refclock_oncore.c

网络时间协议NTP 源码 版本v4.2.0b 该源码用于linux平台下

	/* OK, we now create the NEW SHMEM. */

	if ((instance->shmemfd = open(instance->shmem_fname, O_RDWR|O_CREAT|O_TRUNC, 0644)) < 0) {
		perror(instance->shmem_fname);
		return;
	}

	/* see how big it needs to be */

	n = 1;
	for (mp=oncore_messages; mp->flag[0]; mp++) {
		mp->shmem = n;
		/* Allocate space for multiplexed almanac, and 0D/2D/3D @@Ea records */
		if (!strcmp(mp->flag, "Cb")) {
			instance->shmem_Cb = n;
			n += (mp->len + 3) * 34;
		}
		if (!strcmp(mp->flag, "Ba")) {
			instance->shmem_Ba = n;
			n += (mp->len + 3) * 3;
		}
		if (!strcmp(mp->flag, "Ea")) {
			instance->shmem_Ea = n;
			n += (mp->len + 3) * 3;
		}
		if (!strcmp(mp->flag, "Ha")) {
			instance->shmem_Ha = n;
			n += (mp->len + 3) * 3;
		}
		n += (mp->len + 3);
	}
	shmem_length = n + 2;
	fprintf(stderr, "ONCORE: SHMEM length: %ld bytes\n", (long) shmem_length);

	buf = malloc(shmem_length);
	if (buf == NULL) {
		perror("malloc");
		close(instance->shmemfd);
		return;
	}

	memset(buf, 0, shmem_length);

	/* next build the new SHMEM buffer in memory */

	for (mp=oncore_messages; mp->flag[0]; mp++) {
		l = mp->shmem;
		buf[l + 0] = mp->len >> 8;
		buf[l + 1] = mp->len & 0xff;
		buf[l + 2] = 0;
		buf[l + 3] = '@';
		buf[l + 4] = '@';
		buf[l + 5] = mp->flag[0];
		buf[l + 6] = mp->flag[1];
		if (!strcmp(mp->flag, "Cb") || !strcmp(mp->flag, "Ba") || !strcmp(mp->flag, "Ea") || !strcmp(mp->flag, "Ha")) {
			if (!strcmp(mp->flag, "Cb"))
				n = 35;
			else
				n = 4;
			for (i=1; i<n; i++) {
				buf[l + i * (mp->len+3) + 0] = mp->len >> 8;
				buf[l + i * (mp->len+3) + 1] = mp->len & 0xff;
				buf[l + i * (mp->len+3) + 2] = 0;
				buf[l + i * (mp->len+3) + 3] = '@';
				buf[l + i * (mp->len+3) + 4] = '@';
				buf[l + i * (mp->len+3) + 5] = mp->flag[0];
				buf[l + i * (mp->len+3) + 6] = mp->flag[1];
			}
		}
	}

	/* we now walk thru the two buffers (shmem_old and buf, soon to become shmem)
	 * copying the data in shmem_old to buf.  When we are done we write it out
	 * and free both buffers.
	 * If the structures change (an addition or deletion) I will stop copying.
	 * The two will be the same unless we add/subtract from the oncore_messages list
	 * so this should work most of the time, and takes a lot less code than doing it right.
	 */

	if (shmem_old) {
		for (cp=buf+4, cp1=shmem_old+4; (n = 256*(*(cp-3)) + *(cp-2));	cp+=(n+3), cp1+=(n+3)) {
			n1 = 256*(*(cp1-3)) + *(cp1-2);
			if (n1 != n || strncmp(cp, cp1, 4))
				break;

			memcpy(cp, cp1, (size_t) n);
		}
		free(shmem_old);
	}

	i = write(instance->shmemfd, buf, shmem_length);
	free(buf);

	if (i != shmem_length) {
		perror(instance->shmem_fname);
		close(instance->shmemfd);
		return;
	}

	instance->shmem = (u_char *) mmap(0, shmem_length,
		PROT_READ | PROT_WRITE,
#ifdef MAP_HASSEMAPHORE
		MAP_HASSEMAPHORE |
#endif
		MAP_SHARED, instance->shmemfd, (off_t)0);

	if (instance->shmem == (u_char *)MAP_FAILED) {
		instance->shmem = 0;
		close(instance->shmemfd);
		return;
	}

	sprintf(Msg, "SHMEM (size = %ld) is CONFIGURED and available as %s",
		(long) shmem_length, instance->shmem_fname);
	record_clock_stats(&(instance->peer->srcadr), Msg);
}
#endif /* ONCORE_SHMEM_STATUS */



/*
 * Read Input file if it exists.
 */

static void
oncore_read_config(
	struct instance *instance
	)
{
/*
 * First we try to open the configuration file
 *    /etc/oncoreN
 * where N is the unit number viz 127.127.30.N.
 * If we don't find it we try
 *    /etc/ntp.oncore.N
 * and then
 *    /etc/ntp.oncore
 *
 * If we don't find any then we don't have the cable delay or PPS offset
 * and we choose MODE (4) below.
 *
 * Five Choices for MODE
 *    (0) ONCORE is preinitialized, don't do anything to change it.
 *	    nb, DON'T set 0D mode, DON'T set Delay, position...
 *    (1) NO RESET, Read Position, delays from data file, lock it in, go to 0D mode.
 *    (2) NO RESET, Read Delays from data file, do SITE SURVEY to get position,
 *		    lock this in, go to 0D mode.
 *    (3) HARD RESET, Read Position, delays from data file, lock it in, go to 0D mode.
 *    (4) HARD RESET, Read Delays from data file, do SITE SURVEY to get position,
 *		    lock this in, go to 0D mode.
 *     NB. If a POSITION is specified in the config file with mode=(2,4) [SITE SURVEY]
 *	   then this position is set as the INITIAL position of the ONCORE.
 *	   This can reduce the time to first fix.
 * -------------------------------------------------------------------------------
 * Note that an Oncore UT without a battery backup retains NO information if it is
 *   power cycled, with a Battery Backup it remembers the almanac, etc.
 * For an Oncore VP, there is an eeprom that will contain this data, along with the
 *   option of Battery Backup.
 * So a UT without Battery Backup is equivalent to doing a HARD RESET on each
 *   power cycle, since there is nowhere to store the data.
 * -------------------------------------------------------------------------------
 *
 * If we open one or the other of the files, we read it looking for
 *   MODE, LAT, LON, (HT, HTGPS, HTMSL), DELAY, OFFSET, ASSERT, CLEAR, HARDPPS,
 *   STATUS, POSN3D, POSN2D, CHAN, TRAIM
 * then initialize using method MODE.  For Mode = (1,3) all of (LAT, LON, HT) must
 *   be present or mode reverts to (2,4).
 *
 * Read input file.
 *
 *	# is comment to end of line
 *	= allowed between 1st and 2nd fields.
 *
 *	Expect to see one line with 'MODE' as first field, followed by an integer
 *	   in the range 0-4 (default = 4).
 *
 *	Expect to see two lines with 'LONG', 'LAT' followed by 1-3 fields.
 *	All numbers are floating point.
 *		DDD.ddd
 *		DDD  MMM.mmm
 *		DDD  MMM  SSS.sss
 *
 *	Expect to see one line with 'HT' as first field,
 *	   followed by 1-2 fields.  First is a number, the second is 'FT' or 'M'
 *	   for feet or meters.	HT is the height above the GPS ellipsoid.
 *	   If the receiver reports height in both GPS and MSL, then we will report
 *	   the difference GPS-MSL on the clockstats file.
 *
 *	There is an optional line, starting with DELAY, followed
 *	   by 1 or two fields.	The first is a number (a time) the second is
 *	   'MS', 'US' or 'NS' for miliseconds, microseconds or nanoseconds.
 *	    DELAY  is cable delay, typically a few tens of ns.
 *
 *	There is an optional line, starting with OFFSET, followed
 *	   by 1 or two fields.	The first is a number (a time) the second is
 *	   'MS', 'US' or 'NS' for miliseconds, microseconds or nanoseconds.
 *	   OFFSET is the offset of the PPS pulse from 0. (only fully implemented
 *		with the PPSAPI, we need to be able to tell the Kernel about this
 *		offset if the Kernel PLL is in use, but can only do this presently
 *		when using the PPSAPI interface.  If not using the Kernel PLL,
 *		then there is no problem.
 *
 *	There is an optional line, with either ASSERT or CLEAR on it, which
 *	   determine which transition of the PPS signal is used for timing by the
 *	   PPSAPI.  If neither is present, then ASSERT is assumed.
 *	   ASSERT/CLEAR can also be set with FLAG2 of the ntp.conf input.
 *	   For Flag2, ASSERT=0, and hence is default.
 *
 *	There is an optional line, with HARDPPS on it.	Including this line causes
 *	   the PPS signal to control the kernel PLL.
 *	   HARDPPS can also be set with FLAG3 of the ntp.conf input.
 *	   For Flag3, 0 is disabled, and the default.
 *
 *	There are three options that have to do with using the shared memory option.
 *	   First, to enable the option there must be a SHMEM line with a file name.
 *	   The file name is the file associated with the shared memory.
 *
 *	In shared memory, there is one 'record' for each returned variable.
 *	For the @@Ea data there are three 'records' containing position data.
 *	   There will always be data in the record corresponding to the '0D' @@Ea record,
 *	   and the user has a choice of filling the '3D' record by specifying POSN3D,
 *	   or the '2D' record by specifying POSN2D.  In either case the '2D' or '3D'
 *	   record is filled once every 15s.
 *
 *	Two additional variables that can be set are CHAN and TRAIM.  These should be
 *	   set correctly by the code examining the @@Cj record, but we bring them out here
 *	   to allow the user to override either the # of channels, or the existence of TRAIM.
 *	   CHAN expects to be followed by in integer: 6, 8, or 12. TRAIM expects to be
 *	   followed by YES or NO.
 *
 *	There is an optional line with MASK on it followed by one integer field in the
 *	   range 0 to 89. This sets the satellite mask angle and will determine the minimum
 *	   elevation angle for satellites to be tracked by the receiver. The default value
 *	   is 10 deg for the VP and 0 deg for all other receivers.
 *
 * So acceptable input would be
 *	# these are my coordinates (RWC)
 *	LON  -106 34.610
 *	LAT    35 08.999
 *	HT	1589	# could equally well say HT 5215 FT
 *	DELAY  60 ns
 */

	FILE	*fd;
	char	*cp, *cc, *ca, line[100], units[2], device[20], Msg[160], **cpp;
	char	*dirs[] = { "/etc/ntp", "/etc", 0 };
	int	i, sign, lat_flg, long_flg, ht_flg, mode, mask;
	double	f1, f2, f3;

	fd = NULL;	/* just to shutup gcc complaint */
	for (cpp=dirs; *cpp; cpp++) {
		cp = *cpp;
		sprintf(device, "%s/ntp.oncore.%d", cp, instance->unit); /* try "ntp.oncore.0 */
		if ((fd=fopen(device, "r")))
			break;
		sprintf(device, "%s/ntp.oncore%d", cp, instance->unit);  /* try "ntp.oncore0" */
		if ((fd=fopen(device, "r")))
			break;
		sprintf(device, "%s/ntp.oncore", cp);   /* and finally "ntp.oncore" */
		if ((fd=fopen(device, "r")))
			break;
	}

	if (!fd) {	/* no inputfile, default to the works ... */
		instance->init_type = 4;
		return;
	}

	mode = mask = 0;
	lat_flg = long_flg = ht_flg = 0;
	while (fgets(line, 100, fd)) {

		/* Remove comments */
		if ((cp = strchr(line, '#')))
			*cp = '\0';

		/* Remove trailing space */
		for (i = strlen(line);
		     i > 0 && isascii((int)line[i - 1]) && isspace((int)line[i - 1]);
			)
			line[--i] = '\0';

		/* Remove leading space */
		for (cc = line; *cc && isascii((int)*cc) && isspace((int)*cc); cc++)
			continue;

		/* Stop if nothing left */
		if (!*cc)
			continue;

		/* Uppercase the command and find the arg */
		for (ca = cc; *ca; ca++) {
			if (isascii((int)*ca)) {
				if (islower((int)*ca)) {
					*ca = toupper(*ca);
				} else if (isspace((int)*ca) || (*ca == '='))
					break;
			}
		}

		/* Remove space (and possible =) leading the arg */
		for (; *ca && isascii((int)*ca) && (isspace((int)*ca) || (*ca == '=')); ca++)
			continue;

		if (!strncmp(cc, "STATUS", (size_t) 6) || !strncmp(cc, "SHMEM", (size_t) 5)) {
			i = strlen(ca);
			instance->shmem_fname = (char *) malloc((unsigned) (i+1));
			strcpy(instance->shmem_fname, ca);
			continue;
		}

		/* Uppercase argument as well */
		for (cp = ca; *cp; cp++)
			if (isascii((int)*cp) && islower((int)*cp))
				*cp = toupper(*cp);

		if (!strncmp(cc, "LAT", (size_t) 3)) {
			f1 = f2 = f3 = 0;
			sscanf(ca, "%lf %lf %lf", &f1, &f2, &f3);
			sign = 1;
			if (f1 < 0) {
				f1 = -f1;
				sign = -1;
			}
			instance->ss_lat = sign*1000*(fabs(f3) + 60*(fabs(f2) + 60*f1)); /*miliseconds*/
			lat_flg++;
		} else if (!strncmp(cc, "LON", (size_t) 3)) {
			f1 = f2 = f3 = 0;
			sscanf(ca, "%lf %lf %lf", &f1, &f2, &f3);
			sign = 1;
			if (f1 < 0) {
				f1 = -f1;
				sign = -1;
			}
			instance->ss_long = sign*1000*(fabs(f3) + 60*(fabs(f2) + 60*f1)); /*miliseconds*/
			long_flg++;
		} else if (!strncmp(cc, "HT", (size_t) 2)) {
			f1 = 0;
			units[0] = '\0';
			sscanf(ca, "%lf %1s", &f1, units);
			if (units[0] == 'F')
				f1 = 0.3048 * f1;
			instance->ss_ht = 100 * f1;    /* cm */
			ht_flg++;
		} else if (!strncmp(cc, "DELAY", (size_t) 5)) {
			f1 = 0;
			units[0] = '\0';
			sscanf(ca, "%lf %1s", &f1, units);
			if (units[0] == 'N')
				;
			else if (units[0] == 'U')
				f1 = 1000 * f1;
			else if (units[0] == 'M')
				f1 = 1000000 * f1;
			else
				f1 = 1000000000 * f1;
			if (f1 < 0 || f1 > 1.e9)
				f1 = 0;
			if (f1 < 0 || f1 > 999999) {
				sprintf(Msg, "PPS Cable delay of %fns out of Range, ignored", f1);
				record_clock_stats(&(instance->peer->srcadr), Msg);
			} else
				instance->delay = f1;		/* delay in ns */
		} else if (!strncmp(cc, "OFFSET", (size_t) 6)) {
			f1 = 0;
			units[0] = '\0';
			sscanf(ca, "%lf %1s", &f1, units);
			if (units[0] == 'N')
				;
			else if (units[0] == 'U')
				f1 = 1000 * f1;
			else if (units[0] == 'M')
				f1 = 1000000 * f1;
			else
				f1 = 1000000000 * f1;
			if (f1 < 0 || f1 > 1.e9)
				f1 = 0;
			if (f1 < 0 || f1 > 999999999.) {
				sprintf(Msg, "PPS Offset of %fns out of Range, ignored", f1);
				record_clock_stats(&(instance->peer->srcadr), Msg);
			} else
				instance->offset = f1;		/* offset in ns */
		} else if (!strncmp(cc, "MODE", (size_t) 4)) {
			sscanf(ca, "%d", &mode);
			if (mode < 0 || mode > 4)
				mode = 4;
		} else if (!strncmp(cc, "ASSERT", (size_t) 6)) {
			instance->assert = 1;
		} else if (!strncmp(cc, "CLEAR", (size_t) 5)) {
			instance->assert = 0;
		} else if (!strncmp(cc, "HARDPPS", (size_t) 7)) {
			instance->hardpps = 1;
		} else if (!strncmp(cc, "POSN2D", (size_t) 6)) {
			instance->shmem_Posn = 2;
		} else if (!strncmp(cc, "POSN3D", (size_t) 6)) {
			instance->shmem_Posn = 3;
		} else if (!strncmp(cc, "CHAN", (size_t) 4)) {
			sscanf(ca, "%d", &i);
			if ((i == 6) || (i == 8) || (i == 12))
				instance->chan_in = i;
		} else if (!strncmp(cc, "TRAIM", (size_t) 5)) {
			instance->traim_in = 1; 	/* so TRAIM alone is YES */
			if (!strcmp(ca, "NO") || !strcmp(ca, "OFF"))    /* Yes/No, On/Off */
				instance->traim_in = 0;
		} else if (!strncmp(cc, "MASK", (size_t) 4)) {
			sscanf(ca, "%d", &mask);
			if (mask > -1 && mask < 90)
				instance->Ag = mask;			/* Satellite mask angle */
		}
	}
	fclose(fd);

	/*
	 *    OK, have read all of data file, and extracted the good stuff.
	 *    If lat/long/ht specified they ALL must be specified for mode = (1,3).
	 */