1/* $OpenBSD: localtime.c,v 1.66 2024/04/04 02:20:01 millert Exp $ */ 2/* 3** This file is in the public domain, so clarified as of 4** 1996-06-05 by Arthur David Olson. 5*/ 6 7/* 8** Leap second handling from Bradley White. 9** POSIX-style TZ environment variable handling from Guy Harris. 10*/ 11 12#include <ctype.h> 13#include <errno.h> 14#include <fcntl.h> 15#include <stdint.h> 16#include <stdlib.h> 17#include <string.h> 18#include <unistd.h> 19 20#include "private.h" 21#include "tzfile.h" 22#include "thread_private.h" 23 24#ifndef TZ_ABBR_MAX_LEN 25#define TZ_ABBR_MAX_LEN 16 26#endif /* !defined TZ_ABBR_MAX_LEN */ 27 28#ifndef TZ_ABBR_CHAR_SET 29#define TZ_ABBR_CHAR_SET \ 30 "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789 :+-._" 31#endif /* !defined TZ_ABBR_CHAR_SET */ 32 33#ifndef TZ_ABBR_ERR_CHAR 34#define TZ_ABBR_ERR_CHAR '_' 35#endif /* !defined TZ_ABBR_ERR_CHAR */ 36 37#ifndef WILDABBR 38/* 39** Someone might make incorrect use of a time zone abbreviation: 40** 1. They might reference tzname[0] before calling tzset (explicitly 41** or implicitly). 42** 2. They might reference tzname[1] before calling tzset (explicitly 43** or implicitly). 44** 3. They might reference tzname[1] after setting to a time zone 45** in which Daylight Saving Time is never observed. 46** 4. They might reference tzname[0] after setting to a time zone 47** in which Standard Time is never observed. 48** 5. They might reference tm.tm_zone after calling offtime. 49** What's best to do in the above cases is open to debate; 50** for now, we just set things up so that in any of the five cases 51** WILDABBR is used. Another possibility: initialize tzname[0] to the 52** string "tzname[0] used before set", and similarly for the other cases. 53** And another: initialize tzname[0] to "ERA", with an explanation in the 54** manual page of what this "time zone abbreviation" means (doing this so 55** that tzname[0] has the "normal" length of three characters). 56*/ 57#define WILDABBR " " 58#endif /* !defined WILDABBR */ 59 60static char wildabbr[] = WILDABBR; 61 62static const char gmt[] = "GMT"; 63 64/* 65** The DST rules to use if TZ has no rules and we can't load TZDEFRULES. 66** We default to US rules as of 1999-08-17. 67** POSIX 1003.1 section 8.1.1 says that the default DST rules are 68** implementation dependent; for historical reasons, US rules are a 69** common default. 70*/ 71#ifndef TZDEFRULESTRING 72#define TZDEFRULESTRING ",M4.1.0,M10.5.0" 73#endif /* !defined TZDEFDST */ 74 75struct ttinfo { /* time type information */ 76 long tt_gmtoff; /* UTC offset in seconds */ 77 int tt_isdst; /* used to set tm_isdst */ 78 int tt_abbrind; /* abbreviation list index */ 79 int tt_ttisstd; /* TRUE if transition is std time */ 80 int tt_ttisgmt; /* TRUE if transition is UTC */ 81}; 82 83struct lsinfo { /* leap second information */ 84 time_t ls_trans; /* transition time */ 85 long ls_corr; /* correction to apply */ 86}; 87 88#define BIGGEST(a, b) (((a) > (b)) ? (a) : (b)) 89 90#ifdef TZNAME_MAX 91#define MY_TZNAME_MAX TZNAME_MAX 92#endif /* defined TZNAME_MAX */ 93#ifndef TZNAME_MAX 94#define MY_TZNAME_MAX 255 95#endif /* !defined TZNAME_MAX */ 96 97struct state { 98 int leapcnt; 99 int timecnt; 100 int typecnt; 101 int charcnt; 102 int goback; 103 int goahead; 104 time_t ats[TZ_MAX_TIMES]; 105 unsigned char types[TZ_MAX_TIMES]; 106 struct ttinfo ttis[TZ_MAX_TYPES]; 107 char chars[BIGGEST(BIGGEST(TZ_MAX_CHARS + 1, sizeof gmt), 108 (2 * (MY_TZNAME_MAX + 1)))]; 109 struct lsinfo lsis[TZ_MAX_LEAPS]; 110}; 111 112struct rule { 113 int r_type; /* type of rule--see below */ 114 int r_day; /* day number of rule */ 115 int r_week; /* week number of rule */ 116 int r_mon; /* month number of rule */ 117 long r_time; /* transition time of rule */ 118}; 119 120#define JULIAN_DAY 0 /* Jn - Julian day */ 121#define DAY_OF_YEAR 1 /* n - day of year */ 122#define MONTH_NTH_DAY_OF_WEEK 2 /* Mm.n.d - month, week, day of week */ 123 124/* 125** Prototypes for static functions. 126*/ 127 128static long detzcode(const char * codep); 129static time_t detzcode64(const char * codep); 130static int differ_by_repeat(time_t t1, time_t t0); 131static const char * getzname(const char * strp); 132static const char * getqzname(const char * strp, const int delim); 133static const char * getnum(const char * strp, int * nump, int min, 134 int max); 135static const char * getsecs(const char * strp, long * secsp); 136static const char * getoffset(const char * strp, long * offsetp); 137static const char * getrule(const char * strp, struct rule * rulep); 138static void gmtload(struct state * sp); 139static struct tm * gmtsub(const time_t * timep, long offset, 140 struct tm * tmp); 141static struct tm * localsub(const time_t * timep, long offset, 142 struct tm * tmp); 143static int increment_overflow(int * number, int delta); 144static int leaps_thru_end_of(int y); 145static int long_increment_overflow(long * number, int delta); 146static int long_normalize_overflow(long * tensptr, 147 int * unitsptr, int base); 148static int normalize_overflow(int * tensptr, int * unitsptr, 149 int base); 150static void settzname(void); 151static time_t time1(struct tm * tmp, 152 struct tm * (*funcp)(const time_t *, 153 long, struct tm *), 154 long offset); 155static time_t time2(struct tm *tmp, 156 struct tm * (*funcp)(const time_t *, 157 long, struct tm*), 158 long offset, int * okayp); 159static time_t time2sub(struct tm *tmp, 160 struct tm * (*funcp)(const time_t *, 161 long, struct tm*), 162 long offset, int * okayp, int do_norm_secs); 163static struct tm * timesub(const time_t * timep, long offset, 164 const struct state * sp, struct tm * tmp); 165static int tmcomp(const struct tm * atmp, 166 const struct tm * btmp); 167static time_t transtime(time_t janfirst, int year, 168 const struct rule * rulep, long offset); 169static int typesequiv(const struct state * sp, int a, int b); 170static int tzload(const char * name, struct state * sp, 171 int doextend); 172static int tzparse(const char * name, struct state * sp, 173 int lastditch); 174 175#ifdef STD_INSPIRED 176struct tm *offtime(const time_t *, long); 177time_t time2posix(time_t); 178time_t posix2time(time_t); 179PROTO_DEPRECATED(offtime); 180PROTO_DEPRECATED(time2posix); 181PROTO_DEPRECATED(posix2time); 182#endif 183 184static struct state * lclptr; 185static struct state * gmtptr; 186 187 188#ifndef TZ_STRLEN_MAX 189#define TZ_STRLEN_MAX 255 190#endif /* !defined TZ_STRLEN_MAX */ 191 192static int lcl_is_set; 193static int gmt_is_set; 194_THREAD_PRIVATE_MUTEX(lcl); 195_THREAD_PRIVATE_MUTEX(gmt); 196 197char * tzname[2] = { 198 wildabbr, 199 wildabbr 200}; 201#if 0 202DEF_WEAK(tzname); 203#endif 204 205/* 206** Section 4.12.3 of X3.159-1989 requires that 207** Except for the strftime function, these functions [asctime, 208** ctime, gmtime, localtime] return values in one of two static 209** objects: a broken-down time structure and an array of char. 210** Thanks to Paul Eggert for noting this. 211*/ 212 213static struct tm tm; 214 215long timezone = 0; 216int daylight = 0; 217 218static long 219detzcode(const char *codep) 220{ 221 long result; 222 int i; 223 224 result = (codep[0] & 0x80) ? ~0L : 0; 225 for (i = 0; i < 4; ++i) 226 result = (result << 8) | (codep[i] & 0xff); 227 return result; 228} 229 230static time_t 231detzcode64(const char *codep) 232{ 233 time_t result; 234 int i; 235 236 result = (codep[0] & 0x80) ? (~(int_fast64_t) 0) : 0; 237 for (i = 0; i < 8; ++i) 238 result = result * 256 + (codep[i] & 0xff); 239 return result; 240} 241 242static void 243settzname(void) 244{ 245 struct state * const sp = lclptr; 246 int i; 247 248 tzname[0] = wildabbr; 249 tzname[1] = wildabbr; 250 daylight = 0; 251 timezone = 0; 252 if (sp == NULL) { 253 tzname[0] = tzname[1] = (char *)gmt; 254 return; 255 } 256 /* 257 ** And to get the latest zone names into tzname. . . 258 */ 259 for (i = 0; i < sp->timecnt; ++i) { 260 const struct ttinfo *ttisp = &sp->ttis[sp->types[i]]; 261 262 tzname[ttisp->tt_isdst] = &sp->chars[ttisp->tt_abbrind]; 263 if (ttisp->tt_isdst) 264 daylight = 1; 265 if (!ttisp->tt_isdst) 266 timezone = -(ttisp->tt_gmtoff); 267 } 268 /* 269 ** Finally, scrub the abbreviations. 270 ** First, replace bogus characters. 271 */ 272 for (i = 0; i < sp->charcnt; ++i) { 273 if (strchr(TZ_ABBR_CHAR_SET, sp->chars[i]) == NULL) 274 sp->chars[i] = TZ_ABBR_ERR_CHAR; 275 } 276 /* 277 ** Second, truncate long abbreviations. 278 */ 279 for (i = 0; i < sp->typecnt; ++i) { 280 const struct ttinfo *ttisp = &sp->ttis[i]; 281 char *cp = &sp->chars[ttisp->tt_abbrind]; 282 283 if (strlen(cp) > TZ_ABBR_MAX_LEN && 284 strcmp(cp, GRANDPARENTED) != 0) 285 *(cp + TZ_ABBR_MAX_LEN) = '\0'; 286 } 287} 288 289static int 290differ_by_repeat(time_t t1, time_t t0) 291{ 292 if (TYPE_BIT(time_t) - 1 < SECSPERREPEAT_BITS) 293 return 0; 294 return (int64_t)t1 - t0 == SECSPERREPEAT; 295} 296 297static int 298tzpath_ok(const char *name) 299{ 300 /* Reject absolute paths that don't start with TZDIR. */ 301 if (name[0] == '/' && (strncmp(name, TZDIR, sizeof(TZDIR) - 1) != 0 || 302 name[sizeof(TZDIR) - 1] != '/')) 303 return 0; 304 305 /* Reject paths that contain "../". */ 306 if (strstr(name, "../") != NULL) 307 return 0; 308 309 return 1; 310} 311 312static int 313open_tzfile(const char *name) 314{ 315 char fullname[PATH_MAX]; 316 int i; 317 318 if (name != NULL) { 319 /* 320 * POSIX section 8 says that names starting with a ':' are 321 * "implementation-defined". We treat them as timezone paths. 322 */ 323 if (name[0] == ':') 324 name++; 325 326 /* 327 * Ignore absolute paths that don't start with TZDIR 328 * or that contain "../". 329 */ 330 if (!tzpath_ok(name)) 331 name = NULL; 332 } 333 334 if (name == NULL) { 335 name = TZDEFAULT; 336 } else if (name[0] != '/') { 337 /* Time zone data path is relative to TZDIR. */ 338 i = snprintf(fullname, sizeof(fullname), "%s/%s", TZDIR, name); 339 if (i < 0 || i >= sizeof(fullname)) { 340 errno = ENAMETOOLONG; 341 return -1; 342 } 343 name = fullname; 344 } 345 346 return open(name, O_RDONLY); 347} 348 349static int 350tzload(const char *name, struct state *sp, int doextend) 351{ 352 const char * p; 353 int i; 354 int fid; 355 int stored; 356 int nread; 357 typedef union { 358 struct tzhead tzhead; 359 char buf[2 * sizeof(struct tzhead) + 360 2 * sizeof *sp + 361 4 * TZ_MAX_TIMES]; 362 } u_t; 363 u_t * up; 364 365 up = calloc(1, sizeof *up); 366 if (up == NULL) 367 return -1; 368 369 sp->goback = sp->goahead = FALSE; 370 371 if ((fid = open_tzfile(name)) == -1) { 372 /* Could be a POSIX section 8-style TZ string. */ 373 goto oops; 374 } 375 376 nread = read(fid, up->buf, sizeof up->buf); 377 if (close(fid) == -1 || nread <= 0) 378 goto oops; 379 for (stored = 4; stored <= 8; stored *= 2) { 380 int ttisstdcnt; 381 int ttisgmtcnt; 382 383 ttisstdcnt = (int) detzcode(up->tzhead.tzh_ttisstdcnt); 384 ttisgmtcnt = (int) detzcode(up->tzhead.tzh_ttisgmtcnt); 385 sp->leapcnt = (int) detzcode(up->tzhead.tzh_leapcnt); 386 sp->timecnt = (int) detzcode(up->tzhead.tzh_timecnt); 387 sp->typecnt = (int) detzcode(up->tzhead.tzh_typecnt); 388 sp->charcnt = (int) detzcode(up->tzhead.tzh_charcnt); 389 p = up->tzhead.tzh_charcnt + sizeof up->tzhead.tzh_charcnt; 390 if (sp->leapcnt < 0 || sp->leapcnt > TZ_MAX_LEAPS || 391 sp->typecnt <= 0 || sp->typecnt > TZ_MAX_TYPES || 392 sp->timecnt < 0 || sp->timecnt > TZ_MAX_TIMES || 393 sp->charcnt < 0 || sp->charcnt > TZ_MAX_CHARS || 394 (ttisstdcnt != sp->typecnt && ttisstdcnt != 0) || 395 (ttisgmtcnt != sp->typecnt && ttisgmtcnt != 0)) 396 goto oops; 397 if (nread - (p - up->buf) < 398 sp->timecnt * stored + /* ats */ 399 sp->timecnt + /* types */ 400 sp->typecnt * 6 + /* ttinfos */ 401 sp->charcnt + /* chars */ 402 sp->leapcnt * (stored + 4) + /* lsinfos */ 403 ttisstdcnt + /* ttisstds */ 404 ttisgmtcnt) /* ttisgmts */ 405 goto oops; 406 for (i = 0; i < sp->timecnt; ++i) { 407 sp->ats[i] = (stored == 4) ? 408 detzcode(p) : detzcode64(p); 409 p += stored; 410 } 411 for (i = 0; i < sp->timecnt; ++i) { 412 sp->types[i] = (unsigned char) *p++; 413 if (sp->types[i] >= sp->typecnt) 414 goto oops; 415 } 416 for (i = 0; i < sp->typecnt; ++i) { 417 struct ttinfo * ttisp; 418 419 ttisp = &sp->ttis[i]; 420 ttisp->tt_gmtoff = detzcode(p); 421 p += 4; 422 ttisp->tt_isdst = (unsigned char) *p++; 423 if (ttisp->tt_isdst != 0 && ttisp->tt_isdst != 1) 424 goto oops; 425 ttisp->tt_abbrind = (unsigned char) *p++; 426 if (ttisp->tt_abbrind < 0 || 427 ttisp->tt_abbrind > sp->charcnt) 428 goto oops; 429 } 430 for (i = 0; i < sp->charcnt; ++i) 431 sp->chars[i] = *p++; 432 sp->chars[i] = '\0'; /* ensure '\0' at end */ 433 for (i = 0; i < sp->leapcnt; ++i) { 434 struct lsinfo * lsisp; 435 436 lsisp = &sp->lsis[i]; 437 lsisp->ls_trans = (stored == 4) ? 438 detzcode(p) : detzcode64(p); 439 p += stored; 440 lsisp->ls_corr = detzcode(p); 441 p += 4; 442 } 443 for (i = 0; i < sp->typecnt; ++i) { 444 struct ttinfo * ttisp; 445 446 ttisp = &sp->ttis[i]; 447 if (ttisstdcnt == 0) 448 ttisp->tt_ttisstd = FALSE; 449 else { 450 ttisp->tt_ttisstd = *p++; 451 if (ttisp->tt_ttisstd != TRUE && 452 ttisp->tt_ttisstd != FALSE) 453 goto oops; 454 } 455 } 456 for (i = 0; i < sp->typecnt; ++i) { 457 struct ttinfo * ttisp; 458 459 ttisp = &sp->ttis[i]; 460 if (ttisgmtcnt == 0) 461 ttisp->tt_ttisgmt = FALSE; 462 else { 463 ttisp->tt_ttisgmt = *p++; 464 if (ttisp->tt_ttisgmt != TRUE && 465 ttisp->tt_ttisgmt != FALSE) 466 goto oops; 467 } 468 } 469 /* 470 ** Out-of-sort ats should mean we're running on a 471 ** signed time_t system but using a data file with 472 ** unsigned values (or vice versa). 473 */ 474 for (i = 0; i < sp->timecnt - 2; ++i) 475 if (sp->ats[i] > sp->ats[i + 1]) { 476 ++i; 477 /* 478 ** Ignore the end (easy). 479 */ 480 sp->timecnt = i; 481 break; 482 } 483 /* 484 ** If this is an old file, we're done. 485 */ 486 if (up->tzhead.tzh_version[0] == '\0') 487 break; 488 nread -= p - up->buf; 489 for (i = 0; i < nread; ++i) 490 up->buf[i] = p[i]; 491 /* 492 ** If this is a narrow integer time_t system, we're done. 493 */ 494 if (stored >= sizeof(time_t)) 495 break; 496 } 497 if (doextend && nread > 2 && 498 up->buf[0] == '\n' && up->buf[nread - 1] == '\n' && 499 sp->typecnt + 2 <= TZ_MAX_TYPES) { 500 struct state ts; 501 int result; 502 503 up->buf[nread - 1] = '\0'; 504 result = tzparse(&up->buf[1], &ts, FALSE); 505 if (result == 0 && ts.typecnt == 2 && 506 sp->charcnt + ts.charcnt <= TZ_MAX_CHARS) { 507 for (i = 0; i < 2; ++i) 508 ts.ttis[i].tt_abbrind += 509 sp->charcnt; 510 for (i = 0; i < ts.charcnt; ++i) 511 sp->chars[sp->charcnt++] = 512 ts.chars[i]; 513 i = 0; 514 while (i < ts.timecnt && 515 ts.ats[i] <= 516 sp->ats[sp->timecnt - 1]) 517 ++i; 518 while (i < ts.timecnt && 519 sp->timecnt < TZ_MAX_TIMES) { 520 sp->ats[sp->timecnt] = 521 ts.ats[i]; 522 sp->types[sp->timecnt] = 523 sp->typecnt + 524 ts.types[i]; 525 ++sp->timecnt; 526 ++i; 527 } 528 sp->ttis[sp->typecnt++] = ts.ttis[0]; 529 sp->ttis[sp->typecnt++] = ts.ttis[1]; 530 } 531 } 532 if (sp->timecnt > 1) { 533 for (i = 1; i < sp->timecnt; ++i) { 534 if (typesequiv(sp, sp->types[i], sp->types[0]) && 535 differ_by_repeat(sp->ats[i], sp->ats[0])) { 536 sp->goback = TRUE; 537 break; 538 } 539 } 540 for (i = sp->timecnt - 2; i >= 0; --i) { 541 if (typesequiv(sp, sp->types[sp->timecnt - 1], 542 sp->types[i]) && 543 differ_by_repeat(sp->ats[sp->timecnt - 1], 544 sp->ats[i])) { 545 sp->goahead = TRUE; 546 break; 547 } 548 } 549 } 550 free(up); 551 return 0; 552oops: 553 free(up); 554 return -1; 555} 556 557static int 558typesequiv(const struct state *sp, int a, int b) 559{ 560 int result; 561 562 if (sp == NULL || 563 a < 0 || a >= sp->typecnt || 564 b < 0 || b >= sp->typecnt) 565 result = FALSE; 566 else { 567 const struct ttinfo * ap = &sp->ttis[a]; 568 const struct ttinfo * bp = &sp->ttis[b]; 569 result = ap->tt_gmtoff == bp->tt_gmtoff && 570 ap->tt_isdst == bp->tt_isdst && 571 ap->tt_ttisstd == bp->tt_ttisstd && 572 ap->tt_ttisgmt == bp->tt_ttisgmt && 573 strcmp(&sp->chars[ap->tt_abbrind], 574 &sp->chars[bp->tt_abbrind]) == 0; 575 } 576 return result; 577} 578 579static const int mon_lengths[2][MONSPERYEAR] = { 580 { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }, 581 { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 } 582}; 583 584static const int year_lengths[2] = { 585 DAYSPERNYEAR, DAYSPERLYEAR 586}; 587 588/* 589** Given a pointer into a time zone string, scan until a character that is not 590** a valid character in a zone name is found. Return a pointer to that 591** character. 592*/ 593 594static const char * 595getzname(const char *strp) 596{ 597 char c; 598 599 while ((c = *strp) != '\0' && !isdigit((unsigned char)c) && c != ',' && c != '-' && 600 c != '+') 601 ++strp; 602 return strp; 603} 604 605/* 606** Given a pointer into an extended time zone string, scan until the ending 607** delimiter of the zone name is located. Return a pointer to the delimiter. 608** 609** As with getzname above, the legal character set is actually quite 610** restricted, with other characters producing undefined results. 611** We don't do any checking here; checking is done later in common-case code. 612*/ 613 614static const char * 615getqzname(const char *strp, const int delim) 616{ 617 int c; 618 619 while ((c = *strp) != '\0' && c != delim) 620 ++strp; 621 return strp; 622} 623 624/* 625** Given a pointer into a time zone string, extract a number from that string. 626** Check that the number is within a specified range; if it is not, return 627** NULL. 628** Otherwise, return a pointer to the first character not part of the number. 629*/ 630 631static const char * 632getnum(const char *strp, int *nump, int min, int max) 633{ 634 char c; 635 int num; 636 637 if (strp == NULL || !isdigit((unsigned char)(c = *strp))) 638 return NULL; 639 num = 0; 640 do { 641 num = num * 10 + (c - '0'); 642 if (num > max) 643 return NULL; /* illegal value */ 644 c = *++strp; 645 } while (isdigit((unsigned char)c)); 646 if (num < min) 647 return NULL; /* illegal value */ 648 *nump = num; 649 return strp; 650} 651 652/* 653** Given a pointer into a time zone string, extract a number of seconds, 654** in hh[:mm[:ss]] form, from the string. 655** If any error occurs, return NULL. 656** Otherwise, return a pointer to the first character not part of the number 657** of seconds. 658*/ 659 660static const char * 661getsecs(const char *strp, long *secsp) 662{ 663 int num; 664 665 /* 666 ** `HOURSPERDAY * DAYSPERWEEK - 1' allows quasi-Posix rules like 667 ** "M10.4.6/26", which does not conform to Posix, 668 ** but which specifies the equivalent of 669 ** ``02:00 on the first Sunday on or after 23 Oct''. 670 */ 671 strp = getnum(strp, &num, 0, HOURSPERDAY * DAYSPERWEEK - 1); 672 if (strp == NULL) 673 return NULL; 674 *secsp = num * (long) SECSPERHOUR; 675 if (*strp == ':') { 676 ++strp; 677 strp = getnum(strp, &num, 0, MINSPERHOUR - 1); 678 if (strp == NULL) 679 return NULL; 680 *secsp += num * SECSPERMIN; 681 if (*strp == ':') { 682 ++strp; 683 /* `SECSPERMIN' allows for leap seconds. */ 684 strp = getnum(strp, &num, 0, SECSPERMIN); 685 if (strp == NULL) 686 return NULL; 687 *secsp += num; 688 } 689 } 690 return strp; 691} 692 693/* 694** Given a pointer into a time zone string, extract an offset, in 695** [+-]hh[:mm[:ss]] form, from the string. 696** If any error occurs, return NULL. 697** Otherwise, return a pointer to the first character not part of the time. 698*/ 699 700static const char * 701getoffset(const char *strp, long *offsetp) 702{ 703 int neg = 0; 704 705 if (*strp == '-') { 706 neg = 1; 707 ++strp; 708 } else if (*strp == '+') 709 ++strp; 710 strp = getsecs(strp, offsetp); 711 if (strp == NULL) 712 return NULL; /* illegal time */ 713 if (neg) 714 *offsetp = -*offsetp; 715 return strp; 716} 717 718/* 719** Given a pointer into a time zone string, extract a rule in the form 720** date[/time]. See POSIX section 8 for the format of "date" and "time". 721** If a valid rule is not found, return NULL. 722** Otherwise, return a pointer to the first character not part of the rule. 723*/ 724 725static const char * 726getrule(const char *strp, struct rule *rulep) 727{ 728 if (*strp == 'J') { 729 /* 730 ** Julian day. 731 */ 732 rulep->r_type = JULIAN_DAY; 733 ++strp; 734 strp = getnum(strp, &rulep->r_day, 1, DAYSPERNYEAR); 735 } else if (*strp == 'M') { 736 /* 737 ** Month, week, day. 738 */ 739 rulep->r_type = MONTH_NTH_DAY_OF_WEEK; 740 ++strp; 741 strp = getnum(strp, &rulep->r_mon, 1, MONSPERYEAR); 742 if (strp == NULL) 743 return NULL; 744 if (*strp++ != '.') 745 return NULL; 746 strp = getnum(strp, &rulep->r_week, 1, 5); 747 if (strp == NULL) 748 return NULL; 749 if (*strp++ != '.') 750 return NULL; 751 strp = getnum(strp, &rulep->r_day, 0, DAYSPERWEEK - 1); 752 } else if (isdigit((unsigned char)*strp)) { 753 /* 754 ** Day of year. 755 */ 756 rulep->r_type = DAY_OF_YEAR; 757 strp = getnum(strp, &rulep->r_day, 0, DAYSPERLYEAR - 1); 758 } else 759 return NULL; /* invalid format */ 760 if (strp == NULL) 761 return NULL; 762 if (*strp == '/') { 763 /* 764 ** Time specified. 765 */ 766 ++strp; 767 strp = getsecs(strp, &rulep->r_time); 768 } else 769 rulep->r_time = 2 * SECSPERHOUR; /* default = 2:00:00 */ 770 return strp; 771} 772 773/* 774** Given the Epoch-relative time of January 1, 00:00:00 UTC, in a year, the 775** year, a rule, and the offset from UTC at the time that rule takes effect, 776** calculate the Epoch-relative time that rule takes effect. 777*/ 778 779static time_t 780transtime(time_t janfirst, int year, const struct rule *rulep, long offset) 781{ 782 int leapyear; 783 time_t value; 784 int i; 785 int d, m1, yy0, yy1, yy2, dow; 786 787 value = 0; 788 leapyear = isleap(year); 789 switch (rulep->r_type) { 790 791 case JULIAN_DAY: 792 /* 793 ** Jn - Julian day, 1 == January 1, 60 == March 1 even in leap 794 ** years. 795 ** In non-leap years, or if the day number is 59 or less, just 796 ** add SECSPERDAY times the day number-1 to the time of 797 ** January 1, midnight, to get the day. 798 */ 799 value = janfirst + (rulep->r_day - 1) * SECSPERDAY; 800 if (leapyear && rulep->r_day >= 60) 801 value += SECSPERDAY; 802 break; 803 804 case DAY_OF_YEAR: 805 /* 806 ** n - day of year. 807 ** Just add SECSPERDAY times the day number to the time of 808 ** January 1, midnight, to get the day. 809 */ 810 value = janfirst + rulep->r_day * SECSPERDAY; 811 break; 812 813 case MONTH_NTH_DAY_OF_WEEK: 814 /* 815 ** Mm.n.d - nth "dth day" of month m. 816 */ 817 value = janfirst; 818 for (i = 0; i < rulep->r_mon - 1; ++i) 819 value += mon_lengths[leapyear][i] * SECSPERDAY; 820 821 /* 822 ** Use Zeller's Congruence to get day-of-week of first day of 823 ** month. 824 */ 825 m1 = (rulep->r_mon + 9) % 12 + 1; 826 yy0 = (rulep->r_mon <= 2) ? (year - 1) : year; 827 yy1 = yy0 / 100; 828 yy2 = yy0 % 100; 829 dow = ((26 * m1 - 2) / 10 + 830 1 + yy2 + yy2 / 4 + yy1 / 4 - 2 * yy1) % 7; 831 if (dow < 0) 832 dow += DAYSPERWEEK; 833 834 /* 835 ** "dow" is the day-of-week of the first day of the month. Get 836 ** the day-of-month (zero-origin) of the first "dow" day of the 837 ** month. 838 */ 839 d = rulep->r_day - dow; 840 if (d < 0) 841 d += DAYSPERWEEK; 842 for (i = 1; i < rulep->r_week; ++i) { 843 if (d + DAYSPERWEEK >= 844 mon_lengths[leapyear][rulep->r_mon - 1]) 845 break; 846 d += DAYSPERWEEK; 847 } 848 849 /* 850 ** "d" is the day-of-month (zero-origin) of the day we want. 851 */ 852 value += d * SECSPERDAY; 853 break; 854 } 855 856 /* 857 ** "value" is the Epoch-relative time of 00:00:00 UTC on the day in 858 ** question. To get the Epoch-relative time of the specified local 859 ** time on that day, add the transition time and the current offset 860 ** from UTC. 861 */ 862 return value + rulep->r_time + offset; 863} 864 865/* 866** Given a POSIX section 8-style TZ string, fill in the rule tables as 867** appropriate. 868*/ 869 870static int 871tzparse(const char *name, struct state *sp, int lastditch) 872{ 873 const char * stdname; 874 const char * dstname; 875 size_t stdlen; 876 size_t dstlen; 877 long stdoffset; 878 long dstoffset; 879 time_t * atp; 880 unsigned char * typep; 881 char * cp; 882 int load_result; 883 static struct ttinfo zttinfo; 884 885 dstname = NULL; 886 stdname = name; 887 if (lastditch) { 888 stdlen = strlen(name); /* length of standard zone name */ 889 name += stdlen; 890 if (stdlen >= sizeof sp->chars) 891 stdlen = (sizeof sp->chars) - 1; 892 stdoffset = 0; 893 } else { 894 if (*name == '<') { 895 name++; 896 stdname = name; 897 name = getqzname(name, '>'); 898 if (*name != '>') 899 return (-1); 900 stdlen = name - stdname; 901 name++; 902 } else { 903 name = getzname(name); 904 stdlen = name - stdname; 905 } 906 if (*name == '\0') 907 return -1; 908 name = getoffset(name, &stdoffset); 909 if (name == NULL) 910 return -1; 911 } 912 load_result = tzload(TZDEFRULES, sp, FALSE); 913 if (load_result != 0) 914 sp->leapcnt = 0; /* so, we're off a little */ 915 if (*name != '\0') { 916 if (*name == '<') { 917 dstname = ++name; 918 name = getqzname(name, '>'); 919 if (*name != '>') 920 return -1; 921 dstlen = name - dstname; 922 name++; 923 } else { 924 dstname = name; 925 name = getzname(name); 926 dstlen = name - dstname; /* length of DST zone name */ 927 } 928 if (*name != '\0' && *name != ',' && *name != ';') { 929 name = getoffset(name, &dstoffset); 930 if (name == NULL) 931 return -1; 932 } else 933 dstoffset = stdoffset - SECSPERHOUR; 934 if (*name == '\0' && load_result != 0) 935 name = TZDEFRULESTRING; 936 if (*name == ',' || *name == ';') { 937 struct rule start; 938 struct rule end; 939 int year; 940 time_t janfirst; 941 time_t starttime; 942 time_t endtime; 943 944 ++name; 945 if ((name = getrule(name, &start)) == NULL) 946 return -1; 947 if (*name++ != ',') 948 return -1; 949 if ((name = getrule(name, &end)) == NULL) 950 return -1; 951 if (*name != '\0') 952 return -1; 953 sp->typecnt = 2; /* standard time and DST */ 954 /* 955 ** Two transitions per year, from EPOCH_YEAR forward. 956 */ 957 sp->ttis[0] = sp->ttis[1] = zttinfo; 958 sp->ttis[0].tt_gmtoff = -dstoffset; 959 sp->ttis[0].tt_isdst = 1; 960 sp->ttis[0].tt_abbrind = stdlen + 1; 961 sp->ttis[1].tt_gmtoff = -stdoffset; 962 sp->ttis[1].tt_isdst = 0; 963 sp->ttis[1].tt_abbrind = 0; 964 atp = sp->ats; 965 typep = sp->types; 966 janfirst = 0; 967 sp->timecnt = 0; 968 for (year = EPOCH_YEAR; 969 sp->timecnt + 2 <= TZ_MAX_TIMES; 970 ++year) { 971 time_t newfirst; 972 973 starttime = transtime(janfirst, year, &start, 974 stdoffset); 975 endtime = transtime(janfirst, year, &end, 976 dstoffset); 977 if (starttime > endtime) { 978 *atp++ = endtime; 979 *typep++ = 1; /* DST ends */ 980 *atp++ = starttime; 981 *typep++ = 0; /* DST begins */ 982 } else { 983 *atp++ = starttime; 984 *typep++ = 0; /* DST begins */ 985 *atp++ = endtime; 986 *typep++ = 1; /* DST ends */ 987 } 988 sp->timecnt += 2; 989 newfirst = janfirst; 990 newfirst += year_lengths[isleap(year)] * 991 SECSPERDAY; 992 if (newfirst <= janfirst) 993 break; 994 janfirst = newfirst; 995 } 996 } else { 997 long theirstdoffset; 998 long theirdstoffset; 999 long theiroffset; 1000 int isdst; 1001 int i; 1002 int j; 1003 1004 if (*name != '\0') 1005 return -1; 1006 /* 1007 ** Initial values of theirstdoffset and theirdstoffset. 1008 */ 1009 theirstdoffset = 0; 1010 for (i = 0; i < sp->timecnt; ++i) { 1011 j = sp->types[i]; 1012 if (!sp->ttis[j].tt_isdst) { 1013 theirstdoffset = 1014 -sp->ttis[j].tt_gmtoff; 1015 break; 1016 } 1017 } 1018 theirdstoffset = 0; 1019 for (i = 0; i < sp->timecnt; ++i) { 1020 j = sp->types[i]; 1021 if (sp->ttis[j].tt_isdst) { 1022 theirdstoffset = 1023 -sp->ttis[j].tt_gmtoff; 1024 break; 1025 } 1026 } 1027 /* 1028 ** Initially we're assumed to be in standard time. 1029 */ 1030 isdst = FALSE; 1031 theiroffset = theirstdoffset; 1032 /* 1033 ** Now juggle transition times and types 1034 ** tracking offsets as you do. 1035 */ 1036 for (i = 0; i < sp->timecnt; ++i) { 1037 j = sp->types[i]; 1038 sp->types[i] = sp->ttis[j].tt_isdst; 1039 if (sp->ttis[j].tt_ttisgmt) { 1040 /* No adjustment to transition time */ 1041 } else { 1042 /* 1043 ** If summer time is in effect, and the 1044 ** transition time was not specified as 1045 ** standard time, add the summer time 1046 ** offset to the transition time; 1047 ** otherwise, add the standard time 1048 ** offset to the transition time. 1049 */ 1050 /* 1051 ** Transitions from DST to DDST 1052 ** will effectively disappear since 1053 ** POSIX provides for only one DST 1054 ** offset. 1055 */ 1056 if (isdst && !sp->ttis[j].tt_ttisstd) { 1057 sp->ats[i] += dstoffset - 1058 theirdstoffset; 1059 } else { 1060 sp->ats[i] += stdoffset - 1061 theirstdoffset; 1062 } 1063 } 1064 theiroffset = -sp->ttis[j].tt_gmtoff; 1065 if (sp->ttis[j].tt_isdst) 1066 theirdstoffset = theiroffset; 1067 else 1068 theirstdoffset = theiroffset; 1069 } 1070 /* 1071 ** Finally, fill in ttis. 1072 */ 1073 sp->ttis[0] = sp->ttis[1] = zttinfo; 1074 sp->ttis[0].tt_gmtoff = -stdoffset; 1075 sp->ttis[0].tt_isdst = FALSE; 1076 sp->ttis[0].tt_abbrind = 0; 1077 sp->ttis[1].tt_gmtoff = -dstoffset; 1078 sp->ttis[1].tt_isdst = TRUE; 1079 sp->ttis[1].tt_abbrind = stdlen + 1; 1080 sp->typecnt = 2; 1081 } 1082 } else { 1083 dstlen = 0; 1084 sp->typecnt = 1; /* only standard time */ 1085 sp->timecnt = 0; 1086 sp->ttis[0] = zttinfo; 1087 sp->ttis[0].tt_gmtoff = -stdoffset; 1088 sp->ttis[0].tt_isdst = 0; 1089 sp->ttis[0].tt_abbrind = 0; 1090 } 1091 sp->charcnt = stdlen + 1; 1092 if (dstlen != 0) 1093 sp->charcnt += dstlen + 1; 1094 if ((size_t) sp->charcnt > sizeof sp->chars) 1095 return -1; 1096 cp = sp->chars; 1097 strlcpy(cp, stdname, stdlen + 1); 1098 cp += stdlen + 1; 1099 if (dstlen != 0) { 1100 strlcpy(cp, dstname, dstlen + 1); 1101 } 1102 return 0; 1103} 1104 1105static void 1106gmtload(struct state *sp) 1107{ 1108 if (tzload(gmt, sp, TRUE) != 0) 1109 (void) tzparse(gmt, sp, TRUE); 1110} 1111 1112static void 1113tzsetwall_basic(void) 1114{ 1115 if (lcl_is_set < 0) 1116 return; 1117 lcl_is_set = -1; 1118 1119 if (lclptr == NULL) { 1120 lclptr = calloc(1, sizeof *lclptr); 1121 if (lclptr == NULL) { 1122 settzname(); /* all we can do */ 1123 return; 1124 } 1125 } 1126 if (tzload(NULL, lclptr, TRUE) != 0) 1127 gmtload(lclptr); 1128 settzname(); 1129} 1130 1131#ifndef STD_INSPIRED 1132/* 1133** A non-static declaration of tzsetwall in a system header file 1134** may cause a warning about this upcoming static declaration... 1135*/ 1136static 1137#endif /* !defined STD_INSPIRED */ 1138void 1139tzsetwall(void) 1140{ 1141 _THREAD_PRIVATE_MUTEX_LOCK(lcl); 1142 tzsetwall_basic(); 1143 _THREAD_PRIVATE_MUTEX_UNLOCK(lcl); 1144} 1145 1146static void 1147tzset_basic(void) 1148{ 1149 static char lcl_TZname[TZ_STRLEN_MAX + 1]; 1150 const char * name; 1151 1152 name = getenv("TZ"); 1153 if (name == NULL) { 1154 tzsetwall_basic(); 1155 return; 1156 } 1157 1158 if (lcl_is_set > 0 && strcmp(lcl_TZname, name) == 0) 1159 return; 1160 lcl_is_set = strlen(name) < sizeof lcl_TZname; 1161 if (lcl_is_set) 1162 strlcpy(lcl_TZname, name, sizeof lcl_TZname); 1163 1164 /* Ignore TZ for setuid/setgid processes. */ 1165 if (issetugid()) 1166 name = TZDEFAULT; 1167 1168 if (lclptr == NULL) { 1169 lclptr = calloc(1, sizeof *lclptr); 1170 if (lclptr == NULL) { 1171 settzname(); /* all we can do */ 1172 return; 1173 } 1174 } 1175 if (*name == '\0') { 1176 /* 1177 ** User wants it fast rather than right. 1178 */ 1179 lclptr->leapcnt = 0; /* so, we're off a little */ 1180 lclptr->timecnt = 0; 1181 lclptr->typecnt = 0; 1182 lclptr->ttis[0].tt_isdst = 0; 1183 lclptr->ttis[0].tt_gmtoff = 0; 1184 lclptr->ttis[0].tt_abbrind = 0; 1185 strlcpy(lclptr->chars, gmt, sizeof lclptr->chars); 1186 } else if (tzload(name, lclptr, TRUE) != 0) { 1187 if (name[0] == ':' || tzparse(name, lclptr, FALSE) != 0) 1188 gmtload(lclptr); 1189 } 1190 settzname(); 1191} 1192 1193void 1194tzset(void) 1195{ 1196 _THREAD_PRIVATE_MUTEX_LOCK(lcl); 1197 tzset_basic(); 1198 _THREAD_PRIVATE_MUTEX_UNLOCK(lcl); 1199} 1200DEF_WEAK(tzset); 1201 1202/* 1203** The easy way to behave "as if no library function calls" localtime 1204** is to not call it--so we drop its guts into "localsub", which can be 1205** freely called. (And no, the PANS doesn't require the above behavior-- 1206** but it *is* desirable.) 1207** 1208** The unused offset argument is for the benefit of mktime variants. 1209*/ 1210 1211static struct tm * 1212localsub(const time_t *timep, long offset, struct tm *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 if (sp == NULL) 1222 return gmtsub(timep, offset, tmp); 1223 if ((sp->goback && t < sp->ats[0]) || 1224 (sp->goahead && t > sp->ats[sp->timecnt - 1])) { 1225 time_t newt = t; 1226 time_t seconds; 1227 time_t tcycles; 1228 int_fast64_t icycles; 1229 1230 if (t < sp->ats[0]) 1231 seconds = sp->ats[0] - t; 1232 else 1233 seconds = t - sp->ats[sp->timecnt - 1]; 1234 --seconds; 1235 tcycles = seconds / YEARSPERREPEAT / AVGSECSPERYEAR; 1236 ++tcycles; 1237 icycles = tcycles; 1238 if (tcycles - icycles >= 1 || icycles - tcycles >= 1) 1239 return NULL; 1240 seconds = icycles; 1241 seconds *= YEARSPERREPEAT; 1242 seconds *= AVGSECSPERYEAR; 1243 if (t < sp->ats[0]) 1244 newt += seconds; 1245 else 1246 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 1258 newy += icycles * YEARSPERREPEAT; 1259 tmp->tm_year = newy; 1260 if (tmp->tm_year != newy) 1261 return NULL; 1262 } 1263 return result; 1264 } 1265 if (sp->timecnt == 0 || t < sp->ats[0]) { 1266 i = 0; 1267 while (sp->ttis[i].tt_isdst) { 1268 if (++i >= sp->typecnt) { 1269 i = 0; 1270 break; 1271 } 1272 } 1273 } else { 1274 int lo = 1; 1275 int hi = sp->timecnt; 1276 1277 while (lo < hi) { 1278 int mid = (lo + hi) >> 1; 1279 1280 if (t < sp->ats[mid]) 1281 hi = mid; 1282 else 1283 lo = mid + 1; 1284 } 1285 i = (int) sp->types[lo - 1]; 1286 } 1287 ttisp = &sp->ttis[i]; 1288 /* 1289 ** To get (wrong) behavior that's compatible with System V Release 2.0 1290 ** you'd replace the statement below with 1291 ** t += ttisp->tt_gmtoff; 1292 ** timesub(&t, 0L, sp, tmp); 1293 */ 1294 result = timesub(&t, ttisp->tt_gmtoff, sp, tmp); 1295 tmp->tm_isdst = ttisp->tt_isdst; 1296 tzname[tmp->tm_isdst] = &sp->chars[ttisp->tt_abbrind]; 1297 tmp->tm_zone = &sp->chars[ttisp->tt_abbrind]; 1298 return result; 1299} 1300 1301/* 1302** Re-entrant version of localtime. 1303*/ 1304 1305struct tm * 1306localtime_r(const time_t *timep, struct tm *p_tm) 1307{ 1308 _THREAD_PRIVATE_MUTEX_LOCK(lcl); 1309 tzset_basic(); 1310 p_tm = localsub(timep, 0L, p_tm); 1311 _THREAD_PRIVATE_MUTEX_UNLOCK(lcl); 1312 return p_tm; 1313} 1314DEF_WEAK(localtime_r); 1315 1316struct tm * 1317localtime(const time_t *timep) 1318{ 1319 _THREAD_PRIVATE_KEY(localtime); 1320 struct tm * p_tm = (struct tm*)_THREAD_PRIVATE(localtime, tm, NULL); 1321 1322 if (p_tm == NULL) 1323 return NULL; 1324 return localtime_r(timep, p_tm); 1325} 1326DEF_STRONG(localtime); 1327 1328/* 1329** gmtsub is to gmtime as localsub is to localtime. 1330*/ 1331 1332static struct tm * 1333gmtsub(const time_t *timep, long offset, struct tm *tmp) 1334{ 1335 struct tm * result; 1336 1337 _THREAD_PRIVATE_MUTEX_LOCK(gmt); 1338 if (!gmt_is_set) { 1339 gmt_is_set = TRUE; 1340 gmtptr = calloc(1, sizeof(*gmtptr)); 1341 if (gmtptr != NULL) 1342 gmtload(gmtptr); 1343 } 1344 _THREAD_PRIVATE_MUTEX_UNLOCK(gmt); 1345 result = timesub(timep, offset, gmtptr, tmp); 1346 /* 1347 ** Could get fancy here and deliver something such as 1348 ** "UTC+xxxx" or "UTC-xxxx" if offset is non-zero, 1349 ** but this is no time for a treasure hunt. 1350 */ 1351 if (offset != 0) 1352 tmp->tm_zone = wildabbr; 1353 else { 1354 if (gmtptr == NULL) 1355 tmp->tm_zone = (char *)gmt; 1356 else 1357 tmp->tm_zone = gmtptr->chars; 1358 } 1359 return result; 1360} 1361 1362/* 1363** Re-entrant version of gmtime. 1364*/ 1365 1366struct tm * 1367gmtime_r(const time_t *timep, struct tm *p_tm) 1368{ 1369 return gmtsub(timep, 0L, p_tm); 1370} 1371DEF_WEAK(gmtime_r); 1372 1373struct tm * 1374gmtime(const time_t *timep) 1375{ 1376 _THREAD_PRIVATE_KEY(gmtime); 1377 struct tm * p_tm = (struct tm*) _THREAD_PRIVATE(gmtime, tm, NULL); 1378 1379 if (p_tm == NULL) 1380 return NULL; 1381 return gmtime_r(timep, p_tm); 1382 1383} 1384DEF_WEAK(gmtime); 1385 1386#ifdef STD_INSPIRED 1387 1388struct tm * 1389offtime(const time_t *timep, long offset) 1390{ 1391 return gmtsub(timep, offset, &tm); 1392} 1393 1394#endif /* defined STD_INSPIRED */ 1395 1396/* 1397** Return the number of leap years through the end of the given year 1398** where, to make the math easy, the answer for year zero is defined as zero. 1399*/ 1400 1401static int 1402leaps_thru_end_of(int y) 1403{ 1404 return (y >= 0) ? (y / 4 - y / 100 + y / 400) : 1405 -(leaps_thru_end_of(-(y + 1)) + 1); 1406} 1407 1408static struct tm * 1409timesub(const time_t *timep, long offset, const struct state *sp, struct tm *tmp) 1410{ 1411 const struct lsinfo * lp; 1412 time_t tdays; 1413 int idays; /* unsigned would be so 2003 */ 1414 long rem; 1415 int y; 1416 const int * ip; 1417 long corr; 1418 int hit; 1419 int i; 1420 long seconds; 1421 1422 corr = 0; 1423 hit = 0; 1424 i = (sp == NULL) ? 0 : sp->leapcnt; 1425 while (--i >= 0) { 1426 lp = &sp->lsis[i]; 1427 if (*timep >= lp->ls_trans) { 1428 if (*timep == lp->ls_trans) { 1429 hit = ((i == 0 && lp->ls_corr > 0) || 1430 lp->ls_corr > sp->lsis[i - 1].ls_corr); 1431 if (hit) { 1432 while (i > 0 && 1433 sp->lsis[i].ls_trans == 1434 sp->lsis[i - 1].ls_trans + 1 && 1435 sp->lsis[i].ls_corr == 1436 sp->lsis[i - 1].ls_corr + 1) { 1437 ++hit; 1438 --i; 1439 } 1440 } 1441 } 1442 corr = lp->ls_corr; 1443 break; 1444 } 1445 } 1446 y = EPOCH_YEAR; 1447 tdays = *timep / SECSPERDAY; 1448 rem = *timep - tdays * SECSPERDAY; 1449 while (tdays < 0 || tdays >= year_lengths[isleap(y)]) { 1450 int newy; 1451 time_t tdelta; 1452 int idelta; 1453 int leapdays; 1454 1455 tdelta = tdays / DAYSPERLYEAR; 1456 idelta = tdelta; 1457 if (tdelta - idelta >= 1 || idelta - tdelta >= 1) 1458 return NULL; 1459 if (idelta == 0) 1460 idelta = (tdays < 0) ? -1 : 1; 1461 newy = y; 1462 if (increment_overflow(&newy, idelta)) 1463 return NULL; 1464 leapdays = leaps_thru_end_of(newy - 1) - 1465 leaps_thru_end_of(y - 1); 1466 tdays -= ((time_t) newy - y) * DAYSPERNYEAR; 1467 tdays -= leapdays; 1468 y = newy; 1469 } 1470 1471 seconds = tdays * SECSPERDAY + 0.5; 1472 tdays = seconds / SECSPERDAY; 1473 rem += seconds - tdays * SECSPERDAY; 1474 1475 /* 1476 ** Given the range, we can now fearlessly cast... 1477 */ 1478 idays = tdays; 1479 rem += offset - corr; 1480 while (rem < 0) { 1481 rem += SECSPERDAY; 1482 --idays; 1483 } 1484 while (rem >= SECSPERDAY) { 1485 rem -= SECSPERDAY; 1486 ++idays; 1487 } 1488 while (idays < 0) { 1489 if (increment_overflow(&y, -1)) 1490 return NULL; 1491 idays += year_lengths[isleap(y)]; 1492 } 1493 while (idays >= year_lengths[isleap(y)]) { 1494 idays -= year_lengths[isleap(y)]; 1495 if (increment_overflow(&y, 1)) 1496 return NULL; 1497 } 1498 tmp->tm_year = y; 1499 if (increment_overflow(&tmp->tm_year, -TM_YEAR_BASE)) 1500 return NULL; 1501 tmp->tm_yday = idays; 1502 /* 1503 ** The "extra" mods below avoid overflow problems. 1504 */ 1505 tmp->tm_wday = EPOCH_WDAY + 1506 ((y - EPOCH_YEAR) % DAYSPERWEEK) * 1507 (DAYSPERNYEAR % DAYSPERWEEK) + 1508 leaps_thru_end_of(y - 1) - 1509 leaps_thru_end_of(EPOCH_YEAR - 1) + 1510 idays; 1511 tmp->tm_wday %= DAYSPERWEEK; 1512 if (tmp->tm_wday < 0) 1513 tmp->tm_wday += DAYSPERWEEK; 1514 tmp->tm_hour = (int) (rem / SECSPERHOUR); 1515 rem %= SECSPERHOUR; 1516 tmp->tm_min = (int) (rem / SECSPERMIN); 1517 /* 1518 ** A positive leap second requires a special 1519 ** representation. This uses "... ??:59:60" et seq. 1520 */ 1521 tmp->tm_sec = (int) (rem % SECSPERMIN) + hit; 1522 ip = mon_lengths[isleap(y)]; 1523 for (tmp->tm_mon = 0; idays >= ip[tmp->tm_mon]; ++(tmp->tm_mon)) 1524 idays -= ip[tmp->tm_mon]; 1525 tmp->tm_mday = (int) (idays + 1); 1526 tmp->tm_isdst = 0; 1527 tmp->tm_gmtoff = offset; 1528 return tmp; 1529} 1530 1531char * 1532ctime(const time_t *timep) 1533{ 1534/* 1535** Section 4.12.3.2 of X3.159-1989 requires that 1536** The ctime function converts the calendar time pointed to by timer 1537** to local time in the form of a string. It is equivalent to 1538** asctime(localtime(timer)) 1539*/ 1540 return asctime(localtime(timep)); 1541} 1542 1543char * 1544ctime_r(const time_t *timep, char *buf) 1545{ 1546 struct tm mytm; 1547 1548 return asctime_r(localtime_r(timep, &mytm), buf); 1549} 1550 1551/* 1552** Adapted from code provided by Robert Elz, who writes: 1553** The "best" way to do mktime I think is based on an idea of Bob 1554** Kridle's (so its said...) from a long time ago. 1555** It does a binary search of the time_t space. Since time_t's are 1556** just 32 bits, its a max of 32 iterations (even at 64 bits it 1557** would still be very reasonable). 1558*/ 1559 1560#ifndef WRONG 1561#define WRONG (-1) 1562#endif /* !defined WRONG */ 1563 1564/* 1565** Normalize logic courtesy Paul Eggert. 1566*/ 1567 1568static int 1569increment_overflow(int *ip, int j) 1570{ 1571 int const i = *ip; 1572 1573 /* 1574 ** If i >= 0 there can only be overflow if i + j > INT_MAX 1575 ** or if j > INT_MAX - i; given i >= 0, INT_MAX - i cannot overflow. 1576 ** If i < 0 there can only be overflow if i + j < INT_MIN 1577 ** or if j < INT_MIN - i; given i < 0, INT_MIN - i cannot overflow. 1578 */ 1579 if ((i >= 0) ? (j > INT_MAX - i) : (j < INT_MIN - i)) 1580 return TRUE; 1581 *ip += j; 1582 return FALSE; 1583} 1584 1585static int 1586long_increment_overflow(long *lp, int m) 1587{ 1588 long const l = *lp; 1589 1590 if ((l >= 0) ? (m > LONG_MAX - l) : (m < LONG_MIN - l)) 1591 return TRUE; 1592 *lp += m; 1593 return FALSE; 1594} 1595 1596static int 1597normalize_overflow(int *tensptr, int *unitsptr, int base) 1598{ 1599 int tensdelta; 1600 1601 tensdelta = (*unitsptr >= 0) ? 1602 (*unitsptr / base) : 1603 (-1 - (-1 - *unitsptr) / base); 1604 *unitsptr -= tensdelta * base; 1605 return increment_overflow(tensptr, tensdelta); 1606} 1607 1608static int 1609long_normalize_overflow(long *tensptr, int *unitsptr, int base) 1610{ 1611 int tensdelta; 1612 1613 tensdelta = (*unitsptr >= 0) ? 1614 (*unitsptr / base) : 1615 (-1 - (-1 - *unitsptr) / base); 1616 *unitsptr -= tensdelta * base; 1617 return long_increment_overflow(tensptr, tensdelta); 1618} 1619 1620static int 1621tmcomp(const struct tm *atmp, const struct tm *btmp) 1622{ 1623 int result; 1624 1625 if ((result = (atmp->tm_year - btmp->tm_year)) == 0 && 1626 (result = (atmp->tm_mon - btmp->tm_mon)) == 0 && 1627 (result = (atmp->tm_mday - btmp->tm_mday)) == 0 && 1628 (result = (atmp->tm_hour - btmp->tm_hour)) == 0 && 1629 (result = (atmp->tm_min - btmp->tm_min)) == 0) 1630 result = atmp->tm_sec - btmp->tm_sec; 1631 return result; 1632} 1633 1634static time_t 1635time2sub(struct tm *tmp, struct tm *(*funcp)(const time_t *, long, struct tm *), 1636 long offset, int *okayp, int do_norm_secs) 1637{ 1638 const struct state * sp; 1639 int dir; 1640 int i, j; 1641 int saved_seconds; 1642 long li; 1643 time_t lo; 1644 time_t hi; 1645 long y; 1646 time_t newt; 1647 time_t t; 1648 struct tm yourtm, mytm; 1649 1650 *okayp = FALSE; 1651 yourtm = *tmp; 1652 if (do_norm_secs) { 1653 if (normalize_overflow(&yourtm.tm_min, &yourtm.tm_sec, 1654 SECSPERMIN)) 1655 return WRONG; 1656 } 1657 if (normalize_overflow(&yourtm.tm_hour, &yourtm.tm_min, MINSPERHOUR)) 1658 return WRONG; 1659 if (normalize_overflow(&yourtm.tm_mday, &yourtm.tm_hour, HOURSPERDAY)) 1660 return WRONG; 1661 y = yourtm.tm_year; 1662 if (long_normalize_overflow(&y, &yourtm.tm_mon, MONSPERYEAR)) 1663 return WRONG; 1664 /* 1665 ** Turn y into an actual year number for now. 1666 ** It is converted back to an offset from TM_YEAR_BASE later. 1667 */ 1668 if (long_increment_overflow(&y, TM_YEAR_BASE)) 1669 return WRONG; 1670 while (yourtm.tm_mday <= 0) { 1671 if (long_increment_overflow(&y, -1)) 1672 return WRONG; 1673 li = y + (1 < yourtm.tm_mon); 1674 yourtm.tm_mday += year_lengths[isleap(li)]; 1675 } 1676 while (yourtm.tm_mday > DAYSPERLYEAR) { 1677 li = y + (1 < yourtm.tm_mon); 1678 yourtm.tm_mday -= year_lengths[isleap(li)]; 1679 if (long_increment_overflow(&y, 1)) 1680 return WRONG; 1681 } 1682 for ( ; ; ) { 1683 i = mon_lengths[isleap(y)][yourtm.tm_mon]; 1684 if (yourtm.tm_mday <= i) 1685 break; 1686 yourtm.tm_mday -= i; 1687 if (++yourtm.tm_mon >= MONSPERYEAR) { 1688 yourtm.tm_mon = 0; 1689 if (long_increment_overflow(&y, 1)) 1690 return WRONG; 1691 } 1692 } 1693 if (long_increment_overflow(&y, -TM_YEAR_BASE)) 1694 return WRONG; 1695 yourtm.tm_year = y; 1696 if (yourtm.tm_year != y) 1697 return WRONG; 1698 if (yourtm.tm_sec >= 0 && yourtm.tm_sec < SECSPERMIN) 1699 saved_seconds = 0; 1700 else if (y + TM_YEAR_BASE < EPOCH_YEAR) { 1701 /* 1702 ** We can't set tm_sec to 0, because that might push the 1703 ** time below the minimum representable time. 1704 ** Set tm_sec to 59 instead. 1705 ** This assumes that the minimum representable time is 1706 ** not in the same minute that a leap second was deleted from, 1707 ** which is a safer assumption than using 58 would be. 1708 */ 1709 if (increment_overflow(&yourtm.tm_sec, 1 - SECSPERMIN)) 1710 return WRONG; 1711 saved_seconds = yourtm.tm_sec; 1712 yourtm.tm_sec = SECSPERMIN - 1; 1713 } else { 1714 saved_seconds = yourtm.tm_sec; 1715 yourtm.tm_sec = 0; 1716 } 1717 /* 1718 ** Do a binary search (this works whatever time_t's type is). 1719 */ 1720 lo = 1; 1721 for (i = 0; i < (int) TYPE_BIT(time_t) - 1; ++i) 1722 lo *= 2; 1723 hi = -(lo + 1); 1724 for ( ; ; ) { 1725 t = lo / 2 + hi / 2; 1726 if (t < lo) 1727 t = lo; 1728 else if (t > hi) 1729 t = hi; 1730 if ((*funcp)(&t, offset, &mytm) == NULL) { 1731 /* 1732 ** Assume that t is too extreme to be represented in 1733 ** a struct tm; arrange things so that it is less 1734 ** extreme on the next pass. 1735 */ 1736 dir = (t > 0) ? 1 : -1; 1737 } else 1738 dir = tmcomp(&mytm, &yourtm); 1739 if (dir != 0) { 1740 if (t == lo) { 1741 ++t; 1742 if (t <= lo) 1743 return WRONG; 1744 ++lo; 1745 } else if (t == hi) { 1746 --t; 1747 if (t >= hi) 1748 return WRONG; 1749 --hi; 1750 } 1751 if (lo > hi) 1752 return WRONG; 1753 if (dir > 0) 1754 hi = t; 1755 else 1756 lo = t; 1757 continue; 1758 } 1759 if (yourtm.tm_isdst < 0 || mytm.tm_isdst == yourtm.tm_isdst) 1760 break; 1761 /* 1762 ** Right time, wrong type. 1763 ** Hunt for right time, right type. 1764 ** It's okay to guess wrong since the guess 1765 ** gets checked. 1766 */ 1767 sp = (const struct state *) 1768 ((funcp == localsub) ? lclptr : gmtptr); 1769 if (sp == NULL) 1770 return WRONG; 1771 for (i = sp->typecnt - 1; i >= 0; --i) { 1772 if (sp->ttis[i].tt_isdst != yourtm.tm_isdst) 1773 continue; 1774 for (j = sp->typecnt - 1; j >= 0; --j) { 1775 if (sp->ttis[j].tt_isdst == yourtm.tm_isdst) 1776 continue; 1777 newt = t + sp->ttis[j].tt_gmtoff - 1778 sp->ttis[i].tt_gmtoff; 1779 if ((*funcp)(&newt, offset, &mytm) == NULL) 1780 continue; 1781 if (tmcomp(&mytm, &yourtm) != 0) 1782 continue; 1783 if (mytm.tm_isdst != yourtm.tm_isdst) 1784 continue; 1785 /* 1786 ** We have a match. 1787 */ 1788 t = newt; 1789 goto label; 1790 } 1791 } 1792 return WRONG; 1793 } 1794label: 1795 newt = t + saved_seconds; 1796 if ((newt < t) != (saved_seconds < 0)) 1797 return WRONG; 1798 t = newt; 1799 if ((*funcp)(&t, offset, tmp)) 1800 *okayp = TRUE; 1801 return t; 1802} 1803 1804static time_t 1805time2(struct tm *tmp, struct tm * (*funcp)(const time_t *, long, struct tm *), 1806 long offset, int *okayp) 1807{ 1808 time_t t; 1809 1810 /* 1811 ** First try without normalization of seconds 1812 ** (in case tm_sec contains a value associated with a leap second). 1813 ** If that fails, try with normalization of seconds. 1814 */ 1815 t = time2sub(tmp, funcp, offset, okayp, FALSE); 1816 return *okayp ? t : time2sub(tmp, funcp, offset, okayp, TRUE); 1817} 1818 1819static time_t 1820time1(struct tm *tmp, struct tm * (*funcp)(const time_t *, long, struct tm *), 1821 long offset) 1822{ 1823 time_t t; 1824 const struct state * sp; 1825 int samei, otheri; 1826 int sameind, otherind; 1827 int i; 1828 int nseen; 1829 int seen[TZ_MAX_TYPES]; 1830 int types[TZ_MAX_TYPES]; 1831 int okay; 1832 1833 if (tmp == NULL) { 1834 errno = EINVAL; 1835 return WRONG; 1836 } 1837 if (tmp->tm_isdst > 1) 1838 tmp->tm_isdst = 1; 1839 t = time2(tmp, funcp, offset, &okay); 1840#ifdef PCTS 1841 /* 1842 ** PCTS code courtesy Grant Sullivan. 1843 */ 1844 if (okay) 1845 return t; 1846 if (tmp->tm_isdst < 0) 1847 tmp->tm_isdst = 0; /* reset to std and try again */ 1848#endif /* defined PCTS */ 1849#ifndef PCTS 1850 if (okay || tmp->tm_isdst < 0) 1851 return t; 1852#endif /* !defined PCTS */ 1853 /* 1854 ** We're supposed to assume that somebody took a time of one type 1855 ** and did some math on it that yielded a "struct tm" that's bad. 1856 ** We try to divine the type they started from and adjust to the 1857 ** type they need. 1858 */ 1859 sp = (const struct state *) ((funcp == localsub) ? lclptr : gmtptr); 1860 if (sp == NULL) 1861 return WRONG; 1862 for (i = 0; i < sp->typecnt; ++i) 1863 seen[i] = FALSE; 1864 nseen = 0; 1865 for (i = sp->timecnt - 1; i >= 0; --i) { 1866 if (!seen[sp->types[i]]) { 1867 seen[sp->types[i]] = TRUE; 1868 types[nseen++] = sp->types[i]; 1869 } 1870 } 1871 for (sameind = 0; sameind < nseen; ++sameind) { 1872 samei = types[sameind]; 1873 if (sp->ttis[samei].tt_isdst != tmp->tm_isdst) 1874 continue; 1875 for (otherind = 0; otherind < nseen; ++otherind) { 1876 otheri = types[otherind]; 1877 if (sp->ttis[otheri].tt_isdst == tmp->tm_isdst) 1878 continue; 1879 tmp->tm_sec += sp->ttis[otheri].tt_gmtoff - 1880 sp->ttis[samei].tt_gmtoff; 1881 tmp->tm_isdst = !tmp->tm_isdst; 1882 t = time2(tmp, funcp, offset, &okay); 1883 if (okay) 1884 return t; 1885 tmp->tm_sec -= sp->ttis[otheri].tt_gmtoff - 1886 sp->ttis[samei].tt_gmtoff; 1887 tmp->tm_isdst = !tmp->tm_isdst; 1888 } 1889 } 1890 return WRONG; 1891} 1892 1893time_t 1894mktime(struct tm *tmp) 1895{ 1896 time_t ret; 1897 1898 _THREAD_PRIVATE_MUTEX_LOCK(lcl); 1899 tzset_basic(); 1900 ret = time1(tmp, localsub, 0L); 1901 _THREAD_PRIVATE_MUTEX_UNLOCK(lcl); 1902 return ret; 1903} 1904DEF_STRONG(mktime); 1905 1906#ifdef STD_INSPIRED 1907 1908time_t 1909timelocal(struct tm *tmp) 1910{ 1911 if (tmp != NULL) 1912 tmp->tm_isdst = -1; /* in case it wasn't initialized */ 1913 return mktime(tmp); 1914} 1915 1916time_t 1917timegm(struct tm *tmp) 1918{ 1919 if (tmp != NULL) 1920 tmp->tm_isdst = 0; 1921 return time1(tmp, gmtsub, 0L); 1922} 1923 1924time_t 1925timeoff(struct tm *tmp, long offset) 1926{ 1927 if (tmp != NULL) 1928 tmp->tm_isdst = 0; 1929 return time1(tmp, gmtsub, offset); 1930} 1931 1932#endif /* defined STD_INSPIRED */ 1933 1934/* 1935** XXX--is the below the right way to conditionalize?? 1936*/ 1937 1938#ifdef STD_INSPIRED 1939 1940/* 1941** IEEE Std 1003.1-1988 (POSIX) legislates that 536457599 1942** shall correspond to "Wed Dec 31 23:59:59 UTC 1986", which 1943** is not the case if we are accounting for leap seconds. 1944** So, we provide the following conversion routines for use 1945** when exchanging timestamps with POSIX conforming systems. 1946*/ 1947 1948static long 1949leapcorr(time_t *timep) 1950{ 1951 struct state * sp; 1952 struct lsinfo * lp; 1953 int i; 1954 1955 sp = lclptr; 1956 i = sp->leapcnt; 1957 while (--i >= 0) { 1958 lp = &sp->lsis[i]; 1959 if (*timep >= lp->ls_trans) 1960 return lp->ls_corr; 1961 } 1962 return 0; 1963} 1964 1965time_t 1966time2posix(time_t t) 1967{ 1968 tzset(); 1969 return t - leapcorr(&t); 1970} 1971 1972time_t 1973posix2time(time_t t) 1974{ 1975 time_t x; 1976 time_t y; 1977 1978 tzset(); 1979 /* 1980 ** For a positive leap second hit, the result 1981 ** is not unique. For a negative leap second 1982 ** hit, the corresponding time doesn't exist, 1983 ** so we return an adjacent second. 1984 */ 1985 x = t + leapcorr(&t); 1986 y = x - leapcorr(&x); 1987 if (y < t) { 1988 do { 1989 x++; 1990 y = x - leapcorr(&x); 1991 } while (y < t); 1992 if (t != y) 1993 return x - 1; 1994 } else if (y > t) { 1995 do { 1996 --x; 1997 y = x - leapcorr(&x); 1998 } while (y > t); 1999 if (t != y) 2000 return x + 1; 2001 } 2002 return x; 2003} 2004 2005#endif /* defined STD_INSPIRED */ 2006