refclock_acts.c

网络时间协议NTP 源码 版本v4.2.0b 该源码用于linux平台下

/*
 * refclock_acts - clock driver for the NIST/USNO/PTB/NPL Computer Time
 *	Services
 */
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#if defined(REFCLOCK) && (defined(CLOCK_ACTS) || defined(CLOCK_PTBACTS))

#include "ntpd.h"
#include "ntp_io.h"
#include "ntp_unixtime.h"
#include "ntp_refclock.h"
#include "ntp_stdlib.h"
#include "ntp_control.h"

#include <stdio.h>
#include <ctype.h>
#ifdef HAVE_SYS_IOCTL_H
# include <sys/ioctl.h>
#endif /* HAVE_SYS_IOCTL_H */

/*
 * This driver supports the US (NIST, USNO) and European (PTB, NPL,
 * etc.) modem time services, as well as Spectracom GPS and WWVB
 * receivers connected via a modem. The driver periodically dials a
 * number from a telephone list, receives the timecode data and
 * calculates the local clock correction. It is designed primarily for
 * use as backup when neither a radio clock nor connectivity to Internet
 * time servers is available.
 *
 * This driver requires a modem with a Hayes-compatible command set and
 * control over the modem data terminal ready (DTR) control line. The
 * modem setup string is hard-coded in the driver and may require
 * changes for nonstandard modems or special circumstances. For reasons
 * unrelated to this driver, the data set ready (DSR) control line
 * should not be set when this driver is first started.
 *
 * The calling program is initiated by setting fudge flag1, either
 * manually or automatically. When flag1 is set, the calling program
 * dials the first number in the phone command of the configuration
 * file. If that call fails, the calling program dials the second number
 * and so on. The number is specified by the Hayes ATDT prefix followed
 * by the number itself, including the prefix and long-distance digits
 * and delay code, if necessary. The flag1 is reset and the calling
 * program terminated if (a) a valid clock update has been determined,
 * (b) no more numbers remain in the list, (c) a device fault or timeout
 * occurs or (d) fudge flag1 is reset manually.
 *
 * The driver is transparent to each of the modem time services and
 * Spectracom radios. It selects the parsing algorithm depending on the
 * message length. There is some hazard should the message be corrupted.
 * However, the data format is checked carefully and only if all checks
 * succeed is the message accepted. Corrupted lines are discarded
 * without complaint.
 *
 * Fudge controls
 *
 * flag1	force a call in manual mode
 * flag2	enable port locking (not verified)
 * flag3	no modem; port is directly connected to device
 * flag4	not used
 *
 * time1	offset adjustment (s)
 *
 * Ordinarily, the serial port is connected to a modem; however, it can
 * be connected directly to a device or another computer for testing and
 * calibration. In this case set fudge flag3 and the driver will send a
 * single character 'T' at each poll event. In principle, fudge flag2
 * enables port locking, allowing the modem to be shared when not in use
 * by this driver. At least on Solaris with the current NTP I/O
 * routines, this results only in lots of ugly error messages.
 */
/*
 * National Institute of Science and Technology (NIST)
 *
 * Phone: [phone] (Boulder, CO); [phone] (Hawaii)
 *
 * Data Format
 *
 * National Institute of Standards and Technology
 * Telephone Time Service, Generator 3B
 * Enter question mark "?" for HELP
 *                         D  L D
 *  MJD  YR MO DA H  M  S  ST S UT1 msADV        <OTM>
 * 47999 90-04-18 21:39:15 50 0 +.1 045.0 UTC(NIST) *<CR><LF>
 * ...
 *
 * MJD, DST, DUT1 and UTC are not used by this driver. The "*" or "#" is
 * the on-time markers echoed by the driver and used by NIST to measure
 * and correct for the propagation delay.
 *
 * US Naval Observatory (USNO)
 *
 * Phone: [phone] (Washington, DC); [phone] (Boulder, CO)
 *
 * Data Format (two lines, repeating at one-second intervals)
 *
 * jjjjj nnn hhmmss UTC<CR><LF>
 * *<CR><LF>
 *
 * jjjjj	modified Julian day number (not used)
 * nnn		day of year
 * hhmmss	second of day
 * *		on-time marker for previous timecode
 * ...
 *
 * USNO does not correct for the propagation delay. A fudge time1 of
 * about .06 s is advisable.
 *
 * European Services (PTB, NPL, etc.)
 *
 * PTB: [phone] (Germany)
 * NPL: 0906 851 6333 (UK only)
 *
 * Data format (see the documentation for phone numbers and formats.)
 *
 * 1995-01-23 20:58:51 MEZ  10402303260219950123195849740+40000500<CR><LF>
 *
 * Spectracom GPS and WWVB Receivers
 *
 * If a modem is connected to a Spectracom receiver, this driver will
 * call it up and retrieve the time in one of two formats. As this
 * driver does not send anything, the radio will have to either be
 * configured in continuous mode or be polled by another local driver.
 */
/*
 * Interface definitions
 */
#define	DEVICE		"/dev/acts%d" /* device name and unit */
#define	SPEED232	B9600	/* uart speed (9600 baud) */
#define	PRECISION	(-10)	/* precision assumed (about 1 ms) */
#define LOCKFILE	"/var/spool/locks/LCK..cua%d"
#define DESCRIPTION	"Automated Computer Time Service" /* WRU */
#define REFID		"NONE"	/* default reference ID */
#define MSGCNT		20	/* max message count */
#define SMAX		256	/* max clockstats line length */

/*
 * Calling program modes
 */
#define MODE_AUTO	0	/* automatic mode */
#define MODE_BACKUP	1	/* backup mode */
#define MODE_MANUAL	2	/* manual mode */

/*
 * Service identifiers.
 */
#define REFACTS		"NIST"	/* NIST reference ID */
#define LENACTS		50	/* NIST format */
#define REFUSNO		"USNO"	/* USNO reference ID */
#define LENUSNO		20	/* USNO */
#define REFPTB		"PTB\0"	/* PTB/NPL reference ID */
#define LENPTB		78	/* PTB/NPL format */
#define REFWWVB		"WWVB"	/* WWVB reference ID */
#define	LENWWVB0	22	/* WWVB format 0 */
#define	LENWWVB2	24	/* WWVB format 2 */
#define LF		0x0a	/* ASCII LF */

/*
 * Modem setup strings. These may have to be changed for some modems.
 *
 * AT	command prefix
 * B1	US answer tone
 * &C0	disable carrier detect
 * &D2	hang up and return to command mode on DTR transition
 * E0	modem command echo disabled
 * l1	set modem speaker volume to low level
 * M1	speaker enabled until carrier detect
 * Q0	return result codes
 * V1	return result codes as English words
 */
#define MODEM_SETUP	"ATB1&C0&D2E0L1M1Q0V1\r" /* modem setup */
#define MODEM_HANGUP	"ATH\r"	/* modem disconnect */

/*
 * Timeouts (all in seconds)
 */
#define SETUP		3	/* setup timeout */
#define	DTR		1	/* DTR timeout */
#define ANSWER		60	/* answer timeout */
#define CONNECT		20	/* first valid message timeout */
#define TIMECODE	30	/* all valid messages timeout */

/*
 * State machine codes
 */
#define S_IDLE		0	/* wait for poll */
#define S_OK		1	/* wait for modem setup */
#define S_DTR		2	/* wait for modem DTR */
#define S_CONNECT	3	/* wait for answer*/
#define S_FIRST		4	/* wait for first valid message */
#define S_MSG		5	/* wait for all messages */
#define S_CLOSE		6	/* wait after sending disconnect */

/*
 * Unit control structure
 */
struct actsunit {
	int	unit;		/* unit number */
	int	state;		/* the first one was Delaware */
	int	timer;		/* timeout counter */
	int	retry;		/* retry index */
	int	msgcnt;		/* count of messages received */
	l_fp	tstamp;		/* on-time timestamp */
	char	*bufptr;	/* buffer pointer */
};

/*
 * Function prototypes
 */
static	int	acts_start	P((int, struct peer *));
static	void	acts_shutdown	P((int, struct peer *));
static	void	acts_receive	P((struct recvbuf *));
static	void	acts_message	P((struct peer *));
static	void	acts_timecode	P((struct peer *, char *));
static	void	acts_poll	P((int, struct peer *));
static	void	acts_timeout	P((struct peer *));
static	void	acts_disc	P((struct peer *));
static	void	acts_timer	P((int, struct peer *));

/*
 * Transfer vector (conditional structure name)
 */
struct	refclock refclock_acts = {
	acts_start,		/* start up driver */
	acts_shutdown,		/* shut down driver */
	acts_poll,		/* transmit poll message */
	noentry,		/* not used */
	noentry,		/* not used */
	noentry,		/* not used */
	acts_timer		/* housekeeping timer */
};

struct	refclock refclock_ptb;

/*
 * Initialize data for processing
 */
static int
acts_start (
	int	unit,
	struct peer *peer
	)
{
	struct actsunit *up;
	struct refclockproc *pp;

	/*
	 * Allocate and initialize unit structure
	 */
	up = emalloc(sizeof(struct actsunit));
	if (up == NULL)
		return (0);

	memset(up, 0, sizeof(struct actsunit));
	up->unit = unit;
	pp = peer->procptr;
	pp->unitptr = (caddr_t)up;
	pp->io.clock_recv = acts_receive;
	pp->io.srcclock = (caddr_t)peer;
	pp->io.datalen = 0;

	/*
	 * Initialize miscellaneous variables
	 */
	peer->precision = PRECISION;
	pp->clockdesc = DESCRIPTION;
	memcpy((char *)&pp->refid, REFID, 4);
	peer->sstclktype = CTL_SST_TS_TELEPHONE;
	peer->flags &= ~FLAG_FIXPOLL;
	up->bufptr = pp->a_lastcode;
	return (1);
}


/*
 * acts_shutdown - shut down the clock
 */
static void
acts_shutdown (
	int	unit,
	struct peer *peer
	)
{
	struct actsunit *up;
	struct refclockproc *pp;

	/*
	 * Warning: do this only when a call is not in progress.
	 */
	pp = peer->procptr;
	up = (struct actsunit *)pp->unitptr;
	free(up);
}


/*
 * acts_receive - receive data from the serial interface
 */
static void
acts_receive (
	struct recvbuf *rbufp
	)
{
	struct actsunit *up;
	struct refclockproc *pp;
	struct peer *peer;
	char	tbuf[BMAX];
	char	*tptr;

	/*
	 * Initialize pointers and read the timecode and timestamp. Note
	 * we are in raw mode and victim of whatever the terminal
	 * interface kicks up; so, we have to reassemble messages from
	 * arbitrary fragments. Capture the timecode at the beginning of
	 * the message and at the '*' and '#' on-time characters.
	 */
	peer = (struct peer *)rbufp->recv_srcclock;
	pp = peer->procptr;
	up = (struct actsunit *)pp->unitptr;
	pp->lencode = refclock_gtraw(rbufp, tbuf, BMAX - (up->bufptr -
	    pp->a_lastcode), &pp->lastrec);
	for (tptr = tbuf; *tptr != '\0'; tptr++) {
		if (*tptr == LF) {
			if (up->bufptr == pp->a_lastcode) {
				up->tstamp = pp->lastrec;
				continue;

			} else {
				*up->bufptr = '\0';
				acts_message(peer);
				up->bufptr = pp->a_lastcode;
			}
		} else {
			*up->bufptr++ = *tptr;
			if (*tptr == '*' || *tptr == '#') {
				up->tstamp = pp->lastrec;
				write(pp->io.fd, tptr, 1);
			}
		}
	}
}


/*
 * acts_message - process message
 */
void
acts_message(
	struct peer *peer
	)
{
	struct actsunit *up;
	struct refclockproc *pp;
	int	dtr = TIOCM_DTR;
	char	tbuf[SMAX];
#ifdef DEBUG
	u_int	modem;
#endif

	/*
	 * What to do depends on the state and the first token in the
	 * message. A NO token sends the message to the clockstats.
	 */
	pp = peer->procptr;
	up = (struct actsunit *)pp->unitptr;
#ifdef DEBUG
	ioctl(pp->io.fd, TIOCMGET, (char *)&modem);
	sprintf(tbuf, "acts: %04x (%d %d) %d %s", modem, up->state,
	    up->timer, strlen(pp->a_lastcode), pp->a_lastcode);
	if (debug)
		printf("%s\n", tbuf);
#endif
	strncpy(tbuf, pp->a_lastcode, SMAX);
	strtok(tbuf, " ");
	if (strcmp(tbuf, "NO") == 0)
		record_clock_stats(&peer->srcadr, pp->a_lastcode);
	switch(up->state) {

	/*
	 * We are waiting for the OK response to the modem setup
	 * command. When this happens, raise DTR and dial the number
	 * followed by \r.
	 */
	case S_OK:
		if (strcmp(tbuf, "OK") != 0) {
			msyslog(LOG_ERR, "acts: setup error %s",
			    pp->a_lastcode);
			acts_disc(peer);
			return;
		}
		ioctl(pp->io.fd, TIOCMBIS, (char *)&dtr);
		up->state = S_DTR;
		up->timer = DTR;
		return;

	/*
	 * We are waiting for the call to be answered. All we care about
	 * here is token CONNECT. Send the message to the clockstats.
	 */
	case S_CONNECT:
		record_clock_stats(&peer->srcadr, pp->a_lastcode);
		if (strcmp(tbuf, "CONNECT") != 0) {
			acts_disc(peer);
			return;
		}
		up->state = S_FIRST;
		up->timer = CONNECT;
		return;

	/*
	 * We are waiting for a timecode. Pass it to the parser.
	 */
	case S_FIRST:
	case S_MSG:
		acts_timecode(peer, pp->a_lastcode);
		break;
	}
}

/*
 * acts_timecode - identify the service and parse the timecode message
 */
void
acts_timecode(
	struct peer *peer,	/* peer structure pointer */
	char	*str		/* timecode string */
	)
{
	struct actsunit *up;
	struct refclockproc *pp;
	int	day;		/* day of the month */
	int	month;		/* month of the year */
	u_long	mjd;		/* Modified Julian Day */
	double	dut1;		/* DUT adjustment */

	u_int	dst;		/* ACTS daylight/standard time */
	u_int	leap;		/* ACTS leap indicator */
	double	msADV;		/* ACTS transmit advance (ms) */
	char	utc[10];	/* ACTS timescale */
	char	flag;		/* ACTS on-time character (* or #) */

	char	synchar;	/* WWVB synchronized indicator */
	char	qualchar;	/* WWVB quality indicator */
	char	leapchar;	/* WWVB leap indicator */
	char	dstchar;	/* WWVB daylight/savings indicator */
	int	tz;		/* WWVB timezone */

	u_int	leapmonth;	/* PTB/NPL month of leap */
	char	leapdir;	/* PTB/NPL leap direction */

	/*
	 * The parser selects the modem format based on the message
	 * length. Since the data are checked carefully, occasional
	 * errors due noise are forgivable.
	 */
	pp = peer->procptr;
	up = (struct actsunit *)pp->unitptr;
	pp->nsec = 0;
	switch(strlen(str)) {

	/*
	 * For USNO format on-time character '*', which is on a line by
	 * itself. Be sure a timecode has been received.