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 8.9 6 ** $FreeBSD: src/lib/libc/stdtime/localtime.c,v 1.25.2.2 2002/08/13 16:08:07 bmilekic Exp $ 7 ** $DragonFly: src/lib/libc/stdtime/localtime.c,v 1.7 2008/10/19 20:15:58 swildner Exp $ 8 */ 9 10 /* 11 ** Leap second handling from Bradley White. 12 ** POSIX-style TZ environment variable handling from Guy Harris. 13 */ 14 15 /*LINTLIBRARY*/ 16 17 #include "namespace.h" 18 #include <sys/types.h> 19 #include <sys/stat.h> 20 21 #include <fcntl.h> 22 #include <float.h> /* for FLT_MAX and DBL_MAX */ 23 #include <time.h> 24 #include <pthread.h> 25 #include "private.h" 26 #include <un-namespace.h> 27 28 #include "tzfile.h" 29 30 #include "libc_private.h" 31 32 #define _MUTEX_LOCK(x) if (__isthreaded) _pthread_mutex_lock(x) 33 #define _MUTEX_UNLOCK(x) if (__isthreaded) _pthread_mutex_unlock(x) 34 35 #define _RWLOCK_RDLOCK(x) \ 36 do { \ 37 if (__isthreaded) _pthread_rwlock_rdlock(x); \ 38 } while (0) 39 40 #define _RWLOCK_WRLOCK(x) \ 41 do { \ 42 if (__isthreaded) _pthread_rwlock_wrlock(x); \ 43 } while (0) 44 45 #define _RWLOCK_UNLOCK(x) \ 46 do { \ 47 if (__isthreaded) _pthread_rwlock_unlock(x); \ 48 } while (0) 49 50 #ifndef TZ_ABBR_MAX_LEN 51 #define TZ_ABBR_MAX_LEN 16 52 #endif /* !defined TZ_ABBR_MAX_LEN */ 53 54 #ifndef TZ_ABBR_CHAR_SET 55 #define TZ_ABBR_CHAR_SET \ 56 "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789 :+-._" 57 #endif /* !defined TZ_ABBR_CHAR_SET */ 58 59 #ifndef TZ_ABBR_ERR_CHAR 60 #define TZ_ABBR_ERR_CHAR '_' 61 #endif /* !defined TZ_ABBR_ERR_CHAR */ 62 63 /* 64 ** Someone might make incorrect use of a time zone abbreviation: 65 ** 1. They might reference tzname[0] before calling tzset (explicitly 66 ** or implicitly). 67 ** 2. They might reference tzname[1] before calling tzset (explicitly 68 ** or implicitly). 69 ** 3. They might reference tzname[1] after setting to a time zone 70 ** in which Daylight Saving Time is never observed. 71 ** 4. They might reference tzname[0] after setting to a time zone 72 ** in which Standard Time is never observed. 73 ** 5. They might reference tm.TM_ZONE after calling offtime. 74 ** What's best to do in the above cases is open to debate; 75 ** for now, we just set things up so that in any of the five cases 76 ** WILDABBR is used. Another possibility: initialize tzname[0] to the 77 ** string "tzname[0] used before set", and similarly for the other cases. 78 ** And another: initialize tzname[0] to "ERA", with an explanation in the 79 ** manual page of what this "time zone abbreviation" means (doing this so 80 ** that tzname[0] has the "normal" length of three characters). 81 */ 82 #define WILDABBR " " 83 84 static char wildabbr[] = WILDABBR; 85 86 static const char gmt[] = "UTC"; 87 88 /* 89 ** The DST rules to use if TZ has no rules and we can't load TZDEFRULES. 90 ** We default to US rules as of 1999-08-17. 91 ** POSIX 1003.1 section 8.1.1 says that the default DST rules are 92 ** implementation dependent; for historical reasons, US rules are a 93 ** common default. 94 */ 95 #ifndef TZDEFRULESTRING 96 #define TZDEFRULESTRING ",M4.1.0,M10.5.0" 97 #endif /* !defined TZDEFDST */ 98 99 struct ttinfo { /* time type information */ 100 long tt_gmtoff; /* UTC offset in seconds */ 101 int tt_isdst; /* used to set tm_isdst */ 102 int tt_abbrind; /* abbreviation list index */ 103 int tt_ttisstd; /* TRUE if transition is std time */ 104 int tt_ttisgmt; /* TRUE if transition is UTC */ 105 }; 106 107 struct lsinfo { /* leap second information */ 108 time_t ls_trans; /* transition time */ 109 long ls_corr; /* correction to apply */ 110 }; 111 112 #define BIGGEST(a, b) (((a) > (b)) ? (a) : (b)) 113 114 #ifdef TZNAME_MAX 115 #define MY_TZNAME_MAX TZNAME_MAX 116 #endif /* defined TZNAME_MAX */ 117 #ifndef TZNAME_MAX 118 #define MY_TZNAME_MAX 255 119 #endif /* !defined TZNAME_MAX */ 120 121 struct state { 122 int leapcnt; 123 int timecnt; 124 int typecnt; 125 int charcnt; 126 int goback; 127 int goahead; 128 time_t ats[TZ_MAX_TIMES]; 129 unsigned char types[TZ_MAX_TIMES]; 130 struct ttinfo ttis[TZ_MAX_TYPES]; 131 char chars[BIGGEST(BIGGEST(TZ_MAX_CHARS + 1, sizeof gmt), 132 (2 * (MY_TZNAME_MAX + 1)))]; 133 struct lsinfo lsis[TZ_MAX_LEAPS]; 134 }; 135 136 struct rule { 137 int r_type; /* type of rule--see below */ 138 int r_day; /* day number of rule */ 139 int r_week; /* week number of rule */ 140 int r_mon; /* month number of rule */ 141 long r_time; /* transition time of rule */ 142 }; 143 144 #define JULIAN_DAY 0 /* Jn - Julian day */ 145 #define DAY_OF_YEAR 1 /* n - day of year */ 146 #define MONTH_NTH_DAY_OF_WEEK 2 /* Mm.n.d - month, week, day of week */ 147 148 /* 149 ** Prototypes for static functions. 150 */ 151 152 static long detzcode(const char * codep); 153 static time_t detzcode64(const char * codep); 154 static int differ_by_repeat(time_t t1, time_t t0); 155 static const char * getzname(const char * strp); 156 static const char * getqzname(const char * strp, const int delim); 157 static const char * getnum(const char * strp, int * nump, int min, 158 int max); 159 static const char * getsecs(const char * strp, long * secsp); 160 static const char * getoffset(const char * strp, long * offsetp); 161 static const char * getrule(const char * strp, struct rule * rulep); 162 static void gmtload(struct state * sp); 163 static struct tm * gmtsub(const time_t * timep, long offset, 164 struct tm * tmp); 165 static struct tm * localsub(const time_t * timep, long offset, 166 struct tm * tmp); 167 static int increment_overflow(int * number, int delta); 168 static int leaps_thru_end_of(int y); 169 static int long_increment_overflow(long * number, int delta); 170 static int long_normalize_overflow(long * tensptr, 171 int * unitsptr, int base); 172 static int normalize_overflow(int * tensptr, int * unitsptr, 173 int base); 174 static void settzname(void); 175 static time_t time1(struct tm * tmp, 176 struct tm * (*funcp)(const time_t *, 177 long, struct tm *), 178 long offset); 179 static time_t time2(struct tm *tmp, 180 struct tm * (*funcp)(const time_t *, 181 long, struct tm*), 182 long offset, int * okayp); 183 static time_t time2sub(struct tm *tmp, 184 struct tm * (*funcp)(const time_t *, 185 long, struct tm*), 186 long offset, int * okayp, int do_norm_secs); 187 static struct tm * timesub(const time_t * timep, long offset, 188 const struct state * sp, struct tm * tmp); 189 static int tmcomp(const struct tm * atmp, 190 const struct tm * btmp); 191 static time_t transtime(time_t janfirst, int year, 192 const struct rule * rulep, long offset); 193 static int typesequiv(const struct state * sp, int a, int b); 194 static int tzload(const char * name, struct state * sp, 195 int doextend); 196 static int tzparse(const char * name, struct state * sp, 197 int lastditch); 198 199 static struct state lclmem; 200 static struct state gmtmem; 201 #define lclptr (&lclmem) 202 #define gmtptr (&gmtmem) 203 204 #ifndef TZ_STRLEN_MAX 205 #define TZ_STRLEN_MAX 255 206 #endif /* !defined TZ_STRLEN_MAX */ 207 208 static char lcl_TZname[TZ_STRLEN_MAX + 1]; 209 static int lcl_is_set; 210 static int gmt_is_set; 211 static pthread_rwlock_t lcl_rwlock = PTHREAD_RWLOCK_INITIALIZER; 212 static pthread_mutex_t gmt_mutex = PTHREAD_MUTEX_INITIALIZER; 213 214 char * tzname[2] = { 215 wildabbr, 216 wildabbr 217 }; 218 219 /* 220 ** Section 4.12.3 of X3.159-1989 requires that 221 ** Except for the strftime function, these functions [asctime, 222 ** ctime, gmtime, localtime] return values in one of two static 223 ** objects: a broken-down time structure and an array of char. 224 ** Thanks to Paul Eggert for noting this. 225 */ 226 227 static struct tm tm; 228 229 time_t timezone = 0; 230 int daylight = 0; 231 232 static long 233 detzcode(const char * const codep) 234 { 235 long result; 236 int i; 237 238 result = (codep[0] & 0x80) ? ~0L : 0; 239 for (i = 0; i < 4; ++i) 240 result = (result << 8) | (codep[i] & 0xff); 241 return result; 242 } 243 244 static time_t 245 detzcode64(const char * const codep) 246 { 247 time_t result; 248 int i; 249 250 result = (codep[0] & 0x80) ? (~(int_fast64_t) 0) : 0; 251 for (i = 0; i < 8; ++i) 252 result = result * 256 + (codep[i] & 0xff); 253 return result; 254 } 255 256 static void 257 settzname(void) 258 { 259 struct state * const sp = lclptr; 260 int i; 261 262 tzname[0] = wildabbr; 263 tzname[1] = wildabbr; 264 daylight = 0; 265 timezone = 0; 266 267 for (i = 0; i < sp->typecnt; ++i) { 268 const struct ttinfo * const ttisp = &sp->ttis[i]; 269 270 tzname[ttisp->tt_isdst] = 271 &sp->chars[ttisp->tt_abbrind]; 272 if (ttisp->tt_isdst) 273 daylight = 1; 274 if (i == 0 || !ttisp->tt_isdst) 275 timezone = -(ttisp->tt_gmtoff); 276 } 277 /* 278 ** And to get the latest zone names into tzname. . . 279 */ 280 for (i = 0; i < sp->timecnt; ++i) { 281 const struct ttinfo * const ttisp = 282 &sp->ttis[ 283 sp->types[i]]; 284 285 tzname[ttisp->tt_isdst] = 286 &sp->chars[ttisp->tt_abbrind]; 287 } 288 /* 289 ** Finally, scrub the abbreviations. 290 ** First, replace bogus characters. 291 */ 292 for (i = 0; i < sp->charcnt; ++i) 293 if (strchr(TZ_ABBR_CHAR_SET, sp->chars[i]) == NULL) 294 sp->chars[i] = TZ_ABBR_ERR_CHAR; 295 /* 296 ** Second, truncate long abbreviations. 297 */ 298 for (i = 0; i < sp->typecnt; ++i) { 299 const struct ttinfo * const ttisp = &sp->ttis[i]; 300 char * cp = &sp->chars[ttisp->tt_abbrind]; 301 302 if (strlen(cp) > TZ_ABBR_MAX_LEN && 303 strcmp(cp, GRANDPARENTED) != 0) 304 *(cp + TZ_ABBR_MAX_LEN) = '\0'; 305 } 306 } 307 308 static int 309 differ_by_repeat(const time_t t1, const time_t t0) 310 { 311 if (TYPE_INTEGRAL(time_t) && 312 TYPE_BIT(time_t) - TYPE_SIGNED(time_t) < SECSPERREPEAT_BITS) 313 return 0; 314 return t1 - t0 == SECSPERREPEAT; 315 } 316 317 static int 318 tzload(const char *name, struct state * const sp, const int doextend) 319 { 320 const char * p; 321 int i; 322 int fid; 323 int stored; 324 int nread; 325 union { 326 struct tzhead tzhead; 327 char buf[2 * sizeof(struct tzhead) + 328 2 * sizeof *sp + 329 4 * TZ_MAX_TIMES]; 330 } u; 331 332 /* XXX The following is from OpenBSD, and I'm not sure it is correct */ 333 if (name != NULL && issetugid() != 0) 334 if ((name[0] == ':' && name[1] == '/') || 335 name[0] == '/' || strchr(name, '.')) 336 name = NULL; 337 if (name == NULL && (name = TZDEFAULT) == NULL) 338 return -1; 339 { 340 int doaccess; 341 struct stat stab; 342 /* 343 ** Section 4.9.1 of the C standard says that 344 ** "FILENAME_MAX expands to an integral constant expression 345 ** that is the size needed for an array of char large enough 346 ** to hold the longest file name string that the implementation 347 ** guarantees can be opened." 348 */ 349 char fullname[FILENAME_MAX + 1]; 350 351 if (name[0] == ':') 352 ++name; 353 doaccess = name[0] == '/'; 354 if (!doaccess) { 355 if ((p = TZDIR) == NULL) 356 return -1; 357 if ((strlen(p) + 1 + strlen(name) + 1) >= sizeof fullname) 358 return -1; 359 strcpy(fullname, p); 360 strcat(fullname, "/"); 361 strcat(fullname, name); 362 /* 363 ** Set doaccess if '.' (as in "../") shows up in name. 364 */ 365 if (strchr(name, '.') != NULL) 366 doaccess = TRUE; 367 name = fullname; 368 } 369 if (doaccess && access(name, R_OK) != 0) 370 return -1; 371 if ((fid = _open(name, O_RDONLY)) == -1) 372 return -1; 373 if ((_fstat(fid, &stab) < 0) || !S_ISREG(stab.st_mode)) { 374 _close(fid); 375 return -1; 376 } 377 } 378 nread = read(fid, u.buf, sizeof u.buf); 379 if (close(fid) < 0 || nread <= 0) 380 return -1; 381 for (stored = 4; stored <= 8; stored *= 2) { 382 int ttisstdcnt; 383 int ttisgmtcnt; 384 385 ttisstdcnt = (int) detzcode(u.tzhead.tzh_ttisstdcnt); 386 ttisgmtcnt = (int) detzcode(u.tzhead.tzh_ttisgmtcnt); 387 sp->leapcnt = (int) detzcode(u.tzhead.tzh_leapcnt); 388 sp->timecnt = (int) detzcode(u.tzhead.tzh_timecnt); 389 sp->typecnt = (int) detzcode(u.tzhead.tzh_typecnt); 390 sp->charcnt = (int) detzcode(u.tzhead.tzh_charcnt); 391 p = u.tzhead.tzh_charcnt + sizeof u.tzhead.tzh_charcnt; 392 if (sp->leapcnt < 0 || sp->leapcnt > TZ_MAX_LEAPS || 393 sp->typecnt <= 0 || sp->typecnt > TZ_MAX_TYPES || 394 sp->timecnt < 0 || sp->timecnt > TZ_MAX_TIMES || 395 sp->charcnt < 0 || sp->charcnt > TZ_MAX_CHARS || 396 (ttisstdcnt != sp->typecnt && ttisstdcnt != 0) || 397 (ttisgmtcnt != sp->typecnt && ttisgmtcnt != 0)) 398 return -1; 399 if (nread - (p - u.buf) < 400 sp->timecnt * stored + /* ats */ 401 sp->timecnt + /* types */ 402 sp->typecnt * 6 + /* ttinfos */ 403 sp->charcnt + /* chars */ 404 sp->leapcnt * (stored + 4) + /* lsinfos */ 405 ttisstdcnt + /* ttisstds */ 406 ttisgmtcnt) /* ttisgmts */ 407 return -1; 408 for (i = 0; i < sp->timecnt; ++i) { 409 sp->ats[i] = (stored == 4) ? 410 detzcode(p) : detzcode64(p); 411 p += stored; 412 } 413 for (i = 0; i < sp->timecnt; ++i) { 414 sp->types[i] = (unsigned char) *p++; 415 if (sp->types[i] >= sp->typecnt) 416 return -1; 417 } 418 for (i = 0; i < sp->typecnt; ++i) { 419 struct ttinfo * ttisp; 420 421 ttisp = &sp->ttis[i]; 422 ttisp->tt_gmtoff = detzcode(p); 423 p += 4; 424 ttisp->tt_isdst = (unsigned char) *p++; 425 if (ttisp->tt_isdst != 0 && ttisp->tt_isdst != 1) 426 return -1; 427 ttisp->tt_abbrind = (unsigned char) *p++; 428 if (ttisp->tt_abbrind < 0 || 429 ttisp->tt_abbrind > sp->charcnt) 430 return -1; 431 } 432 for (i = 0; i < sp->charcnt; ++i) 433 sp->chars[i] = *p++; 434 sp->chars[i] = '\0'; /* ensure '\0' at end */ 435 for (i = 0; i < sp->leapcnt; ++i) { 436 struct lsinfo * lsisp; 437 438 lsisp = &sp->lsis[i]; 439 lsisp->ls_trans = (stored == 4) ? 440 detzcode(p) : detzcode64(p); 441 p += stored; 442 lsisp->ls_corr = detzcode(p); 443 p += 4; 444 } 445 for (i = 0; i < sp->typecnt; ++i) { 446 struct ttinfo * ttisp; 447 448 ttisp = &sp->ttis[i]; 449 if (ttisstdcnt == 0) 450 ttisp->tt_ttisstd = FALSE; 451 else { 452 ttisp->tt_ttisstd = *p++; 453 if (ttisp->tt_ttisstd != TRUE && 454 ttisp->tt_ttisstd != FALSE) 455 return -1; 456 } 457 } 458 for (i = 0; i < sp->typecnt; ++i) { 459 struct ttinfo * ttisp; 460 461 ttisp = &sp->ttis[i]; 462 if (ttisgmtcnt == 0) 463 ttisp->tt_ttisgmt = FALSE; 464 else { 465 ttisp->tt_ttisgmt = *p++; 466 if (ttisp->tt_ttisgmt != TRUE && 467 ttisp->tt_ttisgmt != FALSE) 468 return -1; 469 } 470 } 471 /* 472 ** Out-of-sort ats should mean we're running on a 473 ** signed time_t system but using a data file with 474 ** unsigned values (or vice versa). 475 */ 476 for (i = 0; i < sp->timecnt - 2; ++i) 477 if (sp->ats[i] > sp->ats[i + 1]) { 478 ++i; 479 if (TYPE_SIGNED(time_t)) { 480 /* 481 ** Ignore the end (easy). 482 */ 483 sp->timecnt = i; 484 } else { 485 /* 486 ** Ignore the beginning (harder). 487 */ 488 int j; 489 490 for (j = 0; j + i < sp->timecnt; ++j) { 491 sp->ats[j] = sp->ats[j + i]; 492 sp->types[j] = sp->types[j + i]; 493 } 494 sp->timecnt = j; 495 } 496 break; 497 } 498 /* 499 ** If this is an old file, we're done. 500 */ 501 if (u.tzhead.tzh_version[0] == '\0') 502 break; 503 nread -= p - u.buf; 504 for (i = 0; i < nread; ++i) 505 u.buf[i] = p[i]; 506 /* 507 ** If this is a narrow integer time_t system, we're done. 508 */ 509 if (stored >= (int) sizeof(time_t) && TYPE_INTEGRAL(time_t)) 510 break; 511 } 512 if (doextend && nread > 2 && 513 u.buf[0] == '\n' && u.buf[nread - 1] == '\n' && 514 sp->typecnt + 2 <= TZ_MAX_TYPES) { 515 struct state ts; 516 int result; 517 518 u.buf[nread - 1] = '\0'; 519 result = tzparse(&u.buf[1], &ts, FALSE); 520 if (result == 0 && ts.typecnt == 2 && 521 sp->charcnt + ts.charcnt <= TZ_MAX_CHARS) { 522 for (i = 0; i < 2; ++i) 523 ts.ttis[i].tt_abbrind += 524 sp->charcnt; 525 for (i = 0; i < ts.charcnt; ++i) 526 sp->chars[sp->charcnt++] = 527 ts.chars[i]; 528 i = 0; 529 while (i < ts.timecnt && 530 ts.ats[i] <= 531 sp->ats[sp->timecnt - 1]) 532 ++i; 533 while (i < ts.timecnt && 534 sp->timecnt < TZ_MAX_TIMES) { 535 sp->ats[sp->timecnt] = 536 ts.ats[i]; 537 sp->types[sp->timecnt] = 538 sp->typecnt + 539 ts.types[i]; 540 ++sp->timecnt; 541 ++i; 542 } 543 sp->ttis[sp->typecnt++] = ts.ttis[0]; 544 sp->ttis[sp->typecnt++] = ts.ttis[1]; 545 } 546 } 547 sp->goback = sp->goahead = FALSE; 548 if (sp->timecnt > 1) { 549 for (i = 1; i < sp->timecnt; ++i) 550 if (typesequiv(sp, sp->types[i], sp->types[0]) && 551 differ_by_repeat(sp->ats[i], sp->ats[0])) { 552 sp->goback = TRUE; 553 break; 554 } 555 for (i = sp->timecnt - 2; i >= 0; --i) 556 if (typesequiv(sp, sp->types[sp->timecnt - 1], 557 sp->types[i]) && 558 differ_by_repeat(sp->ats[sp->timecnt - 1], 559 sp->ats[i])) { 560 sp->goahead = TRUE; 561 break; 562 } 563 } 564 return 0; 565 } 566 567 static int 568 typesequiv(const struct state * const sp, const int a, const int b) 569 { 570 int result; 571 572 if (sp == NULL || 573 a < 0 || a >= sp->typecnt || 574 b < 0 || b >= sp->typecnt) 575 result = FALSE; 576 else { 577 const struct ttinfo * ap = &sp->ttis[a]; 578 const struct ttinfo * bp = &sp->ttis[b]; 579 result = ap->tt_gmtoff == bp->tt_gmtoff && 580 ap->tt_isdst == bp->tt_isdst && 581 ap->tt_ttisstd == bp->tt_ttisstd && 582 ap->tt_ttisgmt == bp->tt_ttisgmt && 583 strcmp(&sp->chars[ap->tt_abbrind], 584 &sp->chars[bp->tt_abbrind]) == 0; 585 } 586 return result; 587 } 588 589 static const int mon_lengths[2][MONSPERYEAR] = { 590 { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }, 591 { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 } 592 }; 593 594 static const int year_lengths[2] = { 595 DAYSPERNYEAR, DAYSPERLYEAR 596 }; 597 598 /* 599 ** Given a pointer into a time zone string, scan until a character that is not 600 ** a valid character in a zone name is found. Return a pointer to that 601 ** character. 602 */ 603 604 static const char * 605 getzname(const char *strp) 606 { 607 char c; 608 609 while ((c = *strp) != '\0' && !is_digit(c) && c != ',' && c != '-' && 610 c != '+') 611 ++strp; 612 return strp; 613 } 614 615 /* 616 ** Given a pointer into an extended time zone string, scan until the ending 617 ** delimiter of the zone name is located. Return a pointer to the delimiter. 618 ** 619 ** As with getzname above, the legal character set is actually quite 620 ** restricted, with other characters producing undefined results. 621 ** We don't do any checking here; checking is done later in common-case code. 622 */ 623 624 static const char * 625 getqzname(const char *strp, const int delim) 626 { 627 int c; 628 629 while ((c = *strp) != '\0' && c != delim) 630 ++strp; 631 return strp; 632 } 633 634 /* 635 ** Given a pointer into a time zone string, extract a number from that string. 636 ** Check that the number is within a specified range; if it is not, return 637 ** NULL. 638 ** Otherwise, return a pointer to the first character not part of the number. 639 */ 640 641 static const char * 642 getnum(const char *strp, int * const nump, const int min, const int max) 643 { 644 char c; 645 int num; 646 647 if (strp == NULL || !is_digit(c = *strp)) 648 return NULL; 649 num = 0; 650 do { 651 num = num * 10 + (c - '0'); 652 if (num > max) 653 return NULL; /* illegal value */ 654 c = *++strp; 655 } while (is_digit(c)); 656 if (num < min) 657 return NULL; /* illegal value */ 658 *nump = num; 659 return strp; 660 } 661 662 /* 663 ** Given a pointer into a time zone string, extract a number of seconds, 664 ** in hh[:mm[:ss]] form, from the string. 665 ** If any error occurs, return NULL. 666 ** Otherwise, return a pointer to the first character not part of the number 667 ** of seconds. 668 */ 669 670 static const char * 671 getsecs(const char *strp, long * const secsp) 672 { 673 int num; 674 675 /* 676 ** `HOURSPERDAY * DAYSPERWEEK - 1' allows quasi-Posix rules like 677 ** "M10.4.6/26", which does not conform to Posix, 678 ** but which specifies the equivalent of 679 ** ``02:00 on the first Sunday on or after 23 Oct''. 680 */ 681 strp = getnum(strp, &num, 0, HOURSPERDAY * DAYSPERWEEK - 1); 682 if (strp == NULL) 683 return NULL; 684 *secsp = num * (long) SECSPERHOUR; 685 if (*strp == ':') { 686 ++strp; 687 strp = getnum(strp, &num, 0, MINSPERHOUR - 1); 688 if (strp == NULL) 689 return NULL; 690 *secsp += num * SECSPERMIN; 691 if (*strp == ':') { 692 ++strp; 693 /* `SECSPERMIN' allows for leap seconds. */ 694 strp = getnum(strp, &num, 0, SECSPERMIN); 695 if (strp == NULL) 696 return NULL; 697 *secsp += num; 698 } 699 } 700 return strp; 701 } 702 703 /* 704 ** Given a pointer into a time zone string, extract an offset, in 705 ** [+-]hh[:mm[:ss]] form, from the string. 706 ** If any error occurs, return NULL. 707 ** Otherwise, return a pointer to the first character not part of the time. 708 */ 709 710 static const char * 711 getoffset(const char *strp, long * const offsetp) 712 { 713 int neg = 0; 714 715 if (*strp == '-') { 716 neg = 1; 717 ++strp; 718 } else if (*strp == '+') 719 ++strp; 720 strp = getsecs(strp, offsetp); 721 if (strp == NULL) 722 return NULL; /* illegal time */ 723 if (neg) 724 *offsetp = -*offsetp; 725 return strp; 726 } 727 728 /* 729 ** Given a pointer into a time zone string, extract a rule in the form 730 ** date[/time]. See POSIX section 8 for the format of "date" and "time". 731 ** If a valid rule is not found, return NULL. 732 ** Otherwise, return a pointer to the first character not part of the rule. 733 */ 734 735 static const char * 736 getrule(const char *strp, struct rule * const rulep) 737 { 738 if (*strp == 'J') { 739 /* 740 ** Julian day. 741 */ 742 rulep->r_type = JULIAN_DAY; 743 ++strp; 744 strp = getnum(strp, &rulep->r_day, 1, DAYSPERNYEAR); 745 } else if (*strp == 'M') { 746 /* 747 ** Month, week, day. 748 */ 749 rulep->r_type = MONTH_NTH_DAY_OF_WEEK; 750 ++strp; 751 strp = getnum(strp, &rulep->r_mon, 1, MONSPERYEAR); 752 if (strp == NULL) 753 return NULL; 754 if (*strp++ != '.') 755 return NULL; 756 strp = getnum(strp, &rulep->r_week, 1, 5); 757 if (strp == NULL) 758 return NULL; 759 if (*strp++ != '.') 760 return NULL; 761 strp = getnum(strp, &rulep->r_day, 0, DAYSPERWEEK - 1); 762 } else if (is_digit(*strp)) { 763 /* 764 ** Day of year. 765 */ 766 rulep->r_type = DAY_OF_YEAR; 767 strp = getnum(strp, &rulep->r_day, 0, DAYSPERLYEAR - 1); 768 } else return NULL; /* invalid format */ 769 if (strp == NULL) 770 return NULL; 771 if (*strp == '/') { 772 /* 773 ** Time specified. 774 */ 775 ++strp; 776 strp = getsecs(strp, &rulep->r_time); 777 } else rulep->r_time = 2 * SECSPERHOUR; /* default = 2:00:00 */ 778 return strp; 779 } 780 781 /* 782 ** Given the Epoch-relative time of January 1, 00:00:00 UTC, in a year, the 783 ** year, a rule, and the offset from UTC at the time that rule takes effect, 784 ** calculate the Epoch-relative time that rule takes effect. 785 */ 786 787 static time_t 788 transtime(const time_t janfirst, const int year, 789 const struct rule * const rulep, const long offset) 790 { 791 int leapyear; 792 time_t value; 793 int i; 794 int d, m1, yy0, yy1, yy2, dow; 795 796 INITIALIZE(value); 797 leapyear = isleap(year); 798 switch (rulep->r_type) { 799 800 case JULIAN_DAY: 801 /* 802 ** Jn - Julian day, 1 == January 1, 60 == March 1 even in leap 803 ** years. 804 ** In non-leap years, or if the day number is 59 or less, just 805 ** add SECSPERDAY times the day number-1 to the time of 806 ** January 1, midnight, to get the day. 807 */ 808 value = janfirst + (rulep->r_day - 1) * SECSPERDAY; 809 if (leapyear && rulep->r_day >= 60) 810 value += SECSPERDAY; 811 break; 812 813 case DAY_OF_YEAR: 814 /* 815 ** n - day of year. 816 ** Just add SECSPERDAY times the day number to the time of 817 ** January 1, midnight, to get the day. 818 */ 819 value = janfirst + rulep->r_day * SECSPERDAY; 820 break; 821 822 case MONTH_NTH_DAY_OF_WEEK: 823 /* 824 ** Mm.n.d - nth "dth day" of month m. 825 */ 826 value = janfirst; 827 for (i = 0; i < rulep->r_mon - 1; ++i) 828 value += mon_lengths[leapyear][i] * SECSPERDAY; 829 830 /* 831 ** Use Zeller's Congruence to get day-of-week of first day of 832 ** month. 833 */ 834 m1 = (rulep->r_mon + 9) % 12 + 1; 835 yy0 = (rulep->r_mon <= 2) ? (year - 1) : year; 836 yy1 = yy0 / 100; 837 yy2 = yy0 % 100; 838 dow = ((26 * m1 - 2) / 10 + 839 1 + yy2 + yy2 / 4 + yy1 / 4 - 2 * yy1) % 7; 840 if (dow < 0) 841 dow += DAYSPERWEEK; 842 843 /* 844 ** "dow" is the day-of-week of the first day of the month. Get 845 ** the day-of-month (zero-origin) of the first "dow" day of the 846 ** month. 847 */ 848 d = rulep->r_day - dow; 849 if (d < 0) 850 d += DAYSPERWEEK; 851 for (i = 1; i < rulep->r_week; ++i) { 852 if (d + DAYSPERWEEK >= 853 mon_lengths[leapyear][rulep->r_mon - 1]) 854 break; 855 d += DAYSPERWEEK; 856 } 857 858 /* 859 ** "d" is the day-of-month (zero-origin) of the day we want. 860 */ 861 value += d * SECSPERDAY; 862 break; 863 } 864 865 /* 866 ** "value" is the Epoch-relative time of 00:00:00 UTC on the day in 867 ** question. To get the Epoch-relative time of the specified local 868 ** time on that day, add the transition time and the current offset 869 ** from UTC. 870 */ 871 return value + rulep->r_time + offset; 872 } 873 874 /* 875 ** Given a POSIX section 8-style TZ string, fill in the rule tables as 876 ** appropriate. 877 */ 878 879 static int 880 tzparse(const char *name, struct state * const sp, const int lastditch) 881 { 882 const char * stdname; 883 const char * dstname; 884 size_t stdlen; 885 size_t dstlen; 886 long stdoffset; 887 long dstoffset; 888 time_t * atp; 889 unsigned char * typep; 890 char * cp; 891 int load_result; 892 893 INITIALIZE(dstname); 894 stdname = name; 895 if (lastditch) { 896 stdlen = strlen(name); /* length of standard zone name */ 897 name += stdlen; 898 if (stdlen >= sizeof sp->chars) 899 stdlen = (sizeof sp->chars) - 1; 900 stdoffset = 0; 901 } else { 902 if (*name == '<') { 903 name++; 904 stdname = name; 905 name = getqzname(name, '>'); 906 if (*name != '>') 907 return (-1); 908 stdlen = name - stdname; 909 name++; 910 } else { 911 name = getzname(name); 912 stdlen = name - stdname; 913 } 914 if (*name == '\0') 915 return -1; 916 name = getoffset(name, &stdoffset); 917 if (name == NULL) 918 return -1; 919 } 920 load_result = tzload(TZDEFRULES, sp, FALSE); 921 if (load_result != 0) 922 sp->leapcnt = 0; /* so, we're off a little */ 923 if (*name != '\0') { 924 if (*name == '<') { 925 dstname = ++name; 926 name = getqzname(name, '>'); 927 if (*name != '>') 928 return -1; 929 dstlen = name - dstname; 930 name++; 931 } else { 932 dstname = name; 933 name = getzname(name); 934 dstlen = name - dstname; /* length of DST zone name */ 935 } 936 if (*name != '\0' && *name != ',' && *name != ';') { 937 name = getoffset(name, &dstoffset); 938 if (name == NULL) 939 return -1; 940 } else dstoffset = stdoffset - SECSPERHOUR; 941 if (*name == '\0' && load_result != 0) 942 name = TZDEFRULESTRING; 943 if (*name == ',' || *name == ';') { 944 struct rule start; 945 struct rule end; 946 int year; 947 time_t janfirst; 948 time_t starttime; 949 time_t endtime; 950 951 ++name; 952 if ((name = getrule(name, &start)) == NULL) 953 return -1; 954 if (*name++ != ',') 955 return -1; 956 if ((name = getrule(name, &end)) == NULL) 957 return -1; 958 if (*name != '\0') 959 return -1; 960 sp->typecnt = 2; /* standard time and DST */ 961 /* 962 ** Two transitions per year, from EPOCH_YEAR forward. 963 */ 964 sp->ttis[0].tt_gmtoff = -dstoffset; 965 sp->ttis[0].tt_isdst = 1; 966 sp->ttis[0].tt_abbrind = stdlen + 1; 967 sp->ttis[1].tt_gmtoff = -stdoffset; 968 sp->ttis[1].tt_isdst = 0; 969 sp->ttis[1].tt_abbrind = 0; 970 atp = sp->ats; 971 typep = sp->types; 972 janfirst = 0; 973 sp->timecnt = 0; 974 for (year = EPOCH_YEAR; 975 sp->timecnt + 2 <= TZ_MAX_TIMES; 976 ++year) { 977 time_t newfirst; 978 979 starttime = transtime(janfirst, year, &start, 980 stdoffset); 981 endtime = transtime(janfirst, year, &end, 982 dstoffset); 983 if (starttime > endtime) { 984 *atp++ = endtime; 985 *typep++ = 1; /* DST ends */ 986 *atp++ = starttime; 987 *typep++ = 0; /* DST begins */ 988 } else { 989 *atp++ = starttime; 990 *typep++ = 0; /* DST begins */ 991 *atp++ = endtime; 992 *typep++ = 1; /* DST ends */ 993 } 994 sp->timecnt += 2; 995 newfirst = janfirst; 996 newfirst += year_lengths[isleap(year)] * 997 SECSPERDAY; 998 if (newfirst <= janfirst) 999 break; 1000 janfirst = newfirst; 1001 } 1002 } else { 1003 long theirstdoffset; 1004 long theirdstoffset; 1005 long theiroffset; 1006 int isdst; 1007 int i; 1008 int j; 1009 1010 if (*name != '\0') 1011 return -1; 1012 /* 1013 ** Initial values of theirstdoffset and theirdstoffset. 1014 */ 1015 theirstdoffset = 0; 1016 for (i = 0; i < sp->timecnt; ++i) { 1017 j = sp->types[i]; 1018 if (!sp->ttis[j].tt_isdst) { 1019 theirstdoffset = 1020 -sp->ttis[j].tt_gmtoff; 1021 break; 1022 } 1023 } 1024 theirdstoffset = 0; 1025 for (i = 0; i < sp->timecnt; ++i) { 1026 j = sp->types[i]; 1027 if (sp->ttis[j].tt_isdst) { 1028 theirdstoffset = 1029 -sp->ttis[j].tt_gmtoff; 1030 break; 1031 } 1032 } 1033 /* 1034 ** Initially we're assumed to be in standard time. 1035 */ 1036 isdst = FALSE; 1037 theiroffset = theirstdoffset; 1038 /* 1039 ** Now juggle transition times and types 1040 ** tracking offsets as you do. 1041 */ 1042 for (i = 0; i < sp->timecnt; ++i) { 1043 j = sp->types[i]; 1044 sp->types[i] = sp->ttis[j].tt_isdst; 1045 if (sp->ttis[j].tt_ttisgmt) { 1046 /* No adjustment to transition time */ 1047 } else { 1048 /* 1049 ** If summer time is in effect, and the 1050 ** transition time was not specified as 1051 ** standard time, add the summer time 1052 ** offset to the transition time; 1053 ** otherwise, add the standard time 1054 ** offset to the transition time. 1055 */ 1056 /* 1057 ** Transitions from DST to DDST 1058 ** will effectively disappear since 1059 ** POSIX provides for only one DST 1060 ** offset. 1061 */ 1062 if (isdst && !sp->ttis[j].tt_ttisstd) { 1063 sp->ats[i] += dstoffset - 1064 theirdstoffset; 1065 } else { 1066 sp->ats[i] += stdoffset - 1067 theirstdoffset; 1068 } 1069 } 1070 theiroffset = -sp->ttis[j].tt_gmtoff; 1071 if (sp->ttis[j].tt_isdst) 1072 theirdstoffset = theiroffset; 1073 else theirstdoffset = theiroffset; 1074 } 1075 /* 1076 ** Finally, fill in ttis. 1077 ** ttisstd and ttisgmt need not be handled. 1078 */ 1079 sp->ttis[0].tt_gmtoff = -stdoffset; 1080 sp->ttis[0].tt_isdst = FALSE; 1081 sp->ttis[0].tt_abbrind = 0; 1082 sp->ttis[1].tt_gmtoff = -dstoffset; 1083 sp->ttis[1].tt_isdst = TRUE; 1084 sp->ttis[1].tt_abbrind = stdlen + 1; 1085 sp->typecnt = 2; 1086 } 1087 } else { 1088 dstlen = 0; 1089 sp->typecnt = 1; /* only standard time */ 1090 sp->timecnt = 0; 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->tm_isdst > 1) 1868 tmp->tm_isdst = 1; 1869 t = time2(tmp, funcp, offset, &okay); 1870 1871 /* 1872 ** PCTS code courtesy Grant Sullivan. 1873 */ 1874 if (okay) 1875 return t; 1876 if (tmp->tm_isdst < 0) 1877 tmp->tm_isdst = 0; /* reset to std and try again */ 1878 1879 /* 1880 ** We're supposed to assume that somebody took a time of one type 1881 ** and did some math on it that yielded a "struct tm" that's bad. 1882 ** We try to divine the type they started from and adjust to the 1883 ** type they need. 1884 */ 1885 sp = (const struct state *) ((funcp == localsub) ? lclptr : gmtptr); 1886 1887 for (i = 0; i < sp->typecnt; ++i) 1888 seen[i] = FALSE; 1889 nseen = 0; 1890 for (i = sp->timecnt - 1; i >= 0; --i) 1891 if (!seen[sp->types[i]]) { 1892 seen[sp->types[i]] = TRUE; 1893 types[nseen++] = sp->types[i]; 1894 } 1895 for (sameind = 0; sameind < nseen; ++sameind) { 1896 samei = types[sameind]; 1897 if (sp->ttis[samei].tt_isdst != tmp->tm_isdst) 1898 continue; 1899 for (otherind = 0; otherind < nseen; ++otherind) { 1900 otheri = types[otherind]; 1901 if (sp->ttis[otheri].tt_isdst == tmp->tm_isdst) 1902 continue; 1903 tmp->tm_sec += sp->ttis[otheri].tt_gmtoff - 1904 sp->ttis[samei].tt_gmtoff; 1905 tmp->tm_isdst = !tmp->tm_isdst; 1906 t = time2(tmp, funcp, offset, &okay); 1907 if (okay) 1908 return t; 1909 tmp->tm_sec -= sp->ttis[otheri].tt_gmtoff - 1910 sp->ttis[samei].tt_gmtoff; 1911 tmp->tm_isdst = !tmp->tm_isdst; 1912 } 1913 } 1914 return WRONG; 1915 } 1916 1917 time_t 1918 mktime(struct tm * const tmp) 1919 { 1920 time_t mktime_return_value; 1921 _RWLOCK_RDLOCK(&lcl_rwlock); 1922 tzset_basic(1); 1923 mktime_return_value = time1(tmp, localsub, 0L); 1924 _RWLOCK_UNLOCK(&lcl_rwlock); 1925 return(mktime_return_value); 1926 } 1927 1928 time_t 1929 timelocal(struct tm * const tmp) 1930 { 1931 tmp->tm_isdst = -1; /* in case it wasn't initialized */ 1932 return mktime(tmp); 1933 } 1934 1935 time_t 1936 timegm(struct tm * const tmp) 1937 { 1938 tmp->tm_isdst = 0; 1939 return time1(tmp, gmtsub, 0L); 1940 } 1941 1942 time_t 1943 timeoff(struct tm * const tmp, const long offset) 1944 { 1945 tmp->tm_isdst = 0; 1946 return time1(tmp, gmtsub, offset); 1947 } 1948 1949 #ifdef CMUCS 1950 1951 /* 1952 ** The following is supplied for compatibility with 1953 ** previous versions of the CMUCS runtime library. 1954 */ 1955 1956 long 1957 gtime(struct tm * const tmp) 1958 { 1959 const time_t t = mktime(tmp); 1960 1961 if (t == WRONG) 1962 return -1; 1963 return t; 1964 } 1965 1966 #endif /* defined CMUCS */ 1967 1968 /* 1969 ** XXX--is the below the right way to conditionalize?? 1970 */ 1971 1972 /* 1973 ** IEEE Std 1003.1-1988 (POSIX) legislates that 536457599 1974 ** shall correspond to "Wed Dec 31 23:59:59 UTC 1986", which 1975 ** is not the case if we are accounting for leap seconds. 1976 ** So, we provide the following conversion routines for use 1977 ** when exchanging timestamps with POSIX conforming systems. 1978 */ 1979 1980 static long 1981 leapcorr(time_t *timep) 1982 { 1983 struct state * sp; 1984 struct lsinfo * lp; 1985 int i; 1986 1987 sp = lclptr; 1988 i = sp->leapcnt; 1989 while (--i >= 0) { 1990 lp = &sp->lsis[i]; 1991 if (*timep >= lp->ls_trans) 1992 return lp->ls_corr; 1993 } 1994 return 0; 1995 } 1996 1997 time_t 1998 time2posix(time_t t) 1999 { 2000 tzset(); 2001 return t - leapcorr(&t); 2002 } 2003 2004 time_t 2005 posix2time(time_t t) 2006 { 2007 time_t x; 2008 time_t y; 2009 2010 tzset(); 2011 /* 2012 ** For a positive leap second hit, the result 2013 ** is not unique. For a negative leap second 2014 ** hit, the corresponding time doesn't exist, 2015 ** so we return an adjacent second. 2016 */ 2017 x = t + leapcorr(&t); 2018 y = x - leapcorr(&x); 2019 if (y < t) { 2020 do { 2021 x++; 2022 y = x - leapcorr(&x); 2023 } while (y < t); 2024 if (t != y) 2025 return x - 1; 2026 } else 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 } 2034 return x; 2035 } 2036