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