xref: /freebsd/contrib/ntp/ntpd/refclock_dumbclock.c (revision 63a938566d524836885917d95bd491aa4400b181)
1 /*
2  * refclock_dumbclock - clock driver for a unknown time distribution system
3  * that only provides hh:mm:ss (in local time, yet!).
4  */
5 
6 /*
7  * Must interpolate back to local time.  Very annoying.
8  */
9 #define GET_LOCALTIME
10 
11 #ifdef HAVE_CONFIG_H
12 #include <config.h>
13 #endif
14 
15 #if defined(REFCLOCK) && defined(CLOCK_DUMBCLOCK)
16 
17 #include "ntpd.h"
18 #include "ntp_io.h"
19 #include "ntp_refclock.h"
20 #include "ntp_calendar.h"
21 #include "ntp_stdlib.h"
22 
23 #include <stdio.h>
24 #include <ctype.h>
25 
26 #ifdef SYS_WINNT
27 extern int async_write(int, const void *, unsigned int);
28 #undef write
29 #define write(fd, data, octets)	async_write(fd, data, octets)
30 #endif
31 
32 /*
33  * This driver supports a generic dumb clock that only outputs hh:mm:ss,
34  * in local time, no less.
35  *
36  * Input format:
37  *
38  *	hh:mm:ss   <cr>
39  *
40  * hh:mm:ss -- what you'd expect, with a 24 hour clock.  (Heck, that's the only
41  * way it could get stupider.)  We take time on the <cr>.
42  *
43  * The original source of this module was the WWVB module.
44  */
45 
46 /*
47  * Interface definitions
48  */
49 #define	DEVICE		"/dev/dumbclock%d" /* device name and unit */
50 #define	SPEED232	B9600	/* uart speed (9600 baud) */
51 #define	PRECISION	(-13)	/* precision assumed (about 100 us) */
52 #define	REFID		"dumbclock"	/* reference ID */
53 #define	DESCRIPTION	"Dumb clock" /* WRU */
54 
55 
56 /*
57  * Insanity check.  Since the time is local, we need to make sure that during midnight
58  * transitions, we can convert back to Unix time.  If the conversion results in some number
59  * worse than this number of seconds away, assume the next day and retry.
60  */
61 #define INSANE_SECONDS 3600
62 
63 /*
64  * Dumb clock control structure
65  */
66 struct dumbclock_unit {
67 	u_char	  tcswitch;	/* timecode switch */
68 	l_fp	  laststamp;	/* last receive timestamp */
69 	u_char	  lasthour;	/* last hour (for monitor) */
70 	u_char	  linect;	/* count ignored lines (for monitor */
71 	struct tm ymd;		/* struct tm for y/m/d only */
72 };
73 
74 /*
75  * Function prototypes
76  */
77 static	int	dumbclock_start		(int, struct peer *);
78 static	void	dumbclock_shutdown	(int, struct peer *);
79 static	void	dumbclock_receive	(struct recvbuf *);
80 #if 0
81 static	void	dumbclock_poll		(int, struct peer *);
82 #endif
83 
84 /*
85  * Transfer vector
86  */
87 struct	refclock refclock_dumbclock = {
88 	dumbclock_start,		     /* start up driver */
89 	dumbclock_shutdown,		     /* shut down driver */
90 	noentry,			     /* poll the driver -- a nice fabrication */
91 	noentry,			     /* not used */
92 	noentry,			     /* not used */
93 	noentry,			     /* not used */
94 	NOFLAGS				     /* not used */
95 };
96 
97 
98 /*
99  * dumbclock_start - open the devices and initialize data for processing
100  */
101 static int
102 dumbclock_start(
103 	int unit,
104 	struct peer *peer
105 	)
106 {
107 	register struct dumbclock_unit *up;
108 	struct refclockproc *pp;
109 	int fd;
110 	char device[20];
111 	struct tm *tm_time_p;
112 	time_t     now;
113 
114 	/*
115 	 * Open serial port. Don't bother with CLK line discipline, since
116 	 * it's not available.
117 	 */
118 	snprintf(device, sizeof(device), DEVICE, unit);
119 #ifdef DEBUG
120 	if (debug)
121 		printf ("starting Dumbclock with device %s\n",device);
122 #endif
123 	fd = refclock_open(device, SPEED232, 0);
124 	if (fd <= 0)
125 		return (0);
126 
127 	/*
128 	 * Allocate and initialize unit structure
129 	 */
130 	up = emalloc_zero(sizeof(*up));
131 	pp = peer->procptr;
132 	pp->unitptr = up;
133 	pp->io.clock_recv = dumbclock_receive;
134 	pp->io.srcclock = peer;
135 	pp->io.datalen = 0;
136 	pp->io.fd = fd;
137 	if (!io_addclock(&pp->io)) {
138 		close(fd);
139 		pp->io.fd = -1;
140 		free(up);
141 		pp->unitptr = NULL;
142 		return (0);
143 	}
144 
145 
146 	time(&now);
147 #ifdef GET_LOCALTIME
148 	tm_time_p = localtime(&now);
149 #else
150 	tm_time_p = gmtime(&now);
151 #endif
152 	if (tm_time_p)
153 		up->ymd = *tm_time_p;
154 	else
155 		return 0;
156 
157 	/*
158 	 * Initialize miscellaneous variables
159 	 */
160 	peer->precision = PRECISION;
161 	pp->clockdesc = DESCRIPTION;
162 	memcpy((char *)&pp->refid, REFID, 4);
163 	return (1);
164 }
165 
166 
167 /*
168  * dumbclock_shutdown - shut down the clock
169  */
170 static void
171 dumbclock_shutdown(
172 	int unit,
173 	struct peer *peer
174 	)
175 {
176 	register struct dumbclock_unit *up;
177 	struct refclockproc *pp;
178 
179 	pp = peer->procptr;
180 	up = pp->unitptr;
181 	if (-1 != pp->io.fd)
182 		io_closeclock(&pp->io);
183 	if (NULL != up)
184 		free(up);
185 }
186 
187 
188 /*
189  * dumbclock_receive - receive data from the serial interface
190  */
191 static void
192 dumbclock_receive(
193 	struct recvbuf *rbufp
194 	)
195 {
196 	struct dumbclock_unit *up;
197 	struct refclockproc *pp;
198 	struct peer *peer;
199 
200 	l_fp	trtmp;		/* arrival timestamp */
201 	int	hours;		/* hour-of-day */
202 	int	minutes;	/* minutes-past-the-hour */
203 	int	seconds;	/* seconds */
204 	int	temp;		/* int temp */
205 	int	got_good;	/* got a good time flag */
206 
207 	/*
208 	 * Initialize pointers and read the timecode and timestamp
209 	 */
210 	peer = rbufp->recv_peer;
211 	pp = peer->procptr;
212 	up = pp->unitptr;
213 	temp = refclock_gtlin(rbufp, pp->a_lastcode, BMAX, &trtmp);
214 
215 	if (temp == 0) {
216 		if (up->tcswitch == 0) {
217 			up->tcswitch = 1;
218 			up->laststamp = trtmp;
219 		} else
220 			up->tcswitch = 0;
221 		return;
222 	}
223 	pp->lencode = (u_short)temp;
224 	pp->lastrec = up->laststamp;
225 	up->laststamp = trtmp;
226 	up->tcswitch = 1;
227 
228 #ifdef DEBUG
229 	if (debug)
230 		printf("dumbclock: timecode %d %s\n",
231 		       pp->lencode, pp->a_lastcode);
232 #endif
233 
234 	/*
235 	 * We get down to business. Check the timecode format...
236 	 */
237 	got_good=0;
238 	if (sscanf(pp->a_lastcode,"%02d:%02d:%02d",
239 		   &hours,&minutes,&seconds) == 3)
240 	{
241 	    struct tm *gmtp;
242 	    struct tm *lt_p;
243 	    time_t     asserted_time;	     /* the SPM time based on the composite time+date */
244 	    struct tm  asserted_tm;	     /* the struct tm of the same */
245 	    int        adjyear;
246 	    int        adjmon;
247 	    time_t     reality_delta;
248 	    time_t     now;
249 
250 
251 	    /*
252 	     * Convert to GMT for sites that distribute localtime.  This
253 	     * means we have to figure out what day it is.  Easier said
254 	     * than done...
255 	     */
256 
257 	    memset(&asserted_tm, 0, sizeof(asserted_tm));
258 
259 	    asserted_tm.tm_year  = up->ymd.tm_year;
260 	    asserted_tm.tm_mon   = up->ymd.tm_mon;
261 	    asserted_tm.tm_mday  = up->ymd.tm_mday;
262 	    asserted_tm.tm_hour  = hours;
263 	    asserted_tm.tm_min   = minutes;
264 	    asserted_tm.tm_sec   = seconds;
265 	    asserted_tm.tm_isdst = -1;
266 
267 #ifdef GET_LOCALTIME
268 	    asserted_time = mktime (&asserted_tm);
269 	    time(&now);
270 #else
271 #include "GMT unsupported for dumbclock!"
272 #endif
273 	    reality_delta = asserted_time - now;
274 
275 	    /*
276 	     * We assume that if the time is grossly wrong, it's because we got the
277 	     * year/month/day wrong.
278 	     */
279 	    if (reality_delta > INSANE_SECONDS)
280 	    {
281 		asserted_time -= SECSPERDAY; /* local clock behind real time */
282 	    }
283 	    else if (-reality_delta > INSANE_SECONDS)
284 	    {
285 		asserted_time += SECSPERDAY; /* local clock ahead of real time */
286 	    }
287 	    lt_p = localtime(&asserted_time);
288 	    if (lt_p)
289 	    {
290 		up->ymd = *lt_p;
291 	    }
292 	    else
293 	    {
294 		refclock_report (peer, CEVNT_FAULT);
295 		return;
296 	    }
297 
298 	    if ((gmtp = gmtime (&asserted_time)) == NULL)
299 	    {
300 		refclock_report (peer, CEVNT_FAULT);
301 		return;
302 	    }
303 	    adjyear = gmtp->tm_year+1900;
304 	    adjmon  = gmtp->tm_mon+1;
305 	    pp->day = ymd2yd (adjyear, adjmon, gmtp->tm_mday);
306 	    pp->hour   = gmtp->tm_hour;
307 	    pp->minute = gmtp->tm_min;
308 	    pp->second = gmtp->tm_sec;
309 #ifdef DEBUG
310 	    if (debug)
311 		printf ("time is %04d/%02d/%02d %02d:%02d:%02d UTC\n",
312 			adjyear,adjmon,gmtp->tm_mday,pp->hour,pp->minute,
313 			pp->second);
314 #endif
315 
316 	    got_good=1;
317 	}
318 
319 	if (!got_good)
320 	{
321 	    if (up->linect > 0)
322 	    	up->linect--;
323 	    else
324 	    	refclock_report(peer, CEVNT_BADREPLY);
325 	    return;
326 	}
327 
328 	/*
329 	 * Process the new sample in the median filter and determine the
330 	 * timecode timestamp.
331 	 */
332 	if (!refclock_process(pp)) {
333 		refclock_report(peer, CEVNT_BADTIME);
334 		return;
335 	}
336 	pp->lastref = pp->lastrec;
337 	refclock_receive(peer);
338 	record_clock_stats(&peer->srcadr, pp->a_lastcode);
339 	up->lasthour = (u_char)pp->hour;
340 }
341 
342 #if 0
343 /*
344  * dumbclock_poll - called by the transmit procedure
345  */
346 static void
347 dumbclock_poll(
348 	int unit,
349 	struct peer *peer
350 	)
351 {
352 	register struct dumbclock_unit *up;
353 	struct refclockproc *pp;
354 	char pollchar;
355 
356 	/*
357 	 * Time to poll the clock. The Chrono-log clock is supposed to
358 	 * respond to a 'T' by returning a timecode in the format(s)
359 	 * specified above.  Ours does (can?) not, but this seems to be
360 	 * an installation-specific problem.  This code is dyked out,
361 	 * but may be re-enabled if anyone ever finds a Chrono-log that
362 	 * actually listens to this command.
363 	 */
364 #if 0
365 	pp = peer->procptr;
366 	up = pp->unitptr;
367 	if (peer->reach == 0)
368 		refclock_report(peer, CEVNT_TIMEOUT);
369 	if (up->linect > 0)
370 		pollchar = 'R';
371 	else
372 		pollchar = 'T';
373 	if (write(pp->io.fd, &pollchar, 1) != 1)
374 		refclock_report(peer, CEVNT_FAULT);
375 	else
376 		pp->polls++;
377 #endif
378 }
379 #endif
380 
381 #else
382 int refclock_dumbclock_bs;
383 #endif	/* defined(REFCLOCK) && defined(CLOCK_DUMBCLOCK) */
384