1 /* 2 ** This file is in the public domain, so clarified as of 3 ** 1996-06-05 by Arthur David Olson. 4 ** 5 ** $FreeBSD: head/contrib/tzcode/stdtime/localtime.c 226828 2011-10-27 08:44:07Z trociny $ 6 */ 7 8 /* 9 ** Leap second handling from Bradley White. 10 ** POSIX-style TZ environment variable handling from Guy Harris. 11 */ 12 13 /*LINTLIBRARY*/ 14 15 #include "namespace.h" 16 #include <sys/types.h> 17 #include <sys/stat.h> 18 19 #include <errno.h> 20 #include <fcntl.h> 21 #include <time.h> 22 #include <pthread.h> 23 #include "private.h" 24 #include "libc_private.h" 25 #include <un-namespace.h> 26 27 #include "tzfile.h" 28 29 #ifndef TZ_ABBR_MAX_LEN 30 #define TZ_ABBR_MAX_LEN 16 31 #endif /* !defined TZ_ABBR_MAX_LEN */ 32 33 #ifndef TZ_ABBR_CHAR_SET 34 #define TZ_ABBR_CHAR_SET \ 35 "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789 :+-._" 36 #endif /* !defined TZ_ABBR_CHAR_SET */ 37 38 #ifndef TZ_ABBR_ERR_CHAR 39 #define TZ_ABBR_ERR_CHAR '_' 40 #endif /* !defined TZ_ABBR_ERR_CHAR */ 41 42 #define _MUTEX_LOCK(x) if (__isthreaded) _pthread_mutex_lock(x) 43 #define _MUTEX_UNLOCK(x) if (__isthreaded) _pthread_mutex_unlock(x) 44 45 #define _RWLOCK_RDLOCK(x) \ 46 do { \ 47 if (__isthreaded) _pthread_rwlock_rdlock(x); \ 48 } while (0) 49 50 #define _RWLOCK_WRLOCK(x) \ 51 do { \ 52 if (__isthreaded) _pthread_rwlock_wrlock(x); \ 53 } while (0) 54 55 #define _RWLOCK_UNLOCK(x) \ 56 do { \ 57 if (__isthreaded) _pthread_rwlock_unlock(x); \ 58 } while (0) 59 60 /* 61 ** Someone might make incorrect use of a time zone abbreviation: 62 ** 1. They might reference tzname[0] before calling tzset (explicitly 63 ** or implicitly). 64 ** 2. They might reference tzname[1] before calling tzset (explicitly 65 ** or implicitly). 66 ** 3. They might reference tzname[1] after setting to a time zone 67 ** in which Daylight Saving Time is never observed. 68 ** 4. They might reference tzname[0] after setting to a time zone 69 ** in which Standard Time is never observed. 70 ** 5. They might reference tm.TM_ZONE after calling offtime. 71 ** What's best to do in the above cases is open to debate; 72 ** for now, we just set things up so that in any of the five cases 73 ** WILDABBR is used. Another possibility: initialize tzname[0] to the 74 ** string "tzname[0] used before set", and similarly for the other cases. 75 ** And another: initialize tzname[0] to "ERA", with an explanation in the 76 ** manual page of what this "time zone abbreviation" means (doing this so 77 ** that tzname[0] has the "normal" length of three characters). 78 */ 79 #define WILDABBR " " 80 81 static char wildabbr[] = WILDABBR; 82 83 static const char gmt[] = "UTC"; 84 85 /* 86 ** The DST rules to use if TZ has no rules and we can't load TZDEFRULES. 87 ** We default to US rules as of 1999-08-17. 88 ** POSIX 1003.1 section 8.1.1 says that the default DST rules are 89 ** implementation dependent; for historical reasons, US rules are a 90 ** common default. 91 */ 92 #ifndef TZDEFRULESTRING 93 #define TZDEFRULESTRING ",M4.1.0,M10.5.0" 94 #endif /* !defined TZDEFDST */ 95 96 struct ttinfo { /* time type information */ 97 int_fast32_t tt_gmtoff; /* UT offset in seconds */ 98 int tt_isdst; /* used to set tm_isdst */ 99 int tt_abbrind; /* abbreviation list index */ 100 int tt_ttisstd; /* TRUE if transition is std time */ 101 int tt_ttisgmt; /* TRUE if transition is UT */ 102 }; 103 104 struct lsinfo { /* leap second information */ 105 time_t ls_trans; /* transition time */ 106 int_fast64_t ls_corr; /* correction to apply */ 107 }; 108 109 #define BIGGEST(a, b) (((a) > (b)) ? (a) : (b)) 110 111 #ifdef TZNAME_MAX 112 #define MY_TZNAME_MAX TZNAME_MAX 113 #endif /* defined TZNAME_MAX */ 114 #ifndef TZNAME_MAX 115 #define MY_TZNAME_MAX 255 116 #endif /* !defined TZNAME_MAX */ 117 118 struct state { 119 int leapcnt; 120 int timecnt; 121 int typecnt; 122 int charcnt; 123 int goback; 124 int goahead; 125 time_t ats[TZ_MAX_TIMES]; 126 unsigned char types[TZ_MAX_TIMES]; 127 struct ttinfo ttis[TZ_MAX_TYPES]; 128 char chars[BIGGEST(BIGGEST(TZ_MAX_CHARS + 1, sizeof gmt), 129 (2 * (MY_TZNAME_MAX + 1)))]; 130 struct lsinfo lsis[TZ_MAX_LEAPS]; 131 int defaulttype; /* for early times or if no transitions */ 132 }; 133 134 struct rule { 135 int r_type; /* type of rule--see below */ 136 int r_day; /* day number of rule */ 137 int r_week; /* week number of rule */ 138 int r_mon; /* month number of rule */ 139 int_fast32_t r_time; /* transition time of rule */ 140 }; 141 142 #define JULIAN_DAY 0 /* Jn - Julian day */ 143 #define DAY_OF_YEAR 1 /* n - day of year */ 144 #define MONTH_NTH_DAY_OF_WEEK 2 /* Mm.n.d - month, week, day of week */ 145 146 /* 147 ** Prototypes for static functions. 148 */ 149 150 static int_fast32_t detzcode(const char * codep); 151 static int_fast64_t detzcode64(const char * codep); 152 static int differ_by_repeat(time_t t1, time_t t0); 153 static const char * getzname(const char * strp) __pure; 154 static const char * getqzname(const char * strp, const int delim) __pure; 155 static const char * getnum(const char * strp, int * nump, int min, 156 int max); 157 static const char * getsecs(const char * strp, int_fast32_t * secsp); 158 static const char * getoffset(const char * strp, int_fast32_t * offsetp); 159 static const char * getrule(const char * strp, struct rule * rulep); 160 static void gmtload(struct state * sp); 161 static struct tm * gmtsub(const time_t * timep, int_fast32_t offset, 162 struct tm * tmp); 163 static struct tm * localsub(const time_t * timep, int_fast32_t offset, 164 struct tm * tmp); 165 static int increment_overflow(int * number, int delta); 166 static int leaps_thru_end_of(int y) __pure; 167 static int increment_overflow32(int_fast32_t * number, int delta); 168 static int increment_overflow_time(time_t *t, int_fast32_t delta); 169 static int normalize_overflow32(int_fast32_t * tensptr, 170 int * unitsptr, int base); 171 static int normalize_overflow(int * tensptr, int * unitsptr, 172 int base); 173 static void settzname(void); 174 static time_t time1(struct tm * tmp, 175 struct tm * (*funcp)(const time_t *, 176 int_fast32_t, struct tm *), 177 int_fast32_t offset); 178 static time_t time2(struct tm *tmp, 179 struct tm * (*funcp)(const time_t *, 180 int_fast32_t, struct tm*), 181 int_fast32_t offset, int * okayp); 182 static time_t time2sub(struct tm *tmp, 183 struct tm * (*funcp)(const time_t *, 184 int_fast32_t, struct tm*), 185 int_fast32_t offset, int * okayp, int do_norm_secs); 186 static struct tm * timesub(const time_t * timep, int_fast32_t offset, 187 const struct state * sp, struct tm * tmp); 188 static int tmcomp(const struct tm * atmp, 189 const struct tm * btmp); 190 static int_fast32_t transtime(int year, const struct rule * rulep, 191 int_fast32_t offset) __pure; 192 static int typesequiv(const struct state * sp, int a, int b); 193 static int tzload(const char * name, struct state * sp, 194 int doextend); 195 static int tzparse(const char * name, struct state * sp, 196 int lastditch); 197 198 static struct state lclmem; 199 static struct state gmtmem; 200 #define lclptr (&lclmem) 201 #define gmtptr (&gmtmem) 202 203 #ifndef TZ_STRLEN_MAX 204 #define TZ_STRLEN_MAX 255 205 #endif /* !defined TZ_STRLEN_MAX */ 206 207 static char lcl_TZname[TZ_STRLEN_MAX + 1]; 208 static int lcl_is_set; 209 static pthread_once_t gmt_once = PTHREAD_ONCE_INIT; 210 static pthread_rwlock_t lcl_rwlock = PTHREAD_RWLOCK_INITIALIZER; 211 static pthread_once_t gmtime_once = PTHREAD_ONCE_INIT; 212 static pthread_key_t gmtime_key; 213 static int gmtime_key_error; 214 static pthread_once_t localtime_once = PTHREAD_ONCE_INIT; 215 static pthread_key_t localtime_key; 216 static int localtime_key_error; 217 218 char * tzname[2] = { 219 wildabbr, 220 wildabbr 221 }; 222 223 /* 224 ** Section 4.12.3 of X3.159-1989 requires that 225 ** Except for the strftime function, these functions [asctime, 226 ** ctime, gmtime, localtime] return values in one of two static 227 ** objects: a broken-down time structure and an array of char. 228 ** Thanks to Paul Eggert for noting this. 229 */ 230 231 static struct tm tm; 232 233 long timezone = 0; 234 int daylight = 0; 235 236 static int_fast32_t 237 detzcode(const char * const codep) 238 { 239 int_fast32_t result; 240 int i; 241 242 result = (codep[0] & 0x80) ? -1 : 0; 243 for (i = 0; i < 4; ++i) 244 result = (result << 8) | (codep[i] & 0xff); 245 return result; 246 } 247 248 static int_fast64_t 249 detzcode64(const char * const codep) 250 { 251 int_fast64_t result; 252 int i; 253 254 result = (codep[0] & 0x80) ? -1 : 0; 255 for (i = 0; i < 8; ++i) 256 result = (result << 8) | (codep[i] & 0xff); 257 return result; 258 } 259 260 static void 261 settzname(void) 262 { 263 struct state * const sp = lclptr; 264 int i; 265 266 tzname[0] = wildabbr; 267 tzname[1] = wildabbr; 268 daylight = 0; 269 timezone = 0; 270 271 /* 272 ** And to get the latest zone names into tzname. . . 273 */ 274 for (i = 0; i < sp->typecnt; ++i) { 275 const struct ttinfo * const ttisp = &sp->ttis[i]; 276 277 tzname[ttisp->tt_isdst] = &sp->chars[ttisp->tt_abbrind]; 278 } 279 for (i = 0; i < sp->timecnt; ++i) { 280 const struct ttinfo * const ttisp = &sp->ttis[sp->types[i]]; 281 282 tzname[ttisp->tt_isdst] = 283 &sp->chars[ttisp->tt_abbrind]; 284 if (ttisp->tt_isdst) 285 daylight = 1; 286 if (!ttisp->tt_isdst) 287 timezone = -(ttisp->tt_gmtoff); 288 } 289 /* 290 ** Finally, scrub the abbreviations. 291 ** First, replace bogus characters. 292 */ 293 for (i = 0; i < sp->charcnt; ++i) 294 if (strchr(TZ_ABBR_CHAR_SET, sp->chars[i]) == NULL) 295 sp->chars[i] = TZ_ABBR_ERR_CHAR; 296 /* 297 ** Second, truncate long abbreviations. 298 */ 299 for (i = 0; i < sp->typecnt; ++i) { 300 const struct ttinfo * const ttisp = &sp->ttis[i]; 301 char * cp = &sp->chars[ttisp->tt_abbrind]; 302 303 if (strlen(cp) > TZ_ABBR_MAX_LEN && 304 strcmp(cp, GRANDPARENTED) != 0) 305 *(cp + TZ_ABBR_MAX_LEN) = '\0'; 306 } 307 } 308 309 static int 310 differ_by_repeat(const time_t t1, const time_t t0) 311 { 312 if (TYPE_BIT(time_t) - TYPE_SIGNED(time_t) < SECSPERREPEAT_BITS) 313 return 0; 314 return t1 - t0 == SECSPERREPEAT; 315 } 316 317 static int 318 tzload(const char *name, struct state * const sp, const int doextend) 319 { 320 const char * p; 321 int i; 322 int fid; 323 int stored; 324 int nread; 325 int res; 326 typedef union { 327 struct tzhead tzhead; 328 char buf[2 * sizeof(struct tzhead) + 329 2 * sizeof *sp + 330 4 * TZ_MAX_TIMES]; 331 } u_t; 332 u_t *u; 333 334 u = NULL; 335 res = -1; 336 sp->goback = sp->goahead = FALSE; 337 338 /* XXX The following is from OpenBSD, and I'm not sure it is correct */ 339 if (name != NULL && issetugid() != 0) 340 if ((name[0] == ':' && name[1] == '/') || 341 name[0] == '/' || strchr(name, '.')) 342 name = NULL; 343 if (name == NULL && (name = TZDEFAULT) == NULL) 344 return -1; 345 { 346 int doaccess; 347 struct stat stab; 348 /* 349 ** Section 4.9.1 of the C standard says that 350 ** "FILENAME_MAX expands to an integral constant expression 351 ** that is the size needed for an array of char large enough 352 ** to hold the longest file name string that the implementation 353 ** guarantees can be opened." 354 */ 355 char *fullname; 356 357 fullname = malloc(FILENAME_MAX + 1); 358 if (fullname == NULL) 359 goto out; 360 361 if (name[0] == ':') 362 ++name; 363 doaccess = name[0] == '/'; 364 if (!doaccess) { 365 if ((p = TZDIR) == NULL) { 366 free(fullname); 367 return -1; 368 } 369 if (strlen(p) + 1 + strlen(name) >= FILENAME_MAX) { 370 free(fullname); 371 return -1; 372 } 373 strcpy(fullname, p); 374 strcat(fullname, "/"); 375 strcat(fullname, name); 376 /* 377 ** Set doaccess if '.' (as in "../") shows up in name. 378 */ 379 if (strchr(name, '.') != NULL) 380 doaccess = TRUE; 381 name = fullname; 382 } 383 if (doaccess && access(name, R_OK) != 0) { 384 free(fullname); 385 return -1; 386 } 387 if ((fid = _open(name, O_RDONLY)) == -1) { 388 free(fullname); 389 return -1; 390 } 391 if ((_fstat(fid, &stab) < 0) || !S_ISREG(stab.st_mode)) { 392 free(fullname); 393 _close(fid); 394 return -1; 395 } 396 free(fullname); 397 } 398 u = malloc(sizeof(*u)); 399 if (u == NULL) 400 goto out; 401 nread = _read(fid, u->buf, sizeof u->buf); 402 if (_close(fid) < 0 || nread <= 0) 403 goto out; 404 for (stored = 4; stored <= 8; stored *= 2) { 405 int ttisstdcnt; 406 int ttisgmtcnt; 407 int timecnt; 408 409 ttisstdcnt = (int) detzcode(u->tzhead.tzh_ttisstdcnt); 410 ttisgmtcnt = (int) detzcode(u->tzhead.tzh_ttisgmtcnt); 411 sp->leapcnt = (int) detzcode(u->tzhead.tzh_leapcnt); 412 sp->timecnt = (int) detzcode(u->tzhead.tzh_timecnt); 413 sp->typecnt = (int) detzcode(u->tzhead.tzh_typecnt); 414 sp->charcnt = (int) detzcode(u->tzhead.tzh_charcnt); 415 p = u->tzhead.tzh_charcnt + sizeof u->tzhead.tzh_charcnt; 416 if (sp->leapcnt < 0 || sp->leapcnt > TZ_MAX_LEAPS || 417 sp->typecnt <= 0 || sp->typecnt > TZ_MAX_TYPES || 418 sp->timecnt < 0 || sp->timecnt > TZ_MAX_TIMES || 419 sp->charcnt < 0 || sp->charcnt > TZ_MAX_CHARS || 420 (ttisstdcnt != sp->typecnt && ttisstdcnt != 0) || 421 (ttisgmtcnt != sp->typecnt && ttisgmtcnt != 0)) 422 goto out; 423 if (nread - (p - u->buf) < 424 sp->timecnt * stored + /* ats */ 425 sp->timecnt + /* types */ 426 sp->typecnt * 6 + /* ttinfos */ 427 sp->charcnt + /* chars */ 428 sp->leapcnt * (stored + 4) + /* lsinfos */ 429 ttisstdcnt + /* ttisstds */ 430 ttisgmtcnt) /* ttisgmts */ 431 goto out; 432 timecnt = 0; 433 for (i = 0; i < sp->timecnt; ++i) { 434 int_fast64_t at 435 = stored == 4 ? detzcode(p) : detzcode64(p); 436 sp->types[i] = ((TYPE_SIGNED(time_t) 437 ? time_t_min <= at 438 : 0 <= at) 439 && at <= time_t_max); 440 if (sp->types[i]) { 441 if (i && !timecnt && at != time_t_min) { 442 /* 443 ** Keep the earlier record, but tweak 444 ** it so that it starts with the 445 ** minimum time_t value. 446 */ 447 sp->types[i - 1] = 1; 448 sp->ats[timecnt++] = time_t_min; 449 } 450 sp->ats[timecnt++] = at; 451 } 452 p += stored; 453 } 454 timecnt = 0; 455 for (i = 0; i < sp->timecnt; ++i) { 456 unsigned char typ = *p++; 457 if (sp->typecnt <= typ) 458 goto out; 459 if (sp->types[i]) 460 sp->types[timecnt++] = typ; 461 } 462 sp->timecnt = timecnt; 463 for (i = 0; i < sp->typecnt; ++i) { 464 struct ttinfo * ttisp; 465 466 ttisp = &sp->ttis[i]; 467 ttisp->tt_gmtoff = detzcode(p); 468 p += 4; 469 ttisp->tt_isdst = (unsigned char) *p++; 470 if (ttisp->tt_isdst != 0 && ttisp->tt_isdst != 1) 471 goto out; 472 ttisp->tt_abbrind = (unsigned char) *p++; 473 if (ttisp->tt_abbrind < 0 || 474 ttisp->tt_abbrind > sp->charcnt) 475 goto out; 476 } 477 for (i = 0; i < sp->charcnt; ++i) 478 sp->chars[i] = *p++; 479 sp->chars[i] = '\0'; /* ensure '\0' at end */ 480 for (i = 0; i < sp->leapcnt; ++i) { 481 struct lsinfo * lsisp; 482 483 lsisp = &sp->lsis[i]; 484 lsisp->ls_trans = (stored == 4) ? 485 detzcode(p) : detzcode64(p); 486 p += stored; 487 lsisp->ls_corr = detzcode(p); 488 p += 4; 489 } 490 for (i = 0; i < sp->typecnt; ++i) { 491 struct ttinfo * ttisp; 492 493 ttisp = &sp->ttis[i]; 494 if (ttisstdcnt == 0) 495 ttisp->tt_ttisstd = FALSE; 496 else { 497 ttisp->tt_ttisstd = *p++; 498 if (ttisp->tt_ttisstd != TRUE && 499 ttisp->tt_ttisstd != FALSE) 500 goto out; 501 } 502 } 503 for (i = 0; i < sp->typecnt; ++i) { 504 struct ttinfo * ttisp; 505 506 ttisp = &sp->ttis[i]; 507 if (ttisgmtcnt == 0) 508 ttisp->tt_ttisgmt = FALSE; 509 else { 510 ttisp->tt_ttisgmt = *p++; 511 if (ttisp->tt_ttisgmt != TRUE && 512 ttisp->tt_ttisgmt != FALSE) 513 goto out; 514 } 515 } 516 /* 517 ** If this is an old file, we're done. 518 */ 519 if (u->tzhead.tzh_version[0] == '\0') 520 break; 521 nread -= p - u->buf; 522 for (i = 0; i < nread; ++i) 523 u->buf[i] = p[i]; 524 /* 525 ** If this is a signed narrow time_t system, we're done. 526 */ 527 if (TYPE_SIGNED(time_t) && stored >= (int) sizeof(time_t)) 528 break; 529 } 530 if (doextend && nread > 2 && 531 u->buf[0] == '\n' && u->buf[nread - 1] == '\n' && 532 sp->typecnt + 2 <= TZ_MAX_TYPES) { 533 struct state *ts; 534 int result; 535 536 ts = malloc(sizeof(*ts)); 537 if (ts == NULL) 538 goto out; 539 u->buf[nread - 1] = '\0'; 540 result = tzparse(&u->buf[1], ts, FALSE); 541 if (result == 0 && ts->typecnt == 2 && 542 sp->charcnt + ts->charcnt <= TZ_MAX_CHARS) { 543 for (i = 0; i < 2; ++i) 544 ts->ttis[i].tt_abbrind += 545 sp->charcnt; 546 for (i = 0; i < ts->charcnt; ++i) 547 sp->chars[sp->charcnt++] = 548 ts->chars[i]; 549 i = 0; 550 while (i < ts->timecnt && 551 ts->ats[i] <= 552 sp->ats[sp->timecnt - 1]) 553 ++i; 554 while (i < ts->timecnt && 555 sp->timecnt < TZ_MAX_TIMES) { 556 sp->ats[sp->timecnt] = 557 ts->ats[i]; 558 sp->types[sp->timecnt] = 559 sp->typecnt + 560 ts->types[i]; 561 ++sp->timecnt; 562 ++i; 563 } 564 sp->ttis[sp->typecnt++] = ts->ttis[0]; 565 sp->ttis[sp->typecnt++] = ts->ttis[1]; 566 } 567 free(ts); 568 } 569 if (sp->timecnt > 1) { 570 for (i = 1; i < sp->timecnt; ++i) 571 if (typesequiv(sp, sp->types[i], sp->types[0]) && 572 differ_by_repeat(sp->ats[i], sp->ats[0])) { 573 sp->goback = TRUE; 574 break; 575 } 576 for (i = sp->timecnt - 2; i >= 0; --i) 577 if (typesequiv(sp, sp->types[sp->timecnt - 1], 578 sp->types[i]) && 579 differ_by_repeat(sp->ats[sp->timecnt - 1], 580 sp->ats[i])) { 581 sp->goahead = TRUE; 582 break; 583 } 584 } 585 /* 586 ** If type 0 is is unused in transitions, 587 ** it's the type to use for early times. 588 */ 589 for (i = 0; i < sp->typecnt; ++i) 590 if (sp->types[i] == 0) 591 break; 592 i = (i >= sp->typecnt) ? 0 : -1; 593 /* 594 ** Absent the above, 595 ** if there are transition times 596 ** and the first transition is to a daylight time 597 ** find the standard type less than and closest to 598 ** the type of the first transition. 599 */ 600 if (i < 0 && sp->timecnt > 0 && sp->ttis[sp->types[0]].tt_isdst) { 601 i = sp->types[0]; 602 while (--i >= 0) 603 if (!sp->ttis[i].tt_isdst) 604 break; 605 } 606 /* 607 ** If no result yet, find the first standard type. 608 ** If there is none, punt to type zero. 609 */ 610 if (i < 0) { 611 i = 0; 612 while (sp->ttis[i].tt_isdst) 613 if (++i >= sp->typecnt) { 614 i = 0; 615 break; 616 } 617 } 618 sp->defaulttype = i; 619 res = 0; 620 out: 621 free(u); 622 return (res); 623 } 624 625 static int 626 typesequiv(const struct state * const sp, const int a, const int b) 627 { 628 int result; 629 630 if (sp == NULL || 631 a < 0 || a >= sp->typecnt || 632 b < 0 || b >= sp->typecnt) 633 result = FALSE; 634 else { 635 const struct ttinfo * ap = &sp->ttis[a]; 636 const struct ttinfo * bp = &sp->ttis[b]; 637 result = ap->tt_gmtoff == bp->tt_gmtoff && 638 ap->tt_isdst == bp->tt_isdst && 639 ap->tt_ttisstd == bp->tt_ttisstd && 640 ap->tt_ttisgmt == bp->tt_ttisgmt && 641 strcmp(&sp->chars[ap->tt_abbrind], 642 &sp->chars[bp->tt_abbrind]) == 0; 643 } 644 return result; 645 } 646 647 static const int mon_lengths[2][MONSPERYEAR] = { 648 { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }, 649 { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 } 650 }; 651 652 static const int year_lengths[2] = { 653 DAYSPERNYEAR, DAYSPERLYEAR 654 }; 655 656 /* 657 ** Given a pointer into a time zone string, scan until a character that is not 658 ** a valid character in a zone name is found. Return a pointer to that 659 ** character. 660 */ 661 662 static const char * 663 getzname(const char *strp) 664 { 665 char c; 666 667 while ((c = *strp) != '\0' && !is_digit(c) && c != ',' && c != '-' && 668 c != '+') 669 ++strp; 670 return strp; 671 } 672 673 /* 674 ** Given a pointer into an extended time zone string, scan until the ending 675 ** delimiter of the zone name is located. Return a pointer to the delimiter. 676 ** 677 ** As with getzname above, the legal character set is actually quite 678 ** restricted, with other characters producing undefined results. 679 ** We don't do any checking here; checking is done later in common-case code. 680 */ 681 682 static const char * 683 getqzname(const char *strp, const int delim) 684 { 685 int c; 686 687 while ((c = *strp) != '\0' && c != delim) 688 ++strp; 689 return strp; 690 } 691 692 /* 693 ** Given a pointer into a time zone string, extract a number from that string. 694 ** Check that the number is within a specified range; if it is not, return 695 ** NULL. 696 ** Otherwise, return a pointer to the first character not part of the number. 697 */ 698 699 static const char * 700 getnum(const char *strp, int * const nump, const int min, const int max) 701 { 702 char c; 703 int num; 704 705 if (strp == NULL || !is_digit(c = *strp)) 706 return NULL; 707 num = 0; 708 do { 709 num = num * 10 + (c - '0'); 710 if (num > max) 711 return NULL; /* illegal value */ 712 c = *++strp; 713 } while (is_digit(c)); 714 if (num < min) 715 return NULL; /* illegal value */ 716 *nump = num; 717 return strp; 718 } 719 720 /* 721 ** Given a pointer into a time zone string, extract a number of seconds, 722 ** in hh[:mm[:ss]] form, from the string. 723 ** If any error occurs, return NULL. 724 ** Otherwise, return a pointer to the first character not part of the number 725 ** of seconds. 726 */ 727 728 static const char * 729 getsecs(const char *strp, int_fast32_t * const secsp) 730 { 731 int num; 732 733 /* 734 ** `HOURSPERDAY * DAYSPERWEEK - 1' allows quasi-Posix rules like 735 ** "M10.4.6/26", which does not conform to Posix, 736 ** but which specifies the equivalent of 737 ** ``02:00 on the first Sunday on or after 23 Oct''. 738 */ 739 strp = getnum(strp, &num, 0, HOURSPERDAY * DAYSPERWEEK - 1); 740 if (strp == NULL) 741 return NULL; 742 *secsp = num * (int_fast32_t) SECSPERHOUR; 743 if (*strp == ':') { 744 ++strp; 745 strp = getnum(strp, &num, 0, MINSPERHOUR - 1); 746 if (strp == NULL) 747 return NULL; 748 *secsp += num * SECSPERMIN; 749 if (*strp == ':') { 750 ++strp; 751 /* `SECSPERMIN' allows for leap seconds. */ 752 strp = getnum(strp, &num, 0, SECSPERMIN); 753 if (strp == NULL) 754 return NULL; 755 *secsp += num; 756 } 757 } 758 return strp; 759 } 760 761 /* 762 ** Given a pointer into a time zone string, extract an offset, in 763 ** [+-]hh[:mm[:ss]] form, from the string. 764 ** If any error occurs, return NULL. 765 ** Otherwise, return a pointer to the first character not part of the time. 766 */ 767 768 static const char * 769 getoffset(const char *strp, int_fast32_t * const offsetp) 770 { 771 int neg = 0; 772 773 if (*strp == '-') { 774 neg = 1; 775 ++strp; 776 } else if (*strp == '+') 777 ++strp; 778 strp = getsecs(strp, offsetp); 779 if (strp == NULL) 780 return NULL; /* illegal time */ 781 if (neg) 782 *offsetp = -*offsetp; 783 return strp; 784 } 785 786 /* 787 ** Given a pointer into a time zone string, extract a rule in the form 788 ** date[/time]. See POSIX section 8 for the format of "date" and "time". 789 ** If a valid rule is not found, return NULL. 790 ** Otherwise, return a pointer to the first character not part of the rule. 791 */ 792 793 static const char * 794 getrule(const char *strp, struct rule * const rulep) 795 { 796 if (*strp == 'J') { 797 /* 798 ** Julian day. 799 */ 800 rulep->r_type = JULIAN_DAY; 801 ++strp; 802 strp = getnum(strp, &rulep->r_day, 1, DAYSPERNYEAR); 803 } else if (*strp == 'M') { 804 /* 805 ** Month, week, day. 806 */ 807 rulep->r_type = MONTH_NTH_DAY_OF_WEEK; 808 ++strp; 809 strp = getnum(strp, &rulep->r_mon, 1, MONSPERYEAR); 810 if (strp == NULL) 811 return NULL; 812 if (*strp++ != '.') 813 return NULL; 814 strp = getnum(strp, &rulep->r_week, 1, 5); 815 if (strp == NULL) 816 return NULL; 817 if (*strp++ != '.') 818 return NULL; 819 strp = getnum(strp, &rulep->r_day, 0, DAYSPERWEEK - 1); 820 } else if (is_digit(*strp)) { 821 /* 822 ** Day of year. 823 */ 824 rulep->r_type = DAY_OF_YEAR; 825 strp = getnum(strp, &rulep->r_day, 0, DAYSPERLYEAR - 1); 826 } else return NULL; /* invalid format */ 827 if (strp == NULL) 828 return NULL; 829 if (*strp == '/') { 830 /* 831 ** Time specified. 832 */ 833 ++strp; 834 strp = getoffset(strp, &rulep->r_time); 835 } else rulep->r_time = 2 * SECSPERHOUR; /* default = 2:00:00 */ 836 return strp; 837 } 838 839 /* 840 ** Given a year, a rule, and the offset from UT at the time that rule takes 841 ** effect, calculate the year-relative time that rule takes effect. 842 */ 843 844 static int_fast32_t 845 transtime(const int year, const struct rule * const rulep, 846 const int_fast32_t offset) 847 { 848 int leapyear; 849 int_fast32_t value; 850 int i; 851 int d, m1, yy0, yy1, yy2, dow; 852 853 INITIALIZE(value); 854 leapyear = isleap(year); 855 switch (rulep->r_type) { 856 857 case JULIAN_DAY: 858 /* 859 ** Jn - Julian day, 1 == January 1, 60 == March 1 even in leap 860 ** years. 861 ** In non-leap years, or if the day number is 59 or less, just 862 ** add SECSPERDAY times the day number-1 to the time of 863 ** January 1, midnight, to get the day. 864 */ 865 value = (rulep->r_day - 1) * SECSPERDAY; 866 if (leapyear && rulep->r_day >= 60) 867 value += SECSPERDAY; 868 break; 869 870 case DAY_OF_YEAR: 871 /* 872 ** n - day of year. 873 ** Just add SECSPERDAY times the day number to the time of 874 ** January 1, midnight, to get the day. 875 */ 876 value = rulep->r_day * SECSPERDAY; 877 break; 878 879 case MONTH_NTH_DAY_OF_WEEK: 880 /* 881 ** Mm.n.d - nth "dth day" of month m. 882 */ 883 884 /* 885 ** Use Zeller's Congruence to get day-of-week of first day of 886 ** month. 887 */ 888 m1 = (rulep->r_mon + 9) % 12 + 1; 889 yy0 = (rulep->r_mon <= 2) ? (year - 1) : year; 890 yy1 = yy0 / 100; 891 yy2 = yy0 % 100; 892 dow = ((26 * m1 - 2) / 10 + 893 1 + yy2 + yy2 / 4 + yy1 / 4 - 2 * yy1) % 7; 894 if (dow < 0) 895 dow += DAYSPERWEEK; 896 897 /* 898 ** "dow" is the day-of-week of the first day of the month. Get 899 ** the day-of-month (zero-origin) of the first "dow" day of the 900 ** month. 901 */ 902 d = rulep->r_day - dow; 903 if (d < 0) 904 d += DAYSPERWEEK; 905 for (i = 1; i < rulep->r_week; ++i) { 906 if (d + DAYSPERWEEK >= 907 mon_lengths[leapyear][rulep->r_mon - 1]) 908 break; 909 d += DAYSPERWEEK; 910 } 911 912 /* 913 ** "d" is the day-of-month (zero-origin) of the day we want. 914 */ 915 value = d * SECSPERDAY; 916 for (i = 0; i < rulep->r_mon - 1; ++i) 917 value += mon_lengths[leapyear][i] * SECSPERDAY; 918 break; 919 } 920 921 /* 922 ** "value" is the year-relative time of 00:00:00 UT on the day in 923 ** question. To get the year-relative time of the specified local 924 ** time on that day, add the transition time and the current offset 925 ** from UT. 926 */ 927 return value + rulep->r_time + offset; 928 } 929 930 /* 931 ** Given a POSIX section 8-style TZ string, fill in the rule tables as 932 ** appropriate. 933 */ 934 935 static int 936 tzparse(const char *name, struct state * const sp, const int lastditch) 937 { 938 const char * stdname; 939 const char * dstname; 940 size_t stdlen; 941 size_t dstlen; 942 int_fast32_t stdoffset; 943 int_fast32_t dstoffset; 944 char * cp; 945 int load_result; 946 static struct ttinfo zttinfo; 947 948 INITIALIZE(dstname); 949 stdname = name; 950 if (lastditch) { 951 stdlen = strlen(name); /* length of standard zone name */ 952 name += stdlen; 953 if (stdlen >= sizeof sp->chars) 954 stdlen = (sizeof sp->chars) - 1; 955 stdoffset = 0; 956 } else { 957 if (*name == '<') { 958 name++; 959 stdname = name; 960 name = getqzname(name, '>'); 961 if (*name != '>') 962 return (-1); 963 stdlen = name - stdname; 964 name++; 965 } else { 966 name = getzname(name); 967 stdlen = name - stdname; 968 } 969 if (*name == '\0') 970 return -1; 971 name = getoffset(name, &stdoffset); 972 if (name == NULL) 973 return -1; 974 } 975 load_result = tzload(TZDEFRULES, sp, FALSE); 976 if (load_result != 0) 977 sp->leapcnt = 0; /* so, we're off a little */ 978 if (*name != '\0') { 979 if (*name == '<') { 980 dstname = ++name; 981 name = getqzname(name, '>'); 982 if (*name != '>') 983 return -1; 984 dstlen = name - dstname; 985 name++; 986 } else { 987 dstname = name; 988 name = getzname(name); 989 dstlen = name - dstname; /* length of DST zone name */ 990 } 991 if (*name != '\0' && *name != ',' && *name != ';') { 992 name = getoffset(name, &dstoffset); 993 if (name == NULL) 994 return -1; 995 } else dstoffset = stdoffset - SECSPERHOUR; 996 if (*name == '\0' && load_result != 0) 997 name = TZDEFRULESTRING; 998 if (*name == ',' || *name == ';') { 999 struct rule start; 1000 struct rule end; 1001 int year; 1002 int yearlim; 1003 int timecnt; 1004 time_t janfirst; 1005 1006 ++name; 1007 if ((name = getrule(name, &start)) == NULL) 1008 return -1; 1009 if (*name++ != ',') 1010 return -1; 1011 if ((name = getrule(name, &end)) == NULL) 1012 return -1; 1013 if (*name != '\0') 1014 return -1; 1015 sp->typecnt = 2; /* standard time and DST */ 1016 /* 1017 ** Two transitions per year, from EPOCH_YEAR forward. 1018 */ 1019 sp->ttis[0] = sp->ttis[1] = zttinfo; 1020 sp->ttis[0].tt_gmtoff = -dstoffset; 1021 sp->ttis[0].tt_isdst = 1; 1022 sp->ttis[0].tt_abbrind = stdlen + 1; 1023 sp->ttis[1].tt_gmtoff = -stdoffset; 1024 sp->ttis[1].tt_isdst = 0; 1025 sp->ttis[1].tt_abbrind = 0; 1026 timecnt = 0; 1027 janfirst = 0; 1028 yearlim = EPOCH_YEAR + YEARSPERREPEAT; 1029 for (year = EPOCH_YEAR; year < yearlim; year++) { 1030 int_fast32_t 1031 starttime = transtime(year, &start, stdoffset), 1032 endtime = transtime(year, &end, dstoffset); 1033 int_fast32_t 1034 yearsecs = (year_lengths[isleap(year)] 1035 * SECSPERDAY); 1036 int reversed = endtime < starttime; 1037 if (reversed) { 1038 int_fast32_t swap = starttime; 1039 starttime = endtime; 1040 endtime = swap; 1041 } 1042 if (reversed 1043 || (starttime < endtime 1044 && (endtime - starttime 1045 < (yearsecs 1046 + (stdoffset - dstoffset))))) { 1047 if (TZ_MAX_TIMES - 2 < timecnt) 1048 break; 1049 yearlim = year + YEARSPERREPEAT + 1; 1050 sp->ats[timecnt] = janfirst; 1051 if (increment_overflow_time 1052 (&sp->ats[timecnt], starttime)) 1053 break; 1054 sp->types[timecnt++] = reversed; 1055 sp->ats[timecnt] = janfirst; 1056 if (increment_overflow_time 1057 (&sp->ats[timecnt], endtime)) 1058 break; 1059 sp->types[timecnt++] = !reversed; 1060 } 1061 if (increment_overflow_time(&janfirst, yearsecs)) 1062 break; 1063 } 1064 sp->timecnt = timecnt; 1065 if (!timecnt) 1066 sp->typecnt = 1; /* Perpetual DST. */ 1067 } else { 1068 int_fast32_t theirstdoffset; 1069 int_fast32_t theirdstoffset; 1070 int_fast32_t theiroffset; 1071 int isdst; 1072 int i; 1073 int j; 1074 1075 if (*name != '\0') 1076 return -1; 1077 /* 1078 ** Initial values of theirstdoffset and theirdstoffset. 1079 */ 1080 theirstdoffset = 0; 1081 for (i = 0; i < sp->timecnt; ++i) { 1082 j = sp->types[i]; 1083 if (!sp->ttis[j].tt_isdst) { 1084 theirstdoffset = 1085 -sp->ttis[j].tt_gmtoff; 1086 break; 1087 } 1088 } 1089 theirdstoffset = 0; 1090 for (i = 0; i < sp->timecnt; ++i) { 1091 j = sp->types[i]; 1092 if (sp->ttis[j].tt_isdst) { 1093 theirdstoffset = 1094 -sp->ttis[j].tt_gmtoff; 1095 break; 1096 } 1097 } 1098 /* 1099 ** Initially we're assumed to be in standard time. 1100 */ 1101 isdst = FALSE; 1102 theiroffset = theirstdoffset; 1103 /* 1104 ** Now juggle transition times and types 1105 ** tracking offsets as you do. 1106 */ 1107 for (i = 0; i < sp->timecnt; ++i) { 1108 j = sp->types[i]; 1109 sp->types[i] = sp->ttis[j].tt_isdst; 1110 if (sp->ttis[j].tt_ttisgmt) { 1111 /* No adjustment to transition time */ 1112 } else { 1113 /* 1114 ** If summer time is in effect, and the 1115 ** transition time was not specified as 1116 ** standard time, add the summer time 1117 ** offset to the transition time; 1118 ** otherwise, add the standard time 1119 ** offset to the transition time. 1120 */ 1121 /* 1122 ** Transitions from DST to DDST 1123 ** will effectively disappear since 1124 ** POSIX provides for only one DST 1125 ** offset. 1126 */ 1127 if (isdst && !sp->ttis[j].tt_ttisstd) { 1128 sp->ats[i] += dstoffset - 1129 theirdstoffset; 1130 } else { 1131 sp->ats[i] += stdoffset - 1132 theirstdoffset; 1133 } 1134 } 1135 theiroffset = -sp->ttis[j].tt_gmtoff; 1136 if (sp->ttis[j].tt_isdst) 1137 theirdstoffset = theiroffset; 1138 else theirstdoffset = theiroffset; 1139 } 1140 /* 1141 ** Finally, fill in ttis. 1142 */ 1143 sp->ttis[0] = sp->ttis[1] = zttinfo; 1144 sp->ttis[0].tt_gmtoff = -stdoffset; 1145 sp->ttis[0].tt_isdst = FALSE; 1146 sp->ttis[0].tt_abbrind = 0; 1147 sp->ttis[1].tt_gmtoff = -dstoffset; 1148 sp->ttis[1].tt_isdst = TRUE; 1149 sp->ttis[1].tt_abbrind = stdlen + 1; 1150 sp->typecnt = 2; 1151 } 1152 } else { 1153 dstlen = 0; 1154 sp->typecnt = 1; /* only standard time */ 1155 sp->timecnt = 0; 1156 sp->ttis[0] = zttinfo; 1157 sp->ttis[0].tt_gmtoff = -stdoffset; 1158 sp->ttis[0].tt_isdst = 0; 1159 sp->ttis[0].tt_abbrind = 0; 1160 } 1161 sp->charcnt = stdlen + 1; 1162 if (dstlen != 0) 1163 sp->charcnt += dstlen + 1; 1164 if ((size_t) sp->charcnt > sizeof sp->chars) 1165 return -1; 1166 cp = sp->chars; 1167 strncpy(cp, stdname, stdlen); 1168 cp += stdlen; 1169 *cp++ = '\0'; 1170 if (dstlen != 0) { 1171 strncpy(cp, dstname, dstlen); 1172 *(cp + dstlen) = '\0'; 1173 } 1174 return 0; 1175 } 1176 1177 static void 1178 gmtload(struct state * const sp) 1179 { 1180 if (tzload(gmt, sp, TRUE) != 0) 1181 tzparse(gmt, sp, TRUE); 1182 } 1183 1184 static void 1185 tzsetwall_basic(int rdlocked) 1186 { 1187 if (!rdlocked) 1188 _RWLOCK_RDLOCK(&lcl_rwlock); 1189 if (lcl_is_set < 0) { 1190 if (!rdlocked) 1191 _RWLOCK_UNLOCK(&lcl_rwlock); 1192 return; 1193 } 1194 _RWLOCK_UNLOCK(&lcl_rwlock); 1195 1196 _RWLOCK_WRLOCK(&lcl_rwlock); 1197 lcl_is_set = -1; 1198 1199 if (tzload(NULL, lclptr, TRUE) != 0) 1200 gmtload(lclptr); 1201 settzname(); 1202 _RWLOCK_UNLOCK(&lcl_rwlock); 1203 1204 if (rdlocked) 1205 _RWLOCK_RDLOCK(&lcl_rwlock); 1206 } 1207 1208 void 1209 tzsetwall(void) 1210 { 1211 tzsetwall_basic(0); 1212 } 1213 1214 static void 1215 tzset_basic(int rdlocked) 1216 { 1217 const char * name; 1218 1219 name = getenv("TZ"); 1220 if (name == NULL) { 1221 tzsetwall_basic(rdlocked); 1222 return; 1223 } 1224 1225 if (!rdlocked) 1226 _RWLOCK_RDLOCK(&lcl_rwlock); 1227 if (lcl_is_set > 0 && strcmp(lcl_TZname, name) == 0) { 1228 if (!rdlocked) 1229 _RWLOCK_UNLOCK(&lcl_rwlock); 1230 return; 1231 } 1232 _RWLOCK_UNLOCK(&lcl_rwlock); 1233 1234 _RWLOCK_WRLOCK(&lcl_rwlock); 1235 lcl_is_set = strlen(name) < sizeof lcl_TZname; 1236 if (lcl_is_set) 1237 strcpy(lcl_TZname, name); 1238 1239 if (*name == '\0') { 1240 /* 1241 ** User wants it fast rather than right. 1242 */ 1243 lclptr->leapcnt = 0; /* so, we're off a little */ 1244 lclptr->timecnt = 0; 1245 lclptr->typecnt = 0; 1246 lclptr->ttis[0].tt_isdst = 0; 1247 lclptr->ttis[0].tt_gmtoff = 0; 1248 lclptr->ttis[0].tt_abbrind = 0; 1249 strcpy(lclptr->chars, gmt); 1250 } else if (tzload(name, lclptr, TRUE) != 0) 1251 if (name[0] == ':' || tzparse(name, lclptr, FALSE) != 0) 1252 gmtload(lclptr); 1253 settzname(); 1254 _RWLOCK_UNLOCK(&lcl_rwlock); 1255 1256 if (rdlocked) 1257 _RWLOCK_RDLOCK(&lcl_rwlock); 1258 } 1259 1260 void 1261 tzset(void) 1262 { 1263 tzset_basic(0); 1264 } 1265 1266 /* 1267 ** The easy way to behave "as if no library function calls" localtime 1268 ** is to not call it--so we drop its guts into "localsub", which can be 1269 ** freely called. (And no, the PANS doesn't require the above behavior-- 1270 ** but it *is* desirable.) 1271 ** 1272 ** The unused offset argument is for the benefit of mktime variants. 1273 */ 1274 1275 /*ARGSUSED*/ 1276 static struct tm * 1277 localsub(const time_t * const timep, const int_fast32_t offset __unused, 1278 struct tm * const tmp) 1279 { 1280 struct state * sp; 1281 const struct ttinfo * ttisp; 1282 int i; 1283 struct tm * result; 1284 const time_t t = *timep; 1285 1286 sp = lclptr; 1287 1288 if ((sp->goback && t < sp->ats[0]) || 1289 (sp->goahead && t > sp->ats[sp->timecnt - 1])) { 1290 time_t newt = t; 1291 time_t seconds; 1292 time_t years; 1293 1294 if (t < sp->ats[0]) 1295 seconds = sp->ats[0] - t; 1296 else seconds = t - sp->ats[sp->timecnt - 1]; 1297 --seconds; 1298 years = (seconds / SECSPERREPEAT + 1) * YEARSPERREPEAT; 1299 seconds = years * AVGSECSPERYEAR; 1300 if (t < sp->ats[0]) 1301 newt += seconds; 1302 else newt -= seconds; 1303 if (newt < sp->ats[0] || 1304 newt > sp->ats[sp->timecnt - 1]) 1305 return NULL; /* "cannot happen" */ 1306 result = localsub(&newt, offset, tmp); 1307 if (result == tmp) { 1308 time_t newy; 1309 1310 newy = tmp->tm_year; 1311 if (t < sp->ats[0]) 1312 newy -= years; 1313 else newy += years; 1314 tmp->tm_year = newy; 1315 if (tmp->tm_year != newy) 1316 return NULL; 1317 } 1318 return result; 1319 } 1320 if (sp->timecnt == 0 || t < sp->ats[0]) { 1321 i = sp->defaulttype; 1322 } else { 1323 int lo = 1; 1324 int hi = sp->timecnt; 1325 1326 while (lo < hi) { 1327 int mid = (lo + hi) >> 1; 1328 1329 if (t < sp->ats[mid]) 1330 hi = mid; 1331 else lo = mid + 1; 1332 } 1333 i = (int) sp->types[lo - 1]; 1334 } 1335 ttisp = &sp->ttis[i]; 1336 /* 1337 ** To get (wrong) behavior that's compatible with System V Release 2.0 1338 ** you'd replace the statement below with 1339 ** t += ttisp->tt_gmtoff; 1340 ** timesub(&t, 0L, sp, tmp); 1341 */ 1342 result = timesub(&t, ttisp->tt_gmtoff, sp, tmp); 1343 tmp->tm_isdst = ttisp->tt_isdst; 1344 tzname[tmp->tm_isdst] = &sp->chars[ttisp->tt_abbrind]; 1345 #ifdef TM_ZONE 1346 tmp->TM_ZONE = &sp->chars[ttisp->tt_abbrind]; 1347 #endif /* defined TM_ZONE */ 1348 return result; 1349 } 1350 1351 static void 1352 localtime_key_init(void) 1353 { 1354 1355 localtime_key_error = _pthread_key_create(&localtime_key, free); 1356 } 1357 1358 struct tm * 1359 localtime(const time_t * const timep) 1360 { 1361 struct tm *p_tm; 1362 1363 if (__isthreaded != 0) { 1364 _pthread_once(&localtime_once, localtime_key_init); 1365 if (localtime_key_error != 0) { 1366 errno = localtime_key_error; 1367 return(NULL); 1368 } 1369 p_tm = _pthread_getspecific(localtime_key); 1370 if (p_tm == NULL) { 1371 if ((p_tm = (struct tm *)malloc(sizeof(struct tm))) 1372 == NULL) 1373 return(NULL); 1374 _pthread_setspecific(localtime_key, p_tm); 1375 } 1376 _RWLOCK_RDLOCK(&lcl_rwlock); 1377 tzset_basic(1); 1378 localsub(timep, 0L, p_tm); 1379 _RWLOCK_UNLOCK(&lcl_rwlock); 1380 return(p_tm); 1381 } else { 1382 tzset_basic(0); 1383 localsub(timep, 0L, &tm); 1384 return(&tm); 1385 } 1386 } 1387 1388 /* 1389 ** Re-entrant version of localtime. 1390 */ 1391 1392 struct tm * 1393 localtime_r(const time_t * const timep, struct tm *tmp) 1394 { 1395 _RWLOCK_RDLOCK(&lcl_rwlock); 1396 tzset_basic(1); 1397 localsub(timep, 0L, tmp); 1398 _RWLOCK_UNLOCK(&lcl_rwlock); 1399 return tmp; 1400 } 1401 1402 static void 1403 gmt_init(void) 1404 { 1405 gmtload(gmtptr); 1406 } 1407 1408 /* 1409 ** gmtsub is to gmtime as localsub is to localtime. 1410 */ 1411 1412 static struct tm * 1413 gmtsub(const time_t * const timep, const int_fast32_t offset, 1414 struct tm * const tmp) 1415 { 1416 struct tm * result; 1417 1418 _once(&gmt_once, gmt_init); 1419 result = timesub(timep, offset, gmtptr, tmp); 1420 #ifdef TM_ZONE 1421 /* 1422 ** Could get fancy here and deliver something such as 1423 ** "UT+xxxx" or "UT-xxxx" if offset is non-zero, 1424 ** but this is no time for a treasure hunt. 1425 */ 1426 if (offset != 0) 1427 tmp->TM_ZONE = wildabbr; 1428 else 1429 tmp->TM_ZONE = gmtptr->chars; 1430 #endif /* defined TM_ZONE */ 1431 return result; 1432 } 1433 1434 static void 1435 gmtime_key_init(void) 1436 { 1437 gmtime_key_error = _pthread_key_create(&gmtime_key, free); 1438 } 1439 1440 struct tm * 1441 gmtime(const time_t * const timep) 1442 { 1443 struct tm *p_tm; 1444 1445 if (__isthreaded != 0) { 1446 _pthread_once(&gmtime_once, gmtime_key_init); 1447 if (gmtime_key_error != 0) { 1448 errno = gmtime_key_error; 1449 return(NULL); 1450 } 1451 /* 1452 * Changed to follow POSIX.1 threads standard, which 1453 * is what BSD currently has. 1454 */ 1455 if ((p_tm = _pthread_getspecific(gmtime_key)) == NULL) { 1456 if ((p_tm = (struct tm *)malloc(sizeof(struct tm))) 1457 == NULL) { 1458 return(NULL); 1459 } 1460 _pthread_setspecific(gmtime_key, p_tm); 1461 } 1462 return gmtsub(timep, 0L, p_tm); 1463 } else { 1464 return gmtsub(timep, 0L, &tm); 1465 } 1466 } 1467 1468 /* 1469 * Re-entrant version of gmtime. 1470 */ 1471 1472 struct tm * 1473 gmtime_r(const time_t * timep, struct tm * tmp) 1474 { 1475 return gmtsub(timep, 0L, tmp); 1476 } 1477 1478 struct tm * 1479 offtime(const time_t * const timep, const long offset) 1480 { 1481 return gmtsub(timep, offset, &tm); 1482 } 1483 1484 /* 1485 ** Return the number of leap years through the end of the given year 1486 ** where, to make the math easy, the answer for year zero is defined as zero. 1487 */ 1488 1489 static int 1490 leaps_thru_end_of(const int y) 1491 { 1492 return (y >= 0) ? (y / 4 - y / 100 + y / 400) : 1493 -(leaps_thru_end_of(-(y + 1)) + 1); 1494 } 1495 1496 static struct tm * 1497 timesub(const time_t * const timep, const int_fast32_t offset, 1498 const struct state * const sp, struct tm * const tmp) 1499 { 1500 const struct lsinfo * lp; 1501 time_t tdays; 1502 int idays; /* unsigned would be so 2003 */ 1503 int_fast64_t rem; 1504 int y; 1505 const int * ip; 1506 int_fast64_t corr; 1507 int hit; 1508 int i; 1509 1510 corr = 0; 1511 hit = 0; 1512 i = sp->leapcnt; 1513 1514 while (--i >= 0) { 1515 lp = &sp->lsis[i]; 1516 if (*timep >= lp->ls_trans) { 1517 if (*timep == lp->ls_trans) { 1518 hit = ((i == 0 && lp->ls_corr > 0) || 1519 lp->ls_corr > sp->lsis[i - 1].ls_corr); 1520 if (hit) 1521 while (i > 0 && 1522 sp->lsis[i].ls_trans == 1523 sp->lsis[i - 1].ls_trans + 1 && 1524 sp->lsis[i].ls_corr == 1525 sp->lsis[i - 1].ls_corr + 1) { 1526 ++hit; 1527 --i; 1528 } 1529 } 1530 corr = lp->ls_corr; 1531 break; 1532 } 1533 } 1534 y = EPOCH_YEAR; 1535 tdays = *timep / SECSPERDAY; 1536 rem = *timep - tdays * SECSPERDAY; 1537 while (tdays < 0 || tdays >= year_lengths[isleap(y)]) { 1538 int newy; 1539 time_t tdelta; 1540 int idelta; 1541 int leapdays; 1542 1543 tdelta = tdays / DAYSPERLYEAR; 1544 if (! ((! TYPE_SIGNED(time_t) || INT_MIN <= tdelta) 1545 && tdelta <= INT_MAX)) 1546 return NULL; 1547 idelta = tdelta; 1548 if (idelta == 0) 1549 idelta = (tdays < 0) ? -1 : 1; 1550 newy = y; 1551 if (increment_overflow(&newy, idelta)) 1552 return NULL; 1553 leapdays = leaps_thru_end_of(newy - 1) - 1554 leaps_thru_end_of(y - 1); 1555 tdays -= ((time_t) newy - y) * DAYSPERNYEAR; 1556 tdays -= leapdays; 1557 y = newy; 1558 } 1559 { 1560 int_fast32_t seconds; 1561 1562 seconds = tdays * SECSPERDAY; 1563 tdays = seconds / SECSPERDAY; 1564 rem += seconds - tdays * SECSPERDAY; 1565 } 1566 /* 1567 ** Given the range, we can now fearlessly cast... 1568 */ 1569 idays = tdays; 1570 rem += offset - corr; 1571 while (rem < 0) { 1572 rem += SECSPERDAY; 1573 --idays; 1574 } 1575 while (rem >= SECSPERDAY) { 1576 rem -= SECSPERDAY; 1577 ++idays; 1578 } 1579 while (idays < 0) { 1580 if (increment_overflow(&y, -1)) 1581 return NULL; 1582 idays += year_lengths[isleap(y)]; 1583 } 1584 while (idays >= year_lengths[isleap(y)]) { 1585 idays -= year_lengths[isleap(y)]; 1586 if (increment_overflow(&y, 1)) 1587 return NULL; 1588 } 1589 tmp->tm_year = y; 1590 if (increment_overflow(&tmp->tm_year, -TM_YEAR_BASE)) 1591 return NULL; 1592 tmp->tm_yday = idays; 1593 /* 1594 ** The "extra" mods below avoid overflow problems. 1595 */ 1596 tmp->tm_wday = EPOCH_WDAY + 1597 ((y - EPOCH_YEAR) % DAYSPERWEEK) * 1598 (DAYSPERNYEAR % DAYSPERWEEK) + 1599 leaps_thru_end_of(y - 1) - 1600 leaps_thru_end_of(EPOCH_YEAR - 1) + 1601 idays; 1602 tmp->tm_wday %= DAYSPERWEEK; 1603 if (tmp->tm_wday < 0) 1604 tmp->tm_wday += DAYSPERWEEK; 1605 tmp->tm_hour = (int) (rem / SECSPERHOUR); 1606 rem %= SECSPERHOUR; 1607 tmp->tm_min = (int) (rem / SECSPERMIN); 1608 /* 1609 ** A positive leap second requires a special 1610 ** representation. This uses "... ??:59:60" et seq. 1611 */ 1612 tmp->tm_sec = (int) (rem % SECSPERMIN) + hit; 1613 ip = mon_lengths[isleap(y)]; 1614 for (tmp->tm_mon = 0; idays >= ip[tmp->tm_mon]; ++(tmp->tm_mon)) 1615 idays -= ip[tmp->tm_mon]; 1616 tmp->tm_mday = (int) (idays + 1); 1617 tmp->tm_isdst = 0; 1618 #ifdef TM_GMTOFF 1619 tmp->TM_GMTOFF = offset; 1620 #endif /* defined TM_GMTOFF */ 1621 return tmp; 1622 } 1623 1624 char * 1625 ctime(const time_t * const timep) 1626 { 1627 /* 1628 ** Section 4.12.3.2 of X3.159-1989 requires that 1629 ** The ctime function converts the calendar time pointed to by timer 1630 ** to local time in the form of a string. It is equivalent to 1631 ** asctime(localtime(timer)) 1632 */ 1633 return asctime(localtime(timep)); 1634 } 1635 1636 char * 1637 ctime_r(const time_t * const timep, char *buf) 1638 { 1639 struct tm mytm; 1640 1641 return asctime_r(localtime_r(timep, &mytm), buf); 1642 } 1643 1644 /* 1645 ** Adapted from code provided by Robert Elz, who writes: 1646 ** The "best" way to do mktime I think is based on an idea of Bob 1647 ** Kridle's (so its said...) from a long time ago. 1648 ** It does a binary search of the time_t space. Since time_t's are 1649 ** just 32 bits, its a max of 32 iterations (even at 64 bits it 1650 ** would still be very reasonable). 1651 */ 1652 1653 #ifndef WRONG 1654 #define WRONG (-1) 1655 #endif /* !defined WRONG */ 1656 1657 /* 1658 ** Normalize logic courtesy Paul Eggert. 1659 */ 1660 1661 static int 1662 increment_overflow(int * const ip, int j) 1663 { 1664 int const i = *ip; 1665 1666 /* 1667 ** If i >= 0 there can only be overflow if i + j > INT_MAX 1668 ** or if j > INT_MAX - i; given i >= 0, INT_MAX - i cannot overflow. 1669 ** If i < 0 there can only be overflow if i + j < INT_MIN 1670 ** or if j < INT_MIN - i; given i < 0, INT_MIN - i cannot overflow. 1671 */ 1672 if ((i >= 0) ? (j > INT_MAX - i) : (j < INT_MIN - i)) 1673 return TRUE; 1674 *ip += j; 1675 return FALSE; 1676 } 1677 1678 static int 1679 increment_overflow32(int_fast32_t * const lp, int const m) 1680 { 1681 int_fast32_t const l = *lp; 1682 1683 if ((l >= 0) ? (m > INT_FAST32_MAX - l) : (m < INT_FAST32_MIN - l)) 1684 return TRUE; 1685 *lp += m; 1686 return FALSE; 1687 } 1688 1689 static int 1690 increment_overflow_time(time_t *tp, int_fast32_t j) 1691 { 1692 /* 1693 ** This is like 1694 ** 'if (! (time_t_min <= *tp + j && *tp + j <= time_t_max)) ...', 1695 ** except that it does the right thing even if *tp + j would overflow. 1696 */ 1697 if (! (j < 0 1698 ? (TYPE_SIGNED(time_t) ? time_t_min - j <= *tp : -1 - j < *tp) 1699 : *tp <= time_t_max - j)) 1700 return TRUE; 1701 *tp += j; 1702 return FALSE; 1703 } 1704 1705 static int 1706 normalize_overflow(int * const tensptr, int * const unitsptr, const int base) 1707 { 1708 int tensdelta; 1709 1710 tensdelta = (*unitsptr >= 0) ? 1711 (*unitsptr / base) : 1712 (-1 - (-1 - *unitsptr) / base); 1713 *unitsptr -= tensdelta * base; 1714 return increment_overflow(tensptr, tensdelta); 1715 } 1716 1717 static int 1718 normalize_overflow32(int_fast32_t * const tensptr, int * const unitsptr, 1719 const int base) 1720 { 1721 int tensdelta; 1722 1723 tensdelta = (*unitsptr >= 0) ? 1724 (*unitsptr / base) : 1725 (-1 - (-1 - *unitsptr) / base); 1726 *unitsptr -= tensdelta * base; 1727 return increment_overflow32(tensptr, tensdelta); 1728 } 1729 1730 static int 1731 tmcomp(const struct tm * const atmp, const struct tm * const btmp) 1732 { 1733 int result; 1734 1735 if (atmp->tm_year != btmp->tm_year) 1736 return atmp->tm_year < btmp->tm_year ? -1 : 1; 1737 if ((result = (atmp->tm_mon - btmp->tm_mon)) == 0 && 1738 (result = (atmp->tm_mday - btmp->tm_mday)) == 0 && 1739 (result = (atmp->tm_hour - btmp->tm_hour)) == 0 && 1740 (result = (atmp->tm_min - btmp->tm_min)) == 0) 1741 result = atmp->tm_sec - btmp->tm_sec; 1742 return result; 1743 } 1744 1745 static time_t 1746 time2sub(struct tm * const tmp, 1747 struct tm * (* const funcp)(const time_t *, int_fast32_t, struct tm *), 1748 const int_fast32_t offset, int * const okayp, const int do_norm_secs) 1749 { 1750 const struct state * sp; 1751 int dir; 1752 int i, j; 1753 int saved_seconds; 1754 int_fast32_t li; 1755 time_t lo; 1756 time_t hi; 1757 int_fast32_t y; 1758 time_t newt; 1759 time_t t; 1760 struct tm yourtm, mytm; 1761 1762 *okayp = FALSE; 1763 yourtm = *tmp; 1764 if (do_norm_secs) { 1765 if (normalize_overflow(&yourtm.tm_min, &yourtm.tm_sec, 1766 SECSPERMIN)) 1767 return WRONG; 1768 } 1769 if (normalize_overflow(&yourtm.tm_hour, &yourtm.tm_min, MINSPERHOUR)) 1770 return WRONG; 1771 if (normalize_overflow(&yourtm.tm_mday, &yourtm.tm_hour, HOURSPERDAY)) 1772 return WRONG; 1773 y = yourtm.tm_year; 1774 if (normalize_overflow32(&y, &yourtm.tm_mon, MONSPERYEAR)) 1775 return WRONG; 1776 /* 1777 ** Turn y into an actual year number for now. 1778 ** It is converted back to an offset from TM_YEAR_BASE later. 1779 */ 1780 if (increment_overflow32(&y, TM_YEAR_BASE)) 1781 return WRONG; 1782 while (yourtm.tm_mday <= 0) { 1783 if (increment_overflow32(&y, -1)) 1784 return WRONG; 1785 li = y + (1 < yourtm.tm_mon); 1786 yourtm.tm_mday += year_lengths[isleap(li)]; 1787 } 1788 while (yourtm.tm_mday > DAYSPERLYEAR) { 1789 li = y + (1 < yourtm.tm_mon); 1790 yourtm.tm_mday -= year_lengths[isleap(li)]; 1791 if (increment_overflow32(&y, 1)) 1792 return WRONG; 1793 } 1794 for ( ; ; ) { 1795 i = mon_lengths[isleap(y)][yourtm.tm_mon]; 1796 if (yourtm.tm_mday <= i) 1797 break; 1798 yourtm.tm_mday -= i; 1799 if (++yourtm.tm_mon >= MONSPERYEAR) { 1800 yourtm.tm_mon = 0; 1801 if (increment_overflow32(&y, 1)) 1802 return WRONG; 1803 } 1804 } 1805 if (increment_overflow32(&y, -TM_YEAR_BASE)) 1806 return WRONG; 1807 yourtm.tm_year = y; 1808 if (yourtm.tm_year != y) 1809 return WRONG; 1810 if (yourtm.tm_sec >= 0 && yourtm.tm_sec < SECSPERMIN) 1811 saved_seconds = 0; 1812 else if (y + TM_YEAR_BASE < EPOCH_YEAR) { 1813 /* 1814 ** We can't set tm_sec to 0, because that might push the 1815 ** time below the minimum representable time. 1816 ** Set tm_sec to 59 instead. 1817 ** This assumes that the minimum representable time is 1818 ** not in the same minute that a leap second was deleted from, 1819 ** which is a safer assumption than using 58 would be. 1820 */ 1821 if (increment_overflow(&yourtm.tm_sec, 1 - SECSPERMIN)) 1822 return WRONG; 1823 saved_seconds = yourtm.tm_sec; 1824 yourtm.tm_sec = SECSPERMIN - 1; 1825 } else { 1826 saved_seconds = yourtm.tm_sec; 1827 yourtm.tm_sec = 0; 1828 } 1829 /* 1830 ** Do a binary search (this works whatever time_t's type is). 1831 */ 1832 if (!TYPE_SIGNED(time_t)) { 1833 lo = 0; 1834 hi = lo - 1; 1835 } else { 1836 lo = 1; 1837 for (i = 0; i < (int) TYPE_BIT(time_t) - 1; ++i) 1838 lo *= 2; 1839 hi = -(lo + 1); 1840 } 1841 for ( ; ; ) { 1842 t = lo / 2 + hi / 2; 1843 if (t < lo) 1844 t = lo; 1845 else if (t > hi) 1846 t = hi; 1847 if ((*funcp)(&t, offset, &mytm) == NULL) { 1848 /* 1849 ** Assume that t is too extreme to be represented in 1850 ** a struct tm; arrange things so that it is less 1851 ** extreme on the next pass. 1852 */ 1853 dir = (t > 0) ? 1 : -1; 1854 } else dir = tmcomp(&mytm, &yourtm); 1855 if (dir != 0) { 1856 if (t == lo) { 1857 if (t == time_t_max) 1858 return WRONG; 1859 ++t; 1860 ++lo; 1861 } else if (t == hi) { 1862 if (t == time_t_min) 1863 return WRONG; 1864 --t; 1865 --hi; 1866 } 1867 if (lo > hi) 1868 return WRONG; 1869 if (dir > 0) 1870 hi = t; 1871 else lo = t; 1872 continue; 1873 } 1874 if (yourtm.tm_isdst < 0 || mytm.tm_isdst == yourtm.tm_isdst) 1875 break; 1876 /* 1877 ** Right time, wrong type. 1878 ** Hunt for right time, right type. 1879 ** It's okay to guess wrong since the guess 1880 ** gets checked. 1881 */ 1882 sp = (const struct state *) 1883 ((funcp == localsub) ? lclptr : gmtptr); 1884 1885 for (i = sp->typecnt - 1; i >= 0; --i) { 1886 if (sp->ttis[i].tt_isdst != yourtm.tm_isdst) 1887 continue; 1888 for (j = sp->typecnt - 1; j >= 0; --j) { 1889 if (sp->ttis[j].tt_isdst == yourtm.tm_isdst) 1890 continue; 1891 newt = t + sp->ttis[j].tt_gmtoff - 1892 sp->ttis[i].tt_gmtoff; 1893 if ((*funcp)(&newt, offset, &mytm) == NULL) 1894 continue; 1895 if (tmcomp(&mytm, &yourtm) != 0) 1896 continue; 1897 if (mytm.tm_isdst != yourtm.tm_isdst) 1898 continue; 1899 /* 1900 ** We have a match. 1901 */ 1902 t = newt; 1903 goto label; 1904 } 1905 } 1906 return WRONG; 1907 } 1908 label: 1909 newt = t + saved_seconds; 1910 if ((newt < t) != (saved_seconds < 0)) 1911 return WRONG; 1912 t = newt; 1913 if ((*funcp)(&t, offset, tmp)) 1914 *okayp = TRUE; 1915 return t; 1916 } 1917 1918 static time_t 1919 time2(struct tm * const tmp, 1920 struct tm * (* const funcp)(const time_t *, int_fast32_t, struct tm *), 1921 const int_fast32_t offset, int * const okayp) 1922 { 1923 time_t t; 1924 1925 /* 1926 ** First try without normalization of seconds 1927 ** (in case tm_sec contains a value associated with a leap second). 1928 ** If that fails, try with normalization of seconds. 1929 */ 1930 t = time2sub(tmp, funcp, offset, okayp, FALSE); 1931 return *okayp ? t : time2sub(tmp, funcp, offset, okayp, TRUE); 1932 } 1933 1934 static time_t 1935 time1(struct tm * const tmp, 1936 struct tm * (* const funcp)(const time_t *, int_fast32_t, struct tm *), 1937 const int_fast32_t offset) 1938 { 1939 time_t t; 1940 const struct state * sp; 1941 int samei, otheri; 1942 int sameind, otherind; 1943 int i; 1944 int nseen; 1945 int seen[TZ_MAX_TYPES]; 1946 int types[TZ_MAX_TYPES]; 1947 int okay; 1948 1949 if (tmp == NULL) { 1950 errno = EINVAL; 1951 return WRONG; 1952 } 1953 if (tmp->tm_isdst > 1) 1954 tmp->tm_isdst = 1; 1955 t = time2(tmp, funcp, offset, &okay); 1956 1957 /* 1958 ** PCTS code courtesy Grant Sullivan. 1959 */ 1960 if (okay) 1961 return t; 1962 if (tmp->tm_isdst < 0) 1963 tmp->tm_isdst = 0; /* reset to std and try again */ 1964 1965 /* 1966 ** We're supposed to assume that somebody took a time of one type 1967 ** and did some math on it that yielded a "struct tm" that's bad. 1968 ** We try to divine the type they started from and adjust to the 1969 ** type they need. 1970 */ 1971 sp = (const struct state *) ((funcp == localsub) ? lclptr : gmtptr); 1972 1973 for (i = 0; i < sp->typecnt; ++i) 1974 seen[i] = FALSE; 1975 nseen = 0; 1976 for (i = sp->timecnt - 1; i >= 0; --i) 1977 if (!seen[sp->types[i]]) { 1978 seen[sp->types[i]] = TRUE; 1979 types[nseen++] = sp->types[i]; 1980 } 1981 for (sameind = 0; sameind < nseen; ++sameind) { 1982 samei = types[sameind]; 1983 if (sp->ttis[samei].tt_isdst != tmp->tm_isdst) 1984 continue; 1985 for (otherind = 0; otherind < nseen; ++otherind) { 1986 otheri = types[otherind]; 1987 if (sp->ttis[otheri].tt_isdst == tmp->tm_isdst) 1988 continue; 1989 tmp->tm_sec += sp->ttis[otheri].tt_gmtoff - 1990 sp->ttis[samei].tt_gmtoff; 1991 tmp->tm_isdst = !tmp->tm_isdst; 1992 t = time2(tmp, funcp, offset, &okay); 1993 if (okay) 1994 return t; 1995 tmp->tm_sec -= sp->ttis[otheri].tt_gmtoff - 1996 sp->ttis[samei].tt_gmtoff; 1997 tmp->tm_isdst = !tmp->tm_isdst; 1998 } 1999 } 2000 return WRONG; 2001 } 2002 2003 time_t 2004 mktime(struct tm * const tmp) 2005 { 2006 time_t mktime_return_value; 2007 _RWLOCK_RDLOCK(&lcl_rwlock); 2008 tzset_basic(1); 2009 mktime_return_value = time1(tmp, localsub, 0L); 2010 _RWLOCK_UNLOCK(&lcl_rwlock); 2011 return(mktime_return_value); 2012 } 2013 2014 time_t 2015 timelocal(struct tm * const tmp) 2016 { 2017 if (tmp != NULL) 2018 tmp->tm_isdst = -1; /* in case it wasn't initialized */ 2019 return mktime(tmp); 2020 } 2021 2022 time_t 2023 timegm(struct tm * const tmp) 2024 { 2025 if (tmp != NULL) 2026 tmp->tm_isdst = 0; 2027 return time1(tmp, gmtsub, 0L); 2028 } 2029 2030 time_t 2031 timeoff(struct tm * const tmp, const long offset) 2032 { 2033 if (tmp != NULL) 2034 tmp->tm_isdst = 0; 2035 return time1(tmp, gmtsub, offset); 2036 } 2037 2038 /* 2039 ** XXX--is the below the right way to conditionalize?? 2040 */ 2041 2042 /* 2043 ** IEEE Std 1003.1-1988 (POSIX) legislates that 536457599 2044 ** shall correspond to "Wed Dec 31 23:59:59 UTC 1986", which 2045 ** is not the case if we are accounting for leap seconds. 2046 ** So, we provide the following conversion routines for use 2047 ** when exchanging timestamps with POSIX conforming systems. 2048 */ 2049 2050 static int_fast64_t 2051 leapcorr(time_t *timep) 2052 { 2053 struct state * sp; 2054 struct lsinfo * lp; 2055 int i; 2056 2057 sp = lclptr; 2058 i = sp->leapcnt; 2059 while (--i >= 0) { 2060 lp = &sp->lsis[i]; 2061 if (*timep >= lp->ls_trans) 2062 return lp->ls_corr; 2063 } 2064 return 0; 2065 } 2066 2067 time_t 2068 time2posix(time_t t) 2069 { 2070 tzset(); 2071 return t - leapcorr(&t); 2072 } 2073 2074 time_t 2075 posix2time(time_t t) 2076 { 2077 time_t x; 2078 time_t y; 2079 2080 tzset(); 2081 /* 2082 ** For a positive leap second hit, the result 2083 ** is not unique. For a negative leap second 2084 ** hit, the corresponding time doesn't exist, 2085 ** so we return an adjacent second. 2086 */ 2087 x = t + leapcorr(&t); 2088 y = x - leapcorr(&x); 2089 if (y < t) { 2090 do { 2091 x++; 2092 y = x - leapcorr(&x); 2093 } while (y < t); 2094 if (t != y) 2095 return x - 1; 2096 } else if (y > t) { 2097 do { 2098 --x; 2099 y = x - leapcorr(&x); 2100 } while (y > t); 2101 if (t != y) 2102 return x + 1; 2103 } 2104 return x; 2105 } 2106