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freebsd/contrib/ntp/ntpd/refclock_dumbclock.c
2004-07-20 15:01:56 +00:00

386 lines
8.5 KiB
C

/*
* refclock_dumbclock - clock driver for a unknown time distribution system
* that only provides hh:mm:ss (in local time, yet!).
*/
/*
* Must interpolate back to local time. Very annoying.
*/
#define GET_LOCALTIME
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#if defined(SYS_WINNT)
#undef close
#define close closesocket
#endif
#if defined(REFCLOCK) && defined(CLOCK_DUMBCLOCK)
#include "ntpd.h"
#include "ntp_io.h"
#include "ntp_refclock.h"
#include "ntp_calendar.h"
#include "ntp_stdlib.h"
#include <stdio.h>
#include <ctype.h>
/*
* This driver supports a generic dumb clock that only outputs hh:mm:ss,
* in local time, no less.
*
* Input format:
*
* hh:mm:ss <cr>
*
* hh:mm:ss -- what you'd expect, with a 24 hour clock. (Heck, that's the only
* way it could get stupider.) We take time on the <cr>.
*
* The original source of this module was the WWVB module.
*/
/*
* Interface definitions
*/
#define DEVICE "/dev/dumbclock%d" /* device name and unit */
#define SPEED232 B9600 /* uart speed (9600 baud) */
#define PRECISION (-13) /* precision assumed (about 100 us) */
#define REFID "dumbclock" /* reference ID */
#define DESCRIPTION "Dumb clock" /* WRU */
/*
* Insanity check. Since the time is local, we need to make sure that during midnight
* transitions, we can convert back to Unix time. If the conversion results in some number
* worse than this number of seconds away, assume the next day and retry.
*/
#define INSANE_SECONDS 3600
/*
* Dumb clock control structure
*/
struct dumbclock_unit {
u_char tcswitch; /* timecode switch */
l_fp laststamp; /* last receive timestamp */
u_char lasthour; /* last hour (for monitor) */
u_char linect; /* count ignored lines (for monitor */
struct tm ymd; /* struct tm for y/m/d only */
};
/*
* Function prototypes
*/
static int dumbclock_start P((int, struct peer *));
static void dumbclock_shutdown P((int, struct peer *));
static void dumbclock_receive P((struct recvbuf *));
#if 0
static void dumbclock_poll P((int, struct peer *));
#endif
/*
* Transfer vector
*/
struct refclock refclock_dumbclock = {
dumbclock_start, /* start up driver */
dumbclock_shutdown, /* shut down driver */
noentry, /* poll the driver -- a nice fabrication */
noentry, /* not used */
noentry, /* not used */
noentry, /* not used */
NOFLAGS /* not used */
};
/*
* dumbclock_start - open the devices and initialize data for processing
*/
static int
dumbclock_start(
int unit,
struct peer *peer
)
{
register struct dumbclock_unit *up;
struct refclockproc *pp;
int fd;
char device[20];
struct tm *tm_time_p;
time_t now;
/*
* Open serial port. Don't bother with CLK line discipline, since
* it's not available.
*/
(void)sprintf(device, DEVICE, unit);
#ifdef DEBUG
if (debug)
printf ("starting Dumbclock with device %s\n",device);
#endif
fd = refclock_open(device, SPEED232, 0);
if (fd < 0)
return (0);
/*
* Allocate and initialize unit structure
*/
up = (struct dumbclock_unit *)emalloc(sizeof(struct dumbclock_unit));
if (up == NULL) {
(void) close(fd);
return (0);
}
memset((char *)up, 0, sizeof(struct dumbclock_unit));
pp = peer->procptr;
pp->unitptr = (caddr_t)up;
pp->io.clock_recv = dumbclock_receive;
pp->io.srcclock = (caddr_t)peer;
pp->io.datalen = 0;
pp->io.fd = fd;
if (!io_addclock(&pp->io)) {
(void) close(fd);
free(up);
return (0);
}
time(&now);
#ifdef GET_LOCALTIME
tm_time_p = localtime(&now);
#else
tm_time_p = gmtime(&now);
#endif
if (tm_time_p)
{
up->ymd = *tm_time_p;
}
else
{
return 0;
}
/*
* Initialize miscellaneous variables
*/
peer->precision = PRECISION;
pp->clockdesc = DESCRIPTION;
memcpy((char *)&pp->refid, REFID, 4);
return (1);
}
/*
* dumbclock_shutdown - shut down the clock
*/
static void
dumbclock_shutdown(
int unit,
struct peer *peer
)
{
register struct dumbclock_unit *up;
struct refclockproc *pp;
pp = peer->procptr;
up = (struct dumbclock_unit *)pp->unitptr;
io_closeclock(&pp->io);
free(up);
}
/*
* dumbclock_receive - receive data from the serial interface
*/
static void
dumbclock_receive(
struct recvbuf *rbufp
)
{
struct dumbclock_unit *up;
struct refclockproc *pp;
struct peer *peer;
l_fp trtmp; /* arrival timestamp */
int hours; /* hour-of-day */
int minutes; /* minutes-past-the-hour */
int seconds; /* seconds */
int temp; /* int temp */
int got_good; /* got a good time flag */
/*
* Initialize pointers and read the timecode and timestamp
*/
peer = (struct peer *)rbufp->recv_srcclock;
pp = peer->procptr;
up = (struct dumbclock_unit *)pp->unitptr;
temp = refclock_gtlin(rbufp, pp->a_lastcode, BMAX, &trtmp);
if (temp == 0) {
if (up->tcswitch == 0) {
up->tcswitch = 1;
up->laststamp = trtmp;
} else
up->tcswitch = 0;
return;
}
pp->lencode = (u_short)temp;
pp->lastrec = up->laststamp;
up->laststamp = trtmp;
up->tcswitch = 1;
#ifdef DEBUG
if (debug)
printf("dumbclock: timecode %d %s\n",
pp->lencode, pp->a_lastcode);
#endif
/*
* We get down to business. Check the timecode format...
*/
got_good=0;
if (sscanf(pp->a_lastcode,"%02d:%02d:%02d",
&hours,&minutes,&seconds) == 3)
{
struct tm *gmtp;
struct tm *lt_p;
time_t asserted_time; /* the SPM time based on the composite time+date */
struct tm asserted_tm; /* the struct tm of the same */
int adjyear;
int adjmon;
int reality_delta;
time_t now;
/*
* Convert to GMT for sites that distribute localtime. This
* means we have to figure out what day it is. Easier said
* than done...
*/
asserted_tm.tm_year = up->ymd.tm_year;
asserted_tm.tm_mon = up->ymd.tm_mon;
asserted_tm.tm_mday = up->ymd.tm_mday;
asserted_tm.tm_hour = hours;
asserted_tm.tm_min = minutes;
asserted_tm.tm_sec = seconds;
asserted_tm.tm_isdst = -1;
#ifdef GET_LOCALTIME
asserted_time = mktime (&asserted_tm);
time(&now);
#else
#include "GMT unsupported for dumbclock!"
#endif
reality_delta = asserted_time - now;
/*
* We assume that if the time is grossly wrong, it's because we got the
* year/month/day wrong.
*/
if (reality_delta > INSANE_SECONDS)
{
asserted_time -= SECSPERDAY; /* local clock behind real time */
}
else if (-reality_delta > INSANE_SECONDS)
{
asserted_time += SECSPERDAY; /* local clock ahead of real time */
}
lt_p = localtime(&asserted_time);
if (lt_p)
{
up->ymd = *lt_p;
}
else
{
refclock_report (peer, CEVNT_FAULT);
return;
}
if ((gmtp = gmtime (&asserted_time)) == NULL)
{
refclock_report (peer, CEVNT_FAULT);
return;
}
adjyear = gmtp->tm_year+1900;
adjmon = gmtp->tm_mon+1;
pp->day = ymd2yd (adjyear, adjmon, gmtp->tm_mday);
pp->hour = gmtp->tm_hour;
pp->minute = gmtp->tm_min;
pp->second = gmtp->tm_sec;
#ifdef DEBUG
if (debug)
printf ("time is %04d/%02d/%02d %02d:%02d:%02d UTC\n",
adjyear,adjmon,gmtp->tm_mday,pp->hour,pp->minute,
pp->second);
#endif
got_good=1;
}
if (!got_good)
{
if (up->linect > 0)
up->linect--;
else
refclock_report(peer, CEVNT_BADREPLY);
return;
}
/*
* Process the new sample in the median filter and determine the
* timecode timestamp.
*/
if (!refclock_process(pp)) {
refclock_report(peer, CEVNT_BADTIME);
return;
}
pp->lastref = pp->lastrec;
refclock_receive(peer);
record_clock_stats(&peer->srcadr, pp->a_lastcode);
up->lasthour = (u_char)pp->hour;
}
#if 0
/*
* dumbclock_poll - called by the transmit procedure
*/
static void
dumbclock_poll(
int unit,
struct peer *peer
)
{
register struct dumbclock_unit *up;
struct refclockproc *pp;
char pollchar;
/*
* Time to poll the clock. The Chrono-log clock is supposed to
* respond to a 'T' by returning a timecode in the format(s)
* specified above. Ours does (can?) not, but this seems to be
* an installation-specific problem. This code is dyked out,
* but may be re-enabled if anyone ever finds a Chrono-log that
* actually listens to this command.
*/
#if 0
pp = peer->procptr;
up = (struct dumbclock_unit *)pp->unitptr;
if (peer->reach == 0)
refclock_report(peer, CEVNT_TIMEOUT);
if (up->linect > 0)
pollchar = 'R';
else
pollchar = 'T';
if (write(pp->io.fd, &pollchar, 1) != 1)
refclock_report(peer, CEVNT_FAULT);
else
pp->polls++;
#endif
}
#endif
#else
int refclock_dumbclock_bs;
#endif /* REFCLOCK */