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