ntp_refclock.c

网络时间协议NTP 源码 版本v4.2.0b 该源码用于linux平台下

		peer->timereachable = current_time;
	}
	peer->reach |= 1;
	peer->reftime = pp->lastref;
	peer->org = pp->lastrec;
	peer->rootdispersion = pp->disp;
	get_systime(&peer->rec);
	if (!refclock_sample(pp))
		return;

	clock_filter(peer, pp->offset, 0., pp->jitter);
	record_peer_stats(&peer->srcadr, ctlpeerstatus(peer),
	    peer->offset, peer->delay, clock_phi * (current_time -
	    peer->epoch), peer->jitter);
	if (cal_enable && last_offset < MINDISPERSE) {
#ifdef KERNEL_PLL
		if (peer != sys_peer || pll_status & STA_PPSTIME)
#else
		if (peer != sys_peer)
#endif /* KERNEL_PLL */
			pp->fudgetime1 -= pp->offset * FUDGEFAC;
		else
			pp->fudgetime1 -= pp->fudgetime1 * FUDGEFAC;
	}
}


/*
 * refclock_gtlin - groom next input line and extract timestamp
 *
 * This routine processes the timecode received from the clock and
 * strips the parity bit and control characters. It returns the number
 * of characters in the line followed by a NULL character ('\0'), which
 * is not included in the count. In case of an empty line, the previous
 * line is preserved.
 */
int
refclock_gtlin(
	struct recvbuf *rbufp,	/* receive buffer pointer */
	char	*lineptr,	/* current line pointer */
	int	bmax,		/* remaining characters in line */
	l_fp	*tsptr		/* pointer to timestamp returned */
	)
{
	char	s[BMAX];
	char	*dpt, *dpend, *dp;

	dpt = s;
	dpend = s + refclock_gtraw(rbufp, s, BMAX - 1, tsptr);
	if (dpend - dpt > bmax - 1)
		dpend = dpt + bmax - 1;
	for (dp = lineptr; dpt < dpend; dpt++) {
		char	c;

		c = *dpt & 0x7f;
		if (c >= 0x20 && c < 0x7f)
			*dp++ = c;
	}
	if (dp == lineptr)
		return (0);

	*dp = '\0';
	return (dp - lineptr);
}


/*
 * refclock_gtraw - get next line/chunk of data
 *
 * This routine returns the raw data received from the clock in both
 * canonical or raw modes. The terminal interface routines map CR to LF.
 * In canonical mode this results in two lines, one containing data
 * followed by LF and another containing only LF. In raw mode the
 * interface routines can deliver arbitraty chunks of data from one
 * character to a maximum specified by the calling routine. In either
 * mode the routine returns the number of characters in the line
 * followed by a NULL character ('\0'), which is not included in the
 * count.
 *
 * If a timestamp is present in the timecode, as produced by the tty_clk
 * STREAMS module, it returns that as the timestamp; otherwise, it
 * returns the buffer timestamp.
 */
int
refclock_gtraw(
	struct recvbuf *rbufp,	/* receive buffer pointer */
	char	*lineptr,	/* current line pointer */
	int	bmax,		/* remaining characters in line */
	l_fp	*tsptr		/* pointer to timestamp returned */
	)
{
	char	*dpt, *dpend, *dp;
	l_fp	trtmp, tstmp;
	int	i;

	/*
	 * Check for the presence of a timestamp left by the tty_clock
	 * module and, if present, use that instead of the buffer
	 * timestamp captured by the I/O routines. We recognize a
	 * timestamp by noting its value is earlier than the buffer
	 * timestamp, but not more than one second earlier.
	 */
	dpt = (char *)rbufp->recv_buffer;
	dpend = dpt + rbufp->recv_length;
	trtmp = rbufp->recv_time;
	if (dpend >= dpt + 8) {
		if (buftvtots(dpend - 8, &tstmp)) {
			L_SUB(&trtmp, &tstmp);
			if (trtmp.l_ui == 0) {
#ifdef DEBUG
				if (debug > 1) {
					printf(
					    "refclock_gtlin: fd %d ldisc %s",
					    rbufp->fd, lfptoa(&trtmp,
					    6));
					get_systime(&trtmp);
					L_SUB(&trtmp, &tstmp);
					printf(" sigio %s\n",
					    lfptoa(&trtmp, 6));
				}
#endif
				dpend -= 8;
				trtmp = tstmp;
			} else
				trtmp = rbufp->recv_time;
		}
	}

	/*
	 * Copy the raw buffer to the user string. The string is padded
	 * with a NULL, which is not included in the character count.
	 */
	if (dpend - dpt > bmax - 1)
		dpend = dpt + bmax - 1;
	for (dp = lineptr; dpt < dpend; dpt++)
		*dp++ = *dpt;
	*dp = '\0';
	i = dp - lineptr;
#ifdef DEBUG
	if (debug > 1)
		printf("refclock_gtraw: fd %d time %s timecode %d %s\n",
		    rbufp->fd, ulfptoa(&trtmp, 6), i, lineptr);
#endif
	*tsptr = trtmp;
	return (i);
}


/*
 * The following code does not apply to WINNT & VMS ...
 */
#if !defined SYS_VXWORKS && !defined SYS_WINNT
#if defined(HAVE_TERMIOS) || defined(HAVE_SYSV_TTYS) || defined(HAVE_BSD_TTYS)

/*
 * refclock_open - open serial port for reference clock
 *
 * This routine opens a serial port for I/O and sets default options. It
 * returns the file descriptor if success and zero if failure.
 */
int
refclock_open(
	char	*dev,		/* device name pointer */
	u_int	speed,		/* serial port speed (code) */
	u_int	lflags		/* line discipline flags */
	)
{
	int	fd;
	int	omode;

	/*
	 * Open serial port and set default options
	 */
	omode = O_RDWR;
#ifdef O_NONBLOCK
	omode |= O_NONBLOCK;
#endif
#ifdef O_NOCTTY
	omode |= O_NOCTTY;
#endif

	fd = open(dev, omode, 0777);
	if (fd < 0) {
		msyslog(LOG_ERR, "refclock_open %s: %m", dev);
		return (0);
	}
	if (!refclock_setup(fd, speed, lflags)) {
		close(fd);
		return (0);
	}
	if (!refclock_ioctl(fd, lflags)) {
		close(fd);
		return (0);
	}
	return (fd);
}

/*
 * refclock_setup - initialize terminal interface structure
 */
int
refclock_setup(
	int	fd,		/* file descriptor */
	u_int	speed,		/* serial port speed (code) */
	u_int	lflags		/* line discipline flags */
	)
{
	int	i;
	TTY	ttyb, *ttyp;
#ifdef PPS
	fdpps = fd;		/* ppsclock legacy */
#endif /* PPS */

	/*
	 * By default, the serial line port is initialized in canonical
	 * (line-oriented) mode at specified line speed, 8 bits and no
	 * parity. LF ends the line and CR is mapped to LF. The break,
	 * erase and kill functions are disabled. There is a different
	 * section for each terminal interface, as selected at compile
	 * time. The flag bits can be used to set raw mode and echo.
	 */
	ttyp = &ttyb;
#ifdef HAVE_TERMIOS

	/*
	 * POSIX serial line parameters (termios interface)
	 */
	if (tcgetattr(fd, ttyp) < 0) {
		msyslog(LOG_ERR,
			"refclock_setup fd %d tcgetattr: %m", fd);
		return (0);
	}

	/*
	 * Set canonical mode and local connection; set specified speed,
	 * 8 bits and no parity; map CR to NL; ignore break.
	 */
	if (speed) {
		u_int	ltemp = 0;

		ttyp->c_iflag = IGNBRK | IGNPAR | ICRNL;
		ttyp->c_oflag = 0;
		ttyp->c_cflag = CS8 | CLOCAL | CREAD;
		if (lflags & LDISC_7O1) {
			/* HP Z3801A needs 7-bit, odd parity */
  			ttyp->c_cflag = CS7 | PARENB | PARODD | CLOCAL | CREAD;
		}
		cfsetispeed(&ttyb, speed);
		cfsetospeed(&ttyb, speed);
		for (i = 0; i < NCCS; ++i)
			ttyp->c_cc[i] = '\0';

#if defined(TIOCMGET) && !defined(SCO5_CLOCK)

		/*
		 * If we have modem control, check to see if modem leads
		 * are active; if so, set remote connection. This is
		 * necessary for the kernel pps mods to work.
		 */
		if (ioctl(fd, TIOCMGET, (char *)&ltemp) < 0)
			msyslog(LOG_ERR,
			    "refclock_setup fd %d TIOCMGET: %m", fd);
#ifdef DEBUG
		if (debug)
			printf("refclock_setup fd %d modem status: 0x%x\n",
			    fd, ltemp);
#endif
		if (ltemp & TIOCM_DSR && lflags & LDISC_REMOTE)
			ttyp->c_cflag &= ~CLOCAL;
#endif /* TIOCMGET */
	}

	/*
	 * Set raw and echo modes. These can be changed on-fly.
	 */
	ttyp->c_lflag = ICANON;
	if (lflags & LDISC_RAW) {
		ttyp->c_lflag = 0;
		ttyp->c_cc[VMIN] = 1;
	}
	if (lflags & LDISC_ECHO)
		ttyp->c_lflag |= ECHO;
	if (tcsetattr(fd, TCSANOW, ttyp) < 0) {
		msyslog(LOG_ERR,
		    "refclock_setup fd %d TCSANOW: %m", fd);
		return (0);
	}
#endif /* HAVE_TERMIOS */

#ifdef HAVE_SYSV_TTYS

	/*
	 * System V serial line parameters (termio interface)
	 *
	 */
	if (ioctl(fd, TCGETA, ttyp) < 0) {
		msyslog(LOG_ERR,
		    "refclock_setup fd %d TCGETA: %m", fd);
		return (0);
	}

	/*
	 * Set canonical mode and local connection; set specified speed,
	 * 8 bits and no parity; map CR to NL; ignore break.
	 */
	if (speed) {
		u_int	ltemp = 0;

		ttyp->c_iflag = IGNBRK | IGNPAR | ICRNL;
		ttyp->c_oflag = 0;
		ttyp->c_cflag = speed | CS8 | CLOCAL | CREAD;
		for (i = 0; i < NCCS; ++i)
			ttyp->c_cc[i] = '\0';

#if defined(TIOCMGET) && !defined(SCO5_CLOCK)

		/*
		 * If we have modem control, check to see if modem leads
		 * are active; if so, set remote connection. This is
		 * necessary for the kernel pps mods to work.
		 */
		if (ioctl(fd, TIOCMGET, (char *)&ltemp) < 0)
			msyslog(LOG_ERR,
			    "refclock_setup fd %d TIOCMGET: %m", fd);
#ifdef DEBUG
		if (debug)
			printf("refclock_setup fd %d modem status: %x\n",
			    fd, ltemp);
#endif
		if (ltemp & TIOCM_DSR)
			ttyp->c_cflag &= ~CLOCAL;
#endif /* TIOCMGET */
	}

	/*
	 * Set raw and echo modes. These can be changed on-fly.
	 */
	ttyp->c_lflag = ICANON;
	if (lflags & LDISC_RAW) {
		ttyp->c_lflag = 0;
		ttyp->c_cc[VMIN] = 1;
	}
	if (ioctl(fd, TCSETA, ttyp) < 0) {
		msyslog(LOG_ERR,
		    "refclock_setup fd %d TCSETA: %m", fd);
		return (0);
	}
#endif /* HAVE_SYSV_TTYS */

#ifdef HAVE_BSD_TTYS

	/*
	 * 4.3bsd serial line parameters (sgttyb interface)
	 */
	if (ioctl(fd, TIOCGETP, (char *)ttyp) < 0) {
		msyslog(LOG_ERR,
		    "refclock_setup fd %d TIOCGETP: %m", fd);
		return (0);
	}
	if (speed)
		ttyp->sg_ispeed = ttyp->sg_ospeed = speed;
	ttyp->sg_flags = EVENP | ODDP | CRMOD;
	if (ioctl(fd, TIOCSETP, (char *)ttyp) < 0) {
		msyslog(LOG_ERR,
		    "refclock_setup TIOCSETP: %m");
		return (0);
	}
#endif /* HAVE_BSD_TTYS */
	return(1);
}
#endif /* HAVE_TERMIOS || HAVE_SYSV_TTYS || HAVE_BSD_TTYS */
#endif /* SYS_VXWORKS SYS_WINNT */


/*
 * refclock_ioctl - set serial port control functions
 *
 * This routine attempts to hide the internal, system-specific details
 * of serial ports. It can handle POSIX (termios), SYSV (termio) and BSD
 * (sgtty) interfaces with varying degrees of success. The routine sets
 * up optional features such as tty_clk. The routine returns 1 if
 * success and 0 if failure.
 */
int
refclock_ioctl(
	int	fd, 		/* file descriptor */
	u_int	lflags		/* line discipline flags */
	)
{
	/*
	 * simply return 1 if no UNIX line discipline is supported
	 */
#if !defined SYS_VXWORKS && !defined SYS_WINNT
#if defined(HAVE_TERMIOS) || defined(HAVE_SYSV_TTYS) || defined(HAVE_BSD_TTYS)

#ifdef DEBUG
	if (debug)
		printf("refclock_ioctl: fd %d flags 0x%x\n", fd,
		    lflags);
#endif
#ifdef TTYCLK

	/*
	 * The TTYCLK option provides timestamping at the driver level.
	 * It requires the tty_clk streams module and System V STREAMS
	 * support. If not available, don't complain.
	 */
	if (lflags & (LDISC_CLK | LDISC_CLKPPS | LDISC_ACTS)) {
		int rval = 0;

		if (ioctl(fd, I_PUSH, "clk") < 0) {
			msyslog(LOG_NOTICE,
			    "refclock_ioctl fd %d I_PUSH: %m", fd);
			return (0);
#ifdef CLK_SETSTR
		} else {
			char *str;

			if (lflags & LDISC_CLKPPS)
				str = "\377";
			else if (lflags & LDISC_ACTS)
				str = "*";
			else
				str = "\n";
			if (ioctl(fd, CLK_SETSTR, str) < 0) {
				msyslog(LOG_ERR,
				    "refclock_ioctl fd %d CLK_SETSTR: %m", fd);
				return (0);
			}
#endif /*CLK_SETSTR */
		}
	}
#endif /* TTYCLK */
#endif /* HAVE_TERMIOS || HAVE_SYSV_TTYS || HAVE_BSD_TTYS */
#endif /* SYS_VXWORKS SYS_WINNT */
	return (1);
}


/*
 * refclock_control - set and/or return clock values
 *
 * This routine is used mainly for debugging. It returns designated
 * values from the interface structure that can be displayed using
 * ntpdc and the clockstat command. It can also be used to initialize
 * configuration variables, such as fudgetimes, fudgevalues, reference
 * ID and stratum.
 */
void
refclock_control(
	struct sockaddr_storage *srcadr,
	struct refclockstat *in,
	struct refclockstat *out
	)
{
	struct peer *peer;
	struct refclockproc *pp;
	u_char clktype;
	int unit;

	/*
	 * Check for valid address and running peer
	 */
	if (srcadr->ss_family != AF_INET)
		return;

	if (!ISREFCLOCKADR(srcadr))
		return;

	clktype = (u_char)REFCLOCKTYPE(srcadr);
	unit = REFCLOCKUNIT(srcadr);
	if (clktype >= num_refclock_conf || unit >= MAXUNIT)
		return;

	peer = typeunit[clktype][unit];
	if (peer == NULL)
		return;

	if (peer->procptr == NULL)
		return;

	pp = peer->procptr;

	/*
	 * Initialize requested data
	 */
	if (in != 0) {
		if (in->haveflags & CLK_HAVETIME1)
			pp->fudgetime1 = in->fudgetime1;
		if (in->haveflags & CLK_HAVETIME2)
			pp->fudgetime2 = in->fudgetime2;
		if (in->haveflags & CLK_HAVEVAL1)
			peer->stratum = pp->stratum = (u_char)in->fudgeval1;
		if (in->haveflags & CLK_HAVEVAL2)
			peer->refid = pp->refid = in->fudgeval2;
		if (in->haveflags & CLK_HAVEFLAG1) {
			pp->sloppyclockflag &= ~CLK_FLAG1;
			pp->sloppyclockflag |= in->flags & CLK_FLAG1;
		}
		if (in->haveflags & CLK_HAVEFLAG2) {
			pp->sloppyclockflag &= ~CLK_FLAG2;
			pp->sloppyclockflag |= in->flags & CLK_FLAG2;
		}
		if (in->haveflags & CLK_HAVEFLAG3) {
			pp->sloppyclockflag &= ~CLK_FLAG3;
			pp->sloppyclockflag |= in->flags & CLK_FLAG3;
		}
		if (in->haveflags & CLK_HAVEFLAG4) {
			pp->sloppyclockflag &= ~CLK_FLAG4;
			pp->sloppyclockflag |= in->flags & CLK_FLAG4;
		}
	}

	/*
	 * Readback requested data
	 */
	if (out != 0) {
		out->haveflags = CLK_HAVETIME1 | CLK_HAVEVAL1 |
			CLK_HAVEVAL2 | CLK_HAVEFLAG4;
		out->fudgetime1 = pp->fudgetime1;
		out->fudgetime2 = pp->fudgetime2;
		out->fudgeval1 = pp->stratum;
		out->fudgeval2 = pp->refid;
		out->flags = (u_char) pp->sloppyclockflag;

		out->timereset = current_time - pp->timestarted;
		out->polls = pp->polls;
		out->noresponse = pp->noreply;
		out->badformat = pp->badformat;
		out->baddata = pp->baddata;

		out->lastevent = pp->lastevent;
		out->currentstatus = pp->currentstatus;
		out->type = pp->type;
		out->clockdesc = pp->clockdesc;
		out->lencode = pp->lencode;
		out->p_lastcode = pp->a_lastcode;
	}

	/*
	 * Give the stuff to the clock
	 */
	if (refclock_conf[clktype]->clock_control != noentry)
		(refclock_conf[clktype]->clock_control)(unit, in, out, peer);
}


/*
 * refclock_buginfo - return debugging info
 *
 * This routine is used mainly for debugging. It returns designated
 * values from the interface structure that can be displayed using
 * ntpdc and the clkbug command.
 */
void
refclock_buginfo(
	struct sockaddr_storage *srcadr, /* clock address */
	struct refclockbug *bug /* output structure */
	)
{
	struct peer *peer;
	struct refclockproc *pp;
	u_char clktype;
	int unit;
	int i;

	/*
	 * Check for valid address and peer structure
	 */
	if (srcadr->ss_family != AF_INET)
		return;

	if (!ISREFCLOCKADR(srcadr))
		return;

	clktype = (u_char) REFCLOCKTYPE(srcadr);
	unit = REFCLOCKUNIT(srcadr);
	if (clktype >= num_refclock_conf || unit >= MAXUNIT)
		return;

	peer = typeunit[clktype][unit];
	if (peer == NULL)
		return;

	pp = peer->procptr;

	/*
	 * Copy structure values
	 */
	bug->nvalues = 8;
	bug->svalues = 0x0000003f;
	bug->values[0] = pp->year;
	bug->values[1] = pp->day;
	bug->values[2] = pp->hour;
	bug->values[3] = pp->minute;
	bug->values[4] = pp->second;
	bug->values[5] = pp->nsec;
	bug->values[6] = pp->yearstart;
	bug->values[7] = pp->coderecv;
	bug->stimes = 0xfffffffc;
	bug->times[0] = pp->lastref;
	bug->times[1] = pp->lastrec;
	for (i = 2; i < (int)bug->ntimes; i++)
		DTOLFP(pp->filter[i - 2], &bug->times[i]);

	/*
	 * Give the stuff to the clock
	 */
	if (refclock_conf[clktype]->clock_buginfo != noentry)
		(refclock_conf[clktype]->clock_buginfo)(unit, bug, peer);
}

#endif /* REFCLOCK */