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freebsd-dev/usr.sbin/xntpd/parse/util/dcfd.c
Jordan K. Hubbard dd77c4bc54 Support for the Boeder DCF77 Receiver 
Submitted by: Vincenzo Capuano <VCAPUANO@VMPROFS.ESOC.ESA.DE>
1995-07-21 13:04:07 +00:00

1627 lines
38 KiB
C
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/*
* /src/NTP/REPOSITORY/v3/parse/util/dcfd.c,v 3.18 1994/05/12 12:49:23 kardel Exp
*
* dcfd.c,v 3.18 1994/05/12 12:49:23 kardel Exp
*
* Ported to FreeBSD 2.0 1995/03/20 by Vincenzo Capuano
*
* DCF77 100/200ms pulse synchronisation daemon program (via 50Baud serial line)
*
* Features:
* DCF77 decoding
* NTP loopfilter logic for local clock
* interactive display for debugging
*
* Lacks:
* Leap second handling (at that level you should switch to xntp3 - really!)
*
* Copyright (c) 1993,1994
* Frank Kardel, Friedrich-Alexander Universitaet Erlangen-Nuernberg
*
* 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.
*/
#include <unistd.h>
#include <stdio.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/signal.h>
#include <sys/errno.h>
#include <syslog.h>
/*
* NTP compilation environment
*/
#ifdef USE_PROTOTYPES
#include "ntp_stdlib.h"
#include <signal.h>
#include <stdio.h>
#endif
#ifdef SYS_LINUX
#include "ntp_timex.h"
#endif
/*
* select which terminal handling to use (currently only SysV variants)
*/
#if defined(HAVE_TERMIOS) || defined(STREAM)
#include <termios.h>
#define TTY_GETATTR(_FD_, _ARG_) tcgetattr((_FD_), (_ARG_))
#define TTY_SETATTR(_FD_, _ARG_) tcsetattr((_FD_), TCSANOW, (_ARG_))
#endif
#if defined(HAVE_TERMIO) || 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
#ifndef TTY_GETATTR
MUST DEFINE ONE OF "HAVE_TERMIOS" or "HAVE_TERMIO"
#endif
#ifndef dysize
#define dysize(_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 = 1000000 - (-(_a_)->tv_usec % 1000000); \
}
#define timeradd(_a_, _b_) \
(_a_)->tv_sec += (_b_)->tv_sec; \
(_a_)->tv_usec += (_b_)->tv_usec; \
timernormalize((_a_))
#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_) PRINTF _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 drift_comp = 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 abs() function
*/
#define 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 field 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(buf, idx)
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(buf, idx)
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(buffer, size, clock)
register unsigned char *buffer;
register int size;
register clocktime_t *clock;
{
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->flags = 0;
clock->usecond= 0;
clock->second = 0;
clock->minute = ext_bf(buffer, DCF_M10);
clock->minute = TIMES10(clock->minute) + ext_bf(buffer, DCF_M1);
clock->hour = ext_bf(buffer, DCF_H10);
clock->hour = TIMES10(clock->hour) + ext_bf(buffer, DCF_H1);
clock->day = ext_bf(buffer, DCF_D10);
clock->day = TIMES10(clock->day) + ext_bf(buffer, DCF_D1);
clock->month = ext_bf(buffer, DCF_MO0);
clock->month = TIMES10(clock->month) + ext_bf(buffer, DCF_MO);
clock->year = ext_bf(buffer, DCF_Y10);
clock->year = TIMES10(clock->year) + ext_bf(buffer, DCF_Y1);
clock->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->utcoffset = -60;
break;
case DCF_Z_MED:
clock->flags |= DCFB_DST;
clock->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->flags |= DCFB_ANNOUNCE;
if (ext_bf(buffer, DCF_A2))
clock->flags |= DCFB_LEAP;
if (ext_bf(buffer, DCF_R))
clock->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(buffer, size, clock)
register unsigned char *buffer;
register int size;
register clocktime_t *clock;
{
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 = ~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) : rtc;
}
/*-----------------------------------------------------------------------
* convert a wall clock time description of DCF77 to a Unix time (seconds
* since 1.1. 1970 UTC)
*/
time_t
dcf_to_unixtime(clock, cvtrtc)
register clocktime_t *clock;
register unsigned long *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->year < 100)
clock->year += 1900;
/*
* assume that we convert timecode within the unix/UTC epoch -
* prolonges validity of 2 digit years
*/
if (clock->year < 1994)
clock->year += 100; /* XXX this will do it till <2094 */
/*
* must have been a really negative year code - drop it
*/
if (clock->year < 0)
{
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 = (clock->year - 1970) * 365;
t += (clock->year >> 2) - (1970 >> 2);
t -= clock->year / 400 - 1970 / 400;
/* month */
if (clock->month <= 0 || clock->month > 12)
{
SETRTC(CVT_FAIL|CVT_BADDATE);
return -1; /* bad month */
}
/* adjust current leap year */
if (clock->month >= 3 && dysize(clock->year) == 366)
t++;
/*
* collect days from months excluding the current one
*/
for (i = 1; i < clock->month; i++)
{
t += days_of_month[i];
}
/* day */
if (clock->day < 1 || ((clock->month == 2 && dysize(clock->year) == 366) ?
clock->day > 29 : clock->day > days_of_month[clock->month]))
{
SETRTC(CVT_FAIL|CVT_BADDATE);
return -1; /* bad day */
}
/*
* collect days from date excluding the current one
*/
t += clock->day - 1;
/* hour */
if (clock->hour < 0 || clock->hour >= 24)
{
SETRTC(CVT_FAIL|CVT_BADTIME);
return -1; /* bad hour */
}
/*
* calculate hours from 1. 1. 1970
*/
t = TIMES24(t) + clock->hour;
/* min */
if (clock->minute < 0 || clock->minute > 59)
{
SETRTC(CVT_FAIL|CVT_BADTIME);
return -1; /* bad min */
}
/*
* calculate minutes from 1. 1. 1970
*/
t = TIMES60(t) + clock->minute;
/* sec */
/*
* calculate UTC in minutes
*/
t += clock->utcoffset;
if (clock->second < 0 || clock->second > 60) /* allow for LEAPs */
{
SETRTC(CVT_FAIL|CVT_BADTIME);
return -1; /* bad sec */
}
/*
* calculate UTC in seconds - phew !
*/
t = TIMES60(t) + clock->second;
/* done */
return t;
}
/*-----------------------------------------------------------------------
* cheap half baked 1/0 decision - for interactive operation only
*/
static char type(c)
unsigned char c;
{
c ^= 0xFF;
return (c > 0xF);
}
/*-----------------------------------------------------------------------
* week day representation
*/
static char *wday[8] =
{
"??",
"Mo",
"Tu",
"We",
"Th",
"Fr",
"Sa",
"Su"
};
/*-----------------------------------------------------------------------
* generate a string representation for a timeval
*/
static char * pr_timeval(val)
struct timeval *val;
{
static char buf[20];
if (val->tv_sec == 0)
sprintf(buf, "%c0.%06ld", (val->tv_usec < 0) ? '-' : '+', (long int)abs(val->tv_usec));
else
sprintf(buf, "%ld.%06ld", (long int)val->tv_sec, (long int)abs(val->tv_usec));
return buf;
}
/*-----------------------------------------------------------------------
* correct the current time by an offset by setting the time rigorously
*/
static void set_time(offset)
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(offset)
register 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(drift_file)
char *drift_file;
{
FILE *df;
df = fopen(drift_file, "r");
if (df != NULL)
{
int idrift, fdrift;
fscanf(df, "%4d.%03d", &idrift, &fdrift);
fclose(df);
LPRINTF("read_drift: %d.%03d ppm ", idrift, fdrift);
drift_comp = idrift << USECSCALE;
fdrift = (fdrift << USECSCALE) / 1000;
drift_comp += fdrift & (1<<USECSCALE);
LPRINTF("read_drift: drift_comp %ld ", (long int)drift_comp);
}
}
/*-----------------------------------------------------------------------
* write out the current drift value
*/
static void update_drift(drift_file, offset, reftime)
char *drift_file;
long offset;
time_t reftime;
{
FILE *df;
df = fopen(drift_file, "w");
if (df != NULL)
{
int idrift = R_SHIFT(drift_comp, USECSCALE);
int fdrift = drift_comp & ((1<<USECSCALE)-1);
LPRINTF("update_drift: drift_comp %ld ", (long int)drift_comp);
fdrift = (fdrift * 1000) / (1<<USECSCALE);
fprintf(df, "%4d.%03d %c%ld.%06ld %.24s\n", idrift, fdrift,
(offset < 0) ? '-' : '+', (long int)(abs(offset) / 1000000),
(long int)(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(offset, drift_file, reftime)
struct timeval *offset;
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 = abs(toffset.tv_sec);
toffset.tv_usec = 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;
drift_comp += R_SHIFT(usecoffset << USECSCALE, TIMECONSTANT+TIMECONSTANT+FREQ_WEIGHT-tmp);
if (drift_comp > MAX_DRIFT) /* clamp into interval */
drift_comp = MAX_DRIFT;
else
if (drift_comp < -MAX_DRIFT)
drift_comp = -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(drift_comp, USECSCALE), (long int)drift_comp);
}
/*-----------------------------------------------------------------------
* adjust the clock by a small mount to simulate frequency correction
*/
static void periodic_adjust()
{
register long adjustment;
adjustments++;
adjustment = R_SHIFT(clock_adjust, PHASE_WEIGHT);
clock_adjust -= adjustment;
adjustment += R_SHIFT(drift_comp, USECSCALE+ADJINTERVAL);
adj_time(adjustment);
}
/*-----------------------------------------------------------------------
* control synchronisation status (warnings) and do periodic adjusts
* (frequency control simulation)
*/
static void tick()
{
static unsigned long last_notice = 0;
#ifndef SV_ONSTACK
(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()
{
int s;
if (fork())
exit(0);
for (s = 0; s < 3; s++)
(void) close(s);
(void) open("/", 0);
(void) dup2(0, 1);
(void) dup2(0, 2);
#if defined(NTP_POSIX_SOURCE) || defined(_POSIX_)
(void) setsid();
#else /* _POSIX_ */
#ifndef BSD
(void) setpgrp();
#else /* BSD */
(void) setpgrp(0, getpid());
#endif /* BSD */
#endif /* _POSIX_ */
#if defined(hpux)
if (fork())
exit(0);
#endif /* hpux */
}
/*-----------------------------------------------------------------------
* list possible arguments and options
*/
static void usage(program)
char *program;
{
fprintf(stderr, "usage: %s [-f] [-l] [-t] [-i] [-o] [-d <drift_file>] <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-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");
}
/*-----------------------------------------------------------------------
* main loop - argument interpreter / setup / main loop
*/
int
main(argc, argv)
int argc;
char **argv;
{
unsigned char c;
char **a = argv;
int ac = argc;
char *file = NULL;
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;
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
*/
#if defined(SYS_FREEBSD) && defined(BOEDER)
fd = open(file, O_RDONLY | O_NONBLOCK);
#else
fd = open(file, O_RDONLY);
#endif
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; /* wall clock time */
time_t utc_time = 0;
time_t last_utc_time = 0;
long usecerror = 0;
long lasterror = 0;
#if defined(HAVE_TERMIOS) || defined(STREAM)
struct termios term;
#endif
#if defined(HAVE_TERMIO) || defined(HAVE_SYSV_TTYS)
struct termio term;
#endif
int rtc = CVT_NONE;
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;
#if defined(SYS_FREEBSD)
term.c_cflag = CS8|CREAD|CLOCAL|PARENB;
term.c_iflag = 0;
#else
term.c_cflag = B50|CS8|CREAD|CLOCAL|PARENB;
term.c_iflag = IGNPAR;
#endif
term.c_oflag = 0;
term.c_lflag = 0;
#if defined(SYS_FREEBSD)
if (cfsetspeed(&term, B50) == -1)
perror("cfsetspeed");
#endif
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 SV_ONSTACK
{
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
(void) signal(SIGALRM, tick);
#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
#if defined(SYS_FREEBSD) && defined(BOEDER)
if (fcntl(fd, F_SETFL, fcntl(fd, F_GETFL, 0) & ~O_NONBLOCK) == -1)
perror("F_SETFL");
if (ioctl(fd, TIOCCDTR, 0) == -1)
perror("TIOCCDTR");
#endif
PRINTF(" DCF77 monitor - Copyright 1993,1994, Frank Kardel\n\n");
syslog(LOG_NOTICE, "Starting on %s", file);
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(buf, i, &clock)) != 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, &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
*/
#if defined(BOEDER)
if (abs(utc_time - tt.tv_sec) > 10)
{
time_offset.tv_sec = utc_time - tt.tv_sec;
time_offset.tv_usec = 0;
}
else
{
time_offset.tv_sec = lasterror / 1000000;
time_offset.tv_usec = lasterror % 1000000;
}
#else
time_offset.tv_sec = lasterror / 1000000;
time_offset.tv_usec = lasterror % 1000000;
#endif
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.wday],
clock.hour, clock.minute, i, clock.day, clock.month,
clock.year,
(clock.flags & DCFB_ALTERNATE) ? "R" : "_",
(clock.flags & DCFB_ANNOUNCE) ? "A" : "_",
(clock.flags & DCFB_DST) ? "D" : "_",
(clock.flags & DCFB_LEAP) ? "L" : "_",
(lasterror < 0) ? '-' : '+', abs(lasterror) / 1000000, 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;
}
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