localtime.c revision 17706
1/*
2** This file is in the public domain, so clarified as of
3** June 5, 1996 by Arthur David Olson (arthur_david_olson@nih.gov).
4*/
5
6#ifndef lint
7#ifndef NOID
8static char	elsieid[] = "@(#)localtime.c	7.57";
9#endif /* !defined NOID */
10#endif /* !defined lint */
11
12/*
13** Leap second handling from Bradley White (bww@k.gp.cs.cmu.edu).
14** POSIX-style TZ environment variable handling from Guy Harris
15** (guy@auspex.com).
16*/
17
18/*LINTLIBRARY*/
19
20#include "private.h"
21#include "tzfile.h"
22#include "fcntl.h"
23#ifdef	_THREAD_SAFE
24#include <pthread.h>
25#include "pthread_private.h"
26#endif
27
28/*
29** SunOS 4.1.1 headers lack O_BINARY.
30*/
31
32#ifdef O_BINARY
33#define OPEN_MODE	(O_RDONLY | O_BINARY)
34#endif /* defined O_BINARY */
35#ifndef O_BINARY
36#define OPEN_MODE	O_RDONLY
37#endif /* !defined O_BINARY */
38
39#ifndef WILDABBR
40/*
41** Someone might make incorrect use of a time zone abbreviation:
42**	1.	They might reference tzname[0] before calling tzset (explicitly
43**		or implicitly).
44**	2.	They might reference tzname[1] before calling tzset (explicitly
45**		or implicitly).
46**	3.	They might reference tzname[1] after setting to a time zone
47**		in which Daylight Saving Time is never observed.
48**	4.	They might reference tzname[0] after setting to a time zone
49**		in which Standard Time is never observed.
50**	5.	They might reference tm.TM_ZONE after calling offtime.
51** What's best to do in the above cases is open to debate;
52** for now, we just set things up so that in any of the five cases
53** WILDABBR is used.  Another possibility:  initialize tzname[0] to the
54** string "tzname[0] used before set", and similarly for the other cases.
55** And another:  initialize tzname[0] to "ERA", with an explanation in the
56** manual page of what this "time zone abbreviation" means (doing this so
57** that tzname[0] has the "normal" length of three characters).
58*/
59#define WILDABBR	"   "
60#endif /* !defined WILDABBR */
61
62static char		wildabbr[] = "WILDABBR";
63
64static const char	gmt[] = "GMT";
65
66struct ttinfo {				/* time type information */
67	long		tt_gmtoff;	/* GMT offset in seconds */
68	int		tt_isdst;	/* used to set tm_isdst */
69	int		tt_abbrind;	/* abbreviation list index */
70	int		tt_ttisstd;	/* TRUE if transition is std time */
71	int		tt_ttisgmt;	/* TRUE if transition is GMT */
72};
73
74struct lsinfo {				/* leap second information */
75	time_t		ls_trans;	/* transition time */
76	long		ls_corr;	/* correction to apply */
77};
78
79#define BIGGEST(a, b)	(((a) > (b)) ? (a) : (b))
80
81#ifdef TZNAME_MAX
82#define MY_TZNAME_MAX	TZNAME_MAX
83#endif /* defined TZNAME_MAX */
84#ifndef TZNAME_MAX
85#define MY_TZNAME_MAX	255
86#endif /* !defined TZNAME_MAX */
87
88struct state {
89	int		leapcnt;
90	int		timecnt;
91	int		typecnt;
92	int		charcnt;
93	time_t		ats[TZ_MAX_TIMES];
94	unsigned char	types[TZ_MAX_TIMES];
95	struct ttinfo	ttis[TZ_MAX_TYPES];
96	char		chars[BIGGEST(BIGGEST(TZ_MAX_CHARS + 1, sizeof gmt),
97				(2 * (MY_TZNAME_MAX + 1)))];
98	struct lsinfo	lsis[TZ_MAX_LEAPS];
99};
100
101struct rule {
102	int		r_type;		/* type of rule--see below */
103	int		r_day;		/* day number of rule */
104	int		r_week;		/* week number of rule */
105	int		r_mon;		/* month number of rule */
106	long		r_time;		/* transition time of rule */
107};
108
109#define JULIAN_DAY		0	/* Jn - Julian day */
110#define DAY_OF_YEAR		1	/* n - day of year */
111#define MONTH_NTH_DAY_OF_WEEK	2	/* Mm.n.d - month, week, day of week */
112
113/*
114** Prototypes for static functions.
115*/
116
117static long		detzcode P((const char * codep));
118static const char *	getzname P((const char * strp));
119static const char *	getnum P((const char * strp, int * nump, int min,
120				int max));
121static const char *	getsecs P((const char * strp, long * secsp));
122static const char *	getoffset P((const char * strp, long * offsetp));
123static const char *	getrule P((const char * strp, struct rule * rulep));
124static void		gmtload P((struct state * sp));
125static void		gmtsub P((const time_t * timep, long offset,
126				struct tm * tmp));
127static void		localsub P((const time_t * timep, long offset,
128				struct tm * tmp));
129static int		increment_overflow P((int * number, int delta));
130static int		normalize_overflow P((int * tensptr, int * unitsptr,
131				int base));
132static void		settzname P((void));
133static time_t		time1 P((struct tm * tmp,
134				void(*funcp) P((const time_t *,
135				long, struct tm *)),
136				long offset));
137static time_t		time2 P((struct tm *tmp,
138				void(*funcp) P((const time_t *,
139				long, struct tm*)),
140				long offset, int * okayp));
141static void		timesub P((const time_t * timep, long offset,
142				const struct state * sp, struct tm * tmp));
143static int		tmcomp P((const struct tm * atmp,
144				const struct tm * btmp));
145static time_t		transtime P((time_t janfirst, int year,
146				const struct rule * rulep, long offset));
147static int		tzload P((const char * name, struct state * sp));
148static int		tzparse P((const char * name, struct state * sp,
149				int lastditch));
150
151#ifdef ALL_STATE
152static struct state *	lclptr;
153static struct state *	gmtptr;
154#endif /* defined ALL_STATE */
155
156#ifndef ALL_STATE
157static struct state	lclmem;
158static struct state	gmtmem;
159#define lclptr		(&lclmem)
160#define gmtptr		(&gmtmem)
161#endif /* State Farm */
162
163#ifndef TZ_STRLEN_MAX
164#define TZ_STRLEN_MAX 255
165#endif /* !defined TZ_STRLEN_MAX */
166
167static char		lcl_TZname[TZ_STRLEN_MAX + 1];
168static int		lcl_is_set;
169static int		gmt_is_set;
170#ifdef	_THREAD_SAFE
171static struct pthread_mutex	_lcl_mutexd = PTHREAD_MUTEX_INITIALIZER;
172static struct pthread_mutex	_gmt_mutexd = PTHREAD_MUTEX_INITIALIZER;
173static pthread_mutex_t		lcl_mutex   = &_lcl_mutexd;
174static pthread_mutex_t		gmt_mutex   = &_gmt_mutexd;
175#endif
176
177char *			tzname[2] = {
178	wildabbr,
179	wildabbr
180};
181
182/*
183** Section 4.12.3 of X3.159-1989 requires that
184**	Except for the strftime function, these functions [asctime,
185**	ctime, gmtime, localtime] return values in one of two static
186**	objects: a broken-down time structure and an array of char.
187** Thanks to Paul Eggert (eggert@twinsun.com) for noting this.
188*/
189
190static struct tm	tm;
191
192#ifdef USG_COMPAT
193time_t			timezone = 0;
194int			daylight = 0;
195#endif /* defined USG_COMPAT */
196
197#ifdef ALTZONE
198time_t			altzone = 0;
199#endif /* defined ALTZONE */
200
201static long
202detzcode(codep)
203const char * const	codep;
204{
205	register long	result;
206	register int	i;
207
208	result = (codep[0] & 0x80) ? ~0L : 0L;
209	for (i = 0; i < 4; ++i)
210		result = (result << 8) | (codep[i] & 0xff);
211	return result;
212}
213
214static void
215settzname P((void))
216{
217	register struct state * const	sp = lclptr;
218	register int			i;
219
220	tzname[0] = wildabbr;
221	tzname[1] = wildabbr;
222#ifdef USG_COMPAT
223	daylight = 0;
224	timezone = 0;
225#endif /* defined USG_COMPAT */
226#ifdef ALTZONE
227	altzone = 0;
228#endif /* defined ALTZONE */
229#ifdef ALL_STATE
230	if (sp == NULL) {
231		tzname[0] = tzname[1] = gmt;
232		return;
233	}
234#endif /* defined ALL_STATE */
235	for (i = 0; i < sp->typecnt; ++i) {
236		register const struct ttinfo * const	ttisp = &sp->ttis[i];
237
238		tzname[ttisp->tt_isdst] =
239			&sp->chars[ttisp->tt_abbrind];
240#ifdef USG_COMPAT
241		if (ttisp->tt_isdst)
242			daylight = 1;
243		if (i == 0 || !ttisp->tt_isdst)
244			timezone = -(ttisp->tt_gmtoff);
245#endif /* defined USG_COMPAT */
246#ifdef ALTZONE
247		if (i == 0 || ttisp->tt_isdst)
248			altzone = -(ttisp->tt_gmtoff);
249#endif /* defined ALTZONE */
250	}
251	/*
252	** And to get the latest zone names into tzname. . .
253	*/
254	for (i = 0; i < sp->timecnt; ++i) {
255		register const struct ttinfo * const	ttisp =
256							&sp->ttis[
257								sp->types[i]];
258
259		tzname[ttisp->tt_isdst] =
260			&sp->chars[ttisp->tt_abbrind];
261	}
262}
263
264static int
265tzload(name, sp)
266register const char *		name;
267register struct state * const	sp;
268{
269	register const char *	p;
270	register int		i;
271	register int		fid;
272
273	if (name == NULL && (name = TZDEFAULT) == NULL)
274		return -1;
275	{
276		register int	doaccess;
277		/*
278		** Section 4.9.1 of the C standard says that
279		** "FILENAME_MAX expands to an integral constant expression
280		** that is the sie needed for an array of char large enough
281		** to hold the longest file name string that the implementation
282		** guarantees can be opened."
283		*/
284		char		fullname[FILENAME_MAX + 1];
285
286		if (name[0] == ':')
287			++name;
288		doaccess = name[0] == '/';
289		if (!doaccess) {
290			if ((p = TZDIR) == NULL)
291				return -1;
292			if ((strlen(p) + strlen(name) + 1) >= sizeof fullname)
293				return -1;
294			(void) strcpy(fullname, p);
295			(void) strcat(fullname, "/");
296			(void) strcat(fullname, name);
297			/*
298			** Set doaccess if '.' (as in "../") shows up in name.
299			*/
300			if (strchr(name, '.') != NULL)
301				doaccess = TRUE;
302			name = fullname;
303		}
304		if (doaccess && access(name, R_OK) != 0)
305			return -1;
306		if ((fid = open(name, OPEN_MODE)) == -1)
307			return -1;
308	}
309	{
310		struct tzhead *	tzhp;
311		char		buf[sizeof *sp + sizeof *tzhp];
312		int		ttisstdcnt;
313		int		ttisgmtcnt;
314
315		i = read(fid, buf, sizeof buf);
316		if (close(fid) != 0)
317			return -1;
318		p = buf;
319		p += sizeof tzhp->tzh_reserved;
320		ttisstdcnt = (int) detzcode(p);
321		p += 4;
322		ttisgmtcnt = (int) detzcode(p);
323		p += 4;
324		sp->leapcnt = (int) detzcode(p);
325		p += 4;
326		sp->timecnt = (int) detzcode(p);
327		p += 4;
328		sp->typecnt = (int) detzcode(p);
329		p += 4;
330		sp->charcnt = (int) detzcode(p);
331		p += 4;
332		if (sp->leapcnt < 0 || sp->leapcnt > TZ_MAX_LEAPS ||
333			sp->typecnt <= 0 || sp->typecnt > TZ_MAX_TYPES ||
334			sp->timecnt < 0 || sp->timecnt > TZ_MAX_TIMES ||
335			sp->charcnt < 0 || sp->charcnt > TZ_MAX_CHARS ||
336			(ttisstdcnt != sp->typecnt && ttisstdcnt != 0) ||
337			(ttisgmtcnt != sp->typecnt && ttisgmtcnt != 0))
338				return -1;
339		if (i - (p - buf) < sp->timecnt * 4 +	/* ats */
340			sp->timecnt +			/* types */
341			sp->typecnt * (4 + 2) +		/* ttinfos */
342			sp->charcnt +			/* chars */
343			sp->leapcnt * (4 + 4) +		/* lsinfos */
344			ttisstdcnt +			/* ttisstds */
345			ttisgmtcnt)			/* ttisgmts */
346				return -1;
347		for (i = 0; i < sp->timecnt; ++i) {
348			sp->ats[i] = detzcode(p);
349			p += 4;
350		}
351		for (i = 0; i < sp->timecnt; ++i) {
352			sp->types[i] = (unsigned char) *p++;
353			if (sp->types[i] >= sp->typecnt)
354				return -1;
355		}
356		for (i = 0; i < sp->typecnt; ++i) {
357			register struct ttinfo *	ttisp;
358
359			ttisp = &sp->ttis[i];
360			ttisp->tt_gmtoff = detzcode(p);
361			p += 4;
362			ttisp->tt_isdst = (unsigned char) *p++;
363			if (ttisp->tt_isdst != 0 && ttisp->tt_isdst != 1)
364				return -1;
365			ttisp->tt_abbrind = (unsigned char) *p++;
366			if (ttisp->tt_abbrind < 0 ||
367				ttisp->tt_abbrind > sp->charcnt)
368					return -1;
369		}
370		for (i = 0; i < sp->charcnt; ++i)
371			sp->chars[i] = *p++;
372		sp->chars[i] = '\0';	/* ensure '\0' at end */
373		for (i = 0; i < sp->leapcnt; ++i) {
374			register struct lsinfo *	lsisp;
375
376			lsisp = &sp->lsis[i];
377			lsisp->ls_trans = detzcode(p);
378			p += 4;
379			lsisp->ls_corr = detzcode(p);
380			p += 4;
381		}
382		for (i = 0; i < sp->typecnt; ++i) {
383			register struct ttinfo *	ttisp;
384
385			ttisp = &sp->ttis[i];
386			if (ttisstdcnt == 0)
387				ttisp->tt_ttisstd = FALSE;
388			else {
389				ttisp->tt_ttisstd = *p++;
390				if (ttisp->tt_ttisstd != TRUE &&
391					ttisp->tt_ttisstd != FALSE)
392						return -1;
393			}
394		}
395		for (i = 0; i < sp->typecnt; ++i) {
396			register struct ttinfo *	ttisp;
397
398			ttisp = &sp->ttis[i];
399			if (ttisgmtcnt == 0)
400				ttisp->tt_ttisgmt = FALSE;
401			else {
402				ttisp->tt_ttisgmt = *p++;
403				if (ttisp->tt_ttisgmt != TRUE &&
404					ttisp->tt_ttisgmt != FALSE)
405						return -1;
406			}
407		}
408	}
409	return 0;
410}
411
412static const int	mon_lengths[2][MONSPERYEAR] = {
413	{ 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 },
414	{ 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }
415};
416
417static const int	year_lengths[2] = {
418	DAYSPERNYEAR, DAYSPERLYEAR
419};
420
421/*
422** Given a pointer into a time zone string, scan until a character that is not
423** a valid character in a zone name is found.  Return a pointer to that
424** character.
425*/
426
427static const char *
428getzname(strp)
429register const char *	strp;
430{
431	register char	c;
432
433	while ((c = *strp) != '\0' && !is_digit(c) && c != ',' && c != '-' &&
434		c != '+')
435			++strp;
436	return strp;
437}
438
439/*
440** Given a pointer into a time zone string, extract a number from that string.
441** Check that the number is within a specified range; if it is not, return
442** NULL.
443** Otherwise, return a pointer to the first character not part of the number.
444*/
445
446static const char *
447getnum(strp, nump, min, max)
448register const char *	strp;
449int * const		nump;
450const int		min;
451const int		max;
452{
453	register char	c;
454	register int	num;
455
456	if (strp == NULL || !is_digit(c = *strp))
457		return NULL;
458	num = 0;
459	do {
460		num = num * 10 + (c - '0');
461		if (num > max)
462			return NULL;	/* illegal value */
463		c = *++strp;
464	} while (is_digit(c));
465	if (num < min)
466		return NULL;		/* illegal value */
467	*nump = num;
468	return strp;
469}
470
471/*
472** Given a pointer into a time zone string, extract a number of seconds,
473** in hh[:mm[:ss]] form, from the string.
474** If any error occurs, return NULL.
475** Otherwise, return a pointer to the first character not part of the number
476** of seconds.
477*/
478
479static const char *
480getsecs(strp, secsp)
481register const char *	strp;
482long * const		secsp;
483{
484	int	num;
485
486	/*
487	** `HOURSPERDAY * DAYSPERWEEK - 1' allows quasi-Posix rules like
488	** "M10.4.6/26", which does not conform to Posix,
489	** but which specifies the equivalent of
490	** ``02:00 on the first Sunday on or after 23 Oct''.
491	*/
492	strp = getnum(strp, &num, 0, HOURSPERDAY * DAYSPERWEEK - 1);
493	if (strp == NULL)
494		return NULL;
495	*secsp = num * (long) SECSPERHOUR;
496	if (*strp == ':') {
497		++strp;
498		strp = getnum(strp, &num, 0, MINSPERHOUR - 1);
499		if (strp == NULL)
500			return NULL;
501		*secsp += num * SECSPERMIN;
502		if (*strp == ':') {
503			++strp;
504			/* `SECSPERMIN' allows for leap seconds.  */
505			strp = getnum(strp, &num, 0, SECSPERMIN);
506			if (strp == NULL)
507				return NULL;
508			*secsp += num;
509		}
510	}
511	return strp;
512}
513
514/*
515** Given a pointer into a time zone string, extract an offset, in
516** [+-]hh[:mm[:ss]] form, from the string.
517** If any error occurs, return NULL.
518** Otherwise, return a pointer to the first character not part of the time.
519*/
520
521static const char *
522getoffset(strp, offsetp)
523register const char *	strp;
524long * const		offsetp;
525{
526	register int	neg = 0;
527
528	if (*strp == '-') {
529		neg = 1;
530		++strp;
531	} else if (*strp == '+')
532		++strp;
533	strp = getsecs(strp, offsetp);
534	if (strp == NULL)
535		return NULL;		/* illegal time */
536	if (neg)
537		*offsetp = -*offsetp;
538	return strp;
539}
540
541/*
542** Given a pointer into a time zone string, extract a rule in the form
543** date[/time].  See POSIX section 8 for the format of "date" and "time".
544** If a valid rule is not found, return NULL.
545** Otherwise, return a pointer to the first character not part of the rule.
546*/
547
548static const char *
549getrule(strp, rulep)
550const char *			strp;
551register struct rule * const	rulep;
552{
553	if (*strp == 'J') {
554		/*
555		** Julian day.
556		*/
557		rulep->r_type = JULIAN_DAY;
558		++strp;
559		strp = getnum(strp, &rulep->r_day, 1, DAYSPERNYEAR);
560	} else if (*strp == 'M') {
561		/*
562		** Month, week, day.
563		*/
564		rulep->r_type = MONTH_NTH_DAY_OF_WEEK;
565		++strp;
566		strp = getnum(strp, &rulep->r_mon, 1, MONSPERYEAR);
567		if (strp == NULL)
568			return NULL;
569		if (*strp++ != '.')
570			return NULL;
571		strp = getnum(strp, &rulep->r_week, 1, 5);
572		if (strp == NULL)
573			return NULL;
574		if (*strp++ != '.')
575			return NULL;
576		strp = getnum(strp, &rulep->r_day, 0, DAYSPERWEEK - 1);
577	} else if (is_digit(*strp)) {
578		/*
579		** Day of year.
580		*/
581		rulep->r_type = DAY_OF_YEAR;
582		strp = getnum(strp, &rulep->r_day, 0, DAYSPERLYEAR - 1);
583	} else	return NULL;		/* invalid format */
584	if (strp == NULL)
585		return NULL;
586	if (*strp == '/') {
587		/*
588		** Time specified.
589		*/
590		++strp;
591		strp = getsecs(strp, &rulep->r_time);
592	} else	rulep->r_time = 2 * SECSPERHOUR;	/* default = 2:00:00 */
593	return strp;
594}
595
596/*
597** Given the Epoch-relative time of January 1, 00:00:00 GMT, in a year, the
598** year, a rule, and the offset from GMT at the time that rule takes effect,
599** calculate the Epoch-relative time that rule takes effect.
600*/
601
602static time_t
603transtime(janfirst, year, rulep, offset)
604const time_t				janfirst;
605const int				year;
606register const struct rule * const	rulep;
607const long				offset;
608{
609	register int	leapyear;
610	register time_t	value;
611	register int	i;
612	int		d, m1, yy0, yy1, yy2, dow;
613
614	INITIALIZE(value);
615	leapyear = isleap(year);
616	switch (rulep->r_type) {
617
618	case JULIAN_DAY:
619		/*
620		** Jn - Julian day, 1 == January 1, 60 == March 1 even in leap
621		** years.
622		** In non-leap years, or if the day number is 59 or less, just
623		** add SECSPERDAY times the day number-1 to the time of
624		** January 1, midnight, to get the day.
625		*/
626		value = janfirst + (rulep->r_day - 1) * SECSPERDAY;
627		if (leapyear && rulep->r_day >= 60)
628			value += SECSPERDAY;
629		break;
630
631	case DAY_OF_YEAR:
632		/*
633		** n - day of year.
634		** Just add SECSPERDAY times the day number to the time of
635		** January 1, midnight, to get the day.
636		*/
637		value = janfirst + rulep->r_day * SECSPERDAY;
638		break;
639
640	case MONTH_NTH_DAY_OF_WEEK:
641		/*
642		** Mm.n.d - nth "dth day" of month m.
643		*/
644		value = janfirst;
645		for (i = 0; i < rulep->r_mon - 1; ++i)
646			value += mon_lengths[leapyear][i] * SECSPERDAY;
647
648		/*
649		** Use Zeller's Congruence to get day-of-week of first day of
650		** month.
651		*/
652		m1 = (rulep->r_mon + 9) % 12 + 1;
653		yy0 = (rulep->r_mon <= 2) ? (year - 1) : year;
654		yy1 = yy0 / 100;
655		yy2 = yy0 % 100;
656		dow = ((26 * m1 - 2) / 10 +
657			1 + yy2 + yy2 / 4 + yy1 / 4 - 2 * yy1) % 7;
658		if (dow < 0)
659			dow += DAYSPERWEEK;
660
661		/*
662		** "dow" is the day-of-week of the first day of the month.  Get
663		** the day-of-month (zero-origin) of the first "dow" day of the
664		** month.
665		*/
666		d = rulep->r_day - dow;
667		if (d < 0)
668			d += DAYSPERWEEK;
669		for (i = 1; i < rulep->r_week; ++i) {
670			if (d + DAYSPERWEEK >=
671				mon_lengths[leapyear][rulep->r_mon - 1])
672					break;
673			d += DAYSPERWEEK;
674		}
675
676		/*
677		** "d" is the day-of-month (zero-origin) of the day we want.
678		*/
679		value += d * SECSPERDAY;
680		break;
681	}
682
683	/*
684	** "value" is the Epoch-relative time of 00:00:00 GMT on the day in
685	** question.  To get the Epoch-relative time of the specified local
686	** time on that day, add the transition time and the current offset
687	** from GMT.
688	*/
689	return value + rulep->r_time + offset;
690}
691
692/*
693** Given a POSIX section 8-style TZ string, fill in the rule tables as
694** appropriate.
695*/
696
697static int
698tzparse(name, sp, lastditch)
699const char *			name;
700register struct state * const	sp;
701const int			lastditch;
702{
703	const char *			stdname;
704	const char *			dstname;
705	size_t				stdlen;
706	size_t				dstlen;
707	long				stdoffset;
708	long				dstoffset;
709	register time_t *		atp;
710	register unsigned char *	typep;
711	register char *			cp;
712	register int			load_result;
713
714	INITIALIZE(dstname);
715	stdname = name;
716	if (lastditch) {
717		stdlen = strlen(name);	/* length of standard zone name */
718		name += stdlen;
719		if (stdlen >= sizeof sp->chars)
720			stdlen = (sizeof sp->chars) - 1;
721	} else {
722		name = getzname(name);
723		stdlen = name - stdname;
724		if (stdlen < 3)
725			return -1;
726	}
727	if (*name == '\0')
728		return -1;	/* was "stdoffset = 0;" */
729	else {
730		name = getoffset(name, &stdoffset);
731		if (name == NULL)
732			return -1;
733	}
734	load_result = tzload(TZDEFRULES, sp);
735	if (load_result != 0)
736		sp->leapcnt = 0;		/* so, we're off a little */
737	if (*name != '\0') {
738		dstname = name;
739		name = getzname(name);
740		dstlen = name - dstname;	/* length of DST zone name */
741		if (dstlen < 3)
742			return -1;
743		if (*name != '\0' && *name != ',' && *name != ';') {
744			name = getoffset(name, &dstoffset);
745			if (name == NULL)
746				return -1;
747		} else	dstoffset = stdoffset - SECSPERHOUR;
748		if (*name == ',' || *name == ';') {
749			struct rule	start;
750			struct rule	end;
751			register int	year;
752			register time_t	janfirst;
753			time_t		starttime;
754			time_t		endtime;
755
756			++name;
757			if ((name = getrule(name, &start)) == NULL)
758				return -1;
759			if (*name++ != ',')
760				return -1;
761			if ((name = getrule(name, &end)) == NULL)
762				return -1;
763			if (*name != '\0')
764				return -1;
765			sp->typecnt = 2;	/* standard time and DST */
766			/*
767			** Two transitions per year, from EPOCH_YEAR to 2037.
768			*/
769			sp->timecnt = 2 * (2037 - EPOCH_YEAR + 1);
770			if (sp->timecnt > TZ_MAX_TIMES)
771				return -1;
772			sp->ttis[0].tt_gmtoff = -dstoffset;
773			sp->ttis[0].tt_isdst = 1;
774			sp->ttis[0].tt_abbrind = stdlen + 1;
775			sp->ttis[1].tt_gmtoff = -stdoffset;
776			sp->ttis[1].tt_isdst = 0;
777			sp->ttis[1].tt_abbrind = 0;
778			atp = sp->ats;
779			typep = sp->types;
780			janfirst = 0;
781			for (year = EPOCH_YEAR; year <= 2037; ++year) {
782				starttime = transtime(janfirst, year, &start,
783					stdoffset);
784				endtime = transtime(janfirst, year, &end,
785					dstoffset);
786				if (starttime > endtime) {
787					*atp++ = endtime;
788					*typep++ = 1;	/* DST ends */
789					*atp++ = starttime;
790					*typep++ = 0;	/* DST begins */
791				} else {
792					*atp++ = starttime;
793					*typep++ = 0;	/* DST begins */
794					*atp++ = endtime;
795					*typep++ = 1;	/* DST ends */
796				}
797				janfirst += year_lengths[isleap(year)] *
798					SECSPERDAY;
799			}
800		} else {
801			register long	theirstdoffset;
802			register long	theirdstoffset;
803			register long	theiroffset;
804			register int	isdst;
805			register int	i;
806			register int	j;
807
808			if (*name != '\0')
809				return -1;
810			if (load_result != 0)
811				return -1;
812			/*
813			** Initial values of theirstdoffset and theirdstoffset.
814			*/
815			theirstdoffset = 0;
816			for (i = 0; i < sp->timecnt; ++i) {
817				j = sp->types[i];
818				if (!sp->ttis[j].tt_isdst) {
819					theirstdoffset =
820						-sp->ttis[j].tt_gmtoff;
821					break;
822				}
823			}
824			theirdstoffset = 0;
825			for (i = 0; i < sp->timecnt; ++i) {
826				j = sp->types[i];
827				if (sp->ttis[j].tt_isdst) {
828					theirdstoffset =
829						-sp->ttis[j].tt_gmtoff;
830					break;
831				}
832			}
833			/*
834			** Initially we're assumed to be in standard time.
835			*/
836			isdst = FALSE;
837			theiroffset = theirstdoffset;
838			/*
839			** Now juggle transition times and types
840			** tracking offsets as you do.
841			*/
842			for (i = 0; i < sp->timecnt; ++i) {
843				j = sp->types[i];
844				sp->types[i] = sp->ttis[j].tt_isdst;
845				if (sp->ttis[j].tt_ttisgmt) {
846					/* No adjustment to transition time */
847				} else {
848					/*
849					** If summer time is in effect, and the
850					** transition time was not specified as
851					** standard time, add the summer time
852					** offset to the transition time;
853					** otherwise, add the standard time
854					** offset to the transition time.
855					*/
856					/*
857					** Transitions from DST to DDST
858					** will effectively disappear since
859					** POSIX provides for only one DST
860					** offset.
861					*/
862					if (isdst && !sp->ttis[j].tt_ttisstd) {
863						sp->ats[i] += dstoffset -
864							theirdstoffset;
865					} else {
866						sp->ats[i] += stdoffset -
867							theirstdoffset;
868					}
869				}
870				theiroffset = -sp->ttis[j].tt_gmtoff;
871				if (sp->ttis[j].tt_isdst)
872					theirdstoffset = theiroffset;
873				else	theirstdoffset = theiroffset;
874			}
875			/*
876			** Finally, fill in ttis.
877			** ttisstd and ttisgmt need not be handled.
878			*/
879			sp->ttis[0].tt_gmtoff = -stdoffset;
880			sp->ttis[0].tt_isdst = FALSE;
881			sp->ttis[0].tt_abbrind = 0;
882			sp->ttis[1].tt_gmtoff = -dstoffset;
883			sp->ttis[1].tt_isdst = TRUE;
884			sp->ttis[1].tt_abbrind = stdlen + 1;
885		}
886	} else {
887		dstlen = 0;
888		sp->typecnt = 1;		/* only standard time */
889		sp->timecnt = 0;
890		sp->ttis[0].tt_gmtoff = -stdoffset;
891		sp->ttis[0].tt_isdst = 0;
892		sp->ttis[0].tt_abbrind = 0;
893	}
894	sp->charcnt = stdlen + 1;
895	if (dstlen != 0)
896		sp->charcnt += dstlen + 1;
897	if (sp->charcnt > sizeof sp->chars)
898		return -1;
899	cp = sp->chars;
900	(void) strncpy(cp, stdname, stdlen);
901	cp += stdlen;
902	*cp++ = '\0';
903	if (dstlen != 0) {
904		(void) strncpy(cp, dstname, dstlen);
905		*(cp + dstlen) = '\0';
906	}
907	return 0;
908}
909
910static void
911gmtload(sp)
912struct state * const	sp;
913{
914	if (tzload(gmt, sp) != 0)
915		(void) tzparse(gmt, sp, TRUE);
916}
917
918#ifndef STD_INSPIRED
919/*
920** A non-static declaration of tzsetwall in a system header file
921** may cause a warning about this upcoming static declaration...
922*/
923static
924#endif /* !defined STD_INSPIRED */
925#ifdef	_THREAD_SAFE
926void
927tzsetwall_basic P((void))
928#else
929void
930tzsetwall P((void))
931#endif
932{
933	if (lcl_is_set < 0)
934		return;
935	lcl_is_set = -1;
936
937#ifdef ALL_STATE
938	if (lclptr == NULL) {
939		lclptr = (struct state *) malloc(sizeof *lclptr);
940		if (lclptr == NULL) {
941			settzname();	/* all we can do */
942			return;
943		}
944	}
945#endif /* defined ALL_STATE */
946	if (tzload((char *) NULL, lclptr) != 0)
947		gmtload(lclptr);
948	settzname();
949}
950
951#ifdef	_THREAD_SAFE
952void
953tzsetwall P((void))
954{
955	pthread_mutex_lock(&lcl_mutex);
956	tzsetwall_basic();
957	pthread_mutex_unlock(&lcl_mutex);
958}
959#endif
960
961#ifdef	_THREAD_SAFE
962static void
963tzset_basic P((void))
964#else
965void
966tzset P((void))
967#endif
968{
969	register const char *	name;
970
971	name = getenv("TZ");
972	if (name == NULL) {
973		tzsetwall();
974		return;
975	}
976
977	if (lcl_is_set > 0  &&  strcmp(lcl_TZname, name) == 0)
978		return;
979	lcl_is_set = (strlen(name) < sizeof(lcl_TZname));
980	if (lcl_is_set)
981		(void) strcpy(lcl_TZname, name);
982
983#ifdef ALL_STATE
984	if (lclptr == NULL) {
985		lclptr = (struct state *) malloc(sizeof *lclptr);
986		if (lclptr == NULL) {
987			settzname();	/* all we can do */
988			return;
989		}
990	}
991#endif /* defined ALL_STATE */
992	if (*name == '\0') {
993		/*
994		** User wants it fast rather than right.
995		*/
996		lclptr->leapcnt = 0;		/* so, we're off a little */
997		lclptr->timecnt = 0;
998		lclptr->ttis[0].tt_gmtoff = 0;
999		lclptr->ttis[0].tt_abbrind = 0;
1000		(void) strcpy(lclptr->chars, gmt);
1001	} else if (tzload(name, lclptr) != 0)
1002		if (name[0] == ':' || tzparse(name, lclptr, FALSE) != 0)
1003			(void) gmtload(lclptr);
1004	settzname();
1005}
1006
1007#ifdef	_THREAD_SAFE
1008void
1009tzset P((void))
1010{
1011	pthread_mutex_lock(&lcl_mutex);
1012	tzset_basic();
1013	pthread_mutex_unlock(&lcl_mutex);
1014}
1015#endif
1016
1017/*
1018** The easy way to behave "as if no library function calls" localtime
1019** is to not call it--so we drop its guts into "localsub", which can be
1020** freely called.  (And no, the PANS doesn't require the above behavior--
1021** but it *is* desirable.)
1022**
1023** The unused offset argument is for the benefit of mktime variants.
1024*/
1025
1026/*ARGSUSED*/
1027static void
1028localsub(timep, offset, tmp)
1029const time_t * const	timep;
1030const long		offset;
1031struct tm * const	tmp;
1032{
1033	register struct state *		sp;
1034	register const struct ttinfo *	ttisp;
1035	register int			i;
1036	const time_t			t = *timep;
1037
1038	sp = lclptr;
1039#ifdef ALL_STATE
1040	if (sp == NULL) {
1041		gmtsub(timep, offset, tmp);
1042		return;
1043	}
1044#endif /* defined ALL_STATE */
1045	if (sp->timecnt == 0 || t < sp->ats[0]) {
1046		i = 0;
1047		while (sp->ttis[i].tt_isdst)
1048			if (++i >= sp->typecnt) {
1049				i = 0;
1050				break;
1051			}
1052	} else {
1053		for (i = 1; i < sp->timecnt; ++i)
1054			if (t < sp->ats[i])
1055				break;
1056		i = sp->types[i - 1];
1057	}
1058	ttisp = &sp->ttis[i];
1059	/*
1060	** To get (wrong) behavior that's compatible with System V Release 2.0
1061	** you'd replace the statement below with
1062	**	t += ttisp->tt_gmtoff;
1063	**	timesub(&t, 0L, sp, tmp);
1064	*/
1065	timesub(&t, ttisp->tt_gmtoff, sp, tmp);
1066	tmp->tm_isdst = ttisp->tt_isdst;
1067	tzname[tmp->tm_isdst] = &sp->chars[ttisp->tt_abbrind];
1068#ifdef TM_ZONE
1069	tmp->TM_ZONE = &sp->chars[ttisp->tt_abbrind];
1070#endif /* defined TM_ZONE */
1071}
1072
1073#ifdef	_THREAD_SAFE
1074int
1075localtime_r(timep, p_tm)
1076const time_t * const	timep;
1077struct tm *p_tm;
1078{
1079	pthread_mutex_lock(&lcl_mutex);
1080	tzset();
1081	localsub(timep, 0L, p_tm);
1082	pthread_mutex_unlock(&lcl_mutex);
1083	return(0);
1084}
1085#endif
1086
1087struct tm *
1088localtime(timep)
1089const time_t * const	timep;
1090{
1091#ifdef	_THREAD_SAFE
1092	static struct pthread_mutex _localtime_mutex = PTHREAD_MUTEX_INITIALIZER;
1093	static pthread_mutex_t localtime_mutex = &_localtime_mutex;
1094	static pthread_key_t localtime_key = -1;
1095	struct tm *p_tm;
1096
1097	pthread_mutex_lock(&localtime_mutex);
1098	if (localtime_key < 0) {
1099		if (pthread_keycreate(&localtime_key, free) < 0) {
1100			pthread_mutex_unlock(&localtime_mutex);
1101			return(NULL);
1102		}
1103	}
1104	pthread_mutex_unlock(&localtime_mutex);
1105	if (pthread_getspecific(localtime_key,(void **) &p_tm) != 0) {
1106		return(NULL);
1107	} else if (p_tm == NULL) {
1108		if ((p_tm = (struct tm *)malloc(sizeof(struct tm))) == NULL) {
1109			return(NULL);
1110		}
1111		pthread_setspecific(localtime_key, p_tm);
1112	}
1113	pthread_mutex_lock(&lcl_mutex);
1114	tzset();
1115	localsub(timep, 0L, p_tm);
1116	pthread_mutex_unlock(&lcl_mutex);
1117	return p_tm;
1118#else
1119	tzset();
1120	localsub(timep, 0L, &tm);
1121	return &tm;
1122#endif
1123}
1124
1125/*
1126** gmtsub is to gmtime as localsub is to localtime.
1127*/
1128
1129static void
1130gmtsub(timep, offset, tmp)
1131const time_t * const	timep;
1132const long		offset;
1133struct tm * const	tmp;
1134{
1135#ifdef	_THREAD_SAFE
1136	pthread_mutex_lock(&gmt_mutex);
1137#endif
1138	if (!gmt_is_set) {
1139		gmt_is_set = TRUE;
1140#ifdef ALL_STATE
1141		gmtptr = (struct state *) malloc(sizeof *gmtptr);
1142		if (gmtptr != NULL)
1143#endif /* defined ALL_STATE */
1144			gmtload(gmtptr);
1145	}
1146#ifdef	_THREAD_SAFE
1147	pthread_mutex_unlock(&gmt_mutex);
1148#endif
1149	timesub(timep, offset, gmtptr, tmp);
1150#ifdef TM_ZONE
1151	/*
1152	** Could get fancy here and deliver something such as
1153	** "GMT+xxxx" or "GMT-xxxx" if offset is non-zero,
1154	** but this is no time for a treasure hunt.
1155	*/
1156	if (offset != 0)
1157		tmp->TM_ZONE = wildabbr;
1158	else {
1159#ifdef ALL_STATE
1160		if (gmtptr == NULL)
1161			tmp->TM_ZONE = gmt;
1162		else	tmp->TM_ZONE = gmtptr->chars;
1163#endif /* defined ALL_STATE */
1164#ifndef ALL_STATE
1165		tmp->TM_ZONE = gmtptr->chars;
1166#endif /* State Farm */
1167	}
1168#endif /* defined TM_ZONE */
1169}
1170
1171struct tm *
1172gmtime(timep)
1173const time_t * const	timep;
1174{
1175#ifdef	_THREAD_SAFE
1176	static struct pthread_mutex _gmtime_mutex = PTHREAD_MUTEX_INITIALIZER;
1177	static pthread_mutex_t gmtime_mutex = &_gmtime_mutex;
1178	static pthread_key_t gmtime_key = -1;
1179	struct tm *p_tm;
1180
1181	pthread_mutex_lock(&gmtime_mutex);
1182	if (gmtime_key < 0) {
1183		if (pthread_keycreate(&gmtime_key, free) < 0) {
1184			pthread_mutex_unlock(&gmtime_mutex);
1185			return(NULL);
1186		}
1187	}
1188	pthread_mutex_unlock(&gmtime_mutex);
1189	if (pthread_getspecific(gmtime_key,(void **) &p_tm) != 0) {
1190		return(NULL);
1191	} else if (p_tm == NULL) {
1192		if ((p_tm = (struct tm *)malloc(sizeof(struct tm))) == NULL) {
1193			return(NULL);
1194		}
1195		pthread_setspecific(gmtime_key, p_tm);
1196	}
1197	gmtsub(timep, 0L, p_tm);
1198	return(p_tm);
1199#else
1200	gmtsub(timep, 0L, &tm);
1201	return &tm;
1202#endif
1203}
1204
1205#ifdef	_THREAD_SAFE
1206int
1207gmtime_r(const time_t * timep, struct tm * tm)
1208{
1209	gmtsub(timep, 0L, tm);
1210	return(0);
1211}
1212#endif
1213
1214#ifdef STD_INSPIRED
1215
1216struct tm *
1217offtime(timep, offset)
1218const time_t * const	timep;
1219const long		offset;
1220{
1221	gmtsub(timep, offset, &tm);
1222	return &tm;
1223}
1224
1225#endif /* defined STD_INSPIRED */
1226
1227static void
1228timesub(timep, offset, sp, tmp)
1229const time_t * const			timep;
1230const long				offset;
1231register const struct state * const	sp;
1232register struct tm * const		tmp;
1233{
1234	register const struct lsinfo *	lp;
1235	register long			days;
1236	register long			rem;
1237	register int			y;
1238	register int			yleap;
1239	register const int *		ip;
1240	register long			corr;
1241	register int			hit;
1242	register int			i;
1243
1244	corr = 0;
1245	hit = 0;
1246#ifdef ALL_STATE
1247	i = (sp == NULL) ? 0 : sp->leapcnt;
1248#endif /* defined ALL_STATE */
1249#ifndef ALL_STATE
1250	i = sp->leapcnt;
1251#endif /* State Farm */
1252	while (--i >= 0) {
1253		lp = &sp->lsis[i];
1254		if (*timep >= lp->ls_trans) {
1255			if (*timep == lp->ls_trans) {
1256				hit = ((i == 0 && lp->ls_corr > 0) ||
1257					lp->ls_corr > sp->lsis[i - 1].ls_corr);
1258				if (hit)
1259					while (i > 0 &&
1260						sp->lsis[i].ls_trans ==
1261						sp->lsis[i - 1].ls_trans + 1 &&
1262						sp->lsis[i].ls_corr ==
1263						sp->lsis[i - 1].ls_corr + 1) {
1264							++hit;
1265							--i;
1266					}
1267			}
1268			corr = lp->ls_corr;
1269			break;
1270		}
1271	}
1272	days = *timep / SECSPERDAY;
1273	rem = *timep % SECSPERDAY;
1274#ifdef mc68k
1275	if (*timep == 0x80000000) {
1276		/*
1277		** A 3B1 muffs the division on the most negative number.
1278		*/
1279		days = -24855;
1280		rem = -11648;
1281	}
1282#endif /* defined mc68k */
1283	rem += (offset - corr);
1284	while (rem < 0) {
1285		rem += SECSPERDAY;
1286		--days;
1287	}
1288	while (rem >= SECSPERDAY) {
1289		rem -= SECSPERDAY;
1290		++days;
1291	}
1292	tmp->tm_hour = (int) (rem / SECSPERHOUR);
1293	rem = rem % SECSPERHOUR;
1294	tmp->tm_min = (int) (rem / SECSPERMIN);
1295	/*
1296	** A positive leap second requires a special
1297	** representation.  This uses "... ??:59:60" et seq.
1298	*/
1299	tmp->tm_sec = (int) (rem % SECSPERMIN) + hit;
1300	tmp->tm_wday = (int) ((EPOCH_WDAY + days) % DAYSPERWEEK);
1301	if (tmp->tm_wday < 0)
1302		tmp->tm_wday += DAYSPERWEEK;
1303	y = EPOCH_YEAR;
1304#define LEAPS_THRU_END_OF(y)	((y) / 4 - (y) / 100 + (y) / 400)
1305	while (days < 0 || days >= (long) year_lengths[yleap = isleap(y)]) {
1306		register int	newy;
1307
1308		newy = y + days / DAYSPERNYEAR;
1309		if (days < 0)
1310			--newy;
1311		days -= (newy - y) * DAYSPERNYEAR +
1312			LEAPS_THRU_END_OF(newy - 1) -
1313			LEAPS_THRU_END_OF(y - 1);
1314		y = newy;
1315	}
1316	tmp->tm_year = y - TM_YEAR_BASE;
1317	tmp->tm_yday = (int) days;
1318	ip = mon_lengths[yleap];
1319	for (tmp->tm_mon = 0; days >= (long) ip[tmp->tm_mon]; ++(tmp->tm_mon))
1320		days = days - (long) ip[tmp->tm_mon];
1321	tmp->tm_mday = (int) (days + 1);
1322	tmp->tm_isdst = 0;
1323#ifdef TM_GMTOFF
1324	tmp->TM_GMTOFF = offset;
1325#endif /* defined TM_GMTOFF */
1326}
1327
1328char *
1329ctime(timep)
1330const time_t * const	timep;
1331{
1332/*
1333** Section 4.12.3.2 of X3.159-1989 requires that
1334**	The ctime funciton converts the calendar time pointed to by timer
1335**	to local time in the form of a string.  It is equivalent to
1336**		asctime(localtime(timer))
1337*/
1338	return asctime(localtime(timep));
1339}
1340
1341/*
1342** Adapted from code provided by Robert Elz, who writes:
1343**	The "best" way to do mktime I think is based on an idea of Bob
1344**	Kridle's (so its said...) from a long time ago.
1345**	[kridle@xinet.com as of 1996-01-16.]
1346**	It does a binary search of the time_t space.  Since time_t's are
1347**	just 32 bits, its a max of 32 iterations (even at 64 bits it
1348**	would still be very reasonable).
1349*/
1350
1351#ifndef WRONG
1352#define WRONG	(-1)
1353#endif /* !defined WRONG */
1354
1355/*
1356** Simplified normalize logic courtesy Paul Eggert (eggert@twinsun.com).
1357*/
1358
1359static int
1360increment_overflow(number, delta)
1361int *	number;
1362int	delta;
1363{
1364	int	number0;
1365
1366	number0 = *number;
1367	*number += delta;
1368	return (*number < number0) != (delta < 0);
1369}
1370
1371static int
1372normalize_overflow(tensptr, unitsptr, base)
1373int * const	tensptr;
1374int * const	unitsptr;
1375const int	base;
1376{
1377	register int	tensdelta;
1378
1379	tensdelta = (*unitsptr >= 0) ?
1380		(*unitsptr / base) :
1381		(-1 - (-1 - *unitsptr) / base);
1382	*unitsptr -= tensdelta * base;
1383	return increment_overflow(tensptr, tensdelta);
1384}
1385
1386static int
1387tmcomp(atmp, btmp)
1388register const struct tm * const atmp;
1389register const struct tm * const btmp;
1390{
1391	register int	result;
1392
1393	if ((result = (atmp->tm_year - btmp->tm_year)) == 0 &&
1394		(result = (atmp->tm_mon - btmp->tm_mon)) == 0 &&
1395		(result = (atmp->tm_mday - btmp->tm_mday)) == 0 &&
1396		(result = (atmp->tm_hour - btmp->tm_hour)) == 0 &&
1397		(result = (atmp->tm_min - btmp->tm_min)) == 0)
1398			result = atmp->tm_sec - btmp->tm_sec;
1399	return result;
1400}
1401
1402static time_t
1403time2(tmp, funcp, offset, okayp)
1404struct tm * const	tmp;
1405void (* const		funcp) P((const time_t*, long, struct tm*));
1406const long		offset;
1407int * const		okayp;
1408{
1409	register const struct state *	sp;
1410	register int			dir;
1411	register int			bits;
1412	register int			i, j ;
1413	register int			saved_seconds;
1414	time_t				newt;
1415	time_t				t;
1416	struct tm			yourtm, mytm;
1417
1418	*okayp = FALSE;
1419	yourtm = *tmp;
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	t = TYPE_SIGNED(time_t) ? 0 : (((time_t) 1) << bits);
1485	for ( ; ; ) {
1486		(*funcp)(&t, offset, &mytm);
1487		dir = tmcomp(&mytm, &yourtm);
1488		if (dir != 0) {
1489			if (bits-- < 0)
1490				return WRONG;
1491			if (bits < 0)
1492				--t; /* may be needed if new t is minimal */
1493			else if (dir > 0)
1494				t -= ((time_t) 1) << bits;
1495			else	t += ((time_t) 1) << bits;
1496			continue;
1497		}
1498		if (yourtm.tm_isdst < 0 || mytm.tm_isdst == yourtm.tm_isdst)
1499			break;
1500		/*
1501		** Right time, wrong type.
1502		** Hunt for right time, right type.
1503		** It's okay to guess wrong since the guess
1504		** gets checked.
1505		*/
1506		/*
1507		** The (void *) casts are the benefit of SunOS 3.3 on Sun 2's.
1508		*/
1509		sp = (const struct state *)
1510			(((void *) funcp == (void *) localsub) ?
1511			lclptr : gmtptr);
1512#ifdef ALL_STATE
1513		if (sp == NULL)
1514			return WRONG;
1515#endif /* defined ALL_STATE */
1516		for (i = sp->typecnt - 1; i >= 0; --i) {
1517			if (sp->ttis[i].tt_isdst != yourtm.tm_isdst)
1518				continue;
1519			for (j = sp->typecnt - 1; j >= 0; --j) {
1520				if (sp->ttis[j].tt_isdst == yourtm.tm_isdst)
1521					continue;
1522				newt = t + sp->ttis[j].tt_gmtoff -
1523					sp->ttis[i].tt_gmtoff;
1524				(*funcp)(&newt, offset, &mytm);
1525				if (tmcomp(&mytm, &yourtm) != 0)
1526					continue;
1527				if (mytm.tm_isdst != yourtm.tm_isdst)
1528					continue;
1529				/*
1530				** We have a match.
1531				*/
1532				t = newt;
1533				goto label;
1534			}
1535		}
1536		return WRONG;
1537	}
1538label:
1539	newt = t + saved_seconds;
1540	if ((newt < t) != (saved_seconds < 0))
1541		return WRONG;
1542	t = newt;
1543	(*funcp)(&t, offset, tmp);
1544	*okayp = TRUE;
1545	return t;
1546}
1547
1548static time_t
1549time1(tmp, funcp, offset)
1550struct tm * const	tmp;
1551void (* const		funcp) P((const time_t *, long, struct tm *));
1552const long		offset;
1553{
1554	register time_t			t;
1555	register const struct state *	sp;
1556	register int			samei, otheri;
1557	int				okay;
1558
1559	if (tmp->tm_isdst > 1)
1560		tmp->tm_isdst = 1;
1561	t = time2(tmp, funcp, offset, &okay);
1562#ifdef PCTS
1563	/*
1564	** PCTS code courtesy Grant Sullivan (grant@osf.org).
1565	*/
1566	if (okay)
1567		return t;
1568	if (tmp->tm_isdst < 0)
1569		tmp->tm_isdst = 0;	/* reset to std and try again */
1570#endif /* defined PCTS */
1571#ifndef PCTS
1572	if (okay || tmp->tm_isdst < 0)
1573		return t;
1574#endif /* !defined PCTS */
1575	/*
1576	** We're supposed to assume that somebody took a time of one type
1577	** and did some math on it that yielded a "struct tm" that's bad.
1578	** We try to divine the type they started from and adjust to the
1579	** type they need.
1580	*/
1581	/*
1582	** The (void *) casts are the benefit of SunOS 3.3 on Sun 2's.
1583	*/
1584	sp = (const struct state *) (((void *) funcp == (void *) localsub) ?
1585		lclptr : gmtptr);
1586#ifdef ALL_STATE
1587	if (sp == NULL)
1588		return WRONG;
1589#endif /* defined ALL_STATE */
1590	for (samei = sp->typecnt - 1; samei >= 0; --samei) {
1591		if (sp->ttis[samei].tt_isdst != tmp->tm_isdst)
1592			continue;
1593		for (otheri = sp->typecnt - 1; otheri >= 0; --otheri) {
1594			if (sp->ttis[otheri].tt_isdst == tmp->tm_isdst)
1595				continue;
1596			tmp->tm_sec += sp->ttis[otheri].tt_gmtoff -
1597					sp->ttis[samei].tt_gmtoff;
1598			tmp->tm_isdst = !tmp->tm_isdst;
1599			t = time2(tmp, funcp, offset, &okay);
1600			if (okay)
1601				return t;
1602			tmp->tm_sec -= sp->ttis[otheri].tt_gmtoff -
1603					sp->ttis[samei].tt_gmtoff;
1604			tmp->tm_isdst = !tmp->tm_isdst;
1605		}
1606	}
1607	return WRONG;
1608}
1609
1610time_t
1611mktime(tmp)
1612struct tm * const	tmp;
1613{
1614	time_t mktime_return_value;
1615#ifdef	_THREAD_SAFE
1616	pthread_mutex_lock(&lcl_mutex);
1617#endif
1618	tzset();
1619	mktime_return_value = time1(tmp, localsub, 0L);
1620#ifdef	_THREAD_SAFE
1621	pthread_mutex_unlock(&lcl_mutex);
1622#endif
1623	return(mktime_return_value);
1624}
1625
1626#ifdef STD_INSPIRED
1627
1628time_t
1629timelocal(tmp)
1630struct tm * const	tmp;
1631{
1632	tmp->tm_isdst = -1;	/* in case it wasn't initialized */
1633	return mktime(tmp);
1634}
1635
1636time_t
1637timegm(tmp)
1638struct tm * const	tmp;
1639{
1640	tmp->tm_isdst = 0;
1641	return time1(tmp, gmtsub, 0L);
1642}
1643
1644time_t
1645timeoff(tmp, offset)
1646struct tm * const	tmp;
1647const long		offset;
1648{
1649	tmp->tm_isdst = 0;
1650	return time1(tmp, gmtsub, offset);
1651}
1652
1653#endif /* defined STD_INSPIRED */
1654
1655#ifdef CMUCS
1656
1657/*
1658** The following is supplied for compatibility with
1659** previous versions of the CMUCS runtime library.
1660*/
1661
1662long
1663gtime(tmp)
1664struct tm * const	tmp;
1665{
1666	const time_t	t = mktime(tmp);
1667
1668	if (t == WRONG)
1669		return -1;
1670	return t;
1671}
1672
1673#endif /* defined CMUCS */
1674
1675/*
1676** XXX--is the below the right way to conditionalize??
1677*/
1678
1679#ifdef STD_INSPIRED
1680
1681/*
1682** IEEE Std 1003.1-1988 (POSIX) legislates that 536457599
1683** shall correspond to "Wed Dec 31 23:59:59 GMT 1986", which
1684** is not the case if we are accounting for leap seconds.
1685** So, we provide the following conversion routines for use
1686** when exchanging timestamps with POSIX conforming systems.
1687*/
1688
1689static long
1690leapcorr(timep)
1691time_t *	timep;
1692{
1693	register struct state *		sp;
1694	register struct lsinfo *	lp;
1695	register int			i;
1696
1697	sp = lclptr;
1698	i = sp->leapcnt;
1699	while (--i >= 0) {
1700		lp = &sp->lsis[i];
1701		if (*timep >= lp->ls_trans)
1702			return lp->ls_corr;
1703	}
1704	return 0;
1705}
1706
1707time_t
1708time2posix(t)
1709time_t	t;
1710{
1711	tzset();
1712	return t - leapcorr(&t);
1713}
1714
1715time_t
1716posix2time(t)
1717time_t	t;
1718{
1719	time_t	x;
1720	time_t	y;
1721
1722	tzset();
1723	/*
1724	** For a positive leap second hit, the result
1725	** is not unique.  For a negative leap second
1726	** hit, the corresponding time doesn't exist,
1727	** so we return an adjacent second.
1728	*/
1729	x = t + leapcorr(&t);
1730	y = x - leapcorr(&x);
1731	if (y < t) {
1732		do {
1733			x++;
1734			y = x - leapcorr(&x);
1735		} while (y < t);
1736		if (t != y)
1737			return x - 1;
1738	} else if (y > t) {
1739		do {
1740			--x;
1741			y = x - leapcorr(&x);
1742		} while (y > t);
1743		if (t != y)
1744			return x + 1;
1745	}
1746	return x;
1747}
1748
1749#endif /* defined STD_INSPIRED */
1750