xref: /dragonfly/usr.sbin/newsyslog/ptimes.c (revision 279dd846)
1 /*-
2  * ------+---------+---------+---------+---------+---------+---------+---------*
3  * Initial version of parse8601 was originally added to newsyslog.c in
4  *     FreeBSD on Jan 22, 1999 by Garrett Wollman <wollman@FreeBSD.org>.
5  * Initial version of parseDWM was originally added to newsyslog.c in
6  *     FreeBSD on Apr  4, 2000 by Hellmuth Michaelis <hm@FreeBSD.org>.
7  *
8  * Copyright (c) 2003  - Garance Alistair Drosehn <gad@FreeBSD.org>.
9  * All rights reserved.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  *   1. Redistributions of source code must retain the above copyright
15  *      notice, this list of conditions and the following disclaimer.
16  *   2. Redistributions in binary form must reproduce the above copyright
17  *      notice, this list of conditions and the following disclaimer in the
18  *      documentation and/or other materials provided with the distribution.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  *
32  * The views and conclusions contained in the software and documentation
33  * are those of the authors and should not be interpreted as representing
34  * official policies, either expressed or implied, of the FreeBSD Project.
35  *
36  * ------+---------+---------+---------+---------+---------+---------+---------*
37  * This is intended to be a set of general-purpose routines to process times.
38  * Right now it probably still has a number of assumptions in it, such that
39  * it works fine for newsyslog but might not work for other uses.
40  * ------+---------+---------+---------+---------+---------+---------+---------*
41  *
42  * $FreeBSD: src/usr.sbin/newsyslog/ptimes.c,v 1.5 2004/06/07 21:53:27 gad Exp $
43  * $DragonFly: src/usr.sbin/newsyslog/ptimes.c,v 1.1 2007/05/12 08:52:00 swildner Exp $
44  */
45 
46 #include <ctype.h>
47 #include <limits.h>
48 #include <stdio.h>
49 #include <stdlib.h>
50 #include <string.h>
51 #include <time.h>
52 
53 #include "extern.h"
54 
55 #define	SECS_PER_HOUR	3600
56 
57 /*
58  * Bit-values which indicate which components of time were specified
59  * by the string given to parse8601 or parseDWM.  These are needed to
60  * calculate what time-in-the-future will match that string.
61  */
62 #define	TSPEC_YEAR		0x0001
63 #define	TSPEC_MONTHOFYEAR	0x0002
64 #define	TSPEC_LDAYOFMONTH	0x0004
65 #define	TSPEC_DAYOFMONTH	0x0008
66 #define	TSPEC_DAYOFWEEK		0x0010
67 #define	TSPEC_HOUROFDAY		0x0020
68 
69 #define	TNYET_ADJ4DST		-10	/* DST has "not yet" been adjusted */
70 
71 struct ptime_data {
72 	time_t		 basesecs;	/* Base point for relative times */
73 	time_t		 tsecs;		/* Time in seconds */
74 	struct tm	 basetm;	/* Base Time expanded into fields */
75 	struct tm	 tm;		/* Time expanded into fields */
76 	int		 did_adj4dst;	/* Track calls to ptime_adjust4dst */
77 	int		 parseopts;	/* Options given for parsing */
78 	int		 tmspec;	/* Indicates which time fields had
79 					 * been specified by the user */
80 };
81 
82 static int	 days_pmonth(int month, int year);
83 static int	 parse8601(struct ptime_data *ptime, const char *str);
84 static int	 parseDWM(struct ptime_data *ptime, const char *str);
85 
86 /*
87  * Simple routine to calculate the number of days in a given month.
88  */
89 static int
90 days_pmonth(int month, int year)
91 {
92 	static const int mtab[] = {31, 28, 31, 30, 31, 30, 31, 31,
93 	    30, 31, 30, 31};
94 	int ndays;
95 
96 	ndays = mtab[month];
97 
98 	if (month == 1) {
99 		/*
100 		 * We are usually called with a 'tm-year' value
101 		 * (ie, the value = the number of years past 1900).
102 		 */
103 		if (year < 1900)
104 			year += 1900;
105 		if (year % 4 == 0) {
106 			/*
107 			 * This is a leap year, as long as it is not a
108 			 * multiple of 100, or if it is a multiple of
109 			 * both 100 and 400.
110 			 */
111 			if (year % 100 != 0)
112 				ndays++;	/* not multiple of 100 */
113 			else if (year % 400 == 0)
114 				ndays++;	/* is multiple of 100 and 400 */
115 		}
116 	}
117 	return (ndays);
118 }
119 
120 /*-
121  * Parse a limited subset of ISO 8601. The specific format is as follows:
122  *
123  * [CC[YY[MM[DD]]]][THH[MM[SS]]]	(where `T' is the literal letter)
124  *
125  * We don't accept a timezone specification; missing fields (including timezone)
126  * are defaulted to the current date but time zero.
127  */
128 static int
129 parse8601(struct ptime_data *ptime, const char *s)
130 {
131 	char *t;
132 	long l;
133 	struct tm tm;
134 
135 	l = strtol(s, &t, 10);
136 	if (l < 0 || l >= INT_MAX || (*t != '\0' && *t != 'T'))
137 		return (-1);
138 
139 	/*
140 	 * Now t points either to the end of the string (if no time was
141 	 * provided) or to the letter `T' which separates date and time in
142 	 * ISO 8601.  The pointer arithmetic is the same for either case.
143 	 */
144 	tm = ptime->tm;
145 	ptime->tmspec = TSPEC_HOUROFDAY;
146 	switch (t - s) {
147 	case 8:
148 		tm.tm_year = ((l / 1000000) - 19) * 100;
149 		l = l % 1000000;
150 	case 6:
151 		ptime->tmspec |= TSPEC_YEAR;
152 		tm.tm_year -= tm.tm_year % 100;
153 		tm.tm_year += l / 10000;
154 		l = l % 10000;
155 	case 4:
156 		ptime->tmspec |= TSPEC_MONTHOFYEAR;
157 		tm.tm_mon = (l / 100) - 1;
158 		l = l % 100;
159 	case 2:
160 		ptime->tmspec |= TSPEC_DAYOFMONTH;
161 		tm.tm_mday = l;
162 	case 0:
163 		break;
164 	default:
165 		return (-1);
166 	}
167 
168 	/* sanity check */
169 	if (tm.tm_year < 70 || tm.tm_mon < 0 || tm.tm_mon > 12
170 	    || tm.tm_mday < 1 || tm.tm_mday > 31)
171 		return (-1);
172 
173 	if (*t != '\0') {
174 		s = ++t;
175 		l = strtol(s, &t, 10);
176 		if (l < 0 || l >= INT_MAX || (*t != '\0' && !isspace(*t)))
177 			return (-1);
178 
179 		switch (t - s) {
180 		case 6:
181 			tm.tm_sec = l % 100;
182 			l /= 100;
183 		case 4:
184 			tm.tm_min = l % 100;
185 			l /= 100;
186 		case 2:
187 			ptime->tmspec |= TSPEC_HOUROFDAY;
188 			tm.tm_hour = l;
189 		case 0:
190 			break;
191 		default:
192 			return (-1);
193 		}
194 
195 		/* sanity check */
196 		if (tm.tm_sec < 0 || tm.tm_sec > 60 || tm.tm_min < 0
197 		    || tm.tm_min > 59 || tm.tm_hour < 0 || tm.tm_hour > 23)
198 			return (-1);
199 	}
200 
201 	ptime->tm = tm;
202 	return (0);
203 }
204 
205 /*-
206  * Parse a cyclic time specification, the format is as follows:
207  *
208  *	[Dhh] or [Wd[Dhh]] or [Mdd[Dhh]]
209  *
210  * to rotate a logfile cyclic at
211  *
212  *	- every day (D) within a specific hour (hh)	(hh = 0...23)
213  *	- once a week (W) at a specific day (d)     OR	(d = 0..6, 0 = Sunday)
214  *	- once a month (M) at a specific day (d)	(d = 1..31,l|L)
215  *
216  * We don't accept a timezone specification; missing fields
217  * are defaulted to the current date but time zero.
218  */
219 static int
220 parseDWM(struct ptime_data *ptime, const char *s)
221 {
222 	int daysmon, Dseen, WMseen;
223 	const char *endval;
224 	char *tmp;
225 	long l;
226 	struct tm tm;
227 
228 	/* Save away the number of days in this month */
229 	tm = ptime->tm;
230 	daysmon = days_pmonth(tm.tm_mon, tm.tm_year);
231 
232 	WMseen = Dseen = 0;
233 	ptime->tmspec = TSPEC_HOUROFDAY;
234 	for (;;) {
235 		endval = NULL;
236 		switch (*s) {
237 		case 'D':
238 			if (Dseen)
239 				return (-1);
240 			Dseen++;
241 			ptime->tmspec |= TSPEC_HOUROFDAY;
242 			s++;
243 			l = strtol(s, &tmp, 10);
244 			if (l < 0 || l > 23)
245 				return (-1);
246 			endval = tmp;
247 			tm.tm_hour = l;
248 			break;
249 
250 		case 'W':
251 			if (WMseen)
252 				return (-1);
253 			WMseen++;
254 			ptime->tmspec |= TSPEC_DAYOFWEEK;
255 			s++;
256 			l = strtol(s, &tmp, 10);
257 			if (l < 0 || l > 6)
258 				return (-1);
259 			endval = tmp;
260 			if (l != tm.tm_wday) {
261 				int save;
262 
263 				if (l < tm.tm_wday) {
264 					save = 6 - tm.tm_wday;
265 					save += (l + 1);
266 				} else {
267 					save = l - tm.tm_wday;
268 				}
269 
270 				tm.tm_mday += save;
271 
272 				if (tm.tm_mday > daysmon) {
273 					tm.tm_mon++;
274 					tm.tm_mday = tm.tm_mday - daysmon;
275 				}
276 			}
277 			break;
278 
279 		case 'M':
280 			if (WMseen)
281 				return (-1);
282 			WMseen++;
283 			ptime->tmspec |= TSPEC_DAYOFMONTH;
284 			s++;
285 			if (tolower(*s) == 'l') {
286 				/* User wants the last day of the month. */
287 				ptime->tmspec |= TSPEC_LDAYOFMONTH;
288 				tm.tm_mday = daysmon;
289 				endval = s + 1;
290 			} else {
291 				l = strtol(s, &tmp, 10);
292 				if (l < 1 || l > 31)
293 					return (-1);
294 
295 				if (l > daysmon)
296 					return (-1);
297 				endval = tmp;
298 				tm.tm_mday = l;
299 			}
300 			break;
301 
302 		default:
303 			return (-1);
304 			break;
305 		}
306 
307 		if (endval == NULL)
308 			return (-1);
309 		else if (*endval == '\0' || isspace(*endval))
310 			break;
311 		else
312 			s = endval;
313 	}
314 
315 	ptime->tm = tm;
316 	return (0);
317 }
318 
319 /*
320  * Initialize a new ptime-related data area.
321  */
322 struct ptime_data *
323 ptime_init(const struct ptime_data *optsrc)
324 {
325 	struct ptime_data *newdata;
326 
327 	newdata = malloc(sizeof(struct ptime_data));
328 	if (optsrc != NULL) {
329 		memcpy(newdata, optsrc, sizeof(struct ptime_data));
330 	} else {
331 		memset(newdata, '\0', sizeof(struct ptime_data));
332 		newdata->did_adj4dst = TNYET_ADJ4DST;
333 	}
334 
335 	return (newdata);
336 }
337 
338 /*
339  * Adjust a given time if that time is in a different timezone than
340  * some other time.
341  */
342 int
343 ptime_adjust4dst(struct ptime_data *ptime, const struct ptime_data *dstsrc)
344 {
345 	struct ptime_data adjtim;
346 
347 	if (ptime == NULL)
348 		return (-1);
349 
350 	/*
351 	 * Changes are not made to the given time until after all
352 	 * of the calculations have been successful.
353 	 */
354 	adjtim = *ptime;
355 
356 	/* Check to see if this adjustment was already made */
357 	if ((adjtim.did_adj4dst != TNYET_ADJ4DST) &&
358 	    (adjtim.did_adj4dst == dstsrc->tm.tm_isdst))
359 		return (0);		/* yes, so don't make it twice */
360 
361 	/* See if daylight-saving has changed between the two times. */
362 	if (dstsrc->tm.tm_isdst != adjtim.tm.tm_isdst) {
363 		if (adjtim.tm.tm_isdst == 1)
364 			adjtim.tsecs -= SECS_PER_HOUR;
365 		else if (adjtim.tm.tm_isdst == 0)
366 			adjtim.tsecs += SECS_PER_HOUR;
367 		adjtim.tm = *(localtime(&adjtim.tsecs));
368 		/* Remember that this adjustment has been made */
369 		adjtim.did_adj4dst = dstsrc->tm.tm_isdst;
370 		/*
371 		 * XXX - Should probably check to see if changing the
372 		 *	hour also changed the value of is_dst.  What
373 		 *	should we do in that case?
374 		 */
375 	}
376 
377 	*ptime = adjtim;
378 	return (0);
379 }
380 
381 int
382 ptime_relparse(struct ptime_data *ptime, int parseopts, time_t basetime,
383     const char *str)
384 {
385 	int dpm, pres;
386 	struct tm temp_tm;
387 
388 	ptime->parseopts = parseopts;
389 	ptime->basesecs = basetime;
390 	ptime->basetm = *(localtime(&ptime->basesecs));
391 	ptime->tm = ptime->basetm;
392 	ptime->tm.tm_hour = ptime->tm.tm_min = ptime->tm.tm_sec = 0;
393 
394 	/*
395 	 * Call a routine which sets ptime.tm and ptime.tspecs based
396 	 * on the given string and parsing-options.  Note that the
397 	 * routine should not call mktime to set ptime.tsecs.
398 	 */
399 	if (parseopts & PTM_PARSE_DWM)
400 		pres = parseDWM(ptime, str);
401 	else
402 		pres = parse8601(ptime, str);
403 	if (pres < 0) {
404 		ptime->tsecs = (time_t)pres;
405 		return (pres);
406 	}
407 
408 	/*
409 	 * Before calling mktime, check to see if we ended up with a
410 	 * "day-of-month" that does not exist in the selected month.
411 	 * If we did call mktime with that info, then mktime will
412 	 * make it look like the user specifically requested a day
413 	 * in the following month (eg: Feb 31 turns into Mar 3rd).
414 	 */
415 	dpm = days_pmonth(ptime->tm.tm_mon, ptime->tm.tm_year);
416 	if ((parseopts & PTM_PARSE_MATCHDOM) &&
417 	    (ptime->tmspec & TSPEC_DAYOFMONTH) &&
418 	    (ptime->tm.tm_mday> dpm)) {
419 		/*
420 		 * ptime_nxtime() will want a ptime->tsecs value,
421 		 * but we need to avoid mktime resetting all the
422 		 * ptime->tm values.
423 		 */
424 		if (verbose && dbg_at_times > 1)
425 			fprintf(stderr,
426 			    "\t-- dom fixed: %4d/%02d/%02d %02d:%02d (%02d)",
427 			    ptime->tm.tm_year, ptime->tm.tm_mon,
428 			    ptime->tm.tm_mday, ptime->tm.tm_hour,
429 			    ptime->tm.tm_min, dpm);
430 		temp_tm = ptime->tm;
431 		ptime->tsecs = mktime(&temp_tm);
432 		if (ptime->tsecs > (time_t)-1)
433 			ptimeset_nxtime(ptime);
434 		if (verbose && dbg_at_times > 1)
435 			fprintf(stderr,
436 			    " to: %4d/%02d/%02d %02d:%02d\n",
437 			    ptime->tm.tm_year, ptime->tm.tm_mon,
438 			    ptime->tm.tm_mday, ptime->tm.tm_hour,
439 			    ptime->tm.tm_min);
440 	}
441 
442 	/*
443 	 * Convert the ptime.tm into standard time_t seconds.  Check
444 	 * for invalid times, which includes things like the hour lost
445 	 * when switching from "standard time" to "daylight saving".
446 	 */
447 	ptime->tsecs = mktime(&ptime->tm);
448 	if (ptime->tsecs == (time_t)-1) {
449 		ptime->tsecs = (time_t)-2;
450 		return (-2);
451 	}
452 
453 	return (0);
454 }
455 
456 int
457 ptime_free(struct ptime_data *ptime)
458 {
459 
460 	if (ptime == NULL)
461 		return (-1);
462 
463 	free(ptime);
464 	return (0);
465 }
466 
467 /*
468  * Some trivial routines so ptime_data can remain a completely
469  * opaque type.
470  */
471 const char *
472 ptimeget_ctime(const struct ptime_data *ptime)
473 {
474 
475 	if (ptime == NULL)
476 		return ("Null time in ptimeget_ctime()\n");
477 
478 	return (ctime(&ptime->tsecs));
479 }
480 
481 double
482 ptimeget_diff(const struct ptime_data *minuend, const struct
483     ptime_data *subtrahend)
484 {
485 
486 	/* Just like difftime(), we have no good error-return */
487 	if (minuend == NULL || subtrahend == NULL)
488 		return (0.0);
489 
490 	return (difftime(minuend->tsecs, subtrahend->tsecs));
491 }
492 
493 time_t
494 ptimeget_secs(const struct ptime_data *ptime)
495 {
496 
497 	if (ptime == NULL)
498 		return (-1);
499 
500 	return (ptime->tsecs);
501 }
502 
503 /*
504  * Generate an approximate timestamp for the next event, based on
505  * what parts of time were specified by the original parameter to
506  * ptime_relparse(). The result may be -1 if there is no obvious
507  * "next time" which will work.
508  */
509 int
510 ptimeset_nxtime(struct ptime_data *ptime)
511 {
512 	int moredays, tdpm, tmon, tyear;
513 	struct ptime_data nextmatch;
514 
515 	if (ptime == NULL)
516 		return (-1);
517 
518 	/*
519 	 * Changes are not made to the given time until after all
520 	 * of the calculations have been successful.
521 	 */
522 	nextmatch = *ptime;
523 	/*
524 	 * If the user specified a year and we're already past that
525 	 * time, then there will never be another one!
526 	 */
527 	if (ptime->tmspec & TSPEC_YEAR)
528 		return (-1);
529 
530 	/*
531 	 * The caller gave us a time in the past.  Calculate how much
532 	 * time is needed to go from that valid rotate time to the
533 	 * next valid rotate time.  We only need to get to the nearest
534 	 * hour, because newsyslog is only run once per hour.
535 	 */
536 	moredays = 0;
537 	if (ptime->tmspec & TSPEC_MONTHOFYEAR) {
538 		/* Special case: Feb 29th does not happen every year. */
539 		if (ptime->tm.tm_mon == 1 && ptime->tm.tm_mday == 29) {
540 			nextmatch.tm.tm_year += 4;
541 			if (days_pmonth(1, nextmatch.tm.tm_year) < 29)
542 				nextmatch.tm.tm_year += 4;
543 		} else {
544 			nextmatch.tm.tm_year += 1;
545 		}
546 		nextmatch.tm.tm_isdst = -1;
547 		nextmatch.tsecs = mktime(&nextmatch.tm);
548 
549 	} else if (ptime->tmspec & TSPEC_LDAYOFMONTH) {
550 		/*
551 		 * Need to get to the last day of next month.  Origtm is
552 		 * already at the last day of this month, so just add to
553 		 * it number of days in the next month.
554 		 */
555 		if (ptime->tm.tm_mon < 11)
556 			moredays = days_pmonth(ptime->tm.tm_mon + 1,
557 			    ptime->tm.tm_year);
558 		else
559 			moredays = days_pmonth(0, ptime->tm.tm_year + 1);
560 
561 	} else if (ptime->tmspec & TSPEC_DAYOFMONTH) {
562 		/* Jump to the same day in the next month */
563 		moredays = days_pmonth(ptime->tm.tm_mon, ptime->tm.tm_year);
564 		/*
565 		 * In some cases, the next month may not *have* the
566 		 * desired day-of-the-month.  If that happens, then
567 		 * move to the next month that does have enough days.
568 		 */
569 		tmon = ptime->tm.tm_mon;
570 		tyear = ptime->tm.tm_year;
571 		for (;;) {
572 			if (tmon < 11)
573 				tmon += 1;
574 			else {
575 				tmon = 0;
576 				tyear += 1;
577 			}
578 			tdpm = days_pmonth(tmon, tyear);
579 			if (tdpm >= ptime->tm.tm_mday)
580 				break;
581 			moredays += tdpm;
582 		}
583 
584 	} else if (ptime->tmspec & TSPEC_DAYOFWEEK) {
585 		moredays = 7;
586 	} else if (ptime->tmspec & TSPEC_HOUROFDAY) {
587 		moredays = 1;
588 	}
589 
590 	if (moredays != 0) {
591 		nextmatch.tsecs += SECS_PER_HOUR * 24 * moredays;
592 		nextmatch.tm = *(localtime(&nextmatch.tsecs));
593 	}
594 
595 	/*
596 	 * The new time will need to be adjusted if the setting of
597 	 * daylight-saving has changed between the two times.
598 	 */
599 	ptime_adjust4dst(&nextmatch, ptime);
600 
601 	/* Everything worked.  Update the given time and return. */
602 	*ptime = nextmatch;
603 	return (0);
604 }
605 
606 int
607 ptimeset_time(struct ptime_data *ptime, time_t secs)
608 {
609 
610 	if (ptime == NULL)
611 		return (-1);
612 
613 	ptime->tsecs = secs;
614 	ptime->tm = *(localtime(&ptime->tsecs));
615 	ptime->parseopts = 0;
616 	/* ptime->tmspec = ? */
617 	return (0);
618 }
619