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 8.15 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 /* 267 ** And to get the latest zone names into tzname. . . 268 */ 269 for (i = 0; i < sp->timecnt; ++i) { 270 const struct ttinfo * const ttisp = 271 &sp->ttis[ 272 sp->types[i]]; 273 274 tzname[ttisp->tt_isdst] = 275 &sp->chars[ttisp->tt_abbrind]; 276 if (ttisp->tt_isdst) 277 daylight = 1; 278 if (!ttisp->tt_isdst) 279 timezone = -(ttisp->tt_gmtoff); 280 } 281 /* 282 ** Finally, scrub the abbreviations. 283 ** First, replace bogus characters. 284 */ 285 for (i = 0; i < sp->charcnt; ++i) 286 if (strchr(TZ_ABBR_CHAR_SET, sp->chars[i]) == NULL) 287 sp->chars[i] = TZ_ABBR_ERR_CHAR; 288 /* 289 ** Second, truncate long abbreviations. 290 */ 291 for (i = 0; i < sp->typecnt; ++i) { 292 const struct ttinfo * const ttisp = &sp->ttis[i]; 293 char * cp = &sp->chars[ttisp->tt_abbrind]; 294 295 if (strlen(cp) > TZ_ABBR_MAX_LEN && 296 strcmp(cp, GRANDPARENTED) != 0) 297 *(cp + TZ_ABBR_MAX_LEN) = '\0'; 298 } 299 } 300 301 static int 302 differ_by_repeat(const time_t t1, const time_t t0) 303 { 304 int_fast64_t _t0 = t0; 305 int_fast64_t _t1 = t1; 306 307 if (TYPE_INTEGRAL(time_t) && 308 TYPE_BIT(time_t) - TYPE_SIGNED(time_t) < SECSPERREPEAT_BITS) 309 return 0; 310 return _t1 - _t0 == SECSPERREPEAT; 311 } 312 313 static int 314 tzload(const char *name, struct state * const sp, const int doextend) 315 { 316 const char * p; 317 int i; 318 int fid; 319 int stored; 320 int nread; 321 union { 322 struct tzhead tzhead; 323 char buf[2 * sizeof(struct tzhead) + 324 2 * sizeof *sp + 325 4 * TZ_MAX_TIMES]; 326 } u; 327 328 sp->goback = sp->goahead = FALSE; 329 330 /* XXX The following is from OpenBSD, and I'm not sure it is correct */ 331 if (name != NULL && issetugid() != 0) 332 if ((name[0] == ':' && name[1] == '/') || 333 name[0] == '/' || strchr(name, '.')) 334 name = NULL; 335 if (name == NULL && (name = TZDEFAULT) == NULL) 336 return -1; 337 { 338 int doaccess; 339 struct stat stab; 340 /* 341 ** Section 4.9.1 of the C standard says that 342 ** "FILENAME_MAX expands to an integral constant expression 343 ** that is the size needed for an array of char large enough 344 ** to hold the longest file name string that the implementation 345 ** guarantees can be opened." 346 */ 347 char fullname[FILENAME_MAX + 1]; 348 349 if (name[0] == ':') 350 ++name; 351 doaccess = name[0] == '/'; 352 if (!doaccess) { 353 if ((p = TZDIR) == NULL) 354 return -1; 355 if ((strlen(p) + 1 + strlen(name) + 1) >= sizeof fullname) 356 return -1; 357 strcpy(fullname, p); 358 strcat(fullname, "/"); 359 strcat(fullname, name); 360 /* 361 ** Set doaccess if '.' (as in "../") shows up in name. 362 */ 363 if (strchr(name, '.') != NULL) 364 doaccess = TRUE; 365 name = fullname; 366 } 367 if (doaccess && access(name, R_OK) != 0) 368 return -1; 369 if ((fid = _open(name, O_RDONLY)) == -1) 370 return -1; 371 if ((_fstat(fid, &stab) < 0) || !S_ISREG(stab.st_mode)) { 372 _close(fid); 373 return -1; 374 } 375 } 376 nread = _read(fid, u.buf, sizeof u.buf); 377 if (_close(fid) < 0 || nread <= 0) 378 return -1; 379 for (stored = 4; stored <= 8; stored *= 2) { 380 int ttisstdcnt; 381 int ttisgmtcnt; 382 383 ttisstdcnt = (int) detzcode(u.tzhead.tzh_ttisstdcnt); 384 ttisgmtcnt = (int) detzcode(u.tzhead.tzh_ttisgmtcnt); 385 sp->leapcnt = (int) detzcode(u.tzhead.tzh_leapcnt); 386 sp->timecnt = (int) detzcode(u.tzhead.tzh_timecnt); 387 sp->typecnt = (int) detzcode(u.tzhead.tzh_typecnt); 388 sp->charcnt = (int) detzcode(u.tzhead.tzh_charcnt); 389 p = u.tzhead.tzh_charcnt + sizeof u.tzhead.tzh_charcnt; 390 if (sp->leapcnt < 0 || sp->leapcnt > TZ_MAX_LEAPS || 391 sp->typecnt <= 0 || sp->typecnt > TZ_MAX_TYPES || 392 sp->timecnt < 0 || sp->timecnt > TZ_MAX_TIMES || 393 sp->charcnt < 0 || sp->charcnt > TZ_MAX_CHARS || 394 (ttisstdcnt != sp->typecnt && ttisstdcnt != 0) || 395 (ttisgmtcnt != sp->typecnt && ttisgmtcnt != 0)) 396 return -1; 397 if (nread - (p - u.buf) < 398 sp->timecnt * stored + /* ats */ 399 sp->timecnt + /* types */ 400 sp->typecnt * 6 + /* ttinfos */ 401 sp->charcnt + /* chars */ 402 sp->leapcnt * (stored + 4) + /* lsinfos */ 403 ttisstdcnt + /* ttisstds */ 404 ttisgmtcnt) /* ttisgmts */ 405 return -1; 406 for (i = 0; i < sp->timecnt; ++i) { 407 sp->ats[i] = (stored == 4) ? 408 detzcode(p) : detzcode64(p); 409 p += stored; 410 } 411 for (i = 0; i < sp->timecnt; ++i) { 412 sp->types[i] = (unsigned char) *p++; 413 if (sp->types[i] >= sp->typecnt) 414 return -1; 415 } 416 for (i = 0; i < sp->typecnt; ++i) { 417 struct ttinfo * ttisp; 418 419 ttisp = &sp->ttis[i]; 420 ttisp->tt_gmtoff = detzcode(p); 421 p += 4; 422 ttisp->tt_isdst = (unsigned char) *p++; 423 if (ttisp->tt_isdst != 0 && ttisp->tt_isdst != 1) 424 return -1; 425 ttisp->tt_abbrind = (unsigned char) *p++; 426 if (ttisp->tt_abbrind < 0 || 427 ttisp->tt_abbrind > sp->charcnt) 428 return -1; 429 } 430 for (i = 0; i < sp->charcnt; ++i) 431 sp->chars[i] = *p++; 432 sp->chars[i] = '\0'; /* ensure '\0' at end */ 433 for (i = 0; i < sp->leapcnt; ++i) { 434 struct lsinfo * lsisp; 435 436 lsisp = &sp->lsis[i]; 437 lsisp->ls_trans = (stored == 4) ? 438 detzcode(p) : detzcode64(p); 439 p += stored; 440 lsisp->ls_corr = detzcode(p); 441 p += 4; 442 } 443 for (i = 0; i < sp->typecnt; ++i) { 444 struct ttinfo * ttisp; 445 446 ttisp = &sp->ttis[i]; 447 if (ttisstdcnt == 0) 448 ttisp->tt_ttisstd = FALSE; 449 else { 450 ttisp->tt_ttisstd = *p++; 451 if (ttisp->tt_ttisstd != TRUE && 452 ttisp->tt_ttisstd != FALSE) 453 return -1; 454 } 455 } 456 for (i = 0; i < sp->typecnt; ++i) { 457 struct ttinfo * ttisp; 458 459 ttisp = &sp->ttis[i]; 460 if (ttisgmtcnt == 0) 461 ttisp->tt_ttisgmt = FALSE; 462 else { 463 ttisp->tt_ttisgmt = *p++; 464 if (ttisp->tt_ttisgmt != TRUE && 465 ttisp->tt_ttisgmt != FALSE) 466 return -1; 467 } 468 } 469 /* 470 ** Out-of-sort ats should mean we're running on a 471 ** signed time_t system but using a data file with 472 ** unsigned values (or vice versa). 473 */ 474 for (i = 0; i < sp->timecnt - 2; ++i) 475 if (sp->ats[i] > sp->ats[i + 1]) { 476 ++i; 477 if (TYPE_SIGNED(time_t)) { 478 /* 479 ** Ignore the end (easy). 480 */ 481 sp->timecnt = i; 482 } else { 483 /* 484 ** Ignore the beginning (harder). 485 */ 486 int j; 487 488 for (j = 0; j + i < sp->timecnt; ++j) { 489 sp->ats[j] = sp->ats[j + i]; 490 sp->types[j] = sp->types[j + i]; 491 } 492 sp->timecnt = j; 493 } 494 break; 495 } 496 /* 497 ** If this is an old file, we're done. 498 */ 499 if (u.tzhead.tzh_version[0] == '\0') 500 break; 501 nread -= p - u.buf; 502 for (i = 0; i < nread; ++i) 503 u.buf[i] = p[i]; 504 /* 505 ** If this is a narrow integer time_t system, we're done. 506 */ 507 if (stored >= (int) sizeof(time_t) && TYPE_INTEGRAL(time_t)) 508 break; 509 } 510 if (doextend && nread > 2 && 511 u.buf[0] == '\n' && u.buf[nread - 1] == '\n' && 512 sp->typecnt + 2 <= TZ_MAX_TYPES) { 513 struct state ts; 514 int result; 515 516 u.buf[nread - 1] = '\0'; 517 result = tzparse(&u.buf[1], &ts, FALSE); 518 if (result == 0 && ts.typecnt == 2 && 519 sp->charcnt + ts.charcnt <= TZ_MAX_CHARS) { 520 for (i = 0; i < 2; ++i) 521 ts.ttis[i].tt_abbrind += 522 sp->charcnt; 523 for (i = 0; i < ts.charcnt; ++i) 524 sp->chars[sp->charcnt++] = 525 ts.chars[i]; 526 i = 0; 527 while (i < ts.timecnt && 528 ts.ats[i] <= 529 sp->ats[sp->timecnt - 1]) 530 ++i; 531 while (i < ts.timecnt && 532 sp->timecnt < TZ_MAX_TIMES) { 533 sp->ats[sp->timecnt] = 534 ts.ats[i]; 535 sp->types[sp->timecnt] = 536 sp->typecnt + 537 ts.types[i]; 538 ++sp->timecnt; 539 ++i; 540 } 541 sp->ttis[sp->typecnt++] = ts.ttis[0]; 542 sp->ttis[sp->typecnt++] = ts.ttis[1]; 543 } 544 } 545 if (sp->timecnt > 1) { 546 for (i = 1; i < sp->timecnt; ++i) 547 if (typesequiv(sp, sp->types[i], sp->types[0]) && 548 differ_by_repeat(sp->ats[i], sp->ats[0])) { 549 sp->goback = TRUE; 550 break; 551 } 552 for (i = sp->timecnt - 2; i >= 0; --i) 553 if (typesequiv(sp, sp->types[sp->timecnt - 1], 554 sp->types[i]) && 555 differ_by_repeat(sp->ats[sp->timecnt - 1], 556 sp->ats[i])) { 557 sp->goahead = TRUE; 558 break; 559 } 560 } 561 return 0; 562 } 563 564 static int 565 typesequiv(const struct state * const sp, const int a, const int b) 566 { 567 int result; 568 569 if (sp == NULL || 570 a < 0 || a >= sp->typecnt || 571 b < 0 || b >= sp->typecnt) 572 result = FALSE; 573 else { 574 const struct ttinfo * ap = &sp->ttis[a]; 575 const struct ttinfo * bp = &sp->ttis[b]; 576 result = ap->tt_gmtoff == bp->tt_gmtoff && 577 ap->tt_isdst == bp->tt_isdst && 578 ap->tt_ttisstd == bp->tt_ttisstd && 579 ap->tt_ttisgmt == bp->tt_ttisgmt && 580 strcmp(&sp->chars[ap->tt_abbrind], 581 &sp->chars[bp->tt_abbrind]) == 0; 582 } 583 return result; 584 } 585 586 static const int mon_lengths[2][MONSPERYEAR] = { 587 { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }, 588 { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 } 589 }; 590 591 static const int year_lengths[2] = { 592 DAYSPERNYEAR, DAYSPERLYEAR 593 }; 594 595 /* 596 ** Given a pointer into a time zone string, scan until a character that is not 597 ** a valid character in a zone name is found. Return a pointer to that 598 ** character. 599 */ 600 601 static const char * 602 getzname(const char *strp) 603 { 604 char c; 605 606 while ((c = *strp) != '\0' && !is_digit(c) && c != ',' && c != '-' && 607 c != '+') 608 ++strp; 609 return strp; 610 } 611 612 /* 613 ** Given a pointer into an extended time zone string, scan until the ending 614 ** delimiter of the zone name is located. Return a pointer to the delimiter. 615 ** 616 ** As with getzname above, the legal character set is actually quite 617 ** restricted, with other characters producing undefined results. 618 ** We don't do any checking here; checking is done later in common-case code. 619 */ 620 621 static const char * 622 getqzname(const char *strp, const int delim) 623 { 624 int c; 625 626 while ((c = *strp) != '\0' && c != delim) 627 ++strp; 628 return strp; 629 } 630 631 /* 632 ** Given a pointer into a time zone string, extract a number from that string. 633 ** Check that the number is within a specified range; if it is not, return 634 ** NULL. 635 ** Otherwise, return a pointer to the first character not part of the number. 636 */ 637 638 static const char * 639 getnum(const char *strp, int * const nump, const int min, const int max) 640 { 641 char c; 642 int num; 643 644 if (strp == NULL || !is_digit(c = *strp)) 645 return NULL; 646 num = 0; 647 do { 648 num = num * 10 + (c - '0'); 649 if (num > max) 650 return NULL; /* illegal value */ 651 c = *++strp; 652 } while (is_digit(c)); 653 if (num < min) 654 return NULL; /* illegal value */ 655 *nump = num; 656 return strp; 657 } 658 659 /* 660 ** Given a pointer into a time zone string, extract a number of seconds, 661 ** in hh[:mm[:ss]] form, from the string. 662 ** If any error occurs, return NULL. 663 ** Otherwise, return a pointer to the first character not part of the number 664 ** of seconds. 665 */ 666 667 static const char * 668 getsecs(const char *strp, long * const secsp) 669 { 670 int num; 671 672 /* 673 ** `HOURSPERDAY * DAYSPERWEEK - 1' allows quasi-Posix rules like 674 ** "M10.4.6/26", which does not conform to Posix, 675 ** but which specifies the equivalent of 676 ** ``02:00 on the first Sunday on or after 23 Oct''. 677 */ 678 strp = getnum(strp, &num, 0, HOURSPERDAY * DAYSPERWEEK - 1); 679 if (strp == NULL) 680 return NULL; 681 *secsp = num * (long) SECSPERHOUR; 682 if (*strp == ':') { 683 ++strp; 684 strp = getnum(strp, &num, 0, MINSPERHOUR - 1); 685 if (strp == NULL) 686 return NULL; 687 *secsp += num * SECSPERMIN; 688 if (*strp == ':') { 689 ++strp; 690 /* `SECSPERMIN' allows for leap seconds. */ 691 strp = getnum(strp, &num, 0, SECSPERMIN); 692 if (strp == NULL) 693 return NULL; 694 *secsp += num; 695 } 696 } 697 return strp; 698 } 699 700 /* 701 ** Given a pointer into a time zone string, extract an offset, in 702 ** [+-]hh[:mm[:ss]] form, from the string. 703 ** If any error occurs, return NULL. 704 ** Otherwise, return a pointer to the first character not part of the time. 705 */ 706 707 static const char * 708 getoffset(const char *strp, long * const offsetp) 709 { 710 int neg = 0; 711 712 if (*strp == '-') { 713 neg = 1; 714 ++strp; 715 } else if (*strp == '+') 716 ++strp; 717 strp = getsecs(strp, offsetp); 718 if (strp == NULL) 719 return NULL; /* illegal time */ 720 if (neg) 721 *offsetp = -*offsetp; 722 return strp; 723 } 724 725 /* 726 ** Given a pointer into a time zone string, extract a rule in the form 727 ** date[/time]. See POSIX section 8 for the format of "date" and "time". 728 ** If a valid rule is not found, return NULL. 729 ** Otherwise, return a pointer to the first character not part of the rule. 730 */ 731 732 static const char * 733 getrule(const char *strp, struct rule * const rulep) 734 { 735 if (*strp == 'J') { 736 /* 737 ** Julian day. 738 */ 739 rulep->r_type = JULIAN_DAY; 740 ++strp; 741 strp = getnum(strp, &rulep->r_day, 1, DAYSPERNYEAR); 742 } else if (*strp == 'M') { 743 /* 744 ** Month, week, day. 745 */ 746 rulep->r_type = MONTH_NTH_DAY_OF_WEEK; 747 ++strp; 748 strp = getnum(strp, &rulep->r_mon, 1, MONSPERYEAR); 749 if (strp == NULL) 750 return NULL; 751 if (*strp++ != '.') 752 return NULL; 753 strp = getnum(strp, &rulep->r_week, 1, 5); 754 if (strp == NULL) 755 return NULL; 756 if (*strp++ != '.') 757 return NULL; 758 strp = getnum(strp, &rulep->r_day, 0, DAYSPERWEEK - 1); 759 } else if (is_digit(*strp)) { 760 /* 761 ** Day of year. 762 */ 763 rulep->r_type = DAY_OF_YEAR; 764 strp = getnum(strp, &rulep->r_day, 0, DAYSPERLYEAR - 1); 765 } else return NULL; /* invalid format */ 766 if (strp == NULL) 767 return NULL; 768 if (*strp == '/') { 769 /* 770 ** Time specified. 771 */ 772 ++strp; 773 strp = getsecs(strp, &rulep->r_time); 774 } else rulep->r_time = 2 * SECSPERHOUR; /* default = 2:00:00 */ 775 return strp; 776 } 777 778 /* 779 ** Given the Epoch-relative time of January 1, 00:00:00 UTC, in a year, the 780 ** year, a rule, and the offset from UTC at the time that rule takes effect, 781 ** calculate the Epoch-relative time that rule takes effect. 782 */ 783 784 static time_t 785 transtime(const time_t janfirst, const int year, 786 const struct rule * const rulep, const long offset) 787 { 788 int leapyear; 789 time_t value; 790 int i; 791 int d, m1, yy0, yy1, yy2, dow; 792 793 INITIALIZE(value); 794 leapyear = isleap(year); 795 switch (rulep->r_type) { 796 797 case JULIAN_DAY: 798 /* 799 ** Jn - Julian day, 1 == January 1, 60 == March 1 even in leap 800 ** years. 801 ** In non-leap years, or if the day number is 59 or less, just 802 ** add SECSPERDAY times the day number-1 to the time of 803 ** January 1, midnight, to get the day. 804 */ 805 value = janfirst + (rulep->r_day - 1) * SECSPERDAY; 806 if (leapyear && rulep->r_day >= 60) 807 value += SECSPERDAY; 808 break; 809 810 case DAY_OF_YEAR: 811 /* 812 ** n - day of year. 813 ** Just add SECSPERDAY times the day number to the time of 814 ** January 1, midnight, to get the day. 815 */ 816 value = janfirst + rulep->r_day * SECSPERDAY; 817 break; 818 819 case MONTH_NTH_DAY_OF_WEEK: 820 /* 821 ** Mm.n.d - nth "dth day" of month m. 822 */ 823 value = janfirst; 824 for (i = 0; i < rulep->r_mon - 1; ++i) 825 value += mon_lengths[leapyear][i] * SECSPERDAY; 826 827 /* 828 ** Use Zeller's Congruence to get day-of-week of first day of 829 ** month. 830 */ 831 m1 = (rulep->r_mon + 9) % 12 + 1; 832 yy0 = (rulep->r_mon <= 2) ? (year - 1) : year; 833 yy1 = yy0 / 100; 834 yy2 = yy0 % 100; 835 dow = ((26 * m1 - 2) / 10 + 836 1 + yy2 + yy2 / 4 + yy1 / 4 - 2 * yy1) % 7; 837 if (dow < 0) 838 dow += DAYSPERWEEK; 839 840 /* 841 ** "dow" is the day-of-week of the first day of the month. Get 842 ** the day-of-month (zero-origin) of the first "dow" day of the 843 ** month. 844 */ 845 d = rulep->r_day - dow; 846 if (d < 0) 847 d += DAYSPERWEEK; 848 for (i = 1; i < rulep->r_week; ++i) { 849 if (d + DAYSPERWEEK >= 850 mon_lengths[leapyear][rulep->r_mon - 1]) 851 break; 852 d += DAYSPERWEEK; 853 } 854 855 /* 856 ** "d" is the day-of-month (zero-origin) of the day we want. 857 */ 858 value += d * SECSPERDAY; 859 break; 860 } 861 862 /* 863 ** "value" is the Epoch-relative time of 00:00:00 UTC on the day in 864 ** question. To get the Epoch-relative time of the specified local 865 ** time on that day, add the transition time and the current offset 866 ** from UTC. 867 */ 868 return value + rulep->r_time + offset; 869 } 870 871 /* 872 ** Given a POSIX section 8-style TZ string, fill in the rule tables as 873 ** appropriate. 874 */ 875 876 static int 877 tzparse(const char *name, struct state * const sp, const int lastditch) 878 { 879 const char * stdname; 880 const char * dstname; 881 size_t stdlen; 882 size_t dstlen; 883 long stdoffset; 884 long dstoffset; 885 time_t * atp; 886 unsigned char * typep; 887 char * cp; 888 int load_result; 889 static struct ttinfo zttinfo; 890 891 INITIALIZE(dstname); 892 stdname = name; 893 if (lastditch) { 894 stdlen = strlen(name); /* length of standard zone name */ 895 name += stdlen; 896 if (stdlen >= sizeof sp->chars) 897 stdlen = (sizeof sp->chars) - 1; 898 stdoffset = 0; 899 } else { 900 if (*name == '<') { 901 name++; 902 stdname = name; 903 name = getqzname(name, '>'); 904 if (*name != '>') 905 return (-1); 906 stdlen = name - stdname; 907 name++; 908 } else { 909 name = getzname(name); 910 stdlen = name - stdname; 911 } 912 if (*name == '\0') 913 return -1; 914 name = getoffset(name, &stdoffset); 915 if (name == NULL) 916 return -1; 917 } 918 load_result = tzload(TZDEFRULES, sp, FALSE); 919 if (load_result != 0) 920 sp->leapcnt = 0; /* so, we're off a little */ 921 if (*name != '\0') { 922 if (*name == '<') { 923 dstname = ++name; 924 name = getqzname(name, '>'); 925 if (*name != '>') 926 return -1; 927 dstlen = name - dstname; 928 name++; 929 } else { 930 dstname = name; 931 name = getzname(name); 932 dstlen = name - dstname; /* length of DST zone name */ 933 } 934 if (*name != '\0' && *name != ',' && *name != ';') { 935 name = getoffset(name, &dstoffset); 936 if (name == NULL) 937 return -1; 938 } else dstoffset = stdoffset - SECSPERHOUR; 939 if (*name == '\0' && load_result != 0) 940 name = TZDEFRULESTRING; 941 if (*name == ',' || *name == ';') { 942 struct rule start; 943 struct rule end; 944 int year; 945 time_t janfirst; 946 time_t starttime; 947 time_t endtime; 948 949 ++name; 950 if ((name = getrule(name, &start)) == NULL) 951 return -1; 952 if (*name++ != ',') 953 return -1; 954 if ((name = getrule(name, &end)) == NULL) 955 return -1; 956 if (*name != '\0') 957 return -1; 958 sp->typecnt = 2; /* standard time and DST */ 959 /* 960 ** Two transitions per year, from EPOCH_YEAR forward. 961 */ 962 sp->ttis[0] = sp->ttis[1] = zttinfo; 963 sp->ttis[0].tt_gmtoff = -dstoffset; 964 sp->ttis[0].tt_isdst = 1; 965 sp->ttis[0].tt_abbrind = stdlen + 1; 966 sp->ttis[1].tt_gmtoff = -stdoffset; 967 sp->ttis[1].tt_isdst = 0; 968 sp->ttis[1].tt_abbrind = 0; 969 atp = sp->ats; 970 typep = sp->types; 971 janfirst = 0; 972 sp->timecnt = 0; 973 for (year = EPOCH_YEAR; 974 sp->timecnt + 2 <= TZ_MAX_TIMES; 975 ++year) { 976 time_t newfirst; 977 978 starttime = transtime(janfirst, year, &start, 979 stdoffset); 980 endtime = transtime(janfirst, year, &end, 981 dstoffset); 982 if (starttime > endtime) { 983 *atp++ = endtime; 984 *typep++ = 1; /* DST ends */ 985 *atp++ = starttime; 986 *typep++ = 0; /* DST begins */ 987 } else { 988 *atp++ = starttime; 989 *typep++ = 0; /* DST begins */ 990 *atp++ = endtime; 991 *typep++ = 1; /* DST ends */ 992 } 993 sp->timecnt += 2; 994 newfirst = janfirst; 995 newfirst += year_lengths[isleap(year)] * 996 SECSPERDAY; 997 if (newfirst <= janfirst) 998 break; 999 janfirst = newfirst; 1000 } 1001 } else { 1002 long theirstdoffset; 1003 long theirdstoffset; 1004 long theiroffset; 1005 int isdst; 1006 int i; 1007 int j; 1008 1009 if (*name != '\0') 1010 return -1; 1011 /* 1012 ** Initial values of theirstdoffset and theirdstoffset. 1013 */ 1014 theirstdoffset = 0; 1015 for (i = 0; i < sp->timecnt; ++i) { 1016 j = sp->types[i]; 1017 if (!sp->ttis[j].tt_isdst) { 1018 theirstdoffset = 1019 -sp->ttis[j].tt_gmtoff; 1020 break; 1021 } 1022 } 1023 theirdstoffset = 0; 1024 for (i = 0; i < sp->timecnt; ++i) { 1025 j = sp->types[i]; 1026 if (sp->ttis[j].tt_isdst) { 1027 theirdstoffset = 1028 -sp->ttis[j].tt_gmtoff; 1029 break; 1030 } 1031 } 1032 /* 1033 ** Initially we're assumed to be in standard time. 1034 */ 1035 isdst = FALSE; 1036 theiroffset = theirstdoffset; 1037 /* 1038 ** Now juggle transition times and types 1039 ** tracking offsets as you do. 1040 */ 1041 for (i = 0; i < sp->timecnt; ++i) { 1042 j = sp->types[i]; 1043 sp->types[i] = sp->ttis[j].tt_isdst; 1044 if (sp->ttis[j].tt_ttisgmt) { 1045 /* No adjustment to transition time */ 1046 } else { 1047 /* 1048 ** If summer time is in effect, and the 1049 ** transition time was not specified as 1050 ** standard time, add the summer time 1051 ** offset to the transition time; 1052 ** otherwise, add the standard time 1053 ** offset to the transition time. 1054 */ 1055 /* 1056 ** Transitions from DST to DDST 1057 ** will effectively disappear since 1058 ** POSIX provides for only one DST 1059 ** offset. 1060 */ 1061 if (isdst && !sp->ttis[j].tt_ttisstd) { 1062 sp->ats[i] += dstoffset - 1063 theirdstoffset; 1064 } else { 1065 sp->ats[i] += stdoffset - 1066 theirstdoffset; 1067 } 1068 } 1069 theiroffset = -sp->ttis[j].tt_gmtoff; 1070 if (sp->ttis[j].tt_isdst) 1071 theirdstoffset = theiroffset; 1072 else theirstdoffset = theiroffset; 1073 } 1074 /* 1075 ** Finally, fill in ttis. 1076 */ 1077 sp->ttis[0] = sp->ttis[1] = zttinfo; 1078 sp->ttis[0].tt_gmtoff = -stdoffset; 1079 sp->ttis[0].tt_isdst = FALSE; 1080 sp->ttis[0].tt_abbrind = 0; 1081 sp->ttis[1].tt_gmtoff = -dstoffset; 1082 sp->ttis[1].tt_isdst = TRUE; 1083 sp->ttis[1].tt_abbrind = stdlen + 1; 1084 sp->typecnt = 2; 1085 } 1086 } else { 1087 dstlen = 0; 1088 sp->typecnt = 1; /* only standard time */ 1089 sp->timecnt = 0; 1090 sp->ttis[0] = zttinfo; 1091 sp->ttis[0].tt_gmtoff = -stdoffset; 1092 sp->ttis[0].tt_isdst = 0; 1093 sp->ttis[0].tt_abbrind = 0; 1094 } 1095 sp->charcnt = stdlen + 1; 1096 if (dstlen != 0) 1097 sp->charcnt += dstlen + 1; 1098 if ((size_t) sp->charcnt > sizeof sp->chars) 1099 return -1; 1100 cp = sp->chars; 1101 strncpy(cp, stdname, stdlen); 1102 cp += stdlen; 1103 *cp++ = '\0'; 1104 if (dstlen != 0) { 1105 strncpy(cp, dstname, dstlen); 1106 *(cp + dstlen) = '\0'; 1107 } 1108 return 0; 1109 } 1110 1111 static void 1112 gmtload(struct state * const sp) 1113 { 1114 if (tzload(gmt, sp, TRUE) != 0) 1115 tzparse(gmt, sp, TRUE); 1116 } 1117 1118 static void 1119 tzsetwall_basic(int rdlocked) 1120 { 1121 if (!rdlocked) 1122 _RWLOCK_RDLOCK(&lcl_rwlock); 1123 if (lcl_is_set < 0) { 1124 if (!rdlocked) 1125 _RWLOCK_UNLOCK(&lcl_rwlock); 1126 return; 1127 } 1128 _RWLOCK_UNLOCK(&lcl_rwlock); 1129 1130 _RWLOCK_WRLOCK(&lcl_rwlock); 1131 lcl_is_set = -1; 1132 1133 if (tzload(NULL, lclptr, TRUE) != 0) 1134 gmtload(lclptr); 1135 settzname(); 1136 _RWLOCK_UNLOCK(&lcl_rwlock); 1137 1138 if (rdlocked) 1139 _RWLOCK_RDLOCK(&lcl_rwlock); 1140 } 1141 1142 void 1143 tzsetwall(void) 1144 { 1145 tzsetwall_basic(0); 1146 } 1147 1148 static void 1149 tzset_basic(int rdlocked) 1150 { 1151 const char * name; 1152 1153 name = getenv("TZ"); 1154 if (name == NULL) { 1155 tzsetwall_basic(rdlocked); 1156 return; 1157 } 1158 1159 if (!rdlocked) 1160 _RWLOCK_RDLOCK(&lcl_rwlock); 1161 if (lcl_is_set > 0 && strcmp(lcl_TZname, name) == 0) { 1162 if (!rdlocked) 1163 _RWLOCK_UNLOCK(&lcl_rwlock); 1164 return; 1165 } 1166 _RWLOCK_UNLOCK(&lcl_rwlock); 1167 1168 _RWLOCK_WRLOCK(&lcl_rwlock); 1169 lcl_is_set = strlen(name) < sizeof lcl_TZname; 1170 if (lcl_is_set) 1171 strcpy(lcl_TZname, name); 1172 1173 if (*name == '\0') { 1174 /* 1175 ** User wants it fast rather than right. 1176 */ 1177 lclptr->leapcnt = 0; /* so, we're off a little */ 1178 lclptr->timecnt = 0; 1179 lclptr->typecnt = 0; 1180 lclptr->ttis[0].tt_isdst = 0; 1181 lclptr->ttis[0].tt_gmtoff = 0; 1182 lclptr->ttis[0].tt_abbrind = 0; 1183 strcpy(lclptr->chars, gmt); 1184 } else if (tzload(name, lclptr, TRUE) != 0) 1185 if (name[0] == ':' || tzparse(name, lclptr, FALSE) != 0) 1186 gmtload(lclptr); 1187 settzname(); 1188 _RWLOCK_UNLOCK(&lcl_rwlock); 1189 1190 if (rdlocked) 1191 _RWLOCK_RDLOCK(&lcl_rwlock); 1192 } 1193 1194 void 1195 tzset(void) 1196 { 1197 tzset_basic(0); 1198 } 1199 1200 /* 1201 ** The easy way to behave "as if no library function calls" localtime 1202 ** is to not call it--so we drop its guts into "localsub", which can be 1203 ** freely called. (And no, the PANS doesn't require the above behavior-- 1204 ** but it *is* desirable.) 1205 ** 1206 ** The unused offset argument is for the benefit of mktime variants. 1207 */ 1208 1209 /*ARGSUSED*/ 1210 static struct tm * 1211 localsub(const time_t * const timep, const long offset __unused, 1212 struct tm * const tmp) 1213 { 1214 struct state * sp; 1215 const struct ttinfo * ttisp; 1216 int i; 1217 struct tm * result; 1218 const time_t t = *timep; 1219 1220 sp = lclptr; 1221 1222 if ((sp->goback && t < sp->ats[0]) || 1223 (sp->goahead && t > sp->ats[sp->timecnt - 1])) { 1224 time_t newt = t; 1225 time_t seconds; 1226 time_t tcycles; 1227 int_fast64_t icycles; 1228 1229 if (t < sp->ats[0]) 1230 seconds = sp->ats[0] - t; 1231 else seconds = t - sp->ats[sp->timecnt - 1]; 1232 --seconds; 1233 tcycles = seconds / YEARSPERREPEAT / AVGSECSPERYEAR; 1234 ++tcycles; 1235 icycles = tcycles; 1236 if (tcycles - icycles >= 1 || icycles - tcycles >= 1) 1237 return NULL; 1238 seconds = icycles; 1239 seconds *= YEARSPERREPEAT; 1240 seconds *= AVGSECSPERYEAR; 1241 if (t < sp->ats[0]) 1242 newt += seconds; 1243 else newt -= seconds; 1244 if (newt < sp->ats[0] || 1245 newt > sp->ats[sp->timecnt - 1]) 1246 return NULL; /* "cannot happen" */ 1247 result = localsub(&newt, offset, tmp); 1248 if (result == tmp) { 1249 time_t newy; 1250 1251 newy = tmp->tm_year; 1252 if (t < sp->ats[0]) 1253 newy -= icycles * YEARSPERREPEAT; 1254 else newy += icycles * YEARSPERREPEAT; 1255 tmp->tm_year = newy; 1256 if (tmp->tm_year != newy) 1257 return NULL; 1258 } 1259 return result; 1260 } 1261 if (sp->timecnt == 0 || t < sp->ats[0]) { 1262 i = 0; 1263 while (sp->ttis[i].tt_isdst) 1264 if (++i >= sp->typecnt) { 1265 i = 0; 1266 break; 1267 } 1268 } else { 1269 int lo = 1; 1270 int hi = sp->timecnt; 1271 1272 while (lo < hi) { 1273 int mid = (lo + hi) >> 1; 1274 1275 if (t < sp->ats[mid]) 1276 hi = mid; 1277 else lo = mid + 1; 1278 } 1279 i = (int) sp->types[lo - 1]; 1280 } 1281 ttisp = &sp->ttis[i]; 1282 /* 1283 ** To get (wrong) behavior that's compatible with System V Release 2.0 1284 ** you'd replace the statement below with 1285 ** t += ttisp->tt_gmtoff; 1286 ** timesub(&t, 0L, sp, tmp); 1287 */ 1288 result = timesub(&t, ttisp->tt_gmtoff, sp, tmp); 1289 tmp->tm_isdst = ttisp->tt_isdst; 1290 tzname[tmp->tm_isdst] = &sp->chars[ttisp->tt_abbrind]; 1291 #ifdef TM_ZONE 1292 tmp->TM_ZONE = &sp->chars[ttisp->tt_abbrind]; 1293 #endif /* defined TM_ZONE */ 1294 return result; 1295 } 1296 1297 struct tm * 1298 localtime_r(const time_t * const timep, struct tm *p_tm) 1299 { 1300 _RWLOCK_RDLOCK(&lcl_rwlock); 1301 tzset_basic(1); 1302 localsub(timep, 0L, p_tm); 1303 _RWLOCK_UNLOCK(&lcl_rwlock); 1304 return(p_tm); 1305 } 1306 1307 struct tm * 1308 localtime(const time_t * const timep) 1309 { 1310 static pthread_mutex_t localtime_mutex = PTHREAD_MUTEX_INITIALIZER; 1311 static pthread_key_t localtime_key = -1; 1312 struct tm *p_tm; 1313 1314 if (__isthreaded != 0) { 1315 if (localtime_key < 0) { 1316 _pthread_mutex_lock(&localtime_mutex); 1317 if (localtime_key < 0) { 1318 if (_pthread_key_create(&localtime_key, free) < 0) { 1319 _pthread_mutex_unlock(&localtime_mutex); 1320 return(NULL); 1321 } 1322 } 1323 _pthread_mutex_unlock(&localtime_mutex); 1324 } 1325 p_tm = _pthread_getspecific(localtime_key); 1326 if (p_tm == NULL) { 1327 if ((p_tm = (struct tm *)malloc(sizeof(struct tm))) 1328 == NULL) 1329 return(NULL); 1330 _pthread_setspecific(localtime_key, p_tm); 1331 } 1332 _RWLOCK_RDLOCK(&lcl_rwlock); 1333 tzset_basic(1); 1334 localsub(timep, 0L, p_tm); 1335 _RWLOCK_UNLOCK(&lcl_rwlock); 1336 return(p_tm); 1337 } else { 1338 tzset_basic(0); 1339 localsub(timep, 0L, &tm); 1340 return(&tm); 1341 } 1342 } 1343 1344 /* 1345 ** gmtsub is to gmtime as localsub is to localtime. 1346 */ 1347 1348 static struct tm * 1349 gmtsub(const time_t * const timep, const long offset, struct tm * const tmp) 1350 { 1351 struct tm * result; 1352 1353 if (!gmt_is_set) { 1354 _MUTEX_LOCK(&gmt_mutex); 1355 if (!gmt_is_set) { 1356 gmtload(gmtptr); 1357 gmt_is_set = TRUE; 1358 } 1359 _MUTEX_UNLOCK(&gmt_mutex); 1360 } 1361 result = timesub(timep, offset, gmtptr, tmp); 1362 #ifdef TM_ZONE 1363 /* 1364 ** Could get fancy here and deliver something such as 1365 ** "UTC+xxxx" or "UTC-xxxx" if offset is non-zero, 1366 ** but this is no time for a treasure hunt. 1367 */ 1368 if (offset != 0) 1369 tmp->TM_ZONE = wildabbr; 1370 else 1371 tmp->TM_ZONE = gmtptr->chars; 1372 #endif /* defined TM_ZONE */ 1373 return result; 1374 } 1375 1376 struct tm * 1377 gmtime(const time_t * const timep) 1378 { 1379 static pthread_mutex_t gmtime_mutex = PTHREAD_MUTEX_INITIALIZER; 1380 static pthread_key_t gmtime_key = -1; 1381 struct tm *p_tm; 1382 1383 if (__isthreaded != 0) { 1384 if (gmtime_key < 0) { 1385 _pthread_mutex_lock(&gmtime_mutex); 1386 if (gmtime_key < 0) { 1387 if (_pthread_key_create(&gmtime_key, free) < 0) { 1388 _pthread_mutex_unlock(&gmtime_mutex); 1389 return(NULL); 1390 } 1391 } 1392 _pthread_mutex_unlock(&gmtime_mutex); 1393 } 1394 /* 1395 * Changed to follow POSIX.1 threads standard, which 1396 * is what BSD currently has. 1397 */ 1398 if ((p_tm = _pthread_getspecific(gmtime_key)) == NULL) { 1399 if ((p_tm = (struct tm *)malloc(sizeof(struct tm))) 1400 == NULL) { 1401 return(NULL); 1402 } 1403 _pthread_setspecific(gmtime_key, p_tm); 1404 } 1405 return gmtsub(timep, 0L, p_tm); 1406 } else { 1407 return gmtsub(timep, 0L, &tm); 1408 } 1409 } 1410 1411 struct tm * 1412 gmtime_r(const time_t * timep, struct tm * tmp) 1413 { 1414 return gmtsub(timep, 0L, tmp); 1415 } 1416 1417 struct tm * 1418 offtime(const time_t * const timep, const long offset) 1419 { 1420 return gmtsub(timep, offset, &tm); 1421 } 1422 1423 /* 1424 ** Return the number of leap years through the end of the given year 1425 ** where, to make the math easy, the answer for year zero is defined as zero. 1426 */ 1427 1428 static int 1429 leaps_thru_end_of(const int y) 1430 { 1431 return (y >= 0) ? (y / 4 - y / 100 + y / 400) : 1432 -(leaps_thru_end_of(-(y + 1)) + 1); 1433 } 1434 1435 static struct tm * 1436 timesub(const time_t * const timep, const long offset, 1437 const struct state * const sp, struct tm * const tmp) 1438 { 1439 const struct lsinfo * lp; 1440 time_t tdays; 1441 int idays; /* unsigned would be so 2003 */ 1442 long rem; 1443 int y; 1444 int yleap; 1445 const int * ip; 1446 long corr; 1447 int hit; 1448 int i; 1449 1450 corr = 0; 1451 hit = 0; 1452 i = sp->leapcnt; 1453 1454 while (--i >= 0) { 1455 lp = &sp->lsis[i]; 1456 if (*timep >= lp->ls_trans) { 1457 if (*timep == lp->ls_trans) { 1458 hit = ((i == 0 && lp->ls_corr > 0) || 1459 lp->ls_corr > sp->lsis[i - 1].ls_corr); 1460 if (hit) 1461 while (i > 0 && 1462 sp->lsis[i].ls_trans == 1463 sp->lsis[i - 1].ls_trans + 1 && 1464 sp->lsis[i].ls_corr == 1465 sp->lsis[i - 1].ls_corr + 1) { 1466 ++hit; 1467 --i; 1468 } 1469 } 1470 corr = lp->ls_corr; 1471 break; 1472 } 1473 } 1474 y = EPOCH_YEAR; 1475 tdays = *timep / SECSPERDAY; 1476 rem = *timep - tdays * SECSPERDAY; 1477 while (tdays < 0 || tdays >= year_lengths[isleap(y)]) { 1478 int newy; 1479 time_t tdelta; 1480 int idelta; 1481 int leapdays; 1482 1483 tdelta = tdays / DAYSPERLYEAR; 1484 idelta = tdelta; 1485 if (tdelta - idelta >= 1 || idelta - tdelta >= 1) 1486 return NULL; 1487 if (idelta == 0) 1488 idelta = (tdays < 0) ? -1 : 1; 1489 newy = y; 1490 if (increment_overflow(&newy, idelta)) 1491 return NULL; 1492 leapdays = leaps_thru_end_of(newy - 1) - 1493 leaps_thru_end_of(y - 1); 1494 tdays -= ((time_t) newy - y) * DAYSPERNYEAR; 1495 tdays -= leapdays; 1496 y = newy; 1497 } 1498 { 1499 long seconds; 1500 1501 seconds = tdays * SECSPERDAY + 0.5; 1502 tdays = seconds / SECSPERDAY; 1503 rem += seconds - tdays * SECSPERDAY; 1504 } 1505 /* 1506 ** Given the range, we can now fearlessly cast... 1507 */ 1508 idays = tdays; 1509 rem += offset - corr; 1510 while (rem < 0) { 1511 rem += SECSPERDAY; 1512 --idays; 1513 } 1514 while (rem >= SECSPERDAY) { 1515 rem -= SECSPERDAY; 1516 ++idays; 1517 } 1518 while (idays < 0) { 1519 if (increment_overflow(&y, -1)) 1520 return NULL; 1521 idays += year_lengths[isleap(y)]; 1522 } 1523 while (idays >= year_lengths[isleap(y)]) { 1524 idays -= year_lengths[isleap(y)]; 1525 if (increment_overflow(&y, 1)) 1526 return NULL; 1527 } 1528 tmp->tm_year = y; 1529 if (increment_overflow(&tmp->tm_year, -TM_YEAR_BASE)) 1530 return NULL; 1531 tmp->tm_yday = idays; 1532 /* 1533 ** The "extra" mods below avoid overflow problems. 1534 */ 1535 tmp->tm_wday = EPOCH_WDAY + 1536 ((y - EPOCH_YEAR) % DAYSPERWEEK) * 1537 (DAYSPERNYEAR % DAYSPERWEEK) + 1538 leaps_thru_end_of(y - 1) - 1539 leaps_thru_end_of(EPOCH_YEAR - 1) + 1540 idays; 1541 tmp->tm_wday %= DAYSPERWEEK; 1542 if (tmp->tm_wday < 0) 1543 tmp->tm_wday += DAYSPERWEEK; 1544 tmp->tm_hour = (int) (rem / SECSPERHOUR); 1545 rem %= SECSPERHOUR; 1546 tmp->tm_min = (int) (rem / SECSPERMIN); 1547 /* 1548 ** A positive leap second requires a special 1549 ** representation. This uses "... ??:59:60" et seq. 1550 */ 1551 tmp->tm_sec = (int) (rem % SECSPERMIN) + hit; 1552 ip = mon_lengths[isleap(y)]; 1553 for (tmp->tm_mon = 0; idays >= ip[tmp->tm_mon]; ++(tmp->tm_mon)) 1554 idays -= ip[tmp->tm_mon]; 1555 tmp->tm_mday = (int) (idays + 1); 1556 tmp->tm_isdst = 0; 1557 #ifdef TM_GMTOFF 1558 tmp->TM_GMTOFF = offset; 1559 #endif /* defined TM_GMTOFF */ 1560 return tmp; 1561 } 1562 1563 char * 1564 ctime(const time_t * const timep) 1565 { 1566 /* 1567 ** Section 4.12.3.2 of X3.159-1989 requires that 1568 ** The ctime function converts the calendar time pointed to by timer 1569 ** to local time in the form of a string. It is equivalent to 1570 ** asctime(localtime(timer)) 1571 */ 1572 return asctime(localtime(timep)); 1573 } 1574 1575 char * 1576 ctime_r(const time_t * const timep, char *buf) 1577 { 1578 struct tm mytm; 1579 return asctime_r(localtime_r(timep, &mytm), buf); 1580 } 1581 1582 /* 1583 ** Adapted from code provided by Robert Elz, who writes: 1584 ** The "best" way to do mktime I think is based on an idea of Bob 1585 ** Kridle's (so its said...) from a long time ago. 1586 ** It does a binary search of the time_t space. Since time_t's are 1587 ** just 32 bits, its a max of 32 iterations (even at 64 bits it 1588 ** would still be very reasonable). 1589 */ 1590 1591 #ifndef WRONG 1592 #define WRONG (-1) 1593 #endif /* !defined WRONG */ 1594 1595 /* 1596 ** Simplified normalize logic courtesy Paul Eggert. 1597 */ 1598 1599 static int 1600 increment_overflow(int *number, int delta) 1601 { 1602 int number0; 1603 1604 number0 = *number; 1605 *number += delta; 1606 return (*number < number0) != (delta < 0); 1607 } 1608 1609 static int 1610 long_increment_overflow(long *number, int delta) 1611 { 1612 long number0; 1613 1614 number0 = *number; 1615 *number += delta; 1616 return (*number < number0) != (delta < 0); 1617 } 1618 1619 static int 1620 normalize_overflow(int * const tensptr, int * const unitsptr, const int base) 1621 { 1622 int tensdelta; 1623 1624 tensdelta = (*unitsptr >= 0) ? 1625 (*unitsptr / base) : 1626 (-1 - (-1 - *unitsptr) / base); 1627 *unitsptr -= tensdelta * base; 1628 return increment_overflow(tensptr, tensdelta); 1629 } 1630 1631 static int 1632 long_normalize_overflow(long * const tensptr, int * const unitsptr, 1633 const int base) 1634 { 1635 int tensdelta; 1636 1637 tensdelta = (*unitsptr >= 0) ? 1638 (*unitsptr / base) : 1639 (-1 - (-1 - *unitsptr) / base); 1640 *unitsptr -= tensdelta * base; 1641 return long_increment_overflow(tensptr, tensdelta); 1642 } 1643 1644 static int 1645 tmcomp(const struct tm * const atmp, const struct tm * const btmp) 1646 { 1647 int result; 1648 1649 if ((result = (atmp->tm_year - btmp->tm_year)) == 0 && 1650 (result = (atmp->tm_mon - btmp->tm_mon)) == 0 && 1651 (result = (atmp->tm_mday - btmp->tm_mday)) == 0 && 1652 (result = (atmp->tm_hour - btmp->tm_hour)) == 0 && 1653 (result = (atmp->tm_min - btmp->tm_min)) == 0) 1654 result = atmp->tm_sec - btmp->tm_sec; 1655 return result; 1656 } 1657 1658 static time_t 1659 time2sub(struct tm * const tmp, 1660 struct tm * (* const funcp)(const time_t *, long, struct tm *), 1661 const long offset, int * const okayp, const int do_norm_secs) 1662 { 1663 const struct state * sp; 1664 int dir; 1665 int i, j; 1666 int saved_seconds; 1667 long li; 1668 time_t lo; 1669 time_t hi; 1670 long y; 1671 time_t newt; 1672 time_t t; 1673 struct tm yourtm, mytm; 1674 1675 *okayp = FALSE; 1676 yourtm = *tmp; 1677 if (do_norm_secs) { 1678 if (normalize_overflow(&yourtm.tm_min, &yourtm.tm_sec, 1679 SECSPERMIN)) 1680 return WRONG; 1681 } 1682 if (normalize_overflow(&yourtm.tm_hour, &yourtm.tm_min, MINSPERHOUR)) 1683 return WRONG; 1684 if (normalize_overflow(&yourtm.tm_mday, &yourtm.tm_hour, HOURSPERDAY)) 1685 return WRONG; 1686 y = yourtm.tm_year; 1687 if (long_normalize_overflow(&y, &yourtm.tm_mon, MONSPERYEAR)) 1688 return WRONG; 1689 /* 1690 ** Turn y into an actual year number for now. 1691 ** It is converted back to an offset from TM_YEAR_BASE later. 1692 */ 1693 if (long_increment_overflow(&y, TM_YEAR_BASE)) 1694 return WRONG; 1695 while (yourtm.tm_mday <= 0) { 1696 if (long_increment_overflow(&y, -1)) 1697 return WRONG; 1698 li = y + (1 < yourtm.tm_mon); 1699 yourtm.tm_mday += year_lengths[isleap(li)]; 1700 } 1701 while (yourtm.tm_mday > DAYSPERLYEAR) { 1702 li = y + (1 < yourtm.tm_mon); 1703 yourtm.tm_mday -= year_lengths[isleap(li)]; 1704 if (long_increment_overflow(&y, 1)) 1705 return WRONG; 1706 } 1707 for ( ; ; ) { 1708 i = mon_lengths[isleap(y)][yourtm.tm_mon]; 1709 if (yourtm.tm_mday <= i) 1710 break; 1711 yourtm.tm_mday -= i; 1712 if (++yourtm.tm_mon >= MONSPERYEAR) { 1713 yourtm.tm_mon = 0; 1714 if (long_increment_overflow(&y, 1)) 1715 return WRONG; 1716 } 1717 } 1718 if (long_increment_overflow(&y, -TM_YEAR_BASE)) 1719 return WRONG; 1720 yourtm.tm_year = y; 1721 if (yourtm.tm_year != y) 1722 return WRONG; 1723 if (yourtm.tm_sec >= 0 && yourtm.tm_sec < SECSPERMIN) 1724 saved_seconds = 0; 1725 else if (y + TM_YEAR_BASE < EPOCH_YEAR) { 1726 /* 1727 ** We can't set tm_sec to 0, because that might push the 1728 ** time below the minimum representable time. 1729 ** Set tm_sec to 59 instead. 1730 ** This assumes that the minimum representable time is 1731 ** not in the same minute that a leap second was deleted from, 1732 ** which is a safer assumption than using 58 would be. 1733 */ 1734 if (increment_overflow(&yourtm.tm_sec, 1 - SECSPERMIN)) 1735 return WRONG; 1736 saved_seconds = yourtm.tm_sec; 1737 yourtm.tm_sec = SECSPERMIN - 1; 1738 } else { 1739 saved_seconds = yourtm.tm_sec; 1740 yourtm.tm_sec = 0; 1741 } 1742 /* 1743 ** Do a binary search (this works whatever time_t's type is). 1744 */ 1745 if (!TYPE_SIGNED(time_t)) { 1746 lo = 0; 1747 hi = lo - 1; 1748 } else if (!TYPE_INTEGRAL(time_t)) { 1749 if (sizeof(time_t) > sizeof(float)) 1750 hi = (time_t) DBL_MAX; 1751 else hi = (time_t) FLT_MAX; 1752 lo = -hi; 1753 } else { 1754 lo = 1; 1755 for (i = 0; i < (int) TYPE_BIT(time_t) - 1; ++i) 1756 lo *= 2; 1757 hi = -(lo + 1); 1758 } 1759 for ( ; ; ) { 1760 t = lo / 2 + hi / 2; 1761 if (t < lo) 1762 t = lo; 1763 else if (t > hi) 1764 t = hi; 1765 if ((*funcp)(&t, offset, &mytm) == NULL) { 1766 /* 1767 ** Assume that t is too extreme to be represented in 1768 ** a struct tm; arrange things so that it is less 1769 ** extreme on the next pass. 1770 */ 1771 dir = (t > 0) ? 1 : -1; 1772 } else dir = tmcomp(&mytm, &yourtm); 1773 if (dir != 0) { 1774 if (t == lo) { 1775 ++t; 1776 if (t <= lo) 1777 return WRONG; 1778 ++lo; 1779 } else if (t == hi) { 1780 --t; 1781 if (t >= hi) 1782 return WRONG; 1783 --hi; 1784 } 1785 if (lo > hi) 1786 return WRONG; 1787 if (dir > 0) 1788 hi = t; 1789 else lo = t; 1790 continue; 1791 } 1792 if (yourtm.tm_isdst < 0 || mytm.tm_isdst == yourtm.tm_isdst) 1793 break; 1794 /* 1795 ** Right time, wrong type. 1796 ** Hunt for right time, right type. 1797 ** It's okay to guess wrong since the guess 1798 ** gets checked. 1799 */ 1800 sp = (const struct state *) 1801 ((funcp == localsub) ? lclptr : gmtptr); 1802 1803 for (i = sp->typecnt - 1; i >= 0; --i) { 1804 if (sp->ttis[i].tt_isdst != yourtm.tm_isdst) 1805 continue; 1806 for (j = sp->typecnt - 1; j >= 0; --j) { 1807 if (sp->ttis[j].tt_isdst == yourtm.tm_isdst) 1808 continue; 1809 newt = t + sp->ttis[j].tt_gmtoff - 1810 sp->ttis[i].tt_gmtoff; 1811 if ((*funcp)(&newt, offset, &mytm) == NULL) 1812 continue; 1813 if (tmcomp(&mytm, &yourtm) != 0) 1814 continue; 1815 if (mytm.tm_isdst != yourtm.tm_isdst) 1816 continue; 1817 /* 1818 ** We have a match. 1819 */ 1820 t = newt; 1821 goto label; 1822 } 1823 } 1824 return WRONG; 1825 } 1826 label: 1827 newt = t + saved_seconds; 1828 if ((newt < t) != (saved_seconds < 0)) 1829 return WRONG; 1830 t = newt; 1831 if ((*funcp)(&t, offset, tmp)) 1832 *okayp = TRUE; 1833 return t; 1834 } 1835 1836 static time_t 1837 time2(struct tm * const tmp, 1838 struct tm * (* const funcp)(const time_t *, long, struct tm *), 1839 const long offset, int * const okayp) 1840 { 1841 time_t t; 1842 1843 /* 1844 ** First try without normalization of seconds 1845 ** (in case tm_sec contains a value associated with a leap second). 1846 ** If that fails, try with normalization of seconds. 1847 */ 1848 t = time2sub(tmp, funcp, offset, okayp, FALSE); 1849 return *okayp ? t : time2sub(tmp, funcp, offset, okayp, TRUE); 1850 } 1851 1852 static time_t 1853 time1(struct tm * const tmp, 1854 struct tm * (* const funcp)(const time_t *, long, struct tm *), 1855 const long offset) 1856 { 1857 time_t t; 1858 const struct state * sp; 1859 int samei, otheri; 1860 int sameind, otherind; 1861 int i; 1862 int nseen; 1863 int seen[TZ_MAX_TYPES]; 1864 int types[TZ_MAX_TYPES]; 1865 int okay; 1866 1867 if (tmp == NULL) { 1868 errno = EINVAL; 1869 return WRONG; 1870 } 1871 if (tmp->tm_isdst > 1) 1872 tmp->tm_isdst = 1; 1873 t = time2(tmp, funcp, offset, &okay); 1874 1875 /* 1876 ** PCTS code courtesy Grant Sullivan. 1877 */ 1878 if (okay) 1879 return t; 1880 if (tmp->tm_isdst < 0) 1881 tmp->tm_isdst = 0; /* reset to std and try again */ 1882 1883 /* 1884 ** We're supposed to assume that somebody took a time of one type 1885 ** and did some math on it that yielded a "struct tm" that's bad. 1886 ** We try to divine the type they started from and adjust to the 1887 ** type they need. 1888 */ 1889 sp = (const struct state *) ((funcp == localsub) ? lclptr : gmtptr); 1890 1891 for (i = 0; i < sp->typecnt; ++i) 1892 seen[i] = FALSE; 1893 nseen = 0; 1894 for (i = sp->timecnt - 1; i >= 0; --i) 1895 if (!seen[sp->types[i]]) { 1896 seen[sp->types[i]] = TRUE; 1897 types[nseen++] = sp->types[i]; 1898 } 1899 for (sameind = 0; sameind < nseen; ++sameind) { 1900 samei = types[sameind]; 1901 if (sp->ttis[samei].tt_isdst != tmp->tm_isdst) 1902 continue; 1903 for (otherind = 0; otherind < nseen; ++otherind) { 1904 otheri = types[otherind]; 1905 if (sp->ttis[otheri].tt_isdst == tmp->tm_isdst) 1906 continue; 1907 tmp->tm_sec += sp->ttis[otheri].tt_gmtoff - 1908 sp->ttis[samei].tt_gmtoff; 1909 tmp->tm_isdst = !tmp->tm_isdst; 1910 t = time2(tmp, funcp, offset, &okay); 1911 if (okay) 1912 return t; 1913 tmp->tm_sec -= sp->ttis[otheri].tt_gmtoff - 1914 sp->ttis[samei].tt_gmtoff; 1915 tmp->tm_isdst = !tmp->tm_isdst; 1916 } 1917 } 1918 return WRONG; 1919 } 1920 1921 time_t 1922 mktime(struct tm * const tmp) 1923 { 1924 time_t mktime_return_value; 1925 _RWLOCK_RDLOCK(&lcl_rwlock); 1926 tzset_basic(1); 1927 mktime_return_value = time1(tmp, localsub, 0L); 1928 _RWLOCK_UNLOCK(&lcl_rwlock); 1929 return(mktime_return_value); 1930 } 1931 1932 time_t 1933 timelocal(struct tm * const tmp) 1934 { 1935 if (tmp != NULL) 1936 tmp->tm_isdst = -1; /* in case it wasn't initialized */ 1937 return mktime(tmp); 1938 } 1939 1940 time_t 1941 timegm(struct tm * const tmp) 1942 { 1943 if (tmp != NULL) 1944 tmp->tm_isdst = 0; 1945 return time1(tmp, gmtsub, 0L); 1946 } 1947 1948 time_t 1949 timeoff(struct tm * const tmp, const long offset) 1950 { 1951 if (tmp != NULL) 1952 tmp->tm_isdst = 0; 1953 return time1(tmp, gmtsub, offset); 1954 } 1955 1956 #ifdef CMUCS 1957 1958 /* 1959 ** The following is supplied for compatibility with 1960 ** previous versions of the CMUCS runtime library. 1961 */ 1962 1963 long 1964 gtime(struct tm * const tmp) 1965 { 1966 const time_t t = mktime(tmp); 1967 1968 if (t == WRONG) 1969 return -1; 1970 return t; 1971 } 1972 1973 #endif /* defined CMUCS */ 1974 1975 /* 1976 ** XXX--is the below the right way to conditionalize?? 1977 */ 1978 1979 /* 1980 ** IEEE Std 1003.1-1988 (POSIX) legislates that 536457599 1981 ** shall correspond to "Wed Dec 31 23:59:59 UTC 1986", which 1982 ** is not the case if we are accounting for leap seconds. 1983 ** So, we provide the following conversion routines for use 1984 ** when exchanging timestamps with POSIX conforming systems. 1985 */ 1986 1987 static long 1988 leapcorr(time_t *timep) 1989 { 1990 struct state * sp; 1991 struct lsinfo * lp; 1992 int i; 1993 1994 sp = lclptr; 1995 i = sp->leapcnt; 1996 while (--i >= 0) { 1997 lp = &sp->lsis[i]; 1998 if (*timep >= lp->ls_trans) 1999 return lp->ls_corr; 2000 } 2001 return 0; 2002 } 2003 2004 time_t 2005 time2posix(time_t t) 2006 { 2007 tzset(); 2008 return t - leapcorr(&t); 2009 } 2010 2011 time_t 2012 posix2time(time_t t) 2013 { 2014 time_t x; 2015 time_t y; 2016 2017 tzset(); 2018 /* 2019 ** For a positive leap second hit, the result 2020 ** is not unique. For a negative leap second 2021 ** hit, the corresponding time doesn't exist, 2022 ** so we return an adjacent second. 2023 */ 2024 x = t + leapcorr(&t); 2025 y = x - leapcorr(&x); 2026 if (y < t) { 2027 do { 2028 x++; 2029 y = x - leapcorr(&x); 2030 } while (y < t); 2031 if (t != y) 2032 return x - 1; 2033 } else if (y > t) { 2034 do { 2035 --x; 2036 y = x - leapcorr(&x); 2037 } while (y > t); 2038 if (t != y) 2039 return x + 1; 2040 } 2041 return x; 2042 } 2043