xref: /netbsd-src/lib/libc/time/localtime.c (revision dc306354b0b29af51801a7632f1e95265a68cd81)
1 /*	$NetBSD: localtime.c,v 1.21 1998/11/15 17:11:06 christos Exp $	*/
2 
3 /*
4 ** This file is in the public domain, so clarified as of
5 ** 1996-06-05 by Arthur David Olson (arthur_david_olson@nih.gov).
6 */
7 
8 #include <sys/cdefs.h>
9 #ifndef lint
10 #ifndef NOID
11 #if 0
12 static char	elsieid[] = "@(#)localtime.c	7.66";
13 #else
14 __RCSID("$NetBSD: localtime.c,v 1.21 1998/11/15 17:11:06 christos Exp $");
15 #endif
16 #endif /* !defined NOID */
17 #endif /* !defined lint */
18 
19 /*
20 ** Leap second handling from Bradley White (bww@k.gp.cs.cmu.edu).
21 ** POSIX-style TZ environment variable handling from Guy Harris
22 ** (guy@auspex.com).
23 */
24 
25 /*LINTLIBRARY*/
26 
27 #include "namespace.h"
28 #include "private.h"
29 #include "tzfile.h"
30 #include "fcntl.h"
31 #include "reentrant.h"
32 
33 #ifdef __weak_alias
34 __weak_alias(ctime_r,_ctime_r);
35 __weak_alias(gmtime_r,_gmtime_r);
36 __weak_alias(localtime_r,_localtime_r);
37 __weak_alias(offtime,_offtime);
38 __weak_alias(posix2time,_posix2time);
39 __weak_alias(time2posix,_time2posix);
40 __weak_alias(timegm,_timegm);
41 __weak_alias(timelocal,_timelocal);
42 __weak_alias(timeoff,_timeoff);
43 __weak_alias(tzname,_tzname);
44 __weak_alias(tzset,_tzset);
45 __weak_alias(tzsetwall,_tzsetwall);
46 #endif
47 
48 /*
49 ** SunOS 4.1.1 headers lack O_BINARY.
50 */
51 
52 #ifdef O_BINARY
53 #define OPEN_MODE	(O_RDONLY | O_BINARY)
54 #endif /* defined O_BINARY */
55 #ifndef O_BINARY
56 #define OPEN_MODE	O_RDONLY
57 #endif /* !defined O_BINARY */
58 
59 #ifndef WILDABBR
60 /*
61 ** Someone might make incorrect use of a time zone abbreviation:
62 **	1.	They might reference tzname[0] before calling tzset (explicitly
63 **		or implicitly).
64 **	2.	They might reference tzname[1] before calling tzset (explicitly
65 **		or implicitly).
66 **	3.	They might reference tzname[1] after setting to a time zone
67 **		in which Daylight Saving Time is never observed.
68 **	4.	They might reference tzname[0] after setting to a time zone
69 **		in which Standard Time is never observed.
70 **	5.	They might reference tm.TM_ZONE after calling offtime.
71 ** What's best to do in the above cases is open to debate;
72 ** for now, we just set things up so that in any of the five cases
73 ** WILDABBR is used.  Another possibility:  initialize tzname[0] to the
74 ** string "tzname[0] used before set", and similarly for the other cases.
75 ** And another:  initialize tzname[0] to "ERA", with an explanation in the
76 ** manual page of what this "time zone abbreviation" means (doing this so
77 ** that tzname[0] has the "normal" length of three characters).
78 */
79 #define WILDABBR	"   "
80 #endif /* !defined WILDABBR */
81 
82 static const char	wildabbr[] = "WILDABBR";
83 
84 static const char	gmt[] = "GMT";
85 
86 struct ttinfo {				/* time type information */
87 	long		tt_gmtoff;	/* UTC offset in seconds */
88 	int		tt_isdst;	/* used to set tm_isdst */
89 	int		tt_abbrind;	/* abbreviation list index */
90 	int		tt_ttisstd;	/* TRUE if transition is std time */
91 	int		tt_ttisgmt;	/* TRUE if transition is UTC */
92 };
93 
94 struct lsinfo {				/* leap second information */
95 	time_t		ls_trans;	/* transition time */
96 	long		ls_corr;	/* correction to apply */
97 };
98 
99 #define BIGGEST(a, b)	(((a) > (b)) ? (a) : (b))
100 
101 #ifdef TZNAME_MAX
102 #define MY_TZNAME_MAX	TZNAME_MAX
103 #endif /* defined TZNAME_MAX */
104 #ifndef TZNAME_MAX
105 #define MY_TZNAME_MAX	255
106 #endif /* !defined TZNAME_MAX */
107 
108 struct state {
109 	int		leapcnt;
110 	int		timecnt;
111 	int		typecnt;
112 	int		charcnt;
113 	time_t		ats[TZ_MAX_TIMES];
114 	unsigned char	types[TZ_MAX_TIMES];
115 	struct ttinfo	ttis[TZ_MAX_TYPES];
116 	char		chars[/* LINTED constant */BIGGEST(BIGGEST(TZ_MAX_CHARS + 1, sizeof gmt),
117 				(2 * (MY_TZNAME_MAX + 1)))];
118 	struct lsinfo	lsis[TZ_MAX_LEAPS];
119 };
120 
121 struct rule {
122 	int		r_type;		/* type of rule--see below */
123 	int		r_day;		/* day number of rule */
124 	int		r_week;		/* week number of rule */
125 	int		r_mon;		/* month number of rule */
126 	long		r_time;		/* transition time of rule */
127 };
128 
129 #define JULIAN_DAY		0	/* Jn - Julian day */
130 #define DAY_OF_YEAR		1	/* n - day of year */
131 #define MONTH_NTH_DAY_OF_WEEK	2	/* Mm.n.d - month, week, day of week */
132 
133 /*
134 ** Prototypes for static functions.
135 */
136 
137 static long		detzcode P((const char * codep));
138 static const char *	getzname P((const char * strp));
139 static const char *	getnum P((const char * strp, int * nump, int min,
140 				int max));
141 static const char *	getsecs P((const char * strp, long * secsp));
142 static const char *	getoffset P((const char * strp, long * offsetp));
143 static const char *	getrule P((const char * strp, struct rule * rulep));
144 static void		gmtload P((struct state * sp));
145 static void		gmtsub P((const time_t * timep, long offset,
146 				struct tm * tmp));
147 static void		localsub P((const time_t * timep, long offset,
148 				struct tm * tmp));
149 static int		increment_overflow P((int * number, int delta));
150 static int		normalize_overflow P((int * tensptr, int * unitsptr,
151 				int base));
152 static void		settzname P((void));
153 static time_t		time1 P((struct tm * tmp,
154 				void(*funcp) P((const time_t *,
155 				long, struct tm *)),
156 				long offset));
157 static time_t		time2 P((struct tm *tmp,
158 				void(*funcp) P((const time_t *,
159 				long, struct tm*)),
160 				long offset, int * okayp));
161 static time_t		time2sub P((struct tm *tmp,
162 				void(*funcp) P((const time_t *,
163 				long, struct tm*)),
164 				long offset, int * okayp, int do_norm_secs));
165 static void		timesub P((const time_t * timep, long offset,
166 				const struct state * sp, struct tm * tmp));
167 static int		tmcomp P((const struct tm * atmp,
168 				const struct tm * btmp));
169 static time_t		transtime P((time_t janfirst, int year,
170 				const struct rule * rulep, long offset));
171 static int		tzload P((const char * name, struct state * sp));
172 static int		tzparse P((const char * name, struct state * sp,
173 				int lastditch));
174 static void		tzset_unlocked P((void));
175 static void		tzsetwall_unlocked P((void));
176 #ifdef STD_INSPIRED
177 static long		leapcorr P((time_t * timep));
178 #endif
179 
180 #ifdef ALL_STATE
181 static struct state *	lclptr;
182 static struct state *	gmtptr;
183 #endif /* defined ALL_STATE */
184 
185 #ifndef ALL_STATE
186 static struct state	lclmem;
187 static struct state	gmtmem;
188 #define lclptr		(&lclmem)
189 #define gmtptr		(&gmtmem)
190 #endif /* State Farm */
191 
192 #ifndef TZ_STRLEN_MAX
193 #define TZ_STRLEN_MAX 255
194 #endif /* !defined TZ_STRLEN_MAX */
195 
196 static char		lcl_TZname[TZ_STRLEN_MAX + 1];
197 static int		lcl_is_set;
198 static int		gmt_is_set;
199 
200 __aconst char *		tzname[2] = {
201 	/* LINTED const castaway */
202 	(__aconst char *)wildabbr,
203 	/* LINTED const castaway */
204 	(__aconst char *)wildabbr
205 };
206 
207 #ifdef _REENT
208 static rwlock_t lcl_lock = RWLOCK_INITIALIZER;
209 #endif
210 
211 /*
212 ** Section 4.12.3 of X3.159-1989 requires that
213 **	Except for the strftime function, these functions [asctime,
214 **	ctime, gmtime, localtime] return values in one of two static
215 **	objects: a broken-down time structure and an array of char.
216 ** Thanks to Paul Eggert (eggert@twinsun.com) for noting this.
217 */
218 
219 static struct tm	tm;
220 
221 #ifdef USG_COMPAT
222 time_t			timezone = 0;
223 int			daylight = 0;
224 #endif /* defined USG_COMPAT */
225 
226 #ifdef ALTZONE
227 time_t			altzone = 0;
228 #endif /* defined ALTZONE */
229 
230 static long
231 detzcode(codep)
232 const char * const	codep;
233 {
234 	register long	result;
235 
236 	/*
237         ** The first character must be sign extended on systems with >32bit
238         ** longs.  This was solved differently in the master tzcode sources
239         ** (the fix first appeared in tzcode95c.tar.gz).  But I believe
240 	** that this implementation is superior.
241         */
242 
243 #ifdef __STDC__
244 #define SIGN_EXTEND_CHAR(x)	((signed char) x)
245 #else
246 #define SIGN_EXTEND_CHAR(x)	((x & 0x80) ? ((~0 << 8) | x) : x)
247 #endif
248 
249 	result = (SIGN_EXTEND_CHAR(codep[0]) << 24) \
250 	       | (codep[1] & 0xff) << 16 \
251 	       | (codep[2] & 0xff) << 8
252 	       | (codep[3] & 0xff);
253 	return result;
254 }
255 
256 static void
257 settzname P((void))
258 {
259 	register struct state * const	sp = lclptr;
260 	register int			i;
261 
262 	/* LINTED const castaway */
263 	tzname[0] = (__aconst char *)wildabbr;
264 	/* LINTED const castaway */
265 	tzname[1] = (__aconst char *)wildabbr;
266 #ifdef USG_COMPAT
267 	daylight = 0;
268 	timezone = 0;
269 #endif /* defined USG_COMPAT */
270 #ifdef ALTZONE
271 	altzone = 0;
272 #endif /* defined ALTZONE */
273 #ifdef ALL_STATE
274 	if (sp == NULL) {
275 		tzname[0] = tzname[1] = (__aconst char *)gmt;
276 		return;
277 	}
278 #endif /* defined ALL_STATE */
279 	for (i = 0; i < sp->typecnt; ++i) {
280 		register const struct ttinfo * const	ttisp = &sp->ttis[i];
281 
282 		tzname[ttisp->tt_isdst] =
283 			&sp->chars[ttisp->tt_abbrind];
284 #ifdef USG_COMPAT
285 		if (ttisp->tt_isdst)
286 			daylight = 1;
287 		if (i == 0 || !ttisp->tt_isdst)
288 			timezone = -(ttisp->tt_gmtoff);
289 #endif /* defined USG_COMPAT */
290 #ifdef ALTZONE
291 		if (i == 0 || ttisp->tt_isdst)
292 			altzone = -(ttisp->tt_gmtoff);
293 #endif /* defined ALTZONE */
294 	}
295 	/*
296 	** And to get the latest zone names into tzname. . .
297 	*/
298 	for (i = 0; i < sp->timecnt; ++i) {
299 		register const struct ttinfo * const	ttisp =
300 							&sp->ttis[
301 								sp->types[i]];
302 
303 		tzname[ttisp->tt_isdst] =
304 			&sp->chars[ttisp->tt_abbrind];
305 	}
306 }
307 
308 static int
309 tzload(name, sp)
310 register const char *		name;
311 register struct state * const	sp;
312 {
313 	register const char *	p;
314 	register int		i;
315 	register int		fid;
316 
317 	if (name == NULL && (name = TZDEFAULT) == NULL)
318 		return -1;
319 
320 	{
321 		register int	doaccess;
322 		/*
323 		** Section 4.9.1 of the C standard says that
324 		** "FILENAME_MAX expands to an integral constant expression
325 		** that is the size needed for an array of char large enough
326 		** to hold the longest file name string that the implementation
327 		** guarantees can be opened."
328 		*/
329 		char		fullname[FILENAME_MAX + 1];
330 
331 		if (name[0] == ':')
332 			++name;
333 		doaccess = name[0] == '/';
334 		if (!doaccess) {
335 			if ((p = TZDIR) == NULL)
336 				return -1;
337 			if ((strlen(p) + strlen(name) + 1) >= sizeof fullname)
338 				return -1;
339 			(void) strcpy(fullname, p);	/* XXX strcpy is safe */
340 			(void) strcat(fullname, "/");	/* XXX strcat is safe */
341 			(void) strcat(fullname, name);	/* XXX strcat is safe */
342 			/*
343 			** Set doaccess if '.' (as in "../") shows up in name.
344 			*/
345 			if (strchr(name, '.') != NULL)
346 				doaccess = TRUE;
347 			name = fullname;
348 		}
349 		if (doaccess && access(name, R_OK) != 0)
350 			return -1;
351 		/*
352 		 * XXX potential security problem here if user of a set-id
353 		 * program has set TZ (which is passed in as name) here,
354 		 * and uses a race condition trick to defeat the access(2)
355 		 * above.
356 		 */
357 		if ((fid = open(name, OPEN_MODE)) == -1)
358 			return -1;
359 	}
360 	{
361 		struct tzhead *	tzhp;
362 		union {
363 		  struct tzhead tzhead;
364 		  char		buf[sizeof *sp + sizeof *tzhp];
365 		} u;
366 		int		ttisstdcnt;
367 		int		ttisgmtcnt;
368 
369 		i = read(fid, u.buf, sizeof u.buf);
370 		if (close(fid) != 0)
371 			return -1;
372 		ttisstdcnt = (int) detzcode(u.tzhead.tzh_ttisgmtcnt);
373 		ttisgmtcnt = (int) detzcode(u.tzhead.tzh_ttisstdcnt);
374 		sp->leapcnt = (int) detzcode(u.tzhead.tzh_leapcnt);
375 		sp->timecnt = (int) detzcode(u.tzhead.tzh_timecnt);
376 		sp->typecnt = (int) detzcode(u.tzhead.tzh_typecnt);
377 		sp->charcnt = (int) detzcode(u.tzhead.tzh_charcnt);
378 		p = u.tzhead.tzh_charcnt + sizeof u.tzhead.tzh_charcnt;
379 		if (sp->leapcnt < 0 || sp->leapcnt > TZ_MAX_LEAPS ||
380 			sp->typecnt <= 0 || sp->typecnt > TZ_MAX_TYPES ||
381 			sp->timecnt < 0 || sp->timecnt > TZ_MAX_TIMES ||
382 			sp->charcnt < 0 || sp->charcnt > TZ_MAX_CHARS ||
383 			(ttisstdcnt != sp->typecnt && ttisstdcnt != 0) ||
384 			(ttisgmtcnt != sp->typecnt && ttisgmtcnt != 0))
385 				return -1;
386 		if (i - (p - u.buf) < sp->timecnt * 4 +	/* ats */
387 			sp->timecnt +			/* types */
388 			sp->typecnt * (4 + 2) +		/* ttinfos */
389 			sp->charcnt +			/* chars */
390 			sp->leapcnt * (4 + 4) +		/* lsinfos */
391 			ttisstdcnt +			/* ttisstds */
392 			ttisgmtcnt)			/* ttisgmts */
393 				return -1;
394 		for (i = 0; i < sp->timecnt; ++i) {
395 			sp->ats[i] = detzcode(p);
396 			p += 4;
397 		}
398 		for (i = 0; i < sp->timecnt; ++i) {
399 			sp->types[i] = (unsigned char) *p++;
400 			if (sp->types[i] >= sp->typecnt)
401 				return -1;
402 		}
403 		for (i = 0; i < sp->typecnt; ++i) {
404 			register struct ttinfo *	ttisp;
405 
406 			ttisp = &sp->ttis[i];
407 			ttisp->tt_gmtoff = detzcode(p);
408 			p += 4;
409 			ttisp->tt_isdst = (unsigned char) *p++;
410 			if (ttisp->tt_isdst != 0 && ttisp->tt_isdst != 1)
411 				return -1;
412 			ttisp->tt_abbrind = (unsigned char) *p++;
413 			if (ttisp->tt_abbrind < 0 ||
414 				ttisp->tt_abbrind > sp->charcnt)
415 					return -1;
416 		}
417 		for (i = 0; i < sp->charcnt; ++i)
418 			sp->chars[i] = *p++;
419 		sp->chars[i] = '\0';	/* ensure '\0' at end */
420 		for (i = 0; i < sp->leapcnt; ++i) {
421 			register struct lsinfo *	lsisp;
422 
423 			lsisp = &sp->lsis[i];
424 			lsisp->ls_trans = detzcode(p);
425 			p += 4;
426 			lsisp->ls_corr = detzcode(p);
427 			p += 4;
428 		}
429 		for (i = 0; i < sp->typecnt; ++i) {
430 			register struct ttinfo *	ttisp;
431 
432 			ttisp = &sp->ttis[i];
433 			if (ttisstdcnt == 0)
434 				ttisp->tt_ttisstd = FALSE;
435 			else {
436 				ttisp->tt_ttisstd = *p++;
437 				if (ttisp->tt_ttisstd != TRUE &&
438 					ttisp->tt_ttisstd != FALSE)
439 						return -1;
440 			}
441 		}
442 		for (i = 0; i < sp->typecnt; ++i) {
443 			register struct ttinfo *	ttisp;
444 
445 			ttisp = &sp->ttis[i];
446 			if (ttisgmtcnt == 0)
447 				ttisp->tt_ttisgmt = FALSE;
448 			else {
449 				ttisp->tt_ttisgmt = *p++;
450 				if (ttisp->tt_ttisgmt != TRUE &&
451 					ttisp->tt_ttisgmt != FALSE)
452 						return -1;
453 			}
454 		}
455 	}
456 	return 0;
457 }
458 
459 static const int	mon_lengths[2][MONSPERYEAR] = {
460 	{ 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 },
461 	{ 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }
462 };
463 
464 static const int	year_lengths[2] = {
465 	DAYSPERNYEAR, DAYSPERLYEAR
466 };
467 
468 /*
469 ** Given a pointer into a time zone string, scan until a character that is not
470 ** a valid character in a zone name is found.  Return a pointer to that
471 ** character.
472 */
473 
474 static const char *
475 getzname(strp)
476 register const char *	strp;
477 {
478 	register char	c;
479 
480 	while ((c = *strp) != '\0' && !is_digit(c) && c != ',' && c != '-' &&
481 		c != '+')
482 			++strp;
483 	return strp;
484 }
485 
486 /*
487 ** Given a pointer into a time zone string, extract a number from that string.
488 ** Check that the number is within a specified range; if it is not, return
489 ** NULL.
490 ** Otherwise, return a pointer to the first character not part of the number.
491 */
492 
493 static const char *
494 getnum(strp, nump, min, max)
495 register const char *	strp;
496 int * const		nump;
497 const int		min;
498 const int		max;
499 {
500 	register char	c;
501 	register int	num;
502 
503 	if (strp == NULL || !is_digit(c = *strp))
504 		return NULL;
505 	num = 0;
506 	do {
507 		num = num * 10 + (c - '0');
508 		if (num > max)
509 			return NULL;	/* illegal value */
510 		c = *++strp;
511 	} while (is_digit(c));
512 	if (num < min)
513 		return NULL;		/* illegal value */
514 	*nump = num;
515 	return strp;
516 }
517 
518 /*
519 ** Given a pointer into a time zone string, extract a number of seconds,
520 ** in hh[:mm[:ss]] form, from the string.
521 ** If any error occurs, return NULL.
522 ** Otherwise, return a pointer to the first character not part of the number
523 ** of seconds.
524 */
525 
526 static const char *
527 getsecs(strp, secsp)
528 register const char *	strp;
529 long * const		secsp;
530 {
531 	int	num;
532 
533 	/*
534 	** `HOURSPERDAY * DAYSPERWEEK - 1' allows quasi-Posix rules like
535 	** "M10.4.6/26", which does not conform to Posix,
536 	** but which specifies the equivalent of
537 	** ``02:00 on the first Sunday on or after 23 Oct''.
538 	*/
539 	strp = getnum(strp, &num, 0, HOURSPERDAY * DAYSPERWEEK - 1);
540 	if (strp == NULL)
541 		return NULL;
542 	*secsp = num * (long) SECSPERHOUR;
543 	if (*strp == ':') {
544 		++strp;
545 		strp = getnum(strp, &num, 0, MINSPERHOUR - 1);
546 		if (strp == NULL)
547 			return NULL;
548 		*secsp += num * SECSPERMIN;
549 		if (*strp == ':') {
550 			++strp;
551 			/* `SECSPERMIN' allows for leap seconds.  */
552 			strp = getnum(strp, &num, 0, SECSPERMIN);
553 			if (strp == NULL)
554 				return NULL;
555 			*secsp += num;
556 		}
557 	}
558 	return strp;
559 }
560 
561 /*
562 ** Given a pointer into a time zone string, extract an offset, in
563 ** [+-]hh[:mm[:ss]] form, from the string.
564 ** If any error occurs, return NULL.
565 ** Otherwise, return a pointer to the first character not part of the time.
566 */
567 
568 static const char *
569 getoffset(strp, offsetp)
570 register const char *	strp;
571 long * const		offsetp;
572 {
573 	register int	neg = 0;
574 
575 	if (*strp == '-') {
576 		neg = 1;
577 		++strp;
578 	} else if (*strp == '+')
579 		++strp;
580 	strp = getsecs(strp, offsetp);
581 	if (strp == NULL)
582 		return NULL;		/* illegal time */
583 	if (neg)
584 		*offsetp = -*offsetp;
585 	return strp;
586 }
587 
588 /*
589 ** Given a pointer into a time zone string, extract a rule in the form
590 ** date[/time].  See POSIX section 8 for the format of "date" and "time".
591 ** If a valid rule is not found, return NULL.
592 ** Otherwise, return a pointer to the first character not part of the rule.
593 */
594 
595 static const char *
596 getrule(strp, rulep)
597 const char *			strp;
598 register struct rule * const	rulep;
599 {
600 	if (*strp == 'J') {
601 		/*
602 		** Julian day.
603 		*/
604 		rulep->r_type = JULIAN_DAY;
605 		++strp;
606 		strp = getnum(strp, &rulep->r_day, 1, DAYSPERNYEAR);
607 	} else if (*strp == 'M') {
608 		/*
609 		** Month, week, day.
610 		*/
611 		rulep->r_type = MONTH_NTH_DAY_OF_WEEK;
612 		++strp;
613 		strp = getnum(strp, &rulep->r_mon, 1, MONSPERYEAR);
614 		if (strp == NULL)
615 			return NULL;
616 		if (*strp++ != '.')
617 			return NULL;
618 		strp = getnum(strp, &rulep->r_week, 1, 5);
619 		if (strp == NULL)
620 			return NULL;
621 		if (*strp++ != '.')
622 			return NULL;
623 		strp = getnum(strp, &rulep->r_day, 0, DAYSPERWEEK - 1);
624 	} else if (is_digit(*strp)) {
625 		/*
626 		** Day of year.
627 		*/
628 		rulep->r_type = DAY_OF_YEAR;
629 		strp = getnum(strp, &rulep->r_day, 0, DAYSPERLYEAR - 1);
630 	} else	return NULL;		/* invalid format */
631 	if (strp == NULL)
632 		return NULL;
633 	if (*strp == '/') {
634 		/*
635 		** Time specified.
636 		*/
637 		++strp;
638 		strp = getsecs(strp, &rulep->r_time);
639 	} else	rulep->r_time = 2 * SECSPERHOUR;	/* default = 2:00:00 */
640 	return strp;
641 }
642 
643 /*
644 ** Given the Epoch-relative time of January 1, 00:00:00 UTC, in a year, the
645 ** year, a rule, and the offset from UTC at the time that rule takes effect,
646 ** calculate the Epoch-relative time that rule takes effect.
647 */
648 
649 static time_t
650 transtime(janfirst, year, rulep, offset)
651 const time_t				janfirst;
652 const int				year;
653 register const struct rule * const	rulep;
654 const long				offset;
655 {
656 	register int	leapyear;
657 	register time_t	value;
658 	register int	i;
659 	int		d, m1, yy0, yy1, yy2, dow;
660 
661 	INITIALIZE(value);
662 	leapyear = isleap(year);
663 	switch (rulep->r_type) {
664 
665 	case JULIAN_DAY:
666 		/*
667 		** Jn - Julian day, 1 == January 1, 60 == March 1 even in leap
668 		** years.
669 		** In non-leap years, or if the day number is 59 or less, just
670 		** add SECSPERDAY times the day number-1 to the time of
671 		** January 1, midnight, to get the day.
672 		*/
673 		value = janfirst + (rulep->r_day - 1) * SECSPERDAY;
674 		if (leapyear && rulep->r_day >= 60)
675 			value += SECSPERDAY;
676 		break;
677 
678 	case DAY_OF_YEAR:
679 		/*
680 		** n - day of year.
681 		** Just add SECSPERDAY times the day number to the time of
682 		** January 1, midnight, to get the day.
683 		*/
684 		value = janfirst + rulep->r_day * SECSPERDAY;
685 		break;
686 
687 	case MONTH_NTH_DAY_OF_WEEK:
688 		/*
689 		** Mm.n.d - nth "dth day" of month m.
690 		*/
691 		value = janfirst;
692 		for (i = 0; i < rulep->r_mon - 1; ++i)
693 			value += mon_lengths[leapyear][i] * SECSPERDAY;
694 
695 		/*
696 		** Use Zeller's Congruence to get day-of-week of first day of
697 		** month.
698 		*/
699 		m1 = (rulep->r_mon + 9) % 12 + 1;
700 		yy0 = (rulep->r_mon <= 2) ? (year - 1) : year;
701 		yy1 = yy0 / 100;
702 		yy2 = yy0 % 100;
703 		dow = ((26 * m1 - 2) / 10 +
704 			1 + yy2 + yy2 / 4 + yy1 / 4 - 2 * yy1) % 7;
705 		if (dow < 0)
706 			dow += DAYSPERWEEK;
707 
708 		/*
709 		** "dow" is the day-of-week of the first day of the month.  Get
710 		** the day-of-month (zero-origin) of the first "dow" day of the
711 		** month.
712 		*/
713 		d = rulep->r_day - dow;
714 		if (d < 0)
715 			d += DAYSPERWEEK;
716 		for (i = 1; i < rulep->r_week; ++i) {
717 			if (d + DAYSPERWEEK >=
718 				mon_lengths[leapyear][rulep->r_mon - 1])
719 					break;
720 			d += DAYSPERWEEK;
721 		}
722 
723 		/*
724 		** "d" is the day-of-month (zero-origin) of the day we want.
725 		*/
726 		value += d * SECSPERDAY;
727 		break;
728 	}
729 
730 	/*
731 	** "value" is the Epoch-relative time of 00:00:00 UTC on the day in
732 	** question.  To get the Epoch-relative time of the specified local
733 	** time on that day, add the transition time and the current offset
734 	** from UTC.
735 	*/
736 	return value + rulep->r_time + offset;
737 }
738 
739 /*
740 ** Given a POSIX section 8-style TZ string, fill in the rule tables as
741 ** appropriate.
742 */
743 
744 static int
745 tzparse(name, sp, lastditch)
746 const char *			name;
747 register struct state * const	sp;
748 const int			lastditch;
749 {
750 	const char *			stdname;
751 	const char *			dstname;
752 	size_t				stdlen;
753 	size_t				dstlen;
754 	long				stdoffset;
755 	long				dstoffset;
756 	register time_t *		atp;
757 	register unsigned char *	typep;
758 	register char *			cp;
759 	register int			load_result;
760 
761 	INITIALIZE(dstname);
762 	stdname = name;
763 	if (lastditch) {
764 		stdlen = strlen(name);	/* length of standard zone name */
765 		name += stdlen;
766 		if (stdlen >= sizeof sp->chars)
767 			stdlen = (sizeof sp->chars) - 1;
768 		stdoffset = 0;
769 	} else {
770 		name = getzname(name);
771 		stdlen = name - stdname;
772 		if (stdlen < 3)
773 			return -1;
774 		if (*name == '\0')
775 			return -1;
776 		name = getoffset(name, &stdoffset);
777 		if (name == NULL)
778 			return -1;
779 	}
780 	load_result = tzload(TZDEFRULES, sp);
781 	if (load_result != 0)
782 		sp->leapcnt = 0;		/* so, we're off a little */
783 	if (*name != '\0') {
784 		dstname = name;
785 		name = getzname(name);
786 		dstlen = name - dstname;	/* length of DST zone name */
787 		if (dstlen < 3)
788 			return -1;
789 		if (*name != '\0' && *name != ',' && *name != ';') {
790 			name = getoffset(name, &dstoffset);
791 			if (name == NULL)
792 				return -1;
793 		} else	dstoffset = stdoffset - SECSPERHOUR;
794 		if (*name == ',' || *name == ';') {
795 			struct rule	start;
796 			struct rule	end;
797 			register int	year;
798 			register time_t	janfirst;
799 			time_t		starttime;
800 			time_t		endtime;
801 
802 			++name;
803 			if ((name = getrule(name, &start)) == NULL)
804 				return -1;
805 			if (*name++ != ',')
806 				return -1;
807 			if ((name = getrule(name, &end)) == NULL)
808 				return -1;
809 			if (*name != '\0')
810 				return -1;
811 			sp->typecnt = 2;	/* standard time and DST */
812 			/*
813 			** Two transitions per year, from EPOCH_YEAR to 2037.
814 			*/
815 			sp->timecnt = 2 * (2037 - EPOCH_YEAR + 1);
816 			if (sp->timecnt > TZ_MAX_TIMES)
817 				return -1;
818 			sp->ttis[0].tt_gmtoff = -dstoffset;
819 			sp->ttis[0].tt_isdst = 1;
820 			sp->ttis[0].tt_abbrind = stdlen + 1;
821 			sp->ttis[1].tt_gmtoff = -stdoffset;
822 			sp->ttis[1].tt_isdst = 0;
823 			sp->ttis[1].tt_abbrind = 0;
824 			atp = sp->ats;
825 			typep = sp->types;
826 			janfirst = 0;
827 			for (year = EPOCH_YEAR; year <= 2037; ++year) {
828 				starttime = transtime(janfirst, year, &start,
829 					stdoffset);
830 				endtime = transtime(janfirst, year, &end,
831 					dstoffset);
832 				if (starttime > endtime) {
833 					*atp++ = endtime;
834 					*typep++ = 1;	/* DST ends */
835 					*atp++ = starttime;
836 					*typep++ = 0;	/* DST begins */
837 				} else {
838 					*atp++ = starttime;
839 					*typep++ = 0;	/* DST begins */
840 					*atp++ = endtime;
841 					*typep++ = 1;	/* DST ends */
842 				}
843 				janfirst += year_lengths[isleap(year)] *
844 					SECSPERDAY;
845 			}
846 		} else {
847 			register long	theirstdoffset;
848 			register long	theirdstoffset;
849 			register long	theiroffset;
850 			register int	isdst;
851 			register int	i;
852 			register int	j;
853 
854 			if (*name != '\0')
855 				return -1;
856 			if (load_result != 0)
857 				return -1;
858 			/*
859 			** Initial values of theirstdoffset and theirdstoffset.
860 			*/
861 			theirstdoffset = 0;
862 			for (i = 0; i < sp->timecnt; ++i) {
863 				j = sp->types[i];
864 				if (!sp->ttis[j].tt_isdst) {
865 					theirstdoffset =
866 						-sp->ttis[j].tt_gmtoff;
867 					break;
868 				}
869 			}
870 			theirdstoffset = 0;
871 			for (i = 0; i < sp->timecnt; ++i) {
872 				j = sp->types[i];
873 				if (sp->ttis[j].tt_isdst) {
874 					theirdstoffset =
875 						-sp->ttis[j].tt_gmtoff;
876 					break;
877 				}
878 			}
879 			/*
880 			** Initially we're assumed to be in standard time.
881 			*/
882 			isdst = FALSE;
883 			theiroffset = theirstdoffset;
884 			/*
885 			** Now juggle transition times and types
886 			** tracking offsets as you do.
887 			*/
888 			for (i = 0; i < sp->timecnt; ++i) {
889 				j = sp->types[i];
890 				sp->types[i] = sp->ttis[j].tt_isdst;
891 				if (sp->ttis[j].tt_ttisgmt) {
892 					/* No adjustment to transition time */
893 				} else {
894 					/*
895 					** If summer time is in effect, and the
896 					** transition time was not specified as
897 					** standard time, add the summer time
898 					** offset to the transition time;
899 					** otherwise, add the standard time
900 					** offset to the transition time.
901 					*/
902 					/*
903 					** Transitions from DST to DDST
904 					** will effectively disappear since
905 					** POSIX provides for only one DST
906 					** offset.
907 					*/
908 					if (isdst && !sp->ttis[j].tt_ttisstd) {
909 						sp->ats[i] += dstoffset -
910 							theirdstoffset;
911 					} else {
912 						sp->ats[i] += stdoffset -
913 							theirstdoffset;
914 					}
915 				}
916 				theiroffset = -sp->ttis[j].tt_gmtoff;
917 				if (sp->ttis[j].tt_isdst)
918 					theirdstoffset = theiroffset;
919 				else	theirstdoffset = theiroffset;
920 			}
921 			/*
922 			** Finally, fill in ttis.
923 			** ttisstd and ttisgmt need not be handled.
924 			*/
925 			sp->ttis[0].tt_gmtoff = -stdoffset;
926 			sp->ttis[0].tt_isdst = FALSE;
927 			sp->ttis[0].tt_abbrind = 0;
928 			sp->ttis[1].tt_gmtoff = -dstoffset;
929 			sp->ttis[1].tt_isdst = TRUE;
930 			sp->ttis[1].tt_abbrind = stdlen + 1;
931 			sp->typecnt = 2;
932 		}
933 	} else {
934 		dstlen = 0;
935 		sp->typecnt = 1;		/* only standard time */
936 		sp->timecnt = 0;
937 		sp->ttis[0].tt_gmtoff = -stdoffset;
938 		sp->ttis[0].tt_isdst = 0;
939 		sp->ttis[0].tt_abbrind = 0;
940 	}
941 	sp->charcnt = stdlen + 1;
942 	if (dstlen != 0)
943 		sp->charcnt += dstlen + 1;
944 	if ((size_t) sp->charcnt > sizeof sp->chars)
945 		return -1;
946 	cp = sp->chars;
947 	(void) strncpy(cp, stdname, stdlen);
948 	cp += stdlen;
949 	*cp++ = '\0';
950 	if (dstlen != 0) {
951 		(void) strncpy(cp, dstname, dstlen);
952 		*(cp + dstlen) = '\0';
953 	}
954 	return 0;
955 }
956 
957 static void
958 gmtload(sp)
959 struct state * const	sp;
960 {
961 	if (tzload(gmt, sp) != 0)
962 		(void) tzparse(gmt, sp, TRUE);
963 }
964 
965 static void
966 tzsetwall_unlocked P((void))
967 {
968 	if (lcl_is_set < 0)
969 		return;
970 	lcl_is_set = -1;
971 
972 #ifdef ALL_STATE
973 	if (lclptr == NULL) {
974 		lclptr = (struct state *) malloc(sizeof *lclptr);
975 		if (lclptr == NULL) {
976 			settzname();	/* all we can do */
977 			return;
978 		}
979 	}
980 #endif /* defined ALL_STATE */
981 	if (tzload((char *) NULL, lclptr) != 0)
982 		gmtload(lclptr);
983 	settzname();
984 }
985 
986 #ifndef STD_INSPIRED
987 /*
988 ** A non-static declaration of tzsetwall in a system header file
989 ** may cause a warning about this upcoming static declaration...
990 */
991 static
992 #endif /* !defined STD_INSPIRED */
993 void
994 tzsetwall P((void))
995 {
996 	rwlock_wrlock(&lcl_lock);
997 	tzsetwall_unlocked();
998 	rwlock_unlock(&lcl_lock);
999 }
1000 
1001 static void
1002 tzset_unlocked P((void))
1003 {
1004 	register const char *	name;
1005 
1006 	name = getenv("TZ");
1007 	if (name == NULL) {
1008 		tzsetwall_unlocked();
1009 		return;
1010 	}
1011 
1012 	if (lcl_is_set > 0  &&  strcmp(lcl_TZname, name) == 0)
1013 		return;
1014 	lcl_is_set = (strlen(name) < sizeof(lcl_TZname));
1015 	if (lcl_is_set)
1016 		(void)strncpy(lcl_TZname, name, sizeof(lcl_TZname) - 1);
1017 
1018 #ifdef ALL_STATE
1019 	if (lclptr == NULL) {
1020 		lclptr = (struct state *) malloc(sizeof *lclptr);
1021 		if (lclptr == NULL) {
1022 			settzname();	/* all we can do */
1023 			return;
1024 		}
1025 	}
1026 #endif /* defined ALL_STATE */
1027 	if (*name == '\0') {
1028 		/*
1029 		** User wants it fast rather than right.
1030 		*/
1031 		lclptr->leapcnt = 0;		/* so, we're off a little */
1032 		lclptr->timecnt = 0;
1033 		lclptr->ttis[0].tt_gmtoff = 0;
1034 		lclptr->ttis[0].tt_abbrind = 0;
1035 		(void)strncpy(lclptr->chars, gmt, sizeof(lclptr->chars) - 1);
1036 	} else if (tzload(name, lclptr) != 0)
1037 		if (name[0] == ':' || tzparse(name, lclptr, FALSE) != 0)
1038 			(void) gmtload(lclptr);
1039 	settzname();
1040 }
1041 
1042 void
1043 tzset P((void))
1044 {
1045 	rwlock_wrlock(&lcl_lock);
1046 	tzset_unlocked();
1047 	rwlock_unlock(&lcl_lock);
1048 }
1049 
1050 /*
1051 ** The easy way to behave "as if no library function calls" localtime
1052 ** is to not call it--so we drop its guts into "localsub", which can be
1053 ** freely called.  (And no, the PANS doesn't require the above behavior--
1054 ** but it *is* desirable.)
1055 **
1056 ** The unused offset argument is for the benefit of mktime variants.
1057 */
1058 
1059 /*ARGSUSED*/
1060 static void
1061 localsub(timep, offset, tmp)
1062 const time_t * const	timep;
1063 const long		offset;
1064 struct tm * const	tmp;
1065 {
1066 	register struct state *		sp;
1067 	register const struct ttinfo *	ttisp;
1068 	register int			i;
1069 	const time_t			t = *timep;
1070 
1071 	sp = lclptr;
1072 #ifdef ALL_STATE
1073 	if (sp == NULL) {
1074 		gmtsub(timep, offset, tmp);
1075 		return;
1076 	}
1077 #endif /* defined ALL_STATE */
1078 	if (sp->timecnt == 0 || t < sp->ats[0]) {
1079 		i = 0;
1080 		while (sp->ttis[i].tt_isdst)
1081 			if (++i >= sp->typecnt) {
1082 				i = 0;
1083 				break;
1084 			}
1085 	} else {
1086 		for (i = 1; i < sp->timecnt; ++i)
1087 			if (t < sp->ats[i])
1088 				break;
1089 		i = sp->types[i - 1];
1090 	}
1091 	ttisp = &sp->ttis[i];
1092 	/*
1093 	** To get (wrong) behavior that's compatible with System V Release 2.0
1094 	** you'd replace the statement below with
1095 	**	t += ttisp->tt_gmtoff;
1096 	**	timesub(&t, 0L, sp, tmp);
1097 	*/
1098 	timesub(&t, ttisp->tt_gmtoff, sp, tmp);
1099 	tmp->tm_isdst = ttisp->tt_isdst;
1100 	tzname[tmp->tm_isdst] = &sp->chars[ttisp->tt_abbrind];
1101 #ifdef TM_ZONE
1102 	tmp->TM_ZONE = &sp->chars[ttisp->tt_abbrind];
1103 #endif /* defined TM_ZONE */
1104 }
1105 
1106 struct tm *
1107 localtime(timep)
1108 const time_t * const	timep;
1109 {
1110 	rwlock_wrlock(&lcl_lock);
1111 	tzset_unlocked();
1112 	localsub(timep, 0L, &tm);
1113 	rwlock_unlock(&lcl_lock);
1114 	return &tm;
1115 }
1116 
1117 /*
1118  * Re-entrant version of localtime
1119  */
1120 struct tm *
1121 localtime_r(timep, tm)
1122 const time_t * const	timep;
1123 struct tm *		tm;
1124 {
1125 	rwlock_rdlock(&lcl_lock);
1126 	localsub(timep, 0L, tm);
1127 	rwlock_unlock(&lcl_lock);
1128 	return tm;
1129 }
1130 
1131 /*
1132 ** gmtsub is to gmtime as localsub is to localtime.
1133 */
1134 
1135 static void
1136 gmtsub(timep, offset, tmp)
1137 const time_t * const	timep;
1138 const long		offset;
1139 struct tm * const	tmp;
1140 {
1141 #ifdef _REENT
1142 	static mutex_t gmt_mutex = MUTEX_INITIALIZER;
1143 #endif
1144 
1145 	mutex_lock(&gmt_mutex);
1146 	if (!gmt_is_set) {
1147 		gmt_is_set = TRUE;
1148 #ifdef ALL_STATE
1149 		gmtptr = (struct state *) malloc(sizeof *gmtptr);
1150 		if (gmtptr != NULL)
1151 #endif /* defined ALL_STATE */
1152 			gmtload(gmtptr);
1153 	}
1154 	mutex_unlock(&gmt_mutex);
1155 	timesub(timep, offset, gmtptr, tmp);
1156 #ifdef TM_ZONE
1157 	/*
1158 	** Could get fancy here and deliver something such as
1159 	** "UTC+xxxx" or "UTC-xxxx" if offset is non-zero,
1160 	** but this is no time for a treasure hunt.
1161 	*/
1162 	if (offset != 0)
1163 		/* LINTED const castaway */
1164 		tmp->TM_ZONE = (__aconst char *)wildabbr;
1165 	else {
1166 #ifdef ALL_STATE
1167 		if (gmtptr == NULL)
1168 			tmp->TM_ZONE = (__aconst char *)gmt;
1169 		else	tmp->TM_ZONE = gmtptr->chars;
1170 #endif /* defined ALL_STATE */
1171 #ifndef ALL_STATE
1172 		tmp->TM_ZONE = gmtptr->chars;
1173 #endif /* State Farm */
1174 	}
1175 #endif /* defined TM_ZONE */
1176 }
1177 
1178 struct tm *
1179 gmtime(timep)
1180 const time_t * const	timep;
1181 {
1182 	gmtsub(timep, 0L, &tm);
1183 	return &tm;
1184 }
1185 
1186 /*
1187  * Re-entrant version of gmtime
1188  */
1189 struct tm *
1190 gmtime_r(timep, tm)
1191 const time_t * const	timep;
1192 struct tm *		tm;
1193 {
1194 	gmtsub(timep, 0L, tm);
1195 	return tm;
1196 }
1197 
1198 #ifdef STD_INSPIRED
1199 
1200 struct tm *
1201 offtime(timep, offset)
1202 const time_t * const	timep;
1203 const long		offset;
1204 {
1205 	gmtsub(timep, offset, &tm);
1206 	return &tm;
1207 }
1208 
1209 #endif /* defined STD_INSPIRED */
1210 
1211 static void
1212 timesub(timep, offset, sp, tmp)
1213 const time_t * const			timep;
1214 const long				offset;
1215 register const struct state * const	sp;
1216 register struct tm * const		tmp;
1217 {
1218 	register const struct lsinfo *	lp;
1219 	register long			days;
1220 	register long			rem;
1221 	register int			y;
1222 	register int			yleap;
1223 	register const int *		ip;
1224 	register long			corr;
1225 	register int			hit;
1226 	register int			i;
1227 
1228 	corr = 0;
1229 	hit = 0;
1230 #ifdef ALL_STATE
1231 	i = (sp == NULL) ? 0 : sp->leapcnt;
1232 #endif /* defined ALL_STATE */
1233 #ifndef ALL_STATE
1234 	i = sp->leapcnt;
1235 #endif /* State Farm */
1236 	while (--i >= 0) {
1237 		lp = &sp->lsis[i];
1238 		if (*timep >= lp->ls_trans) {
1239 			if (*timep == lp->ls_trans) {
1240 				hit = ((i == 0 && lp->ls_corr > 0) ||
1241 					lp->ls_corr > sp->lsis[i - 1].ls_corr);
1242 				if (hit)
1243 					while (i > 0 &&
1244 						sp->lsis[i].ls_trans ==
1245 						sp->lsis[i - 1].ls_trans + 1 &&
1246 						sp->lsis[i].ls_corr ==
1247 						sp->lsis[i - 1].ls_corr + 1) {
1248 							++hit;
1249 							--i;
1250 					}
1251 			}
1252 			corr = lp->ls_corr;
1253 			break;
1254 		}
1255 	}
1256 	days = *timep / SECSPERDAY;
1257 	rem = *timep % SECSPERDAY;
1258 #ifdef mc68k
1259 	if (*timep == 0x80000000) {
1260 		/*
1261 		** A 3B1 muffs the division on the most negative number.
1262 		*/
1263 		days = -24855;
1264 		rem = -11648;
1265 	}
1266 #endif /* defined mc68k */
1267 	rem += (offset - corr);
1268 	while (rem < 0) {
1269 		rem += SECSPERDAY;
1270 		--days;
1271 	}
1272 	while (rem >= SECSPERDAY) {
1273 		rem -= SECSPERDAY;
1274 		++days;
1275 	}
1276 	tmp->tm_hour = (int) (rem / SECSPERHOUR);
1277 	rem = rem % SECSPERHOUR;
1278 	tmp->tm_min = (int) (rem / SECSPERMIN);
1279 	/*
1280 	** A positive leap second requires a special
1281 	** representation.  This uses "... ??:59:60" et seq.
1282 	*/
1283 	tmp->tm_sec = (int) (rem % SECSPERMIN) + hit;
1284 	tmp->tm_wday = (int) ((EPOCH_WDAY + days) % DAYSPERWEEK);
1285 	if (tmp->tm_wday < 0)
1286 		tmp->tm_wday += DAYSPERWEEK;
1287 	y = EPOCH_YEAR;
1288 #define LEAPS_THRU_END_OF(y)	((y) / 4 - (y) / 100 + (y) / 400)
1289 	while (days < 0 || days >= (long) year_lengths[yleap = isleap(y)]) {
1290 		register int	newy;
1291 
1292 		newy = (int)(y + days / DAYSPERNYEAR);
1293 		if (days < 0)
1294 			--newy;
1295 		days -= (newy - y) * DAYSPERNYEAR +
1296 			LEAPS_THRU_END_OF(newy - 1) -
1297 			LEAPS_THRU_END_OF(y - 1);
1298 		y = newy;
1299 	}
1300 	tmp->tm_year = y - TM_YEAR_BASE;
1301 	tmp->tm_yday = (int) days;
1302 	ip = mon_lengths[yleap];
1303 	for (tmp->tm_mon = 0; days >= (long) ip[tmp->tm_mon]; ++(tmp->tm_mon))
1304 		days = days - (long) ip[tmp->tm_mon];
1305 	tmp->tm_mday = (int) (days + 1);
1306 	tmp->tm_isdst = 0;
1307 #ifdef TM_GMTOFF
1308 	tmp->TM_GMTOFF = offset;
1309 #endif /* defined TM_GMTOFF */
1310 }
1311 
1312 char *
1313 ctime(timep)
1314 const time_t * const	timep;
1315 {
1316 /*
1317 ** Section 4.12.3.2 of X3.159-1989 requires that
1318 **	The ctime function converts the calendar time pointed to by timer
1319 **	to local time in the form of a string.  It is equivalent to
1320 **		asctime(localtime(timer))
1321 */
1322 	return asctime(localtime(timep));
1323 }
1324 
1325 char *
1326 ctime_r(timep, buf)
1327 const time_t * const	timep;
1328 char *			buf;
1329 {
1330 	struct tm	tmp;
1331 
1332 	return asctime_r(localtime_r(timep, &tmp), buf);
1333 }
1334 
1335 /*
1336 ** Adapted from code provided by Robert Elz, who writes:
1337 **	The "best" way to do mktime I think is based on an idea of Bob
1338 **	Kridle's (so its said...) from a long time ago.
1339 **	[kridle@xinet.com as of 1996-01-16.]
1340 **	It does a binary search of the time_t space.  Since time_t's are
1341 **	just 32 bits, its a max of 32 iterations (even at 64 bits it
1342 **	would still be very reasonable).
1343 */
1344 
1345 #ifndef WRONG
1346 #define WRONG	(-1)
1347 #endif /* !defined WRONG */
1348 
1349 /*
1350 ** Simplified normalize logic courtesy Paul Eggert (eggert@twinsun.com).
1351 */
1352 
1353 static int
1354 increment_overflow(number, delta)
1355 int *	number;
1356 int	delta;
1357 {
1358 	int	number0;
1359 
1360 	number0 = *number;
1361 	*number += delta;
1362 	return (*number < number0) != (delta < 0);
1363 }
1364 
1365 static int
1366 normalize_overflow(tensptr, unitsptr, base)
1367 int * const	tensptr;
1368 int * const	unitsptr;
1369 const int	base;
1370 {
1371 	register int	tensdelta;
1372 
1373 	tensdelta = (*unitsptr >= 0) ?
1374 		(*unitsptr / base) :
1375 		(-1 - (-1 - *unitsptr) / base);
1376 	*unitsptr -= tensdelta * base;
1377 	return increment_overflow(tensptr, tensdelta);
1378 }
1379 
1380 static int
1381 tmcomp(atmp, btmp)
1382 register const struct tm * const atmp;
1383 register const struct tm * const btmp;
1384 {
1385 	register int	result;
1386 
1387 	if ((result = (atmp->tm_year - btmp->tm_year)) == 0 &&
1388 		(result = (atmp->tm_mon - btmp->tm_mon)) == 0 &&
1389 		(result = (atmp->tm_mday - btmp->tm_mday)) == 0 &&
1390 		(result = (atmp->tm_hour - btmp->tm_hour)) == 0 &&
1391 		(result = (atmp->tm_min - btmp->tm_min)) == 0)
1392 			result = atmp->tm_sec - btmp->tm_sec;
1393 	return result;
1394 }
1395 
1396 static time_t
1397 time2sub(tmp, funcp, offset, okayp, do_norm_secs)
1398 struct tm * const	tmp;
1399 void (* const		funcp) P((const time_t*, long, struct tm*));
1400 const long		offset;
1401 int * const		okayp;
1402 const int		do_norm_secs;
1403 {
1404 	register const struct state *	sp;
1405 	register int			dir;
1406 	register int			bits;
1407 	register int			i, j ;
1408 	register int			saved_seconds;
1409 	time_t				newt;
1410 	time_t				t;
1411 	struct tm			yourtm, mytm;
1412 
1413 	*okayp = FALSE;
1414 	yourtm = *tmp;
1415 	if (do_norm_secs) {
1416 		if (normalize_overflow(&yourtm.tm_min, &yourtm.tm_sec,
1417 			SECSPERMIN))
1418 				return WRONG;
1419 	}
1420 	if (normalize_overflow(&yourtm.tm_hour, &yourtm.tm_min, MINSPERHOUR))
1421 		return WRONG;
1422 	if (normalize_overflow(&yourtm.tm_mday, &yourtm.tm_hour, HOURSPERDAY))
1423 		return WRONG;
1424 	if (normalize_overflow(&yourtm.tm_year, &yourtm.tm_mon, MONSPERYEAR))
1425 		return WRONG;
1426 	/*
1427 	** Turn yourtm.tm_year into an actual year number for now.
1428 	** It is converted back to an offset from TM_YEAR_BASE later.
1429 	*/
1430 	if (increment_overflow(&yourtm.tm_year, TM_YEAR_BASE))
1431 		return WRONG;
1432 	while (yourtm.tm_mday <= 0) {
1433 		if (increment_overflow(&yourtm.tm_year, -1))
1434 			return WRONG;
1435 		i = yourtm.tm_year + (1 < yourtm.tm_mon);
1436 		yourtm.tm_mday += year_lengths[isleap(i)];
1437 	}
1438 	while (yourtm.tm_mday > DAYSPERLYEAR) {
1439 		i = yourtm.tm_year + (1 < yourtm.tm_mon);
1440 		yourtm.tm_mday -= year_lengths[isleap(i)];
1441 		if (increment_overflow(&yourtm.tm_year, 1))
1442 			return WRONG;
1443 	}
1444 	for ( ; ; ) {
1445 		i = mon_lengths[isleap(yourtm.tm_year)][yourtm.tm_mon];
1446 		if (yourtm.tm_mday <= i)
1447 			break;
1448 		yourtm.tm_mday -= i;
1449 		if (++yourtm.tm_mon >= MONSPERYEAR) {
1450 			yourtm.tm_mon = 0;
1451 			if (increment_overflow(&yourtm.tm_year, 1))
1452 				return WRONG;
1453 		}
1454 	}
1455 	if (increment_overflow(&yourtm.tm_year, -TM_YEAR_BASE))
1456 		return WRONG;
1457 	if (yourtm.tm_year + TM_YEAR_BASE < EPOCH_YEAR) {
1458 		/*
1459 		** We can't set tm_sec to 0, because that might push the
1460 		** time below the minimum representable time.
1461 		** Set tm_sec to 59 instead.
1462 		** This assumes that the minimum representable time is
1463 		** not in the same minute that a leap second was deleted from,
1464 		** which is a safer assumption than using 58 would be.
1465 		*/
1466 		if (increment_overflow(&yourtm.tm_sec, 1 - SECSPERMIN))
1467 			return WRONG;
1468 		saved_seconds = yourtm.tm_sec;
1469 		yourtm.tm_sec = SECSPERMIN - 1;
1470 	} else {
1471 		saved_seconds = yourtm.tm_sec;
1472 		yourtm.tm_sec = 0;
1473 	}
1474 	/*
1475 	** Divide the search space in half
1476 	** (this works whether time_t is signed or unsigned).
1477 	*/
1478 	bits = TYPE_BIT(time_t) - 1;
1479 	/*
1480 	** If time_t is signed, then 0 is just above the median,
1481 	** assuming two's complement arithmetic.
1482 	** If time_t is unsigned, then (1 << bits) is just above the median.
1483 	*/
1484 	/* LINTED constant in conditional context */
1485 	t = TYPE_SIGNED(time_t) ? 0 : (((time_t) 1) << bits);
1486 	for ( ; ; ) {
1487 		(*funcp)(&t, offset, &mytm);
1488 		dir = tmcomp(&mytm, &yourtm);
1489 		if (dir != 0) {
1490 			if (bits-- < 0)
1491 				return WRONG;
1492 			if (bits < 0)
1493 				--t; /* may be needed if new t is minimal */
1494 			else if (dir > 0)
1495 				t -= ((time_t) 1) << bits;
1496 			else	t += ((time_t) 1) << bits;
1497 			continue;
1498 		}
1499 		if (yourtm.tm_isdst < 0 || mytm.tm_isdst == yourtm.tm_isdst)
1500 			break;
1501 		/*
1502 		** Right time, wrong type.
1503 		** Hunt for right time, right type.
1504 		** It's okay to guess wrong since the guess
1505 		** gets checked.
1506 		*/
1507 		/*
1508 		** The (void *) casts are the benefit of SunOS 3.3 on Sun 2's.
1509 		*/
1510 		sp = (const struct state *)
1511 			(((void *) funcp == (void *) localsub) ?
1512 			lclptr : gmtptr);
1513 #ifdef ALL_STATE
1514 		if (sp == NULL)
1515 			return WRONG;
1516 #endif /* defined ALL_STATE */
1517 		for (i = sp->typecnt - 1; i >= 0; --i) {
1518 			if (sp->ttis[i].tt_isdst != yourtm.tm_isdst)
1519 				continue;
1520 			for (j = sp->typecnt - 1; j >= 0; --j) {
1521 				if (sp->ttis[j].tt_isdst == yourtm.tm_isdst)
1522 					continue;
1523 				newt = t + sp->ttis[j].tt_gmtoff -
1524 					sp->ttis[i].tt_gmtoff;
1525 				(*funcp)(&newt, offset, &mytm);
1526 				if (tmcomp(&mytm, &yourtm) != 0)
1527 					continue;
1528 				if (mytm.tm_isdst != yourtm.tm_isdst)
1529 					continue;
1530 				/*
1531 				** We have a match.
1532 				*/
1533 				t = newt;
1534 				goto label;
1535 			}
1536 		}
1537 		return WRONG;
1538 	}
1539 label:
1540 	newt = t + saved_seconds;
1541 	if ((newt < t) != (saved_seconds < 0))
1542 		return WRONG;
1543 	t = newt;
1544 	(*funcp)(&t, offset, tmp);
1545 	*okayp = TRUE;
1546 	return t;
1547 }
1548 
1549 static time_t
1550 time2(tmp, funcp, offset, okayp)
1551 struct tm * const	tmp;
1552 void (* const		funcp) P((const time_t*, long, struct tm*));
1553 const long		offset;
1554 int * const		okayp;
1555 {
1556 	time_t	t;
1557 
1558 	/*
1559 	** First try without normalization of seconds
1560 	** (in case tm_sec contains a value associated with a leap second).
1561 	** If that fails, try with normalization of seconds.
1562 	*/
1563 	t = time2sub(tmp, funcp, offset, okayp, FALSE);
1564 	return *okayp ? t : time2sub(tmp, funcp, offset, okayp, TRUE);
1565 }
1566 
1567 static time_t
1568 time1(tmp, funcp, offset)
1569 struct tm * const	tmp;
1570 void (* const		funcp) P((const time_t *, long, struct tm *));
1571 const long		offset;
1572 {
1573 	register time_t			t;
1574 	register const struct state *	sp;
1575 	register int			samei, otheri;
1576 	int				okay;
1577 
1578 	if (tmp->tm_isdst > 1)
1579 		tmp->tm_isdst = 1;
1580 	t = time2(tmp, funcp, offset, &okay);
1581 #ifdef PCTS
1582 	/*
1583 	** PCTS code courtesy Grant Sullivan (grant@osf.org).
1584 	*/
1585 	if (okay)
1586 		return t;
1587 	if (tmp->tm_isdst < 0)
1588 		tmp->tm_isdst = 0;	/* reset to std and try again */
1589 #endif /* defined PCTS */
1590 #ifndef PCTS
1591 	if (okay || tmp->tm_isdst < 0)
1592 		return t;
1593 #endif /* !defined PCTS */
1594 	/*
1595 	** We're supposed to assume that somebody took a time of one type
1596 	** and did some math on it that yielded a "struct tm" that's bad.
1597 	** We try to divine the type they started from and adjust to the
1598 	** type they need.
1599 	*/
1600 	/*
1601 	** The (void *) casts are the benefit of SunOS 3.3 on Sun 2's.
1602 	*/
1603 	sp = (const struct state *) (((void *) funcp == (void *) localsub) ?
1604 		lclptr : gmtptr);
1605 #ifdef ALL_STATE
1606 	if (sp == NULL)
1607 		return WRONG;
1608 #endif /* defined ALL_STATE */
1609 	for (samei = sp->typecnt - 1; samei >= 0; --samei) {
1610 		if (sp->ttis[samei].tt_isdst != tmp->tm_isdst)
1611 			continue;
1612 		for (otheri = sp->typecnt - 1; otheri >= 0; --otheri) {
1613 			if (sp->ttis[otheri].tt_isdst == tmp->tm_isdst)
1614 				continue;
1615 			tmp->tm_sec += (int)(sp->ttis[otheri].tt_gmtoff -
1616 					sp->ttis[samei].tt_gmtoff);
1617 			tmp->tm_isdst = !tmp->tm_isdst;
1618 			t = time2(tmp, funcp, offset, &okay);
1619 			if (okay)
1620 				return t;
1621 			tmp->tm_sec -= (int)(sp->ttis[otheri].tt_gmtoff -
1622 					sp->ttis[samei].tt_gmtoff);
1623 			tmp->tm_isdst = !tmp->tm_isdst;
1624 		}
1625 	}
1626 	return WRONG;
1627 }
1628 
1629 time_t
1630 mktime(tmp)
1631 struct tm * const	tmp;
1632 {
1633 	time_t result;
1634 
1635 	rwlock_wrlock(&lcl_lock);
1636 	tzset_unlocked();
1637 	result = time1(tmp, localsub, 0L);
1638 	rwlock_unlock(&lcl_lock);
1639 	return (result);
1640 }
1641 
1642 #ifdef STD_INSPIRED
1643 
1644 time_t
1645 timelocal(tmp)
1646 struct tm * const	tmp;
1647 {
1648 	tmp->tm_isdst = -1;	/* in case it wasn't initialized */
1649 	return mktime(tmp);
1650 }
1651 
1652 time_t
1653 timegm(tmp)
1654 struct tm * const	tmp;
1655 {
1656 	tmp->tm_isdst = 0;
1657 	return time1(tmp, gmtsub, 0L);
1658 }
1659 
1660 time_t
1661 timeoff(tmp, offset)
1662 struct tm * const	tmp;
1663 const long		offset;
1664 {
1665 	tmp->tm_isdst = 0;
1666 	return time1(tmp, gmtsub, offset);
1667 }
1668 
1669 #endif /* defined STD_INSPIRED */
1670 
1671 #ifdef CMUCS
1672 
1673 /*
1674 ** The following is supplied for compatibility with
1675 ** previous versions of the CMUCS runtime library.
1676 */
1677 
1678 long
1679 gtime(tmp)
1680 struct tm * const	tmp;
1681 {
1682 	const time_t	t = mktime(tmp);
1683 
1684 	if (t == WRONG)
1685 		return -1;
1686 	return t;
1687 }
1688 
1689 #endif /* defined CMUCS */
1690 
1691 /*
1692 ** XXX--is the below the right way to conditionalize??
1693 */
1694 
1695 #ifdef STD_INSPIRED
1696 
1697 /*
1698 ** IEEE Std 1003.1-1988 (POSIX) legislates that 536457599
1699 ** shall correspond to "Wed Dec 31 23:59:59 UTC 1986", which
1700 ** is not the case if we are accounting for leap seconds.
1701 ** So, we provide the following conversion routines for use
1702 ** when exchanging timestamps with POSIX conforming systems.
1703 */
1704 
1705 static long
1706 leapcorr(timep)
1707 time_t *	timep;
1708 {
1709 	register struct state *		sp;
1710 	register struct lsinfo *	lp;
1711 	register int			i;
1712 
1713 	sp = lclptr;
1714 	i = sp->leapcnt;
1715 	while (--i >= 0) {
1716 		lp = &sp->lsis[i];
1717 		if (*timep >= lp->ls_trans)
1718 			return lp->ls_corr;
1719 	}
1720 	return 0;
1721 }
1722 
1723 time_t
1724 time2posix(t)
1725 time_t	t;
1726 {
1727 	time_t result;
1728 
1729 	rwlock_wrlock(&lcl_lock);
1730 	tzset_unlocked();
1731 	result = t - leapcorr(&t);
1732 	rwlock_unlock(&lcl_lock);
1733 	return (result);
1734 }
1735 
1736 time_t
1737 posix2time(t)
1738 time_t	t;
1739 {
1740 	time_t	x;
1741 	time_t	y;
1742 
1743 	rwlock_wrlock(&lcl_lock);
1744 	tzset_unlocked();
1745 	/*
1746 	** For a positive leap second hit, the result
1747 	** is not unique.  For a negative leap second
1748 	** hit, the corresponding time doesn't exist,
1749 	** so we return an adjacent second.
1750 	*/
1751 	x = t + leapcorr(&t);
1752 	y = x - leapcorr(&x);
1753 	if (y < t) {
1754 		do {
1755 			x++;
1756 			y = x - leapcorr(&x);
1757 		} while (y < t);
1758 		if (t != y) {
1759 			rwlock_unlock(&lcl_lock);
1760 			return x - 1;
1761 		}
1762 	} else if (y > t) {
1763 		do {
1764 			--x;
1765 			y = x - leapcorr(&x);
1766 		} while (y > t);
1767 		if (t != y) {
1768 			rwlock_unlock(&lcl_lock);
1769 			return x + 1;
1770 		}
1771 	}
1772 	rwlock_unlock(&lcl_lock);
1773 	return x;
1774 }
1775 
1776 #endif /* defined STD_INSPIRED */
1777