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