1 /* 2 ** This file is in the public domain, so clarified as of 3 ** 1996-06-05 by Arthur David Olson. 4 ** 5 ** @(#)localtime.c 8.10 6 ** $FreeBSD: src/lib/libc/stdtime/localtime.c,v 1.25.2.2 2002/08/13 16:08:07 bmilekic Exp $ 7 */ 8 9 /* 10 ** Leap second handling from Bradley White. 11 ** POSIX-style TZ environment variable handling from Guy Harris. 12 */ 13 14 /*LINTLIBRARY*/ 15 16 #include "namespace.h" 17 #include <sys/types.h> 18 #include <sys/stat.h> 19 20 #include <fcntl.h> 21 #include <float.h> /* for FLT_MAX and DBL_MAX */ 22 #include <time.h> 23 #include <pthread.h> 24 #include "private.h" 25 #include <un-namespace.h> 26 27 #include "tzfile.h" 28 29 #include "libc_private.h" 30 31 #define _MUTEX_LOCK(x) if (__isthreaded) _pthread_mutex_lock(x) 32 #define _MUTEX_UNLOCK(x) if (__isthreaded) _pthread_mutex_unlock(x) 33 34 #define _RWLOCK_RDLOCK(x) \ 35 do { \ 36 if (__isthreaded) _pthread_rwlock_rdlock(x); \ 37 } while (0) 38 39 #define _RWLOCK_WRLOCK(x) \ 40 do { \ 41 if (__isthreaded) _pthread_rwlock_wrlock(x); \ 42 } while (0) 43 44 #define _RWLOCK_UNLOCK(x) \ 45 do { \ 46 if (__isthreaded) _pthread_rwlock_unlock(x); \ 47 } while (0) 48 49 #ifndef TZ_ABBR_MAX_LEN 50 #define TZ_ABBR_MAX_LEN 16 51 #endif /* !defined TZ_ABBR_MAX_LEN */ 52 53 #ifndef TZ_ABBR_CHAR_SET 54 #define TZ_ABBR_CHAR_SET \ 55 "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789 :+-._" 56 #endif /* !defined TZ_ABBR_CHAR_SET */ 57 58 #ifndef TZ_ABBR_ERR_CHAR 59 #define TZ_ABBR_ERR_CHAR '_' 60 #endif /* !defined TZ_ABBR_ERR_CHAR */ 61 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 83 static char wildabbr[] = WILDABBR; 84 85 static const char gmt[] = "UTC"; 86 87 /* 88 ** The DST rules to use if TZ has no rules and we can't load TZDEFRULES. 89 ** We default to US rules as of 1999-08-17. 90 ** POSIX 1003.1 section 8.1.1 says that the default DST rules are 91 ** implementation dependent; for historical reasons, US rules are a 92 ** common default. 93 */ 94 #ifndef TZDEFRULESTRING 95 #define TZDEFRULESTRING ",M4.1.0,M10.5.0" 96 #endif /* !defined TZDEFDST */ 97 98 struct ttinfo { /* time type information */ 99 long tt_gmtoff; /* UTC offset in seconds */ 100 int tt_isdst; /* used to set tm_isdst */ 101 int tt_abbrind; /* abbreviation list index */ 102 int tt_ttisstd; /* TRUE if transition is std time */ 103 int tt_ttisgmt; /* TRUE if transition is UTC */ 104 }; 105 106 struct lsinfo { /* leap second information */ 107 time_t ls_trans; /* transition time */ 108 long ls_corr; /* correction to apply */ 109 }; 110 111 #define BIGGEST(a, b) (((a) > (b)) ? (a) : (b)) 112 113 #ifdef TZNAME_MAX 114 #define MY_TZNAME_MAX TZNAME_MAX 115 #endif /* defined TZNAME_MAX */ 116 #ifndef TZNAME_MAX 117 #define MY_TZNAME_MAX 255 118 #endif /* !defined TZNAME_MAX */ 119 120 struct state { 121 int leapcnt; 122 int timecnt; 123 int typecnt; 124 int charcnt; 125 int goback; 126 int goahead; 127 time_t ats[TZ_MAX_TIMES]; 128 unsigned char types[TZ_MAX_TIMES]; 129 struct ttinfo ttis[TZ_MAX_TYPES]; 130 char chars[BIGGEST(BIGGEST(TZ_MAX_CHARS + 1, sizeof gmt), 131 (2 * (MY_TZNAME_MAX + 1)))]; 132 struct lsinfo lsis[TZ_MAX_LEAPS]; 133 }; 134 135 struct rule { 136 int r_type; /* type of rule--see below */ 137 int r_day; /* day number of rule */ 138 int r_week; /* week number of rule */ 139 int r_mon; /* month number of rule */ 140 long r_time; /* transition time of rule */ 141 }; 142 143 #define JULIAN_DAY 0 /* Jn - Julian day */ 144 #define DAY_OF_YEAR 1 /* n - day of year */ 145 #define MONTH_NTH_DAY_OF_WEEK 2 /* Mm.n.d - month, week, day of week */ 146 147 /* 148 ** Prototypes for static functions. 149 */ 150 151 static long detzcode(const char * codep); 152 static time_t detzcode64(const char * codep); 153 static int differ_by_repeat(time_t t1, time_t t0); 154 static const char * getzname(const char * strp); 155 static const char * getqzname(const char * strp, const int delim); 156 static const char * getnum(const char * strp, int * nump, int min, 157 int max); 158 static const char * getsecs(const char * strp, long * secsp); 159 static const char * getoffset(const char * strp, long * offsetp); 160 static const char * getrule(const char * strp, struct rule * rulep); 161 static void gmtload(struct state * sp); 162 static struct tm * gmtsub(const time_t * timep, long offset, 163 struct tm * tmp); 164 static struct tm * localsub(const time_t * timep, long offset, 165 struct tm * tmp); 166 static int increment_overflow(int * number, int delta); 167 static int leaps_thru_end_of(int y); 168 static int long_increment_overflow(long * number, int delta); 169 static int long_normalize_overflow(long * 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 long, struct tm *), 177 long offset); 178 static time_t time2(struct tm *tmp, 179 struct tm * (*funcp)(const time_t *, 180 long, struct tm*), 181 long offset, int * okayp); 182 static time_t time2sub(struct tm *tmp, 183 struct tm * (*funcp)(const time_t *, 184 long, struct tm*), 185 long offset, int * okayp, int do_norm_secs); 186 static struct tm * timesub(const time_t * timep, long offset, 187 const struct state * sp, struct tm * tmp); 188 static int tmcomp(const struct tm * atmp, 189 const struct tm * btmp); 190 static time_t transtime(time_t janfirst, int year, 191 const struct rule * rulep, long offset); 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 int gmt_is_set; 210 static pthread_rwlock_t lcl_rwlock = PTHREAD_RWLOCK_INITIALIZER; 211 static pthread_mutex_t gmt_mutex = PTHREAD_MUTEX_INITIALIZER; 212 213 char * tzname[2] = { 214 wildabbr, 215 wildabbr 216 }; 217 218 /* 219 ** Section 4.12.3 of X3.159-1989 requires that 220 ** Except for the strftime function, these functions [asctime, 221 ** ctime, gmtime, localtime] return values in one of two static 222 ** objects: a broken-down time structure and an array of char. 223 ** Thanks to Paul Eggert for noting this. 224 */ 225 226 static struct tm tm; 227 228 time_t timezone = 0; 229 int daylight = 0; 230 231 static long 232 detzcode(const char * const codep) 233 { 234 long result; 235 int i; 236 237 result = (codep[0] & 0x80) ? ~0L : 0; 238 for (i = 0; i < 4; ++i) 239 result = (result << 8) | (codep[i] & 0xff); 240 return result; 241 } 242 243 static time_t 244 detzcode64(const char * const codep) 245 { 246 time_t result; 247 int i; 248 249 result = (codep[0] & 0x80) ? (~(int_fast64_t) 0) : 0; 250 for (i = 0; i < 8; ++i) 251 result = result * 256 + (codep[i] & 0xff); 252 return result; 253 } 254 255 static void 256 settzname(void) 257 { 258 struct state * const sp = lclptr; 259 int i; 260 261 tzname[0] = wildabbr; 262 tzname[1] = wildabbr; 263 daylight = 0; 264 timezone = 0; 265 266 for (i = 0; i < sp->typecnt; ++i) { 267 const struct ttinfo * const ttisp = &sp->ttis[i]; 268 269 tzname[ttisp->tt_isdst] = 270 &sp->chars[ttisp->tt_abbrind]; 271 if (ttisp->tt_isdst) 272 daylight = 1; 273 if (i == 0 || !ttisp->tt_isdst) 274 timezone = -(ttisp->tt_gmtoff); 275 } 276 /* 277 ** And to get the latest zone names into tzname. . . 278 */ 279 for (i = 0; i < sp->timecnt; ++i) { 280 const struct ttinfo * const ttisp = 281 &sp->ttis[ 282 sp->types[i]]; 283 284 tzname[ttisp->tt_isdst] = 285 &sp->chars[ttisp->tt_abbrind]; 286 } 287 /* 288 ** Finally, scrub the abbreviations. 289 ** First, replace bogus characters. 290 */ 291 for (i = 0; i < sp->charcnt; ++i) 292 if (strchr(TZ_ABBR_CHAR_SET, sp->chars[i]) == NULL) 293 sp->chars[i] = TZ_ABBR_ERR_CHAR; 294 /* 295 ** Second, truncate long abbreviations. 296 */ 297 for (i = 0; i < sp->typecnt; ++i) { 298 const struct ttinfo * const ttisp = &sp->ttis[i]; 299 char * cp = &sp->chars[ttisp->tt_abbrind]; 300 301 if (strlen(cp) > TZ_ABBR_MAX_LEN && 302 strcmp(cp, GRANDPARENTED) != 0) 303 *(cp + TZ_ABBR_MAX_LEN) = '\0'; 304 } 305 } 306 307 static int 308 differ_by_repeat(const time_t t1, const time_t t0) 309 { 310 int_fast64_t _t0 = t0; 311 int_fast64_t _t1 = t1; 312 313 if (TYPE_INTEGRAL(time_t) && 314 TYPE_BIT(time_t) - TYPE_SIGNED(time_t) < SECSPERREPEAT_BITS) 315 return 0; 316 return _t1 - _t0 == SECSPERREPEAT; 317 } 318 319 static int 320 tzload(const char *name, struct state * const sp, const int doextend) 321 { 322 const char * p; 323 int i; 324 int fid; 325 int stored; 326 int nread; 327 union { 328 struct tzhead tzhead; 329 char buf[2 * sizeof(struct tzhead) + 330 2 * sizeof *sp + 331 4 * TZ_MAX_TIMES]; 332 } u; 333 334 /* XXX The following is from OpenBSD, and I'm not sure it is correct */ 335 if (name != NULL && issetugid() != 0) 336 if ((name[0] == ':' && name[1] == '/') || 337 name[0] == '/' || strchr(name, '.')) 338 name = NULL; 339 if (name == NULL && (name = TZDEFAULT) == NULL) 340 return -1; 341 { 342 int doaccess; 343 struct stat stab; 344 /* 345 ** Section 4.9.1 of the C standard says that 346 ** "FILENAME_MAX expands to an integral constant expression 347 ** that is the size needed for an array of char large enough 348 ** to hold the longest file name string that the implementation 349 ** guarantees can be opened." 350 */ 351 char fullname[FILENAME_MAX + 1]; 352 353 if (name[0] == ':') 354 ++name; 355 doaccess = name[0] == '/'; 356 if (!doaccess) { 357 if ((p = TZDIR) == NULL) 358 return -1; 359 if ((strlen(p) + 1 + strlen(name) + 1) >= sizeof fullname) 360 return -1; 361 strcpy(fullname, p); 362 strcat(fullname, "/"); 363 strcat(fullname, name); 364 /* 365 ** Set doaccess if '.' (as in "../") shows up in name. 366 */ 367 if (strchr(name, '.') != NULL) 368 doaccess = TRUE; 369 name = fullname; 370 } 371 if (doaccess && access(name, R_OK) != 0) 372 return -1; 373 if ((fid = _open(name, O_RDONLY)) == -1) 374 return -1; 375 if ((_fstat(fid, &stab) < 0) || !S_ISREG(stab.st_mode)) { 376 _close(fid); 377 return -1; 378 } 379 } 380 nread = read(fid, u.buf, sizeof u.buf); 381 if (close(fid) < 0 || nread <= 0) 382 return -1; 383 for (stored = 4; stored <= 8; stored *= 2) { 384 int ttisstdcnt; 385 int ttisgmtcnt; 386 387 ttisstdcnt = (int) detzcode(u.tzhead.tzh_ttisstdcnt); 388 ttisgmtcnt = (int) detzcode(u.tzhead.tzh_ttisgmtcnt); 389 sp->leapcnt = (int) detzcode(u.tzhead.tzh_leapcnt); 390 sp->timecnt = (int) detzcode(u.tzhead.tzh_timecnt); 391 sp->typecnt = (int) detzcode(u.tzhead.tzh_typecnt); 392 sp->charcnt = (int) detzcode(u.tzhead.tzh_charcnt); 393 p = u.tzhead.tzh_charcnt + sizeof u.tzhead.tzh_charcnt; 394 if (sp->leapcnt < 0 || sp->leapcnt > TZ_MAX_LEAPS || 395 sp->typecnt <= 0 || sp->typecnt > TZ_MAX_TYPES || 396 sp->timecnt < 0 || sp->timecnt > TZ_MAX_TIMES || 397 sp->charcnt < 0 || sp->charcnt > TZ_MAX_CHARS || 398 (ttisstdcnt != sp->typecnt && ttisstdcnt != 0) || 399 (ttisgmtcnt != sp->typecnt && ttisgmtcnt != 0)) 400 return -1; 401 if (nread - (p - u.buf) < 402 sp->timecnt * stored + /* ats */ 403 sp->timecnt + /* types */ 404 sp->typecnt * 6 + /* ttinfos */ 405 sp->charcnt + /* chars */ 406 sp->leapcnt * (stored + 4) + /* lsinfos */ 407 ttisstdcnt + /* ttisstds */ 408 ttisgmtcnt) /* ttisgmts */ 409 return -1; 410 for (i = 0; i < sp->timecnt; ++i) { 411 sp->ats[i] = (stored == 4) ? 412 detzcode(p) : detzcode64(p); 413 p += stored; 414 } 415 for (i = 0; i < sp->timecnt; ++i) { 416 sp->types[i] = (unsigned char) *p++; 417 if (sp->types[i] >= sp->typecnt) 418 return -1; 419 } 420 for (i = 0; i < sp->typecnt; ++i) { 421 struct ttinfo * ttisp; 422 423 ttisp = &sp->ttis[i]; 424 ttisp->tt_gmtoff = detzcode(p); 425 p += 4; 426 ttisp->tt_isdst = (unsigned char) *p++; 427 if (ttisp->tt_isdst != 0 && ttisp->tt_isdst != 1) 428 return -1; 429 ttisp->tt_abbrind = (unsigned char) *p++; 430 if (ttisp->tt_abbrind < 0 || 431 ttisp->tt_abbrind > sp->charcnt) 432 return -1; 433 } 434 for (i = 0; i < sp->charcnt; ++i) 435 sp->chars[i] = *p++; 436 sp->chars[i] = '\0'; /* ensure '\0' at end */ 437 for (i = 0; i < sp->leapcnt; ++i) { 438 struct lsinfo * lsisp; 439 440 lsisp = &sp->lsis[i]; 441 lsisp->ls_trans = (stored == 4) ? 442 detzcode(p) : detzcode64(p); 443 p += stored; 444 lsisp->ls_corr = detzcode(p); 445 p += 4; 446 } 447 for (i = 0; i < sp->typecnt; ++i) { 448 struct ttinfo * ttisp; 449 450 ttisp = &sp->ttis[i]; 451 if (ttisstdcnt == 0) 452 ttisp->tt_ttisstd = FALSE; 453 else { 454 ttisp->tt_ttisstd = *p++; 455 if (ttisp->tt_ttisstd != TRUE && 456 ttisp->tt_ttisstd != FALSE) 457 return -1; 458 } 459 } 460 for (i = 0; i < sp->typecnt; ++i) { 461 struct ttinfo * ttisp; 462 463 ttisp = &sp->ttis[i]; 464 if (ttisgmtcnt == 0) 465 ttisp->tt_ttisgmt = FALSE; 466 else { 467 ttisp->tt_ttisgmt = *p++; 468 if (ttisp->tt_ttisgmt != TRUE && 469 ttisp->tt_ttisgmt != FALSE) 470 return -1; 471 } 472 } 473 /* 474 ** Out-of-sort ats should mean we're running on a 475 ** signed time_t system but using a data file with 476 ** unsigned values (or vice versa). 477 */ 478 for (i = 0; i < sp->timecnt - 2; ++i) 479 if (sp->ats[i] > sp->ats[i + 1]) { 480 ++i; 481 if (TYPE_SIGNED(time_t)) { 482 /* 483 ** Ignore the end (easy). 484 */ 485 sp->timecnt = i; 486 } else { 487 /* 488 ** Ignore the beginning (harder). 489 */ 490 int j; 491 492 for (j = 0; j + i < sp->timecnt; ++j) { 493 sp->ats[j] = sp->ats[j + i]; 494 sp->types[j] = sp->types[j + i]; 495 } 496 sp->timecnt = j; 497 } 498 break; 499 } 500 /* 501 ** If this is an old file, we're done. 502 */ 503 if (u.tzhead.tzh_version[0] == '\0') 504 break; 505 nread -= p - u.buf; 506 for (i = 0; i < nread; ++i) 507 u.buf[i] = p[i]; 508 /* 509 ** If this is a narrow integer time_t system, we're done. 510 */ 511 if (stored >= (int) sizeof(time_t) && TYPE_INTEGRAL(time_t)) 512 break; 513 } 514 if (doextend && nread > 2 && 515 u.buf[0] == '\n' && u.buf[nread - 1] == '\n' && 516 sp->typecnt + 2 <= TZ_MAX_TYPES) { 517 struct state ts; 518 int result; 519 520 u.buf[nread - 1] = '\0'; 521 result = tzparse(&u.buf[1], &ts, FALSE); 522 if (result == 0 && ts.typecnt == 2 && 523 sp->charcnt + ts.charcnt <= TZ_MAX_CHARS) { 524 for (i = 0; i < 2; ++i) 525 ts.ttis[i].tt_abbrind += 526 sp->charcnt; 527 for (i = 0; i < ts.charcnt; ++i) 528 sp->chars[sp->charcnt++] = 529 ts.chars[i]; 530 i = 0; 531 while (i < ts.timecnt && 532 ts.ats[i] <= 533 sp->ats[sp->timecnt - 1]) 534 ++i; 535 while (i < ts.timecnt && 536 sp->timecnt < TZ_MAX_TIMES) { 537 sp->ats[sp->timecnt] = 538 ts.ats[i]; 539 sp->types[sp->timecnt] = 540 sp->typecnt + 541 ts.types[i]; 542 ++sp->timecnt; 543 ++i; 544 } 545 sp->ttis[sp->typecnt++] = ts.ttis[0]; 546 sp->ttis[sp->typecnt++] = ts.ttis[1]; 547 } 548 } 549 sp->goback = sp->goahead = FALSE; 550 if (sp->timecnt > 1) { 551 for (i = 1; i < sp->timecnt; ++i) 552 if (typesequiv(sp, sp->types[i], sp->types[0]) && 553 differ_by_repeat(sp->ats[i], sp->ats[0])) { 554 sp->goback = TRUE; 555 break; 556 } 557 for (i = sp->timecnt - 2; i >= 0; --i) 558 if (typesequiv(sp, sp->types[sp->timecnt - 1], 559 sp->types[i]) && 560 differ_by_repeat(sp->ats[sp->timecnt - 1], 561 sp->ats[i])) { 562 sp->goahead = TRUE; 563 break; 564 } 565 } 566 return 0; 567 } 568 569 static int 570 typesequiv(const struct state * const sp, const int a, const int b) 571 { 572 int result; 573 574 if (sp == NULL || 575 a < 0 || a >= sp->typecnt || 576 b < 0 || b >= sp->typecnt) 577 result = FALSE; 578 else { 579 const struct ttinfo * ap = &sp->ttis[a]; 580 const struct ttinfo * bp = &sp->ttis[b]; 581 result = ap->tt_gmtoff == bp->tt_gmtoff && 582 ap->tt_isdst == bp->tt_isdst && 583 ap->tt_ttisstd == bp->tt_ttisstd && 584 ap->tt_ttisgmt == bp->tt_ttisgmt && 585 strcmp(&sp->chars[ap->tt_abbrind], 586 &sp->chars[bp->tt_abbrind]) == 0; 587 } 588 return result; 589 } 590 591 static const int mon_lengths[2][MONSPERYEAR] = { 592 { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }, 593 { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 } 594 }; 595 596 static const int year_lengths[2] = { 597 DAYSPERNYEAR, DAYSPERLYEAR 598 }; 599 600 /* 601 ** Given a pointer into a time zone string, scan until a character that is not 602 ** a valid character in a zone name is found. Return a pointer to that 603 ** character. 604 */ 605 606 static const char * 607 getzname(const char *strp) 608 { 609 char c; 610 611 while ((c = *strp) != '\0' && !is_digit(c) && c != ',' && c != '-' && 612 c != '+') 613 ++strp; 614 return strp; 615 } 616 617 /* 618 ** Given a pointer into an extended time zone string, scan until the ending 619 ** delimiter of the zone name is located. Return a pointer to the delimiter. 620 ** 621 ** As with getzname above, the legal character set is actually quite 622 ** restricted, with other characters producing undefined results. 623 ** We don't do any checking here; checking is done later in common-case code. 624 */ 625 626 static const char * 627 getqzname(const char *strp, const int delim) 628 { 629 int c; 630 631 while ((c = *strp) != '\0' && c != delim) 632 ++strp; 633 return strp; 634 } 635 636 /* 637 ** Given a pointer into a time zone string, extract a number from that string. 638 ** Check that the number is within a specified range; if it is not, return 639 ** NULL. 640 ** Otherwise, return a pointer to the first character not part of the number. 641 */ 642 643 static const char * 644 getnum(const char *strp, int * const nump, const int min, const int max) 645 { 646 char c; 647 int num; 648 649 if (strp == NULL || !is_digit(c = *strp)) 650 return NULL; 651 num = 0; 652 do { 653 num = num * 10 + (c - '0'); 654 if (num > max) 655 return NULL; /* illegal value */ 656 c = *++strp; 657 } while (is_digit(c)); 658 if (num < min) 659 return NULL; /* illegal value */ 660 *nump = num; 661 return strp; 662 } 663 664 /* 665 ** Given a pointer into a time zone string, extract a number of seconds, 666 ** in hh[:mm[:ss]] form, from the string. 667 ** If any error occurs, return NULL. 668 ** Otherwise, return a pointer to the first character not part of the number 669 ** of seconds. 670 */ 671 672 static const char * 673 getsecs(const char *strp, long * const secsp) 674 { 675 int num; 676 677 /* 678 ** `HOURSPERDAY * DAYSPERWEEK - 1' allows quasi-Posix rules like 679 ** "M10.4.6/26", which does not conform to Posix, 680 ** but which specifies the equivalent of 681 ** ``02:00 on the first Sunday on or after 23 Oct''. 682 */ 683 strp = getnum(strp, &num, 0, HOURSPERDAY * DAYSPERWEEK - 1); 684 if (strp == NULL) 685 return NULL; 686 *secsp = num * (long) SECSPERHOUR; 687 if (*strp == ':') { 688 ++strp; 689 strp = getnum(strp, &num, 0, MINSPERHOUR - 1); 690 if (strp == NULL) 691 return NULL; 692 *secsp += num * SECSPERMIN; 693 if (*strp == ':') { 694 ++strp; 695 /* `SECSPERMIN' allows for leap seconds. */ 696 strp = getnum(strp, &num, 0, SECSPERMIN); 697 if (strp == NULL) 698 return NULL; 699 *secsp += num; 700 } 701 } 702 return strp; 703 } 704 705 /* 706 ** Given a pointer into a time zone string, extract an offset, in 707 ** [+-]hh[:mm[:ss]] form, from the string. 708 ** If any error occurs, return NULL. 709 ** Otherwise, return a pointer to the first character not part of the time. 710 */ 711 712 static const char * 713 getoffset(const char *strp, long * const offsetp) 714 { 715 int neg = 0; 716 717 if (*strp == '-') { 718 neg = 1; 719 ++strp; 720 } else if (*strp == '+') 721 ++strp; 722 strp = getsecs(strp, offsetp); 723 if (strp == NULL) 724 return NULL; /* illegal time */ 725 if (neg) 726 *offsetp = -*offsetp; 727 return strp; 728 } 729 730 /* 731 ** Given a pointer into a time zone string, extract a rule in the form 732 ** date[/time]. See POSIX section 8 for the format of "date" and "time". 733 ** If a valid rule is not found, return NULL. 734 ** Otherwise, return a pointer to the first character not part of the rule. 735 */ 736 737 static const char * 738 getrule(const char *strp, struct rule * const rulep) 739 { 740 if (*strp == 'J') { 741 /* 742 ** Julian day. 743 */ 744 rulep->r_type = JULIAN_DAY; 745 ++strp; 746 strp = getnum(strp, &rulep->r_day, 1, DAYSPERNYEAR); 747 } else if (*strp == 'M') { 748 /* 749 ** Month, week, day. 750 */ 751 rulep->r_type = MONTH_NTH_DAY_OF_WEEK; 752 ++strp; 753 strp = getnum(strp, &rulep->r_mon, 1, MONSPERYEAR); 754 if (strp == NULL) 755 return NULL; 756 if (*strp++ != '.') 757 return NULL; 758 strp = getnum(strp, &rulep->r_week, 1, 5); 759 if (strp == NULL) 760 return NULL; 761 if (*strp++ != '.') 762 return NULL; 763 strp = getnum(strp, &rulep->r_day, 0, DAYSPERWEEK - 1); 764 } else if (is_digit(*strp)) { 765 /* 766 ** Day of year. 767 */ 768 rulep->r_type = DAY_OF_YEAR; 769 strp = getnum(strp, &rulep->r_day, 0, DAYSPERLYEAR - 1); 770 } else return NULL; /* invalid format */ 771 if (strp == NULL) 772 return NULL; 773 if (*strp == '/') { 774 /* 775 ** Time specified. 776 */ 777 ++strp; 778 strp = getsecs(strp, &rulep->r_time); 779 } else rulep->r_time = 2 * SECSPERHOUR; /* default = 2:00:00 */ 780 return strp; 781 } 782 783 /* 784 ** Given the Epoch-relative time of January 1, 00:00:00 UTC, in a year, the 785 ** year, a rule, and the offset from UTC at the time that rule takes effect, 786 ** calculate the Epoch-relative time that rule takes effect. 787 */ 788 789 static time_t 790 transtime(const time_t janfirst, const int year, 791 const struct rule * const rulep, const long offset) 792 { 793 int leapyear; 794 time_t value; 795 int i; 796 int d, m1, yy0, yy1, yy2, dow; 797 798 INITIALIZE(value); 799 leapyear = isleap(year); 800 switch (rulep->r_type) { 801 802 case JULIAN_DAY: 803 /* 804 ** Jn - Julian day, 1 == January 1, 60 == March 1 even in leap 805 ** years. 806 ** In non-leap years, or if the day number is 59 or less, just 807 ** add SECSPERDAY times the day number-1 to the time of 808 ** January 1, midnight, to get the day. 809 */ 810 value = janfirst + (rulep->r_day - 1) * SECSPERDAY; 811 if (leapyear && rulep->r_day >= 60) 812 value += SECSPERDAY; 813 break; 814 815 case DAY_OF_YEAR: 816 /* 817 ** n - day of year. 818 ** Just add SECSPERDAY times the day number to the time of 819 ** January 1, midnight, to get the day. 820 */ 821 value = janfirst + rulep->r_day * SECSPERDAY; 822 break; 823 824 case MONTH_NTH_DAY_OF_WEEK: 825 /* 826 ** Mm.n.d - nth "dth day" of month m. 827 */ 828 value = janfirst; 829 for (i = 0; i < rulep->r_mon - 1; ++i) 830 value += mon_lengths[leapyear][i] * SECSPERDAY; 831 832 /* 833 ** Use Zeller's Congruence to get day-of-week of first day of 834 ** month. 835 */ 836 m1 = (rulep->r_mon + 9) % 12 + 1; 837 yy0 = (rulep->r_mon <= 2) ? (year - 1) : year; 838 yy1 = yy0 / 100; 839 yy2 = yy0 % 100; 840 dow = ((26 * m1 - 2) / 10 + 841 1 + yy2 + yy2 / 4 + yy1 / 4 - 2 * yy1) % 7; 842 if (dow < 0) 843 dow += DAYSPERWEEK; 844 845 /* 846 ** "dow" is the day-of-week of the first day of the month. Get 847 ** the day-of-month (zero-origin) of the first "dow" day of the 848 ** month. 849 */ 850 d = rulep->r_day - dow; 851 if (d < 0) 852 d += DAYSPERWEEK; 853 for (i = 1; i < rulep->r_week; ++i) { 854 if (d + DAYSPERWEEK >= 855 mon_lengths[leapyear][rulep->r_mon - 1]) 856 break; 857 d += DAYSPERWEEK; 858 } 859 860 /* 861 ** "d" is the day-of-month (zero-origin) of the day we want. 862 */ 863 value += d * SECSPERDAY; 864 break; 865 } 866 867 /* 868 ** "value" is the Epoch-relative time of 00:00:00 UTC on the day in 869 ** question. To get the Epoch-relative time of the specified local 870 ** time on that day, add the transition time and the current offset 871 ** from UTC. 872 */ 873 return value + rulep->r_time + offset; 874 } 875 876 /* 877 ** Given a POSIX section 8-style TZ string, fill in the rule tables as 878 ** appropriate. 879 */ 880 881 static int 882 tzparse(const char *name, struct state * const sp, const int lastditch) 883 { 884 const char * stdname; 885 const char * dstname; 886 size_t stdlen; 887 size_t dstlen; 888 long stdoffset; 889 long dstoffset; 890 time_t * atp; 891 unsigned char * typep; 892 char * cp; 893 int load_result; 894 895 INITIALIZE(dstname); 896 stdname = name; 897 if (lastditch) { 898 stdlen = strlen(name); /* length of standard zone name */ 899 name += stdlen; 900 if (stdlen >= sizeof sp->chars) 901 stdlen = (sizeof sp->chars) - 1; 902 stdoffset = 0; 903 } else { 904 if (*name == '<') { 905 name++; 906 stdname = name; 907 name = getqzname(name, '>'); 908 if (*name != '>') 909 return (-1); 910 stdlen = name - stdname; 911 name++; 912 } else { 913 name = getzname(name); 914 stdlen = name - stdname; 915 } 916 if (*name == '\0') 917 return -1; 918 name = getoffset(name, &stdoffset); 919 if (name == NULL) 920 return -1; 921 } 922 load_result = tzload(TZDEFRULES, sp, FALSE); 923 if (load_result != 0) 924 sp->leapcnt = 0; /* so, we're off a little */ 925 if (*name != '\0') { 926 if (*name == '<') { 927 dstname = ++name; 928 name = getqzname(name, '>'); 929 if (*name != '>') 930 return -1; 931 dstlen = name - dstname; 932 name++; 933 } else { 934 dstname = name; 935 name = getzname(name); 936 dstlen = name - dstname; /* length of DST zone name */ 937 } 938 if (*name != '\0' && *name != ',' && *name != ';') { 939 name = getoffset(name, &dstoffset); 940 if (name == NULL) 941 return -1; 942 } else dstoffset = stdoffset - SECSPERHOUR; 943 if (*name == '\0' && load_result != 0) 944 name = TZDEFRULESTRING; 945 if (*name == ',' || *name == ';') { 946 struct rule start; 947 struct rule end; 948 int year; 949 time_t janfirst; 950 time_t starttime; 951 time_t endtime; 952 953 ++name; 954 if ((name = getrule(name, &start)) == NULL) 955 return -1; 956 if (*name++ != ',') 957 return -1; 958 if ((name = getrule(name, &end)) == NULL) 959 return -1; 960 if (*name != '\0') 961 return -1; 962 sp->typecnt = 2; /* standard time and DST */ 963 /* 964 ** Two transitions per year, from EPOCH_YEAR forward. 965 */ 966 sp->ttis[0].tt_gmtoff = -dstoffset; 967 sp->ttis[0].tt_isdst = 1; 968 sp->ttis[0].tt_abbrind = stdlen + 1; 969 sp->ttis[1].tt_gmtoff = -stdoffset; 970 sp->ttis[1].tt_isdst = 0; 971 sp->ttis[1].tt_abbrind = 0; 972 atp = sp->ats; 973 typep = sp->types; 974 janfirst = 0; 975 sp->timecnt = 0; 976 for (year = EPOCH_YEAR; 977 sp->timecnt + 2 <= TZ_MAX_TIMES; 978 ++year) { 979 time_t newfirst; 980 981 starttime = transtime(janfirst, year, &start, 982 stdoffset); 983 endtime = transtime(janfirst, year, &end, 984 dstoffset); 985 if (starttime > endtime) { 986 *atp++ = endtime; 987 *typep++ = 1; /* DST ends */ 988 *atp++ = starttime; 989 *typep++ = 0; /* DST begins */ 990 } else { 991 *atp++ = starttime; 992 *typep++ = 0; /* DST begins */ 993 *atp++ = endtime; 994 *typep++ = 1; /* DST ends */ 995 } 996 sp->timecnt += 2; 997 newfirst = janfirst; 998 newfirst += year_lengths[isleap(year)] * 999 SECSPERDAY; 1000 if (newfirst <= janfirst) 1001 break; 1002 janfirst = newfirst; 1003 } 1004 } else { 1005 long theirstdoffset; 1006 long theirdstoffset; 1007 long theiroffset; 1008 int isdst; 1009 int i; 1010 int j; 1011 1012 if (*name != '\0') 1013 return -1; 1014 /* 1015 ** Initial values of theirstdoffset and theirdstoffset. 1016 */ 1017 theirstdoffset = 0; 1018 for (i = 0; i < sp->timecnt; ++i) { 1019 j = sp->types[i]; 1020 if (!sp->ttis[j].tt_isdst) { 1021 theirstdoffset = 1022 -sp->ttis[j].tt_gmtoff; 1023 break; 1024 } 1025 } 1026 theirdstoffset = 0; 1027 for (i = 0; i < sp->timecnt; ++i) { 1028 j = sp->types[i]; 1029 if (sp->ttis[j].tt_isdst) { 1030 theirdstoffset = 1031 -sp->ttis[j].tt_gmtoff; 1032 break; 1033 } 1034 } 1035 /* 1036 ** Initially we're assumed to be in standard time. 1037 */ 1038 isdst = FALSE; 1039 theiroffset = theirstdoffset; 1040 /* 1041 ** Now juggle transition times and types 1042 ** tracking offsets as you do. 1043 */ 1044 for (i = 0; i < sp->timecnt; ++i) { 1045 j = sp->types[i]; 1046 sp->types[i] = sp->ttis[j].tt_isdst; 1047 if (sp->ttis[j].tt_ttisgmt) { 1048 /* No adjustment to transition time */ 1049 } else { 1050 /* 1051 ** If summer time is in effect, and the 1052 ** transition time was not specified as 1053 ** standard time, add the summer time 1054 ** offset to the transition time; 1055 ** otherwise, add the standard time 1056 ** offset to the transition time. 1057 */ 1058 /* 1059 ** Transitions from DST to DDST 1060 ** will effectively disappear since 1061 ** POSIX provides for only one DST 1062 ** offset. 1063 */ 1064 if (isdst && !sp->ttis[j].tt_ttisstd) { 1065 sp->ats[i] += dstoffset - 1066 theirdstoffset; 1067 } else { 1068 sp->ats[i] += stdoffset - 1069 theirstdoffset; 1070 } 1071 } 1072 theiroffset = -sp->ttis[j].tt_gmtoff; 1073 if (sp->ttis[j].tt_isdst) 1074 theirdstoffset = theiroffset; 1075 else theirstdoffset = theiroffset; 1076 } 1077 /* 1078 ** Finally, fill in ttis. 1079 ** ttisstd and ttisgmt need not be handled. 1080 */ 1081 sp->ttis[0].tt_gmtoff = -stdoffset; 1082 sp->ttis[0].tt_isdst = FALSE; 1083 sp->ttis[0].tt_abbrind = 0; 1084 sp->ttis[1].tt_gmtoff = -dstoffset; 1085 sp->ttis[1].tt_isdst = TRUE; 1086 sp->ttis[1].tt_abbrind = stdlen + 1; 1087 sp->typecnt = 2; 1088 } 1089 } else { 1090 dstlen = 0; 1091 sp->typecnt = 1; /* only standard time */ 1092 sp->timecnt = 0; 1093 sp->ttis[0].tt_gmtoff = -stdoffset; 1094 sp->ttis[0].tt_isdst = 0; 1095 sp->ttis[0].tt_abbrind = 0; 1096 } 1097 sp->charcnt = stdlen + 1; 1098 if (dstlen != 0) 1099 sp->charcnt += dstlen + 1; 1100 if ((size_t) sp->charcnt > sizeof sp->chars) 1101 return -1; 1102 cp = sp->chars; 1103 strncpy(cp, stdname, stdlen); 1104 cp += stdlen; 1105 *cp++ = '\0'; 1106 if (dstlen != 0) { 1107 strncpy(cp, dstname, dstlen); 1108 *(cp + dstlen) = '\0'; 1109 } 1110 return 0; 1111 } 1112 1113 static void 1114 gmtload(struct state * const sp) 1115 { 1116 if (tzload(gmt, sp, TRUE) != 0) 1117 tzparse(gmt, sp, TRUE); 1118 } 1119 1120 static void 1121 tzsetwall_basic(int rdlocked) 1122 { 1123 if (!rdlocked) 1124 _RWLOCK_RDLOCK(&lcl_rwlock); 1125 if (lcl_is_set < 0) { 1126 if (!rdlocked) 1127 _RWLOCK_UNLOCK(&lcl_rwlock); 1128 return; 1129 } 1130 _RWLOCK_UNLOCK(&lcl_rwlock); 1131 1132 _RWLOCK_WRLOCK(&lcl_rwlock); 1133 lcl_is_set = -1; 1134 1135 if (tzload(NULL, lclptr, TRUE) != 0) 1136 gmtload(lclptr); 1137 settzname(); 1138 _RWLOCK_UNLOCK(&lcl_rwlock); 1139 1140 if (rdlocked) 1141 _RWLOCK_RDLOCK(&lcl_rwlock); 1142 } 1143 1144 void 1145 tzsetwall(void) 1146 { 1147 tzsetwall_basic(0); 1148 } 1149 1150 static void 1151 tzset_basic(int rdlocked) 1152 { 1153 const char * name; 1154 1155 name = getenv("TZ"); 1156 if (name == NULL) { 1157 tzsetwall_basic(rdlocked); 1158 return; 1159 } 1160 1161 if (!rdlocked) 1162 _RWLOCK_RDLOCK(&lcl_rwlock); 1163 if (lcl_is_set > 0 && strcmp(lcl_TZname, name) == 0) { 1164 if (!rdlocked) 1165 _RWLOCK_UNLOCK(&lcl_rwlock); 1166 return; 1167 } 1168 _RWLOCK_UNLOCK(&lcl_rwlock); 1169 1170 _RWLOCK_WRLOCK(&lcl_rwlock); 1171 lcl_is_set = strlen(name) < sizeof lcl_TZname; 1172 if (lcl_is_set) 1173 strcpy(lcl_TZname, name); 1174 1175 if (*name == '\0') { 1176 /* 1177 ** User wants it fast rather than right. 1178 */ 1179 lclptr->leapcnt = 0; /* so, we're off a little */ 1180 lclptr->timecnt = 0; 1181 lclptr->typecnt = 0; 1182 lclptr->ttis[0].tt_isdst = 0; 1183 lclptr->ttis[0].tt_gmtoff = 0; 1184 lclptr->ttis[0].tt_abbrind = 0; 1185 strcpy(lclptr->chars, gmt); 1186 } else if (tzload(name, lclptr, TRUE) != 0) 1187 if (name[0] == ':' || tzparse(name, lclptr, FALSE) != 0) 1188 gmtload(lclptr); 1189 settzname(); 1190 _RWLOCK_UNLOCK(&lcl_rwlock); 1191 1192 if (rdlocked) 1193 _RWLOCK_RDLOCK(&lcl_rwlock); 1194 } 1195 1196 void 1197 tzset(void) 1198 { 1199 tzset_basic(0); 1200 } 1201 1202 /* 1203 ** The easy way to behave "as if no library function calls" localtime 1204 ** is to not call it--so we drop its guts into "localsub", which can be 1205 ** freely called. (And no, the PANS doesn't require the above behavior-- 1206 ** but it *is* desirable.) 1207 ** 1208 ** The unused offset argument is for the benefit of mktime variants. 1209 */ 1210 1211 /*ARGSUSED*/ 1212 static struct tm * 1213 localsub(const time_t * const timep, const long offset __unused, 1214 struct tm * const tmp) 1215 { 1216 struct state * sp; 1217 const struct ttinfo * ttisp; 1218 int i; 1219 struct tm * result; 1220 const time_t t = *timep; 1221 1222 sp = lclptr; 1223 1224 if ((sp->goback && t < sp->ats[0]) || 1225 (sp->goahead && t > sp->ats[sp->timecnt - 1])) { 1226 time_t newt = t; 1227 time_t seconds; 1228 time_t tcycles; 1229 int_fast64_t icycles; 1230 1231 if (t < sp->ats[0]) 1232 seconds = sp->ats[0] - t; 1233 else seconds = t - sp->ats[sp->timecnt - 1]; 1234 --seconds; 1235 tcycles = seconds / YEARSPERREPEAT / AVGSECSPERYEAR; 1236 ++tcycles; 1237 icycles = tcycles; 1238 if (tcycles - icycles >= 1 || icycles - tcycles >= 1) 1239 return NULL; 1240 seconds = icycles; 1241 seconds *= YEARSPERREPEAT; 1242 seconds *= AVGSECSPERYEAR; 1243 if (t < sp->ats[0]) 1244 newt += seconds; 1245 else newt -= seconds; 1246 if (newt < sp->ats[0] || 1247 newt > sp->ats[sp->timecnt - 1]) 1248 return NULL; /* "cannot happen" */ 1249 result = localsub(&newt, offset, tmp); 1250 if (result == tmp) { 1251 time_t newy; 1252 1253 newy = tmp->tm_year; 1254 if (t < sp->ats[0]) 1255 newy -= icycles * YEARSPERREPEAT; 1256 else newy += icycles * YEARSPERREPEAT; 1257 tmp->tm_year = newy; 1258 if (tmp->tm_year != newy) 1259 return NULL; 1260 } 1261 return result; 1262 } 1263 if (sp->timecnt == 0 || t < sp->ats[0]) { 1264 i = 0; 1265 while (sp->ttis[i].tt_isdst) 1266 if (++i >= sp->typecnt) { 1267 i = 0; 1268 break; 1269 } 1270 } else { 1271 int lo = 1; 1272 int hi = sp->timecnt; 1273 1274 while (lo < hi) { 1275 int mid = (lo + hi) >> 1; 1276 1277 if (t < sp->ats[mid]) 1278 hi = mid; 1279 else lo = mid + 1; 1280 } 1281 i = (int) sp->types[lo - 1]; 1282 } 1283 ttisp = &sp->ttis[i]; 1284 /* 1285 ** To get (wrong) behavior that's compatible with System V Release 2.0 1286 ** you'd replace the statement below with 1287 ** t += ttisp->tt_gmtoff; 1288 ** timesub(&t, 0L, sp, tmp); 1289 */ 1290 result = timesub(&t, ttisp->tt_gmtoff, sp, tmp); 1291 tmp->tm_isdst = ttisp->tt_isdst; 1292 tzname[tmp->tm_isdst] = &sp->chars[ttisp->tt_abbrind]; 1293 #ifdef TM_ZONE 1294 tmp->TM_ZONE = &sp->chars[ttisp->tt_abbrind]; 1295 #endif /* defined TM_ZONE */ 1296 return result; 1297 } 1298 1299 struct tm * 1300 localtime_r(const time_t * const timep, struct tm *p_tm) 1301 { 1302 _RWLOCK_RDLOCK(&lcl_rwlock); 1303 tzset_basic(1); 1304 localsub(timep, 0L, p_tm); 1305 _RWLOCK_UNLOCK(&lcl_rwlock); 1306 return(p_tm); 1307 } 1308 1309 struct tm * 1310 localtime(const time_t * const timep) 1311 { 1312 static pthread_mutex_t localtime_mutex = PTHREAD_MUTEX_INITIALIZER; 1313 static pthread_key_t localtime_key = -1; 1314 struct tm *p_tm; 1315 1316 if (__isthreaded != 0) { 1317 if (localtime_key < 0) { 1318 _pthread_mutex_lock(&localtime_mutex); 1319 if (localtime_key < 0) { 1320 if (_pthread_key_create(&localtime_key, free) < 0) { 1321 _pthread_mutex_unlock(&localtime_mutex); 1322 return(NULL); 1323 } 1324 } 1325 _pthread_mutex_unlock(&localtime_mutex); 1326 } 1327 p_tm = _pthread_getspecific(localtime_key); 1328 if (p_tm == NULL) { 1329 if ((p_tm = (struct tm *)malloc(sizeof(struct tm))) 1330 == NULL) 1331 return(NULL); 1332 _pthread_setspecific(localtime_key, p_tm); 1333 } 1334 _RWLOCK_RDLOCK(&lcl_rwlock); 1335 tzset_basic(1); 1336 localsub(timep, 0L, p_tm); 1337 _RWLOCK_UNLOCK(&lcl_rwlock); 1338 return(p_tm); 1339 } else { 1340 tzset_basic(0); 1341 localsub(timep, 0L, &tm); 1342 return(&tm); 1343 } 1344 } 1345 1346 /* 1347 ** gmtsub is to gmtime as localsub is to localtime. 1348 */ 1349 1350 static struct tm * 1351 gmtsub(const time_t * const timep, const long offset, struct tm * const tmp) 1352 { 1353 struct tm * result; 1354 1355 if (!gmt_is_set) { 1356 _MUTEX_LOCK(&gmt_mutex); 1357 if (!gmt_is_set) { 1358 gmtload(gmtptr); 1359 gmt_is_set = TRUE; 1360 } 1361 _MUTEX_UNLOCK(&gmt_mutex); 1362 } 1363 result = timesub(timep, offset, gmtptr, tmp); 1364 #ifdef TM_ZONE 1365 /* 1366 ** Could get fancy here and deliver something such as 1367 ** "UTC+xxxx" or "UTC-xxxx" if offset is non-zero, 1368 ** but this is no time for a treasure hunt. 1369 */ 1370 if (offset != 0) 1371 tmp->TM_ZONE = wildabbr; 1372 else 1373 tmp->TM_ZONE = gmtptr->chars; 1374 #endif /* defined TM_ZONE */ 1375 return result; 1376 } 1377 1378 struct tm * 1379 gmtime(const time_t * const timep) 1380 { 1381 static pthread_mutex_t gmtime_mutex = PTHREAD_MUTEX_INITIALIZER; 1382 static pthread_key_t gmtime_key = -1; 1383 struct tm *p_tm; 1384 1385 if (__isthreaded != 0) { 1386 if (gmtime_key < 0) { 1387 _pthread_mutex_lock(&gmtime_mutex); 1388 if (gmtime_key < 0) { 1389 if (_pthread_key_create(&gmtime_key, free) < 0) { 1390 _pthread_mutex_unlock(&gmtime_mutex); 1391 return(NULL); 1392 } 1393 } 1394 _pthread_mutex_unlock(&gmtime_mutex); 1395 } 1396 /* 1397 * Changed to follow POSIX.1 threads standard, which 1398 * is what BSD currently has. 1399 */ 1400 if ((p_tm = _pthread_getspecific(gmtime_key)) == NULL) { 1401 if ((p_tm = (struct tm *)malloc(sizeof(struct tm))) 1402 == NULL) { 1403 return(NULL); 1404 } 1405 _pthread_setspecific(gmtime_key, p_tm); 1406 } 1407 return gmtsub(timep, 0L, p_tm); 1408 } else { 1409 return gmtsub(timep, 0L, &tm); 1410 } 1411 } 1412 1413 struct tm * 1414 gmtime_r(const time_t * timep, struct tm * tmp) 1415 { 1416 return gmtsub(timep, 0L, tmp); 1417 } 1418 1419 struct tm * 1420 offtime(const time_t * const timep, const long offset) 1421 { 1422 return gmtsub(timep, offset, &tm); 1423 } 1424 1425 /* 1426 ** Return the number of leap years through the end of the given year 1427 ** where, to make the math easy, the answer for year zero is defined as zero. 1428 */ 1429 1430 static int 1431 leaps_thru_end_of(const int y) 1432 { 1433 return (y >= 0) ? (y / 4 - y / 100 + y / 400) : 1434 -(leaps_thru_end_of(-(y + 1)) + 1); 1435 } 1436 1437 static struct tm * 1438 timesub(const time_t * const timep, const long offset, 1439 const struct state * const sp, struct tm * const tmp) 1440 { 1441 const struct lsinfo * lp; 1442 time_t tdays; 1443 int idays; /* unsigned would be so 2003 */ 1444 long rem; 1445 int y; 1446 int yleap; 1447 const int * ip; 1448 long corr; 1449 int hit; 1450 int i; 1451 1452 corr = 0; 1453 hit = 0; 1454 i = sp->leapcnt; 1455 1456 while (--i >= 0) { 1457 lp = &sp->lsis[i]; 1458 if (*timep >= lp->ls_trans) { 1459 if (*timep == lp->ls_trans) { 1460 hit = ((i == 0 && lp->ls_corr > 0) || 1461 lp->ls_corr > sp->lsis[i - 1].ls_corr); 1462 if (hit) 1463 while (i > 0 && 1464 sp->lsis[i].ls_trans == 1465 sp->lsis[i - 1].ls_trans + 1 && 1466 sp->lsis[i].ls_corr == 1467 sp->lsis[i - 1].ls_corr + 1) { 1468 ++hit; 1469 --i; 1470 } 1471 } 1472 corr = lp->ls_corr; 1473 break; 1474 } 1475 } 1476 y = EPOCH_YEAR; 1477 tdays = *timep / SECSPERDAY; 1478 rem = *timep - tdays * SECSPERDAY; 1479 while (tdays < 0 || tdays >= year_lengths[isleap(y)]) { 1480 int newy; 1481 time_t tdelta; 1482 int idelta; 1483 int leapdays; 1484 1485 tdelta = tdays / DAYSPERLYEAR; 1486 idelta = tdelta; 1487 if (tdelta - idelta >= 1 || idelta - tdelta >= 1) 1488 return NULL; 1489 if (idelta == 0) 1490 idelta = (tdays < 0) ? -1 : 1; 1491 newy = y; 1492 if (increment_overflow(&newy, idelta)) 1493 return NULL; 1494 leapdays = leaps_thru_end_of(newy - 1) - 1495 leaps_thru_end_of(y - 1); 1496 tdays -= ((time_t) newy - y) * DAYSPERNYEAR; 1497 tdays -= leapdays; 1498 y = newy; 1499 } 1500 { 1501 long seconds; 1502 1503 seconds = tdays * SECSPERDAY + 0.5; 1504 tdays = seconds / SECSPERDAY; 1505 rem += seconds - tdays * SECSPERDAY; 1506 } 1507 /* 1508 ** Given the range, we can now fearlessly cast... 1509 */ 1510 idays = tdays; 1511 rem += offset - corr; 1512 while (rem < 0) { 1513 rem += SECSPERDAY; 1514 --idays; 1515 } 1516 while (rem >= SECSPERDAY) { 1517 rem -= SECSPERDAY; 1518 ++idays; 1519 } 1520 while (idays < 0) { 1521 if (increment_overflow(&y, -1)) 1522 return NULL; 1523 idays += year_lengths[isleap(y)]; 1524 } 1525 while (idays >= year_lengths[isleap(y)]) { 1526 idays -= year_lengths[isleap(y)]; 1527 if (increment_overflow(&y, 1)) 1528 return NULL; 1529 } 1530 tmp->tm_year = y; 1531 if (increment_overflow(&tmp->tm_year, -TM_YEAR_BASE)) 1532 return NULL; 1533 tmp->tm_yday = idays; 1534 /* 1535 ** The "extra" mods below avoid overflow problems. 1536 */ 1537 tmp->tm_wday = EPOCH_WDAY + 1538 ((y - EPOCH_YEAR) % DAYSPERWEEK) * 1539 (DAYSPERNYEAR % DAYSPERWEEK) + 1540 leaps_thru_end_of(y - 1) - 1541 leaps_thru_end_of(EPOCH_YEAR - 1) + 1542 idays; 1543 tmp->tm_wday %= DAYSPERWEEK; 1544 if (tmp->tm_wday < 0) 1545 tmp->tm_wday += DAYSPERWEEK; 1546 tmp->tm_hour = (int) (rem / SECSPERHOUR); 1547 rem %= SECSPERHOUR; 1548 tmp->tm_min = (int) (rem / SECSPERMIN); 1549 /* 1550 ** A positive leap second requires a special 1551 ** representation. This uses "... ??:59:60" et seq. 1552 */ 1553 tmp->tm_sec = (int) (rem % SECSPERMIN) + hit; 1554 ip = mon_lengths[isleap(y)]; 1555 for (tmp->tm_mon = 0; idays >= ip[tmp->tm_mon]; ++(tmp->tm_mon)) 1556 idays -= ip[tmp->tm_mon]; 1557 tmp->tm_mday = (int) (idays + 1); 1558 tmp->tm_isdst = 0; 1559 #ifdef TM_GMTOFF 1560 tmp->TM_GMTOFF = offset; 1561 #endif /* defined TM_GMTOFF */ 1562 return tmp; 1563 } 1564 1565 char * 1566 ctime(const time_t * const timep) 1567 { 1568 /* 1569 ** Section 4.12.3.2 of X3.159-1989 requires that 1570 ** The ctime function converts the calendar time pointed to by timer 1571 ** to local time in the form of a string. It is equivalent to 1572 ** asctime(localtime(timer)) 1573 */ 1574 return asctime(localtime(timep)); 1575 } 1576 1577 char * 1578 ctime_r(const time_t * const timep, char *buf) 1579 { 1580 struct tm mytm; 1581 return asctime_r(localtime_r(timep, &mytm), buf); 1582 } 1583 1584 /* 1585 ** Adapted from code provided by Robert Elz, who writes: 1586 ** The "best" way to do mktime I think is based on an idea of Bob 1587 ** Kridle's (so its said...) from a long time ago. 1588 ** It does a binary search of the time_t space. Since time_t's are 1589 ** just 32 bits, its a max of 32 iterations (even at 64 bits it 1590 ** would still be very reasonable). 1591 */ 1592 1593 #ifndef WRONG 1594 #define WRONG (-1) 1595 #endif /* !defined WRONG */ 1596 1597 /* 1598 ** Simplified normalize logic courtesy Paul Eggert. 1599 */ 1600 1601 static int 1602 increment_overflow(int *number, int delta) 1603 { 1604 int number0; 1605 1606 number0 = *number; 1607 *number += delta; 1608 return (*number < number0) != (delta < 0); 1609 } 1610 1611 static int 1612 long_increment_overflow(long *number, int delta) 1613 { 1614 long number0; 1615 1616 number0 = *number; 1617 *number += delta; 1618 return (*number < number0) != (delta < 0); 1619 } 1620 1621 static int 1622 normalize_overflow(int * const tensptr, int * const unitsptr, const int base) 1623 { 1624 int tensdelta; 1625 1626 tensdelta = (*unitsptr >= 0) ? 1627 (*unitsptr / base) : 1628 (-1 - (-1 - *unitsptr) / base); 1629 *unitsptr -= tensdelta * base; 1630 return increment_overflow(tensptr, tensdelta); 1631 } 1632 1633 static int 1634 long_normalize_overflow(long * const tensptr, int * const unitsptr, 1635 const int base) 1636 { 1637 int tensdelta; 1638 1639 tensdelta = (*unitsptr >= 0) ? 1640 (*unitsptr / base) : 1641 (-1 - (-1 - *unitsptr) / base); 1642 *unitsptr -= tensdelta * base; 1643 return long_increment_overflow(tensptr, tensdelta); 1644 } 1645 1646 static int 1647 tmcomp(const struct tm * const atmp, const struct tm * const btmp) 1648 { 1649 int result; 1650 1651 if ((result = (atmp->tm_year - btmp->tm_year)) == 0 && 1652 (result = (atmp->tm_mon - btmp->tm_mon)) == 0 && 1653 (result = (atmp->tm_mday - btmp->tm_mday)) == 0 && 1654 (result = (atmp->tm_hour - btmp->tm_hour)) == 0 && 1655 (result = (atmp->tm_min - btmp->tm_min)) == 0) 1656 result = atmp->tm_sec - btmp->tm_sec; 1657 return result; 1658 } 1659 1660 static time_t 1661 time2sub(struct tm * const tmp, 1662 struct tm * (* const funcp)(const time_t *, long, struct tm *), 1663 const long offset, int * const okayp, const int do_norm_secs) 1664 { 1665 const struct state * sp; 1666 int dir; 1667 int i, j; 1668 int saved_seconds; 1669 long li; 1670 time_t lo; 1671 time_t hi; 1672 long y; 1673 time_t newt; 1674 time_t t; 1675 struct tm yourtm, mytm; 1676 1677 *okayp = FALSE; 1678 yourtm = *tmp; 1679 if (do_norm_secs) { 1680 if (normalize_overflow(&yourtm.tm_min, &yourtm.tm_sec, 1681 SECSPERMIN)) 1682 return WRONG; 1683 } 1684 if (normalize_overflow(&yourtm.tm_hour, &yourtm.tm_min, MINSPERHOUR)) 1685 return WRONG; 1686 if (normalize_overflow(&yourtm.tm_mday, &yourtm.tm_hour, HOURSPERDAY)) 1687 return WRONG; 1688 y = yourtm.tm_year; 1689 if (long_normalize_overflow(&y, &yourtm.tm_mon, MONSPERYEAR)) 1690 return WRONG; 1691 /* 1692 ** Turn y into an actual year number for now. 1693 ** It is converted back to an offset from TM_YEAR_BASE later. 1694 */ 1695 if (long_increment_overflow(&y, TM_YEAR_BASE)) 1696 return WRONG; 1697 while (yourtm.tm_mday <= 0) { 1698 if (long_increment_overflow(&y, -1)) 1699 return WRONG; 1700 li = y + (1 < yourtm.tm_mon); 1701 yourtm.tm_mday += year_lengths[isleap(li)]; 1702 } 1703 while (yourtm.tm_mday > DAYSPERLYEAR) { 1704 li = y + (1 < yourtm.tm_mon); 1705 yourtm.tm_mday -= year_lengths[isleap(li)]; 1706 if (long_increment_overflow(&y, 1)) 1707 return WRONG; 1708 } 1709 for ( ; ; ) { 1710 i = mon_lengths[isleap(y)][yourtm.tm_mon]; 1711 if (yourtm.tm_mday <= i) 1712 break; 1713 yourtm.tm_mday -= i; 1714 if (++yourtm.tm_mon >= MONSPERYEAR) { 1715 yourtm.tm_mon = 0; 1716 if (long_increment_overflow(&y, 1)) 1717 return WRONG; 1718 } 1719 } 1720 if (long_increment_overflow(&y, -TM_YEAR_BASE)) 1721 return WRONG; 1722 yourtm.tm_year = y; 1723 if (yourtm.tm_year != y) 1724 return WRONG; 1725 if (yourtm.tm_sec >= 0 && yourtm.tm_sec < SECSPERMIN) 1726 saved_seconds = 0; 1727 else if (y + TM_YEAR_BASE < EPOCH_YEAR) { 1728 /* 1729 ** We can't set tm_sec to 0, because that might push the 1730 ** time below the minimum representable time. 1731 ** Set tm_sec to 59 instead. 1732 ** This assumes that the minimum representable time is 1733 ** not in the same minute that a leap second was deleted from, 1734 ** which is a safer assumption than using 58 would be. 1735 */ 1736 if (increment_overflow(&yourtm.tm_sec, 1 - SECSPERMIN)) 1737 return WRONG; 1738 saved_seconds = yourtm.tm_sec; 1739 yourtm.tm_sec = SECSPERMIN - 1; 1740 } else { 1741 saved_seconds = yourtm.tm_sec; 1742 yourtm.tm_sec = 0; 1743 } 1744 /* 1745 ** Do a binary search (this works whatever time_t's type is). 1746 */ 1747 if (!TYPE_SIGNED(time_t)) { 1748 lo = 0; 1749 hi = lo - 1; 1750 } else if (!TYPE_INTEGRAL(time_t)) { 1751 if (sizeof(time_t) > sizeof(float)) 1752 hi = (time_t) DBL_MAX; 1753 else hi = (time_t) FLT_MAX; 1754 lo = -hi; 1755 } else { 1756 lo = 1; 1757 for (i = 0; i < (int) TYPE_BIT(time_t) - 1; ++i) 1758 lo *= 2; 1759 hi = -(lo + 1); 1760 } 1761 for ( ; ; ) { 1762 t = lo / 2 + hi / 2; 1763 if (t < lo) 1764 t = lo; 1765 else if (t > hi) 1766 t = hi; 1767 if ((*funcp)(&t, offset, &mytm) == NULL) { 1768 /* 1769 ** Assume that t is too extreme to be represented in 1770 ** a struct tm; arrange things so that it is less 1771 ** extreme on the next pass. 1772 */ 1773 dir = (t > 0) ? 1 : -1; 1774 } else dir = tmcomp(&mytm, &yourtm); 1775 if (dir != 0) { 1776 if (t == lo) { 1777 ++t; 1778 if (t <= lo) 1779 return WRONG; 1780 ++lo; 1781 } else if (t == hi) { 1782 --t; 1783 if (t >= hi) 1784 return WRONG; 1785 --hi; 1786 } 1787 if (lo > hi) 1788 return WRONG; 1789 if (dir > 0) 1790 hi = t; 1791 else lo = t; 1792 continue; 1793 } 1794 if (yourtm.tm_isdst < 0 || mytm.tm_isdst == yourtm.tm_isdst) 1795 break; 1796 /* 1797 ** Right time, wrong type. 1798 ** Hunt for right time, right type. 1799 ** It's okay to guess wrong since the guess 1800 ** gets checked. 1801 */ 1802 sp = (const struct state *) 1803 ((funcp == localsub) ? lclptr : gmtptr); 1804 1805 for (i = sp->typecnt - 1; i >= 0; --i) { 1806 if (sp->ttis[i].tt_isdst != yourtm.tm_isdst) 1807 continue; 1808 for (j = sp->typecnt - 1; j >= 0; --j) { 1809 if (sp->ttis[j].tt_isdst == yourtm.tm_isdst) 1810 continue; 1811 newt = t + sp->ttis[j].tt_gmtoff - 1812 sp->ttis[i].tt_gmtoff; 1813 if ((*funcp)(&newt, offset, &mytm) == NULL) 1814 continue; 1815 if (tmcomp(&mytm, &yourtm) != 0) 1816 continue; 1817 if (mytm.tm_isdst != yourtm.tm_isdst) 1818 continue; 1819 /* 1820 ** We have a match. 1821 */ 1822 t = newt; 1823 goto label; 1824 } 1825 } 1826 return WRONG; 1827 } 1828 label: 1829 newt = t + saved_seconds; 1830 if ((newt < t) != (saved_seconds < 0)) 1831 return WRONG; 1832 t = newt; 1833 if ((*funcp)(&t, offset, tmp)) 1834 *okayp = TRUE; 1835 return t; 1836 } 1837 1838 static time_t 1839 time2(struct tm * const tmp, 1840 struct tm * (* const funcp)(const time_t *, long, struct tm *), 1841 const long offset, int * const okayp) 1842 { 1843 time_t t; 1844 1845 /* 1846 ** First try without normalization of seconds 1847 ** (in case tm_sec contains a value associated with a leap second). 1848 ** If that fails, try with normalization of seconds. 1849 */ 1850 t = time2sub(tmp, funcp, offset, okayp, FALSE); 1851 return *okayp ? t : time2sub(tmp, funcp, offset, okayp, TRUE); 1852 } 1853 1854 static time_t 1855 time1(struct tm * const tmp, 1856 struct tm * (* const funcp)(const time_t *, long, struct tm *), 1857 const long offset) 1858 { 1859 time_t t; 1860 const struct state * sp; 1861 int samei, otheri; 1862 int sameind, otherind; 1863 int i; 1864 int nseen; 1865 int seen[TZ_MAX_TYPES]; 1866 int types[TZ_MAX_TYPES]; 1867 int okay; 1868 1869 if (tmp == NULL) { 1870 errno = EINVAL; 1871 return WRONG; 1872 } 1873 if (tmp->tm_isdst > 1) 1874 tmp->tm_isdst = 1; 1875 t = time2(tmp, funcp, offset, &okay); 1876 1877 /* 1878 ** PCTS code courtesy Grant Sullivan. 1879 */ 1880 if (okay) 1881 return t; 1882 if (tmp->tm_isdst < 0) 1883 tmp->tm_isdst = 0; /* reset to std and try again */ 1884 1885 /* 1886 ** We're supposed to assume that somebody took a time of one type 1887 ** and did some math on it that yielded a "struct tm" that's bad. 1888 ** We try to divine the type they started from and adjust to the 1889 ** type they need. 1890 */ 1891 sp = (const struct state *) ((funcp == localsub) ? lclptr : gmtptr); 1892 1893 for (i = 0; i < sp->typecnt; ++i) 1894 seen[i] = FALSE; 1895 nseen = 0; 1896 for (i = sp->timecnt - 1; i >= 0; --i) 1897 if (!seen[sp->types[i]]) { 1898 seen[sp->types[i]] = TRUE; 1899 types[nseen++] = sp->types[i]; 1900 } 1901 for (sameind = 0; sameind < nseen; ++sameind) { 1902 samei = types[sameind]; 1903 if (sp->ttis[samei].tt_isdst != tmp->tm_isdst) 1904 continue; 1905 for (otherind = 0; otherind < nseen; ++otherind) { 1906 otheri = types[otherind]; 1907 if (sp->ttis[otheri].tt_isdst == tmp->tm_isdst) 1908 continue; 1909 tmp->tm_sec += sp->ttis[otheri].tt_gmtoff - 1910 sp->ttis[samei].tt_gmtoff; 1911 tmp->tm_isdst = !tmp->tm_isdst; 1912 t = time2(tmp, funcp, offset, &okay); 1913 if (okay) 1914 return t; 1915 tmp->tm_sec -= sp->ttis[otheri].tt_gmtoff - 1916 sp->ttis[samei].tt_gmtoff; 1917 tmp->tm_isdst = !tmp->tm_isdst; 1918 } 1919 } 1920 return WRONG; 1921 } 1922 1923 time_t 1924 mktime(struct tm * const tmp) 1925 { 1926 time_t mktime_return_value; 1927 _RWLOCK_RDLOCK(&lcl_rwlock); 1928 tzset_basic(1); 1929 mktime_return_value = time1(tmp, localsub, 0L); 1930 _RWLOCK_UNLOCK(&lcl_rwlock); 1931 return(mktime_return_value); 1932 } 1933 1934 time_t 1935 timelocal(struct tm * const tmp) 1936 { 1937 if (tmp != NULL) 1938 tmp->tm_isdst = -1; /* in case it wasn't initialized */ 1939 return mktime(tmp); 1940 } 1941 1942 time_t 1943 timegm(struct tm * const tmp) 1944 { 1945 if (tmp != NULL) 1946 tmp->tm_isdst = 0; 1947 return time1(tmp, gmtsub, 0L); 1948 } 1949 1950 time_t 1951 timeoff(struct tm * const tmp, const long offset) 1952 { 1953 if (tmp != NULL) 1954 tmp->tm_isdst = 0; 1955 return time1(tmp, gmtsub, offset); 1956 } 1957 1958 #ifdef CMUCS 1959 1960 /* 1961 ** The following is supplied for compatibility with 1962 ** previous versions of the CMUCS runtime library. 1963 */ 1964 1965 long 1966 gtime(struct tm * const tmp) 1967 { 1968 const time_t t = mktime(tmp); 1969 1970 if (t == WRONG) 1971 return -1; 1972 return t; 1973 } 1974 1975 #endif /* defined CMUCS */ 1976 1977 /* 1978 ** XXX--is the below the right way to conditionalize?? 1979 */ 1980 1981 /* 1982 ** IEEE Std 1003.1-1988 (POSIX) legislates that 536457599 1983 ** shall correspond to "Wed Dec 31 23:59:59 UTC 1986", which 1984 ** is not the case if we are accounting for leap seconds. 1985 ** So, we provide the following conversion routines for use 1986 ** when exchanging timestamps with POSIX conforming systems. 1987 */ 1988 1989 static long 1990 leapcorr(time_t *timep) 1991 { 1992 struct state * sp; 1993 struct lsinfo * lp; 1994 int i; 1995 1996 sp = lclptr; 1997 i = sp->leapcnt; 1998 while (--i >= 0) { 1999 lp = &sp->lsis[i]; 2000 if (*timep >= lp->ls_trans) 2001 return lp->ls_corr; 2002 } 2003 return 0; 2004 } 2005 2006 time_t 2007 time2posix(time_t t) 2008 { 2009 tzset(); 2010 return t - leapcorr(&t); 2011 } 2012 2013 time_t 2014 posix2time(time_t t) 2015 { 2016 time_t x; 2017 time_t y; 2018 2019 tzset(); 2020 /* 2021 ** For a positive leap second hit, the result 2022 ** is not unique. For a negative leap second 2023 ** hit, the corresponding time doesn't exist, 2024 ** so we return an adjacent second. 2025 */ 2026 x = t + leapcorr(&t); 2027 y = x - leapcorr(&x); 2028 if (y < t) { 2029 do { 2030 x++; 2031 y = x - leapcorr(&x); 2032 } while (y < t); 2033 if (t != y) 2034 return x - 1; 2035 } else if (y > t) { 2036 do { 2037 --x; 2038 y = x - leapcorr(&x); 2039 } while (y > t); 2040 if (t != y) 2041 return x + 1; 2042 } 2043 return x; 2044 } 2045