xref: /NextBSD/contrib/tzcode/stdtime/localtime.c (revision 84d351007654069f9643c8e4b4802a7f5f08ee42)
1 /*
2 ** This file is in the public domain, so clarified as of
3 ** 1996-06-05 by Arthur David Olson.
4 */
5 
6 #include <sys/cdefs.h>
7 #ifndef lint
8 #ifndef NOID
9 static char	elsieid[] __unused = "@(#)localtime.c	8.14";
10 #endif /* !defined NOID */
11 #endif /* !defined lint */
12 __FBSDID("$FreeBSD$");
13 
14 /*
15 ** Leap second handling from Bradley White.
16 ** POSIX-style TZ environment variable handling from Guy Harris.
17 */
18 
19 /*LINTLIBRARY*/
20 
21 #include "namespace.h"
22 #include <sys/types.h>
23 #include <sys/stat.h>
24 #include <errno.h>
25 #include <fcntl.h>
26 #include <pthread.h>
27 #include "private.h"
28 #include "un-namespace.h"
29 
30 #include "tzfile.h"
31 #include "float.h"	/* for FLT_MAX and DBL_MAX */
32 
33 #ifndef TZ_ABBR_MAX_LEN
34 #define TZ_ABBR_MAX_LEN	16
35 #endif /* !defined TZ_ABBR_MAX_LEN */
36 
37 #ifndef TZ_ABBR_CHAR_SET
38 #define TZ_ABBR_CHAR_SET \
39 	"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789 :+-._"
40 #endif /* !defined TZ_ABBR_CHAR_SET */
41 
42 #ifndef TZ_ABBR_ERR_CHAR
43 #define TZ_ABBR_ERR_CHAR	'_'
44 #endif /* !defined TZ_ABBR_ERR_CHAR */
45 
46 #include "libc_private.h"
47 
48 #define	_MUTEX_LOCK(x)		if (__isthreaded) _pthread_mutex_lock(x)
49 #define	_MUTEX_UNLOCK(x)	if (__isthreaded) _pthread_mutex_unlock(x)
50 
51 #define _RWLOCK_RDLOCK(x)						\
52 		do {							\
53 			if (__isthreaded) _pthread_rwlock_rdlock(x);	\
54 		} while (0)
55 
56 #define _RWLOCK_WRLOCK(x)						\
57 		do {							\
58 			if (__isthreaded) _pthread_rwlock_wrlock(x);	\
59 		} while (0)
60 
61 #define _RWLOCK_UNLOCK(x)						\
62 		do {							\
63 			if (__isthreaded) _pthread_rwlock_unlock(x);	\
64 		} while (0)
65 
66 /*
67 ** SunOS 4.1.1 headers lack O_BINARY.
68 */
69 
70 #ifdef O_BINARY
71 #define OPEN_MODE	(O_RDONLY | O_BINARY)
72 #endif /* defined O_BINARY */
73 #ifndef O_BINARY
74 #define OPEN_MODE	O_RDONLY
75 #endif /* !defined O_BINARY */
76 
77 #ifndef WILDABBR
78 /*
79 ** Someone might make incorrect use of a time zone abbreviation:
80 **	1.	They might reference tzname[0] before calling tzset (explicitly
81 **		or implicitly).
82 **	2.	They might reference tzname[1] before calling tzset (explicitly
83 **		or implicitly).
84 **	3.	They might reference tzname[1] after setting to a time zone
85 **		in which Daylight Saving Time is never observed.
86 **	4.	They might reference tzname[0] after setting to a time zone
87 **		in which Standard Time is never observed.
88 **	5.	They might reference tm.TM_ZONE after calling offtime.
89 ** What's best to do in the above cases is open to debate;
90 ** for now, we just set things up so that in any of the five cases
91 ** WILDABBR is used. Another possibility: initialize tzname[0] to the
92 ** string "tzname[0] used before set", and similarly for the other cases.
93 ** And another: initialize tzname[0] to "ERA", with an explanation in the
94 ** manual page of what this "time zone abbreviation" means (doing this so
95 ** that tzname[0] has the "normal" length of three characters).
96 */
97 #define WILDABBR	"   "
98 #endif /* !defined WILDABBR */
99 
100 static char		wildabbr[] = WILDABBR;
101 
102 /*
103  * In June 2004 it was decided UTC was a more appropriate default time
104  * zone than GMT.
105  */
106 
107 static const char	gmt[] = "UTC";
108 
109 /*
110 ** The DST rules to use if TZ has no rules and we can't load TZDEFRULES.
111 ** We default to US rules as of 1999-08-17.
112 ** POSIX 1003.1 section 8.1.1 says that the default DST rules are
113 ** implementation dependent; for historical reasons, US rules are a
114 ** common default.
115 */
116 #ifndef TZDEFRULESTRING
117 #define TZDEFRULESTRING ",M4.1.0,M10.5.0"
118 #endif /* !defined TZDEFDST */
119 
120 struct ttinfo {				/* time type information */
121 	long		tt_gmtoff;	/* UTC offset in seconds */
122 	int		tt_isdst;	/* used to set tm_isdst */
123 	int		tt_abbrind;	/* abbreviation list index */
124 	int		tt_ttisstd;	/* TRUE if transition is std time */
125 	int		tt_ttisgmt;	/* TRUE if transition is UTC */
126 };
127 
128 struct lsinfo {				/* leap second information */
129 	time_t		ls_trans;	/* transition time */
130 	long		ls_corr;	/* correction to apply */
131 };
132 
133 #define BIGGEST(a, b)	(((a) > (b)) ? (a) : (b))
134 
135 #ifdef TZNAME_MAX
136 #define MY_TZNAME_MAX	TZNAME_MAX
137 #endif /* defined TZNAME_MAX */
138 #ifndef TZNAME_MAX
139 #define MY_TZNAME_MAX	255
140 #endif /* !defined TZNAME_MAX */
141 
142 struct state {
143 	int		leapcnt;
144 	int		timecnt;
145 	int		typecnt;
146 	int		charcnt;
147 	int		goback;
148 	int		goahead;
149 	time_t		ats[TZ_MAX_TIMES];
150 	unsigned char	types[TZ_MAX_TIMES];
151 	struct ttinfo	ttis[TZ_MAX_TYPES];
152 	char		chars[BIGGEST(BIGGEST(TZ_MAX_CHARS + 1, sizeof gmt),
153 				(2 * (MY_TZNAME_MAX + 1)))];
154 	struct lsinfo	lsis[TZ_MAX_LEAPS];
155 };
156 
157 struct rule {
158 	int		r_type;		/* type of rule--see below */
159 	int		r_day;		/* day number of rule */
160 	int		r_week;		/* week number of rule */
161 	int		r_mon;		/* month number of rule */
162 	long		r_time;		/* transition time of rule */
163 };
164 
165 #define JULIAN_DAY		0	/* Jn - Julian day */
166 #define DAY_OF_YEAR		1	/* n - day of year */
167 #define MONTH_NTH_DAY_OF_WEEK	2	/* Mm.n.d - month, week, day of week */
168 
169 /*
170 ** Prototypes for static functions.
171 */
172 
173 static long		detzcode(const char * codep);
174 static time_t		detzcode64(const char * codep);
175 static int		differ_by_repeat(time_t t1, time_t t0);
176 static const char *	getzname(const char * strp) ATTRIBUTE_PURE;
177 static const char *	getqzname(const char * strp, const int delim)
178   ATTRIBUTE_PURE;
179 static const char *	getnum(const char * strp, int * nump, int min,
180 				int max);
181 static const char *	getsecs(const char * strp, long * secsp);
182 static const char *	getoffset(const char * strp, long * offsetp);
183 static const char *	getrule(const char * strp, struct rule * rulep);
184 static void		gmtload(struct state * sp);
185 static struct tm *	gmtsub(const time_t * timep, long offset,
186 				struct tm * tmp);
187 static struct tm *	localsub(const time_t * timep, long offset,
188 				struct tm * tmp);
189 static int		increment_overflow(int * number, int delta);
190 static int		leaps_thru_end_of(int y) ATTRIBUTE_PURE;
191 static int		long_increment_overflow(long * number, int delta);
192 static int		long_normalize_overflow(long * tensptr,
193 				int * unitsptr, int base);
194 static int		normalize_overflow(int * tensptr, int * unitsptr,
195 				int base);
196 static void		settzname(void);
197 static time_t		time1(struct tm * tmp,
198 				struct tm * (*funcp)(const time_t *,
199 				long, struct tm *),
200 				long offset);
201 static time_t		time2(struct tm *tmp,
202 				struct tm * (*funcp)(const time_t *,
203 				long, struct tm*),
204 				long offset, int * okayp);
205 static time_t		time2sub(struct tm *tmp,
206 				struct tm * (*funcp)(const time_t *,
207 				long, struct tm*),
208 				long offset, int * okayp, int do_norm_secs);
209 static struct tm *	timesub(const time_t * timep, long offset,
210 				const struct state * sp, struct tm * tmp);
211 static int		tmcomp(const struct tm * atmp,
212 				const struct tm * btmp);
213 static time_t		transtime(time_t janfirst, int year,
214 				  const struct rule * rulep, long offset)
215   ATTRIBUTE_PURE;
216 static int		typesequiv(const struct state * sp, int a, int b);
217 static int		tzload(const char * name, struct state * sp,
218 				int doextend);
219 static int		tzparse(const char * name, struct state * sp,
220 				int lastditch);
221 
222 #ifdef ALL_STATE
223 static struct state *	lclptr;
224 static struct state *	gmtptr;
225 #endif /* defined ALL_STATE */
226 
227 #ifndef ALL_STATE
228 static struct state	lclmem;
229 static struct state	gmtmem;
230 #define lclptr		(&lclmem)
231 #define gmtptr		(&gmtmem)
232 #endif /* State Farm */
233 
234 #ifndef TZ_STRLEN_MAX
235 #define TZ_STRLEN_MAX 255
236 #endif /* !defined TZ_STRLEN_MAX */
237 
238 static char		lcl_TZname[TZ_STRLEN_MAX + 1];
239 static int		lcl_is_set;
240 static pthread_once_t	gmt_once = PTHREAD_ONCE_INIT;
241 static pthread_rwlock_t	lcl_rwlock = PTHREAD_RWLOCK_INITIALIZER;
242 static pthread_once_t	gmtime_once = PTHREAD_ONCE_INIT;
243 static pthread_key_t	gmtime_key;
244 static int		gmtime_key_error;
245 static pthread_once_t	localtime_once = PTHREAD_ONCE_INIT;
246 static pthread_key_t	localtime_key;
247 static int		localtime_key_error;
248 
249 char *			tzname[2] = {
250 	wildabbr,
251 	wildabbr
252 };
253 
254 /*
255 ** Section 4.12.3 of X3.159-1989 requires that
256 **	Except for the strftime function, these functions [asctime,
257 **	ctime, gmtime, localtime] return values in one of two static
258 **	objects: a broken-down time structure and an array of char.
259 ** Thanks to Paul Eggert for noting this.
260 */
261 
262 static struct tm	tm;
263 
264 #ifdef USG_COMPAT
265 time_t			timezone = 0;
266 int			daylight = 0;
267 #endif /* defined USG_COMPAT */
268 
269 #ifdef ALTZONE
270 time_t			altzone = 0;
271 #endif /* defined ALTZONE */
272 
273 static long
detzcode(const char * const codep)274 detzcode(const char *const codep)
275 {
276 	long	result;
277 	int	i;
278 
279 	result = (codep[0] & 0x80) ? ~0L : 0;
280 	for (i = 0; i < 4; ++i)
281 		result = (result << 8) | (codep[i] & 0xff);
282 	return result;
283 }
284 
285 static time_t
detzcode64(const char * const codep)286 detzcode64(const char *const codep)
287 {
288 	register time_t	result;
289 	register int	i;
290 
291 	result = (codep[0] & 0x80) ?  (~(int_fast64_t) 0) : 0;
292 	for (i = 0; i < 8; ++i)
293 		result = result * 256 + (codep[i] & 0xff);
294 	return result;
295 }
296 
297 static void
settzname(void)298 settzname(void)
299 {
300 	struct state * 	sp = lclptr;
301 	int			i;
302 
303 	tzname[0] = wildabbr;
304 	tzname[1] = wildabbr;
305 #ifdef USG_COMPAT
306 	daylight = 0;
307 	timezone = 0;
308 #endif /* defined USG_COMPAT */
309 #ifdef ALTZONE
310 	altzone = 0;
311 #endif /* defined ALTZONE */
312 #ifdef ALL_STATE
313 	if (sp == NULL) {
314 		tzname[0] = tzname[1] = gmt;
315 		return;
316 	}
317 #endif /* defined ALL_STATE */
318 	/*
319 	** And to get the latest zone names into tzname. . .
320 	*/
321 	for (i = 0; i < sp->typecnt; ++i) {
322 		const struct ttinfo * const ttisp = &sp->ttis[sp->types[i]];
323 
324 		tzname[ttisp->tt_isdst] =
325 			&sp->chars[ttisp->tt_abbrind];
326 #ifdef USG_COMPAT
327 		if (ttisp->tt_isdst)
328 			daylight = 1;
329 		if (!ttisp->tt_isdst)
330 			timezone = -(ttisp->tt_gmtoff);
331 #endif /* defined USG_COMPAT */
332 #ifdef ALTZONE
333 		if (ttisp->tt_isdst)
334 			altzone = -(ttisp->tt_gmtoff);
335 #endif /* defined ALTZONE */
336 	}
337 	/*
338 	** Finally, scrub the abbreviations.
339 	** First, replace bogus characters.
340 	*/
341 	for (i = 0; i < sp->charcnt; ++i)
342 		if (strchr(TZ_ABBR_CHAR_SET, sp->chars[i]) == NULL)
343 			sp->chars[i] = TZ_ABBR_ERR_CHAR;
344 	/*
345 	** Second, truncate long abbreviations.
346 	*/
347 	for (i = 0; i < sp->typecnt; ++i) {
348 		register const struct ttinfo * const	ttisp = &sp->ttis[i];
349 		register char *				cp = &sp->chars[ttisp->tt_abbrind];
350 
351 		if (strlen(cp) > TZ_ABBR_MAX_LEN &&
352 			strcmp(cp, GRANDPARENTED) != 0)
353 				*(cp + TZ_ABBR_MAX_LEN) = '\0';
354 	}
355 }
356 
357 static int
differ_by_repeat(const time_t t1,const time_t t0)358 differ_by_repeat(const time_t t1, const time_t t0)
359 {
360 	int_fast64_t _t0 = t0;
361 	int_fast64_t _t1 = t1;
362 
363 	if (TYPE_INTEGRAL(time_t) &&
364 		TYPE_BIT(time_t) - TYPE_SIGNED(time_t) < SECSPERREPEAT_BITS)
365 			return 0;
366 	//turn ((int_fast64_t)(t1 - t0) == SECSPERREPEAT);
367 	return _t1 - _t0 == SECSPERREPEAT;
368 }
369 
370 static int
tzload(name,sp,doextend)371 tzload(name, sp, doextend)
372 const char *		name;
373 struct state * const	sp;
374 register const int	doextend;
375 {
376 	const char *	p;
377 	int		i;
378 	int		fid;
379 	int		stored;
380 	int		nread;
381 	int		res;
382 	union {
383 		struct tzhead	tzhead;
384 		char		buf[2 * sizeof(struct tzhead) +
385 					2 * sizeof *sp +
386 					4 * TZ_MAX_TIMES];
387 	} *u;
388 
389 	u = NULL;
390 	res = -1;
391 	sp->goback = sp->goahead = FALSE;
392 
393 	/* XXX The following is from OpenBSD, and I'm not sure it is correct */
394 	if (name != NULL && issetugid() != 0)
395 		if ((name[0] == ':' && name[1] == '/') ||
396 		    name[0] == '/' || strchr(name, '.'))
397 			name = NULL;
398 	if (name == NULL && (name = TZDEFAULT) == NULL)
399 		return -1;
400 	{
401 		int	doaccess;
402 		struct stat	stab;
403 		/*
404 		** Section 4.9.1 of the C standard says that
405 		** "FILENAME_MAX expands to an integral constant expression
406 		** that is the size needed for an array of char large enough
407 		** to hold the longest file name string that the implementation
408 		** guarantees can be opened."
409 		*/
410 		char		*fullname;
411 
412 		fullname = malloc(FILENAME_MAX + 1);
413 		if (fullname == NULL)
414 			goto out;
415 
416 		if (name[0] == ':')
417 			++name;
418 		doaccess = name[0] == '/';
419 		if (!doaccess) {
420 			if ((p = TZDIR) == NULL) {
421 				free(fullname);
422 				return -1;
423 			}
424 			if (strlen(p) + 1 + strlen(name) >= FILENAME_MAX) {
425 				free(fullname);
426 				return -1;
427 			}
428 			(void) strcpy(fullname, p);
429 			(void) strcat(fullname, "/");
430 			(void) strcat(fullname, name);
431 			/*
432 			** Set doaccess if '.' (as in "../") shows up in name.
433 			*/
434 			if (strchr(name, '.') != NULL)
435 				doaccess = TRUE;
436 			name = fullname;
437 		}
438 		if (doaccess && access(name, R_OK) != 0) {
439 			free(fullname);
440 		     	return -1;
441 		}
442 		if ((fid = _open(name, OPEN_MODE)) == -1) {
443 			free(fullname);
444 			return -1;
445 		}
446 		if ((_fstat(fid, &stab) < 0) || !S_ISREG(stab.st_mode)) {
447 			free(fullname);
448 			_close(fid);
449 			return -1;
450 		}
451 		free(fullname);
452 	}
453 	u = malloc(sizeof(*u));
454 	if (u == NULL)
455 		goto out;
456 	nread = _read(fid, u->buf, sizeof u->buf);
457 	if (_close(fid) < 0 || nread <= 0)
458 		goto out;
459 	for (stored = 4; stored <= 8; stored *= 2) {
460 		int		ttisstdcnt;
461 		int		ttisgmtcnt;
462 
463 		ttisstdcnt = (int) detzcode(u->tzhead.tzh_ttisstdcnt);
464 		ttisgmtcnt = (int) detzcode(u->tzhead.tzh_ttisgmtcnt);
465 		sp->leapcnt = (int) detzcode(u->tzhead.tzh_leapcnt);
466 		sp->timecnt = (int) detzcode(u->tzhead.tzh_timecnt);
467 		sp->typecnt = (int) detzcode(u->tzhead.tzh_typecnt);
468 		sp->charcnt = (int) detzcode(u->tzhead.tzh_charcnt);
469 		p = u->tzhead.tzh_charcnt + sizeof u->tzhead.tzh_charcnt;
470 		if (sp->leapcnt < 0 || sp->leapcnt > TZ_MAX_LEAPS ||
471 			sp->typecnt <= 0 || sp->typecnt > TZ_MAX_TYPES ||
472 			sp->timecnt < 0 || sp->timecnt > TZ_MAX_TIMES ||
473 			sp->charcnt < 0 || sp->charcnt > TZ_MAX_CHARS ||
474 			(ttisstdcnt != sp->typecnt && ttisstdcnt != 0) ||
475 			(ttisgmtcnt != sp->typecnt && ttisgmtcnt != 0))
476 				goto out;
477 		if (nread - (p - u->buf) <
478 			sp->timecnt * stored +		/* ats */
479 			sp->timecnt +			/* types */
480 			sp->typecnt * 6 +		/* ttinfos */
481 			sp->charcnt +			/* chars */
482 			sp->leapcnt * (stored + 4) +	/* lsinfos */
483 			ttisstdcnt +			/* ttisstds */
484 			ttisgmtcnt)			/* ttisgmts */
485 				goto out;
486 		for (i = 0; i < sp->timecnt; ++i) {
487 			sp->ats[i] = (stored == 4) ?
488 				detzcode(p) : detzcode64(p);
489 			p += stored;
490 		}
491 		for (i = 0; i < sp->timecnt; ++i) {
492 			sp->types[i] = (unsigned char) *p++;
493 			if (sp->types[i] >= sp->typecnt)
494 				goto out;
495 		}
496 		for (i = 0; i < sp->typecnt; ++i) {
497 			struct ttinfo *	ttisp;
498 
499 			ttisp = &sp->ttis[i];
500 			ttisp->tt_gmtoff = detzcode(p);
501 			p += 4;
502 			ttisp->tt_isdst = (unsigned char) *p++;
503 			if (ttisp->tt_isdst != 0 && ttisp->tt_isdst != 1)
504 				goto out;
505 			ttisp->tt_abbrind = (unsigned char) *p++;
506 			if (ttisp->tt_abbrind < 0 ||
507 				ttisp->tt_abbrind > sp->charcnt)
508 					goto out;
509 		}
510 		for (i = 0; i < sp->charcnt; ++i)
511 			sp->chars[i] = *p++;
512 		sp->chars[i] = '\0';	/* ensure '\0' at end */
513 		for (i = 0; i < sp->leapcnt; ++i) {
514 			struct lsinfo *	lsisp;
515 
516 			lsisp = &sp->lsis[i];
517 			lsisp->ls_trans = (stored == 4) ?
518 				detzcode(p) : detzcode64(p);
519 			p += stored;
520 			lsisp->ls_corr = detzcode(p);
521 			p += 4;
522 		}
523 		for (i = 0; i < sp->typecnt; ++i) {
524 			struct ttinfo *	ttisp;
525 
526 			ttisp = &sp->ttis[i];
527 			if (ttisstdcnt == 0)
528 				ttisp->tt_ttisstd = FALSE;
529 			else {
530 				ttisp->tt_ttisstd = *p++;
531 				if (ttisp->tt_ttisstd != TRUE &&
532 					ttisp->tt_ttisstd != FALSE)
533 						goto out;
534 			}
535 		}
536 		for (i = 0; i < sp->typecnt; ++i) {
537 			struct ttinfo *	ttisp;
538 
539 			ttisp = &sp->ttis[i];
540 			if (ttisgmtcnt == 0)
541 				ttisp->tt_ttisgmt = FALSE;
542 			else {
543 				ttisp->tt_ttisgmt = *p++;
544 				if (ttisp->tt_ttisgmt != TRUE &&
545 					ttisp->tt_ttisgmt != FALSE)
546 						goto out;
547 			}
548 		}
549 		/*
550 		** Out-of-sort ats should mean we're running on a
551 		** signed time_t system but using a data file with
552 		** unsigned values (or vice versa).
553 		*/
554 		for (i = 0; i < sp->timecnt - 2; ++i)
555 			if (sp->ats[i] > sp->ats[i + 1]) {
556 				++i;
557 				if (TYPE_SIGNED(time_t)) {
558 					/*
559 					** Ignore the end (easy).
560 					*/
561 					sp->timecnt = i;
562 				} else {
563 					/*
564 					** Ignore the beginning (harder).
565 					*/
566 					register int	j;
567 
568 					for (j = 0; j + i < sp->timecnt; ++j) {
569 						sp->ats[j] = sp->ats[j + i];
570 						sp->types[j] = sp->types[j + i];
571 					}
572 					sp->timecnt = j;
573 				}
574 				break;
575 			}
576 		/*
577 		** If this is an old file, we're done.
578 		*/
579 		if (u->tzhead.tzh_version[0] == '\0')
580 			break;
581 		nread -= p - u->buf;
582 		for (i = 0; i < nread; ++i)
583 			u->buf[i] = p[i];
584 		/*
585 		** If this is a narrow integer time_t system, we're done.
586 		*/
587 		if (stored >= (int) sizeof(time_t) && TYPE_INTEGRAL(time_t))
588 			break;
589 	}
590 	if (doextend && nread > 2 &&
591 		u->buf[0] == '\n' && u->buf[nread - 1] == '\n' &&
592 		sp->typecnt + 2 <= TZ_MAX_TYPES) {
593 			struct state	*ts;
594 			register int	result;
595 
596 			ts = malloc(sizeof(*ts));
597 			if (ts == NULL)
598 				goto out;
599 			u->buf[nread - 1] = '\0';
600 			result = tzparse(&u->buf[1], ts, FALSE);
601 			if (result == 0 && ts->typecnt == 2 &&
602 				sp->charcnt + ts->charcnt <= TZ_MAX_CHARS) {
603 					for (i = 0; i < 2; ++i)
604 						ts->ttis[i].tt_abbrind +=
605 							sp->charcnt;
606 					for (i = 0; i < ts->charcnt; ++i)
607 						sp->chars[sp->charcnt++] =
608 							ts->chars[i];
609 					i = 0;
610 					while (i < ts->timecnt &&
611 						ts->ats[i] <=
612 						sp->ats[sp->timecnt - 1])
613 							++i;
614 					while (i < ts->timecnt &&
615 					    sp->timecnt < TZ_MAX_TIMES) {
616 						sp->ats[sp->timecnt] =
617 							ts->ats[i];
618 						sp->types[sp->timecnt] =
619 							sp->typecnt +
620 							ts->types[i];
621 						++sp->timecnt;
622 						++i;
623 					}
624 					sp->ttis[sp->typecnt++] = ts->ttis[0];
625 					sp->ttis[sp->typecnt++] = ts->ttis[1];
626 			}
627 			free(ts);
628 	}
629 	if (sp->timecnt > 1) {
630 		for (i = 1; i < sp->timecnt; ++i)
631 			if (typesequiv(sp, sp->types[i], sp->types[0]) &&
632 				differ_by_repeat(sp->ats[i], sp->ats[0])) {
633 					sp->goback = TRUE;
634 					break;
635 				}
636 		for (i = sp->timecnt - 2; i >= 0; --i)
637 			if (typesequiv(sp, sp->types[sp->timecnt - 1],
638 				sp->types[i]) &&
639 				differ_by_repeat(sp->ats[sp->timecnt - 1],
640 				sp->ats[i])) {
641 					sp->goahead = TRUE;
642 					break;
643 		}
644 	}
645 	res = 0;
646 out:
647 	free(u);
648 	return (res);
649 }
650 
651 static int
typesequiv(sp,a,b)652 typesequiv(sp, a, b)
653 const struct state * const	sp;
654 const int			a;
655 const int			b;
656 {
657 	register int	result;
658 
659 	if (sp == NULL ||
660 		a < 0 || a >= sp->typecnt ||
661 		b < 0 || b >= sp->typecnt)
662 			result = FALSE;
663 	else {
664 		register const struct ttinfo *	ap = &sp->ttis[a];
665 		register const struct ttinfo *	bp = &sp->ttis[b];
666 		result = ap->tt_gmtoff == bp->tt_gmtoff &&
667 			ap->tt_isdst == bp->tt_isdst &&
668 			ap->tt_ttisstd == bp->tt_ttisstd &&
669 			ap->tt_ttisgmt == bp->tt_ttisgmt &&
670 			strcmp(&sp->chars[ap->tt_abbrind],
671 			&sp->chars[bp->tt_abbrind]) == 0;
672 	}
673 	return result;
674 }
675 
676 static const int	mon_lengths[2][MONSPERYEAR] = {
677 	{ 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 },
678 	{ 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }
679 };
680 
681 static const int	year_lengths[2] = {
682 	DAYSPERNYEAR, DAYSPERLYEAR
683 };
684 
685 /*
686 ** Given a pointer into a time zone string, scan until a character that is not
687 ** a valid character in a zone name is found. Return a pointer to that
688 ** character.
689 */
690 
691 static const char *
getzname(strp)692 getzname(strp)
693 const char *	strp;
694 {
695 	char	c;
696 
697 	while ((c = *strp) != '\0' && !is_digit(c) && c != ',' && c != '-' &&
698 		c != '+')
699 			++strp;
700 	return strp;
701 }
702 
703 /*
704 ** Given a pointer into an extended time zone string, scan until the ending
705 ** delimiter of the zone name is located. Return a pointer to the delimiter.
706 **
707 ** As with getzname above, the legal character set is actually quite
708 ** restricted, with other characters producing undefined results.
709 ** We don't do any checking here; checking is done later in common-case code.
710 */
711 
712 static const char *
getqzname(register const char * strp,const int delim)713 getqzname(register const char *strp, const int delim)
714 {
715 	register int	c;
716 
717 	while ((c = *strp) != '\0' && c != delim)
718 		++strp;
719 	return strp;
720 }
721 
722 /*
723 ** Given a pointer into a time zone string, extract a number from that string.
724 ** Check that the number is within a specified range; if it is not, return
725 ** NULL.
726 ** Otherwise, return a pointer to the first character not part of the number.
727 */
728 
729 static const char *
getnum(strp,nump,min,max)730 getnum(strp, nump, min, max)
731 const char *	strp;
732 int * const		nump;
733 const int		min;
734 const int		max;
735 {
736 	char	c;
737 	int	num;
738 
739 	if (strp == NULL || !is_digit(c = *strp))
740 		return NULL;
741 	num = 0;
742 	do {
743 		num = num * 10 + (c - '0');
744 		if (num > max)
745 			return NULL;	/* illegal value */
746 		c = *++strp;
747 	} while (is_digit(c));
748 	if (num < min)
749 		return NULL;		/* illegal value */
750 	*nump = num;
751 	return strp;
752 }
753 
754 /*
755 ** Given a pointer into a time zone string, extract a number of seconds,
756 ** in hh[:mm[:ss]] form, from the string.
757 ** If any error occurs, return NULL.
758 ** Otherwise, return a pointer to the first character not part of the number
759 ** of seconds.
760 */
761 
762 static const char *
getsecs(strp,secsp)763 getsecs(strp, secsp)
764 const char *	strp;
765 long * const		secsp;
766 {
767 	int	num;
768 
769 	/*
770 	** `HOURSPERDAY * DAYSPERWEEK - 1' allows quasi-Posix rules like
771 	** "M10.4.6/26", which does not conform to Posix,
772 	** but which specifies the equivalent of
773 	** ``02:00 on the first Sunday on or after 23 Oct''.
774 	*/
775 	strp = getnum(strp, &num, 0, HOURSPERDAY * DAYSPERWEEK - 1);
776 	if (strp == NULL)
777 		return NULL;
778 	*secsp = num * (long) SECSPERHOUR;
779 	if (*strp == ':') {
780 		++strp;
781 		strp = getnum(strp, &num, 0, MINSPERHOUR - 1);
782 		if (strp == NULL)
783 			return NULL;
784 		*secsp += num * SECSPERMIN;
785 		if (*strp == ':') {
786 			++strp;
787 			/* `SECSPERMIN' allows for leap seconds. */
788 			strp = getnum(strp, &num, 0, SECSPERMIN);
789 			if (strp == NULL)
790 				return NULL;
791 			*secsp += num;
792 		}
793 	}
794 	return strp;
795 }
796 
797 /*
798 ** Given a pointer into a time zone string, extract an offset, in
799 ** [+-]hh[:mm[:ss]] form, from the string.
800 ** If any error occurs, return NULL.
801 ** Otherwise, return a pointer to the first character not part of the time.
802 */
803 
804 static const char *
getoffset(strp,offsetp)805 getoffset(strp, offsetp)
806 const char *	strp;
807 long * const		offsetp;
808 {
809 	int	neg = 0;
810 
811 	if (*strp == '-') {
812 		neg = 1;
813 		++strp;
814 	} else if (*strp == '+')
815 		++strp;
816 	strp = getsecs(strp, offsetp);
817 	if (strp == NULL)
818 		return NULL;		/* illegal time */
819 	if (neg)
820 		*offsetp = -*offsetp;
821 	return strp;
822 }
823 
824 /*
825 ** Given a pointer into a time zone string, extract a rule in the form
826 ** date[/time]. See POSIX section 8 for the format of "date" and "time".
827 ** If a valid rule is not found, return NULL.
828 ** Otherwise, return a pointer to the first character not part of the rule.
829 */
830 
831 static const char *
getrule(strp,rulep)832 getrule(strp, rulep)
833 const char *			strp;
834 struct rule * const	rulep;
835 {
836 	if (*strp == 'J') {
837 		/*
838 		** Julian day.
839 		*/
840 		rulep->r_type = JULIAN_DAY;
841 		++strp;
842 		strp = getnum(strp, &rulep->r_day, 1, DAYSPERNYEAR);
843 	} else if (*strp == 'M') {
844 		/*
845 		** Month, week, day.
846 		*/
847 		rulep->r_type = MONTH_NTH_DAY_OF_WEEK;
848 		++strp;
849 		strp = getnum(strp, &rulep->r_mon, 1, MONSPERYEAR);
850 		if (strp == NULL)
851 			return NULL;
852 		if (*strp++ != '.')
853 			return NULL;
854 		strp = getnum(strp, &rulep->r_week, 1, 5);
855 		if (strp == NULL)
856 			return NULL;
857 		if (*strp++ != '.')
858 			return NULL;
859 		strp = getnum(strp, &rulep->r_day, 0, DAYSPERWEEK - 1);
860 	} else if (is_digit(*strp)) {
861 		/*
862 		** Day of year.
863 		*/
864 		rulep->r_type = DAY_OF_YEAR;
865 		strp = getnum(strp, &rulep->r_day, 0, DAYSPERLYEAR - 1);
866 	} else	return NULL;		/* invalid format */
867 	if (strp == NULL)
868 		return NULL;
869 	if (*strp == '/') {
870 		/*
871 		** Time specified.
872 		*/
873 		++strp;
874 		strp = getsecs(strp, &rulep->r_time);
875 	} else	rulep->r_time = 2 * SECSPERHOUR;	/* default = 2:00:00 */
876 	return strp;
877 }
878 
879 /*
880 ** Given the Epoch-relative time of January 1, 00:00:00 UTC, in a year, the
881 ** year, a rule, and the offset from UTC at the time that rule takes effect,
882 ** calculate the Epoch-relative time that rule takes effect.
883 */
884 
885 static time_t
transtime(janfirst,year,rulep,offset)886 transtime(janfirst, year, rulep, offset)
887 const time_t				janfirst;
888 const int				year;
889 const struct rule * const	rulep;
890 const long				offset;
891 {
892 	int	leapyear;
893 	time_t	value;
894 	int	i;
895 	int		d, m1, yy0, yy1, yy2, dow;
896 
897 	INITIALIZE(value);
898 	leapyear = isleap(year);
899 	switch (rulep->r_type) {
900 
901 	case JULIAN_DAY:
902 		/*
903 		** Jn - Julian day, 1 == January 1, 60 == March 1 even in leap
904 		** years.
905 		** In non-leap years, or if the day number is 59 or less, just
906 		** add SECSPERDAY times the day number-1 to the time of
907 		** January 1, midnight, to get the day.
908 		*/
909 		value = janfirst + (rulep->r_day - 1) * SECSPERDAY;
910 		if (leapyear && rulep->r_day >= 60)
911 			value += SECSPERDAY;
912 		break;
913 
914 	case DAY_OF_YEAR:
915 		/*
916 		** n - day of year.
917 		** Just add SECSPERDAY times the day number to the time of
918 		** January 1, midnight, to get the day.
919 		*/
920 		value = janfirst + rulep->r_day * SECSPERDAY;
921 		break;
922 
923 	case MONTH_NTH_DAY_OF_WEEK:
924 		/*
925 		** Mm.n.d - nth "dth day" of month m.
926 		*/
927 		value = janfirst;
928 		for (i = 0; i < rulep->r_mon - 1; ++i)
929 			value += mon_lengths[leapyear][i] * SECSPERDAY;
930 
931 		/*
932 		** Use Zeller's Congruence to get day-of-week of first day of
933 		** month.
934 		*/
935 		m1 = (rulep->r_mon + 9) % 12 + 1;
936 		yy0 = (rulep->r_mon <= 2) ? (year - 1) : year;
937 		yy1 = yy0 / 100;
938 		yy2 = yy0 % 100;
939 		dow = ((26 * m1 - 2) / 10 +
940 			1 + yy2 + yy2 / 4 + yy1 / 4 - 2 * yy1) % 7;
941 		if (dow < 0)
942 			dow += DAYSPERWEEK;
943 
944 		/*
945 		** "dow" is the day-of-week of the first day of the month. Get
946 		** the day-of-month (zero-origin) of the first "dow" day of the
947 		** month.
948 		*/
949 		d = rulep->r_day - dow;
950 		if (d < 0)
951 			d += DAYSPERWEEK;
952 		for (i = 1; i < rulep->r_week; ++i) {
953 			if (d + DAYSPERWEEK >=
954 				mon_lengths[leapyear][rulep->r_mon - 1])
955 					break;
956 			d += DAYSPERWEEK;
957 		}
958 
959 		/*
960 		** "d" is the day-of-month (zero-origin) of the day we want.
961 		*/
962 		value += d * SECSPERDAY;
963 		break;
964 	}
965 
966 	/*
967 	** "value" is the Epoch-relative time of 00:00:00 UTC on the day in
968 	** question. To get the Epoch-relative time of the specified local
969 	** time on that day, add the transition time and the current offset
970 	** from UTC.
971 	*/
972 	return value + rulep->r_time + offset;
973 }
974 
975 /*
976 ** Given a POSIX section 8-style TZ string, fill in the rule tables as
977 ** appropriate.
978 */
979 
980 static int
tzparse(name,sp,lastditch)981 tzparse(name, sp, lastditch)
982 const char *			name;
983 struct state * const	sp;
984 const int			lastditch;
985 {
986 	const char *			stdname;
987 	const char *			dstname;
988 	size_t				stdlen;
989 	size_t				dstlen;
990 	long				stdoffset;
991 	long				dstoffset;
992 	time_t *		atp;
993 	unsigned char *	typep;
994 	char *			cp;
995 	int			load_result;
996 
997 	INITIALIZE(dstname);
998 	stdname = name;
999 	if (lastditch) {
1000 		stdlen = strlen(name);	/* length of standard zone name */
1001 		name += stdlen;
1002 		if (stdlen >= sizeof sp->chars)
1003 			stdlen = (sizeof sp->chars) - 1;
1004 		stdoffset = 0;
1005 	} else {
1006 		if (*name == '<') {
1007 			name++;
1008 			stdname = name;
1009 			name = getqzname(name, '>');
1010 			if (*name != '>')
1011 				return (-1);
1012 			stdlen = name - stdname;
1013 			name++;
1014 		} else {
1015 			name = getzname(name);
1016 			stdlen = name - stdname;
1017 		}
1018 		if (*name == '\0')
1019 			return -1;	/* was "stdoffset = 0;" */
1020 		else {
1021 			name = getoffset(name, &stdoffset);
1022 			if (name == NULL)
1023 				return -1;
1024 		}
1025 	}
1026 	load_result = tzload(TZDEFRULES, sp, FALSE);
1027 	if (load_result != 0)
1028 		sp->leapcnt = 0;		/* so, we're off a little */
1029 	if (*name != '\0') {
1030 		if (*name == '<') {
1031 			dstname = ++name;
1032 			name = getqzname(name, '>');
1033 			if (*name != '>')
1034 				return -1;
1035 			dstlen = name - dstname;
1036 			name++;
1037 		} else {
1038 			dstname = name;
1039 			name = getzname(name);
1040 			dstlen = name - dstname; /* length of DST zone name */
1041 		}
1042 		if (*name != '\0' && *name != ',' && *name != ';') {
1043 			name = getoffset(name, &dstoffset);
1044 			if (name == NULL)
1045 				return -1;
1046 		} else	dstoffset = stdoffset - SECSPERHOUR;
1047 		if (*name == '\0' && load_result != 0)
1048 			name = TZDEFRULESTRING;
1049 		if (*name == ',' || *name == ';') {
1050 			struct rule	start;
1051 			struct rule	end;
1052 			int	year;
1053 			time_t	janfirst;
1054 			time_t		starttime;
1055 			time_t		endtime;
1056 
1057 			++name;
1058 			if ((name = getrule(name, &start)) == NULL)
1059 				return -1;
1060 			if (*name++ != ',')
1061 				return -1;
1062 			if ((name = getrule(name, &end)) == NULL)
1063 				return -1;
1064 			if (*name != '\0')
1065 				return -1;
1066 			sp->typecnt = 2;	/* standard time and DST */
1067 			/*
1068 			** Two transitions per year, from EPOCH_YEAR forward.
1069 			*/
1070 			sp->ttis[0].tt_gmtoff = -dstoffset;
1071 			sp->ttis[0].tt_isdst = 1;
1072 			sp->ttis[0].tt_abbrind = stdlen + 1;
1073 			sp->ttis[1].tt_gmtoff = -stdoffset;
1074 			sp->ttis[1].tt_isdst = 0;
1075 			sp->ttis[1].tt_abbrind = 0;
1076 			atp = sp->ats;
1077 			typep = sp->types;
1078 			janfirst = 0;
1079 			sp->timecnt = 0;
1080 			for (year = EPOCH_YEAR;
1081 			    sp->timecnt + 2 <= TZ_MAX_TIMES;
1082 			    ++year) {
1083 			    	time_t	newfirst;
1084 
1085 				starttime = transtime(janfirst, year, &start,
1086 					stdoffset);
1087 				endtime = transtime(janfirst, year, &end,
1088 					dstoffset);
1089 				if (starttime > endtime) {
1090 					*atp++ = endtime;
1091 					*typep++ = 1;	/* DST ends */
1092 					*atp++ = starttime;
1093 					*typep++ = 0;	/* DST begins */
1094 				} else {
1095 					*atp++ = starttime;
1096 					*typep++ = 0;	/* DST begins */
1097 					*atp++ = endtime;
1098 					*typep++ = 1;	/* DST ends */
1099 				}
1100 				sp->timecnt += 2;
1101 				newfirst = janfirst;
1102 				newfirst += year_lengths[isleap(year)] *
1103 					SECSPERDAY;
1104 				if (newfirst <= janfirst)
1105 					break;
1106 				janfirst = newfirst;
1107 			}
1108 		} else {
1109 			long	theirstdoffset;
1110 			long	theirdstoffset;
1111 			long	theiroffset;
1112 			int	isdst;
1113 			int	i;
1114 			int	j;
1115 
1116 			if (*name != '\0')
1117 				return -1;
1118 			/*
1119 			** Initial values of theirstdoffset and theirdstoffset.
1120 			*/
1121 			theirstdoffset = 0;
1122 			for (i = 0; i < sp->timecnt; ++i) {
1123 				j = sp->types[i];
1124 				if (!sp->ttis[j].tt_isdst) {
1125 					theirstdoffset =
1126 						-sp->ttis[j].tt_gmtoff;
1127 					break;
1128 				}
1129 			}
1130 			theirdstoffset = 0;
1131 			for (i = 0; i < sp->timecnt; ++i) {
1132 				j = sp->types[i];
1133 				if (sp->ttis[j].tt_isdst) {
1134 					theirdstoffset =
1135 						-sp->ttis[j].tt_gmtoff;
1136 					break;
1137 				}
1138 			}
1139 			/*
1140 			** Initially we're assumed to be in standard time.
1141 			*/
1142 			isdst = FALSE;
1143 			theiroffset = theirstdoffset;
1144 			/*
1145 			** Now juggle transition times and types
1146 			** tracking offsets as you do.
1147 			*/
1148 			for (i = 0; i < sp->timecnt; ++i) {
1149 				j = sp->types[i];
1150 				sp->types[i] = sp->ttis[j].tt_isdst;
1151 				if (sp->ttis[j].tt_ttisgmt) {
1152 					/* No adjustment to transition time */
1153 				} else {
1154 					/*
1155 					** If summer time is in effect, and the
1156 					** transition time was not specified as
1157 					** standard time, add the summer time
1158 					** offset to the transition time;
1159 					** otherwise, add the standard time
1160 					** offset to the transition time.
1161 					*/
1162 					/*
1163 					** Transitions from DST to DDST
1164 					** will effectively disappear since
1165 					** POSIX provides for only one DST
1166 					** offset.
1167 					*/
1168 					if (isdst && !sp->ttis[j].tt_ttisstd) {
1169 						sp->ats[i] += dstoffset -
1170 							theirdstoffset;
1171 					} else {
1172 						sp->ats[i] += stdoffset -
1173 							theirstdoffset;
1174 					}
1175 				}
1176 				theiroffset = -sp->ttis[j].tt_gmtoff;
1177 				if (sp->ttis[j].tt_isdst)
1178 					theirdstoffset = theiroffset;
1179 				else	theirstdoffset = theiroffset;
1180 			}
1181 			/*
1182 			** Finally, fill in ttis.
1183 			** ttisstd and ttisgmt need not be handled.
1184 			*/
1185 			sp->ttis[0].tt_gmtoff = -stdoffset;
1186 			sp->ttis[0].tt_isdst = FALSE;
1187 			sp->ttis[0].tt_abbrind = 0;
1188 			sp->ttis[1].tt_gmtoff = -dstoffset;
1189 			sp->ttis[1].tt_isdst = TRUE;
1190 			sp->ttis[1].tt_abbrind = stdlen + 1;
1191 			sp->typecnt = 2;
1192 		}
1193 	} else {
1194 		dstlen = 0;
1195 		sp->typecnt = 1;		/* only standard time */
1196 		sp->timecnt = 0;
1197 		sp->ttis[0].tt_gmtoff = -stdoffset;
1198 		sp->ttis[0].tt_isdst = 0;
1199 		sp->ttis[0].tt_abbrind = 0;
1200 	}
1201 	sp->charcnt = stdlen + 1;
1202 	if (dstlen != 0)
1203 		sp->charcnt += dstlen + 1;
1204 	if ((size_t) sp->charcnt > sizeof sp->chars)
1205 		return -1;
1206 	cp = sp->chars;
1207 	(void) strncpy(cp, stdname, stdlen);
1208 	cp += stdlen;
1209 	*cp++ = '\0';
1210 	if (dstlen != 0) {
1211 		(void) strncpy(cp, dstname, dstlen);
1212 		*(cp + dstlen) = '\0';
1213 	}
1214 	return 0;
1215 }
1216 
1217 static void
gmtload(struct state * const sp)1218 gmtload(struct state *const sp)
1219 {
1220 	if (tzload(gmt, sp, TRUE) != 0)
1221 		(void) tzparse(gmt, sp, TRUE);
1222 }
1223 
1224 static void
tzsetwall_basic(int rdlocked)1225 tzsetwall_basic(int rdlocked)
1226 {
1227 	if (!rdlocked)
1228 		_RWLOCK_RDLOCK(&lcl_rwlock);
1229 	if (lcl_is_set < 0) {
1230 		if (!rdlocked)
1231 			_RWLOCK_UNLOCK(&lcl_rwlock);
1232 		return;
1233 	}
1234 	_RWLOCK_UNLOCK(&lcl_rwlock);
1235 
1236 	_RWLOCK_WRLOCK(&lcl_rwlock);
1237 	lcl_is_set = -1;
1238 
1239 #ifdef ALL_STATE
1240 	if (lclptr == NULL) {
1241 		lclptr = calloc(1, sizeof *lclptr);
1242 		if (lclptr == NULL) {
1243 			settzname();	/* all we can do */
1244 			_RWLOCK_UNLOCK(&lcl_rwlock);
1245 			if (rdlocked)
1246 				_RWLOCK_RDLOCK(&lcl_rwlock);
1247 			return;
1248 		}
1249 	}
1250 #endif /* defined ALL_STATE */
1251 	if (tzload((char *) NULL, lclptr, TRUE) != 0)
1252 		gmtload(lclptr);
1253 	settzname();
1254 	_RWLOCK_UNLOCK(&lcl_rwlock);
1255 
1256 	if (rdlocked)
1257 		_RWLOCK_RDLOCK(&lcl_rwlock);
1258 }
1259 
1260 void
tzsetwall(void)1261 tzsetwall(void)
1262 {
1263 	tzsetwall_basic(0);
1264 }
1265 
1266 static void
tzset_basic(int rdlocked)1267 tzset_basic(int rdlocked)
1268 {
1269 	const char *	name;
1270 
1271 	name = getenv("TZ");
1272 	if (name == NULL) {
1273 		tzsetwall_basic(rdlocked);
1274 		return;
1275 	}
1276 
1277 	if (!rdlocked)
1278 		_RWLOCK_RDLOCK(&lcl_rwlock);
1279 	if (lcl_is_set > 0 && strcmp(lcl_TZname, name) == 0) {
1280 		if (!rdlocked)
1281 			_RWLOCK_UNLOCK(&lcl_rwlock);
1282 		return;
1283 	}
1284 	_RWLOCK_UNLOCK(&lcl_rwlock);
1285 
1286 	_RWLOCK_WRLOCK(&lcl_rwlock);
1287 	lcl_is_set = strlen(name) < sizeof lcl_TZname;
1288 	if (lcl_is_set)
1289 		(void) strcpy(lcl_TZname, name);
1290 
1291 #ifdef ALL_STATE
1292 	if (lclptr == NULL) {
1293 		lclptr = (struct state *) calloc(1, sizeof *lclptr);
1294 		if (lclptr == NULL) {
1295 			settzname();	/* all we can do */
1296 			_RWLOCK_UNLOCK(&lcl_rwlock);
1297 			if (rdlocked)
1298 				_RWLOCK_RDLOCK(&lcl_rwlock);
1299 			return;
1300 		}
1301 	}
1302 #endif /* defined ALL_STATE */
1303 	if (*name == '\0') {
1304 		/*
1305 		** User wants it fast rather than right.
1306 		*/
1307 		lclptr->leapcnt = 0;		/* so, we're off a little */
1308 		lclptr->timecnt = 0;
1309 		lclptr->typecnt = 0;
1310 		lclptr->ttis[0].tt_isdst = 0;
1311 		lclptr->ttis[0].tt_gmtoff = 0;
1312 		lclptr->ttis[0].tt_abbrind = 0;
1313 		(void) strcpy(lclptr->chars, gmt);
1314 	} else if (tzload(name, lclptr, TRUE) != 0)
1315 		if (name[0] == ':' || tzparse(name, lclptr, FALSE) != 0)
1316 			(void) gmtload(lclptr);
1317 	settzname();
1318 	_RWLOCK_UNLOCK(&lcl_rwlock);
1319 
1320 	if (rdlocked)
1321 		_RWLOCK_RDLOCK(&lcl_rwlock);
1322 }
1323 
1324 void
tzset(void)1325 tzset(void)
1326 {
1327 	tzset_basic(0);
1328 }
1329 
1330 /*
1331 ** The easy way to behave "as if no library function calls" localtime
1332 ** is to not call it--so we drop its guts into "localsub", which can be
1333 ** freely called. (And no, the PANS doesn't require the above behavior--
1334 ** but it *is* desirable.)
1335 **
1336 ** The unused offset argument is for the benefit of mktime variants.
1337 */
1338 
1339 /*ARGSUSED*/
1340 static struct tm *
localsub(const time_t * const timep,const long offset,struct tm * const tmp)1341 localsub(const time_t *const timep, const long offset, struct tm *const tmp)
1342 {
1343 	struct state *		sp;
1344 	const struct ttinfo *	ttisp;
1345 	int			i;
1346 	struct tm *		result;
1347 	const time_t		t = *timep;
1348 
1349 	sp = lclptr;
1350 #ifdef ALL_STATE
1351 	if (sp == NULL)
1352 		return gmtsub(timep, offset, tmp);
1353 #endif /* defined ALL_STATE */
1354 	if ((sp->goback && t < sp->ats[0]) ||
1355 		(sp->goahead && t > sp->ats[sp->timecnt - 1])) {
1356 			time_t			newt = t;
1357 			register time_t		seconds;
1358 			register time_t		tcycles;
1359 			register int_fast64_t	icycles;
1360 
1361 			if (t < sp->ats[0])
1362 				seconds = sp->ats[0] - t;
1363 			else	seconds = t - sp->ats[sp->timecnt - 1];
1364 			--seconds;
1365 			tcycles = seconds / YEARSPERREPEAT / AVGSECSPERYEAR;
1366 			++tcycles;
1367 			icycles = tcycles;
1368 			if (tcycles - icycles >= 1 || icycles - tcycles >= 1)
1369 				return NULL;
1370 			seconds = icycles;
1371 			seconds *= YEARSPERREPEAT;
1372 			seconds *= AVGSECSPERYEAR;
1373 			if (t < sp->ats[0])
1374 				newt += seconds;
1375 			else	newt -= seconds;
1376 			if (newt < sp->ats[0] ||
1377 				newt > sp->ats[sp->timecnt - 1])
1378 					return NULL;	/* "cannot happen" */
1379 			result = localsub(&newt, offset, tmp);
1380 			if (result == tmp) {
1381 				register time_t	newy;
1382 
1383 				newy = tmp->tm_year;
1384 				if (t < sp->ats[0])
1385 					newy -= icycles * YEARSPERREPEAT;
1386 				else	newy += icycles * YEARSPERREPEAT;
1387 				tmp->tm_year = newy;
1388 				if (tmp->tm_year != newy)
1389 					return NULL;
1390 			}
1391 			return result;
1392 	}
1393 	if (sp->timecnt == 0 || t < sp->ats[0]) {
1394 		i = 0;
1395 		while (sp->ttis[i].tt_isdst)
1396 			if (++i >= sp->typecnt) {
1397 				i = 0;
1398 				break;
1399 			}
1400 	} else {
1401 		register int	lo = 1;
1402 		register int	hi = sp->timecnt;
1403 
1404 		while (lo < hi) {
1405 			register int	mid = (lo + hi) >> 1;
1406 
1407 			if (t < sp->ats[mid])
1408 				hi = mid;
1409 			else	lo = mid + 1;
1410 		}
1411 		i = (int) sp->types[lo - 1];
1412 	}
1413 	ttisp = &sp->ttis[i];
1414 	/*
1415 	** To get (wrong) behavior that's compatible with System V Release 2.0
1416 	** you'd replace the statement below with
1417 	**	t += ttisp->tt_gmtoff;
1418 	**	timesub(&t, 0L, sp, tmp);
1419 	*/
1420 	result = timesub(&t, ttisp->tt_gmtoff, sp, tmp);
1421 	tmp->tm_isdst = ttisp->tt_isdst;
1422 	tzname[tmp->tm_isdst] = &sp->chars[ttisp->tt_abbrind];
1423 #ifdef TM_ZONE
1424 	tmp->TM_ZONE = &sp->chars[ttisp->tt_abbrind];
1425 #endif /* defined TM_ZONE */
1426 	return result;
1427 }
1428 
1429 static void
localtime_key_init(void)1430 localtime_key_init(void)
1431 {
1432 
1433 	localtime_key_error = _pthread_key_create(&localtime_key, free);
1434 }
1435 
1436 struct tm *
localtime(const time_t * const timep)1437 localtime(const time_t *const timep)
1438 {
1439 	struct tm *p_tm;
1440 
1441 	if (__isthreaded != 0) {
1442 		_pthread_once(&localtime_once, localtime_key_init);
1443 		if (localtime_key_error != 0) {
1444 			errno = localtime_key_error;
1445 			return(NULL);
1446 		}
1447 		p_tm = _pthread_getspecific(localtime_key);
1448 		if (p_tm == NULL) {
1449 			if ((p_tm = (struct tm *)malloc(sizeof(struct tm)))
1450 			    == NULL)
1451 				return(NULL);
1452 			_pthread_setspecific(localtime_key, p_tm);
1453 		}
1454 		_RWLOCK_RDLOCK(&lcl_rwlock);
1455 		tzset_basic(1);
1456 		localsub(timep, 0L, p_tm);
1457 		_RWLOCK_UNLOCK(&lcl_rwlock);
1458 		return(p_tm);
1459 	} else {
1460 		tzset_basic(0);
1461 		localsub(timep, 0L, &tm);
1462 		return(&tm);
1463 	}
1464 }
1465 
1466 /*
1467 ** Re-entrant version of localtime.
1468 */
1469 
1470 struct tm *
localtime_r(const time_t * const timep,struct tm * tmp)1471 localtime_r(const time_t *const timep, struct tm *tmp)
1472 {
1473 	_RWLOCK_RDLOCK(&lcl_rwlock);
1474 	tzset_basic(1);
1475 	localsub(timep, 0L, tmp);
1476 	_RWLOCK_UNLOCK(&lcl_rwlock);
1477 	return tmp;
1478 }
1479 
1480 static void
gmt_init(void)1481 gmt_init(void)
1482 {
1483 
1484 #ifdef ALL_STATE
1485 	gmtptr = (struct state *) calloc(1, sizeof *gmtptr);
1486 	if (gmtptr != NULL)
1487 #endif /* defined ALL_STATE */
1488 		gmtload(gmtptr);
1489 }
1490 
1491 /*
1492 ** gmtsub is to gmtime as localsub is to localtime.
1493 */
1494 
1495 static struct tm *
gmtsub(timep,offset,tmp)1496 gmtsub(timep, offset, tmp)
1497 const time_t * const	timep;
1498 const long		offset;
1499 struct tm * const	tmp;
1500 {
1501 	register struct tm *	result;
1502 
1503 	_once(&gmt_once, gmt_init);
1504 	result = timesub(timep, offset, gmtptr, tmp);
1505 #ifdef TM_ZONE
1506 	/*
1507 	** Could get fancy here and deliver something such as
1508 	** "UTC+xxxx" or "UTC-xxxx" if offset is non-zero,
1509 	** but this is no time for a treasure hunt.
1510 	*/
1511 	if (offset != 0)
1512 		tmp->TM_ZONE = wildabbr;
1513 	else {
1514 #ifdef ALL_STATE
1515 		if (gmtptr == NULL)
1516 			tmp->TM_ZONE = gmt;
1517 		else	tmp->TM_ZONE = gmtptr->chars;
1518 #endif /* defined ALL_STATE */
1519 #ifndef ALL_STATE
1520 		tmp->TM_ZONE = gmtptr->chars;
1521 #endif /* State Farm */
1522 	}
1523 #endif /* defined TM_ZONE */
1524 	return result;
1525 }
1526 
1527 static void
gmtime_key_init(void)1528 gmtime_key_init(void)
1529 {
1530 
1531 	gmtime_key_error = _pthread_key_create(&gmtime_key, free);
1532 }
1533 
1534 struct tm *
gmtime(const time_t * const timep)1535 gmtime(const time_t *const timep)
1536 {
1537 	struct tm *p_tm;
1538 
1539 	if (__isthreaded != 0) {
1540 		_pthread_once(&gmtime_once, gmtime_key_init);
1541 		if (gmtime_key_error != 0) {
1542 			errno = gmtime_key_error;
1543 			return(NULL);
1544 		}
1545 		/*
1546 		 * Changed to follow POSIX.1 threads standard, which
1547 		 * is what BSD currently has.
1548 		 */
1549 		if ((p_tm = _pthread_getspecific(gmtime_key)) == NULL) {
1550 			if ((p_tm = (struct tm *)malloc(sizeof(struct tm)))
1551 			    == NULL) {
1552 				return(NULL);
1553 			}
1554 			_pthread_setspecific(gmtime_key, p_tm);
1555 		}
1556 		gmtsub(timep, 0L, p_tm);
1557 		return(p_tm);
1558 	}
1559 	else {
1560 		gmtsub(timep, 0L, &tm);
1561 		return(&tm);
1562 	}
1563 }
1564 
1565 /*
1566 * Re-entrant version of gmtime.
1567 */
1568 
1569 struct tm *
gmtime_r(const time_t * const timep,struct tm * tmp)1570 gmtime_r(const time_t *const timep, struct tm *tmp)
1571 {
1572 	return gmtsub(timep, 0L, tmp);
1573 }
1574 
1575 #ifdef STD_INSPIRED
1576 
1577 struct tm *
offtime(const time_t * const timep,const long offset)1578 offtime(const time_t *const timep, const long offset)
1579 {
1580 	return gmtsub(timep, offset, &tm);
1581 }
1582 
1583 #endif /* defined STD_INSPIRED */
1584 
1585 /*
1586 ** Return the number of leap years through the end of the given year
1587 ** where, to make the math easy, the answer for year zero is defined as zero.
1588 */
1589 
1590 static int
leaps_thru_end_of(y)1591 leaps_thru_end_of(y)
1592 register const int	y;
1593 {
1594 	return (y >= 0) ? (y / 4 - y / 100 + y / 400) :
1595 		-(leaps_thru_end_of(-(y + 1)) + 1);
1596 }
1597 
1598 static struct tm *
timesub(timep,offset,sp,tmp)1599 timesub(timep, offset, sp, tmp)
1600 const time_t * const			timep;
1601 const long				offset;
1602 const struct state * const	sp;
1603 struct tm * const		tmp;
1604 {
1605 	const struct lsinfo *	lp;
1606 	time_t			tdays;
1607 	int			idays;	/* unsigned would be so 2003 */
1608 	long			rem;
1609 	int			y;
1610 	const int *		ip;
1611 	long			corr;
1612 	int			hit;
1613 	int			i;
1614 
1615 	corr = 0;
1616 	hit = 0;
1617 #ifdef ALL_STATE
1618 	i = (sp == NULL) ? 0 : sp->leapcnt;
1619 #endif /* defined ALL_STATE */
1620 #ifndef ALL_STATE
1621 	i = sp->leapcnt;
1622 #endif /* State Farm */
1623 	while (--i >= 0) {
1624 		lp = &sp->lsis[i];
1625 		if (*timep >= lp->ls_trans) {
1626 			if (*timep == lp->ls_trans) {
1627 				hit = ((i == 0 && lp->ls_corr > 0) ||
1628 					lp->ls_corr > sp->lsis[i - 1].ls_corr);
1629 				if (hit)
1630 					while (i > 0 &&
1631 						sp->lsis[i].ls_trans ==
1632 						sp->lsis[i - 1].ls_trans + 1 &&
1633 						sp->lsis[i].ls_corr ==
1634 						sp->lsis[i - 1].ls_corr + 1) {
1635 							++hit;
1636 							--i;
1637 					}
1638 			}
1639 			corr = lp->ls_corr;
1640 			break;
1641 		}
1642 	}
1643 	y = EPOCH_YEAR;
1644 	tdays = *timep / SECSPERDAY;
1645 	rem = *timep - tdays * SECSPERDAY;
1646 	while (tdays < 0 || tdays >= year_lengths[isleap(y)]) {
1647 		int		newy;
1648 		register time_t	tdelta;
1649 		register int	idelta;
1650 		register int	leapdays;
1651 
1652 		tdelta = tdays / DAYSPERLYEAR;
1653 		idelta = tdelta;
1654 		if (tdelta - idelta >= 1 || idelta - tdelta >= 1)
1655 			return NULL;
1656 		if (idelta == 0)
1657 			idelta = (tdays < 0) ? -1 : 1;
1658 		newy = y;
1659 		if (increment_overflow(&newy, idelta))
1660 			return NULL;
1661 		leapdays = leaps_thru_end_of(newy - 1) -
1662 			leaps_thru_end_of(y - 1);
1663 		tdays -= ((time_t) newy - y) * DAYSPERNYEAR;
1664 		tdays -= leapdays;
1665 		y = newy;
1666 	}
1667 	{
1668 		register long	seconds;
1669 
1670 		seconds = tdays * SECSPERDAY + 0.5;
1671 		tdays = seconds / SECSPERDAY;
1672 		rem += seconds - tdays * SECSPERDAY;
1673 	}
1674 	/*
1675 	** Given the range, we can now fearlessly cast...
1676 	*/
1677 	idays = tdays;
1678 	rem += offset - corr;
1679 	while (rem < 0) {
1680 		rem += SECSPERDAY;
1681 		--idays;
1682 	}
1683 	while (rem >= SECSPERDAY) {
1684 		rem -= SECSPERDAY;
1685 		++idays;
1686 	}
1687 	while (idays < 0) {
1688 		if (increment_overflow(&y, -1))
1689 			return NULL;
1690 		idays += year_lengths[isleap(y)];
1691 	}
1692 	while (idays >= year_lengths[isleap(y)]) {
1693 		idays -= year_lengths[isleap(y)];
1694 		if (increment_overflow(&y, 1))
1695 			return NULL;
1696 	}
1697 	tmp->tm_year = y;
1698 	if (increment_overflow(&tmp->tm_year, -TM_YEAR_BASE))
1699 		return NULL;
1700 	tmp->tm_yday = idays;
1701 	/*
1702 	** The "extra" mods below avoid overflow problems.
1703 	*/
1704 	tmp->tm_wday = EPOCH_WDAY +
1705 		((y - EPOCH_YEAR) % DAYSPERWEEK) *
1706 		(DAYSPERNYEAR % DAYSPERWEEK) +
1707 		leaps_thru_end_of(y - 1) -
1708 		leaps_thru_end_of(EPOCH_YEAR - 1) +
1709 		idays;
1710 	tmp->tm_wday %= DAYSPERWEEK;
1711 	if (tmp->tm_wday < 0)
1712 		tmp->tm_wday += DAYSPERWEEK;
1713 	tmp->tm_hour = (int) (rem / SECSPERHOUR);
1714 	rem %= SECSPERHOUR;
1715 	tmp->tm_min = (int) (rem / SECSPERMIN);
1716 	/*
1717 	** A positive leap second requires a special
1718 	** representation. This uses "... ??:59:60" et seq.
1719 	*/
1720 	tmp->tm_sec = (int) (rem % SECSPERMIN) + hit;
1721 	ip = mon_lengths[isleap(y)];
1722 	for (tmp->tm_mon = 0; idays >= ip[tmp->tm_mon]; ++(tmp->tm_mon))
1723 		idays -= ip[tmp->tm_mon];
1724 	tmp->tm_mday = (int) (idays + 1);
1725 	tmp->tm_isdst = 0;
1726 #ifdef TM_GMTOFF
1727 	tmp->TM_GMTOFF = offset;
1728 #endif /* defined TM_GMTOFF */
1729 	return tmp;
1730 }
1731 
1732 char *
ctime(const time_t * const timep)1733 ctime(const time_t *const timep)
1734 {
1735 /*
1736 ** Section 4.12.3.2 of X3.159-1989 requires that
1737 **	The ctime function converts the calendar time pointed to by timer
1738 **	to local time in the form of a string. It is equivalent to
1739 **		asctime(localtime(timer))
1740 */
1741 	return asctime(localtime(timep));
1742 }
1743 
1744 char *
ctime_r(const time_t * const timep,char * buf)1745 ctime_r(const time_t *const timep, char *buf)
1746 {
1747 	struct tm	mytm;
1748 
1749 	return asctime_r(localtime_r(timep, &mytm), buf);
1750 }
1751 
1752 /*
1753 ** Adapted from code provided by Robert Elz, who writes:
1754 **	The "best" way to do mktime I think is based on an idea of Bob
1755 **	Kridle's (so its said...) from a long time ago.
1756 **	It does a binary search of the time_t space. Since time_t's are
1757 **	just 32 bits, its a max of 32 iterations (even at 64 bits it
1758 **	would still be very reasonable).
1759 */
1760 
1761 #ifndef WRONG
1762 #define WRONG	(-1)
1763 #endif /* !defined WRONG */
1764 
1765 /*
1766 ** Simplified normalize logic courtesy Paul Eggert.
1767 */
1768 
1769 static int
increment_overflow(number,delta)1770 increment_overflow(number, delta)
1771 int *	number;
1772 int	delta;
1773 {
1774 	int	number0;
1775 
1776 	number0 = *number;
1777 	*number += delta;
1778 	return (*number < number0) != (delta < 0);
1779 }
1780 
1781 static int
long_increment_overflow(number,delta)1782 long_increment_overflow(number, delta)
1783 long *	number;
1784 int	delta;
1785 {
1786 	long	number0;
1787 
1788 	number0 = *number;
1789 	*number += delta;
1790 	return (*number < number0) != (delta < 0);
1791 }
1792 
1793 static int
normalize_overflow(int * const tensptr,int * const unitsptr,const int base)1794 normalize_overflow(int *const tensptr, int *const unitsptr, const int base)
1795 {
1796 	int	tensdelta;
1797 
1798 	tensdelta = (*unitsptr >= 0) ?
1799 		(*unitsptr / base) :
1800 		(-1 - (-1 - *unitsptr) / base);
1801 	*unitsptr -= tensdelta * base;
1802 	return increment_overflow(tensptr, tensdelta);
1803 }
1804 
1805 static int
long_normalize_overflow(long * const tensptr,int * const unitsptr,const int base)1806 long_normalize_overflow(long *const tensptr, int *const unitsptr, const int base)
1807 {
1808 	register int	tensdelta;
1809 
1810 	tensdelta = (*unitsptr >= 0) ?
1811 		(*unitsptr / base) :
1812 		(-1 - (-1 - *unitsptr) / base);
1813 	*unitsptr -= tensdelta * base;
1814 	return long_increment_overflow(tensptr, tensdelta);
1815 }
1816 
1817 static int
tmcomp(atmp,btmp)1818 tmcomp(atmp, btmp)
1819 const struct tm * const atmp;
1820 const struct tm * const btmp;
1821 {
1822 	int	result;
1823 
1824 	if ((result = (atmp->tm_year - btmp->tm_year)) == 0 &&
1825 		(result = (atmp->tm_mon - btmp->tm_mon)) == 0 &&
1826 		(result = (atmp->tm_mday - btmp->tm_mday)) == 0 &&
1827 		(result = (atmp->tm_hour - btmp->tm_hour)) == 0 &&
1828 		(result = (atmp->tm_min - btmp->tm_min)) == 0)
1829 			result = atmp->tm_sec - btmp->tm_sec;
1830 	return result;
1831 }
1832 
1833 static time_t
time2sub(struct tm * const tmp,struct tm * (* const funcp)(const time_t *,long,struct tm *),const long offset,int * const okayp,const int do_norm_secs)1834 time2sub(struct tm *const tmp,
1835 	 struct tm *(*const funcp)(const time_t *, long, struct tm *),
1836 	 const long offset,
1837 	 int *const okayp,
1838 	 const int do_norm_secs)
1839 {
1840 	const struct state *	sp;
1841 	int			dir;
1842 	int			i, j;
1843 	int			saved_seconds;
1844 	long			li;
1845 	time_t			lo;
1846 	time_t			hi;
1847 	long			y;
1848 	time_t			newt;
1849 	time_t			t;
1850 	struct tm		yourtm, mytm;
1851 
1852 	*okayp = FALSE;
1853 	yourtm = *tmp;
1854 	if (do_norm_secs) {
1855 		if (normalize_overflow(&yourtm.tm_min, &yourtm.tm_sec,
1856 			SECSPERMIN))
1857 				return WRONG;
1858 	}
1859 	if (normalize_overflow(&yourtm.tm_hour, &yourtm.tm_min, MINSPERHOUR))
1860 		return WRONG;
1861 	if (normalize_overflow(&yourtm.tm_mday, &yourtm.tm_hour, HOURSPERDAY))
1862 		return WRONG;
1863 	y = yourtm.tm_year;
1864 	if (long_normalize_overflow(&y, &yourtm.tm_mon, MONSPERYEAR))
1865 		return WRONG;
1866 	/*
1867 	** Turn y into an actual year number for now.
1868 	** It is converted back to an offset from TM_YEAR_BASE later.
1869 	*/
1870 	if (long_increment_overflow(&y, TM_YEAR_BASE))
1871 		return WRONG;
1872 	while (yourtm.tm_mday <= 0) {
1873 		if (long_increment_overflow(&y, -1))
1874 			return WRONG;
1875 		li = y + (1 < yourtm.tm_mon);
1876 		yourtm.tm_mday += year_lengths[isleap(li)];
1877 	}
1878 	while (yourtm.tm_mday > DAYSPERLYEAR) {
1879 		li = y + (1 < yourtm.tm_mon);
1880 		yourtm.tm_mday -= year_lengths[isleap(li)];
1881 		if (long_increment_overflow(&y, 1))
1882 			return WRONG;
1883 	}
1884 	for ( ; ; ) {
1885 		i = mon_lengths[isleap(y)][yourtm.tm_mon];
1886 		if (yourtm.tm_mday <= i)
1887 			break;
1888 		yourtm.tm_mday -= i;
1889 		if (++yourtm.tm_mon >= MONSPERYEAR) {
1890 			yourtm.tm_mon = 0;
1891 			if (long_increment_overflow(&y, 1))
1892 				return WRONG;
1893 		}
1894 	}
1895 	if (long_increment_overflow(&y, -TM_YEAR_BASE))
1896 		return WRONG;
1897 	yourtm.tm_year = y;
1898 	if (yourtm.tm_year != y)
1899 		return WRONG;
1900 	/* Don't go below 1900 for POLA */
1901 	if (yourtm.tm_year < 0)
1902 		return WRONG;
1903 	if (yourtm.tm_sec >= 0 && yourtm.tm_sec < SECSPERMIN)
1904 		saved_seconds = 0;
1905 	else if (y + TM_YEAR_BASE < EPOCH_YEAR) {
1906 		/*
1907 		** We can't set tm_sec to 0, because that might push the
1908 		** time below the minimum representable time.
1909 		** Set tm_sec to 59 instead.
1910 		** This assumes that the minimum representable time is
1911 		** not in the same minute that a leap second was deleted from,
1912 		** which is a safer assumption than using 58 would be.
1913 		*/
1914 		if (increment_overflow(&yourtm.tm_sec, 1 - SECSPERMIN))
1915 			return WRONG;
1916 		saved_seconds = yourtm.tm_sec;
1917 		yourtm.tm_sec = SECSPERMIN - 1;
1918 	} else {
1919 		saved_seconds = yourtm.tm_sec;
1920 		yourtm.tm_sec = 0;
1921 	}
1922 	/*
1923 	** Do a binary search (this works whatever time_t's type is).
1924 	*/
1925 	if (!TYPE_SIGNED(time_t)) {
1926 		lo = 0;
1927 		hi = lo - 1;
1928 	} else if (!TYPE_INTEGRAL(time_t)) {
1929 		if (sizeof(time_t) > sizeof(float))
1930 			hi = (time_t) DBL_MAX;
1931 		else	hi = (time_t) FLT_MAX;
1932 		lo = -hi;
1933 	} else {
1934 		lo = 1;
1935 		for (i = 0; i < (int) TYPE_BIT(time_t) - 1; ++i)
1936 			lo *= 2;
1937 		hi = -(lo + 1);
1938 	}
1939 	for ( ; ; ) {
1940 		t = lo / 2 + hi / 2;
1941 		if (t < lo)
1942 			t = lo;
1943 		else if (t > hi)
1944 			t = hi;
1945 		if ((*funcp)(&t, offset, &mytm) == NULL) {
1946 			/*
1947 			** Assume that t is too extreme to be represented in
1948 			** a struct tm; arrange things so that it is less
1949 			** extreme on the next pass.
1950 			*/
1951 			dir = (t > 0) ? 1 : -1;
1952 		} else	dir = tmcomp(&mytm, &yourtm);
1953 		if (dir != 0) {
1954 			if (t == lo) {
1955 				++t;
1956 				if (t <= lo)
1957 					return WRONG;
1958 				++lo;
1959 			} else if (t == hi) {
1960 				--t;
1961 				if (t >= hi)
1962 					return WRONG;
1963 				--hi;
1964 			}
1965 			if (lo > hi)
1966 				return WRONG;
1967 			if (dir > 0)
1968 				hi = t;
1969 			else	lo = t;
1970 			continue;
1971 		}
1972 		if (yourtm.tm_isdst < 0 || mytm.tm_isdst == yourtm.tm_isdst)
1973 			break;
1974 		/*
1975 		** Right time, wrong type.
1976 		** Hunt for right time, right type.
1977 		** It's okay to guess wrong since the guess
1978 		** gets checked.
1979 		*/
1980 		sp = (const struct state *)
1981 			((funcp == localsub) ? lclptr : gmtptr);
1982 #ifdef ALL_STATE
1983 		if (sp == NULL)
1984 			return WRONG;
1985 #endif /* defined ALL_STATE */
1986 		for (i = sp->typecnt - 1; i >= 0; --i) {
1987 			if (sp->ttis[i].tt_isdst != yourtm.tm_isdst)
1988 				continue;
1989 			for (j = sp->typecnt - 1; j >= 0; --j) {
1990 				if (sp->ttis[j].tt_isdst == yourtm.tm_isdst)
1991 					continue;
1992 				newt = t + sp->ttis[j].tt_gmtoff -
1993 					sp->ttis[i].tt_gmtoff;
1994 				if ((*funcp)(&newt, offset, &mytm) == NULL)
1995 					continue;
1996 				if (tmcomp(&mytm, &yourtm) != 0)
1997 					continue;
1998 				if (mytm.tm_isdst != yourtm.tm_isdst)
1999 					continue;
2000 				/*
2001 				** We have a match.
2002 				*/
2003 				t = newt;
2004 				goto label;
2005 			}
2006 		}
2007 		return WRONG;
2008 	}
2009 label:
2010 	newt = t + saved_seconds;
2011 	if ((newt < t) != (saved_seconds < 0))
2012 		return WRONG;
2013 	t = newt;
2014 	if ((*funcp)(&t, offset, tmp))
2015 		*okayp = TRUE;
2016 	return t;
2017 }
2018 
2019 static time_t
time2(struct tm * const tmp,struct tm * (* const funcp)(const time_t *,long,struct tm *),const long offset,int * const okayp)2020 time2(struct tm * const	tmp,
2021       struct tm * (*const funcp)(const time_t *, long, struct tm *),
2022       const long offset,
2023       int *const okayp)
2024 {
2025 	time_t	t;
2026 
2027 	/*
2028 	** First try without normalization of seconds
2029 	** (in case tm_sec contains a value associated with a leap second).
2030 	** If that fails, try with normalization of seconds.
2031 	*/
2032 	t = time2sub(tmp, funcp, offset, okayp, FALSE);
2033 	return *okayp ? t : time2sub(tmp, funcp, offset, okayp, TRUE);
2034 }
2035 
2036 static time_t
time1(tmp,funcp,offset)2037 time1(tmp, funcp, offset)
2038 struct tm * const	tmp;
2039 struct tm * (* const  funcp)(const time_t *, long, struct tm *);
2040 const long		offset;
2041 {
2042 	time_t			t;
2043 	const struct state *	sp;
2044 	int			samei, otheri;
2045 	int			sameind, otherind;
2046 	int			i;
2047 	int			nseen;
2048 	int				seen[TZ_MAX_TYPES];
2049 	int				types[TZ_MAX_TYPES];
2050 	int				okay;
2051 
2052 	if (tmp == NULL) {
2053 		errno = EINVAL;
2054 		return WRONG;
2055 	}
2056 
2057 	if (tmp->tm_isdst > 1)
2058 		tmp->tm_isdst = 1;
2059 	t = time2(tmp, funcp, offset, &okay);
2060 #ifdef PCTS
2061 	/*
2062 	** PCTS code courtesy Grant Sullivan.
2063 	*/
2064 	if (okay)
2065 		return t;
2066 	if (tmp->tm_isdst < 0)
2067 		tmp->tm_isdst = 0;	/* reset to std and try again */
2068 #endif /* defined PCTS */
2069 #ifndef PCTS
2070 	if (okay || tmp->tm_isdst < 0)
2071 		return t;
2072 #endif /* !defined PCTS */
2073 	/*
2074 	** We're supposed to assume that somebody took a time of one type
2075 	** and did some math on it that yielded a "struct tm" that's bad.
2076 	** We try to divine the type they started from and adjust to the
2077 	** type they need.
2078 	*/
2079 	sp = (const struct state *) ((funcp == localsub) ? lclptr : gmtptr);
2080 #ifdef ALL_STATE
2081 	if (sp == NULL)
2082 		return WRONG;
2083 #endif /* defined ALL_STATE */
2084 	for (i = 0; i < sp->typecnt; ++i)
2085 		seen[i] = FALSE;
2086 	nseen = 0;
2087 	for (i = sp->timecnt - 1; i >= 0; --i)
2088 		if (!seen[sp->types[i]]) {
2089 			seen[sp->types[i]] = TRUE;
2090 			types[nseen++] = sp->types[i];
2091 		}
2092 	for (sameind = 0; sameind < nseen; ++sameind) {
2093 		samei = types[sameind];
2094 		if (sp->ttis[samei].tt_isdst != tmp->tm_isdst)
2095 			continue;
2096 		for (otherind = 0; otherind < nseen; ++otherind) {
2097 			otheri = types[otherind];
2098 			if (sp->ttis[otheri].tt_isdst == tmp->tm_isdst)
2099 				continue;
2100 			tmp->tm_sec += sp->ttis[otheri].tt_gmtoff -
2101 					sp->ttis[samei].tt_gmtoff;
2102 			tmp->tm_isdst = !tmp->tm_isdst;
2103 			t = time2(tmp, funcp, offset, &okay);
2104 			if (okay)
2105 				return t;
2106 			tmp->tm_sec -= sp->ttis[otheri].tt_gmtoff -
2107 					sp->ttis[samei].tt_gmtoff;
2108 			tmp->tm_isdst = !tmp->tm_isdst;
2109 		}
2110 	}
2111 	return WRONG;
2112 }
2113 
2114 time_t
mktime(struct tm * const tmp)2115 mktime(struct tm *const tmp)
2116 {
2117 	time_t mktime_return_value;
2118 	_RWLOCK_RDLOCK(&lcl_rwlock);
2119 	tzset_basic(1);
2120 	mktime_return_value = time1(tmp, localsub, 0L);
2121 	_RWLOCK_UNLOCK(&lcl_rwlock);
2122 	return(mktime_return_value);
2123 }
2124 
2125 #ifdef STD_INSPIRED
2126 
2127 time_t
timelocal(struct tm * const tmp)2128 timelocal(struct tm *const tmp)
2129 {
2130 	if (tmp != NULL)
2131 		tmp->tm_isdst = -1;	/* in case it wasn't initialized */
2132 	return mktime(tmp);
2133 }
2134 
2135 time_t
timegm(struct tm * const tmp)2136 timegm(struct tm *const tmp)
2137 {
2138 	if (tmp != NULL)
2139 		tmp->tm_isdst = 0;
2140 	return time1(tmp, gmtsub, 0L);
2141 }
2142 
2143 time_t
timeoff(struct tm * const tmp,const long offset)2144 timeoff(struct tm *const tmp, const long offset)
2145 {
2146 	if (tmp != NULL)
2147 		tmp->tm_isdst = 0;
2148 	return time1(tmp, gmtsub, offset);
2149 }
2150 
2151 #endif /* defined STD_INSPIRED */
2152 
2153 #ifdef CMUCS
2154 
2155 /*
2156 ** The following is supplied for compatibility with
2157 ** previous versions of the CMUCS runtime library.
2158 */
2159 
2160 long
gtime(struct tm * const tmp)2161 gtime(struct tm *const tmp)
2162 {
2163 	const time_t	t = mktime(tmp);
2164 
2165 	if (t == WRONG)
2166 		return -1;
2167 	return t;
2168 }
2169 
2170 #endif /* defined CMUCS */
2171 
2172 /*
2173 ** XXX--is the below the right way to conditionalize??
2174 */
2175 
2176 #ifdef STD_INSPIRED
2177 
2178 /*
2179 ** IEEE Std 1003.1-1988 (POSIX) legislates that 536457599
2180 ** shall correspond to "Wed Dec 31 23:59:59 UTC 1986", which
2181 ** is not the case if we are accounting for leap seconds.
2182 ** So, we provide the following conversion routines for use
2183 ** when exchanging timestamps with POSIX conforming systems.
2184 */
2185 
2186 static long
leapcorr(time_t * timep)2187 leapcorr(time_t *timep)
2188 {
2189 	struct state *		sp;
2190 	struct lsinfo *	lp;
2191 	int			i;
2192 
2193 	sp = lclptr;
2194 	i = sp->leapcnt;
2195 	while (--i >= 0) {
2196 		lp = &sp->lsis[i];
2197 		if (*timep >= lp->ls_trans)
2198 			return lp->ls_corr;
2199 	}
2200 	return 0;
2201 }
2202 
2203 time_t
time2posix(time_t t)2204 time2posix(time_t t)
2205 {
2206 	tzset();
2207 	return t - leapcorr(&t);
2208 }
2209 
2210 time_t
posix2time(time_t t)2211 posix2time(time_t t)
2212 {
2213 	time_t	x;
2214 	time_t	y;
2215 
2216 	tzset();
2217 	/*
2218 	** For a positive leap second hit, the result
2219 	** is not unique. For a negative leap second
2220 	** hit, the corresponding time doesn't exist,
2221 	** so we return an adjacent second.
2222 	*/
2223 	x = t + leapcorr(&t);
2224 	y = x - leapcorr(&x);
2225 	if (y < t) {
2226 		do {
2227 			x++;
2228 			y = x - leapcorr(&x);
2229 		} while (y < t);
2230 		if (t != y)
2231 			return x - 1;
2232 	} else if (y > t) {
2233 		do {
2234 			--x;
2235 			y = x - leapcorr(&x);
2236 		} while (y > t);
2237 		if (t != y)
2238 			return x + 1;
2239 	}
2240 	return x;
2241 }
2242 
2243 #endif /* defined STD_INSPIRED */
2244