xref: /openbsd/lib/libc/time/localtime.c (revision a6445c1d)
1 /*	$OpenBSD: localtime.c,v 1.38 2013/04/17 17:40:35 tedu Exp $ */
2 /*
3 ** This file is in the public domain, so clarified as of
4 ** 1996-06-05 by Arthur David Olson.
5 */
6 
7 /*
8 ** Leap second handling from Bradley White.
9 ** POSIX-style TZ environment variable handling from Guy Harris.
10 */
11 
12 /*LINTLIBRARY*/
13 
14 #include "private.h"
15 #include "tzfile.h"
16 #include "fcntl.h"
17 #include "float.h"	/* for FLT_MAX and DBL_MAX */
18 #include "thread_private.h"
19 
20 #ifndef TZ_ABBR_MAX_LEN
21 #define TZ_ABBR_MAX_LEN	16
22 #endif /* !defined TZ_ABBR_MAX_LEN */
23 
24 #ifndef TZ_ABBR_CHAR_SET
25 #define TZ_ABBR_CHAR_SET \
26 	"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789 :+-._"
27 #endif /* !defined TZ_ABBR_CHAR_SET */
28 
29 #ifndef TZ_ABBR_ERR_CHAR
30 #define TZ_ABBR_ERR_CHAR	'_'
31 #endif /* !defined TZ_ABBR_ERR_CHAR */
32 
33 /*
34 ** SunOS 4.1.1 headers lack O_BINARY.
35 */
36 
37 #ifdef O_BINARY
38 #define OPEN_MODE	(O_RDONLY | O_BINARY)
39 #endif /* defined O_BINARY */
40 #ifndef O_BINARY
41 #define OPEN_MODE	O_RDONLY
42 #endif /* !defined O_BINARY */
43 
44 #ifndef WILDABBR
45 /*
46 ** Someone might make incorrect use of a time zone abbreviation:
47 **	1.	They might reference tzname[0] before calling tzset (explicitly
48 **		or implicitly).
49 **	2.	They might reference tzname[1] before calling tzset (explicitly
50 **		or implicitly).
51 **	3.	They might reference tzname[1] after setting to a time zone
52 **		in which Daylight Saving Time is never observed.
53 **	4.	They might reference tzname[0] after setting to a time zone
54 **		in which Standard Time is never observed.
55 **	5.	They might reference tm.TM_ZONE after calling offtime.
56 ** What's best to do in the above cases is open to debate;
57 ** for now, we just set things up so that in any of the five cases
58 ** WILDABBR is used. Another possibility: initialize tzname[0] to the
59 ** string "tzname[0] used before set", and similarly for the other cases.
60 ** And another: initialize tzname[0] to "ERA", with an explanation in the
61 ** manual page of what this "time zone abbreviation" means (doing this so
62 ** that tzname[0] has the "normal" length of three characters).
63 */
64 #define WILDABBR	"   "
65 #endif /* !defined WILDABBR */
66 
67 static char		wildabbr[] = WILDABBR;
68 
69 static const char	gmt[] = "GMT";
70 
71 /*
72 ** The DST rules to use if TZ has no rules and we can't load TZDEFRULES.
73 ** We default to US rules as of 1999-08-17.
74 ** POSIX 1003.1 section 8.1.1 says that the default DST rules are
75 ** implementation dependent; for historical reasons, US rules are a
76 ** common default.
77 */
78 #ifndef TZDEFRULESTRING
79 #define TZDEFRULESTRING ",M4.1.0,M10.5.0"
80 #endif /* !defined TZDEFDST */
81 
82 struct ttinfo {				/* time type information */
83 	long		tt_gmtoff;	/* UTC offset in seconds */
84 	int		tt_isdst;	/* used to set tm_isdst */
85 	int		tt_abbrind;	/* abbreviation list index */
86 	int		tt_ttisstd;	/* TRUE if transition is std time */
87 	int		tt_ttisgmt;	/* TRUE if transition is UTC */
88 };
89 
90 struct lsinfo {				/* leap second information */
91 	time_t		ls_trans;	/* transition time */
92 	long		ls_corr;	/* correction to apply */
93 };
94 
95 #define BIGGEST(a, b)	(((a) > (b)) ? (a) : (b))
96 
97 #ifdef TZNAME_MAX
98 #define MY_TZNAME_MAX	TZNAME_MAX
99 #endif /* defined TZNAME_MAX */
100 #ifndef TZNAME_MAX
101 #define MY_TZNAME_MAX	255
102 #endif /* !defined TZNAME_MAX */
103 
104 struct state {
105 	int		leapcnt;
106 	int		timecnt;
107 	int		typecnt;
108 	int		charcnt;
109 	int		goback;
110 	int		goahead;
111 	time_t		ats[TZ_MAX_TIMES];
112 	unsigned char	types[TZ_MAX_TIMES];
113 	struct ttinfo	ttis[TZ_MAX_TYPES];
114 	char		chars[BIGGEST(BIGGEST(TZ_MAX_CHARS + 1, sizeof gmt),
115 				(2 * (MY_TZNAME_MAX + 1)))];
116 	struct lsinfo	lsis[TZ_MAX_LEAPS];
117 };
118 
119 struct rule {
120 	int		r_type;		/* type of rule--see below */
121 	int		r_day;		/* day number of rule */
122 	int		r_week;		/* week number of rule */
123 	int		r_mon;		/* month number of rule */
124 	long		r_time;		/* transition time of rule */
125 };
126 
127 #define JULIAN_DAY		0	/* Jn - Julian day */
128 #define DAY_OF_YEAR		1	/* n - day of year */
129 #define MONTH_NTH_DAY_OF_WEEK	2	/* Mm.n.d - month, week, day of week */
130 
131 /*
132 ** Prototypes for static functions.
133 */
134 
135 static long		detzcode(const char * codep);
136 static time_t		detzcode64(const char * codep);
137 static int		differ_by_repeat(time_t t1, time_t t0);
138 static const char *	getzname(const char * strp);
139 static const char *	getqzname(const char * strp, const int delim);
140 static const char *	getnum(const char * strp, int * nump, int min,
141 				int max);
142 static const char *	getsecs(const char * strp, long * secsp);
143 static const char *	getoffset(const char * strp, long * offsetp);
144 static const char *	getrule(const char * strp, struct rule * rulep);
145 static void		gmtload(struct state * sp);
146 static struct tm *	gmtsub(const time_t * timep, long offset,
147 				struct tm * tmp);
148 static struct tm *	localsub(const time_t * timep, long offset,
149 				struct tm * tmp);
150 static int		increment_overflow(int * number, int delta);
151 static int		leaps_thru_end_of(int y);
152 static int		long_increment_overflow(long * number, int delta);
153 static int		long_normalize_overflow(long * tensptr,
154 				int * unitsptr, int base);
155 static int		normalize_overflow(int * tensptr, int * unitsptr,
156 				int base);
157 static void		settzname(void);
158 static time_t		time1(struct tm * tmp,
159 				struct tm * (*funcp)(const time_t *,
160 				long, struct tm *),
161 				long offset);
162 static time_t		time2(struct tm *tmp,
163 				struct tm * (*funcp)(const time_t *,
164 				long, struct tm*),
165 				long offset, int * okayp);
166 static time_t		time2sub(struct tm *tmp,
167 				struct tm * (*funcp)(const time_t *,
168 				long, struct tm*),
169 				long offset, int * okayp, int do_norm_secs);
170 static struct tm *	timesub(const time_t * timep, long offset,
171 				const struct state * sp, struct tm * tmp);
172 static int		tmcomp(const struct tm * atmp,
173 				const struct tm * btmp);
174 static time_t		transtime(time_t janfirst, int year,
175 				const struct rule * rulep, long offset);
176 static int		typesequiv(const struct state * sp, int a, int b);
177 static int		tzload(const char * name, struct state * sp,
178 				int doextend);
179 static int		tzparse(const char * name, struct state * sp,
180 				int lastditch);
181 
182 #ifdef ALL_STATE
183 static struct state *	lclptr;
184 static struct state *	gmtptr;
185 #endif /* defined ALL_STATE */
186 
187 #ifndef ALL_STATE
188 static struct state	lclmem;
189 static struct state	gmtmem;
190 #define lclptr		(&lclmem)
191 #define gmtptr		(&gmtmem)
192 #endif /* State Farm */
193 
194 #ifndef TZ_STRLEN_MAX
195 #define TZ_STRLEN_MAX 255
196 #endif /* !defined TZ_STRLEN_MAX */
197 
198 static char		lcl_TZname[TZ_STRLEN_MAX + 1];
199 static int		lcl_is_set;
200 static int		gmt_is_set;
201 _THREAD_PRIVATE_MUTEX(lcl);
202 _THREAD_PRIVATE_MUTEX(gmt);
203 
204 char *			tzname[2] = {
205 	wildabbr,
206 	wildabbr
207 };
208 
209 /*
210 ** Section 4.12.3 of X3.159-1989 requires that
211 **	Except for the strftime function, these functions [asctime,
212 **	ctime, gmtime, localtime] return values in one of two static
213 **	objects: a broken-down time structure and an array of char.
214 ** Thanks to Paul Eggert for noting this.
215 */
216 
217 static struct tm	tm;
218 
219 #ifdef USG_COMPAT
220 time_t			timezone = 0;
221 int			daylight = 0;
222 #endif /* defined USG_COMPAT */
223 
224 #ifdef ALTZONE
225 time_t			altzone = 0;
226 #endif /* defined ALTZONE */
227 
228 static long
229 detzcode(codep)
230 const char * const	codep;
231 {
232 	register long	result;
233 	register int	i;
234 
235 	result = (codep[0] & 0x80) ? ~0L : 0;
236 	for (i = 0; i < 4; ++i)
237 		result = (result << 8) | (codep[i] & 0xff);
238 	return result;
239 }
240 
241 static time_t
242 detzcode64(codep)
243 const char * const	codep;
244 {
245 	register time_t	result;
246 	register int	i;
247 
248 	result = (codep[0] & 0x80) ?  (~(int_fast64_t) 0) : 0;
249 	for (i = 0; i < 8; ++i)
250 		result = result * 256 + (codep[i] & 0xff);
251 	return result;
252 }
253 
254 static void
255 settzname(void)
256 {
257 	register struct state * const	sp = lclptr;
258 	register int			i;
259 
260 	tzname[0] = wildabbr;
261 	tzname[1] = wildabbr;
262 #ifdef USG_COMPAT
263 	daylight = 0;
264 	timezone = 0;
265 #endif /* defined USG_COMPAT */
266 #ifdef ALTZONE
267 	altzone = 0;
268 #endif /* defined ALTZONE */
269 #ifdef ALL_STATE
270 	if (sp == NULL) {
271 		tzname[0] = tzname[1] = (char *)gmt;
272 		return;
273 	}
274 #endif /* defined ALL_STATE */
275 	/*
276 	** And to get the latest zone names into tzname. . .
277 	*/
278 	for (i = 0; i < sp->timecnt; ++i) {
279 		register const struct ttinfo * const	ttisp =
280 							&sp->ttis[
281 								sp->types[i]];
282 
283 		tzname[ttisp->tt_isdst] =
284 			&sp->chars[ttisp->tt_abbrind];
285 #ifdef USG_COMPAT
286 		if (ttisp->tt_isdst)
287 			daylight = 1;
288 		if (!ttisp->tt_isdst)
289 			timezone = -(ttisp->tt_gmtoff);
290 #endif /* defined USG_COMPAT */
291 #ifdef ALTZONE
292 		if (ttisp->tt_isdst)
293 			altzone = -(ttisp->tt_gmtoff);
294 #endif /* defined ALTZONE */
295 	}
296 	/*
297 	** Finally, scrub the abbreviations.
298 	** First, replace bogus characters.
299 	*/
300 	for (i = 0; i < sp->charcnt; ++i)
301 		if (strchr(TZ_ABBR_CHAR_SET, sp->chars[i]) == NULL)
302 			sp->chars[i] = TZ_ABBR_ERR_CHAR;
303 	/*
304 	** Second, truncate long abbreviations.
305 	*/
306 	for (i = 0; i < sp->typecnt; ++i) {
307 		register const struct ttinfo * const	ttisp = &sp->ttis[i];
308 		register char *				cp = &sp->chars[ttisp->tt_abbrind];
309 
310 		if (strlen(cp) > TZ_ABBR_MAX_LEN &&
311 			strcmp(cp, GRANDPARENTED) != 0)
312 				*(cp + TZ_ABBR_MAX_LEN) = '\0';
313 	}
314 }
315 
316 static int
317 differ_by_repeat(t1, t0)
318 const time_t	t1;
319 const time_t	t0;
320 {
321 	if (TYPE_INTEGRAL(time_t) &&
322 		TYPE_BIT(time_t) - TYPE_SIGNED(time_t) < SECSPERREPEAT_BITS)
323 			return 0;
324 	return (int64_t)t1 - t0 == SECSPERREPEAT;
325 }
326 
327 static int
328 tzload(name, sp, doextend)
329 register const char *		name;
330 register struct state * const	sp;
331 register const int		doextend;
332 {
333 	register const char *		p;
334 	register int			i;
335 	register int			fid;
336 	register int			stored;
337 	register int			nread;
338 	typedef union {
339 		struct tzhead	tzhead;
340 		char		buf[2 * sizeof(struct tzhead) +
341 					2 * sizeof *sp +
342 					4 * TZ_MAX_TIMES];
343 	} u_t;
344 #ifdef ALL_STATE
345 	register u_t *			up;
346 
347 	up = (u_t *) calloc(1, sizeof *up);
348 	if (up == NULL)
349 		return -1;
350 #else /* !defined ALL_STATE */
351 	u_t				u;
352 	register u_t * const		up = &u;
353 #endif /* !defined ALL_STATE */
354 
355 	sp->goback = sp->goahead = FALSE;
356 	if (name != NULL && issetugid() != 0)
357 		if ((name[0] == ':' && (strchr(name, '/') || strstr(name, ".."))) ||
358 		    name[0] == '/' || strchr(name, '.'))
359 			name = NULL;
360 	if (name == NULL && (name = TZDEFAULT) == NULL)
361 		goto oops;
362 	{
363 		register int	doaccess;
364 		/*
365 		** Section 4.9.1 of the C standard says that
366 		** "FILENAME_MAX expands to an integral constant expression
367 		** that is the size needed for an array of char large enough
368 		** to hold the longest file name string that the implementation
369 		** guarantees can be opened."
370 		*/
371 		char		fullname[FILENAME_MAX];
372 
373 		if (name[0] == ':')
374 			++name;
375 		doaccess = name[0] == '/';
376 		if (!doaccess) {
377 			if ((p = TZDIR) == NULL)
378 				goto oops;
379 			if ((strlen(p) + strlen(name) + 1) >= sizeof fullname)
380 				goto oops;
381 			(void) strlcpy(fullname, p, sizeof fullname);
382 			(void) strlcat(fullname, "/", sizeof fullname);
383 			(void) strlcat(fullname, name, sizeof fullname);
384 			/*
385 			** Set doaccess if '.' (as in "../") shows up in name.
386 			*/
387 			if (strchr(name, '.') != NULL)
388 				doaccess = TRUE;
389 			name = fullname;
390 		}
391 		if (doaccess && access(name, R_OK) != 0)
392 			goto oops;
393 		if ((fid = open(name, OPEN_MODE)) == -1)
394 			goto oops;
395 	}
396 	nread = read(fid, up->buf, sizeof up->buf);
397 	if (close(fid) < 0 || nread <= 0)
398 		goto oops;
399 	for (stored = 4; stored <= 8; stored *= 2) {
400 		int		ttisstdcnt;
401 		int		ttisgmtcnt;
402 
403 		ttisstdcnt = (int) detzcode(up->tzhead.tzh_ttisstdcnt);
404 		ttisgmtcnt = (int) detzcode(up->tzhead.tzh_ttisgmtcnt);
405 		sp->leapcnt = (int) detzcode(up->tzhead.tzh_leapcnt);
406 		sp->timecnt = (int) detzcode(up->tzhead.tzh_timecnt);
407 		sp->typecnt = (int) detzcode(up->tzhead.tzh_typecnt);
408 		sp->charcnt = (int) detzcode(up->tzhead.tzh_charcnt);
409 		p = up->tzhead.tzh_charcnt + sizeof up->tzhead.tzh_charcnt;
410 		if (sp->leapcnt < 0 || sp->leapcnt > TZ_MAX_LEAPS ||
411 			sp->typecnt <= 0 || sp->typecnt > TZ_MAX_TYPES ||
412 			sp->timecnt < 0 || sp->timecnt > TZ_MAX_TIMES ||
413 			sp->charcnt < 0 || sp->charcnt > TZ_MAX_CHARS ||
414 			(ttisstdcnt != sp->typecnt && ttisstdcnt != 0) ||
415 			(ttisgmtcnt != sp->typecnt && ttisgmtcnt != 0))
416 				goto oops;
417 		if (nread - (p - up->buf) <
418 			sp->timecnt * stored +		/* ats */
419 			sp->timecnt +			/* types */
420 			sp->typecnt * 6 +		/* ttinfos */
421 			sp->charcnt +			/* chars */
422 			sp->leapcnt * (stored + 4) +	/* lsinfos */
423 			ttisstdcnt +			/* ttisstds */
424 			ttisgmtcnt)			/* ttisgmts */
425 				goto oops;
426 		for (i = 0; i < sp->timecnt; ++i) {
427 			sp->ats[i] = (stored == 4) ?
428 				detzcode(p) : detzcode64(p);
429 			p += stored;
430 		}
431 		for (i = 0; i < sp->timecnt; ++i) {
432 			sp->types[i] = (unsigned char) *p++;
433 			if (sp->types[i] >= sp->typecnt)
434 				goto oops;
435 		}
436 		for (i = 0; i < sp->typecnt; ++i) {
437 			register struct ttinfo *	ttisp;
438 
439 			ttisp = &sp->ttis[i];
440 			ttisp->tt_gmtoff = detzcode(p);
441 			p += 4;
442 			ttisp->tt_isdst = (unsigned char) *p++;
443 			if (ttisp->tt_isdst != 0 && ttisp->tt_isdst != 1)
444 				goto oops;
445 			ttisp->tt_abbrind = (unsigned char) *p++;
446 			if (ttisp->tt_abbrind < 0 ||
447 				ttisp->tt_abbrind > sp->charcnt)
448 					goto oops;
449 		}
450 		for (i = 0; i < sp->charcnt; ++i)
451 			sp->chars[i] = *p++;
452 		sp->chars[i] = '\0';	/* ensure '\0' at end */
453 		for (i = 0; i < sp->leapcnt; ++i) {
454 			register struct lsinfo *	lsisp;
455 
456 			lsisp = &sp->lsis[i];
457 			lsisp->ls_trans = (stored == 4) ?
458 				detzcode(p) : detzcode64(p);
459 			p += stored;
460 			lsisp->ls_corr = detzcode(p);
461 			p += 4;
462 		}
463 		for (i = 0; i < sp->typecnt; ++i) {
464 			register struct ttinfo *	ttisp;
465 
466 			ttisp = &sp->ttis[i];
467 			if (ttisstdcnt == 0)
468 				ttisp->tt_ttisstd = FALSE;
469 			else {
470 				ttisp->tt_ttisstd = *p++;
471 				if (ttisp->tt_ttisstd != TRUE &&
472 					ttisp->tt_ttisstd != FALSE)
473 						goto oops;
474 			}
475 		}
476 		for (i = 0; i < sp->typecnt; ++i) {
477 			register struct ttinfo *	ttisp;
478 
479 			ttisp = &sp->ttis[i];
480 			if (ttisgmtcnt == 0)
481 				ttisp->tt_ttisgmt = FALSE;
482 			else {
483 				ttisp->tt_ttisgmt = *p++;
484 				if (ttisp->tt_ttisgmt != TRUE &&
485 					ttisp->tt_ttisgmt != FALSE)
486 						goto oops;
487 			}
488 		}
489 		/*
490 		** Out-of-sort ats should mean we're running on a
491 		** signed time_t system but using a data file with
492 		** unsigned values (or vice versa).
493 		*/
494 		for (i = 0; i < sp->timecnt - 2; ++i)
495 			if (sp->ats[i] > sp->ats[i + 1]) {
496 				++i;
497 				if (TYPE_SIGNED(time_t)) {
498 					/*
499 					** Ignore the end (easy).
500 					*/
501 					sp->timecnt = i;
502 				} else {
503 					/*
504 					** Ignore the beginning (harder).
505 					*/
506 					register int	j;
507 
508 					for (j = 0; j + i < sp->timecnt; ++j) {
509 						sp->ats[j] = sp->ats[j + i];
510 						sp->types[j] = sp->types[j + i];
511 					}
512 					sp->timecnt = j;
513 				}
514 				break;
515 			}
516 		/*
517 		** If this is an old file, we're done.
518 		*/
519 		if (up->tzhead.tzh_version[0] == '\0')
520 			break;
521 		nread -= p - up->buf;
522 		for (i = 0; i < nread; ++i)
523 			up->buf[i] = p[i];
524 		/*
525 		** If this is a narrow integer time_t system, we're done.
526 		*/
527 		if (stored >= (int) sizeof(time_t) && TYPE_INTEGRAL(time_t))
528 			break;
529 	}
530 	if (doextend && nread > 2 &&
531 		up->buf[0] == '\n' && up->buf[nread - 1] == '\n' &&
532 		sp->typecnt + 2 <= TZ_MAX_TYPES) {
533 			struct state	ts;
534 			register int	result;
535 
536 			up->buf[nread - 1] = '\0';
537 			result = tzparse(&up->buf[1], &ts, FALSE);
538 			if (result == 0 && ts.typecnt == 2 &&
539 				sp->charcnt + ts.charcnt <= TZ_MAX_CHARS) {
540 					for (i = 0; i < 2; ++i)
541 						ts.ttis[i].tt_abbrind +=
542 							sp->charcnt;
543 					for (i = 0; i < ts.charcnt; ++i)
544 						sp->chars[sp->charcnt++] =
545 							ts.chars[i];
546 					i = 0;
547 					while (i < ts.timecnt &&
548 						ts.ats[i] <=
549 						sp->ats[sp->timecnt - 1])
550 							++i;
551 					while (i < ts.timecnt &&
552 					    sp->timecnt < TZ_MAX_TIMES) {
553 						sp->ats[sp->timecnt] =
554 							ts.ats[i];
555 						sp->types[sp->timecnt] =
556 							sp->typecnt +
557 							ts.types[i];
558 						++sp->timecnt;
559 						++i;
560 					}
561 					sp->ttis[sp->typecnt++] = ts.ttis[0];
562 					sp->ttis[sp->typecnt++] = ts.ttis[1];
563 			}
564 	}
565 	if (sp->timecnt > 1) {
566 		for (i = 1; i < sp->timecnt; ++i)
567 			if (typesequiv(sp, sp->types[i], sp->types[0]) &&
568 				differ_by_repeat(sp->ats[i], sp->ats[0])) {
569 					sp->goback = TRUE;
570 					break;
571 				}
572 		for (i = sp->timecnt - 2; i >= 0; --i)
573 			if (typesequiv(sp, sp->types[sp->timecnt - 1],
574 				sp->types[i]) &&
575 				differ_by_repeat(sp->ats[sp->timecnt - 1],
576 				sp->ats[i])) {
577 					sp->goahead = TRUE;
578 					break;
579 		}
580 	}
581 #ifdef ALL_STATE
582 	(void) free((void *) up);
583 #endif /* defined ALL_STATE */
584 	return 0;
585 oops:
586 #ifdef ALL_STATE
587 	(void) free((void *) up);
588 #endif /* defined ALL_STATE */
589 	return -1;
590 }
591 
592 static int
593 typesequiv(sp, a, b)
594 const struct state * const	sp;
595 const int			a;
596 const int			b;
597 {
598 	register int	result;
599 
600 	if (sp == NULL ||
601 		a < 0 || a >= sp->typecnt ||
602 		b < 0 || b >= sp->typecnt)
603 			result = FALSE;
604 	else {
605 		register const struct ttinfo *	ap = &sp->ttis[a];
606 		register const struct ttinfo *	bp = &sp->ttis[b];
607 		result = ap->tt_gmtoff == bp->tt_gmtoff &&
608 			ap->tt_isdst == bp->tt_isdst &&
609 			ap->tt_ttisstd == bp->tt_ttisstd &&
610 			ap->tt_ttisgmt == bp->tt_ttisgmt &&
611 			strcmp(&sp->chars[ap->tt_abbrind],
612 			&sp->chars[bp->tt_abbrind]) == 0;
613 	}
614 	return result;
615 }
616 
617 static const int	mon_lengths[2][MONSPERYEAR] = {
618 	{ 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 },
619 	{ 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }
620 };
621 
622 static const int	year_lengths[2] = {
623 	DAYSPERNYEAR, DAYSPERLYEAR
624 };
625 
626 /*
627 ** Given a pointer into a time zone string, scan until a character that is not
628 ** a valid character in a zone name is found. Return a pointer to that
629 ** character.
630 */
631 
632 static const char *
633 getzname(strp)
634 register const char *	strp;
635 {
636 	register char	c;
637 
638 	while ((c = *strp) != '\0' && !is_digit(c) && c != ',' && c != '-' &&
639 		c != '+')
640 			++strp;
641 	return strp;
642 }
643 
644 /*
645 ** Given a pointer into an extended time zone string, scan until the ending
646 ** delimiter of the zone name is located. Return a pointer to the delimiter.
647 **
648 ** As with getzname above, the legal character set is actually quite
649 ** restricted, with other characters producing undefined results.
650 ** We don't do any checking here; checking is done later in common-case code.
651 */
652 
653 static const char *
654 getqzname(register const char *strp, const int delim)
655 {
656 	register int	c;
657 
658 	while ((c = *strp) != '\0' && c != delim)
659 		++strp;
660 	return strp;
661 }
662 
663 /*
664 ** Given a pointer into a time zone string, extract a number from that string.
665 ** Check that the number is within a specified range; if it is not, return
666 ** NULL.
667 ** Otherwise, return a pointer to the first character not part of the number.
668 */
669 
670 static const char *
671 getnum(strp, nump, min, max)
672 register const char *	strp;
673 int * const		nump;
674 const int		min;
675 const int		max;
676 {
677 	register char	c;
678 	register int	num;
679 
680 	if (strp == NULL || !is_digit(c = *strp))
681 		return NULL;
682 	num = 0;
683 	do {
684 		num = num * 10 + (c - '0');
685 		if (num > max)
686 			return NULL;	/* illegal value */
687 		c = *++strp;
688 	} while (is_digit(c));
689 	if (num < min)
690 		return NULL;		/* illegal value */
691 	*nump = num;
692 	return strp;
693 }
694 
695 /*
696 ** Given a pointer into a time zone string, extract a number of seconds,
697 ** in hh[:mm[:ss]] form, from the string.
698 ** If any error occurs, return NULL.
699 ** Otherwise, return a pointer to the first character not part of the number
700 ** of seconds.
701 */
702 
703 static const char *
704 getsecs(strp, secsp)
705 register const char *	strp;
706 long * const		secsp;
707 {
708 	int	num;
709 
710 	/*
711 	** `HOURSPERDAY * DAYSPERWEEK - 1' allows quasi-Posix rules like
712 	** "M10.4.6/26", which does not conform to Posix,
713 	** but which specifies the equivalent of
714 	** ``02:00 on the first Sunday on or after 23 Oct''.
715 	*/
716 	strp = getnum(strp, &num, 0, HOURSPERDAY * DAYSPERWEEK - 1);
717 	if (strp == NULL)
718 		return NULL;
719 	*secsp = num * (long) SECSPERHOUR;
720 	if (*strp == ':') {
721 		++strp;
722 		strp = getnum(strp, &num, 0, MINSPERHOUR - 1);
723 		if (strp == NULL)
724 			return NULL;
725 		*secsp += num * SECSPERMIN;
726 		if (*strp == ':') {
727 			++strp;
728 			/* `SECSPERMIN' allows for leap seconds. */
729 			strp = getnum(strp, &num, 0, SECSPERMIN);
730 			if (strp == NULL)
731 				return NULL;
732 			*secsp += num;
733 		}
734 	}
735 	return strp;
736 }
737 
738 /*
739 ** Given a pointer into a time zone string, extract an offset, in
740 ** [+-]hh[:mm[:ss]] form, from the string.
741 ** If any error occurs, return NULL.
742 ** Otherwise, return a pointer to the first character not part of the time.
743 */
744 
745 static const char *
746 getoffset(strp, offsetp)
747 register const char *	strp;
748 long * const		offsetp;
749 {
750 	register int	neg = 0;
751 
752 	if (*strp == '-') {
753 		neg = 1;
754 		++strp;
755 	} else if (*strp == '+')
756 		++strp;
757 	strp = getsecs(strp, offsetp);
758 	if (strp == NULL)
759 		return NULL;		/* illegal time */
760 	if (neg)
761 		*offsetp = -*offsetp;
762 	return strp;
763 }
764 
765 /*
766 ** Given a pointer into a time zone string, extract a rule in the form
767 ** date[/time]. See POSIX section 8 for the format of "date" and "time".
768 ** If a valid rule is not found, return NULL.
769 ** Otherwise, return a pointer to the first character not part of the rule.
770 */
771 
772 static const char *
773 getrule(strp, rulep)
774 const char *			strp;
775 register struct rule * const	rulep;
776 {
777 	if (*strp == 'J') {
778 		/*
779 		** Julian day.
780 		*/
781 		rulep->r_type = JULIAN_DAY;
782 		++strp;
783 		strp = getnum(strp, &rulep->r_day, 1, DAYSPERNYEAR);
784 	} else if (*strp == 'M') {
785 		/*
786 		** Month, week, day.
787 		*/
788 		rulep->r_type = MONTH_NTH_DAY_OF_WEEK;
789 		++strp;
790 		strp = getnum(strp, &rulep->r_mon, 1, MONSPERYEAR);
791 		if (strp == NULL)
792 			return NULL;
793 		if (*strp++ != '.')
794 			return NULL;
795 		strp = getnum(strp, &rulep->r_week, 1, 5);
796 		if (strp == NULL)
797 			return NULL;
798 		if (*strp++ != '.')
799 			return NULL;
800 		strp = getnum(strp, &rulep->r_day, 0, DAYSPERWEEK - 1);
801 	} else if (is_digit(*strp)) {
802 		/*
803 		** Day of year.
804 		*/
805 		rulep->r_type = DAY_OF_YEAR;
806 		strp = getnum(strp, &rulep->r_day, 0, DAYSPERLYEAR - 1);
807 	} else	return NULL;		/* invalid format */
808 	if (strp == NULL)
809 		return NULL;
810 	if (*strp == '/') {
811 		/*
812 		** Time specified.
813 		*/
814 		++strp;
815 		strp = getsecs(strp, &rulep->r_time);
816 	} else	rulep->r_time = 2 * SECSPERHOUR;	/* default = 2:00:00 */
817 	return strp;
818 }
819 
820 /*
821 ** Given the Epoch-relative time of January 1, 00:00:00 UTC, in a year, the
822 ** year, a rule, and the offset from UTC at the time that rule takes effect,
823 ** calculate the Epoch-relative time that rule takes effect.
824 */
825 
826 static time_t
827 transtime(janfirst, year, rulep, offset)
828 const time_t				janfirst;
829 const int				year;
830 register const struct rule * const	rulep;
831 const long				offset;
832 {
833 	register int	leapyear;
834 	register time_t	value;
835 	register int	i;
836 	int		d, m1, yy0, yy1, yy2, dow;
837 
838 	INITIALIZE(value);
839 	leapyear = isleap(year);
840 	switch (rulep->r_type) {
841 
842 	case JULIAN_DAY:
843 		/*
844 		** Jn - Julian day, 1 == January 1, 60 == March 1 even in leap
845 		** years.
846 		** In non-leap years, or if the day number is 59 or less, just
847 		** add SECSPERDAY times the day number-1 to the time of
848 		** January 1, midnight, to get the day.
849 		*/
850 		value = janfirst + (rulep->r_day - 1) * SECSPERDAY;
851 		if (leapyear && rulep->r_day >= 60)
852 			value += SECSPERDAY;
853 		break;
854 
855 	case DAY_OF_YEAR:
856 		/*
857 		** n - day of year.
858 		** Just add SECSPERDAY times the day number to the time of
859 		** January 1, midnight, to get the day.
860 		*/
861 		value = janfirst + rulep->r_day * SECSPERDAY;
862 		break;
863 
864 	case MONTH_NTH_DAY_OF_WEEK:
865 		/*
866 		** Mm.n.d - nth "dth day" of month m.
867 		*/
868 		value = janfirst;
869 		for (i = 0; i < rulep->r_mon - 1; ++i)
870 			value += mon_lengths[leapyear][i] * SECSPERDAY;
871 
872 		/*
873 		** Use Zeller's Congruence to get day-of-week of first day of
874 		** month.
875 		*/
876 		m1 = (rulep->r_mon + 9) % 12 + 1;
877 		yy0 = (rulep->r_mon <= 2) ? (year - 1) : year;
878 		yy1 = yy0 / 100;
879 		yy2 = yy0 % 100;
880 		dow = ((26 * m1 - 2) / 10 +
881 			1 + yy2 + yy2 / 4 + yy1 / 4 - 2 * yy1) % 7;
882 		if (dow < 0)
883 			dow += DAYSPERWEEK;
884 
885 		/*
886 		** "dow" is the day-of-week of the first day of the month. Get
887 		** the day-of-month (zero-origin) of the first "dow" day of the
888 		** month.
889 		*/
890 		d = rulep->r_day - dow;
891 		if (d < 0)
892 			d += DAYSPERWEEK;
893 		for (i = 1; i < rulep->r_week; ++i) {
894 			if (d + DAYSPERWEEK >=
895 				mon_lengths[leapyear][rulep->r_mon - 1])
896 					break;
897 			d += DAYSPERWEEK;
898 		}
899 
900 		/*
901 		** "d" is the day-of-month (zero-origin) of the day we want.
902 		*/
903 		value += d * SECSPERDAY;
904 		break;
905 	}
906 
907 	/*
908 	** "value" is the Epoch-relative time of 00:00:00 UTC on the day in
909 	** question. To get the Epoch-relative time of the specified local
910 	** time on that day, add the transition time and the current offset
911 	** from UTC.
912 	*/
913 	return value + rulep->r_time + offset;
914 }
915 
916 /*
917 ** Given a POSIX section 8-style TZ string, fill in the rule tables as
918 ** appropriate.
919 */
920 
921 static int
922 tzparse(name, sp, lastditch)
923 const char *			name;
924 register struct state * const	sp;
925 const int			lastditch;
926 {
927 	const char *			stdname;
928 	const char *			dstname;
929 	size_t				stdlen;
930 	size_t				dstlen;
931 	long				stdoffset;
932 	long				dstoffset;
933 	register time_t *		atp;
934 	register unsigned char *	typep;
935 	register char *			cp;
936 	register int			load_result;
937 	static struct ttinfo		zttinfo;
938 
939 	INITIALIZE(dstname);
940 	stdname = name;
941 	if (lastditch) {
942 		stdlen = strlen(name);	/* length of standard zone name */
943 		name += stdlen;
944 		if (stdlen >= sizeof sp->chars)
945 			stdlen = (sizeof sp->chars) - 1;
946 		stdoffset = 0;
947 	} else {
948 		if (*name == '<') {
949 			name++;
950 			stdname = name;
951 			name = getqzname(name, '>');
952 			if (*name != '>')
953 				return (-1);
954 			stdlen = name - stdname;
955 			name++;
956 		} else {
957 			name = getzname(name);
958 			stdlen = name - stdname;
959 		}
960 		if (*name == '\0')
961 			return -1;
962 		name = getoffset(name, &stdoffset);
963 		if (name == NULL)
964 			return -1;
965 	}
966 	load_result = tzload(TZDEFRULES, sp, FALSE);
967 	if (load_result != 0)
968 		sp->leapcnt = 0;		/* so, we're off a little */
969 	if (*name != '\0') {
970 		if (*name == '<') {
971 			dstname = ++name;
972 			name = getqzname(name, '>');
973 			if (*name != '>')
974 				return -1;
975 			dstlen = name - dstname;
976 			name++;
977 		} else {
978 			dstname = name;
979 			name = getzname(name);
980 			dstlen = name - dstname; /* length of DST zone name */
981 		}
982 		if (*name != '\0' && *name != ',' && *name != ';') {
983 			name = getoffset(name, &dstoffset);
984 			if (name == NULL)
985 				return -1;
986 		} else	dstoffset = stdoffset - SECSPERHOUR;
987 		if (*name == '\0' && load_result != 0)
988 			name = TZDEFRULESTRING;
989 		if (*name == ',' || *name == ';') {
990 			struct rule	start;
991 			struct rule	end;
992 			register int	year;
993 			register time_t	janfirst;
994 			time_t		starttime;
995 			time_t		endtime;
996 
997 			++name;
998 			if ((name = getrule(name, &start)) == NULL)
999 				return -1;
1000 			if (*name++ != ',')
1001 				return -1;
1002 			if ((name = getrule(name, &end)) == NULL)
1003 				return -1;
1004 			if (*name != '\0')
1005 				return -1;
1006 			sp->typecnt = 2;	/* standard time and DST */
1007 			/*
1008 			** Two transitions per year, from EPOCH_YEAR forward.
1009 			*/
1010 			sp->ttis[0] = sp->ttis[1] = zttinfo;
1011 			sp->ttis[0].tt_gmtoff = -dstoffset;
1012 			sp->ttis[0].tt_isdst = 1;
1013 			sp->ttis[0].tt_abbrind = stdlen + 1;
1014 			sp->ttis[1].tt_gmtoff = -stdoffset;
1015 			sp->ttis[1].tt_isdst = 0;
1016 			sp->ttis[1].tt_abbrind = 0;
1017 			atp = sp->ats;
1018 			typep = sp->types;
1019 			janfirst = 0;
1020 			sp->timecnt = 0;
1021 			for (year = EPOCH_YEAR;
1022 			    sp->timecnt + 2 <= TZ_MAX_TIMES;
1023 			    ++year) {
1024 			    	time_t	newfirst;
1025 
1026 				starttime = transtime(janfirst, year, &start,
1027 					stdoffset);
1028 				endtime = transtime(janfirst, year, &end,
1029 					dstoffset);
1030 				if (starttime > endtime) {
1031 					*atp++ = endtime;
1032 					*typep++ = 1;	/* DST ends */
1033 					*atp++ = starttime;
1034 					*typep++ = 0;	/* DST begins */
1035 				} else {
1036 					*atp++ = starttime;
1037 					*typep++ = 0;	/* DST begins */
1038 					*atp++ = endtime;
1039 					*typep++ = 1;	/* DST ends */
1040 				}
1041 				sp->timecnt += 2;
1042 				newfirst = janfirst;
1043 				newfirst += year_lengths[isleap(year)] *
1044 					SECSPERDAY;
1045 				if (newfirst <= janfirst)
1046 					break;
1047 				janfirst = newfirst;
1048 			}
1049 		} else {
1050 			register long	theirstdoffset;
1051 			register long	theirdstoffset;
1052 			register long	theiroffset;
1053 			register int	isdst;
1054 			register int	i;
1055 			register int	j;
1056 
1057 			if (*name != '\0')
1058 				return -1;
1059 			/*
1060 			** Initial values of theirstdoffset and theirdstoffset.
1061 			*/
1062 			theirstdoffset = 0;
1063 			for (i = 0; i < sp->timecnt; ++i) {
1064 				j = sp->types[i];
1065 				if (!sp->ttis[j].tt_isdst) {
1066 					theirstdoffset =
1067 						-sp->ttis[j].tt_gmtoff;
1068 					break;
1069 				}
1070 			}
1071 			theirdstoffset = 0;
1072 			for (i = 0; i < sp->timecnt; ++i) {
1073 				j = sp->types[i];
1074 				if (sp->ttis[j].tt_isdst) {
1075 					theirdstoffset =
1076 						-sp->ttis[j].tt_gmtoff;
1077 					break;
1078 				}
1079 			}
1080 			/*
1081 			** Initially we're assumed to be in standard time.
1082 			*/
1083 			isdst = FALSE;
1084 			theiroffset = theirstdoffset;
1085 			/*
1086 			** Now juggle transition times and types
1087 			** tracking offsets as you do.
1088 			*/
1089 			for (i = 0; i < sp->timecnt; ++i) {
1090 				j = sp->types[i];
1091 				sp->types[i] = sp->ttis[j].tt_isdst;
1092 				if (sp->ttis[j].tt_ttisgmt) {
1093 					/* No adjustment to transition time */
1094 				} else {
1095 					/*
1096 					** If summer time is in effect, and the
1097 					** transition time was not specified as
1098 					** standard time, add the summer time
1099 					** offset to the transition time;
1100 					** otherwise, add the standard time
1101 					** offset to the transition time.
1102 					*/
1103 					/*
1104 					** Transitions from DST to DDST
1105 					** will effectively disappear since
1106 					** POSIX provides for only one DST
1107 					** offset.
1108 					*/
1109 					if (isdst && !sp->ttis[j].tt_ttisstd) {
1110 						sp->ats[i] += dstoffset -
1111 							theirdstoffset;
1112 					} else {
1113 						sp->ats[i] += stdoffset -
1114 							theirstdoffset;
1115 					}
1116 				}
1117 				theiroffset = -sp->ttis[j].tt_gmtoff;
1118 				if (sp->ttis[j].tt_isdst)
1119 					theirdstoffset = theiroffset;
1120 				else	theirstdoffset = theiroffset;
1121 			}
1122 			/*
1123 			** Finally, fill in ttis.
1124 			*/
1125 			sp->ttis[0] = sp->ttis[1] = zttinfo;
1126 			sp->ttis[0].tt_gmtoff = -stdoffset;
1127 			sp->ttis[0].tt_isdst = FALSE;
1128 			sp->ttis[0].tt_abbrind = 0;
1129 			sp->ttis[1].tt_gmtoff = -dstoffset;
1130 			sp->ttis[1].tt_isdst = TRUE;
1131 			sp->ttis[1].tt_abbrind = stdlen + 1;
1132 			sp->typecnt = 2;
1133 		}
1134 	} else {
1135 		dstlen = 0;
1136 		sp->typecnt = 1;		/* only standard time */
1137 		sp->timecnt = 0;
1138 		sp->ttis[0] = zttinfo;
1139 		sp->ttis[0].tt_gmtoff = -stdoffset;
1140 		sp->ttis[0].tt_isdst = 0;
1141 		sp->ttis[0].tt_abbrind = 0;
1142 	}
1143 	sp->charcnt = stdlen + 1;
1144 	if (dstlen != 0)
1145 		sp->charcnt += dstlen + 1;
1146 	if ((size_t) sp->charcnt > sizeof sp->chars)
1147 		return -1;
1148 	cp = sp->chars;
1149 	strlcpy(cp, stdname, stdlen + 1);
1150 	cp += stdlen + 1;
1151 	if (dstlen != 0) {
1152 		strlcpy(cp, dstname, dstlen + 1);
1153 	}
1154 	return 0;
1155 }
1156 
1157 static void
1158 gmtload(sp)
1159 struct state * const	sp;
1160 {
1161 	if (tzload(gmt, sp, TRUE) != 0)
1162 		(void) tzparse(gmt, sp, TRUE);
1163 }
1164 static
1165 void
1166 tzsetwall_basic(void)
1167 {
1168 	if (lcl_is_set < 0)
1169 		return;
1170 	lcl_is_set = -1;
1171 
1172 #ifdef ALL_STATE
1173 	if (lclptr == NULL) {
1174 		lclptr = (struct state *) calloc(1, sizeof *lclptr);
1175 		if (lclptr == NULL) {
1176 			settzname();	/* all we can do */
1177 			return;
1178 		}
1179 	}
1180 #endif /* defined ALL_STATE */
1181 	if (tzload((char *) NULL, lclptr, TRUE) != 0)
1182 		gmtload(lclptr);
1183 	settzname();
1184 }
1185 
1186 #ifndef STD_INSPIRED
1187 /*
1188 ** A non-static declaration of tzsetwall in a system header file
1189 ** may cause a warning about this upcoming static declaration...
1190 */
1191 static
1192 #endif /* !defined STD_INSPIRED */
1193 void
1194 tzsetwall(void)
1195 {
1196 	_THREAD_PRIVATE_MUTEX_LOCK(lcl);
1197 	tzsetwall_basic();
1198 	_THREAD_PRIVATE_MUTEX_UNLOCK(lcl);
1199 }
1200 
1201 static
1202 void
1203 tzset_basic(void)
1204 {
1205 	register const char *	name;
1206 
1207 	name = getenv("TZ");
1208 	if (name == NULL) {
1209 		tzsetwall_basic();
1210 		return;
1211 	}
1212 
1213 	if (lcl_is_set > 0 && strcmp(lcl_TZname, name) == 0)
1214 		return;
1215 	lcl_is_set = strlen(name) < sizeof lcl_TZname;
1216 	if (lcl_is_set)
1217 		(void) strlcpy(lcl_TZname, name, sizeof lcl_TZname);
1218 
1219 #ifdef ALL_STATE
1220 	if (lclptr == NULL) {
1221 		lclptr = (struct state *) calloc(1, sizeof *lclptr);
1222 		if (lclptr == NULL) {
1223 			settzname();	/* all we can do */
1224 			return;
1225 		}
1226 	}
1227 #endif /* defined ALL_STATE */
1228 	if (*name == '\0') {
1229 		/*
1230 		** User wants it fast rather than right.
1231 		*/
1232 		lclptr->leapcnt = 0;		/* so, we're off a little */
1233 		lclptr->timecnt = 0;
1234 		lclptr->typecnt = 0;
1235 		lclptr->ttis[0].tt_isdst = 0;
1236 		lclptr->ttis[0].tt_gmtoff = 0;
1237 		lclptr->ttis[0].tt_abbrind = 0;
1238 		(void) strlcpy(lclptr->chars, gmt, sizeof lclptr->chars);
1239 	} else if (tzload(name, lclptr, TRUE) != 0)
1240 		if (name[0] == ':' || tzparse(name, lclptr, FALSE) != 0)
1241 			(void) gmtload(lclptr);
1242 	settzname();
1243 }
1244 
1245 void
1246 tzset(void)
1247 {
1248 	_THREAD_PRIVATE_MUTEX_LOCK(lcl);
1249 	tzset_basic();
1250 	_THREAD_PRIVATE_MUTEX_UNLOCK(lcl);
1251 }
1252 
1253 /*
1254 ** The easy way to behave "as if no library function calls" localtime
1255 ** is to not call it--so we drop its guts into "localsub", which can be
1256 ** freely called. (And no, the PANS doesn't require the above behavior--
1257 ** but it *is* desirable.)
1258 **
1259 ** The unused offset argument is for the benefit of mktime variants.
1260 */
1261 
1262 /*ARGSUSED*/
1263 static struct tm *
1264 localsub(timep, offset, tmp)
1265 const time_t * const	timep;
1266 const long		offset;
1267 struct tm * const	tmp;
1268 {
1269 	register struct state *		sp;
1270 	register const struct ttinfo *	ttisp;
1271 	register int			i;
1272 	register struct tm *		result;
1273 	const time_t			t = *timep;
1274 
1275 	sp = lclptr;
1276 #ifdef ALL_STATE
1277 	if (sp == NULL)
1278 		return gmtsub(timep, offset, tmp);
1279 #endif /* defined ALL_STATE */
1280 	if ((sp->goback && t < sp->ats[0]) ||
1281 		(sp->goahead && t > sp->ats[sp->timecnt - 1])) {
1282 			time_t			newt = t;
1283 			register time_t		seconds;
1284 			register time_t		tcycles;
1285 			register int_fast64_t	icycles;
1286 
1287 			if (t < sp->ats[0])
1288 				seconds = sp->ats[0] - t;
1289 			else	seconds = t - sp->ats[sp->timecnt - 1];
1290 			--seconds;
1291 			tcycles = seconds / YEARSPERREPEAT / AVGSECSPERYEAR;
1292 			++tcycles;
1293 			icycles = tcycles;
1294 			if (tcycles - icycles >= 1 || icycles - tcycles >= 1)
1295 				return NULL;
1296 			seconds = icycles;
1297 			seconds *= YEARSPERREPEAT;
1298 			seconds *= AVGSECSPERYEAR;
1299 			if (t < sp->ats[0])
1300 				newt += seconds;
1301 			else	newt -= seconds;
1302 			if (newt < sp->ats[0] ||
1303 				newt > sp->ats[sp->timecnt - 1])
1304 					return NULL;	/* "cannot happen" */
1305 			result = localsub(&newt, offset, tmp);
1306 			if (result == tmp) {
1307 				register time_t	newy;
1308 
1309 				newy = tmp->tm_year;
1310 				if (t < sp->ats[0])
1311 					newy -= icycles * YEARSPERREPEAT;
1312 				else	newy += icycles * YEARSPERREPEAT;
1313 				tmp->tm_year = newy;
1314 				if (tmp->tm_year != newy)
1315 					return NULL;
1316 			}
1317 			return result;
1318 	}
1319 	if (sp->timecnt == 0 || t < sp->ats[0]) {
1320 		i = 0;
1321 		while (sp->ttis[i].tt_isdst)
1322 			if (++i >= sp->typecnt) {
1323 				i = 0;
1324 				break;
1325 			}
1326 	} else {
1327 		register int	lo = 1;
1328 		register int	hi = sp->timecnt;
1329 
1330 		while (lo < hi) {
1331 			register int	mid = (lo + hi) >> 1;
1332 
1333 			if (t < sp->ats[mid])
1334 				hi = mid;
1335 			else	lo = mid + 1;
1336 		}
1337 		i = (int) sp->types[lo - 1];
1338 	}
1339 	ttisp = &sp->ttis[i];
1340 	/*
1341 	** To get (wrong) behavior that's compatible with System V Release 2.0
1342 	** you'd replace the statement below with
1343 	**	t += ttisp->tt_gmtoff;
1344 	**	timesub(&t, 0L, sp, tmp);
1345 	*/
1346 	result = timesub(&t, ttisp->tt_gmtoff, sp, tmp);
1347 	tmp->tm_isdst = ttisp->tt_isdst;
1348 	tzname[tmp->tm_isdst] = &sp->chars[ttisp->tt_abbrind];
1349 #ifdef TM_ZONE
1350 	tmp->TM_ZONE = &sp->chars[ttisp->tt_abbrind];
1351 #endif /* defined TM_ZONE */
1352 	return result;
1353 }
1354 
1355 /*
1356 ** Re-entrant version of localtime.
1357 */
1358 
1359 struct tm *
1360 localtime_r(timep, p_tm)
1361 const time_t * const	timep;
1362 struct tm *p_tm;
1363 {
1364 	_THREAD_PRIVATE_MUTEX_LOCK(lcl);
1365 	tzset_basic();
1366 	p_tm = localsub(timep, 0L, p_tm);
1367 	_THREAD_PRIVATE_MUTEX_UNLOCK(lcl);
1368 	return p_tm;
1369 }
1370 
1371 struct tm *
1372 localtime(timep)
1373 const time_t * const	timep;
1374 {
1375 	_THREAD_PRIVATE_KEY(localtime);
1376 	struct tm * p_tm = (struct tm*)_THREAD_PRIVATE(localtime, tm, NULL);
1377 
1378 	if (p_tm == NULL)
1379 		return NULL;
1380 	return localtime_r(timep, p_tm);
1381 }
1382 
1383 /*
1384 ** gmtsub is to gmtime as localsub is to localtime.
1385 */
1386 
1387 static struct tm *
1388 gmtsub(timep, offset, tmp)
1389 const time_t * const	timep;
1390 const long		offset;
1391 struct tm * const	tmp;
1392 {
1393 	register struct tm *	result;
1394 
1395 	_THREAD_PRIVATE_MUTEX_LOCK(gmt);
1396 	if (!gmt_is_set) {
1397 		gmt_is_set = TRUE;
1398 #ifdef ALL_STATE
1399 		gmtptr = (struct state *) calloc(1, sizeof *gmtptr);
1400 		if (gmtptr != NULL)
1401 #endif /* defined ALL_STATE */
1402 			gmtload(gmtptr);
1403 	}
1404 	_THREAD_PRIVATE_MUTEX_UNLOCK(gmt);
1405 	result = timesub(timep, offset, gmtptr, tmp);
1406 #ifdef TM_ZONE
1407 	/*
1408 	** Could get fancy here and deliver something such as
1409 	** "UTC+xxxx" or "UTC-xxxx" if offset is non-zero,
1410 	** but this is no time for a treasure hunt.
1411 	*/
1412 	if (offset != 0)
1413 		tmp->TM_ZONE = wildabbr;
1414 	else {
1415 #ifdef ALL_STATE
1416 		if (gmtptr == NULL)
1417 			tmp->TM_ZONE = (char *)gmt;
1418 		else	tmp->TM_ZONE = gmtptr->chars;
1419 #endif /* defined ALL_STATE */
1420 #ifndef ALL_STATE
1421 		tmp->TM_ZONE = gmtptr->chars;
1422 #endif /* State Farm */
1423 	}
1424 #endif /* defined TM_ZONE */
1425 	return result;
1426 }
1427 
1428 /*
1429 ** Re-entrant version of gmtime.
1430 */
1431 
1432 struct tm *
1433 gmtime_r(timep, p_tm)
1434 const time_t *		timep;
1435 struct tm *		p_tm;
1436 {
1437 	gmtsub(timep, 0L, p_tm);
1438 	return p_tm;
1439 }
1440 
1441 struct tm *
1442 gmtime(timep)
1443 const time_t * const	timep;
1444 {
1445 	_THREAD_PRIVATE_KEY(gmtime);
1446 	struct tm * p_tm = (struct tm*) _THREAD_PRIVATE(gmtime, tm, NULL);
1447 
1448 	if (p_tm == NULL)
1449 		return NULL;
1450 	return gmtime_r(timep, p_tm);
1451 
1452 }
1453 
1454 #ifdef STD_INSPIRED
1455 
1456 struct tm *
1457 offtime(timep, offset)
1458 const time_t * const	timep;
1459 const long		offset;
1460 {
1461 	return gmtsub(timep, offset, &tm);
1462 }
1463 
1464 #endif /* defined STD_INSPIRED */
1465 
1466 /*
1467 ** Return the number of leap years through the end of the given year
1468 ** where, to make the math easy, the answer for year zero is defined as zero.
1469 */
1470 
1471 static int
1472 leaps_thru_end_of(y)
1473 register const int	y;
1474 {
1475 	return (y >= 0) ? (y / 4 - y / 100 + y / 400) :
1476 		-(leaps_thru_end_of(-(y + 1)) + 1);
1477 }
1478 
1479 static struct tm *
1480 timesub(timep, offset, sp, tmp)
1481 const time_t * const			timep;
1482 const long				offset;
1483 register const struct state * const	sp;
1484 register struct tm * const		tmp;
1485 {
1486 	register const struct lsinfo *	lp;
1487 	register time_t			tdays;
1488 	register int			idays;	/* unsigned would be so 2003 */
1489 	register long			rem;
1490 	int				y;
1491 	register const int *		ip;
1492 	register long			corr;
1493 	register int			hit;
1494 	register int			i;
1495 
1496 	corr = 0;
1497 	hit = 0;
1498 #ifdef ALL_STATE
1499 	i = (sp == NULL) ? 0 : sp->leapcnt;
1500 #endif /* defined ALL_STATE */
1501 #ifndef ALL_STATE
1502 	i = sp->leapcnt;
1503 #endif /* State Farm */
1504 	while (--i >= 0) {
1505 		lp = &sp->lsis[i];
1506 		if (*timep >= lp->ls_trans) {
1507 			if (*timep == lp->ls_trans) {
1508 				hit = ((i == 0 && lp->ls_corr > 0) ||
1509 					lp->ls_corr > sp->lsis[i - 1].ls_corr);
1510 				if (hit)
1511 					while (i > 0 &&
1512 						sp->lsis[i].ls_trans ==
1513 						sp->lsis[i - 1].ls_trans + 1 &&
1514 						sp->lsis[i].ls_corr ==
1515 						sp->lsis[i - 1].ls_corr + 1) {
1516 							++hit;
1517 							--i;
1518 					}
1519 			}
1520 			corr = lp->ls_corr;
1521 			break;
1522 		}
1523 	}
1524 	y = EPOCH_YEAR;
1525 	tdays = *timep / SECSPERDAY;
1526 	rem = *timep - tdays * SECSPERDAY;
1527 	while (tdays < 0 || tdays >= year_lengths[isleap(y)]) {
1528 		int		newy;
1529 		register time_t	tdelta;
1530 		register int	idelta;
1531 		register int	leapdays;
1532 
1533 		tdelta = tdays / DAYSPERLYEAR;
1534 		idelta = tdelta;
1535 		if (tdelta - idelta >= 1 || idelta - tdelta >= 1)
1536 			return NULL;
1537 		if (idelta == 0)
1538 			idelta = (tdays < 0) ? -1 : 1;
1539 		newy = y;
1540 		if (increment_overflow(&newy, idelta))
1541 			return NULL;
1542 		leapdays = leaps_thru_end_of(newy - 1) -
1543 			leaps_thru_end_of(y - 1);
1544 		tdays -= ((time_t) newy - y) * DAYSPERNYEAR;
1545 		tdays -= leapdays;
1546 		y = newy;
1547 	}
1548 	{
1549 		register long	seconds;
1550 
1551 		seconds = tdays * SECSPERDAY + 0.5;
1552 		tdays = seconds / SECSPERDAY;
1553 		rem += seconds - tdays * SECSPERDAY;
1554 	}
1555 	/*
1556 	** Given the range, we can now fearlessly cast...
1557 	*/
1558 	idays = tdays;
1559 	rem += offset - corr;
1560 	while (rem < 0) {
1561 		rem += SECSPERDAY;
1562 		--idays;
1563 	}
1564 	while (rem >= SECSPERDAY) {
1565 		rem -= SECSPERDAY;
1566 		++idays;
1567 	}
1568 	while (idays < 0) {
1569 		if (increment_overflow(&y, -1))
1570 			return NULL;
1571 		idays += year_lengths[isleap(y)];
1572 	}
1573 	while (idays >= year_lengths[isleap(y)]) {
1574 		idays -= year_lengths[isleap(y)];
1575 		if (increment_overflow(&y, 1))
1576 			return NULL;
1577 	}
1578 	tmp->tm_year = y;
1579 	if (increment_overflow(&tmp->tm_year, -TM_YEAR_BASE))
1580 		return NULL;
1581 	tmp->tm_yday = idays;
1582 	/*
1583 	** The "extra" mods below avoid overflow problems.
1584 	*/
1585 	tmp->tm_wday = EPOCH_WDAY +
1586 		((y - EPOCH_YEAR) % DAYSPERWEEK) *
1587 		(DAYSPERNYEAR % DAYSPERWEEK) +
1588 		leaps_thru_end_of(y - 1) -
1589 		leaps_thru_end_of(EPOCH_YEAR - 1) +
1590 		idays;
1591 	tmp->tm_wday %= DAYSPERWEEK;
1592 	if (tmp->tm_wday < 0)
1593 		tmp->tm_wday += DAYSPERWEEK;
1594 	tmp->tm_hour = (int) (rem / SECSPERHOUR);
1595 	rem %= SECSPERHOUR;
1596 	tmp->tm_min = (int) (rem / SECSPERMIN);
1597 	/*
1598 	** A positive leap second requires a special
1599 	** representation. This uses "... ??:59:60" et seq.
1600 	*/
1601 	tmp->tm_sec = (int) (rem % SECSPERMIN) + hit;
1602 	ip = mon_lengths[isleap(y)];
1603 	for (tmp->tm_mon = 0; idays >= ip[tmp->tm_mon]; ++(tmp->tm_mon))
1604 		idays -= ip[tmp->tm_mon];
1605 	tmp->tm_mday = (int) (idays + 1);
1606 	tmp->tm_isdst = 0;
1607 #ifdef TM_GMTOFF
1608 	tmp->TM_GMTOFF = offset;
1609 #endif /* defined TM_GMTOFF */
1610 	return tmp;
1611 }
1612 
1613 char *
1614 ctime(timep)
1615 const time_t * const	timep;
1616 {
1617 /*
1618 ** Section 4.12.3.2 of X3.159-1989 requires that
1619 **	The ctime function converts the calendar time pointed to by timer
1620 **	to local time in the form of a string. It is equivalent to
1621 **		asctime(localtime(timer))
1622 */
1623 	return asctime(localtime(timep));
1624 }
1625 
1626 char *
1627 ctime_r(timep, buf)
1628 const time_t * const	timep;
1629 char *			buf;
1630 {
1631 	struct tm	mytm;
1632 
1633 	return asctime_r(localtime_r(timep, &mytm), buf);
1634 }
1635 
1636 /*
1637 ** Adapted from code provided by Robert Elz, who writes:
1638 **	The "best" way to do mktime I think is based on an idea of Bob
1639 **	Kridle's (so its said...) from a long time ago.
1640 **	It does a binary search of the time_t space. Since time_t's are
1641 **	just 32 bits, its a max of 32 iterations (even at 64 bits it
1642 **	would still be very reasonable).
1643 */
1644 
1645 #ifndef WRONG
1646 #define WRONG	(-1)
1647 #endif /* !defined WRONG */
1648 
1649 /*
1650 ** Normalize logic courtesy Paul Eggert.
1651 */
1652 
1653 static int
1654 increment_overflow(ip, j)
1655 int * const	ip;
1656 int		j;
1657 {
1658 	register int const	i = *ip;
1659 
1660 	/*
1661 	** If i >= 0 there can only be overflow if i + j > INT_MAX
1662 	** or if j > INT_MAX - i; given i >= 0, INT_MAX - i cannot overflow.
1663 	** If i < 0 there can only be overflow if i + j < INT_MIN
1664 	** or if j < INT_MIN - i; given i < 0, INT_MIN - i cannot overflow.
1665 	*/
1666 	if ((i >= 0) ? (j > INT_MAX - i) : (j < INT_MIN - i))
1667 		return TRUE;
1668 	*ip += j;
1669 	return FALSE;
1670 }
1671 
1672 static int
1673 long_increment_overflow(lp, m)
1674 long * const	lp;
1675 int const	m;
1676 {
1677 	register long const	l = *lp;
1678 
1679 	if ((l >= 0) ? (m > LONG_MAX - l) : (m < LONG_MIN - l))
1680 		return TRUE;
1681 	*lp += m;
1682 	return FALSE;
1683 }
1684 
1685 static int
1686 normalize_overflow(tensptr, unitsptr, base)
1687 int * const	tensptr;
1688 int * const	unitsptr;
1689 const int	base;
1690 {
1691 	register int	tensdelta;
1692 
1693 	tensdelta = (*unitsptr >= 0) ?
1694 		(*unitsptr / base) :
1695 		(-1 - (-1 - *unitsptr) / base);
1696 	*unitsptr -= tensdelta * base;
1697 	return increment_overflow(tensptr, tensdelta);
1698 }
1699 
1700 static int
1701 long_normalize_overflow(tensptr, unitsptr, base)
1702 long * const	tensptr;
1703 int * const	unitsptr;
1704 const int	base;
1705 {
1706 	register int	tensdelta;
1707 
1708 	tensdelta = (*unitsptr >= 0) ?
1709 		(*unitsptr / base) :
1710 		(-1 - (-1 - *unitsptr) / base);
1711 	*unitsptr -= tensdelta * base;
1712 	return long_increment_overflow(tensptr, tensdelta);
1713 }
1714 
1715 static int
1716 tmcomp(atmp, btmp)
1717 register const struct tm * const atmp;
1718 register const struct tm * const btmp;
1719 {
1720 	register int	result;
1721 
1722 	if ((result = (atmp->tm_year - btmp->tm_year)) == 0 &&
1723 		(result = (atmp->tm_mon - btmp->tm_mon)) == 0 &&
1724 		(result = (atmp->tm_mday - btmp->tm_mday)) == 0 &&
1725 		(result = (atmp->tm_hour - btmp->tm_hour)) == 0 &&
1726 		(result = (atmp->tm_min - btmp->tm_min)) == 0)
1727 			result = atmp->tm_sec - btmp->tm_sec;
1728 	return result;
1729 }
1730 
1731 static time_t
1732 time2sub(tmp, funcp, offset, okayp, do_norm_secs)
1733 struct tm * const	tmp;
1734 struct tm * (* const	funcp)(const time_t*, long, struct tm*);
1735 const long		offset;
1736 int * const		okayp;
1737 const int		do_norm_secs;
1738 {
1739 	register const struct state *	sp;
1740 	register int			dir;
1741 	register int			i, j;
1742 	register int			saved_seconds;
1743 	register long			li;
1744 	register time_t			lo;
1745 	register time_t			hi;
1746 	long				y;
1747 	time_t				newt;
1748 	time_t				t;
1749 	struct tm			yourtm, mytm;
1750 
1751 	*okayp = FALSE;
1752 	yourtm = *tmp;
1753 	if (do_norm_secs) {
1754 		if (normalize_overflow(&yourtm.tm_min, &yourtm.tm_sec,
1755 			SECSPERMIN))
1756 				return WRONG;
1757 	}
1758 	if (normalize_overflow(&yourtm.tm_hour, &yourtm.tm_min, MINSPERHOUR))
1759 		return WRONG;
1760 	if (normalize_overflow(&yourtm.tm_mday, &yourtm.tm_hour, HOURSPERDAY))
1761 		return WRONG;
1762 	y = yourtm.tm_year;
1763 	if (long_normalize_overflow(&y, &yourtm.tm_mon, MONSPERYEAR))
1764 		return WRONG;
1765 	/*
1766 	** Turn y into an actual year number for now.
1767 	** It is converted back to an offset from TM_YEAR_BASE later.
1768 	*/
1769 	if (long_increment_overflow(&y, TM_YEAR_BASE))
1770 		return WRONG;
1771 	while (yourtm.tm_mday <= 0) {
1772 		if (long_increment_overflow(&y, -1))
1773 			return WRONG;
1774 		li = y + (1 < yourtm.tm_mon);
1775 		yourtm.tm_mday += year_lengths[isleap(li)];
1776 	}
1777 	while (yourtm.tm_mday > DAYSPERLYEAR) {
1778 		li = y + (1 < yourtm.tm_mon);
1779 		yourtm.tm_mday -= year_lengths[isleap(li)];
1780 		if (long_increment_overflow(&y, 1))
1781 			return WRONG;
1782 	}
1783 	for ( ; ; ) {
1784 		i = mon_lengths[isleap(y)][yourtm.tm_mon];
1785 		if (yourtm.tm_mday <= i)
1786 			break;
1787 		yourtm.tm_mday -= i;
1788 		if (++yourtm.tm_mon >= MONSPERYEAR) {
1789 			yourtm.tm_mon = 0;
1790 			if (long_increment_overflow(&y, 1))
1791 				return WRONG;
1792 		}
1793 	}
1794 	if (long_increment_overflow(&y, -TM_YEAR_BASE))
1795 		return WRONG;
1796 	yourtm.tm_year = y;
1797 	if (yourtm.tm_year != y)
1798 		return WRONG;
1799 	if (yourtm.tm_sec >= 0 && yourtm.tm_sec < SECSPERMIN)
1800 		saved_seconds = 0;
1801 	else if (y + TM_YEAR_BASE < EPOCH_YEAR) {
1802 		/*
1803 		** We can't set tm_sec to 0, because that might push the
1804 		** time below the minimum representable time.
1805 		** Set tm_sec to 59 instead.
1806 		** This assumes that the minimum representable time is
1807 		** not in the same minute that a leap second was deleted from,
1808 		** which is a safer assumption than using 58 would be.
1809 		*/
1810 		if (increment_overflow(&yourtm.tm_sec, 1 - SECSPERMIN))
1811 			return WRONG;
1812 		saved_seconds = yourtm.tm_sec;
1813 		yourtm.tm_sec = SECSPERMIN - 1;
1814 	} else {
1815 		saved_seconds = yourtm.tm_sec;
1816 		yourtm.tm_sec = 0;
1817 	}
1818 	/*
1819 	** Do a binary search (this works whatever time_t's type is).
1820 	*/
1821 	if (!TYPE_SIGNED(time_t)) {
1822 		lo = 0;
1823 		hi = lo - 1;
1824 	} else if (!TYPE_INTEGRAL(time_t)) {
1825 		if (sizeof(time_t) > sizeof(float))
1826 			hi = (time_t) DBL_MAX;
1827 		else	hi = (time_t) FLT_MAX;
1828 		lo = -hi;
1829 	} else {
1830 		lo = 1;
1831 		for (i = 0; i < (int) TYPE_BIT(time_t) - 1; ++i)
1832 			lo *= 2;
1833 		hi = -(lo + 1);
1834 	}
1835 	for ( ; ; ) {
1836 		t = lo / 2 + hi / 2;
1837 		if (t < lo)
1838 			t = lo;
1839 		else if (t > hi)
1840 			t = hi;
1841 		if ((*funcp)(&t, offset, &mytm) == NULL) {
1842 			/*
1843 			** Assume that t is too extreme to be represented in
1844 			** a struct tm; arrange things so that it is less
1845 			** extreme on the next pass.
1846 			*/
1847 			dir = (t > 0) ? 1 : -1;
1848 		} else	dir = tmcomp(&mytm, &yourtm);
1849 		if (dir != 0) {
1850 			if (t == lo) {
1851 				++t;
1852 				if (t <= lo)
1853 					return WRONG;
1854 				++lo;
1855 			} else if (t == hi) {
1856 				--t;
1857 				if (t >= hi)
1858 					return WRONG;
1859 				--hi;
1860 			}
1861 			if (lo > hi)
1862 				return WRONG;
1863 			if (dir > 0)
1864 				hi = t;
1865 			else	lo = t;
1866 			continue;
1867 		}
1868 		if (yourtm.tm_isdst < 0 || mytm.tm_isdst == yourtm.tm_isdst)
1869 			break;
1870 		/*
1871 		** Right time, wrong type.
1872 		** Hunt for right time, right type.
1873 		** It's okay to guess wrong since the guess
1874 		** gets checked.
1875 		*/
1876 		sp = (const struct state *)
1877 			((funcp == localsub) ? lclptr : gmtptr);
1878 #ifdef ALL_STATE
1879 		if (sp == NULL)
1880 			return WRONG;
1881 #endif /* defined ALL_STATE */
1882 		for (i = sp->typecnt - 1; i >= 0; --i) {
1883 			if (sp->ttis[i].tt_isdst != yourtm.tm_isdst)
1884 				continue;
1885 			for (j = sp->typecnt - 1; j >= 0; --j) {
1886 				if (sp->ttis[j].tt_isdst == yourtm.tm_isdst)
1887 					continue;
1888 				newt = t + sp->ttis[j].tt_gmtoff -
1889 					sp->ttis[i].tt_gmtoff;
1890 				if ((*funcp)(&newt, offset, &mytm) == NULL)
1891 					continue;
1892 				if (tmcomp(&mytm, &yourtm) != 0)
1893 					continue;
1894 				if (mytm.tm_isdst != yourtm.tm_isdst)
1895 					continue;
1896 				/*
1897 				** We have a match.
1898 				*/
1899 				t = newt;
1900 				goto label;
1901 			}
1902 		}
1903 		return WRONG;
1904 	}
1905 label:
1906 	newt = t + saved_seconds;
1907 	if ((newt < t) != (saved_seconds < 0))
1908 		return WRONG;
1909 	t = newt;
1910 	if ((*funcp)(&t, offset, tmp))
1911 		*okayp = TRUE;
1912 	return t;
1913 }
1914 
1915 static time_t
1916 time2(tmp, funcp, offset, okayp)
1917 struct tm * const	tmp;
1918 struct tm * (* const	funcp)(const time_t*, long, struct tm*);
1919 const long		offset;
1920 int * const		okayp;
1921 {
1922 	time_t	t;
1923 
1924 	/*
1925 	** First try without normalization of seconds
1926 	** (in case tm_sec contains a value associated with a leap second).
1927 	** If that fails, try with normalization of seconds.
1928 	*/
1929 	t = time2sub(tmp, funcp, offset, okayp, FALSE);
1930 	return *okayp ? t : time2sub(tmp, funcp, offset, okayp, TRUE);
1931 }
1932 
1933 static time_t
1934 time1(tmp, funcp, offset)
1935 struct tm * const	tmp;
1936 struct tm * (* const	funcp)(const time_t *, long, struct tm *);
1937 const long		offset;
1938 {
1939 	register time_t			t;
1940 	register const struct state *	sp;
1941 	register int			samei, otheri;
1942 	register int			sameind, otherind;
1943 	register int			i;
1944 	register int			nseen;
1945 	int				seen[TZ_MAX_TYPES];
1946 	int				types[TZ_MAX_TYPES];
1947 	int				okay;
1948 
1949 	if (tmp == NULL) {
1950 		errno = EINVAL;
1951 		return WRONG;
1952 	}
1953 	if (tmp->tm_isdst > 1)
1954 		tmp->tm_isdst = 1;
1955 	t = time2(tmp, funcp, offset, &okay);
1956 #ifdef PCTS
1957 	/*
1958 	** PCTS code courtesy Grant Sullivan.
1959 	*/
1960 	if (okay)
1961 		return t;
1962 	if (tmp->tm_isdst < 0)
1963 		tmp->tm_isdst = 0;	/* reset to std and try again */
1964 #endif /* defined PCTS */
1965 #ifndef PCTS
1966 	if (okay || tmp->tm_isdst < 0)
1967 		return t;
1968 #endif /* !defined PCTS */
1969 	/*
1970 	** We're supposed to assume that somebody took a time of one type
1971 	** and did some math on it that yielded a "struct tm" that's bad.
1972 	** We try to divine the type they started from and adjust to the
1973 	** type they need.
1974 	*/
1975 	sp = (const struct state *) ((funcp == localsub) ?  lclptr : gmtptr);
1976 #ifdef ALL_STATE
1977 	if (sp == NULL)
1978 		return WRONG;
1979 #endif /* defined ALL_STATE */
1980 	for (i = 0; i < sp->typecnt; ++i)
1981 		seen[i] = FALSE;
1982 	nseen = 0;
1983 	for (i = sp->timecnt - 1; i >= 0; --i)
1984 		if (!seen[sp->types[i]]) {
1985 			seen[sp->types[i]] = TRUE;
1986 			types[nseen++] = sp->types[i];
1987 		}
1988 	for (sameind = 0; sameind < nseen; ++sameind) {
1989 		samei = types[sameind];
1990 		if (sp->ttis[samei].tt_isdst != tmp->tm_isdst)
1991 			continue;
1992 		for (otherind = 0; otherind < nseen; ++otherind) {
1993 			otheri = types[otherind];
1994 			if (sp->ttis[otheri].tt_isdst == tmp->tm_isdst)
1995 				continue;
1996 			tmp->tm_sec += sp->ttis[otheri].tt_gmtoff -
1997 					sp->ttis[samei].tt_gmtoff;
1998 			tmp->tm_isdst = !tmp->tm_isdst;
1999 			t = time2(tmp, funcp, offset, &okay);
2000 			if (okay)
2001 				return t;
2002 			tmp->tm_sec -= sp->ttis[otheri].tt_gmtoff -
2003 					sp->ttis[samei].tt_gmtoff;
2004 			tmp->tm_isdst = !tmp->tm_isdst;
2005 		}
2006 	}
2007 	return WRONG;
2008 }
2009 
2010 time_t
2011 mktime(tmp)
2012 struct tm * const	tmp;
2013 {
2014 	time_t ret;
2015 
2016 	_THREAD_PRIVATE_MUTEX_LOCK(lcl);
2017 	tzset_basic();
2018 	ret = time1(tmp, localsub, 0L);
2019 	_THREAD_PRIVATE_MUTEX_UNLOCK(lcl);
2020 	return ret;
2021 }
2022 
2023 #ifdef STD_INSPIRED
2024 
2025 time_t
2026 timelocal(tmp)
2027 struct tm * const	tmp;
2028 {
2029 	if (tmp != NULL)
2030 		tmp->tm_isdst = -1;	/* in case it wasn't initialized */
2031 	return mktime(tmp);
2032 }
2033 
2034 time_t
2035 timegm(tmp)
2036 struct tm * const	tmp;
2037 {
2038 	if (tmp != NULL)
2039 		tmp->tm_isdst = 0;
2040 	return time1(tmp, gmtsub, 0L);
2041 }
2042 
2043 time_t
2044 timeoff(tmp, offset)
2045 struct tm * const	tmp;
2046 const long		offset;
2047 {
2048 	if (tmp != NULL)
2049 		tmp->tm_isdst = 0;
2050 	return time1(tmp, gmtsub, offset);
2051 }
2052 
2053 #endif /* defined STD_INSPIRED */
2054 
2055 #ifdef CMUCS
2056 
2057 /*
2058 ** The following is supplied for compatibility with
2059 ** previous versions of the CMUCS runtime library.
2060 */
2061 
2062 long
2063 gtime(tmp)
2064 struct tm * const	tmp;
2065 {
2066 	const time_t	t = mktime(tmp);
2067 
2068 	if (t == WRONG)
2069 		return -1;
2070 	return t;
2071 }
2072 
2073 #endif /* defined CMUCS */
2074 
2075 /*
2076 ** XXX--is the below the right way to conditionalize??
2077 */
2078 
2079 #ifdef STD_INSPIRED
2080 
2081 /*
2082 ** IEEE Std 1003.1-1988 (POSIX) legislates that 536457599
2083 ** shall correspond to "Wed Dec 31 23:59:59 UTC 1986", which
2084 ** is not the case if we are accounting for leap seconds.
2085 ** So, we provide the following conversion routines for use
2086 ** when exchanging timestamps with POSIX conforming systems.
2087 */
2088 
2089 static long
2090 leapcorr(timep)
2091 time_t *	timep;
2092 {
2093 	register struct state *		sp;
2094 	register struct lsinfo *	lp;
2095 	register int			i;
2096 
2097 	sp = lclptr;
2098 	i = sp->leapcnt;
2099 	while (--i >= 0) {
2100 		lp = &sp->lsis[i];
2101 		if (*timep >= lp->ls_trans)
2102 			return lp->ls_corr;
2103 	}
2104 	return 0;
2105 }
2106 
2107 time_t
2108 time2posix(t)
2109 time_t	t;
2110 {
2111 	tzset();
2112 	return t - leapcorr(&t);
2113 }
2114 
2115 time_t
2116 posix2time(t)
2117 time_t	t;
2118 {
2119 	time_t	x;
2120 	time_t	y;
2121 
2122 	tzset();
2123 	/*
2124 	** For a positive leap second hit, the result
2125 	** is not unique. For a negative leap second
2126 	** hit, the corresponding time doesn't exist,
2127 	** so we return an adjacent second.
2128 	*/
2129 	x = t + leapcorr(&t);
2130 	y = x - leapcorr(&x);
2131 	if (y < t) {
2132 		do {
2133 			x++;
2134 			y = x - leapcorr(&x);
2135 		} while (y < t);
2136 		if (t != y)
2137 			return x - 1;
2138 	} else if (y > t) {
2139 		do {
2140 			--x;
2141 			y = x - leapcorr(&x);
2142 		} while (y > t);
2143 		if (t != y)
2144 			return x + 1;
2145 	}
2146 	return x;
2147 }
2148 
2149 #endif /* defined STD_INSPIRED */
2150