Line data Source code
1 : /* Convert timestamp from pg_time_t to struct pg_tm. */
2 :
3 : /*
4 : * This file is in the public domain, so clarified as of
5 : * 1996-06-05 by Arthur David Olson.
6 : *
7 : * IDENTIFICATION
8 : * src/timezone/localtime.c
9 : */
10 :
11 : /*
12 : * Leap second handling from Bradley White.
13 : * POSIX-style TZ environment variable handling from Guy Harris.
14 : */
15 :
16 : /* this file needs to build in both frontend and backend contexts */
17 : #include "c.h"
18 :
19 : #include <fcntl.h>
20 :
21 : #include "datatype/timestamp.h"
22 : #include "pgtz.h"
23 :
24 : #include "private.h"
25 : #include "tzfile.h"
26 :
27 :
28 : #ifndef WILDABBR
29 : /*
30 : * Someone might make incorrect use of a time zone abbreviation:
31 : * 1. They might reference tzname[0] before calling tzset (explicitly
32 : * or implicitly).
33 : * 2. They might reference tzname[1] before calling tzset (explicitly
34 : * or implicitly).
35 : * 3. They might reference tzname[1] after setting to a time zone
36 : * in which Daylight Saving Time is never observed.
37 : * 4. They might reference tzname[0] after setting to a time zone
38 : * in which Standard Time is never observed.
39 : * 5. They might reference tm.tm_zone after calling offtime.
40 : * What's best to do in the above cases is open to debate;
41 : * for now, we just set things up so that in any of the five cases
42 : * WILDABBR is used. Another possibility: initialize tzname[0] to the
43 : * string "tzname[0] used before set", and similarly for the other cases.
44 : * And another: initialize tzname[0] to "ERA", with an explanation in the
45 : * manual page of what this "time zone abbreviation" means (doing this so
46 : * that tzname[0] has the "normal" length of three characters).
47 : */
48 : #define WILDABBR " "
49 : #endif /* !defined WILDABBR */
50 :
51 : static const char wildabbr[] = WILDABBR;
52 :
53 : static const char gmt[] = "GMT";
54 :
55 : /*
56 : * The DST rules to use if a POSIX TZ string has no rules.
57 : * Default to US rules as of 2017-05-07.
58 : * POSIX does not specify the default DST rules;
59 : * for historical reasons, US rules are a common default.
60 : */
61 : #define TZDEFRULESTRING ",M3.2.0,M11.1.0"
62 :
63 : /* structs ttinfo, lsinfo, state have been moved to pgtz.h */
64 :
65 : enum r_type
66 : {
67 : JULIAN_DAY, /* Jn = Julian day */
68 : DAY_OF_YEAR, /* n = day of year */
69 : MONTH_NTH_DAY_OF_WEEK /* Mm.n.d = month, week, day of week */
70 : };
71 :
72 : struct rule
73 : {
74 : enum r_type r_type; /* type of rule */
75 : int r_day; /* day number of rule */
76 : int r_week; /* week number of rule */
77 : int r_mon; /* month number of rule */
78 : int_fast32_t r_time; /* transition time of rule */
79 : };
80 :
81 : /*
82 : * Prototypes for static functions.
83 : */
84 :
85 : static struct pg_tm *gmtsub(pg_time_t const *timep, int_fast32_t offset,
86 : struct pg_tm *tmp);
87 : static bool increment_overflow(int *ip, int j);
88 : static bool increment_overflow_time(pg_time_t *tp, int_fast32_t j);
89 : static int_fast64_t leapcorr(struct state const *sp, pg_time_t t);
90 : static struct pg_tm *timesub(pg_time_t const *timep,
91 : int_fast32_t offset, struct state const *sp,
92 : struct pg_tm *tmp);
93 : static bool typesequiv(struct state const *sp, int a, int b);
94 :
95 :
96 : /*
97 : * Section 4.12.3 of X3.159-1989 requires that
98 : * Except for the strftime function, these functions [asctime,
99 : * ctime, gmtime, localtime] return values in one of two static
100 : * objects: a broken-down time structure and an array of char.
101 : * Thanks to Paul Eggert for noting this.
102 : */
103 :
104 : static struct pg_tm tm;
105 :
106 : /* Initialize *S to a value based on UTOFF, ISDST, and DESIGIDX. */
107 : static void
108 20437 : init_ttinfo(struct ttinfo *s, int_fast32_t utoff, bool isdst, int desigidx)
109 : {
110 20437 : s->tt_utoff = utoff;
111 20437 : s->tt_isdst = isdst;
112 20437 : s->tt_desigidx = desigidx;
113 20437 : s->tt_ttisstd = false;
114 20437 : s->tt_ttisut = false;
115 20437 : }
116 :
117 : static int_fast32_t
118 211493 : detzcode(const char *const codep)
119 : {
120 : int_fast32_t result;
121 : int i;
122 211493 : int_fast32_t one = 1;
123 211493 : int_fast32_t halfmaxval = one << (32 - 2);
124 211493 : int_fast32_t maxval = halfmaxval - 1 + halfmaxval;
125 211493 : int_fast32_t minval = -1 - maxval;
126 :
127 211493 : result = codep[0] & 0x7f;
128 845972 : for (i = 1; i < 4; ++i)
129 634479 : result = (result << 8) | (codep[i] & 0xff);
130 :
131 211493 : if (codep[0] & 0x80)
132 : {
133 : /*
134 : * Do two's-complement negation even on non-two's-complement machines.
135 : * If the result would be minval - 1, return minval.
136 : */
137 35894 : result -= !TWOS_COMPLEMENT(int_fast32_t) && result != 0;
138 35894 : result += minval;
139 : }
140 211493 : return result;
141 : }
142 :
143 : static int_fast64_t
144 879910 : detzcode64(const char *const codep)
145 : {
146 : uint_fast64_t result;
147 : int i;
148 879910 : int_fast64_t one = 1;
149 879910 : int_fast64_t halfmaxval = one << (64 - 2);
150 879910 : int_fast64_t maxval = halfmaxval - 1 + halfmaxval;
151 879910 : int_fast64_t minval = -TWOS_COMPLEMENT(int_fast64_t) - maxval;
152 :
153 879910 : result = codep[0] & 0x7f;
154 7039280 : for (i = 1; i < 8; ++i)
155 6159370 : result = (result << 8) | (codep[i] & 0xff);
156 :
157 879910 : if (codep[0] & 0x80)
158 : {
159 : /*
160 : * Do two's-complement negation even on non-two's-complement machines.
161 : * If the result would be minval - 1, return minval.
162 : */
163 338139 : result -= !TWOS_COMPLEMENT(int_fast64_t) && result != 0;
164 338139 : result += minval;
165 : }
166 879910 : return result;
167 : }
168 :
169 : static bool
170 7279739 : differ_by_repeat(const pg_time_t t1, const pg_time_t t0)
171 : {
172 : if (TYPE_BIT(pg_time_t) - TYPE_SIGNED(pg_time_t) < SECSPERREPEAT_BITS)
173 : return 0;
174 7279739 : return t1 - t0 == SECSPERREPEAT;
175 : }
176 :
177 : /* Input buffer for data read from a compiled tz file. */
178 : union input_buffer
179 : {
180 : /* The first part of the buffer, interpreted as a header. */
181 : struct tzhead tzhead;
182 :
183 : /* The entire buffer. */
184 : char buf[2 * sizeof(struct tzhead) + 2 * sizeof(struct state)
185 : + 4 * TZ_MAX_TIMES];
186 : };
187 :
188 : /* Local storage needed for 'tzloadbody'. */
189 : union local_storage
190 : {
191 : /* The results of analyzing the file's contents after it is opened. */
192 : struct file_analysis
193 : {
194 : /* The input buffer. */
195 : union input_buffer u;
196 :
197 : /* A temporary state used for parsing a TZ string in the file. */
198 : struct state st;
199 : } u;
200 :
201 : /* We don't need the "fullname" member */
202 : };
203 :
204 : /*
205 : * Load tz data from the file named NAME into *SP. Read extended
206 : * format if DOEXTEND. Use *LSP for temporary storage. Return 0 on
207 : * success, an errno value on failure.
208 : * PG: If "canonname" is not NULL, then on success the canonical spelling of
209 : * given name is stored there (the buffer must be > TZ_STRLEN_MAX bytes!).
210 : */
211 : static int
212 12518 : tzloadbody(char const *name, char *canonname, struct state *sp, bool doextend,
213 : union local_storage *lsp)
214 : {
215 : int i;
216 : int fid;
217 : int stored;
218 : ssize_t nread;
219 12518 : union input_buffer *up = &lsp->u.u;
220 12518 : int tzheadsize = sizeof(struct tzhead);
221 :
222 12518 : sp->goback = sp->goahead = false;
223 :
224 12518 : if (!name)
225 : {
226 0 : name = TZDEFAULT;
227 0 : if (!name)
228 0 : return EINVAL;
229 : }
230 :
231 12518 : if (name[0] == ':')
232 0 : ++name;
233 :
234 12518 : fid = pg_open_tzfile(name, canonname);
235 12518 : if (fid < 0)
236 289 : return ENOENT; /* pg_open_tzfile may not set errno */
237 :
238 12229 : nread = read(fid, up->buf, sizeof up->buf);
239 12229 : if (nread < tzheadsize)
240 : {
241 0 : int err = nread < 0 ? errno : EINVAL;
242 :
243 0 : close(fid);
244 0 : return err;
245 : }
246 12229 : if (close(fid) < 0)
247 0 : return errno;
248 36687 : for (stored = 4; stored <= 8; stored *= 2)
249 : {
250 24458 : int_fast32_t ttisstdcnt = detzcode(up->tzhead.tzh_ttisstdcnt);
251 24458 : int_fast32_t ttisutcnt = detzcode(up->tzhead.tzh_ttisutcnt);
252 24458 : int_fast64_t prevtr = 0;
253 24458 : int_fast32_t prevcorr = 0;
254 24458 : int_fast32_t leapcnt = detzcode(up->tzhead.tzh_leapcnt);
255 24458 : int_fast32_t timecnt = detzcode(up->tzhead.tzh_timecnt);
256 24458 : int_fast32_t typecnt = detzcode(up->tzhead.tzh_typecnt);
257 24458 : int_fast32_t charcnt = detzcode(up->tzhead.tzh_charcnt);
258 24458 : char const *p = up->buf + tzheadsize;
259 :
260 : /*
261 : * Although tzfile(5) currently requires typecnt to be nonzero,
262 : * support future formats that may allow zero typecnt in files that
263 : * have a TZ string and no transitions.
264 : */
265 48916 : if (!(0 <= leapcnt && leapcnt < TZ_MAX_LEAPS
266 24458 : && 0 <= typecnt && typecnt < TZ_MAX_TYPES
267 24458 : && 0 <= timecnt && timecnt < TZ_MAX_TIMES
268 24458 : && 0 <= charcnt && charcnt < TZ_MAX_CHARS
269 24458 : && (ttisstdcnt == typecnt || ttisstdcnt == 0)
270 24458 : && (ttisutcnt == typecnt || ttisutcnt == 0)))
271 0 : return EINVAL;
272 24458 : if (nread
273 : < (tzheadsize /* struct tzhead */
274 24458 : + timecnt * stored /* ats */
275 24458 : + timecnt /* types */
276 24458 : + typecnt * 6 /* ttinfos */
277 24458 : + charcnt /* chars */
278 24458 : + leapcnt * (stored + 4) /* lsinfos */
279 24458 : + ttisstdcnt /* ttisstds */
280 24458 : + ttisutcnt)) /* ttisuts */
281 0 : return EINVAL;
282 24458 : sp->leapcnt = leapcnt;
283 24458 : sp->timecnt = timecnt;
284 24458 : sp->typecnt = typecnt;
285 24458 : sp->charcnt = charcnt;
286 :
287 : /*
288 : * Read transitions, discarding those out of pg_time_t range. But
289 : * pretend the last transition before TIME_T_MIN occurred at
290 : * TIME_T_MIN.
291 : */
292 24458 : timecnt = 0;
293 904368 : for (i = 0; i < sp->timecnt; ++i)
294 : {
295 879910 : int_fast64_t at
296 879910 : = stored == 4 ? detzcode(p) : detzcode64(p);
297 :
298 879910 : sp->types[i] = at <= TIME_T_MAX;
299 879910 : if (sp->types[i])
300 : {
301 879910 : pg_time_t attime
302 : = ((TYPE_SIGNED(pg_time_t) ? at < TIME_T_MIN : at < 0)
303 : ? TIME_T_MIN : at);
304 :
305 879910 : if (timecnt && attime <= sp->ats[timecnt - 1])
306 : {
307 0 : if (attime < sp->ats[timecnt - 1])
308 0 : return EINVAL;
309 0 : sp->types[i - 1] = 0;
310 0 : timecnt--;
311 : }
312 879910 : sp->ats[timecnt++] = attime;
313 : }
314 879910 : p += stored;
315 : }
316 :
317 24458 : timecnt = 0;
318 904368 : for (i = 0; i < sp->timecnt; ++i)
319 : {
320 879910 : unsigned char typ = *p++;
321 :
322 879910 : if (sp->typecnt <= typ)
323 0 : return EINVAL;
324 879910 : if (sp->types[i])
325 879910 : sp->types[timecnt++] = typ;
326 : }
327 24458 : sp->timecnt = timecnt;
328 89203 : for (i = 0; i < sp->typecnt; ++i)
329 : {
330 : struct ttinfo *ttisp;
331 : unsigned char isdst,
332 : desigidx;
333 :
334 64745 : ttisp = &sp->ttis[i];
335 64745 : ttisp->tt_utoff = detzcode(p);
336 64745 : p += 4;
337 64745 : isdst = *p++;
338 64745 : if (!(isdst < 2))
339 0 : return EINVAL;
340 64745 : ttisp->tt_isdst = isdst;
341 64745 : desigidx = *p++;
342 64745 : if (!(desigidx < sp->charcnt))
343 0 : return EINVAL;
344 64745 : ttisp->tt_desigidx = desigidx;
345 : }
346 243068 : for (i = 0; i < sp->charcnt; ++i)
347 218610 : sp->chars[i] = *p++;
348 24458 : sp->chars[i] = '\0'; /* ensure '\0' at end */
349 :
350 : /* Read leap seconds, discarding those out of pg_time_t range. */
351 24458 : leapcnt = 0;
352 24458 : for (i = 0; i < sp->leapcnt; ++i)
353 : {
354 0 : int_fast64_t tr = stored == 4 ? detzcode(p) : detzcode64(p);
355 0 : int_fast32_t corr = detzcode(p + stored);
356 :
357 0 : p += stored + 4;
358 : /* Leap seconds cannot occur before the Epoch. */
359 0 : if (tr < 0)
360 0 : return EINVAL;
361 : if (tr <= TIME_T_MAX)
362 : {
363 : /*
364 : * Leap seconds cannot occur more than once per UTC month, and
365 : * UTC months are at least 28 days long (minus 1 second for a
366 : * negative leap second). Each leap second's correction must
367 : * differ from the previous one's by 1 second.
368 : */
369 0 : if (tr - prevtr < 28 * SECSPERDAY - 1
370 0 : || (corr != prevcorr - 1 && corr != prevcorr + 1))
371 0 : return EINVAL;
372 0 : sp->lsis[leapcnt].ls_trans = prevtr = tr;
373 0 : sp->lsis[leapcnt].ls_corr = prevcorr = corr;
374 0 : leapcnt++;
375 : }
376 : }
377 24458 : sp->leapcnt = leapcnt;
378 :
379 89203 : for (i = 0; i < sp->typecnt; ++i)
380 : {
381 : struct ttinfo *ttisp;
382 :
383 64745 : ttisp = &sp->ttis[i];
384 64745 : if (ttisstdcnt == 0)
385 64745 : ttisp->tt_ttisstd = false;
386 : else
387 : {
388 0 : if (*p != true && *p != false)
389 0 : return EINVAL;
390 0 : ttisp->tt_ttisstd = *p++;
391 : }
392 : }
393 89203 : for (i = 0; i < sp->typecnt; ++i)
394 : {
395 : struct ttinfo *ttisp;
396 :
397 64745 : ttisp = &sp->ttis[i];
398 64745 : if (ttisutcnt == 0)
399 64745 : ttisp->tt_ttisut = false;
400 : else
401 : {
402 0 : if (*p != true && *p != false)
403 0 : return EINVAL;
404 0 : ttisp->tt_ttisut = *p++;
405 : }
406 : }
407 :
408 : /*
409 : * If this is an old file, we're done.
410 : */
411 24458 : if (up->tzhead.tzh_version[0] == '\0')
412 0 : break;
413 24458 : nread -= p - up->buf;
414 24458 : memmove(up->buf, p, nread);
415 : }
416 12229 : if (doextend && nread > 2 &&
417 12229 : up->buf[0] == '\n' && up->buf[nread - 1] == '\n' &&
418 12229 : sp->typecnt + 2 <= TZ_MAX_TYPES)
419 : {
420 12229 : struct state *ts = &lsp->u.st;
421 :
422 12229 : up->buf[nread - 1] = '\0';
423 12229 : if (tzparse(&up->buf[1], ts, false))
424 : {
425 :
426 : /*
427 : * Attempt to reuse existing abbreviations. Without this,
428 : * America/Anchorage would be right on the edge after 2037 when
429 : * TZ_MAX_CHARS is 50, as sp->charcnt equals 40 (for LMT AST AWT
430 : * APT AHST AHDT YST AKDT AKST) and ts->charcnt equals 10 (for
431 : * AKST AKDT). Reusing means sp->charcnt can stay 40 in this
432 : * example.
433 : */
434 12229 : int gotabbr = 0;
435 12229 : int charcnt = sp->charcnt;
436 :
437 31141 : for (i = 0; i < ts->typecnt; i++)
438 : {
439 18912 : char *tsabbr = ts->chars + ts->ttis[i].tt_desigidx;
440 : int j;
441 :
442 157447 : for (j = 0; j < charcnt; j++)
443 157407 : if (strcmp(sp->chars + j, tsabbr) == 0)
444 : {
445 18872 : ts->ttis[i].tt_desigidx = j;
446 18872 : gotabbr++;
447 18872 : break;
448 : }
449 18912 : if (!(j < charcnt))
450 : {
451 40 : int tsabbrlen = strlen(tsabbr);
452 :
453 40 : if (j + tsabbrlen < TZ_MAX_CHARS)
454 : {
455 40 : strcpy(sp->chars + j, tsabbr);
456 40 : charcnt = j + tsabbrlen + 1;
457 40 : ts->ttis[i].tt_desigidx = j;
458 40 : gotabbr++;
459 : }
460 : }
461 : }
462 12229 : if (gotabbr == ts->typecnt)
463 : {
464 12229 : sp->charcnt = charcnt;
465 :
466 : /*
467 : * Ignore any trailing, no-op transitions generated by zic as
468 : * they don't help here and can run afoul of bugs in zic 2016j
469 : * or earlier.
470 : */
471 12229 : while (1 < sp->timecnt
472 12249 : && (sp->types[sp->timecnt - 1]
473 9974 : == sp->types[sp->timecnt - 2]))
474 20 : sp->timecnt--;
475 :
476 3181046 : for (i = 0; i < ts->timecnt; i++)
477 3175500 : if (sp->timecnt == 0
478 6351000 : || (sp->ats[sp->timecnt - 1]
479 3175500 : < ts->ats[i] + leapcorr(sp, ts->ats[i])))
480 : break;
481 12229 : while (i < ts->timecnt
482 10209412 : && sp->timecnt < TZ_MAX_TIMES)
483 : {
484 10197183 : sp->ats[sp->timecnt]
485 10197183 : = ts->ats[i] + leapcorr(sp, ts->ats[i]);
486 10197183 : sp->types[sp->timecnt] = (sp->typecnt
487 10197183 : + ts->types[i]);
488 10197183 : sp->timecnt++;
489 10197183 : i++;
490 : }
491 31141 : for (i = 0; i < ts->typecnt; i++)
492 18912 : sp->ttis[sp->typecnt++] = ts->ttis[i];
493 : }
494 : }
495 : }
496 12229 : if (sp->typecnt == 0)
497 0 : return EINVAL;
498 12229 : if (sp->timecnt > 1)
499 : {
500 11076623 : for (i = 1; i < sp->timecnt; ++i)
501 15642792 : if (typesequiv(sp, sp->types[i], sp->types[0]) &&
502 4576123 : differ_by_repeat(sp->ats[i], sp->ats[0]))
503 : {
504 0 : sp->goback = true;
505 0 : break;
506 : }
507 5456131 : for (i = sp->timecnt - 2; i >= 0; --i)
508 5452860 : if (typesequiv(sp, sp->types[sp->timecnt - 1],
509 8156476 : sp->types[i]) &&
510 2703616 : differ_by_repeat(sp->ats[sp->timecnt - 1],
511 : sp->ats[i]))
512 : {
513 6683 : sp->goahead = true;
514 6683 : break;
515 : }
516 : }
517 :
518 : /*
519 : * Infer sp->defaulttype from the data. Although this default type is
520 : * always zero for data from recent tzdb releases, things are trickier for
521 : * data from tzdb 2018e or earlier.
522 : *
523 : * The first set of heuristics work around bugs in 32-bit data generated
524 : * by tzdb 2013c or earlier. The workaround is for zones like
525 : * Australia/Macquarie where timestamps before the first transition have a
526 : * time type that is not the earliest standard-time type. See:
527 : * https://mm.icann.org/pipermail/tz/2013-May/019368.html
528 : */
529 :
530 : /*
531 : * If type 0 is unused in transitions, it's the type to use for early
532 : * times.
533 : */
534 11022168 : for (i = 0; i < sp->timecnt; ++i)
535 11010103 : if (sp->types[i] == 0)
536 164 : break;
537 12229 : i = i < sp->timecnt ? -1 : 0;
538 :
539 : /*
540 : * Absent the above, if there are transition times and the first
541 : * transition is to a daylight time find the standard type less than and
542 : * closest to the type of the first transition.
543 : */
544 12229 : if (i < 0 && sp->timecnt > 0 && sp->ttis[sp->types[0]].tt_isdst)
545 : {
546 0 : i = sp->types[0];
547 0 : while (--i >= 0)
548 0 : if (!sp->ttis[i].tt_isdst)
549 0 : break;
550 : }
551 :
552 : /*
553 : * The next heuristics are for data generated by tzdb 2018e or earlier,
554 : * for zones like EST5EDT where the first transition is to DST.
555 : */
556 :
557 : /*
558 : * If no result yet, find the first standard type. If there is none, punt
559 : * to type zero.
560 : */
561 12229 : if (i < 0)
562 : {
563 164 : i = 0;
564 164 : while (sp->ttis[i].tt_isdst)
565 0 : if (++i >= sp->typecnt)
566 : {
567 0 : i = 0;
568 0 : break;
569 : }
570 : }
571 :
572 : /*
573 : * A simple 'sp->defaulttype = 0;' would suffice here if we didn't have to
574 : * worry about 2018e-or-earlier data. Even simpler would be to remove the
575 : * defaulttype member and just use 0 in its place.
576 : */
577 12229 : sp->defaulttype = i;
578 :
579 12229 : return 0;
580 : }
581 :
582 : /*
583 : * Load tz data from the file named NAME into *SP. Read extended
584 : * format if DOEXTEND. Return 0 on success, an errno value on failure.
585 : * PG: If "canonname" is not NULL, then on success the canonical spelling of
586 : * given name is stored there (the buffer must be > TZ_STRLEN_MAX bytes!).
587 : */
588 : int
589 12518 : tzload(char const *name, char *canonname, struct state *sp, bool doextend)
590 : {
591 12518 : union local_storage *lsp = malloc(sizeof *lsp);
592 :
593 12518 : if (!lsp)
594 0 : return errno;
595 : else
596 : {
597 12518 : int err = tzloadbody(name, canonname, sp, doextend, lsp);
598 :
599 12518 : free(lsp);
600 12518 : return err;
601 : }
602 : }
603 :
604 : static bool
605 16519529 : typesequiv(const struct state *sp, int a, int b)
606 : {
607 : bool result;
608 :
609 16519529 : if (sp == NULL ||
610 16519529 : a < 0 || a >= sp->typecnt ||
611 16519529 : b < 0 || b >= sp->typecnt)
612 0 : result = false;
613 : else
614 : {
615 16519529 : const struct ttinfo *ap = &sp->ttis[a];
616 16519529 : const struct ttinfo *bp = &sp->ttis[b];
617 :
618 16519529 : result = (ap->tt_utoff == bp->tt_utoff
619 7349371 : && ap->tt_isdst == bp->tt_isdst
620 7297009 : && ap->tt_ttisstd == bp->tt_ttisstd
621 7297009 : && ap->tt_ttisut == bp->tt_ttisut
622 23868900 : && (strcmp(&sp->chars[ap->tt_desigidx],
623 7297009 : &sp->chars[bp->tt_desigidx])
624 : == 0));
625 : }
626 16519529 : return result;
627 : }
628 :
629 : static const int mon_lengths[2][MONSPERYEAR] = {
630 : {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31},
631 : {31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}
632 : };
633 :
634 : static const int year_lengths[2] = {
635 : DAYSPERNYEAR, DAYSPERLYEAR
636 : };
637 :
638 : /*
639 : * Given a pointer into a timezone string, scan until a character that is not
640 : * a valid character in a time zone abbreviation is found.
641 : * Return a pointer to that character.
642 : */
643 :
644 : static const char *
645 16543 : getzname(const char *strp)
646 : {
647 : char c;
648 :
649 67979 : while ((c = *strp) != '\0' && !is_digit(c) && c != ',' && c != '-' &&
650 : c != '+')
651 51436 : ++strp;
652 16543 : return strp;
653 : }
654 :
655 : /*
656 : * Given a pointer into an extended timezone string, scan until the ending
657 : * delimiter of the time zone abbreviation is located.
658 : * Return a pointer to the delimiter.
659 : *
660 : * As with getzname above, the legal character set is actually quite
661 : * restricted, with other characters producing undefined results.
662 : * We don't do any checking here; checking is done later in common-case code.
663 : */
664 :
665 : static const char *
666 2671 : getqzname(const char *strp, const int delim)
667 : {
668 : int c;
669 :
670 11076 : while ((c = *strp) != '\0' && c != delim)
671 8405 : ++strp;
672 2671 : return strp;
673 : }
674 :
675 : /*
676 : * Given a pointer into a timezone string, extract a number from that string.
677 : * Check that the number is within a specified range; if it is not, return
678 : * NULL.
679 : * Otherwise, return a pointer to the first character not part of the number.
680 : */
681 :
682 : static const char *
683 54566 : getnum(const char *strp, int *const nump, const int min, const int max)
684 : {
685 : char c;
686 : int num;
687 :
688 54566 : if (strp == NULL || !is_digit(c = *strp))
689 0 : return NULL;
690 54566 : num = 0;
691 : do
692 : {
693 62697 : num = num * 10 + (c - '0');
694 62697 : if (num > max)
695 0 : return NULL; /* illegal value */
696 62697 : c = *++strp;
697 62697 : } while (is_digit(c));
698 54566 : if (num < min)
699 0 : return NULL; /* illegal value */
700 54566 : *nump = num;
701 54566 : return strp;
702 : }
703 :
704 : /*
705 : * Given a pointer into a timezone string, extract a number of seconds,
706 : * in hh[:mm[:ss]] form, from the string.
707 : * If any error occurs, return NULL.
708 : * Otherwise, return a pointer to the first character not part of the number
709 : * of seconds.
710 : */
711 :
712 : static const char *
713 14024 : getsecs(const char *strp, int_fast32_t *const secsp)
714 : {
715 : int num;
716 :
717 : /*
718 : * 'HOURSPERDAY * DAYSPERWEEK - 1' allows quasi-Posix rules like
719 : * "M10.4.6/26", which does not conform to Posix, but which specifies the
720 : * equivalent of "02:00 on the first Sunday on or after 23 Oct".
721 : */
722 14024 : strp = getnum(strp, &num, 0, HOURSPERDAY * DAYSPERWEEK - 1);
723 14024 : if (strp == NULL)
724 0 : return NULL;
725 14024 : *secsp = num * (int_fast32_t) SECSPERHOUR;
726 14024 : if (*strp == ':')
727 : {
728 366 : ++strp;
729 366 : strp = getnum(strp, &num, 0, MINSPERHOUR - 1);
730 366 : if (strp == NULL)
731 0 : return NULL;
732 366 : *secsp += num * SECSPERMIN;
733 366 : if (*strp == ':')
734 : {
735 0 : ++strp;
736 : /* 'SECSPERMIN' allows for leap seconds. */
737 0 : strp = getnum(strp, &num, 0, SECSPERMIN);
738 0 : if (strp == NULL)
739 0 : return NULL;
740 0 : *secsp += num;
741 : }
742 : }
743 14024 : return strp;
744 : }
745 :
746 : /*
747 : * Given a pointer into a timezone string, extract an offset, in
748 : * [+-]hh[:mm[:ss]] form, from the string.
749 : * If any error occurs, return NULL.
750 : * Otherwise, return a pointer to the first character not part of the time.
751 : */
752 :
753 : static const char *
754 14024 : getoffset(const char *strp, int_fast32_t *const offsetp)
755 : {
756 14024 : bool neg = false;
757 :
758 14024 : if (*strp == '-')
759 : {
760 3387 : neg = true;
761 3387 : ++strp;
762 : }
763 10637 : else if (*strp == '+')
764 85 : ++strp;
765 14024 : strp = getsecs(strp, offsetp);
766 14024 : if (strp == NULL)
767 0 : return NULL; /* illegal time */
768 14024 : if (neg)
769 3387 : *offsetp = -*offsetp;
770 14024 : return strp;
771 : }
772 :
773 : /*
774 : * Given a pointer into a timezone string, extract a rule in the form
775 : * date[/time]. See POSIX section 8 for the format of "date" and "time".
776 : * If a valid rule is not found, return NULL.
777 : * Otherwise, return a pointer to the first character not part of the rule.
778 : */
779 :
780 : static const char *
781 13392 : getrule(const char *strp, struct rule *const rulep)
782 : {
783 13392 : if (*strp == 'J')
784 : {
785 : /*
786 : * Julian day.
787 : */
788 0 : rulep->r_type = JULIAN_DAY;
789 0 : ++strp;
790 0 : strp = getnum(strp, &rulep->r_day, 1, DAYSPERNYEAR);
791 : }
792 13392 : else if (*strp == 'M')
793 : {
794 : /*
795 : * Month, week, day.
796 : */
797 13392 : rulep->r_type = MONTH_NTH_DAY_OF_WEEK;
798 13392 : ++strp;
799 13392 : strp = getnum(strp, &rulep->r_mon, 1, MONSPERYEAR);
800 13392 : if (strp == NULL)
801 0 : return NULL;
802 13392 : if (*strp++ != '.')
803 0 : return NULL;
804 13392 : strp = getnum(strp, &rulep->r_week, 1, 5);
805 13392 : if (strp == NULL)
806 0 : return NULL;
807 13392 : if (*strp++ != '.')
808 0 : return NULL;
809 13392 : strp = getnum(strp, &rulep->r_day, 0, DAYSPERWEEK - 1);
810 : }
811 0 : else if (is_digit(*strp))
812 : {
813 : /*
814 : * Day of year.
815 : */
816 0 : rulep->r_type = DAY_OF_YEAR;
817 0 : strp = getnum(strp, &rulep->r_day, 0, DAYSPERLYEAR - 1);
818 : }
819 : else
820 0 : return NULL; /* invalid format */
821 13392 : if (strp == NULL)
822 0 : return NULL;
823 13392 : if (*strp == '/')
824 : {
825 : /*
826 : * Time specified.
827 : */
828 1520 : ++strp;
829 1520 : strp = getoffset(strp, &rulep->r_time);
830 : }
831 : else
832 11872 : rulep->r_time = 2 * SECSPERHOUR; /* default = 2:00:00 */
833 13392 : return strp;
834 : }
835 :
836 : /*
837 : * Given a year, a rule, and the offset from UT at the time that rule takes
838 : * effect, calculate the year-relative time that rule takes effect.
839 : */
840 :
841 : static int_fast32_t
842 13405392 : transtime(const int year, const struct rule *const rulep,
843 : const int_fast32_t offset)
844 : {
845 : bool leapyear;
846 : int_fast32_t value;
847 : int i;
848 : int d,
849 : m1,
850 : yy0,
851 : yy1,
852 : yy2,
853 : dow;
854 :
855 13405392 : INITIALIZE(value);
856 13405392 : leapyear = isleap(year);
857 13405392 : switch (rulep->r_type)
858 : {
859 :
860 0 : case JULIAN_DAY:
861 :
862 : /*
863 : * Jn - Julian day, 1 == January 1, 60 == March 1 even in leap
864 : * years. In non-leap years, or if the day number is 59 or less,
865 : * just add SECSPERDAY times the day number-1 to the time of
866 : * January 1, midnight, to get the day.
867 : */
868 0 : value = (rulep->r_day - 1) * SECSPERDAY;
869 0 : if (leapyear && rulep->r_day >= 60)
870 0 : value += SECSPERDAY;
871 0 : break;
872 :
873 0 : case DAY_OF_YEAR:
874 :
875 : /*
876 : * n - day of year. Just add SECSPERDAY times the day number to
877 : * the time of January 1, midnight, to get the day.
878 : */
879 0 : value = rulep->r_day * SECSPERDAY;
880 0 : break;
881 :
882 13405392 : case MONTH_NTH_DAY_OF_WEEK:
883 :
884 : /*
885 : * Mm.n.d - nth "dth day" of month m.
886 : */
887 :
888 : /*
889 : * Use Zeller's Congruence to get day-of-week of first day of
890 : * month.
891 : */
892 13405392 : m1 = (rulep->r_mon + 9) % 12 + 1;
893 13405392 : yy0 = (rulep->r_mon <= 2) ? (year - 1) : year;
894 13405392 : yy1 = yy0 / 100;
895 13405392 : yy2 = yy0 % 100;
896 13405392 : dow = ((26 * m1 - 2) / 10 +
897 13405392 : 1 + yy2 + yy2 / 4 + yy1 / 4 - 2 * yy1) % 7;
898 13405392 : if (dow < 0)
899 2520009 : dow += DAYSPERWEEK;
900 :
901 : /*
902 : * "dow" is the day-of-week of the first day of the month. Get the
903 : * day-of-month (zero-origin) of the first "dow" day of the month.
904 : */
905 13405392 : d = rulep->r_day - dow;
906 13405392 : if (d < 0)
907 11308901 : d += DAYSPERWEEK;
908 25068337 : for (i = 1; i < rulep->r_week; ++i)
909 : {
910 12662650 : if (d + DAYSPERWEEK >=
911 12662650 : mon_lengths[leapyear][rulep->r_mon - 1])
912 999705 : break;
913 11662945 : d += DAYSPERWEEK;
914 : }
915 :
916 : /*
917 : * "d" is the day-of-month (zero-origin) of the day we want.
918 : */
919 13405392 : value = d * SECSPERDAY;
920 92883791 : for (i = 0; i < rulep->r_mon - 1; ++i)
921 79478399 : value += mon_lengths[leapyear][i] * SECSPERDAY;
922 13405392 : break;
923 : }
924 :
925 : /*
926 : * "value" is the year-relative time of 00:00:00 UT on the day in
927 : * question. To get the year-relative time of the specified local time on
928 : * that day, add the transition time and the current offset from UT.
929 : */
930 13405392 : return value + rulep->r_time + offset;
931 : }
932 :
933 : /*
934 : * Given a POSIX section 8-style TZ string, fill in the rule tables as
935 : * appropriate.
936 : * Returns true on success, false on failure.
937 : */
938 : bool
939 13809 : tzparse(const char *name, struct state *sp, bool lastditch)
940 : {
941 : const char *stdname;
942 13809 : const char *dstname = NULL;
943 : size_t stdlen;
944 : size_t dstlen;
945 : size_t charcnt;
946 : int_fast32_t stdoffset;
947 : int_fast32_t dstoffset;
948 : char *cp;
949 : bool load_ok;
950 :
951 13809 : stdname = name;
952 13809 : if (lastditch)
953 : {
954 : /* Unlike IANA, don't assume name is exactly "GMT" */
955 1291 : stdlen = strlen(name); /* length of standard zone name */
956 1291 : name += stdlen;
957 1291 : stdoffset = 0;
958 : }
959 : else
960 : {
961 12518 : if (*name == '<')
962 : {
963 2509 : name++;
964 2509 : stdname = name;
965 2509 : name = getqzname(name, '>');
966 2509 : if (*name != '>')
967 0 : return false;
968 2509 : stdlen = name - stdname;
969 2509 : name++;
970 : }
971 : else
972 : {
973 10009 : name = getzname(name);
974 10009 : stdlen = name - stdname;
975 : }
976 12518 : if (*name == '\0') /* we allow empty STD abbrev, unlike IANA */
977 68 : return false;
978 12450 : name = getoffset(name, &stdoffset);
979 12450 : if (name == NULL)
980 0 : return false;
981 : }
982 13741 : charcnt = stdlen + 1;
983 13741 : if (sizeof sp->chars < charcnt)
984 0 : return false;
985 :
986 : /*
987 : * The IANA code always tries to tzload(TZDEFRULES) here. We do not want
988 : * to do that; it would be bad news in the lastditch case, where we can't
989 : * assume pg_open_tzfile() is sane yet. Moreover, if we did load it and
990 : * it contains leap-second-dependent info, that would cause problems too.
991 : * Finally, IANA has deprecated the TZDEFRULES feature, so it presumably
992 : * will die at some point. Desupporting it now seems like good
993 : * future-proofing.
994 : */
995 13741 : load_ok = false;
996 13741 : sp->goback = sp->goahead = false; /* simulate failed tzload() */
997 13741 : sp->leapcnt = 0; /* intentionally assume no leap seconds */
998 :
999 13741 : if (*name != '\0')
1000 : {
1001 6696 : if (*name == '<')
1002 : {
1003 162 : dstname = ++name;
1004 162 : name = getqzname(name, '>');
1005 162 : if (*name != '>')
1006 0 : return false;
1007 162 : dstlen = name - dstname;
1008 162 : name++;
1009 : }
1010 : else
1011 : {
1012 6534 : dstname = name;
1013 6534 : name = getzname(name);
1014 6534 : dstlen = name - dstname; /* length of DST abbr. */
1015 : }
1016 6696 : if (!dstlen)
1017 0 : return false;
1018 6696 : charcnt += dstlen + 1;
1019 6696 : if (sizeof sp->chars < charcnt)
1020 0 : return false;
1021 6696 : if (*name != '\0' && *name != ',' && *name != ';')
1022 : {
1023 54 : name = getoffset(name, &dstoffset);
1024 54 : if (name == NULL)
1025 0 : return false;
1026 : }
1027 : else
1028 6642 : dstoffset = stdoffset - SECSPERHOUR;
1029 6696 : if (*name == '\0' && !load_ok)
1030 4 : name = TZDEFRULESTRING;
1031 6696 : if (*name == ',' || *name == ';')
1032 6696 : {
1033 : struct rule start;
1034 : struct rule end;
1035 : int year;
1036 : int yearlim;
1037 : int timecnt;
1038 : pg_time_t janfirst;
1039 6696 : int_fast32_t janoffset = 0;
1040 : int yearbeg;
1041 :
1042 6696 : ++name;
1043 6696 : if ((name = getrule(name, &start)) == NULL)
1044 0 : return false;
1045 6696 : if (*name++ != ',')
1046 0 : return false;
1047 6696 : if ((name = getrule(name, &end)) == NULL)
1048 0 : return false;
1049 6696 : if (*name != '\0')
1050 0 : return false;
1051 6696 : sp->typecnt = 2; /* standard time and DST */
1052 :
1053 : /*
1054 : * Two transitions per year, from EPOCH_YEAR forward.
1055 : */
1056 6696 : init_ttinfo(&sp->ttis[0], -stdoffset, false, 0);
1057 6696 : init_ttinfo(&sp->ttis[1], -dstoffset, true, stdlen + 1);
1058 6696 : sp->defaulttype = 0;
1059 6696 : timecnt = 0;
1060 6696 : janfirst = 0;
1061 6696 : yearbeg = EPOCH_YEAR;
1062 :
1063 : do
1064 : {
1065 1339200 : int_fast32_t yearsecs
1066 1339200 : = year_lengths[isleap(yearbeg - 1)] * SECSPERDAY;
1067 :
1068 1339200 : yearbeg--;
1069 1339200 : if (increment_overflow_time(&janfirst, -yearsecs))
1070 : {
1071 0 : janoffset = -yearsecs;
1072 0 : break;
1073 : }
1074 1339200 : } while (EPOCH_YEAR - YEARSPERREPEAT / 2 < yearbeg);
1075 :
1076 6696 : yearlim = yearbeg + YEARSPERREPEAT + 1;
1077 6702696 : for (year = yearbeg; year < yearlim; year++)
1078 : {
1079 : int_fast32_t
1080 6702696 : starttime = transtime(year, &start, stdoffset),
1081 6702696 : endtime = transtime(year, &end, dstoffset);
1082 : int_fast32_t
1083 6702696 : yearsecs = (year_lengths[isleap(year)]
1084 : * SECSPERDAY);
1085 6702696 : bool reversed = endtime < starttime;
1086 :
1087 6702696 : if (reversed)
1088 : {
1089 306306 : int_fast32_t swap = starttime;
1090 :
1091 306306 : starttime = endtime;
1092 306306 : endtime = swap;
1093 : }
1094 6702696 : if (reversed
1095 6396390 : || (starttime < endtime
1096 6396390 : && (endtime - starttime
1097 : < (yearsecs
1098 6396390 : + (stdoffset - dstoffset)))))
1099 : {
1100 6702696 : if (TZ_MAX_TIMES - 2 < timecnt)
1101 6696 : break;
1102 6696000 : sp->ats[timecnt] = janfirst;
1103 6696000 : if (!increment_overflow_time
1104 : (&sp->ats[timecnt],
1105 : janoffset + starttime))
1106 6696000 : sp->types[timecnt++] = !reversed;
1107 6696000 : sp->ats[timecnt] = janfirst;
1108 6696000 : if (!increment_overflow_time
1109 : (&sp->ats[timecnt],
1110 : janoffset + endtime))
1111 : {
1112 6696000 : sp->types[timecnt++] = reversed;
1113 6696000 : yearlim = year + YEARSPERREPEAT + 1;
1114 : }
1115 : }
1116 6696000 : if (increment_overflow_time
1117 : (&janfirst, janoffset + yearsecs))
1118 0 : break;
1119 6696000 : janoffset = 0;
1120 : }
1121 6696 : sp->timecnt = timecnt;
1122 6696 : if (!timecnt)
1123 : {
1124 0 : sp->ttis[0] = sp->ttis[1];
1125 0 : sp->typecnt = 1; /* Perpetual DST. */
1126 : }
1127 6696 : else if (YEARSPERREPEAT < year - yearbeg)
1128 6696 : sp->goback = sp->goahead = true;
1129 : }
1130 : else
1131 : {
1132 : int_fast32_t theirstdoffset;
1133 : int_fast32_t theirdstoffset;
1134 : int_fast32_t theiroffset;
1135 : bool isdst;
1136 : int i;
1137 : int j;
1138 :
1139 0 : if (*name != '\0')
1140 0 : return false;
1141 :
1142 : /*
1143 : * Initial values of theirstdoffset and theirdstoffset.
1144 : */
1145 0 : theirstdoffset = 0;
1146 0 : for (i = 0; i < sp->timecnt; ++i)
1147 : {
1148 0 : j = sp->types[i];
1149 0 : if (!sp->ttis[j].tt_isdst)
1150 : {
1151 0 : theirstdoffset =
1152 0 : -sp->ttis[j].tt_utoff;
1153 0 : break;
1154 : }
1155 : }
1156 0 : theirdstoffset = 0;
1157 0 : for (i = 0; i < sp->timecnt; ++i)
1158 : {
1159 0 : j = sp->types[i];
1160 0 : if (sp->ttis[j].tt_isdst)
1161 : {
1162 0 : theirdstoffset =
1163 0 : -sp->ttis[j].tt_utoff;
1164 0 : break;
1165 : }
1166 : }
1167 :
1168 : /*
1169 : * Initially we're assumed to be in standard time.
1170 : */
1171 0 : isdst = false;
1172 0 : theiroffset = theirstdoffset;
1173 :
1174 : /*
1175 : * Now juggle transition times and types tracking offsets as you
1176 : * do.
1177 : */
1178 0 : for (i = 0; i < sp->timecnt; ++i)
1179 : {
1180 0 : j = sp->types[i];
1181 0 : sp->types[i] = sp->ttis[j].tt_isdst;
1182 0 : if (sp->ttis[j].tt_ttisut)
1183 : {
1184 : /* No adjustment to transition time */
1185 : }
1186 : else
1187 : {
1188 : /*
1189 : * If daylight saving time is in effect, and the
1190 : * transition time was not specified as standard time, add
1191 : * the daylight saving time offset to the transition time;
1192 : * otherwise, add the standard time offset to the
1193 : * transition time.
1194 : */
1195 : /*
1196 : * Transitions from DST to DDST will effectively disappear
1197 : * since POSIX provides for only one DST offset.
1198 : */
1199 0 : if (isdst && !sp->ttis[j].tt_ttisstd)
1200 : {
1201 0 : sp->ats[i] += dstoffset -
1202 : theirdstoffset;
1203 : }
1204 : else
1205 : {
1206 0 : sp->ats[i] += stdoffset -
1207 : theirstdoffset;
1208 : }
1209 : }
1210 0 : theiroffset = -sp->ttis[j].tt_utoff;
1211 0 : if (sp->ttis[j].tt_isdst)
1212 0 : theirdstoffset = theiroffset;
1213 : else
1214 0 : theirstdoffset = theiroffset;
1215 : }
1216 :
1217 : /*
1218 : * Finally, fill in ttis.
1219 : */
1220 0 : init_ttinfo(&sp->ttis[0], -stdoffset, false, 0);
1221 0 : init_ttinfo(&sp->ttis[1], -dstoffset, true, stdlen + 1);
1222 0 : sp->typecnt = 2;
1223 0 : sp->defaulttype = 0;
1224 : }
1225 : }
1226 : else
1227 : {
1228 7045 : dstlen = 0;
1229 7045 : sp->typecnt = 1; /* only standard time */
1230 7045 : sp->timecnt = 0;
1231 7045 : init_ttinfo(&sp->ttis[0], -stdoffset, false, 0);
1232 7045 : sp->defaulttype = 0;
1233 : }
1234 13741 : sp->charcnt = charcnt;
1235 13741 : cp = sp->chars;
1236 13741 : memcpy(cp, stdname, stdlen);
1237 13741 : cp += stdlen;
1238 13741 : *cp++ = '\0';
1239 13741 : if (dstlen != 0)
1240 : {
1241 6696 : memcpy(cp, dstname, dstlen);
1242 6696 : *(cp + dstlen) = '\0';
1243 : }
1244 13741 : return true;
1245 : }
1246 :
1247 : static void
1248 205 : gmtload(struct state *const sp)
1249 : {
1250 205 : if (tzload(gmt, NULL, sp, true) != 0)
1251 0 : tzparse(gmt, sp, true);
1252 205 : }
1253 :
1254 :
1255 : /*
1256 : * The easy way to behave "as if no library function calls" localtime
1257 : * is to not call it, so we drop its guts into "localsub", which can be
1258 : * freely called. (And no, the PANS doesn't require the above behavior,
1259 : * but it *is* desirable.)
1260 : */
1261 : static struct pg_tm *
1262 1408156 : localsub(struct state const *sp, pg_time_t const *timep,
1263 : struct pg_tm *const tmp)
1264 : {
1265 : const struct ttinfo *ttisp;
1266 : int i;
1267 : struct pg_tm *result;
1268 1408156 : const pg_time_t t = *timep;
1269 :
1270 1408156 : if (sp == NULL)
1271 0 : return gmtsub(timep, 0, tmp);
1272 1408156 : if ((sp->goback && t < sp->ats[0]) ||
1273 1408156 : (sp->goahead && t > sp->ats[sp->timecnt - 1]))
1274 : {
1275 44 : pg_time_t newt = t;
1276 : pg_time_t seconds;
1277 : pg_time_t years;
1278 :
1279 44 : if (t < sp->ats[0])
1280 0 : seconds = sp->ats[0] - t;
1281 : else
1282 44 : seconds = t - sp->ats[sp->timecnt - 1];
1283 44 : --seconds;
1284 44 : years = (seconds / SECSPERREPEAT + 1) * YEARSPERREPEAT;
1285 44 : seconds = years * AVGSECSPERYEAR;
1286 44 : if (t < sp->ats[0])
1287 0 : newt += seconds;
1288 : else
1289 44 : newt -= seconds;
1290 44 : if (newt < sp->ats[0] ||
1291 44 : newt > sp->ats[sp->timecnt - 1])
1292 0 : return NULL; /* "cannot happen" */
1293 44 : result = localsub(sp, &newt, tmp);
1294 44 : if (result)
1295 : {
1296 : int_fast64_t newy;
1297 :
1298 44 : newy = result->tm_year;
1299 44 : if (t < sp->ats[0])
1300 0 : newy -= years;
1301 : else
1302 44 : newy += years;
1303 44 : if (!(INT_MIN <= newy && newy <= INT_MAX))
1304 0 : return NULL;
1305 44 : result->tm_year = newy;
1306 : }
1307 44 : return result;
1308 : }
1309 1408112 : if (sp->timecnt == 0 || t < sp->ats[0])
1310 : {
1311 1328066 : i = sp->defaulttype;
1312 : }
1313 : else
1314 : {
1315 80046 : int lo = 1;
1316 80046 : int hi = sp->timecnt;
1317 :
1318 852726 : while (lo < hi)
1319 : {
1320 772680 : int mid = (lo + hi) >> 1;
1321 :
1322 772680 : if (t < sp->ats[mid])
1323 459683 : hi = mid;
1324 : else
1325 312997 : lo = mid + 1;
1326 : }
1327 80046 : i = (int) sp->types[lo - 1];
1328 : }
1329 1408112 : ttisp = &sp->ttis[i];
1330 :
1331 : /*
1332 : * To get (wrong) behavior that's compatible with System V Release 2.0
1333 : * you'd replace the statement below with t += ttisp->tt_utoff;
1334 : * timesub(&t, 0L, sp, tmp);
1335 : */
1336 1408112 : result = timesub(&t, ttisp->tt_utoff, sp, tmp);
1337 1408112 : if (result)
1338 : {
1339 1408112 : result->tm_isdst = ttisp->tt_isdst;
1340 1408112 : result->tm_zone = unconstify(char *, &sp->chars[ttisp->tt_desigidx]);
1341 : }
1342 1408112 : return result;
1343 : }
1344 :
1345 :
1346 : struct pg_tm *
1347 1408112 : pg_localtime(const pg_time_t *timep, const pg_tz *tz)
1348 : {
1349 1408112 : return localsub(&tz->state, timep, &tm);
1350 : }
1351 :
1352 :
1353 : /*
1354 : * gmtsub is to gmtime as localsub is to localtime.
1355 : *
1356 : * Except we have a private "struct state" for GMT, so no sp is passed in.
1357 : */
1358 :
1359 : static struct pg_tm *
1360 197753 : gmtsub(pg_time_t const *timep, int_fast32_t offset,
1361 : struct pg_tm *tmp)
1362 : {
1363 : struct pg_tm *result;
1364 :
1365 : /* GMT timezone state data is kept here */
1366 : static struct state *gmtptr = NULL;
1367 :
1368 197753 : if (gmtptr == NULL)
1369 : {
1370 : /* Allocate on first use */
1371 205 : gmtptr = (struct state *) malloc(sizeof(struct state));
1372 205 : if (gmtptr == NULL)
1373 0 : return NULL; /* errno should be set by malloc */
1374 205 : gmtload(gmtptr);
1375 : }
1376 :
1377 197753 : result = timesub(timep, offset, gmtptr, tmp);
1378 :
1379 : /*
1380 : * Could get fancy here and deliver something such as "+xx" or "-xx" if
1381 : * offset is non-zero, but this is no time for a treasure hunt.
1382 : */
1383 197753 : if (offset != 0)
1384 0 : tmp->tm_zone = wildabbr;
1385 : else
1386 197753 : tmp->tm_zone = gmtptr->chars;
1387 :
1388 197753 : return result;
1389 : }
1390 :
1391 : struct pg_tm *
1392 197753 : pg_gmtime(const pg_time_t *timep)
1393 : {
1394 197753 : return gmtsub(timep, 0, &tm);
1395 : }
1396 :
1397 : /*
1398 : * Return the number of leap years through the end of the given year
1399 : * where, to make the math easy, the answer for year zero is defined as zero.
1400 : */
1401 :
1402 : static int
1403 6413582 : leaps_thru_end_of_nonneg(int y)
1404 : {
1405 6413582 : return y / 4 - y / 100 + y / 400;
1406 : }
1407 :
1408 : static int
1409 6413582 : leaps_thru_end_of(const int y)
1410 : {
1411 : return (y < 0
1412 1552 : ? -1 - leaps_thru_end_of_nonneg(-1 - y)
1413 6415134 : : leaps_thru_end_of_nonneg(y));
1414 : }
1415 :
1416 : static struct pg_tm *
1417 1605865 : timesub(const pg_time_t *timep, int_fast32_t offset,
1418 : const struct state *sp, struct pg_tm *tmp)
1419 : {
1420 : const struct lsinfo *lp;
1421 : pg_time_t tdays;
1422 : int idays; /* unsigned would be so 2003 */
1423 : int_fast64_t rem;
1424 : int y;
1425 : const int *ip;
1426 : int_fast64_t corr;
1427 : bool hit;
1428 : int i;
1429 :
1430 1605865 : corr = 0;
1431 1605865 : hit = false;
1432 1605865 : i = (sp == NULL) ? 0 : sp->leapcnt;
1433 1605865 : while (--i >= 0)
1434 : {
1435 0 : lp = &sp->lsis[i];
1436 0 : if (*timep >= lp->ls_trans)
1437 : {
1438 0 : corr = lp->ls_corr;
1439 0 : hit = (*timep == lp->ls_trans
1440 0 : && (i == 0 ? 0 : lp[-1].ls_corr) < corr);
1441 0 : break;
1442 : }
1443 : }
1444 1605865 : y = EPOCH_YEAR;
1445 1605865 : tdays = *timep / SECSPERDAY;
1446 1605865 : rem = *timep % SECSPERDAY;
1447 3206791 : while (tdays < 0 || tdays >= year_lengths[isleap(y)])
1448 : {
1449 : int newy;
1450 : pg_time_t tdelta;
1451 : int idelta;
1452 : int leapdays;
1453 :
1454 1600926 : tdelta = tdays / DAYSPERLYEAR;
1455 1600926 : if (!((!TYPE_SIGNED(pg_time_t) || INT_MIN <= tdelta)
1456 : && tdelta <= INT_MAX))
1457 0 : goto out_of_range;
1458 1600926 : idelta = tdelta;
1459 1600926 : if (idelta == 0)
1460 26191 : idelta = (tdays < 0) ? -1 : 1;
1461 1600926 : newy = y;
1462 1600926 : if (increment_overflow(&newy, idelta))
1463 0 : goto out_of_range;
1464 1600926 : leapdays = leaps_thru_end_of(newy - 1) -
1465 1600926 : leaps_thru_end_of(y - 1);
1466 1600926 : tdays -= ((pg_time_t) newy - y) * DAYSPERNYEAR;
1467 1600926 : tdays -= leapdays;
1468 1600926 : y = newy;
1469 : }
1470 :
1471 : /*
1472 : * Given the range, we can now fearlessly cast...
1473 : */
1474 1605865 : idays = tdays;
1475 1605865 : rem += offset - corr;
1476 1629108 : while (rem < 0)
1477 : {
1478 23243 : rem += SECSPERDAY;
1479 23243 : --idays;
1480 : }
1481 1609633 : while (rem >= SECSPERDAY)
1482 : {
1483 3768 : rem -= SECSPERDAY;
1484 3768 : ++idays;
1485 : }
1486 1615016 : while (idays < 0)
1487 : {
1488 9151 : if (increment_overflow(&y, -1))
1489 0 : goto out_of_range;
1490 9151 : idays += year_lengths[isleap(y)];
1491 : }
1492 1605873 : while (idays >= year_lengths[isleap(y)])
1493 : {
1494 8 : idays -= year_lengths[isleap(y)];
1495 8 : if (increment_overflow(&y, 1))
1496 0 : goto out_of_range;
1497 : }
1498 1605865 : tmp->tm_year = y;
1499 1605865 : if (increment_overflow(&tmp->tm_year, -TM_YEAR_BASE))
1500 0 : goto out_of_range;
1501 1605865 : tmp->tm_yday = idays;
1502 :
1503 : /*
1504 : * The "extra" mods below avoid overflow problems.
1505 : */
1506 1605865 : tmp->tm_wday = EPOCH_WDAY +
1507 1605865 : ((y - EPOCH_YEAR) % DAYSPERWEEK) *
1508 1605865 : (DAYSPERNYEAR % DAYSPERWEEK) +
1509 1605865 : leaps_thru_end_of(y - 1) -
1510 1605865 : leaps_thru_end_of(EPOCH_YEAR - 1) +
1511 : idays;
1512 1605865 : tmp->tm_wday %= DAYSPERWEEK;
1513 1605865 : if (tmp->tm_wday < 0)
1514 1114 : tmp->tm_wday += DAYSPERWEEK;
1515 1605865 : tmp->tm_hour = (int) (rem / SECSPERHOUR);
1516 1605865 : rem %= SECSPERHOUR;
1517 1605865 : tmp->tm_min = (int) (rem / SECSPERMIN);
1518 :
1519 : /*
1520 : * A positive leap second requires a special representation. This uses
1521 : * "... ??:59:60" et seq.
1522 : */
1523 1605865 : tmp->tm_sec = (int) (rem % SECSPERMIN) + hit;
1524 1605865 : ip = mon_lengths[isleap(y)];
1525 7852039 : for (tmp->tm_mon = 0; idays >= ip[tmp->tm_mon]; ++(tmp->tm_mon))
1526 6246174 : idays -= ip[tmp->tm_mon];
1527 1605865 : tmp->tm_mday = (int) (idays + 1);
1528 1605865 : tmp->tm_isdst = 0;
1529 1605865 : tmp->tm_gmtoff = offset;
1530 1605865 : return tmp;
1531 :
1532 0 : out_of_range:
1533 0 : errno = EOVERFLOW;
1534 0 : return NULL;
1535 : }
1536 :
1537 : /*
1538 : * Normalize logic courtesy Paul Eggert.
1539 : */
1540 :
1541 : static bool
1542 3215950 : increment_overflow(int *ip, int j)
1543 : {
1544 3215950 : int const i = *ip;
1545 :
1546 : /*----------
1547 : * If i >= 0 there can only be overflow if i + j > INT_MAX
1548 : * or if j > INT_MAX - i; given i >= 0, INT_MAX - i cannot overflow.
1549 : * If i < 0 there can only be overflow if i + j < INT_MIN
1550 : * or if j < INT_MIN - i; given i < 0, INT_MIN - i cannot overflow.
1551 : *----------
1552 : */
1553 3215950 : if ((i >= 0) ? (j > INT_MAX - i) : (j < INT_MIN - i))
1554 0 : return true;
1555 3215950 : *ip += j;
1556 3215950 : return false;
1557 : }
1558 :
1559 : static bool
1560 21427200 : increment_overflow_time(pg_time_t *tp, int_fast32_t j)
1561 : {
1562 : /*----------
1563 : * This is like
1564 : * 'if (! (TIME_T_MIN <= *tp + j && *tp + j <= TIME_T_MAX)) ...',
1565 : * except that it does the right thing even if *tp + j would overflow.
1566 : *----------
1567 : */
1568 42854400 : if (!(j < 0
1569 1339200 : ? (TYPE_SIGNED(pg_time_t) ? TIME_T_MIN - j <= *tp : -1 - j < *tp)
1570 20088000 : : *tp <= TIME_T_MAX - j))
1571 0 : return true;
1572 21427200 : *tp += j;
1573 21427200 : return false;
1574 : }
1575 :
1576 : static int_fast64_t
1577 13372683 : leapcorr(struct state const *sp, pg_time_t t)
1578 : {
1579 : struct lsinfo const *lp;
1580 : int i;
1581 :
1582 13372683 : i = sp->leapcnt;
1583 13372683 : while (--i >= 0)
1584 : {
1585 0 : lp = &sp->lsis[i];
1586 0 : if (t >= lp->ls_trans)
1587 0 : return lp->ls_corr;
1588 : }
1589 13372683 : return 0;
1590 : }
1591 :
1592 : /*
1593 : * Find the next DST transition time in the given zone after the given time
1594 : *
1595 : * *timep and *tz are input arguments, the other parameters are output values.
1596 : *
1597 : * When the function result is 1, *boundary is set to the pg_time_t
1598 : * representation of the next DST transition time after *timep,
1599 : * *before_gmtoff and *before_isdst are set to the GMT offset and isdst
1600 : * state prevailing just before that boundary (in particular, the state
1601 : * prevailing at *timep), and *after_gmtoff and *after_isdst are set to
1602 : * the state prevailing just after that boundary.
1603 : *
1604 : * When the function result is 0, there is no known DST transition
1605 : * after *timep, but *before_gmtoff and *before_isdst indicate the GMT
1606 : * offset and isdst state prevailing at *timep. (This would occur in
1607 : * DST-less time zones, or if a zone has permanently ceased using DST.)
1608 : *
1609 : * A function result of -1 indicates failure (this case does not actually
1610 : * occur in our current implementation).
1611 : */
1612 : int
1613 108196 : pg_next_dst_boundary(const pg_time_t *timep,
1614 : long int *before_gmtoff,
1615 : int *before_isdst,
1616 : pg_time_t *boundary,
1617 : long int *after_gmtoff,
1618 : int *after_isdst,
1619 : const pg_tz *tz)
1620 : {
1621 : const struct state *sp;
1622 : const struct ttinfo *ttisp;
1623 : int i;
1624 : int j;
1625 108196 : const pg_time_t t = *timep;
1626 :
1627 108196 : sp = &tz->state;
1628 108196 : if (sp->timecnt == 0)
1629 : {
1630 : /* non-DST zone, use the defaulttype */
1631 1989 : ttisp = &sp->ttis[sp->defaulttype];
1632 1989 : *before_gmtoff = ttisp->tt_utoff;
1633 1989 : *before_isdst = ttisp->tt_isdst;
1634 1989 : return 0;
1635 : }
1636 106207 : if ((sp->goback && t < sp->ats[0]) ||
1637 106207 : (sp->goahead && t > sp->ats[sp->timecnt - 1]))
1638 : {
1639 : /* For values outside the transition table, extrapolate */
1640 32608 : pg_time_t newt = t;
1641 : pg_time_t seconds;
1642 : pg_time_t tcycles;
1643 : int64 icycles;
1644 : int result;
1645 :
1646 32608 : if (t < sp->ats[0])
1647 0 : seconds = sp->ats[0] - t;
1648 : else
1649 32608 : seconds = t - sp->ats[sp->timecnt - 1];
1650 32608 : --seconds;
1651 32608 : tcycles = seconds / YEARSPERREPEAT / AVGSECSPERYEAR;
1652 32608 : ++tcycles;
1653 32608 : icycles = tcycles;
1654 32608 : if (tcycles - icycles >= 1 || icycles - tcycles >= 1)
1655 0 : return -1;
1656 32608 : seconds = icycles;
1657 32608 : seconds *= YEARSPERREPEAT;
1658 32608 : seconds *= AVGSECSPERYEAR;
1659 32608 : if (t < sp->ats[0])
1660 0 : newt += seconds;
1661 : else
1662 32608 : newt -= seconds;
1663 32608 : if (newt < sp->ats[0] ||
1664 32608 : newt > sp->ats[sp->timecnt - 1])
1665 0 : return -1; /* "cannot happen" */
1666 :
1667 32608 : result = pg_next_dst_boundary(&newt, before_gmtoff,
1668 : before_isdst,
1669 : boundary,
1670 : after_gmtoff,
1671 : after_isdst,
1672 : tz);
1673 32608 : if (t < sp->ats[0])
1674 0 : *boundary -= seconds;
1675 : else
1676 32608 : *boundary += seconds;
1677 32608 : return result;
1678 : }
1679 :
1680 73599 : if (t >= sp->ats[sp->timecnt - 1])
1681 : {
1682 : /* No known transition > t, so use last known segment's type */
1683 720 : i = sp->types[sp->timecnt - 1];
1684 720 : ttisp = &sp->ttis[i];
1685 720 : *before_gmtoff = ttisp->tt_utoff;
1686 720 : *before_isdst = ttisp->tt_isdst;
1687 720 : return 0;
1688 : }
1689 72879 : if (t < sp->ats[0])
1690 : {
1691 : /* For "before", use the defaulttype */
1692 380 : ttisp = &sp->ttis[sp->defaulttype];
1693 380 : *before_gmtoff = ttisp->tt_utoff;
1694 380 : *before_isdst = ttisp->tt_isdst;
1695 380 : *boundary = sp->ats[0];
1696 : /* And for "after", use the first segment's type */
1697 380 : i = sp->types[0];
1698 380 : ttisp = &sp->ttis[i];
1699 380 : *after_gmtoff = ttisp->tt_utoff;
1700 380 : *after_isdst = ttisp->tt_isdst;
1701 380 : return 1;
1702 : }
1703 : /* Else search to find the boundary following t */
1704 : {
1705 72499 : int lo = 1;
1706 72499 : int hi = sp->timecnt - 1;
1707 :
1708 853554 : while (lo < hi)
1709 : {
1710 781055 : int mid = (lo + hi) >> 1;
1711 :
1712 781055 : if (t < sp->ats[mid])
1713 441663 : hi = mid;
1714 : else
1715 339392 : lo = mid + 1;
1716 : }
1717 72499 : i = lo;
1718 : }
1719 72499 : j = sp->types[i - 1];
1720 72499 : ttisp = &sp->ttis[j];
1721 72499 : *before_gmtoff = ttisp->tt_utoff;
1722 72499 : *before_isdst = ttisp->tt_isdst;
1723 72499 : *boundary = sp->ats[i];
1724 72499 : j = sp->types[i];
1725 72499 : ttisp = &sp->ttis[j];
1726 72499 : *after_gmtoff = ttisp->tt_utoff;
1727 72499 : *after_isdst = ttisp->tt_isdst;
1728 72499 : return 1;
1729 : }
1730 :
1731 : /*
1732 : * Identify a timezone abbreviation's meaning in the given zone
1733 : *
1734 : * Determine the GMT offset and DST flag associated with the abbreviation.
1735 : * This is generally used only when the abbreviation has actually changed
1736 : * meaning over time; therefore, we also take a UTC cutoff time, and return
1737 : * the meaning in use at or most recently before that time, or the meaning
1738 : * in first use after that time if the abbrev was never used before that.
1739 : *
1740 : * On success, returns true and sets *gmtoff and *isdst. If the abbreviation
1741 : * was never used at all in this zone, returns false.
1742 : *
1743 : * Note: abbrev is matched case-sensitively; it should be all-upper-case.
1744 : */
1745 : bool
1746 1134 : pg_interpret_timezone_abbrev(const char *abbrev,
1747 : const pg_time_t *timep,
1748 : long int *gmtoff,
1749 : int *isdst,
1750 : const pg_tz *tz)
1751 : {
1752 : const struct state *sp;
1753 : const char *abbrs;
1754 : const struct ttinfo *ttisp;
1755 : int abbrind;
1756 : int cutoff;
1757 : int i;
1758 1134 : const pg_time_t t = *timep;
1759 :
1760 1134 : sp = &tz->state;
1761 :
1762 : /*
1763 : * Locate the abbreviation in the zone's abbreviation list. We assume
1764 : * there are not duplicates in the list.
1765 : */
1766 1134 : abbrs = sp->chars;
1767 1134 : abbrind = 0;
1768 5872 : while (abbrind < sp->charcnt)
1769 : {
1770 5092 : if (strcmp(abbrev, abbrs + abbrind) == 0)
1771 354 : break;
1772 19598 : while (abbrs[abbrind] != '\0')
1773 14860 : abbrind++;
1774 4738 : abbrind++;
1775 : }
1776 1134 : if (abbrind >= sp->charcnt)
1777 780 : return false; /* not there! */
1778 :
1779 : /*
1780 : * Unlike pg_next_dst_boundary, we needn't sweat about extrapolation
1781 : * (goback/goahead zones). Finding the newest or oldest meaning of the
1782 : * abbreviation should get us what we want, since extrapolation would just
1783 : * be repeating the newest or oldest meanings.
1784 : *
1785 : * Use binary search to locate the first transition > cutoff time. (Note
1786 : * that sp->timecnt could be zero, in which case this loop does nothing
1787 : * and only the defaulttype entry will be checked.)
1788 : */
1789 : {
1790 354 : int lo = 0;
1791 354 : int hi = sp->timecnt;
1792 :
1793 3178 : while (lo < hi)
1794 : {
1795 2824 : int mid = (lo + hi) >> 1;
1796 :
1797 2824 : if (t < sp->ats[mid])
1798 1272 : hi = mid;
1799 : else
1800 1552 : lo = mid + 1;
1801 : }
1802 354 : cutoff = lo;
1803 : }
1804 :
1805 : /*
1806 : * Scan backwards to find the latest interval using the given abbrev
1807 : * before the cutoff time.
1808 : */
1809 13710 : for (i = cutoff - 1; i >= 0; i--)
1810 : {
1811 13682 : ttisp = &sp->ttis[sp->types[i]];
1812 13682 : if (ttisp->tt_desigidx == abbrind)
1813 : {
1814 326 : *gmtoff = ttisp->tt_utoff;
1815 326 : *isdst = ttisp->tt_isdst;
1816 326 : return true;
1817 : }
1818 : }
1819 :
1820 : /*
1821 : * Not found yet; check the defaulttype, which is notionally the era
1822 : * before any of the entries in sp->types[].
1823 : */
1824 28 : ttisp = &sp->ttis[sp->defaulttype];
1825 28 : if (ttisp->tt_desigidx == abbrind)
1826 : {
1827 28 : *gmtoff = ttisp->tt_utoff;
1828 28 : *isdst = ttisp->tt_isdst;
1829 28 : return true;
1830 : }
1831 :
1832 : /*
1833 : * Not there, so scan forwards to find the first one after the cutoff.
1834 : */
1835 0 : for (i = cutoff; i < sp->timecnt; i++)
1836 : {
1837 0 : ttisp = &sp->ttis[sp->types[i]];
1838 0 : if (ttisp->tt_desigidx == abbrind)
1839 : {
1840 0 : *gmtoff = ttisp->tt_utoff;
1841 0 : *isdst = ttisp->tt_isdst;
1842 0 : return true;
1843 : }
1844 : }
1845 :
1846 0 : return false; /* hm, not actually used in any interval? */
1847 : }
1848 :
1849 : /*
1850 : * Detect whether a timezone abbreviation is defined within the given zone.
1851 : *
1852 : * This is similar to pg_interpret_timezone_abbrev() but is not concerned
1853 : * with a specific point in time. We want to know if the abbreviation is
1854 : * known at all, and if so whether it has one meaning or several.
1855 : *
1856 : * Returns true if the abbreviation is known, false if not.
1857 : * If the abbreviation is known and has a single meaning (only one value
1858 : * of gmtoff/isdst), sets *isfixed = true and sets *gmtoff and *isdst.
1859 : * If there are multiple meanings, sets *isfixed = false.
1860 : *
1861 : * Note: abbrev is matched case-sensitively; it should be all-upper-case.
1862 : */
1863 : bool
1864 4955 : pg_timezone_abbrev_is_known(const char *abbrev,
1865 : bool *isfixed,
1866 : long int *gmtoff,
1867 : int *isdst,
1868 : const pg_tz *tz)
1869 : {
1870 4955 : bool result = false;
1871 4955 : const struct state *sp = &tz->state;
1872 : const char *abbrs;
1873 : int abbrind;
1874 :
1875 : /*
1876 : * Locate the abbreviation in the zone's abbreviation list. We assume
1877 : * there are not duplicates in the list.
1878 : */
1879 4955 : abbrs = sp->chars;
1880 4955 : abbrind = 0;
1881 28337 : while (abbrind < sp->charcnt)
1882 : {
1883 23535 : if (strcmp(abbrev, abbrs + abbrind) == 0)
1884 153 : break;
1885 93568 : while (abbrs[abbrind] != '\0')
1886 70186 : abbrind++;
1887 23382 : abbrind++;
1888 : }
1889 4955 : if (abbrind >= sp->charcnt)
1890 4802 : return false; /* definitely not there */
1891 :
1892 : /*
1893 : * Scan the ttinfo array to find uses of the abbreviation.
1894 : */
1895 1211 : for (int i = 0; i < sp->typecnt; i++)
1896 : {
1897 1058 : const struct ttinfo *ttisp = &sp->ttis[i];
1898 :
1899 1058 : if (ttisp->tt_desigidx == abbrind)
1900 : {
1901 290 : if (!result)
1902 : {
1903 : /* First usage */
1904 153 : *isfixed = true; /* for the moment */
1905 153 : *gmtoff = ttisp->tt_utoff;
1906 153 : *isdst = ttisp->tt_isdst;
1907 153 : result = true;
1908 : }
1909 : else
1910 : {
1911 : /* Second or later usage, does it match? */
1912 137 : if (*gmtoff != ttisp->tt_utoff ||
1913 137 : *isdst != ttisp->tt_isdst)
1914 : {
1915 0 : *isfixed = false;
1916 0 : break; /* no point in looking further */
1917 : }
1918 : }
1919 : }
1920 : }
1921 :
1922 153 : return result;
1923 : }
1924 :
1925 : /*
1926 : * Iteratively fetch all the abbreviations used in the given time zone.
1927 : *
1928 : * *indx is a state counter that the caller must initialize to zero
1929 : * before the first call, and not touch between calls.
1930 : *
1931 : * Returns the next known abbreviation, or NULL if there are no more.
1932 : *
1933 : * Note: the caller typically applies pg_interpret_timezone_abbrev()
1934 : * to each result. While that nominally results in O(N^2) time spent
1935 : * searching the sp->chars[] array, we don't expect any zone to have
1936 : * enough abbreviations to make that meaningful.
1937 : */
1938 : const char *
1939 168 : pg_get_next_timezone_abbrev(int *indx,
1940 : const pg_tz *tz)
1941 : {
1942 : const char *result;
1943 168 : const struct state *sp = &tz->state;
1944 : const char *abbrs;
1945 : int abbrind;
1946 :
1947 : /* If we're still in range, the result is the current abbrev. */
1948 168 : abbrs = sp->chars;
1949 168 : abbrind = *indx;
1950 168 : if (abbrind < 0 || abbrind >= sp->charcnt)
1951 28 : return NULL;
1952 140 : result = abbrs + abbrind;
1953 :
1954 : /* Advance *indx past this abbrev and its trailing null. */
1955 560 : while (abbrs[abbrind] != '\0')
1956 420 : abbrind++;
1957 140 : abbrind++;
1958 140 : *indx = abbrind;
1959 :
1960 140 : return result;
1961 : }
1962 :
1963 : /*
1964 : * If the given timezone uses only one GMT offset, store that offset
1965 : * into *gmtoff and return true, else return false.
1966 : */
1967 : bool
1968 621 : pg_get_timezone_offset(const pg_tz *tz, long int *gmtoff)
1969 : {
1970 : /*
1971 : * The zone could have more than one ttinfo, if it's historically used
1972 : * more than one abbreviation. We return true as long as they all have
1973 : * the same gmtoff.
1974 : */
1975 : const struct state *sp;
1976 : int i;
1977 :
1978 621 : sp = &tz->state;
1979 639 : for (i = 1; i < sp->typecnt; i++)
1980 : {
1981 74 : if (sp->ttis[i].tt_utoff != sp->ttis[0].tt_utoff)
1982 56 : return false;
1983 : }
1984 565 : *gmtoff = sp->ttis[0].tt_utoff;
1985 565 : return true;
1986 : }
1987 :
1988 : /*
1989 : * Return the name of the current timezone
1990 : */
1991 : const char *
1992 39987 : pg_get_timezone_name(pg_tz *tz)
1993 : {
1994 39987 : if (tz)
1995 39987 : return tz->TZname;
1996 0 : return NULL;
1997 : }
1998 :
1999 : /*
2000 : * Check whether timezone is acceptable.
2001 : *
2002 : * What we are doing here is checking for leap-second-aware timekeeping.
2003 : * We need to reject such TZ settings because they'll wreak havoc with our
2004 : * date/time arithmetic.
2005 : */
2006 : bool
2007 23511 : pg_tz_acceptable(pg_tz *tz)
2008 : {
2009 : struct pg_tm *tt;
2010 : pg_time_t time2000;
2011 :
2012 : /*
2013 : * To detect leap-second timekeeping, run pg_localtime for what should be
2014 : * GMT midnight, 2000-01-01. Insist that the tm_sec value be zero; any
2015 : * other result has to be due to leap seconds.
2016 : */
2017 23511 : time2000 = (POSTGRES_EPOCH_JDATE - UNIX_EPOCH_JDATE) * SECS_PER_DAY;
2018 23511 : tt = pg_localtime(&time2000, tz);
2019 23511 : if (!tt || tt->tm_sec != 0)
2020 0 : return false;
2021 :
2022 23511 : return true;
2023 : }
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