1 /*
2 ** This file is in the public domain, so clarified as of
3 ** 1996-06-05 by Arthur David Olson.
4 */
5
6 /*
7 ** Leap second handling from Bradley White.
8 ** POSIX-style TZ environment variable handling from Guy Harris.
9 */
10
11 /*LINTLIBRARY*/
12
13 #define LOCALTIME_IMPLEMENTATION
14 #include "private.h"
15
16 #include "tzfile.h"
17 #include "fcntl.h"
18
19 #if THREAD_SAFE
20 # include <pthread.h>
21 static pthread_mutex_t locallock = PTHREAD_MUTEX_INITIALIZER;
lock(void)22 static int lock(void) { return pthread_mutex_lock(&locallock); }
unlock(void)23 static void unlock(void) { pthread_mutex_unlock(&locallock); }
24 #else
lock(void)25 static int lock(void) { return 0; }
unlock(void)26 static void unlock(void) { }
27 #endif
28
29 /* NETBSD_INSPIRED_EXTERN functions are exported to callers if
30 NETBSD_INSPIRED is defined, and are private otherwise. */
31 #if NETBSD_INSPIRED
32 # define NETBSD_INSPIRED_EXTERN
33 #else
34 # define NETBSD_INSPIRED_EXTERN static
35 #endif
36
37 #ifndef TZ_ABBR_MAX_LEN
38 #define TZ_ABBR_MAX_LEN 16
39 #endif /* !defined TZ_ABBR_MAX_LEN */
40
41 #ifndef TZ_ABBR_CHAR_SET
42 #define TZ_ABBR_CHAR_SET \
43 "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789 :+-._"
44 #endif /* !defined TZ_ABBR_CHAR_SET */
45
46 #ifndef TZ_ABBR_ERR_CHAR
47 #define TZ_ABBR_ERR_CHAR '_'
48 #endif /* !defined TZ_ABBR_ERR_CHAR */
49
50 /*
51 ** SunOS 4.1.1 headers lack O_BINARY.
52 */
53
54 #ifdef O_BINARY
55 #define OPEN_MODE (O_RDONLY | O_BINARY)
56 #endif /* defined O_BINARY */
57 #ifndef O_BINARY
58 #define OPEN_MODE O_RDONLY
59 #endif /* !defined O_BINARY */
60
61 #ifndef WILDABBR
62 /*
63 ** Someone might make incorrect use of a time zone abbreviation:
64 ** 1. They might reference tzname[0] before calling tzset (explicitly
65 ** or implicitly).
66 ** 2. They might reference tzname[1] before calling tzset (explicitly
67 ** or implicitly).
68 ** 3. They might reference tzname[1] after setting to a time zone
69 ** in which Daylight Saving Time is never observed.
70 ** 4. They might reference tzname[0] after setting to a time zone
71 ** in which Standard Time is never observed.
72 ** 5. They might reference tm.TM_ZONE after calling offtime.
73 ** What's best to do in the above cases is open to debate;
74 ** for now, we just set things up so that in any of the five cases
75 ** WILDABBR is used. Another possibility: initialize tzname[0] to the
76 ** string "tzname[0] used before set", and similarly for the other cases.
77 ** And another: initialize tzname[0] to "ERA", with an explanation in the
78 ** manual page of what this "time zone abbreviation" means (doing this so
79 ** that tzname[0] has the "normal" length of three characters).
80 */
81 #define WILDABBR " "
82 #endif /* !defined WILDABBR */
83
84 static const char wildabbr[] = WILDABBR;
85
86 static const char gmt[] = "GMT";
87
88 /*
89 ** The DST rules to use if TZ has no rules and we can't load TZDEFRULES.
90 ** We default to US rules as of 1999-08-17.
91 ** POSIX 1003.1 section 8.1.1 says that the default DST rules are
92 ** implementation dependent; for historical reasons, US rules are a
93 ** common default.
94 */
95 #ifndef TZDEFRULESTRING
96 #define TZDEFRULESTRING ",M4.1.0,M10.5.0"
97 #endif /* !defined TZDEFDST */
98
99 struct ttinfo { /* time type information */
100 int_fast32_t tt_gmtoff; /* UT offset in seconds */
101 bool tt_isdst; /* used to set tm_isdst */
102 int tt_abbrind; /* abbreviation list index */
103 bool tt_ttisstd; /* transition is std time */
104 bool tt_ttisgmt; /* transition is UT */
105 };
106
107 struct lsinfo { /* leap second information */
108 time_t ls_trans; /* transition time */
109 int_fast64_t ls_corr; /* correction to apply */
110 };
111
112 #define SMALLEST(a, b) (((a) < (b)) ? (a) : (b))
113 #define BIGGEST(a, b) (((a) > (b)) ? (a) : (b))
114
115 #ifdef TZNAME_MAX
116 #define MY_TZNAME_MAX TZNAME_MAX
117 #endif /* defined TZNAME_MAX */
118 #ifndef TZNAME_MAX
119 #define MY_TZNAME_MAX 255
120 #endif /* !defined TZNAME_MAX */
121
122 struct state {
123 int leapcnt;
124 int timecnt;
125 int typecnt;
126 int charcnt;
127 bool goback;
128 bool goahead;
129 time_t ats[TZ_MAX_TIMES];
130 unsigned char types[TZ_MAX_TIMES];
131 struct ttinfo ttis[TZ_MAX_TYPES];
132 char chars[BIGGEST(BIGGEST(TZ_MAX_CHARS + 1, sizeof gmt),
133 (2 * (MY_TZNAME_MAX + 1)))];
134 struct lsinfo lsis[TZ_MAX_LEAPS];
135 int defaulttype; /* for early times or if no transitions */
136 };
137
138 enum r_type {
139 JULIAN_DAY, /* Jn = Julian day */
140 DAY_OF_YEAR, /* n = day of year */
141 MONTH_NTH_DAY_OF_WEEK /* Mm.n.d = month, week, day of week */
142 };
143
144 struct rule {
145 enum r_type r_type; /* type of rule */
146 int r_day; /* day number of rule */
147 int r_week; /* week number of rule */
148 int r_mon; /* month number of rule */
149 int_fast32_t r_time; /* transition time of rule */
150 };
151
152 static struct tm *gmtsub(struct state const *, time_t const *, int_fast32_t,
153 struct tm *);
154 static bool increment_overflow(int *, int);
155 static bool increment_overflow_time(time_t *, int_fast32_t);
156 static bool normalize_overflow32(int_fast32_t *, int *, int);
157 static struct tm *timesub(time_t const *, int_fast32_t, struct state const *,
158 struct tm *);
159 static bool typesequiv(struct state const *, int, int);
160 static bool tzparse(char const *, struct state *, bool);
161
162 #ifdef ALL_STATE
163 static struct state * lclptr;
164 static struct state * gmtptr;
165 #endif /* defined ALL_STATE */
166
167 #ifndef ALL_STATE
168 static struct state lclmem;
169 static struct state gmtmem;
170 #define lclptr (&lclmem)
171 #define gmtptr (&gmtmem)
172 #endif /* State Farm */
173
174 #ifndef TZ_STRLEN_MAX
175 #define TZ_STRLEN_MAX 255
176 #endif /* !defined TZ_STRLEN_MAX */
177
178 static char lcl_TZname[TZ_STRLEN_MAX + 1];
179 static int lcl_is_set;
180
181 char * tzname[2] = {
182 (char *) wildabbr,
183 (char *) wildabbr
184 };
185
186 /*
187 ** Section 4.12.3 of X3.159-1989 requires that
188 ** Except for the strftime function, these functions [asctime,
189 ** ctime, gmtime, localtime] return values in one of two static
190 ** objects: a broken-down time structure and an array of char.
191 ** Thanks to Paul Eggert for noting this.
192 */
193
194 static struct tm tm;
195
196 #ifdef USG_COMPAT
197 long timezone;
198 int daylight;
199 #endif /* defined USG_COMPAT */
200
201 #ifdef ALTZONE
202 long altzone;
203 #endif /* defined ALTZONE */
204
205 /* Initialize *S to a value based on GMTOFF, ISDST, and ABBRIND. */
206 static void
init_ttinfo(struct ttinfo * s,int_fast32_t gmtoff,bool isdst,int abbrind)207 init_ttinfo(struct ttinfo *s, int_fast32_t gmtoff, bool isdst, int abbrind)
208 {
209 s->tt_gmtoff = gmtoff;
210 s->tt_isdst = isdst;
211 s->tt_abbrind = abbrind;
212 s->tt_ttisstd = false;
213 s->tt_ttisgmt = false;
214 }
215
216 static int_fast32_t
detzcode(const char * const codep)217 detzcode(const char *const codep)
218 {
219 register int_fast32_t result;
220 register int i;
221 int_fast32_t one = 1;
222 int_fast32_t halfmaxval = one << (32 - 2);
223 int_fast32_t maxval = halfmaxval - 1 + halfmaxval;
224 int_fast32_t minval = -1 - maxval;
225
226 result = codep[0] & 0x7f;
227 for (i = 1; i < 4; ++i)
228 result = (result << 8) | (codep[i] & 0xff);
229
230 if (codep[0] & 0x80) {
231 /* Do two's-complement negation even on non-two's-complement machines.
232 If the result would be minval - 1, return minval. */
233 result -= !TWOS_COMPLEMENT(int_fast32_t) && result != 0;
234 result += minval;
235 }
236 return result;
237 }
238
239 static int_fast64_t
detzcode64(const char * const codep)240 detzcode64(const char *const codep)
241 {
242 register uint_fast64_t result;
243 register int i;
244 int_fast64_t one = 1;
245 int_fast64_t halfmaxval = one << (64 - 2);
246 int_fast64_t maxval = halfmaxval - 1 + halfmaxval;
247 int_fast64_t minval = -TWOS_COMPLEMENT(int_fast64_t) - maxval;
248
249 result = codep[0] & 0x7f;
250 for (i = 1; i < 8; ++i)
251 result = (result << 8) | (codep[i] & 0xff);
252
253 if (codep[0] & 0x80) {
254 /* Do two's-complement negation even on non-two's-complement machines.
255 If the result would be minval - 1, return minval. */
256 result -= !TWOS_COMPLEMENT(int_fast64_t) && result != 0;
257 result += minval;
258 }
259 return result;
260 }
261
262 static void
update_tzname_etc(struct state const * sp,struct ttinfo const * ttisp)263 update_tzname_etc(struct state const *sp, struct ttinfo const *ttisp)
264 {
265 tzname[ttisp->tt_isdst] = (char *) &sp->chars[ttisp->tt_abbrind];
266 #ifdef USG_COMPAT
267 if (!ttisp->tt_isdst)
268 timezone = - ttisp->tt_gmtoff;
269 #endif
270 #ifdef ALTZONE
271 if (ttisp->tt_isdst)
272 altzone = - ttisp->tt_gmtoff;
273 #endif
274 }
275
276 static void
settzname(void)277 settzname(void)
278 {
279 register struct state * const sp = lclptr;
280 register int i;
281
282 tzname[0] = tzname[1] = (char *) wildabbr;
283 #ifdef USG_COMPAT
284 daylight = 0;
285 timezone = 0;
286 #endif /* defined USG_COMPAT */
287 #ifdef ALTZONE
288 altzone = 0;
289 #endif /* defined ALTZONE */
290 if (sp == NULL) {
291 tzname[0] = tzname[1] = (char *) gmt;
292 return;
293 }
294 /*
295 ** And to get the latest zone names into tzname. . .
296 */
297 for (i = 0; i < sp->typecnt; ++i) {
298 register const struct ttinfo * const ttisp = &sp->ttis[i];
299 update_tzname_etc(sp, ttisp);
300 }
301 for (i = 0; i < sp->timecnt; ++i) {
302 register const struct ttinfo * const ttisp =
303 &sp->ttis[
304 sp->types[i]];
305 update_tzname_etc(sp, ttisp);
306 #ifdef USG_COMPAT
307 if (ttisp->tt_isdst)
308 daylight = 1;
309 #endif /* defined USG_COMPAT */
310 }
311 }
312
313 static void
scrub_abbrs(struct state * sp)314 scrub_abbrs(struct state *sp)
315 {
316 int i;
317 /*
318 ** First, replace bogus characters.
319 */
320 for (i = 0; i < sp->charcnt; ++i)
321 if (strchr(TZ_ABBR_CHAR_SET, sp->chars[i]) == NULL)
322 sp->chars[i] = TZ_ABBR_ERR_CHAR;
323 /*
324 ** Second, truncate long abbreviations.
325 */
326 for (i = 0; i < sp->typecnt; ++i) {
327 register const struct ttinfo * const ttisp = &sp->ttis[i];
328 register char * cp = &sp->chars[ttisp->tt_abbrind];
329
330 if (strlen(cp) > TZ_ABBR_MAX_LEN &&
331 strcmp(cp, GRANDPARENTED) != 0)
332 *(cp + TZ_ABBR_MAX_LEN) = '\0';
333 }
334 }
335
336 static bool
differ_by_repeat(const time_t t1,const time_t t0)337 differ_by_repeat(const time_t t1, const time_t t0)
338 {
339 if (TYPE_BIT(time_t) - TYPE_SIGNED(time_t) < SECSPERREPEAT_BITS)
340 return 0;
341 #if defined(__LP64__) // 32-bit Android/glibc has a signed 32-bit time_t; 64-bit doesn't.
342 return t1 - t0 == SECSPERREPEAT;
343 #endif
344 }
345
346 /* Input buffer for data read from a compiled tz file. */
347 union input_buffer {
348 /* The first part of the buffer, interpreted as a header. */
349 struct tzhead tzhead;
350
351 /* The entire buffer. */
352 char buf[2 * sizeof(struct tzhead) + 2 * sizeof (struct state)
353 + 4 * TZ_MAX_TIMES];
354 };
355
356 /* Local storage needed for 'tzloadbody'. */
357 union local_storage {
358 /* The file name to be opened. */
359 char fullname[FILENAME_MAX + 1];
360
361 /* The results of analyzing the file's contents after it is opened. */
362 struct {
363 /* The input buffer. */
364 union input_buffer u;
365
366 /* A temporary state used for parsing a TZ string in the file. */
367 struct state st;
368 } u;
369 };
370
371 static int __bionic_open_tzdata(const char*);
372
373 /* Load tz data from the file named NAME into *SP. Read extended
374 format if DOEXTEND. Use *LSP for temporary storage. Return 0 on
375 success, an errno value on failure. */
376 static int
tzloadbody(char const * name,struct state * sp,bool doextend,union local_storage * lsp)377 tzloadbody(char const *name, struct state *sp, bool doextend,
378 union local_storage *lsp)
379 {
380 register int i;
381 register int fid;
382 register int stored;
383 register ssize_t nread;
384 #if !defined(__ANDROID__)
385 register bool doaccess;
386 register char *fullname = lsp->fullname;
387 #endif
388 register union input_buffer *up = &lsp->u.u;
389 register int tzheadsize = sizeof (struct tzhead);
390
391 sp->goback = sp->goahead = false;
392
393 if (! name) {
394 name = TZDEFAULT;
395 if (! name)
396 return EINVAL;
397 }
398
399 #if defined(__ANDROID__)
400 fid = __bionic_open_tzdata(name);
401 #else
402 if (name[0] == ':')
403 ++name;
404 doaccess = name[0] == '/';
405 if (!doaccess) {
406 char const *p = TZDIR;
407 if (! p)
408 return EINVAL;
409 if (sizeof lsp->fullname - 1 <= strlen(p) + strlen(name))
410 return ENAMETOOLONG;
411 strcpy(fullname, p);
412 strcat(fullname, "/");
413 strcat(fullname, name);
414 /* Set doaccess if '.' (as in "../") shows up in name. */
415 if (strchr(name, '.'))
416 doaccess = true;
417 name = fullname;
418 }
419 if (doaccess && access(name, R_OK) != 0)
420 return errno;
421 fid = open(name, OPEN_MODE);
422 #endif
423 if (fid < 0)
424 return errno;
425
426 nread = read(fid, up->buf, sizeof up->buf);
427 if (nread < tzheadsize) {
428 int err = nread < 0 ? errno : EINVAL;
429 close(fid);
430 return err;
431 }
432 if (close(fid) < 0)
433 return errno;
434 for (stored = 4; stored <= 8; stored *= 2) {
435 int_fast32_t ttisstdcnt = detzcode(up->tzhead.tzh_ttisstdcnt);
436 int_fast32_t ttisgmtcnt = detzcode(up->tzhead.tzh_ttisgmtcnt);
437 int_fast32_t leapcnt = detzcode(up->tzhead.tzh_leapcnt);
438 int_fast32_t timecnt = detzcode(up->tzhead.tzh_timecnt);
439 int_fast32_t typecnt = detzcode(up->tzhead.tzh_typecnt);
440 int_fast32_t charcnt = detzcode(up->tzhead.tzh_charcnt);
441 char const *p = up->buf + tzheadsize;
442 if (! (0 <= leapcnt && leapcnt < TZ_MAX_LEAPS
443 && 0 < typecnt && typecnt < TZ_MAX_TYPES
444 && 0 <= timecnt && timecnt < TZ_MAX_TIMES
445 && 0 <= charcnt && charcnt < TZ_MAX_CHARS
446 && (ttisstdcnt == typecnt || ttisstdcnt == 0)
447 && (ttisgmtcnt == typecnt || ttisgmtcnt == 0)))
448 return EINVAL;
449 if (nread
450 < (tzheadsize /* struct tzhead */
451 + timecnt * stored /* ats */
452 + timecnt /* types */
453 + typecnt * 6 /* ttinfos */
454 + charcnt /* chars */
455 + leapcnt * (stored + 4) /* lsinfos */
456 + ttisstdcnt /* ttisstds */
457 + ttisgmtcnt)) /* ttisgmts */
458 return EINVAL;
459 sp->leapcnt = leapcnt;
460 sp->timecnt = timecnt;
461 sp->typecnt = typecnt;
462 sp->charcnt = charcnt;
463
464 /* Read transitions, discarding those out of time_t range.
465 But pretend the last transition before time_t_min
466 occurred at time_t_min. */
467 timecnt = 0;
468 for (i = 0; i < sp->timecnt; ++i) {
469 int_fast64_t at
470 = stored == 4 ? detzcode(p) : detzcode64(p);
471 sp->types[i] = at <= time_t_max;
472 if (sp->types[i]) {
473 time_t attime
474 = ((TYPE_SIGNED(time_t) ? at < time_t_min : at < 0)
475 ? time_t_min : at);
476 if (timecnt && attime <= sp->ats[timecnt - 1]) {
477 if (attime < sp->ats[timecnt - 1])
478 return EINVAL;
479 sp->types[i - 1] = 0;
480 timecnt--;
481 }
482 sp->ats[timecnt++] = attime;
483 }
484 p += stored;
485 }
486
487 timecnt = 0;
488 for (i = 0; i < sp->timecnt; ++i) {
489 unsigned char typ = *p++;
490 if (sp->typecnt <= typ)
491 return EINVAL;
492 if (sp->types[i])
493 sp->types[timecnt++] = typ;
494 }
495 sp->timecnt = timecnt;
496 for (i = 0; i < sp->typecnt; ++i) {
497 register struct ttinfo * ttisp;
498 unsigned char isdst, abbrind;
499
500 ttisp = &sp->ttis[i];
501 ttisp->tt_gmtoff = detzcode(p);
502 p += 4;
503 isdst = *p++;
504 if (! (isdst < 2))
505 return EINVAL;
506 ttisp->tt_isdst = isdst;
507 abbrind = *p++;
508 if (! (abbrind < sp->charcnt))
509 return EINVAL;
510 ttisp->tt_abbrind = abbrind;
511 }
512 for (i = 0; i < sp->charcnt; ++i)
513 sp->chars[i] = *p++;
514 sp->chars[i] = '\0'; /* ensure '\0' at end */
515
516 /* Read leap seconds, discarding those out of time_t range. */
517 leapcnt = 0;
518 for (i = 0; i < sp->leapcnt; ++i) {
519 int_fast64_t tr = stored == 4 ? detzcode(p) : detzcode64(p);
520 int_fast32_t corr = detzcode(p + stored);
521 p += stored + 4;
522 if (tr <= time_t_max) {
523 time_t trans
524 = ((TYPE_SIGNED(time_t) ? tr < time_t_min : tr < 0)
525 ? time_t_min : tr);
526 if (leapcnt && trans <= sp->lsis[leapcnt - 1].ls_trans) {
527 if (trans < sp->lsis[leapcnt - 1].ls_trans)
528 return EINVAL;
529 leapcnt--;
530 }
531 sp->lsis[leapcnt].ls_trans = trans;
532 sp->lsis[leapcnt].ls_corr = corr;
533 leapcnt++;
534 }
535 }
536 sp->leapcnt = leapcnt;
537
538 for (i = 0; i < sp->typecnt; ++i) {
539 register struct ttinfo * ttisp;
540
541 ttisp = &sp->ttis[i];
542 if (ttisstdcnt == 0)
543 ttisp->tt_ttisstd = false;
544 else {
545 if (*p != true && *p != false)
546 return EINVAL;
547 ttisp->tt_ttisstd = *p++;
548 }
549 }
550 for (i = 0; i < sp->typecnt; ++i) {
551 register struct ttinfo * ttisp;
552
553 ttisp = &sp->ttis[i];
554 if (ttisgmtcnt == 0)
555 ttisp->tt_ttisgmt = false;
556 else {
557 if (*p != true && *p != false)
558 return EINVAL;
559 ttisp->tt_ttisgmt = *p++;
560 }
561 }
562 /*
563 ** If this is an old file, we're done.
564 */
565 if (up->tzhead.tzh_version[0] == '\0')
566 break;
567 nread -= p - up->buf;
568 memmove(up->buf, p, nread);
569 }
570 if (doextend && nread > 2 &&
571 up->buf[0] == '\n' && up->buf[nread - 1] == '\n' &&
572 sp->typecnt + 2 <= TZ_MAX_TYPES) {
573 struct state *ts = &lsp->u.st;
574
575 up->buf[nread - 1] = '\0';
576 if (tzparse(&up->buf[1], ts, false)
577 && ts->typecnt == 2) {
578
579 /* Attempt to reuse existing abbreviations.
580 Without this, America/Anchorage would stop
581 working after 2037 when TZ_MAX_CHARS is 50, as
582 sp->charcnt equals 42 (for LMT CAT CAWT CAPT AHST
583 AHDT YST AKDT AKST) and ts->charcnt equals 10
584 (for AKST AKDT). Reusing means sp->charcnt can
585 stay 42 in this example. */
586 int gotabbr = 0;
587 int charcnt = sp->charcnt;
588 for (i = 0; i < 2; i++) {
589 char *tsabbr = ts->chars + ts->ttis[i].tt_abbrind;
590 int j;
591 for (j = 0; j < charcnt; j++)
592 if (strcmp(sp->chars + j, tsabbr) == 0) {
593 ts->ttis[i].tt_abbrind = j;
594 gotabbr++;
595 break;
596 }
597 if (! (j < charcnt)) {
598 int tsabbrlen = strlen(tsabbr);
599 if (j + tsabbrlen < TZ_MAX_CHARS) {
600 strcpy(sp->chars + j, tsabbr);
601 charcnt = j + tsabbrlen + 1;
602 ts->ttis[i].tt_abbrind = j;
603 gotabbr++;
604 }
605 }
606 }
607 if (gotabbr == 2) {
608 sp->charcnt = charcnt;
609 for (i = 0; i < ts->timecnt; i++)
610 if (sp->ats[sp->timecnt - 1] < ts->ats[i])
611 break;
612 while (i < ts->timecnt
613 && sp->timecnt < TZ_MAX_TIMES) {
614 sp->ats[sp->timecnt] = ts->ats[i];
615 sp->types[sp->timecnt] = (sp->typecnt
616 + ts->types[i]);
617 sp->timecnt++;
618 i++;
619 }
620 sp->ttis[sp->typecnt++] = ts->ttis[0];
621 sp->ttis[sp->typecnt++] = ts->ttis[1];
622 }
623 }
624 }
625 if (sp->timecnt > 1) {
626 for (i = 1; i < sp->timecnt; ++i)
627 if (typesequiv(sp, sp->types[i], sp->types[0]) &&
628 differ_by_repeat(sp->ats[i], sp->ats[0])) {
629 sp->goback = true;
630 break;
631 }
632 for (i = sp->timecnt - 2; i >= 0; --i)
633 if (typesequiv(sp, sp->types[sp->timecnt - 1],
634 sp->types[i]) &&
635 differ_by_repeat(sp->ats[sp->timecnt - 1],
636 sp->ats[i])) {
637 sp->goahead = true;
638 break;
639 }
640 }
641 /*
642 ** If type 0 is is unused in transitions,
643 ** it's the type to use for early times.
644 */
645 for (i = 0; i < sp->timecnt; ++i)
646 if (sp->types[i] == 0)
647 break;
648 i = i < sp->timecnt ? -1 : 0;
649 /*
650 ** Absent the above,
651 ** if there are transition times
652 ** and the first transition is to a daylight time
653 ** find the standard type less than and closest to
654 ** the type of the first transition.
655 */
656 if (i < 0 && sp->timecnt > 0 && sp->ttis[sp->types[0]].tt_isdst) {
657 i = sp->types[0];
658 while (--i >= 0)
659 if (!sp->ttis[i].tt_isdst)
660 break;
661 }
662 /*
663 ** If no result yet, find the first standard type.
664 ** If there is none, punt to type zero.
665 */
666 if (i < 0) {
667 i = 0;
668 while (sp->ttis[i].tt_isdst)
669 if (++i >= sp->typecnt) {
670 i = 0;
671 break;
672 }
673 }
674 sp->defaulttype = i;
675 return 0;
676 }
677
678 /* Load tz data from the file named NAME into *SP. Read extended
679 format if DOEXTEND. Return 0 on success, an errno value on failure. */
680 static int
tzload(char const * name,struct state * sp,bool doextend)681 tzload(char const *name, struct state *sp, bool doextend)
682 {
683 #ifdef ALL_STATE
684 union local_storage *lsp = malloc(sizeof *lsp);
685 if (!lsp)
686 return errno;
687 else {
688 int err = tzloadbody(name, sp, doextend, lsp);
689 free(lsp);
690 return err;
691 }
692 #else
693 union local_storage ls;
694 return tzloadbody(name, sp, doextend, &ls);
695 #endif
696 }
697
698 static bool
typesequiv(const struct state * sp,int a,int b)699 typesequiv(const struct state *sp, int a, int b)
700 {
701 register bool result;
702
703 if (sp == NULL ||
704 a < 0 || a >= sp->typecnt ||
705 b < 0 || b >= sp->typecnt)
706 result = false;
707 else {
708 register const struct ttinfo * ap = &sp->ttis[a];
709 register const struct ttinfo * bp = &sp->ttis[b];
710 result = ap->tt_gmtoff == bp->tt_gmtoff &&
711 ap->tt_isdst == bp->tt_isdst &&
712 ap->tt_ttisstd == bp->tt_ttisstd &&
713 ap->tt_ttisgmt == bp->tt_ttisgmt &&
714 strcmp(&sp->chars[ap->tt_abbrind],
715 &sp->chars[bp->tt_abbrind]) == 0;
716 }
717 return result;
718 }
719
720 static const int mon_lengths[2][MONSPERYEAR] = {
721 { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 },
722 { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }
723 };
724
725 static const int year_lengths[2] = {
726 DAYSPERNYEAR, DAYSPERLYEAR
727 };
728
729 /*
730 ** Given a pointer into a time zone string, scan until a character that is not
731 ** a valid character in a zone name is found. Return a pointer to that
732 ** character.
733 */
734
735 static const char * ATTRIBUTE_PURE
getzname(register const char * strp)736 getzname(register const char *strp)
737 {
738 register char c;
739
740 while ((c = *strp) != '\0' && !is_digit(c) && c != ',' && c != '-' &&
741 c != '+')
742 ++strp;
743 return strp;
744 }
745
746 /*
747 ** Given a pointer into an extended time zone string, scan until the ending
748 ** delimiter of the zone name is located. Return a pointer to the delimiter.
749 **
750 ** As with getzname above, the legal character set is actually quite
751 ** restricted, with other characters producing undefined results.
752 ** We don't do any checking here; checking is done later in common-case code.
753 */
754
755 static const char * ATTRIBUTE_PURE
getqzname(register const char * strp,const int delim)756 getqzname(register const char *strp, const int delim)
757 {
758 register int c;
759
760 while ((c = *strp) != '\0' && c != delim)
761 ++strp;
762 return strp;
763 }
764
765 /*
766 ** Given a pointer into a time zone string, extract a number from that string.
767 ** Check that the number is within a specified range; if it is not, return
768 ** NULL.
769 ** Otherwise, return a pointer to the first character not part of the number.
770 */
771
772 static const char *
getnum(register const char * strp,int * const nump,const int min,const int max)773 getnum(register const char *strp, int *const nump, const int min, const int max)
774 {
775 register char c;
776 register int num;
777
778 if (strp == NULL || !is_digit(c = *strp))
779 return NULL;
780 num = 0;
781 do {
782 num = num * 10 + (c - '0');
783 if (num > max)
784 return NULL; /* illegal value */
785 c = *++strp;
786 } while (is_digit(c));
787 if (num < min)
788 return NULL; /* illegal value */
789 *nump = num;
790 return strp;
791 }
792
793 /*
794 ** Given a pointer into a time zone string, extract a number of seconds,
795 ** in hh[:mm[:ss]] form, from the string.
796 ** If any error occurs, return NULL.
797 ** Otherwise, return a pointer to the first character not part of the number
798 ** of seconds.
799 */
800
801 static const char *
getsecs(register const char * strp,int_fast32_t * const secsp)802 getsecs(register const char *strp, int_fast32_t *const secsp)
803 {
804 int num;
805
806 /*
807 ** 'HOURSPERDAY * DAYSPERWEEK - 1' allows quasi-Posix rules like
808 ** "M10.4.6/26", which does not conform to Posix,
809 ** but which specifies the equivalent of
810 ** "02:00 on the first Sunday on or after 23 Oct".
811 */
812 strp = getnum(strp, &num, 0, HOURSPERDAY * DAYSPERWEEK - 1);
813 if (strp == NULL)
814 return NULL;
815 *secsp = num * (int_fast32_t) SECSPERHOUR;
816 if (*strp == ':') {
817 ++strp;
818 strp = getnum(strp, &num, 0, MINSPERHOUR - 1);
819 if (strp == NULL)
820 return NULL;
821 *secsp += num * SECSPERMIN;
822 if (*strp == ':') {
823 ++strp;
824 /* 'SECSPERMIN' allows for leap seconds. */
825 strp = getnum(strp, &num, 0, SECSPERMIN);
826 if (strp == NULL)
827 return NULL;
828 *secsp += num;
829 }
830 }
831 return strp;
832 }
833
834 /*
835 ** Given a pointer into a time zone string, extract an offset, in
836 ** [+-]hh[:mm[:ss]] form, from the string.
837 ** If any error occurs, return NULL.
838 ** Otherwise, return a pointer to the first character not part of the time.
839 */
840
841 static const char *
getoffset(register const char * strp,int_fast32_t * const offsetp)842 getoffset(register const char *strp, int_fast32_t *const offsetp)
843 {
844 register bool neg = false;
845
846 if (*strp == '-') {
847 neg = true;
848 ++strp;
849 } else if (*strp == '+')
850 ++strp;
851 strp = getsecs(strp, offsetp);
852 if (strp == NULL)
853 return NULL; /* illegal time */
854 if (neg)
855 *offsetp = -*offsetp;
856 return strp;
857 }
858
859 /*
860 ** Given a pointer into a time zone string, extract a rule in the form
861 ** date[/time]. See POSIX section 8 for the format of "date" and "time".
862 ** If a valid rule is not found, return NULL.
863 ** Otherwise, return a pointer to the first character not part of the rule.
864 */
865
866 static const char *
getrule(const char * strp,register struct rule * const rulep)867 getrule(const char *strp, register struct rule *const rulep)
868 {
869 if (*strp == 'J') {
870 /*
871 ** Julian day.
872 */
873 rulep->r_type = JULIAN_DAY;
874 ++strp;
875 strp = getnum(strp, &rulep->r_day, 1, DAYSPERNYEAR);
876 } else if (*strp == 'M') {
877 /*
878 ** Month, week, day.
879 */
880 rulep->r_type = MONTH_NTH_DAY_OF_WEEK;
881 ++strp;
882 strp = getnum(strp, &rulep->r_mon, 1, MONSPERYEAR);
883 if (strp == NULL)
884 return NULL;
885 if (*strp++ != '.')
886 return NULL;
887 strp = getnum(strp, &rulep->r_week, 1, 5);
888 if (strp == NULL)
889 return NULL;
890 if (*strp++ != '.')
891 return NULL;
892 strp = getnum(strp, &rulep->r_day, 0, DAYSPERWEEK - 1);
893 } else if (is_digit(*strp)) {
894 /*
895 ** Day of year.
896 */
897 rulep->r_type = DAY_OF_YEAR;
898 strp = getnum(strp, &rulep->r_day, 0, DAYSPERLYEAR - 1);
899 } else return NULL; /* invalid format */
900 if (strp == NULL)
901 return NULL;
902 if (*strp == '/') {
903 /*
904 ** Time specified.
905 */
906 ++strp;
907 strp = getoffset(strp, &rulep->r_time);
908 } else rulep->r_time = 2 * SECSPERHOUR; /* default = 2:00:00 */
909 return strp;
910 }
911
912 /*
913 ** Given a year, a rule, and the offset from UT at the time that rule takes
914 ** effect, calculate the year-relative time that rule takes effect.
915 */
916
917 static int_fast32_t ATTRIBUTE_PURE
transtime(const int year,register const struct rule * const rulep,const int_fast32_t offset)918 transtime(const int year, register const struct rule *const rulep,
919 const int_fast32_t offset)
920 {
921 register bool leapyear;
922 register int_fast32_t value;
923 register int i;
924 int d, m1, yy0, yy1, yy2, dow;
925
926 INITIALIZE(value);
927 leapyear = isleap(year);
928 switch (rulep->r_type) {
929
930 case JULIAN_DAY:
931 /*
932 ** Jn - Julian day, 1 == January 1, 60 == March 1 even in leap
933 ** years.
934 ** In non-leap years, or if the day number is 59 or less, just
935 ** add SECSPERDAY times the day number-1 to the time of
936 ** January 1, midnight, to get the day.
937 */
938 value = (rulep->r_day - 1) * SECSPERDAY;
939 if (leapyear && rulep->r_day >= 60)
940 value += SECSPERDAY;
941 break;
942
943 case DAY_OF_YEAR:
944 /*
945 ** n - day of year.
946 ** Just add SECSPERDAY times the day number to the time of
947 ** January 1, midnight, to get the day.
948 */
949 value = rulep->r_day * SECSPERDAY;
950 break;
951
952 case MONTH_NTH_DAY_OF_WEEK:
953 /*
954 ** Mm.n.d - nth "dth day" of month m.
955 */
956
957 /*
958 ** Use Zeller's Congruence to get day-of-week of first day of
959 ** month.
960 */
961 m1 = (rulep->r_mon + 9) % 12 + 1;
962 yy0 = (rulep->r_mon <= 2) ? (year - 1) : year;
963 yy1 = yy0 / 100;
964 yy2 = yy0 % 100;
965 dow = ((26 * m1 - 2) / 10 +
966 1 + yy2 + yy2 / 4 + yy1 / 4 - 2 * yy1) % 7;
967 if (dow < 0)
968 dow += DAYSPERWEEK;
969
970 /*
971 ** "dow" is the day-of-week of the first day of the month. Get
972 ** the day-of-month (zero-origin) of the first "dow" day of the
973 ** month.
974 */
975 d = rulep->r_day - dow;
976 if (d < 0)
977 d += DAYSPERWEEK;
978 for (i = 1; i < rulep->r_week; ++i) {
979 if (d + DAYSPERWEEK >=
980 mon_lengths[leapyear][rulep->r_mon - 1])
981 break;
982 d += DAYSPERWEEK;
983 }
984
985 /*
986 ** "d" is the day-of-month (zero-origin) of the day we want.
987 */
988 value = d * SECSPERDAY;
989 for (i = 0; i < rulep->r_mon - 1; ++i)
990 value += mon_lengths[leapyear][i] * SECSPERDAY;
991 break;
992 }
993
994 /*
995 ** "value" is the year-relative time of 00:00:00 UT on the day in
996 ** question. To get the year-relative time of the specified local
997 ** time on that day, add the transition time and the current offset
998 ** from UT.
999 */
1000 return value + rulep->r_time + offset;
1001 }
1002
1003 /*
1004 ** Given a POSIX section 8-style TZ string, fill in the rule tables as
1005 ** appropriate.
1006 */
1007
1008 static bool
tzparse(const char * name,struct state * sp,bool lastditch)1009 tzparse(const char *name, struct state *sp, bool lastditch)
1010 {
1011 const char * stdname;
1012 const char * dstname;
1013 size_t stdlen;
1014 size_t dstlen;
1015 size_t charcnt;
1016 int_fast32_t stdoffset;
1017 int_fast32_t dstoffset;
1018 register char * cp;
1019 register bool load_ok;
1020
1021 stdname = name;
1022 if (lastditch) {
1023 stdlen = sizeof gmt - 1;
1024 name += stdlen;
1025 stdoffset = 0;
1026 } else {
1027 if (*name == '<') {
1028 name++;
1029 stdname = name;
1030 name = getqzname(name, '>');
1031 if (*name != '>')
1032 return false;
1033 stdlen = name - stdname;
1034 name++;
1035 } else {
1036 name = getzname(name);
1037 stdlen = name - stdname;
1038 }
1039 if (!stdlen)
1040 return false;
1041 name = getoffset(name, &stdoffset);
1042 if (name == NULL)
1043 return false;
1044 }
1045 charcnt = stdlen + 1;
1046 if (sizeof sp->chars < charcnt)
1047 return false;
1048 load_ok = tzload(TZDEFRULES, sp, false) == 0;
1049 if (!load_ok)
1050 sp->leapcnt = 0; /* so, we're off a little */
1051 if (*name != '\0') {
1052 if (*name == '<') {
1053 dstname = ++name;
1054 name = getqzname(name, '>');
1055 if (*name != '>')
1056 return false;
1057 dstlen = name - dstname;
1058 name++;
1059 } else {
1060 dstname = name;
1061 name = getzname(name);
1062 dstlen = name - dstname; /* length of DST zone name */
1063 }
1064 if (!dstlen)
1065 return false;
1066 charcnt += dstlen + 1;
1067 if (sizeof sp->chars < charcnt)
1068 return false;
1069 if (*name != '\0' && *name != ',' && *name != ';') {
1070 name = getoffset(name, &dstoffset);
1071 if (name == NULL)
1072 return false;
1073 } else dstoffset = stdoffset - SECSPERHOUR;
1074 if (*name == '\0' && !load_ok)
1075 name = TZDEFRULESTRING;
1076 if (*name == ',' || *name == ';') {
1077 struct rule start;
1078 struct rule end;
1079 register int year;
1080 register int yearlim;
1081 register int timecnt;
1082 time_t janfirst;
1083
1084 ++name;
1085 if ((name = getrule(name, &start)) == NULL)
1086 return false;
1087 if (*name++ != ',')
1088 return false;
1089 if ((name = getrule(name, &end)) == NULL)
1090 return false;
1091 if (*name != '\0')
1092 return false;
1093 sp->typecnt = 2; /* standard time and DST */
1094 /*
1095 ** Two transitions per year, from EPOCH_YEAR forward.
1096 */
1097 init_ttinfo(&sp->ttis[0], -dstoffset, true, stdlen + 1);
1098 init_ttinfo(&sp->ttis[1], -stdoffset, false, 0);
1099 sp->defaulttype = 0;
1100 timecnt = 0;
1101 janfirst = 0;
1102 yearlim = EPOCH_YEAR + YEARSPERREPEAT;
1103 for (year = EPOCH_YEAR; year < yearlim; year++) {
1104 int_fast32_t
1105 starttime = transtime(year, &start, stdoffset),
1106 endtime = transtime(year, &end, dstoffset);
1107 int_fast32_t
1108 yearsecs = (year_lengths[isleap(year)]
1109 * SECSPERDAY);
1110 bool reversed = endtime < starttime;
1111 if (reversed) {
1112 int_fast32_t swap = starttime;
1113 starttime = endtime;
1114 endtime = swap;
1115 }
1116 if (reversed
1117 || (starttime < endtime
1118 && (endtime - starttime
1119 < (yearsecs
1120 + (stdoffset - dstoffset))))) {
1121 if (TZ_MAX_TIMES - 2 < timecnt)
1122 break;
1123 yearlim = year + YEARSPERREPEAT + 1;
1124 sp->ats[timecnt] = janfirst;
1125 if (increment_overflow_time
1126 (&sp->ats[timecnt], starttime))
1127 break;
1128 sp->types[timecnt++] = reversed;
1129 sp->ats[timecnt] = janfirst;
1130 if (increment_overflow_time
1131 (&sp->ats[timecnt], endtime))
1132 break;
1133 sp->types[timecnt++] = !reversed;
1134 }
1135 if (increment_overflow_time(&janfirst, yearsecs))
1136 break;
1137 }
1138 sp->timecnt = timecnt;
1139 if (!timecnt)
1140 sp->typecnt = 1; /* Perpetual DST. */
1141 } else {
1142 register int_fast32_t theirstdoffset;
1143 register int_fast32_t theirdstoffset;
1144 register int_fast32_t theiroffset;
1145 register bool isdst;
1146 register int i;
1147 register int j;
1148
1149 if (*name != '\0')
1150 return false;
1151 /*
1152 ** Initial values of theirstdoffset and theirdstoffset.
1153 */
1154 theirstdoffset = 0;
1155 for (i = 0; i < sp->timecnt; ++i) {
1156 j = sp->types[i];
1157 if (!sp->ttis[j].tt_isdst) {
1158 theirstdoffset =
1159 -sp->ttis[j].tt_gmtoff;
1160 break;
1161 }
1162 }
1163 theirdstoffset = 0;
1164 for (i = 0; i < sp->timecnt; ++i) {
1165 j = sp->types[i];
1166 if (sp->ttis[j].tt_isdst) {
1167 theirdstoffset =
1168 -sp->ttis[j].tt_gmtoff;
1169 break;
1170 }
1171 }
1172 /*
1173 ** Initially we're assumed to be in standard time.
1174 */
1175 isdst = false;
1176 theiroffset = theirstdoffset;
1177 /*
1178 ** Now juggle transition times and types
1179 ** tracking offsets as you do.
1180 */
1181 for (i = 0; i < sp->timecnt; ++i) {
1182 j = sp->types[i];
1183 sp->types[i] = sp->ttis[j].tt_isdst;
1184 if (sp->ttis[j].tt_ttisgmt) {
1185 /* No adjustment to transition time */
1186 } else {
1187 /*
1188 ** If summer time is in effect, and the
1189 ** transition time was not specified as
1190 ** standard time, add the summer time
1191 ** offset to the transition time;
1192 ** otherwise, add the standard time
1193 ** offset to the transition time.
1194 */
1195 /*
1196 ** Transitions from DST to DDST
1197 ** will effectively disappear since
1198 ** POSIX provides for only one DST
1199 ** offset.
1200 */
1201 if (isdst && !sp->ttis[j].tt_ttisstd) {
1202 sp->ats[i] += dstoffset -
1203 theirdstoffset;
1204 } else {
1205 sp->ats[i] += stdoffset -
1206 theirstdoffset;
1207 }
1208 }
1209 theiroffset = -sp->ttis[j].tt_gmtoff;
1210 if (sp->ttis[j].tt_isdst)
1211 theirdstoffset = theiroffset;
1212 else theirstdoffset = theiroffset;
1213 }
1214 /*
1215 ** Finally, fill in ttis.
1216 */
1217 init_ttinfo(&sp->ttis[0], -stdoffset, false, 0);
1218 init_ttinfo(&sp->ttis[1], -dstoffset, true, stdlen + 1);
1219 sp->typecnt = 2;
1220 sp->defaulttype = 0;
1221 }
1222 } else {
1223 dstlen = 0;
1224 sp->typecnt = 1; /* only standard time */
1225 sp->timecnt = 0;
1226 init_ttinfo(&sp->ttis[0], -stdoffset, false, 0);
1227 sp->defaulttype = 0;
1228 }
1229 sp->charcnt = charcnt;
1230 cp = sp->chars;
1231 memcpy(cp, stdname, stdlen);
1232 cp += stdlen;
1233 *cp++ = '\0';
1234 if (dstlen != 0) {
1235 memcpy(cp, dstname, dstlen);
1236 *(cp + dstlen) = '\0';
1237 }
1238 return true;
1239 }
1240
1241 static void
gmtload(struct state * const sp)1242 gmtload(struct state *const sp)
1243 {
1244 if (tzload(gmt, sp, true) != 0)
1245 tzparse(gmt, sp, true);
1246 }
1247
1248 /* Initialize *SP to a value appropriate for the TZ setting NAME.
1249 Return 0 on success, an errno value on failure. */
1250 static int
zoneinit(struct state * sp,char const * name)1251 zoneinit(struct state *sp, char const *name)
1252 {
1253 if (name && ! name[0]) {
1254 /*
1255 ** User wants it fast rather than right.
1256 */
1257 sp->leapcnt = 0; /* so, we're off a little */
1258 sp->timecnt = 0;
1259 sp->typecnt = 0;
1260 sp->charcnt = 0;
1261 sp->goback = sp->goahead = false;
1262 init_ttinfo(&sp->ttis[0], 0, false, 0);
1263 strcpy(sp->chars, gmt);
1264 sp->defaulttype = 0;
1265 return 0;
1266 } else {
1267 int err = tzload(name, sp, true);
1268 if (err != 0 && name && name[0] != ':' && tzparse(name, sp, false))
1269 err = 0;
1270 if (err == 0)
1271 scrub_abbrs(sp);
1272 return err;
1273 }
1274 }
1275
1276 static void
tzsetlcl(char const * name)1277 tzsetlcl(char const *name)
1278 {
1279 struct state *sp = lclptr;
1280 int lcl = name ? strlen(name) < sizeof lcl_TZname : -1;
1281 if (lcl < 0
1282 ? lcl_is_set < 0
1283 : 0 < lcl_is_set && strcmp(lcl_TZname, name) == 0)
1284 return;
1285 #ifdef ALL_STATE
1286 if (! sp)
1287 lclptr = sp = malloc(sizeof *lclptr);
1288 #endif /* defined ALL_STATE */
1289 if (sp) {
1290 if (zoneinit(sp, name) != 0)
1291 zoneinit(sp, "");
1292 if (0 < lcl)
1293 strcpy(lcl_TZname, name);
1294 }
1295 settzname();
1296 lcl_is_set = lcl;
1297 }
1298
1299 #ifdef STD_INSPIRED
1300 void
tzsetwall(void)1301 tzsetwall(void)
1302 {
1303 if (lock() != 0)
1304 return;
1305 tzsetlcl(NULL);
1306 unlock();
1307 }
1308 #endif
1309
1310 #if defined(__ANDROID__)
1311 #define _REALLY_INCLUDE_SYS__SYSTEM_PROPERTIES_H_
1312 #include <sys/_system_properties.h> // For __system_property_serial.
1313 #endif
1314
1315 static void
tzset_unlocked(void)1316 tzset_unlocked(void)
1317 {
1318 #if defined(__ANDROID__)
1319 // The TZ environment variable is meant to override the system-wide setting.
1320 const char * name = getenv("TZ");
1321
1322 // If that's not set, look at the "persist.sys.timezone" system property.
1323 if (name == NULL) {
1324 static const prop_info *pi;
1325
1326 if (!pi) {
1327 pi = __system_property_find("persist.sys.timezone");
1328 }
1329 if (pi) {
1330 static char buf[PROP_VALUE_MAX];
1331 static uint32_t s = -1;
1332 static bool ok = false;
1333 uint32_t serial = __system_property_serial(pi);
1334 if (serial != s) {
1335 ok = __system_property_read(pi, 0, buf) > 0;
1336 s = serial;
1337 }
1338 if (ok) {
1339 name = buf;
1340 }
1341 }
1342 }
1343
1344 // If that's not available (because you're running AOSP on a WiFi-only
1345 // device, say), fall back to GMT.
1346 if (name == NULL) name = gmt;
1347
1348 tzsetlcl(name);
1349 #else
1350 tzsetlcl(getenv("TZ"));
1351 #endif
1352 }
1353
1354 void
tzset(void)1355 tzset(void)
1356 {
1357 if (lock() != 0)
1358 return;
1359 tzset_unlocked();
1360 unlock();
1361 }
1362
1363 static void
gmtcheck(void)1364 gmtcheck(void)
1365 {
1366 static bool gmt_is_set;
1367 if (lock() != 0)
1368 return;
1369 if (! gmt_is_set) {
1370 #ifdef ALL_STATE
1371 gmtptr = malloc(sizeof *gmtptr);
1372 #endif
1373 if (gmtptr)
1374 gmtload(gmtptr);
1375 gmt_is_set = true;
1376 }
1377 unlock();
1378 }
1379
1380 #if NETBSD_INSPIRED
1381
1382 timezone_t
tzalloc(char const * name)1383 tzalloc(char const *name)
1384 {
1385 timezone_t sp = malloc(sizeof *sp);
1386 if (sp) {
1387 int err = zoneinit(sp, name);
1388 if (err != 0) {
1389 free(sp);
1390 errno = err;
1391 return NULL;
1392 }
1393 }
1394 return sp;
1395 }
1396
1397 void
tzfree(timezone_t sp)1398 tzfree(timezone_t sp)
1399 {
1400 free(sp);
1401 }
1402
1403 /*
1404 ** NetBSD 6.1.4 has ctime_rz, but omit it because POSIX says ctime and
1405 ** ctime_r are obsolescent and have potential security problems that
1406 ** ctime_rz would share. Callers can instead use localtime_rz + strftime.
1407 **
1408 ** NetBSD 6.1.4 has tzgetname, but omit it because it doesn't work
1409 ** in zones with three or more time zone abbreviations.
1410 ** Callers can instead use localtime_rz + strftime.
1411 */
1412
1413 #endif
1414
1415 /*
1416 ** The easy way to behave "as if no library function calls" localtime
1417 ** is to not call it, so we drop its guts into "localsub", which can be
1418 ** freely called. (And no, the PANS doesn't require the above behavior,
1419 ** but it *is* desirable.)
1420 **
1421 ** If successful and SETNAME is nonzero,
1422 ** set the applicable parts of tzname, timezone and altzone;
1423 ** however, it's OK to omit this step if the time zone is POSIX-compatible,
1424 ** since in that case tzset should have already done this step correctly.
1425 ** SETNAME's type is intfast32_t for compatibility with gmtsub,
1426 ** but it is actually a boolean and its value should be 0 or 1.
1427 */
1428
1429 /*ARGSUSED*/
1430 static struct tm *
localsub(struct state const * sp,time_t const * timep,int_fast32_t setname,struct tm * const tmp)1431 localsub(struct state const *sp, time_t const *timep, int_fast32_t setname,
1432 struct tm *const tmp)
1433 {
1434 register const struct ttinfo * ttisp;
1435 register int i;
1436 register struct tm * result;
1437 const time_t t = *timep;
1438
1439 if (sp == NULL) {
1440 /* Don't bother to set tzname etc.; tzset has already done it. */
1441 return gmtsub(gmtptr, timep, 0, tmp);
1442 }
1443 if ((sp->goback && t < sp->ats[0]) ||
1444 (sp->goahead && t > sp->ats[sp->timecnt - 1])) {
1445 time_t newt = t;
1446 register time_t seconds;
1447 register time_t years;
1448
1449 if (t < sp->ats[0])
1450 seconds = sp->ats[0] - t;
1451 else seconds = t - sp->ats[sp->timecnt - 1];
1452 --seconds;
1453 years = (seconds / SECSPERREPEAT + 1) * YEARSPERREPEAT;
1454 seconds = years * AVGSECSPERYEAR;
1455 if (t < sp->ats[0])
1456 newt += seconds;
1457 else newt -= seconds;
1458 if (newt < sp->ats[0] ||
1459 newt > sp->ats[sp->timecnt - 1])
1460 return NULL; /* "cannot happen" */
1461 result = localsub(sp, &newt, setname, tmp);
1462 if (result) {
1463 register int_fast64_t newy;
1464
1465 newy = result->tm_year;
1466 if (t < sp->ats[0])
1467 newy -= years;
1468 else newy += years;
1469 if (! (INT_MIN <= newy && newy <= INT_MAX))
1470 return NULL;
1471 result->tm_year = newy;
1472 }
1473 return result;
1474 }
1475 if (sp->timecnt == 0 || t < sp->ats[0]) {
1476 i = sp->defaulttype;
1477 } else {
1478 register int lo = 1;
1479 register int hi = sp->timecnt;
1480
1481 while (lo < hi) {
1482 register int mid = (lo + hi) >> 1;
1483
1484 if (t < sp->ats[mid])
1485 hi = mid;
1486 else lo = mid + 1;
1487 }
1488 i = (int) sp->types[lo - 1];
1489 }
1490 ttisp = &sp->ttis[i];
1491 /*
1492 ** To get (wrong) behavior that's compatible with System V Release 2.0
1493 ** you'd replace the statement below with
1494 ** t += ttisp->tt_gmtoff;
1495 ** timesub(&t, 0L, sp, tmp);
1496 */
1497 result = timesub(&t, ttisp->tt_gmtoff, sp, tmp);
1498 if (result) {
1499 result->tm_isdst = ttisp->tt_isdst;
1500 #ifdef TM_ZONE
1501 result->TM_ZONE = (char *) &sp->chars[ttisp->tt_abbrind];
1502 #endif /* defined TM_ZONE */
1503 if (setname)
1504 update_tzname_etc(sp, ttisp);
1505 }
1506 return result;
1507 }
1508
1509 #if NETBSD_INSPIRED
1510
1511 struct tm *
localtime_rz(struct state * sp,time_t const * timep,struct tm * tmp)1512 localtime_rz(struct state *sp, time_t const *timep, struct tm *tmp)
1513 {
1514 return localsub(sp, timep, 0, tmp);
1515 }
1516
1517 #endif
1518
1519 static struct tm *
localtime_tzset(time_t const * timep,struct tm * tmp,bool setname)1520 localtime_tzset(time_t const *timep, struct tm *tmp, bool setname)
1521 {
1522 int err = lock();
1523 if (err) {
1524 errno = err;
1525 return NULL;
1526 }
1527 if (setname || !lcl_is_set)
1528 tzset_unlocked();
1529 tmp = localsub(lclptr, timep, setname, tmp);
1530 unlock();
1531 return tmp;
1532 }
1533
1534 struct tm *
localtime(const time_t * timep)1535 localtime(const time_t *timep)
1536 {
1537 return localtime_tzset(timep, &tm, true);
1538 }
1539
1540 struct tm *
localtime_r(const time_t * timep,struct tm * tmp)1541 localtime_r(const time_t *timep, struct tm *tmp)
1542 {
1543 return localtime_tzset(timep, tmp, false);
1544 }
1545
1546 /*
1547 ** gmtsub is to gmtime as localsub is to localtime.
1548 */
1549
1550 static struct tm *
gmtsub(struct state const * sp,time_t const * timep,int_fast32_t offset,struct tm * tmp)1551 gmtsub(struct state const *sp, time_t const *timep, int_fast32_t offset,
1552 struct tm *tmp)
1553 {
1554 register struct tm * result;
1555
1556 result = timesub(timep, offset, gmtptr, tmp);
1557 #ifdef TM_ZONE
1558 /*
1559 ** Could get fancy here and deliver something such as
1560 ** "UT+xxxx" or "UT-xxxx" if offset is non-zero,
1561 ** but this is no time for a treasure hunt.
1562 */
1563 tmp->TM_ZONE = ((char *)
1564 (offset ? wildabbr : gmtptr ? gmtptr->chars : gmt));
1565 #endif /* defined TM_ZONE */
1566 return result;
1567 }
1568
1569 /*
1570 * Re-entrant version of gmtime.
1571 */
1572
1573 struct tm *
gmtime_r(const time_t * timep,struct tm * tmp)1574 gmtime_r(const time_t *timep, struct tm *tmp)
1575 {
1576 gmtcheck();
1577 return gmtsub(gmtptr, timep, 0, tmp);
1578 }
1579
1580 struct tm *
gmtime(const time_t * timep)1581 gmtime(const time_t *timep)
1582 {
1583 return gmtime_r(timep, &tm);
1584 }
1585
1586 #ifdef STD_INSPIRED
1587
1588 struct tm *
offtime(const time_t * timep,long offset)1589 offtime(const time_t *timep, long offset)
1590 {
1591 gmtcheck();
1592 return gmtsub(gmtptr, timep, offset, &tm);
1593 }
1594
1595 #endif /* defined STD_INSPIRED */
1596
1597 /*
1598 ** Return the number of leap years through the end of the given year
1599 ** where, to make the math easy, the answer for year zero is defined as zero.
1600 */
1601
1602 static int ATTRIBUTE_PURE
leaps_thru_end_of(register const int y)1603 leaps_thru_end_of(register const int y)
1604 {
1605 return (y >= 0) ? (y / 4 - y / 100 + y / 400) :
1606 -(leaps_thru_end_of(-(y + 1)) + 1);
1607 }
1608
1609 static struct tm *
timesub(const time_t * timep,int_fast32_t offset,const struct state * sp,struct tm * tmp)1610 timesub(const time_t *timep, int_fast32_t offset,
1611 const struct state *sp, struct tm *tmp)
1612 {
1613 register const struct lsinfo * lp;
1614 register time_t tdays;
1615 register int idays; /* unsigned would be so 2003 */
1616 register int_fast64_t rem;
1617 int y;
1618 register const int * ip;
1619 register int_fast64_t corr;
1620 register bool hit;
1621 register int i;
1622
1623 corr = 0;
1624 hit = false;
1625 i = (sp == NULL) ? 0 : sp->leapcnt;
1626 while (--i >= 0) {
1627 lp = &sp->lsis[i];
1628 if (*timep >= lp->ls_trans) {
1629 if (*timep == lp->ls_trans) {
1630 hit = ((i == 0 && lp->ls_corr > 0) ||
1631 lp->ls_corr > sp->lsis[i - 1].ls_corr);
1632 if (hit)
1633 while (i > 0 &&
1634 sp->lsis[i].ls_trans ==
1635 sp->lsis[i - 1].ls_trans + 1 &&
1636 sp->lsis[i].ls_corr ==
1637 sp->lsis[i - 1].ls_corr + 1) {
1638 ++hit;
1639 --i;
1640 }
1641 }
1642 corr = lp->ls_corr;
1643 break;
1644 }
1645 }
1646 y = EPOCH_YEAR;
1647 tdays = *timep / SECSPERDAY;
1648 rem = *timep % SECSPERDAY;
1649 while (tdays < 0 || tdays >= year_lengths[isleap(y)]) {
1650 int newy;
1651 register time_t tdelta;
1652 register int idelta;
1653 register int leapdays;
1654
1655 tdelta = tdays / DAYSPERLYEAR;
1656 if (! ((! TYPE_SIGNED(time_t) || INT_MIN <= tdelta)
1657 && tdelta <= INT_MAX))
1658 goto out_of_range;
1659 idelta = tdelta;
1660 if (idelta == 0)
1661 idelta = (tdays < 0) ? -1 : 1;
1662 newy = y;
1663 if (increment_overflow(&newy, idelta))
1664 goto out_of_range;
1665 leapdays = leaps_thru_end_of(newy - 1) -
1666 leaps_thru_end_of(y - 1);
1667 tdays -= ((time_t) newy - y) * DAYSPERNYEAR;
1668 tdays -= leapdays;
1669 y = newy;
1670 }
1671 /*
1672 ** Given the range, we can now fearlessly cast...
1673 */
1674 idays = tdays;
1675 rem += offset - corr;
1676 while (rem < 0) {
1677 rem += SECSPERDAY;
1678 --idays;
1679 }
1680 while (rem >= SECSPERDAY) {
1681 rem -= SECSPERDAY;
1682 ++idays;
1683 }
1684 while (idays < 0) {
1685 if (increment_overflow(&y, -1))
1686 goto out_of_range;
1687 idays += year_lengths[isleap(y)];
1688 }
1689 while (idays >= year_lengths[isleap(y)]) {
1690 idays -= year_lengths[isleap(y)];
1691 if (increment_overflow(&y, 1))
1692 goto out_of_range;
1693 }
1694 tmp->tm_year = y;
1695 if (increment_overflow(&tmp->tm_year, -TM_YEAR_BASE))
1696 goto out_of_range;
1697 tmp->tm_yday = idays;
1698 /*
1699 ** The "extra" mods below avoid overflow problems.
1700 */
1701 tmp->tm_wday = EPOCH_WDAY +
1702 ((y - EPOCH_YEAR) % DAYSPERWEEK) *
1703 (DAYSPERNYEAR % DAYSPERWEEK) +
1704 leaps_thru_end_of(y - 1) -
1705 leaps_thru_end_of(EPOCH_YEAR - 1) +
1706 idays;
1707 tmp->tm_wday %= DAYSPERWEEK;
1708 if (tmp->tm_wday < 0)
1709 tmp->tm_wday += DAYSPERWEEK;
1710 tmp->tm_hour = (int) (rem / SECSPERHOUR);
1711 rem %= SECSPERHOUR;
1712 tmp->tm_min = (int) (rem / SECSPERMIN);
1713 /*
1714 ** A positive leap second requires a special
1715 ** representation. This uses "... ??:59:60" et seq.
1716 */
1717 tmp->tm_sec = (int) (rem % SECSPERMIN) + hit;
1718 ip = mon_lengths[isleap(y)];
1719 for (tmp->tm_mon = 0; idays >= ip[tmp->tm_mon]; ++(tmp->tm_mon))
1720 idays -= ip[tmp->tm_mon];
1721 tmp->tm_mday = (int) (idays + 1);
1722 tmp->tm_isdst = 0;
1723 #ifdef TM_GMTOFF
1724 tmp->TM_GMTOFF = offset;
1725 #endif /* defined TM_GMTOFF */
1726 return tmp;
1727
1728 out_of_range:
1729 errno = EOVERFLOW;
1730 return NULL;
1731 }
1732
1733 char *
ctime(const time_t * timep)1734 ctime(const time_t *timep)
1735 {
1736 /*
1737 ** Section 4.12.3.2 of X3.159-1989 requires that
1738 ** The ctime function converts the calendar time pointed to by timer
1739 ** to local time in the form of a string. It is equivalent to
1740 ** asctime(localtime(timer))
1741 */
1742 struct tm *tmp = localtime(timep);
1743 return tmp ? asctime(tmp) : NULL;
1744 }
1745
1746 char *
ctime_r(const time_t * timep,char * buf)1747 ctime_r(const time_t *timep, char *buf)
1748 {
1749 struct tm mytm;
1750 struct tm *tmp = localtime_r(timep, &mytm);
1751 return tmp ? asctime_r(tmp, buf) : NULL;
1752 }
1753
1754 /*
1755 ** Adapted from code provided by Robert Elz, who writes:
1756 ** The "best" way to do mktime I think is based on an idea of Bob
1757 ** Kridle's (so its said...) from a long time ago.
1758 ** It does a binary search of the time_t space. Since time_t's are
1759 ** just 32 bits, its a max of 32 iterations (even at 64 bits it
1760 ** would still be very reasonable).
1761 */
1762
1763 #ifndef WRONG
1764 #define WRONG (-1)
1765 #endif /* !defined WRONG */
1766
1767 /*
1768 ** Normalize logic courtesy Paul Eggert.
1769 */
1770
1771 static bool
increment_overflow(int * ip,int j)1772 increment_overflow(int *ip, int j)
1773 {
1774 register int const i = *ip;
1775
1776 /*
1777 ** If i >= 0 there can only be overflow if i + j > INT_MAX
1778 ** or if j > INT_MAX - i; given i >= 0, INT_MAX - i cannot overflow.
1779 ** If i < 0 there can only be overflow if i + j < INT_MIN
1780 ** or if j < INT_MIN - i; given i < 0, INT_MIN - i cannot overflow.
1781 */
1782 if ((i >= 0) ? (j > INT_MAX - i) : (j < INT_MIN - i))
1783 return true;
1784 *ip += j;
1785 return false;
1786 }
1787
1788 static bool
increment_overflow32(int_fast32_t * const lp,int const m)1789 increment_overflow32(int_fast32_t *const lp, int const m)
1790 {
1791 register int_fast32_t const l = *lp;
1792
1793 if ((l >= 0) ? (m > INT_FAST32_MAX - l) : (m < INT_FAST32_MIN - l))
1794 return true;
1795 *lp += m;
1796 return false;
1797 }
1798
1799 static bool
increment_overflow_time(time_t * tp,int_fast32_t j)1800 increment_overflow_time(time_t *tp, int_fast32_t j)
1801 {
1802 /*
1803 ** This is like
1804 ** 'if (! (time_t_min <= *tp + j && *tp + j <= time_t_max)) ...',
1805 ** except that it does the right thing even if *tp + j would overflow.
1806 */
1807 if (! (j < 0
1808 ? (TYPE_SIGNED(time_t) ? time_t_min - j <= *tp : -1 - j < *tp)
1809 : *tp <= time_t_max - j))
1810 return true;
1811 *tp += j;
1812 return false;
1813 }
1814
1815 static bool
normalize_overflow(int * const tensptr,int * const unitsptr,const int base)1816 normalize_overflow(int *const tensptr, int *const unitsptr, const int base)
1817 {
1818 register int tensdelta;
1819
1820 tensdelta = (*unitsptr >= 0) ?
1821 (*unitsptr / base) :
1822 (-1 - (-1 - *unitsptr) / base);
1823 *unitsptr -= tensdelta * base;
1824 return increment_overflow(tensptr, tensdelta);
1825 }
1826
1827 static bool
normalize_overflow32(int_fast32_t * tensptr,int * unitsptr,int base)1828 normalize_overflow32(int_fast32_t *tensptr, int *unitsptr, int base)
1829 {
1830 register int tensdelta;
1831
1832 tensdelta = (*unitsptr >= 0) ?
1833 (*unitsptr / base) :
1834 (-1 - (-1 - *unitsptr) / base);
1835 *unitsptr -= tensdelta * base;
1836 return increment_overflow32(tensptr, tensdelta);
1837 }
1838
1839 static int
tmcomp(register const struct tm * const atmp,register const struct tm * const btmp)1840 tmcomp(register const struct tm *const atmp,
1841 register const struct tm *const btmp)
1842 {
1843 register int result;
1844
1845 if (atmp->tm_year != btmp->tm_year)
1846 return atmp->tm_year < btmp->tm_year ? -1 : 1;
1847 if ((result = (atmp->tm_mon - btmp->tm_mon)) == 0 &&
1848 (result = (atmp->tm_mday - btmp->tm_mday)) == 0 &&
1849 (result = (atmp->tm_hour - btmp->tm_hour)) == 0 &&
1850 (result = (atmp->tm_min - btmp->tm_min)) == 0)
1851 result = atmp->tm_sec - btmp->tm_sec;
1852 return result;
1853 }
1854
1855 static time_t
time2sub(struct tm * const tmp,struct tm * (* funcp)(struct state const *,time_t const *,int_fast32_t,struct tm *),struct state const * sp,const int_fast32_t offset,bool * okayp,bool do_norm_secs)1856 time2sub(struct tm *const tmp,
1857 struct tm *(*funcp)(struct state const *, time_t const *,
1858 int_fast32_t, struct tm *),
1859 struct state const *sp,
1860 const int_fast32_t offset,
1861 bool *okayp,
1862 bool do_norm_secs)
1863 {
1864 register int dir;
1865 register int i, j;
1866 register int saved_seconds;
1867 register int_fast32_t li;
1868 register time_t lo;
1869 register time_t hi;
1870 int_fast32_t y;
1871 time_t newt;
1872 time_t t;
1873 struct tm yourtm, mytm;
1874
1875 *okayp = false;
1876 yourtm = *tmp;
1877 if (do_norm_secs) {
1878 if (normalize_overflow(&yourtm.tm_min, &yourtm.tm_sec,
1879 SECSPERMIN))
1880 return WRONG;
1881 }
1882 if (normalize_overflow(&yourtm.tm_hour, &yourtm.tm_min, MINSPERHOUR))
1883 return WRONG;
1884 if (normalize_overflow(&yourtm.tm_mday, &yourtm.tm_hour, HOURSPERDAY))
1885 return WRONG;
1886 y = yourtm.tm_year;
1887 if (normalize_overflow32(&y, &yourtm.tm_mon, MONSPERYEAR))
1888 return WRONG;
1889 /*
1890 ** Turn y into an actual year number for now.
1891 ** It is converted back to an offset from TM_YEAR_BASE later.
1892 */
1893 if (increment_overflow32(&y, TM_YEAR_BASE))
1894 return WRONG;
1895 while (yourtm.tm_mday <= 0) {
1896 if (increment_overflow32(&y, -1))
1897 return WRONG;
1898 li = y + (1 < yourtm.tm_mon);
1899 yourtm.tm_mday += year_lengths[isleap(li)];
1900 }
1901 while (yourtm.tm_mday > DAYSPERLYEAR) {
1902 li = y + (1 < yourtm.tm_mon);
1903 yourtm.tm_mday -= year_lengths[isleap(li)];
1904 if (increment_overflow32(&y, 1))
1905 return WRONG;
1906 }
1907 for ( ; ; ) {
1908 i = mon_lengths[isleap(y)][yourtm.tm_mon];
1909 if (yourtm.tm_mday <= i)
1910 break;
1911 yourtm.tm_mday -= i;
1912 if (++yourtm.tm_mon >= MONSPERYEAR) {
1913 yourtm.tm_mon = 0;
1914 if (increment_overflow32(&y, 1))
1915 return WRONG;
1916 }
1917 }
1918 if (increment_overflow32(&y, -TM_YEAR_BASE))
1919 return WRONG;
1920 if (! (INT_MIN <= y && y <= INT_MAX))
1921 return WRONG;
1922 yourtm.tm_year = y;
1923 if (yourtm.tm_sec >= 0 && yourtm.tm_sec < SECSPERMIN)
1924 saved_seconds = 0;
1925 else if (y + TM_YEAR_BASE < EPOCH_YEAR) {
1926 /*
1927 ** We can't set tm_sec to 0, because that might push the
1928 ** time below the minimum representable time.
1929 ** Set tm_sec to 59 instead.
1930 ** This assumes that the minimum representable time is
1931 ** not in the same minute that a leap second was deleted from,
1932 ** which is a safer assumption than using 58 would be.
1933 */
1934 if (increment_overflow(&yourtm.tm_sec, 1 - SECSPERMIN))
1935 return WRONG;
1936 saved_seconds = yourtm.tm_sec;
1937 yourtm.tm_sec = SECSPERMIN - 1;
1938 } else {
1939 saved_seconds = yourtm.tm_sec;
1940 yourtm.tm_sec = 0;
1941 }
1942 /*
1943 ** Do a binary search (this works whatever time_t's type is).
1944 */
1945 lo = time_t_min;
1946 hi = time_t_max;
1947 for ( ; ; ) {
1948 t = lo / 2 + hi / 2;
1949 if (t < lo)
1950 t = lo;
1951 else if (t > hi)
1952 t = hi;
1953 if (! funcp(sp, &t, offset, &mytm)) {
1954 /*
1955 ** Assume that t is too extreme to be represented in
1956 ** a struct tm; arrange things so that it is less
1957 ** extreme on the next pass.
1958 */
1959 dir = (t > 0) ? 1 : -1;
1960 } else dir = tmcomp(&mytm, &yourtm);
1961 if (dir != 0) {
1962 if (t == lo) {
1963 if (t == time_t_max)
1964 return WRONG;
1965 ++t;
1966 ++lo;
1967 } else if (t == hi) {
1968 if (t == time_t_min)
1969 return WRONG;
1970 --t;
1971 --hi;
1972 }
1973 if (lo > hi)
1974 return WRONG;
1975 if (dir > 0)
1976 hi = t;
1977 else lo = t;
1978 continue;
1979 }
1980 #if defined TM_GMTOFF && ! UNINIT_TRAP
1981 if (mytm.TM_GMTOFF != yourtm.TM_GMTOFF
1982 && (yourtm.TM_GMTOFF < 0
1983 ? (-SECSPERDAY <= yourtm.TM_GMTOFF
1984 && (mytm.TM_GMTOFF <=
1985 (SMALLEST (INT_FAST32_MAX, LONG_MAX)
1986 + yourtm.TM_GMTOFF)))
1987 : (yourtm.TM_GMTOFF <= SECSPERDAY
1988 && ((BIGGEST (INT_FAST32_MIN, LONG_MIN)
1989 + yourtm.TM_GMTOFF)
1990 <= mytm.TM_GMTOFF)))) {
1991 /* MYTM matches YOURTM except with the wrong UTC offset.
1992 YOURTM.TM_GMTOFF is plausible, so try it instead.
1993 It's OK if YOURTM.TM_GMTOFF contains uninitialized data,
1994 since the guess gets checked. */
1995 time_t altt = t;
1996 int_fast32_t diff = mytm.TM_GMTOFF - yourtm.TM_GMTOFF;
1997 if (!increment_overflow_time(&altt, diff)) {
1998 struct tm alttm;
1999 if (funcp(sp, &altt, offset, &alttm)
2000 && alttm.tm_isdst == mytm.tm_isdst
2001 && alttm.TM_GMTOFF == yourtm.TM_GMTOFF
2002 && tmcomp(&alttm, &yourtm) == 0) {
2003 t = altt;
2004 mytm = alttm;
2005 }
2006 }
2007 }
2008 #endif
2009 if (yourtm.tm_isdst < 0 || mytm.tm_isdst == yourtm.tm_isdst)
2010 break;
2011 /*
2012 ** Right time, wrong type.
2013 ** Hunt for right time, right type.
2014 ** It's okay to guess wrong since the guess
2015 ** gets checked.
2016 */
2017 if (sp == NULL)
2018 return WRONG;
2019 for (i = sp->typecnt - 1; i >= 0; --i) {
2020 if (sp->ttis[i].tt_isdst != yourtm.tm_isdst)
2021 continue;
2022 for (j = sp->typecnt - 1; j >= 0; --j) {
2023 if (sp->ttis[j].tt_isdst == yourtm.tm_isdst)
2024 continue;
2025 newt = t + sp->ttis[j].tt_gmtoff -
2026 sp->ttis[i].tt_gmtoff;
2027 if (! funcp(sp, &newt, offset, &mytm))
2028 continue;
2029 if (tmcomp(&mytm, &yourtm) != 0)
2030 continue;
2031 if (mytm.tm_isdst != yourtm.tm_isdst)
2032 continue;
2033 /*
2034 ** We have a match.
2035 */
2036 t = newt;
2037 goto label;
2038 }
2039 }
2040 return WRONG;
2041 }
2042 label:
2043 newt = t + saved_seconds;
2044 if ((newt < t) != (saved_seconds < 0))
2045 return WRONG;
2046 t = newt;
2047 if (funcp(sp, &t, offset, tmp))
2048 *okayp = true;
2049 return t;
2050 }
2051
2052 static time_t
time2(struct tm * const tmp,struct tm * (* funcp)(struct state const *,time_t const *,int_fast32_t,struct tm *),struct state const * sp,const int_fast32_t offset,bool * okayp)2053 time2(struct tm * const tmp,
2054 struct tm *(*funcp)(struct state const *, time_t const *,
2055 int_fast32_t, struct tm *),
2056 struct state const *sp,
2057 const int_fast32_t offset,
2058 bool *okayp)
2059 {
2060 time_t t;
2061
2062 /*
2063 ** First try without normalization of seconds
2064 ** (in case tm_sec contains a value associated with a leap second).
2065 ** If that fails, try with normalization of seconds.
2066 */
2067 t = time2sub(tmp, funcp, sp, offset, okayp, false);
2068 return *okayp ? t : time2sub(tmp, funcp, sp, offset, okayp, true);
2069 }
2070
2071 static time_t
time1(struct tm * const tmp,struct tm * (* funcp)(struct state const *,time_t const *,int_fast32_t,struct tm *),struct state const * sp,const int_fast32_t offset)2072 time1(struct tm *const tmp,
2073 struct tm *(*funcp) (struct state const *, time_t const *,
2074 int_fast32_t, struct tm *),
2075 struct state const *sp,
2076 const int_fast32_t offset)
2077 {
2078 register time_t t;
2079 register int samei, otheri;
2080 register int sameind, otherind;
2081 register int i;
2082 register int nseen;
2083 char seen[TZ_MAX_TYPES];
2084 unsigned char types[TZ_MAX_TYPES];
2085 bool okay;
2086
2087 if (tmp == NULL) {
2088 errno = EINVAL;
2089 return WRONG;
2090 }
2091 if (tmp->tm_isdst > 1)
2092 tmp->tm_isdst = 1;
2093 t = time2(tmp, funcp, sp, offset, &okay);
2094 if (okay)
2095 return t;
2096 if (tmp->tm_isdst < 0)
2097 #ifdef PCTS
2098 /*
2099 ** POSIX Conformance Test Suite code courtesy Grant Sullivan.
2100 */
2101 tmp->tm_isdst = 0; /* reset to std and try again */
2102 #else
2103 return t;
2104 #endif /* !defined PCTS */
2105 /*
2106 ** We're supposed to assume that somebody took a time of one type
2107 ** and did some math on it that yielded a "struct tm" that's bad.
2108 ** We try to divine the type they started from and adjust to the
2109 ** type they need.
2110 */
2111 if (sp == NULL)
2112 return WRONG;
2113 for (i = 0; i < sp->typecnt; ++i)
2114 seen[i] = false;
2115 nseen = 0;
2116 for (i = sp->timecnt - 1; i >= 0; --i)
2117 if (!seen[sp->types[i]]) {
2118 seen[sp->types[i]] = true;
2119 types[nseen++] = sp->types[i];
2120 }
2121 for (sameind = 0; sameind < nseen; ++sameind) {
2122 samei = types[sameind];
2123 if (sp->ttis[samei].tt_isdst != tmp->tm_isdst)
2124 continue;
2125 for (otherind = 0; otherind < nseen; ++otherind) {
2126 otheri = types[otherind];
2127 if (sp->ttis[otheri].tt_isdst == tmp->tm_isdst)
2128 continue;
2129 tmp->tm_sec += sp->ttis[otheri].tt_gmtoff -
2130 sp->ttis[samei].tt_gmtoff;
2131 tmp->tm_isdst = !tmp->tm_isdst;
2132 t = time2(tmp, funcp, sp, offset, &okay);
2133 if (okay)
2134 return t;
2135 tmp->tm_sec -= sp->ttis[otheri].tt_gmtoff -
2136 sp->ttis[samei].tt_gmtoff;
2137 tmp->tm_isdst = !tmp->tm_isdst;
2138 }
2139 }
2140 return WRONG;
2141 }
2142
2143 static time_t
mktime_tzname(struct state * sp,struct tm * tmp,bool setname)2144 mktime_tzname(struct state *sp, struct tm *tmp, bool setname)
2145 {
2146 if (sp)
2147 return time1(tmp, localsub, sp, setname);
2148 else {
2149 gmtcheck();
2150 return time1(tmp, gmtsub, gmtptr, 0);
2151 }
2152 }
2153
2154 #if NETBSD_INSPIRED
2155
2156 time_t
mktime_z(struct state * sp,struct tm * tmp)2157 mktime_z(struct state *sp, struct tm *tmp)
2158 {
2159 return mktime_tzname(sp, tmp, false);
2160 }
2161
2162 #endif
2163
2164 time_t
mktime(struct tm * tmp)2165 mktime(struct tm *tmp)
2166 {
2167 time_t t;
2168 int err = lock();
2169 if (err) {
2170 errno = err;
2171 return -1;
2172 }
2173 tzset_unlocked();
2174 t = mktime_tzname(lclptr, tmp, true);
2175 unlock();
2176 return t;
2177 }
2178
2179 #ifdef STD_INSPIRED
2180
2181 time_t
timelocal(struct tm * tmp)2182 timelocal(struct tm *tmp)
2183 {
2184 if (tmp != NULL)
2185 tmp->tm_isdst = -1; /* in case it wasn't initialized */
2186 return mktime(tmp);
2187 }
2188
2189 time_t
timegm(struct tm * tmp)2190 timegm(struct tm *tmp)
2191 {
2192 return timeoff(tmp, 0);
2193 }
2194
2195 time_t
timeoff(struct tm * tmp,long offset)2196 timeoff(struct tm *tmp, long offset)
2197 {
2198 if (tmp)
2199 tmp->tm_isdst = 0;
2200 gmtcheck();
2201 return time1(tmp, gmtsub, gmtptr, offset);
2202 }
2203
2204 #endif /* defined STD_INSPIRED */
2205
2206 /*
2207 ** XXX--is the below the right way to conditionalize??
2208 */
2209
2210 #ifdef STD_INSPIRED
2211
2212 /*
2213 ** IEEE Std 1003.1-1988 (POSIX) legislates that 536457599
2214 ** shall correspond to "Wed Dec 31 23:59:59 UTC 1986", which
2215 ** is not the case if we are accounting for leap seconds.
2216 ** So, we provide the following conversion routines for use
2217 ** when exchanging timestamps with POSIX conforming systems.
2218 */
2219
2220 static int_fast64_t
leapcorr(struct state const * sp,time_t t)2221 leapcorr(struct state const *sp, time_t t)
2222 {
2223 register struct lsinfo const * lp;
2224 register int i;
2225
2226 i = sp->leapcnt;
2227 while (--i >= 0) {
2228 lp = &sp->lsis[i];
2229 if (t >= lp->ls_trans)
2230 return lp->ls_corr;
2231 }
2232 return 0;
2233 }
2234
2235 NETBSD_INSPIRED_EXTERN time_t ATTRIBUTE_PURE
time2posix_z(struct state * sp,time_t t)2236 time2posix_z(struct state *sp, time_t t)
2237 {
2238 return t - leapcorr(sp, t);
2239 }
2240
2241 time_t
time2posix(time_t t)2242 time2posix(time_t t)
2243 {
2244 int err = lock();
2245 if (err) {
2246 errno = err;
2247 return -1;
2248 }
2249 if (!lcl_is_set)
2250 tzset_unlocked();
2251 if (lclptr)
2252 t = time2posix_z(lclptr, t);
2253 unlock();
2254 return t;
2255 }
2256
2257 NETBSD_INSPIRED_EXTERN time_t ATTRIBUTE_PURE
posix2time_z(struct state * sp,time_t t)2258 posix2time_z(struct state *sp, time_t t)
2259 {
2260 time_t x;
2261 time_t y;
2262 /*
2263 ** For a positive leap second hit, the result
2264 ** is not unique. For a negative leap second
2265 ** hit, the corresponding time doesn't exist,
2266 ** so we return an adjacent second.
2267 */
2268 x = t + leapcorr(sp, t);
2269 y = x - leapcorr(sp, x);
2270 if (y < t) {
2271 do {
2272 x++;
2273 y = x - leapcorr(sp, x);
2274 } while (y < t);
2275 x -= y != t;
2276 } else if (y > t) {
2277 do {
2278 --x;
2279 y = x - leapcorr(sp, x);
2280 } while (y > t);
2281 x += y != t;
2282 }
2283 return x;
2284 }
2285
2286 time_t
posix2time(time_t t)2287 posix2time(time_t t)
2288 {
2289 int err = lock();
2290 if (err) {
2291 errno = err;
2292 return -1;
2293 }
2294 if (!lcl_is_set)
2295 tzset_unlocked();
2296 if (lclptr)
2297 t = posix2time_z(lclptr, t);
2298 unlock();
2299 return t;
2300 }
2301
2302 #endif /* defined STD_INSPIRED */
2303
2304 #ifdef time_tz
2305
2306 /* Convert from the underlying system's time_t to the ersatz time_tz,
2307 which is called 'time_t' in this file. */
2308
2309 time_t
time(time_t * p)2310 time(time_t *p)
2311 {
2312 time_t r = sys_time(0);
2313 if (p)
2314 *p = r;
2315 return r;
2316 }
2317
2318 #endif
2319
2320 // BEGIN android-added
2321
2322 #include <assert.h>
2323 #include <stdint.h>
2324 #include <arpa/inet.h> // For ntohl(3).
2325
__bionic_open_tzdata_path(const char * path_prefix_variable,const char * path_suffix,const char * olson_id)2326 static int __bionic_open_tzdata_path(const char* path_prefix_variable, const char* path_suffix,
2327 const char* olson_id) {
2328 const char* path_prefix = getenv(path_prefix_variable);
2329 if (path_prefix == NULL) {
2330 fprintf(stderr, "%s: %s not set!\n", __FUNCTION__, path_prefix_variable);
2331 return -1;
2332 }
2333 size_t path_length = strlen(path_prefix) + 1 + strlen(path_suffix) + 1;
2334 char* path = malloc(path_length);
2335 if (path == NULL) {
2336 fprintf(stderr, "%s: couldn't allocate %zu-byte path\n", __FUNCTION__, path_length);
2337 return -1;
2338 }
2339 snprintf(path, path_length, "%s/%s", path_prefix, path_suffix);
2340 int fd = TEMP_FAILURE_RETRY(open(path, OPEN_MODE));
2341 if (fd == -1) {
2342 free(path);
2343 return -2; // Distinguish failure to find any data from failure to find a specific id.
2344 }
2345
2346 // byte[12] tzdata_version -- "tzdata2012f\0"
2347 // int index_offset
2348 // int data_offset
2349 // int zonetab_offset
2350 struct bionic_tzdata_header {
2351 char tzdata_version[12];
2352 int32_t index_offset;
2353 int32_t data_offset;
2354 int32_t zonetab_offset;
2355 } header;
2356 memset(&header, 0, sizeof(header));
2357 ssize_t bytes_read = TEMP_FAILURE_RETRY(read(fd, &header, sizeof(header)));
2358 if (bytes_read != sizeof(header)) {
2359 fprintf(stderr, "%s: could not read header of \"%s\": %s\n",
2360 __FUNCTION__, path, (bytes_read == -1) ? strerror(errno) : "short read");
2361 free(path);
2362 close(fd);
2363 return -1;
2364 }
2365
2366 if (strncmp(header.tzdata_version, "tzdata", 6) != 0 || header.tzdata_version[11] != 0) {
2367 fprintf(stderr, "%s: bad magic in \"%s\": \"%.6s\"\n",
2368 __FUNCTION__, path, header.tzdata_version);
2369 free(path);
2370 close(fd);
2371 return -1;
2372 }
2373
2374 #if 0
2375 fprintf(stderr, "version: %s\n", header.tzdata_version);
2376 fprintf(stderr, "index_offset = %d\n", ntohl(header.index_offset));
2377 fprintf(stderr, "data_offset = %d\n", ntohl(header.data_offset));
2378 fprintf(stderr, "zonetab_offset = %d\n", ntohl(header.zonetab_offset));
2379 #endif
2380
2381 if (TEMP_FAILURE_RETRY(lseek(fd, ntohl(header.index_offset), SEEK_SET)) == -1) {
2382 fprintf(stderr, "%s: couldn't seek to index in \"%s\": %s\n",
2383 __FUNCTION__, path, strerror(errno));
2384 free(path);
2385 close(fd);
2386 return -1;
2387 }
2388
2389 off_t specific_zone_offset = -1;
2390 ssize_t index_size = ntohl(header.data_offset) - ntohl(header.index_offset);
2391 char* index = malloc(index_size);
2392 if (index == NULL) {
2393 fprintf(stderr, "%s: couldn't allocate %zd-byte index for \"%s\"\n",
2394 __FUNCTION__, index_size, path);
2395 free(path);
2396 close(fd);
2397 return -1;
2398 }
2399 if (TEMP_FAILURE_RETRY(read(fd, index, index_size)) != index_size) {
2400 fprintf(stderr, "%s: could not read index of \"%s\": %s\n",
2401 __FUNCTION__, path, (bytes_read == -1) ? strerror(errno) : "short read");
2402 free(path);
2403 free(index);
2404 close(fd);
2405 return -1;
2406 }
2407
2408 static const size_t NAME_LENGTH = 40;
2409 struct index_entry_t {
2410 char buf[NAME_LENGTH];
2411 int32_t start;
2412 int32_t length;
2413 int32_t unused; // Was raw GMT offset; always 0 since tzdata2014f (L).
2414 };
2415
2416 size_t id_count = (ntohl(header.data_offset) - ntohl(header.index_offset)) / sizeof(struct index_entry_t);
2417 struct index_entry_t* entry = (struct index_entry_t*) index;
2418 for (size_t i = 0; i < id_count; ++i) {
2419 char this_id[NAME_LENGTH + 1];
2420 memcpy(this_id, entry->buf, NAME_LENGTH);
2421 this_id[NAME_LENGTH] = '\0';
2422
2423 if (strcmp(this_id, olson_id) == 0) {
2424 specific_zone_offset = ntohl(entry->start) + ntohl(header.data_offset);
2425 break;
2426 }
2427
2428 ++entry;
2429 }
2430 free(index);
2431
2432 if (specific_zone_offset == -1) {
2433 free(path);
2434 close(fd);
2435 return -1;
2436 }
2437
2438 if (TEMP_FAILURE_RETRY(lseek(fd, specific_zone_offset, SEEK_SET)) == -1) {
2439 fprintf(stderr, "%s: could not seek to %ld in \"%s\": %s\n",
2440 __FUNCTION__, specific_zone_offset, path, strerror(errno));
2441 free(path);
2442 close(fd);
2443 return -1;
2444 }
2445
2446 // TODO: check that there's TZ_MAGIC at this offset, so we can fall back to the other file if not.
2447
2448 free(path);
2449 return fd;
2450 }
2451
__bionic_open_tzdata(const char * olson_id)2452 static int __bionic_open_tzdata(const char* olson_id) {
2453 int fd = __bionic_open_tzdata_path("ANDROID_DATA", "/misc/zoneinfo/current/tzdata", olson_id);
2454 if (fd < 0) {
2455 fd = __bionic_open_tzdata_path("ANDROID_ROOT", "/usr/share/zoneinfo/tzdata", olson_id);
2456 if (fd == -2) {
2457 // The first thing that 'recovery' does is try to format the current time. It doesn't have
2458 // any tzdata available, so we must not abort here --- doing so breaks the recovery image!
2459 fprintf(stderr, "%s: couldn't find any tzdata when looking for %s!\n", __FUNCTION__, olson_id);
2460 }
2461 }
2462 return fd;
2463 }
2464
2465 // END android-added
2466