: will automacially expand test years on
+			 * 64 bit machines.... this may cause some of the
+			 * existing ntp logic to fail for years beyond
+			 * 2036 (the current 32-bit limit). If all checks
+			 * fail ONLY beyond year 2036 you may ignore such
+			 * errors, at least for a decade or so. */
+    yearend = year0 + year;
+
+    year = 1900+YEAR_PIVOT;
+    printf( "  starting year %04d\n", (int) year );
+    printf( "  ending year   %04d\n", (int) yearend );
+
+    for ( ; year < yearend; year++ )
+    {
+	clocktime_t  ct;
+	time_t	     Observed;
+	time_t	     Expected;
+	unsigned     Flag;
+	unsigned long t;
+
+	ct.day = 1;
+	ct.month = 1;
+	ct.year = year;
+	ct.hour = ct.minute = ct.second = ct.usecond = 0;
+	ct.utcoffset = 0;
+	ct.flags = 0;
+
+	Flag = 0;
+ 	Observed = dcf_to_unixtime( &ct, &Flag );
+		/* seems to be a clone of parse_to_unixtime() with
+		 * *a minor difference to arg2 type */
+	if ( ct.year != year )
+	{
+	    fprintf( stdout, 
+	       "%04d: dcf_to_unixtime(,%d) CORRUPTED ct.year: was %d\n",
+	       (int)year, (int)Flag, (int)ct.year );
+	    Error(year);
+	    break;
+	}
+	t = julian0(year) - julian0(1970);	/* Julian day from 1970 */
+	Expected = t * 24 * 60 * 60;
+	if ( Observed != Expected  ||  Flag )
+	{   /* time difference */
+	    fprintf( stdout, 
+	       "%04d: dcf_to_unixtime(,%d) FAILURE: was=%lu s/b=%lu  (%ld)\n",
+	       year, (int)Flag, 
+	       (unsigned long)Observed, (unsigned long)Expected,
+	       ((long)Observed - (long)Expected) );
+	    Error(year);
+	    break;
+	}
+
+	if ( year >= YEAR_PIVOT+1900 )
+	{
+	    /* check year % 100 code we put into dcf_to_unixtime() */
+	    ct.year = year % 100;
+	    Flag = 0;
+
+	    Observed = dcf_to_unixtime( &ct, &Flag );
+
+	    if ( Observed != Expected  ||  Flag )
+	    {   /* time difference */
+		fprintf( stdout, 
+"%04d: dcf_to_unixtime(%d,%d) FAILURE: was=%lu s/b=%lu  (%ld)\n",
+		   year, (int)ct.year, (int)Flag, 
+		   (unsigned long)Observed, (unsigned long)Expected,
+		   ((long)Observed - (long)Expected) );
+		Error(year);
+		break;
+	    }
+
+	    /* check year - 1900 code we put into dcf_to_unixtime() */
+	    ct.year = year - 1900;
+	    Flag = 0;
+
+	    Observed = dcf_to_unixtime( &ct, &Flag );
+
+	    if ( Observed != Expected  ||  Flag ) {   /* time difference */
+		    fprintf( stdout, 
+			     "%04d: dcf_to_unixtime(%d,%d) FAILURE: was=%lu s/b=%lu  (%ld)\n",
+			     year, (int)ct.year, (int)Flag, 
+			     (unsigned long)Observed, (unsigned long)Expected,
+			     ((long)Observed - (long)Expected) );
+		    Error(year);
+		break;
+	    }
+
+
+	}
+    }
+
+    return ( Fatals );
+}
+
+/*--------------------------------------------------
+ * rawdcf_init - set up modem lines for RAWDCF receivers
+ */
+#if defined(TIOCMSET) && (defined(TIOCM_DTR) || defined(CIOCM_DTR))
+static void
+rawdcf_init(
+	int fd
+	)
+{
+	/*
+	 * You can use the RS232 to supply the power for a DCF77 receiver.
+	 * Here a voltage between the DTR and the RTS line is used. Unfortunately
+	 * the name has changed from CIOCM_DTR to TIOCM_DTR recently.
+	 */
+	
+#ifdef TIOCM_DTR
+	int sl232 = TIOCM_DTR;	/* turn on DTR for power supply */
+#else
+	int sl232 = CIOCM_DTR;	/* turn on DTR for power supply */
+#endif
+
+	if (ioctl(fd, TIOCMSET, (caddr_t)&sl232) == -1)
+	{
+		syslog(LOG_NOTICE, "rawdcf_init: WARNING: ioctl(fd, TIOCMSET, [C|T]IOCM_DTR): %m");
+	}
+}
+#else
+static void
+rawdcf_init(
+	    int fd
+	)
+{
+	syslog(LOG_NOTICE, "rawdcf_init: WARNING: OS interface incapable of setting DTR to power DCF modules");
+}
+#endif  /* DTR initialisation type */
+
+/*-----------------------------------------------------------------------
+ * main loop - argument interpreter / setup / main loop
+ */
+int
+main(
+     int argc,
+     char **argv
+     )
+{
+	unsigned char c;
+	char **a = argv;
+	int  ac = argc;
+	char *file = NULL;
+	const char *drift_file = "/etc/dcfd.drift";
+	int fd;
+	int offset = 15;
+	int offsets = 0;
+	int delay = DEFAULT_DELAY;	/* average delay from input edge to time stamping */
+	int trace = 0;
+	int errs = 0;
+
+	/*
+	 * process arguments
+	 */
+	while (--ac)
+	{
+		char *arg = *++a;
+		if (*arg == '-')
+		    while ((c = *++arg))
+			switch (c)
+			{
+			    case 't':
+				trace = 1;
+				interactive = 1;
+				break;
+
+			    case 'f':
+				offset = 0;
+				interactive = 1;
+				break;
+
+			    case 'l':
+				loop_filter_debug = 1;
+				offsets = 1;
+				interactive = 1;
+				break;
+
+			    case 'n':
+				no_set = 1;
+				break;
+
+			    case 'o':
+				offsets = 1;
+				interactive = 1;
+				break;
+
+			    case 'i':
+				interactive = 1;
+				break;
+
+			    case 'D':
+				if (ac > 1)
+				{
+					delay = atoi(*++a);
+					ac--;
+				}
+				else
+				{
+					fprintf(stderr, "%s: -D requires integer argument\n", argv[0]);
+					errs=1;
+				}
+				break;
+	      
+			    case 'd':
+				if (ac > 1)
+				{
+					drift_file = *++a;
+					ac--;
+				}
+				else
+				{
+					fprintf(stderr, "%s: -d requires file name argument\n", argv[0]);
+					errs=1;
+				}
+				break;
+	      
+			    case 'Y':	
+				errs=check_y2k();
+				exit( errs ? 1 : 0 );
+
+			    default:
+				fprintf(stderr, "%s: unknown option -%c\n", argv[0], c);
+				errs=1;
+				break;
+			}
+		else
+		    if (file == NULL)
+			file = arg;
+		    else
+		    {
+			    fprintf(stderr, "%s: device specified twice\n", argv[0]);
+			    errs=1;
+		    }
+	}
+
+	if (errs)
+	{
+		usage(argv[0]);
+		exit(1);
+	}
+	else
+	    if (file == NULL)
+	    {
+		    fprintf(stderr, "%s: device not specified\n", argv[0]);
+		    usage(argv[0]);
+		    exit(1);
+	    }
+
+	errs = LINES+1;
+
+	/*
+	 * get access to DCF77 tty port
+	 */
+	fd = open(file, O_RDONLY);
+	if (fd == -1)
+	{
+		perror(file);
+		exit(1);
+	}
+	else
+	{
+		int i, rrc;
+		struct timeval t, tt, tlast;
+		struct timeval timeout;
+		struct timeval phase;
+		struct timeval time_offset;
+		char pbuf[61];		/* printable version */
+		char buf[61];		/* raw data */
+		clocktime_t clock_time;	/* wall clock time */
+		time_t utc_time = 0;
+		time_t last_utc_time = 0;
+		long usecerror = 0;
+		long lasterror = 0;
+#if defined(HAVE_TERMIOS_H) || defined(STREAM)
+		struct termios term;
+#else  /* not HAVE_TERMIOS_H || STREAM */
+# if defined(HAVE_TERMIO_H) || defined(HAVE_SYSV_TTYS)
+		struct termio term;
+# endif/* HAVE_TERMIO_H || HAVE_SYSV_TTYS */
+#endif /* not HAVE_TERMIOS_H || STREAM */
+		unsigned int rtc = CVT_NONE;
+
+		rawdcf_init(fd);
+		
+		timeout.tv_sec  = 1;
+		timeout.tv_usec = 500000;
+
+		phase.tv_sec    = 0;
+		phase.tv_usec   = delay;
+
+		/*
+		 * setup TTY (50 Baud, Read, 8Bit, No Hangup, 1 character IO)
+		 */
+		if (TTY_GETATTR(fd,  &term) == -1)
+		{
+			perror("tcgetattr");
+			exit(1);
+		}
+
+		memset(term.c_cc, 0, sizeof(term.c_cc));
+		term.c_cc[VMIN] = 1;
+#ifdef NO_PARENB_IGNPAR
+		term.c_cflag = B50|CS8|CREAD|CLOCAL;
+#else
+		term.c_cflag = B50|CS8|CREAD|CLOCAL|PARENB;
+#endif
+		term.c_iflag = IGNPAR;
+		term.c_oflag = 0;
+		term.c_lflag = 0;
+
+		if (TTY_SETATTR(fd, &term) == -1)
+		{
+			perror("tcsetattr");
+			exit(1);
+		}
+
+		/*
+		 * loose terminal if in daemon operation
+		 */
+		if (!interactive)
+		    detach();
+      
+		/*
+		 * get syslog() initialized
+		 */
+#ifdef LOG_DAEMON
+		openlog("dcfd", LOG_PID, LOG_DAEMON);
+#else
+		openlog("dcfd", LOG_PID);
+#endif
+
+		/*
+		 * setup periodic operations (state control / frequency control)
+		 */
+#ifdef HAVE_SIGVEC
+		{
+			struct sigvec vec;
+
+			vec.sv_handler   = tick;
+			vec.sv_mask      = 0;
+			vec.sv_flags     = 0;
+
+			if (sigvec(SIGALRM, &vec, (struct sigvec *)0) == -1)
+			{
+				syslog(LOG_ERR, "sigvec(SIGALRM): %m");
+				exit(1);
+			}
+		}
+#else
+#ifdef HAVE_SIGACTION
+		{
+			struct sigaction act;
+
+			act.sa_handler   = tick;
+# ifdef HAVE_SA_SIGACTION_IN_STRUCT_SIGACTION
+			act.sa_sigaction = (void (*) P((int, siginfo_t *, void *)))0;
+# endif /* HAVE_SA_SIGACTION_IN_STRUCT_SIGACTION */
+			sigemptyset(&act.sa_mask);
+			act.sa_flags     = 0;
+
+			if (sigaction(SIGALRM, &act, (struct sigaction *)0) == -1)
+			{
+				syslog(LOG_ERR, "sigaction(SIGALRM): %m");
+				exit(1);
+			}
+		}
+#else
+		(void) signal(SIGALRM, tick);
+#endif
+#endif
+
+#ifdef ITIMER_REAL
+		{
+			struct itimerval it;
+
+			it.it_interval.tv_sec  = 1<<ADJINTERVAL;
+			it.it_interval.tv_usec = 0;
+			it.it_value.tv_sec     = 1<<ADJINTERVAL;
+			it.it_value.tv_usec    = 0;
+	
+			if (setitimer(ITIMER_REAL, &it, (struct itimerval *)0) == -1)
+			{
+				syslog(LOG_ERR, "setitimer: %m");
+				exit(1);
+			}
+		}
+#else
+		(void) alarm(1<<ADJINTERVAL);
+#endif
+
+		PRINTF("  DCF77 monitor - Copyright (C) 1993-1998 by Frank Kardel\n\n");
+
+		pbuf[60] = '\0';
+		for ( i = 0; i < 60; i++)
+		    pbuf[i] = '.';
+
+		read_drift(drift_file);
+
+		/*
+		 * what time is it now (for interval measurement)
+		 */
+		gettimeofday(&tlast, 0L);
+		i = 0;
+		/*
+		 * loop until input trouble ...
+		 */
+		do
+		{
+			/*
+			 * get an impulse
+			 */
+			while ((rrc = read(fd, &c, 1)) == 1)
+			{
+				gettimeofday(&t, 0L);
+				tt = t;
+				timersub(&t, &tlast);
+
+				if (errs > LINES)
+				{
+					PRINTF("  %s", &"PTB private....RADMLSMin....PHour..PMDay..DayMonthYear....P\n"[offset]);
+					PRINTF("  %s", &"---------------RADMLS1248124P124812P1248121241248112481248P\n"[offset]);
+					errs = 0;
+				}
+
+				/*
+				 * timeout -> possible minute mark -> interpretation
+				 */
+				if (timercmp(&t, &timeout, >))
+				{
+					PRINTF("%c %.*s ", pat[i % (sizeof(pat)-1)], 59 - offset, &pbuf[offset]);
+
+					if ((rtc = cvt_rawdcf((unsigned char *)buf, i, &clock_time)) != CVT_OK)
+					{
+						/*
+						 * this data was bad - well - forget synchronisation for now
+						 */
+						PRINTF("\n");
+						if (sync_state == SYNC)
+						{
+							sync_state = NO_SYNC;
+							syslog(LOG_INFO, "DCF77 reception lost (bad data)");
+						}
+						errs++;
+					}
+					else
+					    if (trace)
+					    {
+						    PRINTF("\r  %.*s ", 59 - offset, &buf[offset]);
+					    }
+
+
+					buf[0] = c;
+
+					/*
+					 * collect first character
+					 */
+					if (((c^0xFF)+1) & (c^0xFF))
+					    pbuf[0] = '?';
+					else
+					    pbuf[0] = type(c) ? '#' : '-';
+
+					for ( i = 1; i < 60; i++)
+					    pbuf[i] = '.';
+
+					i = 0;
+				}
+				else
+				{
+					/*
+					 * collect character
+					 */
+					buf[i] = c;
+
+					/*
+					 * initial guess (usually correct)
+					 */
+					if (((c^0xFF)+1) & (c^0xFF))
+					    pbuf[i] = '?';
+					else
+					    pbuf[i] = type(c) ? '#' : '-';
+
+					PRINTF("%c %.*s ", pat[i % (sizeof(pat)-1)], 59 - offset, &pbuf[offset]);
+				}
+
+				if (i == 0 && rtc == CVT_OK)
+				{
+					/*
+					 * we got a good time code here - try to convert it to
+					 * UTC
+					 */
+					if ((utc_time = dcf_to_unixtime(&clock_time, &rtc)) == -1)
+					{
+						PRINTF("*** BAD CONVERSION\n");
+					}
+
+					if (utc_time != (last_utc_time + 60))
+					{
+						/*
+						 * well, two successive sucessful telegrams are not 60 seconds
+						 * apart
+						 */
+						PRINTF("*** NO MINUTE INC\n");
+						if (sync_state == SYNC)
+						{
+							sync_state = NO_SYNC;
+							syslog(LOG_INFO, "DCF77 reception lost (data mismatch)");
+						}
+						errs++;
+						rtc = CVT_FAIL|CVT_BADTIME|CVT_BADDATE;
+					}
+					else
+					    usecerror = 0;
+
+					last_utc_time = utc_time;
+				}
+
+				if (rtc == CVT_OK)
+				{
+					if (i == 0)
+					{
+						/*
+						 * valid time code - determine offset and
+						 * note regained reception
+						 */
+						last_sync = ticks;
+						if (sync_state == NO_SYNC)
+						{
+							syslog(LOG_INFO, "receiving DCF77");
+						}
+						else
+						{
+							/*
+							 * we had at least one minute SYNC - thus
+							 * last error is valid
+							 */
+							time_offset.tv_sec  = lasterror / 1000000;
+							time_offset.tv_usec = lasterror % 1000000;
+							adjust_clock(&time_offset, drift_file, utc_time);
+						}
+						sync_state = SYNC;
+					}
+
+					time_offset.tv_sec  = utc_time + i;
+					time_offset.tv_usec = 0;
+
+					timeradd(&time_offset, &phase);
+
+					usecerror += (time_offset.tv_sec - tt.tv_sec) * 1000000 + time_offset.tv_usec
+						-tt.tv_usec;
+
+					/*
+					 * output interpreted DCF77 data
+					 */
+					PRINTF(offsets ? "%s, %2d:%02d:%02d, %d.%02d.%02d, <%s%s%s%s> (%c%d.%06ds)" :
+					       "%s, %2d:%02d:%02d, %d.%02d.%02d, <%s%s%s%s>",
+					       wday[clock_time.wday],
+					       clock_time.hour, clock_time.minute, i, clock_time.day, clock_time.month,
+					       clock_time.year,
+					       (clock_time.flags & DCFB_ALTERNATE) ? "R" : "_",
+					       (clock_time.flags & DCFB_ANNOUNCE) ? "A" : "_",
+					       (clock_time.flags & DCFB_DST) ? "D" : "_",
+					       (clock_time.flags & DCFB_LEAP) ? "L" : "_",
+					       (lasterror < 0) ? '-' : '+', l_abs(lasterror) / 1000000, l_abs(lasterror) % 1000000
+					       );
+
+					if (trace && (i == 0))
+					{
+						PRINTF("\n");
+						errs++;
+					}
+					lasterror = usecerror / (i+1);
+				}
+				else
+				{
+					lasterror = 0; /* we cannot calculate phase errors on bad reception */
+				}
+
+				PRINTF("\r");
+
+				if (i < 60)
+				{
+					i++;
+				}
+
+				tlast = tt;
+
+				if (interactive)
+				    fflush(stdout);
+			}
+		} while ((rrc == -1) && (errno == EINTR));
+      
+		/*
+		 * lost IO - sorry guys
+		 */
+		syslog(LOG_ERR, "TERMINATING - cannot read from device %s (%m)", file);
+
+		(void)close(fd);
+	}
+
+	closelog();
+  
+	return 0;
+}