refclock_jupiter.c

网络时间协议NTP 源码 版本v4.2.0b 该源码用于linux平台下

			}

			/*
			 * There appears to be a firmware bug related
			 * to the pulse message; in addition to the one
			 * per second messages, we get an extra pulse
			 * message once an hour (on the anniversary of
			 * the cold start). It seems to come 200 ms
			 * after the one requested. So if we've seen a
			 * pulse message in the last 210 ms, we skip
			 * this one.
			 */
			laststime = instance->stime;
			instance->stime = DS2UI(((struct jpulse *)sp)->stime);
			if (laststime != 0 && instance->stime - laststime <= 21) {
				jupiter_debug(peer, "jupiter_receive", 
				"avoided firmware bug (stime %.2f, laststime %.2f)",
				(double)instance->stime * 0.01, (double)laststime * 0.01);
				break;
			}

			/* Retrieve pps timestamp */
			ppsret = jupiter_pps(instance);

			/*
			 * Add one second if msg received early
			 * (i.e. before limit, a.k.a. fudgetime2) in
			 * the second.
			 */
			L_SUB(&tstamp, &pp->lastrec);
			if (!L_ISGEQ(&tstamp, &instance->limit))
				++pp->lastrec.l_ui;

			/* Parse timecode (even when there's no pps) */
			last_timecode = instance->timecode;
			if ((cp = jupiter_parse_t(instance, sp)) != NULL) {
				jupiter_debug(peer,
				    "jupiter_receive", "pulse: %s", cp);
				break;
			}

			/* Bail if we didn't get a pps timestamp */
			if (ppsret)
				break;

			/* Bail if we don't have the last timecode yet */
			if (last_timecode == 0)
				break;

			/* Add the new sample to a median filter */
			tstamp.l_ui = JAN_1970 + last_timecode;
			tstamp.l_uf = 0;

			refclock_process_offset(pp, tstamp, pp->lastrec, pp->fudgetime1);

			/*
			 * The clock will blurt a timecode every second
			 * but we only want one when polled.  If we
			 * havn't been polled, bail out.
			 */
			if (!instance->polled)
				break;
			instance->polled = 0;

			/*
			 * It's a live one!  Remember this time.
			 */

			pp->lastref = pp->lastrec;
			refclock_receive(peer);

			/*
			 * If we get here - what we got from the clock is
			 * OK, so say so
			 */
			refclock_report(peer, CEVNT_NOMINAL);

			/*
			 * We have succeeded in answering the poll.
			 * Turn off the flag and return
			 */
			instance->polled = 0;
			break;

		case JUPITER_O_GPOS:
			if (size != sizeof(struct jgpos)) {
				jupiter_debug(peer,
				    "jupiter_receive", "gpos: len %d != %u",
				    size, (int)sizeof(struct jgpos));
				refclock_report(peer, CEVNT_BADREPLY);
				break;
			}

			if ((cp = jupiter_parse_gpos(instance, sp)) != NULL) {
				jupiter_debug(peer,
				    "jupiter_receive", "gpos: %s", cp);
				break;
			}
			break;

		case JUPITER_O_ID:
			if (size != sizeof(struct jid)) {
				jupiter_debug(peer,
				    "jupiter_receive", "id: len %d != %u",
				    size, (int)sizeof(struct jid));
				refclock_report(peer, CEVNT_BADREPLY);
				break;
			}
			/*
			 * If we got this message because the Jupiter
			 * just powered instance, it needs to be reconfigured.
			 */
			ip = (struct jid *)sp;
			jupiter_debug(peer,
			    "jupiter_receive", "%s chan ver %s, %s (%s)",
			    ip->chans, ip->vers, ip->date, ip->opts);
			msyslog(LOG_DEBUG,
			    "jupiter_receive: %s chan ver %s, %s (%s)",
			    ip->chans, ip->vers, ip->date, ip->opts);
			if (instance->wantid)
				instance->wantid = 0;
			else {
				jupiter_debug(peer,
				    "jupiter_receive", "reset receiver");
				jupiter_config(instance);
				/*
				 * Restore since jupiter_config() just
				 * zeroed it
				 */
				instance->ssize = cc;
			}
			break;

		default:
			jupiter_debug(peer,
			    "jupiter_receive", "unknown message id %d",
			    getshort(hp->id));
			break;
		}
		instance->ssize -= cc;
		if (instance->ssize < 0) {
			fprintf(stderr, "jupiter_recv: negative ssize!\n");
			abort();
		} else if (instance->ssize > 0)
			memcpy(instance->sbuf, (u_char *)instance->sbuf + cc, instance->ssize);
	}
}

static char *
jupiter_parse_t(struct instance *instance, u_short *sp)
{
	struct tm *tm;
	char *cp;
	struct jpulse *jp;
	u_int32 sweek;
	time_t last_timecode;
	u_short flags;

	jp = (struct jpulse *)sp;

	/* The timecode is presented as seconds into the current GPS week */
	sweek = DS2UI(jp->sweek) % WEEKSECS;

	/*
	 * If we don't know the current GPS week, calculate it from the
	 * current time. (It's too bad they didn't include this
	 * important value in the pulse message). We'd like to pick it
	 * up from one of the other messages like gpos or chan but they
	 * don't appear to be synchronous with time keeping and changes
	 * too soon (something like 10 seconds before the new GPS
	 * week).
	 *
	 * If we already know the current GPS week, increment it when
	 * we wrap into a new week.
	 */
	if (instance->gweek == 0) {
		if (!instance->gpos_gweek) {
			return ("jupiter_parse_t: Unknown gweek");
		}

		instance->gweek = instance->gpos_gweek;

		/*
		 * Fix warps. GPOS has GPS time and PULSE has UTC.
		 * Plus, GPOS need not be completely in synch with
		 * the PPS signal.
		 */
		if (instance->gpos_sweek >= sweek) {
			if ((instance->gpos_sweek - sweek) > WEEKSECS / 2)
				++instance->gweek;
		}
		else {
			if ((sweek - instance->gpos_sweek) > WEEKSECS / 2)
				--instance->gweek;
		}
	}
	else if (sweek == 0 && instance->lastsweek == WEEKSECS - 1) {
		++instance->gweek;
		jupiter_debug(instance->peer,
		    "jupiter_parse_t", "NEW gps week %u", instance->gweek);
	}

	/*
	 * See if the sweek stayed the same (this happens when there is
	 * no pps pulse).
	 *
	 * Otherwise, look for time warps:
	 *
	 *   - we have stored at least one lastsweek and
	 *   - the sweek didn't increase by one and
	 *   - we didn't wrap to a new GPS week
	 *
	 * Then we warped.
	 */
	if (instance->lastsweek == sweek)
		jupiter_debug(instance->peer,
		    "jupiter_parse_t", "gps sweek not incrementing (%d)",
		    sweek);
	else if (instance->lastsweek != 2 * WEEKSECS &&
	    instance->lastsweek + 1 != sweek &&
	    !(sweek == 0 && instance->lastsweek == WEEKSECS - 1))
		jupiter_debug(instance->peer,
		    "jupiter_parse_t", "gps sweek jumped (was %d, now %d)",
		    instance->lastsweek, sweek);
	instance->lastsweek = sweek;

	/* This timecode describes next pulse */
	last_timecode = instance->timecode;
	instance->timecode =
	    GPS_EPOCH + (instance->gweek * WEEKSECS) + sweek;

	if (last_timecode == 0)
		/* XXX debugging */
		jupiter_debug(instance->peer,
		    "jupiter_parse_t", "UTC <none> (gweek/sweek %u/%u)",
		    instance->gweek, sweek);
	else {
		/* XXX debugging */
		tm = gmtime(&last_timecode);
		cp = asctime(tm);

		jupiter_debug(instance->peer,
		    "jupiter_parse_t", "UTC %.24s (gweek/sweek %u/%u)",
		    cp, instance->gweek, sweek);

		/* Billboard last_timecode (which is now the current time) */
		instance->peer->procptr->year   = tm->tm_year + 1900;
		instance->peer->procptr->day    = tm->tm_yday + 1;
		instance->peer->procptr->hour   = tm->tm_hour;
		instance->peer->procptr->minute = tm->tm_min;
		instance->peer->procptr->second = tm->tm_sec;
	}

	flags = getshort(jp->flags);

	/* Toss if not designated "valid" by the gps */
	if ((flags & JUPITER_O_PULSE_VALID) == 0) {
		refclock_report(instance->peer, CEVNT_BADTIME);
		return ("time mark not valid");
	}

	/* We better be sync'ed to UTC... */
	if ((flags & JUPITER_O_PULSE_UTC) == 0) {
		refclock_report(instance->peer, CEVNT_BADTIME);
		return ("time mark not sync'ed to UTC");
	}

	return (NULL);
}

static char *
jupiter_parse_gpos(struct instance *instance, u_short *sp)
{
	struct jgpos *jg;
	time_t t;
	struct tm *tm;
	char *cp;

	jg = (struct jgpos *)sp;

	if (jg->navval != 0) {
		/*
		 * Solution not valid. Use caution and refuse
		 * to determine GPS week from this message.
		 */
		instance->gpos_gweek = 0;
		instance->gpos_sweek = 0;
		return ("Navigation solution not valid");
	}

	instance->gpos_gweek = jg->gweek;
	instance->gpos_sweek = DS2UI(jg->sweek);
	while(instance->gpos_sweek >= WEEKSECS) {
		instance->gpos_sweek -= WEEKSECS;
		++instance->gpos_gweek;
	}
	instance->gweek = 0;

	t = GPS_EPOCH + (instance->gpos_gweek * WEEKSECS) + instance->gpos_sweek;
	tm = gmtime(&t);
	cp = asctime(tm);

	jupiter_debug(instance->peer,
		"jupiter_parse_g", "GPS %.24s (gweek/sweek %u/%u)",
		cp, instance->gpos_gweek, instance->gpos_sweek);
	return (NULL);
}

/*
 * jupiter_debug - print debug messages
 */
#if defined(__STDC__) || defined(SYS_WINNT)
static void
jupiter_debug(struct peer *peer, char *function, char *fmt, ...)
#else
static void
jupiter_debug(peer, function, fmt, va_alist)
	struct peer *peer;
	char *function;
	char *fmt;
#endif /* __STDC__ */
{
	char buffer[200];
	va_list ap;

#if defined(__STDC__) || defined(SYS_WINNT)
	va_start(ap, fmt);
#else
	va_start(ap);
#endif /* __STDC__ */
	/*
	 * Print debug message to stdout
	 * In the future, we may want to get get more creative...
	 */
	vsnprintf(buffer, sizeof(buffer), fmt, ap);
	record_clock_stats(&(peer->srcadr), buffer);
	if (debug) {
		fprintf(stdout, "%s: ", function);
		fprintf(stdout, buffer);
		fprintf(stdout, "\n");
		fflush(stdout);
	}

	va_end(ap);
}

/* Checksum and transmit a message to the Jupiter */
static char *
jupiter_send(struct instance *instance, struct jheader *hp)
{
	u_int len, size;
	int cc;
	u_short *sp;
	static char errstr[132];

	size = sizeof(*hp);
	hp->hsum = putshort(jupiter_cksum((u_short *)hp,
	    (size / sizeof(u_short)) - 1));
	len = getshort(hp->len);
	if (len > 0) {
		sp = (u_short *)(hp + 1);
		sp[len] = putshort(jupiter_cksum(sp, len));
		size += (len + 1) * sizeof(u_short);
	}

	if ((cc = write(instance->peer->procptr->io.fd, (char *)hp, size)) < 0) {
		(void)sprintf(errstr, "write: %s", strerror(errno));
		return (errstr);
	} else if (cc != size) {
		(void)sprintf(errstr, "short write (%d != %d)", cc, size);
		return (errstr);
	}
	return (NULL);
}

/* Request periodic message output */
static struct {
	struct jheader jheader;
	struct jrequest jrequest;
} reqmsg = {
	{ putshort(JUPITER_SYNC), 0,
	    putshort((sizeof(struct jrequest) / sizeof(u_short)) - 1),
	    0, JUPITER_FLAG_REQUEST | JUPITER_FLAG_NAK |
	    JUPITER_FLAG_CONN | JUPITER_FLAG_LOG, 0 },
	{ 0, 0, 0, 0 }
};

/* An interval of zero means to output on trigger */
static void
jupiter_reqmsg(struct instance *instance, u_int id,
    u_int interval)
{
	struct jheader *hp;
	struct jrequest *rp;
	char *cp;

	hp = &reqmsg.jheader;
	hp->id = putshort(id);
	rp = &reqmsg.jrequest;
	rp->trigger = putshort(interval == 0);
	rp->interval = putshort(interval);
	if ((cp = jupiter_send(instance, hp)) != NULL)
		jupiter_debug(instance->peer, "jupiter_reqmsg", "%u: %s", id, cp);
}

/* Cancel periodic message output */
static struct jheader canmsg = {
	putshort(JUPITER_SYNC), 0, 0, 0,
	JUPITER_FLAG_REQUEST | JUPITER_FLAG_NAK | JUPITER_FLAG_DISC,
	0
};

static void
jupiter_canmsg(struct instance *instance, u_int id)
{
	struct jheader *hp;
	char *cp;

	hp = &canmsg;
	hp->id = putshort(id);
	if ((cp = jupiter_send(instance, hp)) != NULL)
		jupiter_debug(instance->peer, "jupiter_canmsg", "%u: %s", id, cp);
}

/* Request a single message output */
static struct jheader reqonemsg = {
	putshort(JUPITER_SYNC), 0, 0, 0,
	JUPITER_FLAG_REQUEST | JUPITER_FLAG_NAK | JUPITER_FLAG_QUERY,
	0
};

static void
jupiter_reqonemsg(struct instance *instance, u_int id)
{
	struct jheader *hp;
	char *cp;

	hp = &reqonemsg;
	hp->id = putshort(id);
	if ((cp = jupiter_send(instance, hp)) != NULL)
		jupiter_debug(instance->peer, "jupiter_reqonemsg", "%u: %s", id, cp);
}

/* Set the platform dynamics */
static struct {
	struct jheader jheader;
	struct jplat jplat;
} platmsg = {
	{ putshort(JUPITER_SYNC), putshort(JUPITER_I_PLAT),
	    putshort((sizeof(struct jplat) / sizeof(u_short)) - 1), 0,
	    JUPITER_FLAG_REQUEST | JUPITER_FLAG_NAK, 0 },
	{ 0, 0, 0 }
};

static void
jupiter_platform(struct instance *instance, u_int platform)
{
	struct jheader *hp;
	struct jplat *pp;
	char *cp;

	hp = &platmsg.jheader;
	pp = &platmsg.jplat;
	pp->platform = putshort(platform);
	if ((cp = jupiter_send(instance, hp)) != NULL)
		jupiter_debug(instance->peer, "jupiter_platform", "%u: %s", platform, cp);
}

/* Checksum "len" shorts */
static u_short
jupiter_cksum(u_short *sp, u_int len)
{
	u_short sum, x;

	sum = 0;
	while (len-- > 0) {
		x = *sp++;
		sum += getshort(x);
	}
	return (~sum + 1);
}

/* Return the size of the next message (or zero if we don't have it all yet) */
static int
jupiter_recv(struct instance *instance)
{
	int n, len, size, cc;
	struct jheader *hp;
	u_char *bp;
	u_short *sp;

	/* Must have at least a header's worth */
	cc = sizeof(*hp);
	size = instance->ssize;
	if (size < cc)
		return (0);

	/* Search for the sync short if missing */
	sp = instance->sbuf;
	hp = (struct jheader *)sp;
	if (getshort(hp->sync) != JUPITER_SYNC) {
		/* Wasn't at the front, sync up */
		jupiter_debug(instance->peer, "jupiter_recv", "syncing");
		bp = (u_char *)sp;
		n = size;
		while (n >= 2) {
			if (bp[0] != (JUPITER_SYNC & 0xff)) {
				/*
				jupiter_debug(instance->peer, "{0x%x}", bp[0]);
				*/
				++bp;
				--n;
				continue;
			}
			if (bp[1] == ((JUPITER_SYNC >> 8) & 0xff))
				break;
			/*
			jupiter_debug(instance->peer, "{0x%x 0x%x}", bp[0], bp[1]);
			*/
			bp += 2;
			n -= 2;
		}
		/*
		jupiter_debug(instance->peer, "\n");
		*/
		/* Shuffle data to front of input buffer */
		if (n > 0)
			memcpy(sp, bp, n);
		size = n;
		instance->ssize = size;
		if (size < cc || hp->sync != JUPITER_SYNC)
			return (0);
	}

	if (jupiter_cksum(sp, (cc / sizeof(u_short) - 1)) !=
	    getshort(hp->hsum)) {
	    jupiter_debug(instance->peer, "jupiter_recv", "bad header checksum!");
		/* This is drastic but checksum errors should be rare */
		instance->ssize = 0;
		return (0);
	}

	/* Check for a payload */
	len = getshort(hp->len);
	if (len > 0) {
		n = (len + 1) * sizeof(u_short);
		/* Not enough data yet */
		if (size < cc + n)
			return (0);

		/* Check payload checksum */
		sp = (u_short *)(hp + 1);
		if (jupiter_cksum(sp, len) != getshort(sp[len])) {
			jupiter_debug(instance->peer,
			    "jupiter_recv", "bad payload checksum!");
			/* This is drastic but checksum errors should be rare */
			instance->ssize = 0;
			return (0);
		}
		cc += n;
	}
	return (cc);
}

#else /* not (REFCLOCK && CLOCK_JUPITER && HAVE_PPSAPI) */
int refclock_jupiter_bs;
#endif /* not (REFCLOCK && CLOCK_JUPITER && HAVE_PPSAPI) */