1 /* $OpenBSD: localtime.c,v 1.67 2024/08/18 02:20:29 guenther 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 <stdio.h> 17 #include <stdlib.h> 18 #include <string.h> 19 #include <unistd.h> 20 21 #include "private.h" 22 #include "tzfile.h" 23 #include "thread_private.h" 24 25 #ifndef TZ_ABBR_MAX_LEN 26 #define TZ_ABBR_MAX_LEN 16 27 #endif /* !defined TZ_ABBR_MAX_LEN */ 28 29 #ifndef TZ_ABBR_CHAR_SET 30 #define TZ_ABBR_CHAR_SET \ 31 "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789 :+-._" 32 #endif /* !defined TZ_ABBR_CHAR_SET */ 33 34 #ifndef TZ_ABBR_ERR_CHAR 35 #define TZ_ABBR_ERR_CHAR '_' 36 #endif /* !defined TZ_ABBR_ERR_CHAR */ 37 38 #ifndef WILDABBR 39 /* 40 ** Someone might make incorrect use of a time zone abbreviation: 41 ** 1. They might reference tzname[0] before calling tzset (explicitly 42 ** or implicitly). 43 ** 2. They might reference tzname[1] before calling tzset (explicitly 44 ** or implicitly). 45 ** 3. They might reference tzname[1] after setting to a time zone 46 ** in which Daylight Saving Time is never observed. 47 ** 4. They might reference tzname[0] after setting to a time zone 48 ** in which Standard Time is never observed. 49 ** 5. They might reference tm.tm_zone after calling offtime. 50 ** What's best to do in the above cases is open to debate; 51 ** for now, we just set things up so that in any of the five cases 52 ** WILDABBR is used. Another possibility: initialize tzname[0] to the 53 ** string "tzname[0] used before set", and similarly for the other cases. 54 ** And another: initialize tzname[0] to "ERA", with an explanation in the 55 ** manual page of what this "time zone abbreviation" means (doing this so 56 ** that tzname[0] has the "normal" length of three characters). 57 */ 58 #define WILDABBR " " 59 #endif /* !defined WILDABBR */ 60 61 static char wildabbr[] = WILDABBR; 62 63 static const char gmt[] = "GMT"; 64 65 /* 66 ** The DST rules to use if TZ has no rules and we can't load TZDEFRULES. 67 ** We default to US rules as of 1999-08-17. 68 ** POSIX 1003.1 section 8.1.1 says that the default DST rules are 69 ** implementation dependent; for historical reasons, US rules are a 70 ** common default. 71 */ 72 #ifndef TZDEFRULESTRING 73 #define TZDEFRULESTRING ",M4.1.0,M10.5.0" 74 #endif /* !defined TZDEFDST */ 75 76 struct ttinfo { /* time type information */ 77 long tt_gmtoff; /* UTC offset in seconds */ 78 int tt_isdst; /* used to set tm_isdst */ 79 int tt_abbrind; /* abbreviation list index */ 80 int tt_ttisstd; /* TRUE if transition is std time */ 81 int tt_ttisgmt; /* TRUE if transition is UTC */ 82 }; 83 84 struct lsinfo { /* leap second information */ 85 time_t ls_trans; /* transition time */ 86 long ls_corr; /* correction to apply */ 87 }; 88 89 #define BIGGEST(a, b) (((a) > (b)) ? (a) : (b)) 90 91 #ifdef TZNAME_MAX 92 #define MY_TZNAME_MAX TZNAME_MAX 93 #endif /* defined TZNAME_MAX */ 94 #ifndef TZNAME_MAX 95 #define MY_TZNAME_MAX 255 96 #endif /* !defined TZNAME_MAX */ 97 98 struct state { 99 int leapcnt; 100 int timecnt; 101 int typecnt; 102 int charcnt; 103 int goback; 104 int goahead; 105 time_t ats[TZ_MAX_TIMES]; 106 unsigned char types[TZ_MAX_TIMES]; 107 struct ttinfo ttis[TZ_MAX_TYPES]; 108 char chars[BIGGEST(BIGGEST(TZ_MAX_CHARS + 1, sizeof gmt), 109 (2 * (MY_TZNAME_MAX + 1)))]; 110 struct lsinfo lsis[TZ_MAX_LEAPS]; 111 }; 112 113 struct rule { 114 int r_type; /* type of rule--see below */ 115 int r_day; /* day number of rule */ 116 int r_week; /* week number of rule */ 117 int r_mon; /* month number of rule */ 118 long r_time; /* transition time of rule */ 119 }; 120 121 #define JULIAN_DAY 0 /* Jn - Julian day */ 122 #define DAY_OF_YEAR 1 /* n - day of year */ 123 #define MONTH_NTH_DAY_OF_WEEK 2 /* Mm.n.d - month, week, day of week */ 124 125 /* 126 ** Prototypes for static functions. 127 */ 128 129 static long detzcode(const char * codep); 130 static time_t detzcode64(const char * codep); 131 static int differ_by_repeat(time_t t1, time_t t0); 132 static const char * getzname(const char * strp); 133 static const char * getqzname(const char * strp, const int delim); 134 static const char * getnum(const char * strp, int * nump, int min, 135 int max); 136 static const char * getsecs(const char * strp, long * secsp); 137 static const char * getoffset(const char * strp, long * offsetp); 138 static const char * getrule(const char * strp, struct rule * rulep); 139 static void gmtload(struct state * sp); 140 static struct tm * gmtsub(const time_t * timep, long offset, 141 struct tm * tmp); 142 static struct tm * localsub(const time_t * timep, long offset, 143 struct tm * tmp); 144 static int increment_overflow(int * number, int delta); 145 static int leaps_thru_end_of(int y); 146 static int long_increment_overflow(long * number, int delta); 147 static int long_normalize_overflow(long * tensptr, 148 int * unitsptr, int base); 149 static int normalize_overflow(int * tensptr, int * unitsptr, 150 int base); 151 static void settzname(void); 152 static time_t time1(struct tm * tmp, 153 struct tm * (*funcp)(const time_t *, 154 long, struct tm *), 155 long offset); 156 static time_t time2(struct tm *tmp, 157 struct tm * (*funcp)(const time_t *, 158 long, struct tm*), 159 long offset, int * okayp); 160 static time_t time2sub(struct tm *tmp, 161 struct tm * (*funcp)(const time_t *, 162 long, struct tm*), 163 long offset, int * okayp, int do_norm_secs); 164 static struct tm * timesub(const time_t * timep, long offset, 165 const struct state * sp, struct tm * tmp); 166 static int tmcomp(const struct tm * atmp, 167 const struct tm * btmp); 168 static time_t transtime(time_t janfirst, int year, 169 const struct rule * rulep, long offset); 170 static int typesequiv(const struct state * sp, int a, int b); 171 static int tzload(const char * name, struct state * sp, 172 int doextend); 173 static int tzparse(const char * name, struct state * sp, 174 int lastditch); 175 176 #ifdef STD_INSPIRED 177 struct tm *offtime(const time_t *, long); 178 time_t time2posix(time_t); 179 time_t posix2time(time_t); 180 PROTO_DEPRECATED(offtime); 181 PROTO_DEPRECATED(time2posix); 182 PROTO_DEPRECATED(posix2time); 183 #endif 184 185 static struct state * lclptr; 186 static struct state * gmtptr; 187 188 189 #ifndef TZ_STRLEN_MAX 190 #define TZ_STRLEN_MAX 255 191 #endif /* !defined TZ_STRLEN_MAX */ 192 193 static int lcl_is_set; 194 static int gmt_is_set; 195 _THREAD_PRIVATE_MUTEX(lcl); 196 _THREAD_PRIVATE_MUTEX(gmt); 197 198 char * tzname[2] = { 199 wildabbr, 200 wildabbr 201 }; 202 #if 0 203 DEF_WEAK(tzname); 204 #endif 205 206 /* 207 ** Section 4.12.3 of X3.159-1989 requires that 208 ** Except for the strftime function, these functions [asctime, 209 ** ctime, gmtime, localtime] return values in one of two static 210 ** objects: a broken-down time structure and an array of char. 211 ** Thanks to Paul Eggert for noting this. 212 */ 213 214 static struct tm tm; 215 216 long timezone = 0; 217 int daylight = 0; 218 219 static long 220 detzcode(const char *codep) 221 { 222 long result; 223 int i; 224 225 result = (codep[0] & 0x80) ? ~0L : 0; 226 for (i = 0; i < 4; ++i) 227 result = (result << 8) | (codep[i] & 0xff); 228 return result; 229 } 230 231 static time_t 232 detzcode64(const char *codep) 233 { 234 time_t result; 235 int i; 236 237 result = (codep[0] & 0x80) ? (~(int_fast64_t) 0) : 0; 238 for (i = 0; i < 8; ++i) 239 result = result * 256 + (codep[i] & 0xff); 240 return result; 241 } 242 243 static void 244 settzname(void) 245 { 246 struct state * const sp = lclptr; 247 int i; 248 249 tzname[0] = wildabbr; 250 tzname[1] = wildabbr; 251 daylight = 0; 252 timezone = 0; 253 if (sp == NULL) { 254 tzname[0] = tzname[1] = (char *)gmt; 255 return; 256 } 257 /* 258 ** And to get the latest zone names into tzname. . . 259 */ 260 for (i = 0; i < sp->timecnt; ++i) { 261 const struct ttinfo *ttisp = &sp->ttis[sp->types[i]]; 262 263 tzname[ttisp->tt_isdst] = &sp->chars[ttisp->tt_abbrind]; 264 if (ttisp->tt_isdst) 265 daylight = 1; 266 if (!ttisp->tt_isdst) 267 timezone = -(ttisp->tt_gmtoff); 268 } 269 /* 270 ** Finally, scrub the abbreviations. 271 ** First, replace bogus characters. 272 */ 273 for (i = 0; i < sp->charcnt; ++i) { 274 if (strchr(TZ_ABBR_CHAR_SET, sp->chars[i]) == NULL) 275 sp->chars[i] = TZ_ABBR_ERR_CHAR; 276 } 277 /* 278 ** Second, truncate long abbreviations. 279 */ 280 for (i = 0; i < sp->typecnt; ++i) { 281 const struct ttinfo *ttisp = &sp->ttis[i]; 282 char *cp = &sp->chars[ttisp->tt_abbrind]; 283 284 if (strlen(cp) > TZ_ABBR_MAX_LEN && 285 strcmp(cp, GRANDPARENTED) != 0) 286 *(cp + TZ_ABBR_MAX_LEN) = '\0'; 287 } 288 } 289 290 static int 291 differ_by_repeat(time_t t1, time_t t0) 292 { 293 if (TYPE_BIT(time_t) - 1 < SECSPERREPEAT_BITS) 294 return 0; 295 return (int64_t)t1 - t0 == SECSPERREPEAT; 296 } 297 298 static int 299 tzpath_ok(const char *name) 300 { 301 /* Reject absolute paths that don't start with TZDIR. */ 302 if (name[0] == '/' && (strncmp(name, TZDIR, sizeof(TZDIR) - 1) != 0 || 303 name[sizeof(TZDIR) - 1] != '/')) 304 return 0; 305 306 /* Reject paths that contain "../". */ 307 if (strstr(name, "../") != NULL) 308 return 0; 309 310 return 1; 311 } 312 313 static int 314 open_tzfile(const char *name) 315 { 316 char fullname[PATH_MAX]; 317 int i; 318 319 if (name != NULL) { 320 /* 321 * POSIX section 8 says that names starting with a ':' are 322 * "implementation-defined". We treat them as timezone paths. 323 */ 324 if (name[0] == ':') 325 name++; 326 327 /* 328 * Ignore absolute paths that don't start with TZDIR 329 * or that contain "../". 330 */ 331 if (!tzpath_ok(name)) 332 name = NULL; 333 } 334 335 if (name == NULL) { 336 name = TZDEFAULT; 337 } else if (name[0] != '/') { 338 /* Time zone data path is relative to TZDIR. */ 339 i = snprintf(fullname, sizeof(fullname), "%s/%s", TZDIR, name); 340 if (i < 0 || i >= sizeof(fullname)) { 341 errno = ENAMETOOLONG; 342 return -1; 343 } 344 name = fullname; 345 } 346 347 return open(name, O_RDONLY); 348 } 349 350 static int 351 tzload(const char *name, struct state *sp, int doextend) 352 { 353 const char * p; 354 int i; 355 int fid; 356 int stored; 357 int nread; 358 typedef union { 359 struct tzhead tzhead; 360 char buf[2 * sizeof(struct tzhead) + 361 2 * sizeof *sp + 362 4 * TZ_MAX_TIMES]; 363 } u_t; 364 u_t * up; 365 366 up = calloc(1, sizeof *up); 367 if (up == NULL) 368 return -1; 369 370 sp->goback = sp->goahead = FALSE; 371 372 if ((fid = open_tzfile(name)) == -1) { 373 /* Could be a POSIX section 8-style TZ string. */ 374 goto oops; 375 } 376 377 nread = read(fid, up->buf, sizeof up->buf); 378 if (close(fid) == -1 || nread <= 0) 379 goto oops; 380 for (stored = 4; stored <= 8; stored *= 2) { 381 int ttisstdcnt; 382 int ttisgmtcnt; 383 384 ttisstdcnt = (int) detzcode(up->tzhead.tzh_ttisstdcnt); 385 ttisgmtcnt = (int) detzcode(up->tzhead.tzh_ttisgmtcnt); 386 sp->leapcnt = (int) detzcode(up->tzhead.tzh_leapcnt); 387 sp->timecnt = (int) detzcode(up->tzhead.tzh_timecnt); 388 sp->typecnt = (int) detzcode(up->tzhead.tzh_typecnt); 389 sp->charcnt = (int) detzcode(up->tzhead.tzh_charcnt); 390 p = up->tzhead.tzh_charcnt + sizeof up->tzhead.tzh_charcnt; 391 if (sp->leapcnt < 0 || sp->leapcnt > TZ_MAX_LEAPS || 392 sp->typecnt <= 0 || sp->typecnt > TZ_MAX_TYPES || 393 sp->timecnt < 0 || sp->timecnt > TZ_MAX_TIMES || 394 sp->charcnt < 0 || sp->charcnt > TZ_MAX_CHARS || 395 (ttisstdcnt != sp->typecnt && ttisstdcnt != 0) || 396 (ttisgmtcnt != sp->typecnt && ttisgmtcnt != 0)) 397 goto oops; 398 if (nread - (p - up->buf) < 399 sp->timecnt * stored + /* ats */ 400 sp->timecnt + /* types */ 401 sp->typecnt * 6 + /* ttinfos */ 402 sp->charcnt + /* chars */ 403 sp->leapcnt * (stored + 4) + /* lsinfos */ 404 ttisstdcnt + /* ttisstds */ 405 ttisgmtcnt) /* ttisgmts */ 406 goto oops; 407 for (i = 0; i < sp->timecnt; ++i) { 408 sp->ats[i] = (stored == 4) ? 409 detzcode(p) : detzcode64(p); 410 p += stored; 411 } 412 for (i = 0; i < sp->timecnt; ++i) { 413 sp->types[i] = (unsigned char) *p++; 414 if (sp->types[i] >= sp->typecnt) 415 goto oops; 416 } 417 for (i = 0; i < sp->typecnt; ++i) { 418 struct ttinfo * ttisp; 419 420 ttisp = &sp->ttis[i]; 421 ttisp->tt_gmtoff = detzcode(p); 422 p += 4; 423 ttisp->tt_isdst = (unsigned char) *p++; 424 if (ttisp->tt_isdst != 0 && ttisp->tt_isdst != 1) 425 goto oops; 426 ttisp->tt_abbrind = (unsigned char) *p++; 427 if (ttisp->tt_abbrind < 0 || 428 ttisp->tt_abbrind > sp->charcnt) 429 goto oops; 430 } 431 for (i = 0; i < sp->charcnt; ++i) 432 sp->chars[i] = *p++; 433 sp->chars[i] = '\0'; /* ensure '\0' at end */ 434 for (i = 0; i < sp->leapcnt; ++i) { 435 struct lsinfo * lsisp; 436 437 lsisp = &sp->lsis[i]; 438 lsisp->ls_trans = (stored == 4) ? 439 detzcode(p) : detzcode64(p); 440 p += stored; 441 lsisp->ls_corr = detzcode(p); 442 p += 4; 443 } 444 for (i = 0; i < sp->typecnt; ++i) { 445 struct ttinfo * ttisp; 446 447 ttisp = &sp->ttis[i]; 448 if (ttisstdcnt == 0) 449 ttisp->tt_ttisstd = FALSE; 450 else { 451 ttisp->tt_ttisstd = *p++; 452 if (ttisp->tt_ttisstd != TRUE && 453 ttisp->tt_ttisstd != FALSE) 454 goto oops; 455 } 456 } 457 for (i = 0; i < sp->typecnt; ++i) { 458 struct ttinfo * ttisp; 459 460 ttisp = &sp->ttis[i]; 461 if (ttisgmtcnt == 0) 462 ttisp->tt_ttisgmt = FALSE; 463 else { 464 ttisp->tt_ttisgmt = *p++; 465 if (ttisp->tt_ttisgmt != TRUE && 466 ttisp->tt_ttisgmt != FALSE) 467 goto oops; 468 } 469 } 470 /* 471 ** Out-of-sort ats should mean we're running on a 472 ** signed time_t system but using a data file with 473 ** unsigned values (or vice versa). 474 */ 475 for (i = 0; i < sp->timecnt - 2; ++i) 476 if (sp->ats[i] > sp->ats[i + 1]) { 477 ++i; 478 /* 479 ** Ignore the end (easy). 480 */ 481 sp->timecnt = i; 482 break; 483 } 484 /* 485 ** If this is an old file, we're done. 486 */ 487 if (up->tzhead.tzh_version[0] == '\0') 488 break; 489 nread -= p - up->buf; 490 for (i = 0; i < nread; ++i) 491 up->buf[i] = p[i]; 492 /* 493 ** If this is a narrow integer time_t system, we're done. 494 */ 495 if (stored >= sizeof(time_t)) 496 break; 497 } 498 if (doextend && nread > 2 && 499 up->buf[0] == '\n' && up->buf[nread - 1] == '\n' && 500 sp->typecnt + 2 <= TZ_MAX_TYPES) { 501 struct state ts; 502 int result; 503 504 up->buf[nread - 1] = '\0'; 505 result = tzparse(&up->buf[1], &ts, FALSE); 506 if (result == 0 && ts.typecnt == 2 && 507 sp->charcnt + ts.charcnt <= TZ_MAX_CHARS) { 508 for (i = 0; i < 2; ++i) 509 ts.ttis[i].tt_abbrind += 510 sp->charcnt; 511 for (i = 0; i < ts.charcnt; ++i) 512 sp->chars[sp->charcnt++] = 513 ts.chars[i]; 514 i = 0; 515 while (i < ts.timecnt && 516 ts.ats[i] <= 517 sp->ats[sp->timecnt - 1]) 518 ++i; 519 while (i < ts.timecnt && 520 sp->timecnt < TZ_MAX_TIMES) { 521 sp->ats[sp->timecnt] = 522 ts.ats[i]; 523 sp->types[sp->timecnt] = 524 sp->typecnt + 525 ts.types[i]; 526 ++sp->timecnt; 527 ++i; 528 } 529 sp->ttis[sp->typecnt++] = ts.ttis[0]; 530 sp->ttis[sp->typecnt++] = ts.ttis[1]; 531 } 532 } 533 if (sp->timecnt > 1) { 534 for (i = 1; i < sp->timecnt; ++i) { 535 if (typesequiv(sp, sp->types[i], sp->types[0]) && 536 differ_by_repeat(sp->ats[i], sp->ats[0])) { 537 sp->goback = TRUE; 538 break; 539 } 540 } 541 for (i = sp->timecnt - 2; i >= 0; --i) { 542 if (typesequiv(sp, sp->types[sp->timecnt - 1], 543 sp->types[i]) && 544 differ_by_repeat(sp->ats[sp->timecnt - 1], 545 sp->ats[i])) { 546 sp->goahead = TRUE; 547 break; 548 } 549 } 550 } 551 free(up); 552 return 0; 553 oops: 554 free(up); 555 return -1; 556 } 557 558 static int 559 typesequiv(const struct state *sp, int a, int b) 560 { 561 int result; 562 563 if (sp == NULL || 564 a < 0 || a >= sp->typecnt || 565 b < 0 || b >= sp->typecnt) 566 result = FALSE; 567 else { 568 const struct ttinfo * ap = &sp->ttis[a]; 569 const struct ttinfo * bp = &sp->ttis[b]; 570 result = ap->tt_gmtoff == bp->tt_gmtoff && 571 ap->tt_isdst == bp->tt_isdst && 572 ap->tt_ttisstd == bp->tt_ttisstd && 573 ap->tt_ttisgmt == bp->tt_ttisgmt && 574 strcmp(&sp->chars[ap->tt_abbrind], 575 &sp->chars[bp->tt_abbrind]) == 0; 576 } 577 return result; 578 } 579 580 static const int mon_lengths[2][MONSPERYEAR] = { 581 { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }, 582 { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 } 583 }; 584 585 static const int year_lengths[2] = { 586 DAYSPERNYEAR, DAYSPERLYEAR 587 }; 588 589 /* 590 ** Given a pointer into a time zone string, scan until a character that is not 591 ** a valid character in a zone name is found. Return a pointer to that 592 ** character. 593 */ 594 595 static const char * 596 getzname(const char *strp) 597 { 598 char c; 599 600 while ((c = *strp) != '\0' && !isdigit((unsigned char)c) && c != ',' && c != '-' && 601 c != '+') 602 ++strp; 603 return strp; 604 } 605 606 /* 607 ** Given a pointer into an extended time zone string, scan until the ending 608 ** delimiter of the zone name is located. Return a pointer to the delimiter. 609 ** 610 ** As with getzname above, the legal character set is actually quite 611 ** restricted, with other characters producing undefined results. 612 ** We don't do any checking here; checking is done later in common-case code. 613 */ 614 615 static const char * 616 getqzname(const char *strp, const int delim) 617 { 618 int c; 619 620 while ((c = *strp) != '\0' && c != delim) 621 ++strp; 622 return strp; 623 } 624 625 /* 626 ** Given a pointer into a time zone string, extract a number from that string. 627 ** Check that the number is within a specified range; if it is not, return 628 ** NULL. 629 ** Otherwise, return a pointer to the first character not part of the number. 630 */ 631 632 static const char * 633 getnum(const char *strp, int *nump, int min, int max) 634 { 635 char c; 636 int num; 637 638 if (strp == NULL || !isdigit((unsigned char)(c = *strp))) 639 return NULL; 640 num = 0; 641 do { 642 num = num * 10 + (c - '0'); 643 if (num > max) 644 return NULL; /* illegal value */ 645 c = *++strp; 646 } while (isdigit((unsigned char)c)); 647 if (num < min) 648 return NULL; /* illegal value */ 649 *nump = num; 650 return strp; 651 } 652 653 /* 654 ** Given a pointer into a time zone string, extract a number of seconds, 655 ** in hh[:mm[:ss]] form, from the string. 656 ** If any error occurs, return NULL. 657 ** Otherwise, return a pointer to the first character not part of the number 658 ** of seconds. 659 */ 660 661 static const char * 662 getsecs(const char *strp, long *secsp) 663 { 664 int num; 665 666 /* 667 ** `HOURSPERDAY * DAYSPERWEEK - 1' allows quasi-Posix rules like 668 ** "M10.4.6/26", which does not conform to Posix, 669 ** but which specifies the equivalent of 670 ** ``02:00 on the first Sunday on or after 23 Oct''. 671 */ 672 strp = getnum(strp, &num, 0, HOURSPERDAY * DAYSPERWEEK - 1); 673 if (strp == NULL) 674 return NULL; 675 *secsp = num * (long) SECSPERHOUR; 676 if (*strp == ':') { 677 ++strp; 678 strp = getnum(strp, &num, 0, MINSPERHOUR - 1); 679 if (strp == NULL) 680 return NULL; 681 *secsp += num * SECSPERMIN; 682 if (*strp == ':') { 683 ++strp; 684 /* `SECSPERMIN' allows for leap seconds. */ 685 strp = getnum(strp, &num, 0, SECSPERMIN); 686 if (strp == NULL) 687 return NULL; 688 *secsp += num; 689 } 690 } 691 return strp; 692 } 693 694 /* 695 ** Given a pointer into a time zone string, extract an offset, in 696 ** [+-]hh[:mm[:ss]] form, from the string. 697 ** If any error occurs, return NULL. 698 ** Otherwise, return a pointer to the first character not part of the time. 699 */ 700 701 static const char * 702 getoffset(const char *strp, long *offsetp) 703 { 704 int neg = 0; 705 706 if (*strp == '-') { 707 neg = 1; 708 ++strp; 709 } else if (*strp == '+') 710 ++strp; 711 strp = getsecs(strp, offsetp); 712 if (strp == NULL) 713 return NULL; /* illegal time */ 714 if (neg) 715 *offsetp = -*offsetp; 716 return strp; 717 } 718 719 /* 720 ** Given a pointer into a time zone string, extract a rule in the form 721 ** date[/time]. See POSIX section 8 for the format of "date" and "time". 722 ** If a valid rule is not found, return NULL. 723 ** Otherwise, return a pointer to the first character not part of the rule. 724 */ 725 726 static const char * 727 getrule(const char *strp, struct rule *rulep) 728 { 729 if (*strp == 'J') { 730 /* 731 ** Julian day. 732 */ 733 rulep->r_type = JULIAN_DAY; 734 ++strp; 735 strp = getnum(strp, &rulep->r_day, 1, DAYSPERNYEAR); 736 } else if (*strp == 'M') { 737 /* 738 ** Month, week, day. 739 */ 740 rulep->r_type = MONTH_NTH_DAY_OF_WEEK; 741 ++strp; 742 strp = getnum(strp, &rulep->r_mon, 1, MONSPERYEAR); 743 if (strp == NULL) 744 return NULL; 745 if (*strp++ != '.') 746 return NULL; 747 strp = getnum(strp, &rulep->r_week, 1, 5); 748 if (strp == NULL) 749 return NULL; 750 if (*strp++ != '.') 751 return NULL; 752 strp = getnum(strp, &rulep->r_day, 0, DAYSPERWEEK - 1); 753 } else if (isdigit((unsigned char)*strp)) { 754 /* 755 ** Day of year. 756 */ 757 rulep->r_type = DAY_OF_YEAR; 758 strp = getnum(strp, &rulep->r_day, 0, DAYSPERLYEAR - 1); 759 } else 760 return NULL; /* invalid format */ 761 if (strp == NULL) 762 return NULL; 763 if (*strp == '/') { 764 /* 765 ** Time specified. 766 */ 767 ++strp; 768 strp = getsecs(strp, &rulep->r_time); 769 } else 770 rulep->r_time = 2 * SECSPERHOUR; /* default = 2:00:00 */ 771 return strp; 772 } 773 774 /* 775 ** Given the Epoch-relative time of January 1, 00:00:00 UTC, in a year, the 776 ** year, a rule, and the offset from UTC at the time that rule takes effect, 777 ** calculate the Epoch-relative time that rule takes effect. 778 */ 779 780 static time_t 781 transtime(time_t janfirst, int year, const struct rule *rulep, long offset) 782 { 783 int leapyear; 784 time_t value; 785 int i; 786 int d, m1, yy0, yy1, yy2, dow; 787 788 value = 0; 789 leapyear = isleap(year); 790 switch (rulep->r_type) { 791 792 case JULIAN_DAY: 793 /* 794 ** Jn - Julian day, 1 == January 1, 60 == March 1 even in leap 795 ** years. 796 ** In non-leap years, or if the day number is 59 or less, just 797 ** add SECSPERDAY times the day number-1 to the time of 798 ** January 1, midnight, to get the day. 799 */ 800 value = janfirst + (rulep->r_day - 1) * SECSPERDAY; 801 if (leapyear && rulep->r_day >= 60) 802 value += SECSPERDAY; 803 break; 804 805 case DAY_OF_YEAR: 806 /* 807 ** n - day of year. 808 ** Just add SECSPERDAY times the day number to the time of 809 ** January 1, midnight, to get the day. 810 */ 811 value = janfirst + rulep->r_day * SECSPERDAY; 812 break; 813 814 case MONTH_NTH_DAY_OF_WEEK: 815 /* 816 ** Mm.n.d - nth "dth day" of month m. 817 */ 818 value = janfirst; 819 for (i = 0; i < rulep->r_mon - 1; ++i) 820 value += mon_lengths[leapyear][i] * SECSPERDAY; 821 822 /* 823 ** Use Zeller's Congruence to get day-of-week of first day of 824 ** month. 825 */ 826 m1 = (rulep->r_mon + 9) % 12 + 1; 827 yy0 = (rulep->r_mon <= 2) ? (year - 1) : year; 828 yy1 = yy0 / 100; 829 yy2 = yy0 % 100; 830 dow = ((26 * m1 - 2) / 10 + 831 1 + yy2 + yy2 / 4 + yy1 / 4 - 2 * yy1) % 7; 832 if (dow < 0) 833 dow += DAYSPERWEEK; 834 835 /* 836 ** "dow" is the day-of-week of the first day of the month. Get 837 ** the day-of-month (zero-origin) of the first "dow" day of the 838 ** month. 839 */ 840 d = rulep->r_day - dow; 841 if (d < 0) 842 d += DAYSPERWEEK; 843 for (i = 1; i < rulep->r_week; ++i) { 844 if (d + DAYSPERWEEK >= 845 mon_lengths[leapyear][rulep->r_mon - 1]) 846 break; 847 d += DAYSPERWEEK; 848 } 849 850 /* 851 ** "d" is the day-of-month (zero-origin) of the day we want. 852 */ 853 value += d * SECSPERDAY; 854 break; 855 } 856 857 /* 858 ** "value" is the Epoch-relative time of 00:00:00 UTC on the day in 859 ** question. To get the Epoch-relative time of the specified local 860 ** time on that day, add the transition time and the current offset 861 ** from UTC. 862 */ 863 return value + rulep->r_time + offset; 864 } 865 866 /* 867 ** Given a POSIX section 8-style TZ string, fill in the rule tables as 868 ** appropriate. 869 */ 870 871 static int 872 tzparse(const char *name, struct state *sp, int lastditch) 873 { 874 const char * stdname; 875 const char * dstname; 876 size_t stdlen; 877 size_t dstlen; 878 long stdoffset; 879 long dstoffset; 880 time_t * atp; 881 unsigned char * typep; 882 char * cp; 883 int load_result; 884 static struct ttinfo zttinfo; 885 886 dstname = NULL; 887 stdname = name; 888 if (lastditch) { 889 stdlen = strlen(name); /* length of standard zone name */ 890 name += stdlen; 891 if (stdlen >= sizeof sp->chars) 892 stdlen = (sizeof sp->chars) - 1; 893 stdoffset = 0; 894 } else { 895 if (*name == '<') { 896 name++; 897 stdname = name; 898 name = getqzname(name, '>'); 899 if (*name != '>') 900 return (-1); 901 stdlen = name - stdname; 902 name++; 903 } else { 904 name = getzname(name); 905 stdlen = name - stdname; 906 } 907 if (*name == '\0') 908 return -1; 909 name = getoffset(name, &stdoffset); 910 if (name == NULL) 911 return -1; 912 } 913 load_result = tzload(TZDEFRULES, sp, FALSE); 914 if (load_result != 0) 915 sp->leapcnt = 0; /* so, we're off a little */ 916 if (*name != '\0') { 917 if (*name == '<') { 918 dstname = ++name; 919 name = getqzname(name, '>'); 920 if (*name != '>') 921 return -1; 922 dstlen = name - dstname; 923 name++; 924 } else { 925 dstname = name; 926 name = getzname(name); 927 dstlen = name - dstname; /* length of DST zone name */ 928 } 929 if (*name != '\0' && *name != ',' && *name != ';') { 930 name = getoffset(name, &dstoffset); 931 if (name == NULL) 932 return -1; 933 } else 934 dstoffset = stdoffset - SECSPERHOUR; 935 if (*name == '\0' && load_result != 0) 936 name = TZDEFRULESTRING; 937 if (*name == ',' || *name == ';') { 938 struct rule start; 939 struct rule end; 940 int year; 941 time_t janfirst; 942 time_t starttime; 943 time_t endtime; 944 945 ++name; 946 if ((name = getrule(name, &start)) == NULL) 947 return -1; 948 if (*name++ != ',') 949 return -1; 950 if ((name = getrule(name, &end)) == NULL) 951 return -1; 952 if (*name != '\0') 953 return -1; 954 sp->typecnt = 2; /* standard time and DST */ 955 /* 956 ** Two transitions per year, from EPOCH_YEAR forward. 957 */ 958 sp->ttis[0] = sp->ttis[1] = zttinfo; 959 sp->ttis[0].tt_gmtoff = -dstoffset; 960 sp->ttis[0].tt_isdst = 1; 961 sp->ttis[0].tt_abbrind = stdlen + 1; 962 sp->ttis[1].tt_gmtoff = -stdoffset; 963 sp->ttis[1].tt_isdst = 0; 964 sp->ttis[1].tt_abbrind = 0; 965 atp = sp->ats; 966 typep = sp->types; 967 janfirst = 0; 968 sp->timecnt = 0; 969 for (year = EPOCH_YEAR; 970 sp->timecnt + 2 <= TZ_MAX_TIMES; 971 ++year) { 972 time_t newfirst; 973 974 starttime = transtime(janfirst, year, &start, 975 stdoffset); 976 endtime = transtime(janfirst, year, &end, 977 dstoffset); 978 if (starttime > endtime) { 979 *atp++ = endtime; 980 *typep++ = 1; /* DST ends */ 981 *atp++ = starttime; 982 *typep++ = 0; /* DST begins */ 983 } else { 984 *atp++ = starttime; 985 *typep++ = 0; /* DST begins */ 986 *atp++ = endtime; 987 *typep++ = 1; /* DST ends */ 988 } 989 sp->timecnt += 2; 990 newfirst = janfirst; 991 newfirst += year_lengths[isleap(year)] * 992 SECSPERDAY; 993 if (newfirst <= janfirst) 994 break; 995 janfirst = newfirst; 996 } 997 } else { 998 long theirstdoffset; 999 long theirdstoffset; 1000 long theiroffset; 1001 int isdst; 1002 int i; 1003 int j; 1004 1005 if (*name != '\0') 1006 return -1; 1007 /* 1008 ** Initial values of theirstdoffset and theirdstoffset. 1009 */ 1010 theirstdoffset = 0; 1011 for (i = 0; i < sp->timecnt; ++i) { 1012 j = sp->types[i]; 1013 if (!sp->ttis[j].tt_isdst) { 1014 theirstdoffset = 1015 -sp->ttis[j].tt_gmtoff; 1016 break; 1017 } 1018 } 1019 theirdstoffset = 0; 1020 for (i = 0; i < sp->timecnt; ++i) { 1021 j = sp->types[i]; 1022 if (sp->ttis[j].tt_isdst) { 1023 theirdstoffset = 1024 -sp->ttis[j].tt_gmtoff; 1025 break; 1026 } 1027 } 1028 /* 1029 ** Initially we're assumed to be in standard time. 1030 */ 1031 isdst = FALSE; 1032 theiroffset = theirstdoffset; 1033 /* 1034 ** Now juggle transition times and types 1035 ** tracking offsets as you do. 1036 */ 1037 for (i = 0; i < sp->timecnt; ++i) { 1038 j = sp->types[i]; 1039 sp->types[i] = sp->ttis[j].tt_isdst; 1040 if (sp->ttis[j].tt_ttisgmt) { 1041 /* No adjustment to transition time */ 1042 } else { 1043 /* 1044 ** If summer time is in effect, and the 1045 ** transition time was not specified as 1046 ** standard time, add the summer time 1047 ** offset to the transition time; 1048 ** otherwise, add the standard time 1049 ** offset to the transition time. 1050 */ 1051 /* 1052 ** Transitions from DST to DDST 1053 ** will effectively disappear since 1054 ** POSIX provides for only one DST 1055 ** offset. 1056 */ 1057 if (isdst && !sp->ttis[j].tt_ttisstd) { 1058 sp->ats[i] += dstoffset - 1059 theirdstoffset; 1060 } else { 1061 sp->ats[i] += stdoffset - 1062 theirstdoffset; 1063 } 1064 } 1065 theiroffset = -sp->ttis[j].tt_gmtoff; 1066 if (sp->ttis[j].tt_isdst) 1067 theirdstoffset = theiroffset; 1068 else 1069 theirstdoffset = theiroffset; 1070 } 1071 /* 1072 ** Finally, fill in ttis. 1073 */ 1074 sp->ttis[0] = sp->ttis[1] = zttinfo; 1075 sp->ttis[0].tt_gmtoff = -stdoffset; 1076 sp->ttis[0].tt_isdst = FALSE; 1077 sp->ttis[0].tt_abbrind = 0; 1078 sp->ttis[1].tt_gmtoff = -dstoffset; 1079 sp->ttis[1].tt_isdst = TRUE; 1080 sp->ttis[1].tt_abbrind = stdlen + 1; 1081 sp->typecnt = 2; 1082 } 1083 } else { 1084 dstlen = 0; 1085 sp->typecnt = 1; /* only standard time */ 1086 sp->timecnt = 0; 1087 sp->ttis[0] = zttinfo; 1088 sp->ttis[0].tt_gmtoff = -stdoffset; 1089 sp->ttis[0].tt_isdst = 0; 1090 sp->ttis[0].tt_abbrind = 0; 1091 } 1092 sp->charcnt = stdlen + 1; 1093 if (dstlen != 0) 1094 sp->charcnt += dstlen + 1; 1095 if ((size_t) sp->charcnt > sizeof sp->chars) 1096 return -1; 1097 cp = sp->chars; 1098 strlcpy(cp, stdname, stdlen + 1); 1099 cp += stdlen + 1; 1100 if (dstlen != 0) { 1101 strlcpy(cp, dstname, dstlen + 1); 1102 } 1103 return 0; 1104 } 1105 1106 static void 1107 gmtload(struct state *sp) 1108 { 1109 if (tzload(gmt, sp, TRUE) != 0) 1110 (void) tzparse(gmt, sp, TRUE); 1111 } 1112 1113 static void 1114 tzsetwall_basic(void) 1115 { 1116 if (lcl_is_set < 0) 1117 return; 1118 lcl_is_set = -1; 1119 1120 if (lclptr == NULL) { 1121 lclptr = calloc(1, sizeof *lclptr); 1122 if (lclptr == NULL) { 1123 settzname(); /* all we can do */ 1124 return; 1125 } 1126 } 1127 if (tzload(NULL, lclptr, TRUE) != 0) 1128 gmtload(lclptr); 1129 settzname(); 1130 } 1131 1132 #ifndef STD_INSPIRED 1133 /* 1134 ** A non-static declaration of tzsetwall in a system header file 1135 ** may cause a warning about this upcoming static declaration... 1136 */ 1137 static 1138 #endif /* !defined STD_INSPIRED */ 1139 void 1140 tzsetwall(void) 1141 { 1142 _THREAD_PRIVATE_MUTEX_LOCK(lcl); 1143 tzsetwall_basic(); 1144 _THREAD_PRIVATE_MUTEX_UNLOCK(lcl); 1145 } 1146 1147 static void 1148 tzset_basic(void) 1149 { 1150 static char lcl_TZname[TZ_STRLEN_MAX + 1]; 1151 const char * name; 1152 1153 name = getenv("TZ"); 1154 if (name == NULL) { 1155 tzsetwall_basic(); 1156 return; 1157 } 1158 1159 if (lcl_is_set > 0 && strcmp(lcl_TZname, name) == 0) 1160 return; 1161 lcl_is_set = strlen(name) < sizeof lcl_TZname; 1162 if (lcl_is_set) 1163 strlcpy(lcl_TZname, name, sizeof lcl_TZname); 1164 1165 /* Ignore TZ for setuid/setgid processes. */ 1166 if (issetugid()) 1167 name = TZDEFAULT; 1168 1169 if (lclptr == NULL) { 1170 lclptr = calloc(1, sizeof *lclptr); 1171 if (lclptr == NULL) { 1172 settzname(); /* all we can do */ 1173 return; 1174 } 1175 } 1176 if (*name == '\0') { 1177 /* 1178 ** User wants it fast rather than right. 1179 */ 1180 lclptr->leapcnt = 0; /* so, we're off a little */ 1181 lclptr->timecnt = 0; 1182 lclptr->typecnt = 0; 1183 lclptr->ttis[0].tt_isdst = 0; 1184 lclptr->ttis[0].tt_gmtoff = 0; 1185 lclptr->ttis[0].tt_abbrind = 0; 1186 strlcpy(lclptr->chars, gmt, sizeof lclptr->chars); 1187 } else if (tzload(name, lclptr, TRUE) != 0) { 1188 if (name[0] == ':' || tzparse(name, lclptr, FALSE) != 0) 1189 gmtload(lclptr); 1190 } 1191 settzname(); 1192 } 1193 1194 void 1195 tzset(void) 1196 { 1197 _THREAD_PRIVATE_MUTEX_LOCK(lcl); 1198 tzset_basic(); 1199 _THREAD_PRIVATE_MUTEX_UNLOCK(lcl); 1200 } 1201 DEF_WEAK(tzset); 1202 1203 /* 1204 ** The easy way to behave "as if no library function calls" localtime 1205 ** is to not call it--so we drop its guts into "localsub", which can be 1206 ** freely called. (And no, the PANS doesn't require the above behavior-- 1207 ** but it *is* desirable.) 1208 ** 1209 ** The unused offset argument is for the benefit of mktime variants. 1210 */ 1211 1212 static struct tm * 1213 localsub(const time_t *timep, long offset, struct tm *tmp) 1214 { 1215 struct state * sp; 1216 const struct ttinfo * ttisp; 1217 int i; 1218 struct tm * result; 1219 const time_t t = *timep; 1220 1221 sp = lclptr; 1222 if (sp == NULL) 1223 return gmtsub(timep, offset, tmp); 1224 if ((sp->goback && t < sp->ats[0]) || 1225 (sp->goahead && t > sp->ats[sp->timecnt - 1])) { 1226 time_t newt = t; 1227 time_t seconds; 1228 time_t tcycles; 1229 int_fast64_t icycles; 1230 1231 if (t < sp->ats[0]) 1232 seconds = sp->ats[0] - t; 1233 else 1234 seconds = t - sp->ats[sp->timecnt - 1]; 1235 --seconds; 1236 tcycles = seconds / YEARSPERREPEAT / AVGSECSPERYEAR; 1237 ++tcycles; 1238 icycles = tcycles; 1239 if (tcycles - icycles >= 1 || icycles - tcycles >= 1) 1240 return NULL; 1241 seconds = icycles; 1242 seconds *= YEARSPERREPEAT; 1243 seconds *= AVGSECSPERYEAR; 1244 if (t < sp->ats[0]) 1245 newt += seconds; 1246 else 1247 newt -= seconds; 1248 if (newt < sp->ats[0] || 1249 newt > sp->ats[sp->timecnt - 1]) 1250 return NULL; /* "cannot happen" */ 1251 result = localsub(&newt, offset, tmp); 1252 if (result == tmp) { 1253 time_t newy; 1254 1255 newy = tmp->tm_year; 1256 if (t < sp->ats[0]) 1257 newy -= icycles * YEARSPERREPEAT; 1258 else 1259 newy += icycles * YEARSPERREPEAT; 1260 tmp->tm_year = newy; 1261 if (tmp->tm_year != newy) 1262 return NULL; 1263 } 1264 return result; 1265 } 1266 if (sp->timecnt == 0 || t < sp->ats[0]) { 1267 i = 0; 1268 while (sp->ttis[i].tt_isdst) { 1269 if (++i >= sp->typecnt) { 1270 i = 0; 1271 break; 1272 } 1273 } 1274 } else { 1275 int lo = 1; 1276 int hi = sp->timecnt; 1277 1278 while (lo < hi) { 1279 int mid = (lo + hi) >> 1; 1280 1281 if (t < sp->ats[mid]) 1282 hi = mid; 1283 else 1284 lo = mid + 1; 1285 } 1286 i = (int) sp->types[lo - 1]; 1287 } 1288 ttisp = &sp->ttis[i]; 1289 /* 1290 ** To get (wrong) behavior that's compatible with System V Release 2.0 1291 ** you'd replace the statement below with 1292 ** t += ttisp->tt_gmtoff; 1293 ** timesub(&t, 0L, sp, tmp); 1294 */ 1295 result = timesub(&t, ttisp->tt_gmtoff, sp, tmp); 1296 tmp->tm_isdst = ttisp->tt_isdst; 1297 tzname[tmp->tm_isdst] = &sp->chars[ttisp->tt_abbrind]; 1298 tmp->tm_zone = &sp->chars[ttisp->tt_abbrind]; 1299 return result; 1300 } 1301 1302 /* 1303 ** Re-entrant version of localtime. 1304 */ 1305 1306 struct tm * 1307 localtime_r(const time_t *timep, struct tm *p_tm) 1308 { 1309 _THREAD_PRIVATE_MUTEX_LOCK(lcl); 1310 tzset_basic(); 1311 p_tm = localsub(timep, 0L, p_tm); 1312 _THREAD_PRIVATE_MUTEX_UNLOCK(lcl); 1313 return p_tm; 1314 } 1315 DEF_WEAK(localtime_r); 1316 1317 struct tm * 1318 localtime(const time_t *timep) 1319 { 1320 _THREAD_PRIVATE_KEY(localtime); 1321 struct tm * p_tm = (struct tm*)_THREAD_PRIVATE(localtime, tm, NULL); 1322 1323 if (p_tm == NULL) 1324 return NULL; 1325 return localtime_r(timep, p_tm); 1326 } 1327 DEF_STRONG(localtime); 1328 1329 /* 1330 ** gmtsub is to gmtime as localsub is to localtime. 1331 */ 1332 1333 static struct tm * 1334 gmtsub(const time_t *timep, long offset, struct tm *tmp) 1335 { 1336 struct tm * result; 1337 1338 _THREAD_PRIVATE_MUTEX_LOCK(gmt); 1339 if (!gmt_is_set) { 1340 gmt_is_set = TRUE; 1341 gmtptr = calloc(1, sizeof(*gmtptr)); 1342 if (gmtptr != NULL) 1343 gmtload(gmtptr); 1344 } 1345 _THREAD_PRIVATE_MUTEX_UNLOCK(gmt); 1346 result = timesub(timep, offset, gmtptr, tmp); 1347 /* 1348 ** Could get fancy here and deliver something such as 1349 ** "UTC+xxxx" or "UTC-xxxx" if offset is non-zero, 1350 ** but this is no time for a treasure hunt. 1351 */ 1352 if (offset != 0) 1353 tmp->tm_zone = wildabbr; 1354 else { 1355 if (gmtptr == NULL) 1356 tmp->tm_zone = (char *)gmt; 1357 else 1358 tmp->tm_zone = gmtptr->chars; 1359 } 1360 return result; 1361 } 1362 1363 /* 1364 ** Re-entrant version of gmtime. 1365 */ 1366 1367 struct tm * 1368 gmtime_r(const time_t *timep, struct tm *p_tm) 1369 { 1370 return gmtsub(timep, 0L, p_tm); 1371 } 1372 DEF_WEAK(gmtime_r); 1373 1374 struct tm * 1375 gmtime(const time_t *timep) 1376 { 1377 _THREAD_PRIVATE_KEY(gmtime); 1378 struct tm * p_tm = (struct tm*) _THREAD_PRIVATE(gmtime, tm, NULL); 1379 1380 if (p_tm == NULL) 1381 return NULL; 1382 return gmtime_r(timep, p_tm); 1383 1384 } 1385 DEF_WEAK(gmtime); 1386 1387 #ifdef STD_INSPIRED 1388 1389 struct tm * 1390 offtime(const time_t *timep, long offset) 1391 { 1392 return gmtsub(timep, offset, &tm); 1393 } 1394 1395 #endif /* defined STD_INSPIRED */ 1396 1397 /* 1398 ** Return the number of leap years through the end of the given year 1399 ** where, to make the math easy, the answer for year zero is defined as zero. 1400 */ 1401 1402 static int 1403 leaps_thru_end_of(int y) 1404 { 1405 return (y >= 0) ? (y / 4 - y / 100 + y / 400) : 1406 -(leaps_thru_end_of(-(y + 1)) + 1); 1407 } 1408 1409 static struct tm * 1410 timesub(const time_t *timep, long offset, const struct state *sp, struct tm *tmp) 1411 { 1412 const struct lsinfo * lp; 1413 time_t tdays; 1414 int idays; /* unsigned would be so 2003 */ 1415 long rem; 1416 int y; 1417 const int * ip; 1418 long corr; 1419 int hit; 1420 int i; 1421 long seconds; 1422 1423 corr = 0; 1424 hit = 0; 1425 i = (sp == NULL) ? 0 : sp->leapcnt; 1426 while (--i >= 0) { 1427 lp = &sp->lsis[i]; 1428 if (*timep >= lp->ls_trans) { 1429 if (*timep == lp->ls_trans) { 1430 hit = ((i == 0 && lp->ls_corr > 0) || 1431 lp->ls_corr > sp->lsis[i - 1].ls_corr); 1432 if (hit) { 1433 while (i > 0 && 1434 sp->lsis[i].ls_trans == 1435 sp->lsis[i - 1].ls_trans + 1 && 1436 sp->lsis[i].ls_corr == 1437 sp->lsis[i - 1].ls_corr + 1) { 1438 ++hit; 1439 --i; 1440 } 1441 } 1442 } 1443 corr = lp->ls_corr; 1444 break; 1445 } 1446 } 1447 y = EPOCH_YEAR; 1448 tdays = *timep / SECSPERDAY; 1449 rem = *timep - tdays * SECSPERDAY; 1450 while (tdays < 0 || tdays >= year_lengths[isleap(y)]) { 1451 int newy; 1452 time_t tdelta; 1453 int idelta; 1454 int leapdays; 1455 1456 tdelta = tdays / DAYSPERLYEAR; 1457 idelta = tdelta; 1458 if (tdelta - idelta >= 1 || idelta - tdelta >= 1) 1459 return NULL; 1460 if (idelta == 0) 1461 idelta = (tdays < 0) ? -1 : 1; 1462 newy = y; 1463 if (increment_overflow(&newy, idelta)) 1464 return NULL; 1465 leapdays = leaps_thru_end_of(newy - 1) - 1466 leaps_thru_end_of(y - 1); 1467 tdays -= ((time_t) newy - y) * DAYSPERNYEAR; 1468 tdays -= leapdays; 1469 y = newy; 1470 } 1471 1472 seconds = tdays * SECSPERDAY + 0.5; 1473 tdays = seconds / SECSPERDAY; 1474 rem += seconds - tdays * SECSPERDAY; 1475 1476 /* 1477 ** Given the range, we can now fearlessly cast... 1478 */ 1479 idays = tdays; 1480 rem += offset - corr; 1481 while (rem < 0) { 1482 rem += SECSPERDAY; 1483 --idays; 1484 } 1485 while (rem >= SECSPERDAY) { 1486 rem -= SECSPERDAY; 1487 ++idays; 1488 } 1489 while (idays < 0) { 1490 if (increment_overflow(&y, -1)) 1491 return NULL; 1492 idays += year_lengths[isleap(y)]; 1493 } 1494 while (idays >= year_lengths[isleap(y)]) { 1495 idays -= year_lengths[isleap(y)]; 1496 if (increment_overflow(&y, 1)) 1497 return NULL; 1498 } 1499 tmp->tm_year = y; 1500 if (increment_overflow(&tmp->tm_year, -TM_YEAR_BASE)) 1501 return NULL; 1502 tmp->tm_yday = idays; 1503 /* 1504 ** The "extra" mods below avoid overflow problems. 1505 */ 1506 tmp->tm_wday = EPOCH_WDAY + 1507 ((y - EPOCH_YEAR) % DAYSPERWEEK) * 1508 (DAYSPERNYEAR % DAYSPERWEEK) + 1509 leaps_thru_end_of(y - 1) - 1510 leaps_thru_end_of(EPOCH_YEAR - 1) + 1511 idays; 1512 tmp->tm_wday %= DAYSPERWEEK; 1513 if (tmp->tm_wday < 0) 1514 tmp->tm_wday += DAYSPERWEEK; 1515 tmp->tm_hour = (int) (rem / SECSPERHOUR); 1516 rem %= SECSPERHOUR; 1517 tmp->tm_min = (int) (rem / SECSPERMIN); 1518 /* 1519 ** A positive leap second requires a special 1520 ** representation. This uses "... ??:59:60" et seq. 1521 */ 1522 tmp->tm_sec = (int) (rem % SECSPERMIN) + hit; 1523 ip = mon_lengths[isleap(y)]; 1524 for (tmp->tm_mon = 0; idays >= ip[tmp->tm_mon]; ++(tmp->tm_mon)) 1525 idays -= ip[tmp->tm_mon]; 1526 tmp->tm_mday = (int) (idays + 1); 1527 tmp->tm_isdst = 0; 1528 tmp->tm_gmtoff = offset; 1529 return tmp; 1530 } 1531 1532 char * 1533 ctime(const time_t *timep) 1534 { 1535 /* 1536 ** Section 4.12.3.2 of X3.159-1989 requires that 1537 ** The ctime function converts the calendar time pointed to by timer 1538 ** to local time in the form of a string. It is equivalent to 1539 ** asctime(localtime(timer)) 1540 */ 1541 return asctime(localtime(timep)); 1542 } 1543 1544 char * 1545 ctime_r(const time_t *timep, char *buf) 1546 { 1547 struct tm mytm; 1548 1549 return asctime_r(localtime_r(timep, &mytm), buf); 1550 } 1551 1552 /* 1553 ** Adapted from code provided by Robert Elz, who writes: 1554 ** The "best" way to do mktime I think is based on an idea of Bob 1555 ** Kridle's (so its said...) from a long time ago. 1556 ** It does a binary search of the time_t space. Since time_t's are 1557 ** just 32 bits, its a max of 32 iterations (even at 64 bits it 1558 ** would still be very reasonable). 1559 */ 1560 1561 #ifndef WRONG 1562 #define WRONG (-1) 1563 #endif /* !defined WRONG */ 1564 1565 /* 1566 ** Normalize logic courtesy Paul Eggert. 1567 */ 1568 1569 static int 1570 increment_overflow(int *ip, int j) 1571 { 1572 int const i = *ip; 1573 1574 /* 1575 ** If i >= 0 there can only be overflow if i + j > INT_MAX 1576 ** or if j > INT_MAX - i; given i >= 0, INT_MAX - i cannot overflow. 1577 ** If i < 0 there can only be overflow if i + j < INT_MIN 1578 ** or if j < INT_MIN - i; given i < 0, INT_MIN - i cannot overflow. 1579 */ 1580 if ((i >= 0) ? (j > INT_MAX - i) : (j < INT_MIN - i)) 1581 return TRUE; 1582 *ip += j; 1583 return FALSE; 1584 } 1585 1586 static int 1587 long_increment_overflow(long *lp, int m) 1588 { 1589 long const l = *lp; 1590 1591 if ((l >= 0) ? (m > LONG_MAX - l) : (m < LONG_MIN - l)) 1592 return TRUE; 1593 *lp += m; 1594 return FALSE; 1595 } 1596 1597 static int 1598 normalize_overflow(int *tensptr, int *unitsptr, int base) 1599 { 1600 int tensdelta; 1601 1602 tensdelta = (*unitsptr >= 0) ? 1603 (*unitsptr / base) : 1604 (-1 - (-1 - *unitsptr) / base); 1605 *unitsptr -= tensdelta * base; 1606 return increment_overflow(tensptr, tensdelta); 1607 } 1608 1609 static int 1610 long_normalize_overflow(long *tensptr, int *unitsptr, int base) 1611 { 1612 int tensdelta; 1613 1614 tensdelta = (*unitsptr >= 0) ? 1615 (*unitsptr / base) : 1616 (-1 - (-1 - *unitsptr) / base); 1617 *unitsptr -= tensdelta * base; 1618 return long_increment_overflow(tensptr, tensdelta); 1619 } 1620 1621 static int 1622 tmcomp(const struct tm *atmp, const struct tm *btmp) 1623 { 1624 int result; 1625 1626 if ((result = (atmp->tm_year - btmp->tm_year)) == 0 && 1627 (result = (atmp->tm_mon - btmp->tm_mon)) == 0 && 1628 (result = (atmp->tm_mday - btmp->tm_mday)) == 0 && 1629 (result = (atmp->tm_hour - btmp->tm_hour)) == 0 && 1630 (result = (atmp->tm_min - btmp->tm_min)) == 0) 1631 result = atmp->tm_sec - btmp->tm_sec; 1632 return result; 1633 } 1634 1635 static time_t 1636 time2sub(struct tm *tmp, struct tm *(*funcp)(const time_t *, long, struct tm *), 1637 long offset, int *okayp, int do_norm_secs) 1638 { 1639 const struct state * sp; 1640 int dir; 1641 int i, j; 1642 int saved_seconds; 1643 long li; 1644 time_t lo; 1645 time_t hi; 1646 long y; 1647 time_t newt; 1648 time_t t; 1649 struct tm yourtm, mytm; 1650 1651 *okayp = FALSE; 1652 yourtm = *tmp; 1653 if (do_norm_secs) { 1654 if (normalize_overflow(&yourtm.tm_min, &yourtm.tm_sec, 1655 SECSPERMIN)) 1656 return WRONG; 1657 } 1658 if (normalize_overflow(&yourtm.tm_hour, &yourtm.tm_min, MINSPERHOUR)) 1659 return WRONG; 1660 if (normalize_overflow(&yourtm.tm_mday, &yourtm.tm_hour, HOURSPERDAY)) 1661 return WRONG; 1662 y = yourtm.tm_year; 1663 if (long_normalize_overflow(&y, &yourtm.tm_mon, MONSPERYEAR)) 1664 return WRONG; 1665 /* 1666 ** Turn y into an actual year number for now. 1667 ** It is converted back to an offset from TM_YEAR_BASE later. 1668 */ 1669 if (long_increment_overflow(&y, TM_YEAR_BASE)) 1670 return WRONG; 1671 while (yourtm.tm_mday <= 0) { 1672 if (long_increment_overflow(&y, -1)) 1673 return WRONG; 1674 li = y + (1 < yourtm.tm_mon); 1675 yourtm.tm_mday += year_lengths[isleap(li)]; 1676 } 1677 while (yourtm.tm_mday > DAYSPERLYEAR) { 1678 li = y + (1 < yourtm.tm_mon); 1679 yourtm.tm_mday -= year_lengths[isleap(li)]; 1680 if (long_increment_overflow(&y, 1)) 1681 return WRONG; 1682 } 1683 for ( ; ; ) { 1684 i = mon_lengths[isleap(y)][yourtm.tm_mon]; 1685 if (yourtm.tm_mday <= i) 1686 break; 1687 yourtm.tm_mday -= i; 1688 if (++yourtm.tm_mon >= MONSPERYEAR) { 1689 yourtm.tm_mon = 0; 1690 if (long_increment_overflow(&y, 1)) 1691 return WRONG; 1692 } 1693 } 1694 if (long_increment_overflow(&y, -TM_YEAR_BASE)) 1695 return WRONG; 1696 yourtm.tm_year = y; 1697 if (yourtm.tm_year != y) 1698 return WRONG; 1699 if (yourtm.tm_sec >= 0 && yourtm.tm_sec < SECSPERMIN) 1700 saved_seconds = 0; 1701 else if (y + TM_YEAR_BASE < EPOCH_YEAR) { 1702 /* 1703 ** We can't set tm_sec to 0, because that might push the 1704 ** time below the minimum representable time. 1705 ** Set tm_sec to 59 instead. 1706 ** This assumes that the minimum representable time is 1707 ** not in the same minute that a leap second was deleted from, 1708 ** which is a safer assumption than using 58 would be. 1709 */ 1710 if (increment_overflow(&yourtm.tm_sec, 1 - SECSPERMIN)) 1711 return WRONG; 1712 saved_seconds = yourtm.tm_sec; 1713 yourtm.tm_sec = SECSPERMIN - 1; 1714 } else { 1715 saved_seconds = yourtm.tm_sec; 1716 yourtm.tm_sec = 0; 1717 } 1718 /* 1719 ** Do a binary search (this works whatever time_t's type is). 1720 */ 1721 lo = 1; 1722 for (i = 0; i < (int) TYPE_BIT(time_t) - 1; ++i) 1723 lo *= 2; 1724 hi = -(lo + 1); 1725 for ( ; ; ) { 1726 t = lo / 2 + hi / 2; 1727 if (t < lo) 1728 t = lo; 1729 else if (t > hi) 1730 t = hi; 1731 if ((*funcp)(&t, offset, &mytm) == NULL) { 1732 /* 1733 ** Assume that t is too extreme to be represented in 1734 ** a struct tm; arrange things so that it is less 1735 ** extreme on the next pass. 1736 */ 1737 dir = (t > 0) ? 1 : -1; 1738 } else 1739 dir = tmcomp(&mytm, &yourtm); 1740 if (dir != 0) { 1741 if (t == lo) { 1742 ++t; 1743 if (t <= lo) 1744 return WRONG; 1745 ++lo; 1746 } else if (t == hi) { 1747 --t; 1748 if (t >= hi) 1749 return WRONG; 1750 --hi; 1751 } 1752 if (lo > hi) 1753 return WRONG; 1754 if (dir > 0) 1755 hi = t; 1756 else 1757 lo = t; 1758 continue; 1759 } 1760 if (yourtm.tm_isdst < 0 || mytm.tm_isdst == yourtm.tm_isdst) 1761 break; 1762 /* 1763 ** Right time, wrong type. 1764 ** Hunt for right time, right type. 1765 ** It's okay to guess wrong since the guess 1766 ** gets checked. 1767 */ 1768 sp = (const struct state *) 1769 ((funcp == localsub) ? lclptr : gmtptr); 1770 if (sp == NULL) 1771 return WRONG; 1772 for (i = sp->typecnt - 1; i >= 0; --i) { 1773 if (sp->ttis[i].tt_isdst != yourtm.tm_isdst) 1774 continue; 1775 for (j = sp->typecnt - 1; j >= 0; --j) { 1776 if (sp->ttis[j].tt_isdst == yourtm.tm_isdst) 1777 continue; 1778 newt = t + sp->ttis[j].tt_gmtoff - 1779 sp->ttis[i].tt_gmtoff; 1780 if ((*funcp)(&newt, offset, &mytm) == NULL) 1781 continue; 1782 if (tmcomp(&mytm, &yourtm) != 0) 1783 continue; 1784 if (mytm.tm_isdst != yourtm.tm_isdst) 1785 continue; 1786 /* 1787 ** We have a match. 1788 */ 1789 t = newt; 1790 goto label; 1791 } 1792 } 1793 return WRONG; 1794 } 1795 label: 1796 newt = t + saved_seconds; 1797 if ((newt < t) != (saved_seconds < 0)) 1798 return WRONG; 1799 t = newt; 1800 if ((*funcp)(&t, offset, tmp)) 1801 *okayp = TRUE; 1802 return t; 1803 } 1804 1805 static time_t 1806 time2(struct tm *tmp, struct tm * (*funcp)(const time_t *, long, struct tm *), 1807 long offset, int *okayp) 1808 { 1809 time_t t; 1810 1811 /* 1812 ** First try without normalization of seconds 1813 ** (in case tm_sec contains a value associated with a leap second). 1814 ** If that fails, try with normalization of seconds. 1815 */ 1816 t = time2sub(tmp, funcp, offset, okayp, FALSE); 1817 return *okayp ? t : time2sub(tmp, funcp, offset, okayp, TRUE); 1818 } 1819 1820 static time_t 1821 time1(struct tm *tmp, struct tm * (*funcp)(const time_t *, long, struct tm *), 1822 long offset) 1823 { 1824 time_t t; 1825 const struct state * sp; 1826 int samei, otheri; 1827 int sameind, otherind; 1828 int i; 1829 int nseen; 1830 int seen[TZ_MAX_TYPES]; 1831 int types[TZ_MAX_TYPES]; 1832 int okay; 1833 1834 if (tmp == NULL) { 1835 errno = EINVAL; 1836 return WRONG; 1837 } 1838 if (tmp->tm_isdst > 1) 1839 tmp->tm_isdst = 1; 1840 t = time2(tmp, funcp, offset, &okay); 1841 #ifdef PCTS 1842 /* 1843 ** PCTS code courtesy Grant Sullivan. 1844 */ 1845 if (okay) 1846 return t; 1847 if (tmp->tm_isdst < 0) 1848 tmp->tm_isdst = 0; /* reset to std and try again */ 1849 #endif /* defined PCTS */ 1850 #ifndef PCTS 1851 if (okay || tmp->tm_isdst < 0) 1852 return t; 1853 #endif /* !defined PCTS */ 1854 /* 1855 ** We're supposed to assume that somebody took a time of one type 1856 ** and did some math on it that yielded a "struct tm" that's bad. 1857 ** We try to divine the type they started from and adjust to the 1858 ** type they need. 1859 */ 1860 sp = (const struct state *) ((funcp == localsub) ? lclptr : gmtptr); 1861 if (sp == NULL) 1862 return WRONG; 1863 for (i = 0; i < sp->typecnt; ++i) 1864 seen[i] = FALSE; 1865 nseen = 0; 1866 for (i = sp->timecnt - 1; i >= 0; --i) { 1867 if (!seen[sp->types[i]]) { 1868 seen[sp->types[i]] = TRUE; 1869 types[nseen++] = sp->types[i]; 1870 } 1871 } 1872 for (sameind = 0; sameind < nseen; ++sameind) { 1873 samei = types[sameind]; 1874 if (sp->ttis[samei].tt_isdst != tmp->tm_isdst) 1875 continue; 1876 for (otherind = 0; otherind < nseen; ++otherind) { 1877 otheri = types[otherind]; 1878 if (sp->ttis[otheri].tt_isdst == tmp->tm_isdst) 1879 continue; 1880 tmp->tm_sec += sp->ttis[otheri].tt_gmtoff - 1881 sp->ttis[samei].tt_gmtoff; 1882 tmp->tm_isdst = !tmp->tm_isdst; 1883 t = time2(tmp, funcp, offset, &okay); 1884 if (okay) 1885 return t; 1886 tmp->tm_sec -= sp->ttis[otheri].tt_gmtoff - 1887 sp->ttis[samei].tt_gmtoff; 1888 tmp->tm_isdst = !tmp->tm_isdst; 1889 } 1890 } 1891 return WRONG; 1892 } 1893 1894 time_t 1895 mktime(struct tm *tmp) 1896 { 1897 time_t ret; 1898 1899 _THREAD_PRIVATE_MUTEX_LOCK(lcl); 1900 tzset_basic(); 1901 ret = time1(tmp, localsub, 0L); 1902 _THREAD_PRIVATE_MUTEX_UNLOCK(lcl); 1903 return ret; 1904 } 1905 DEF_STRONG(mktime); 1906 1907 #ifdef STD_INSPIRED 1908 1909 time_t 1910 timelocal(struct tm *tmp) 1911 { 1912 if (tmp != NULL) 1913 tmp->tm_isdst = -1; /* in case it wasn't initialized */ 1914 return mktime(tmp); 1915 } 1916 1917 time_t 1918 timegm(struct tm *tmp) 1919 { 1920 if (tmp != NULL) 1921 tmp->tm_isdst = 0; 1922 return time1(tmp, gmtsub, 0L); 1923 } 1924 1925 time_t 1926 timeoff(struct tm *tmp, long offset) 1927 { 1928 if (tmp != NULL) 1929 tmp->tm_isdst = 0; 1930 return time1(tmp, gmtsub, offset); 1931 } 1932 1933 #endif /* defined STD_INSPIRED */ 1934 1935 /* 1936 ** XXX--is the below the right way to conditionalize?? 1937 */ 1938 1939 #ifdef STD_INSPIRED 1940 1941 /* 1942 ** IEEE Std 1003.1-1988 (POSIX) legislates that 536457599 1943 ** shall correspond to "Wed Dec 31 23:59:59 UTC 1986", which 1944 ** is not the case if we are accounting for leap seconds. 1945 ** So, we provide the following conversion routines for use 1946 ** when exchanging timestamps with POSIX conforming systems. 1947 */ 1948 1949 static long 1950 leapcorr(time_t *timep) 1951 { 1952 struct state * sp; 1953 struct lsinfo * lp; 1954 int i; 1955 1956 sp = lclptr; 1957 i = sp->leapcnt; 1958 while (--i >= 0) { 1959 lp = &sp->lsis[i]; 1960 if (*timep >= lp->ls_trans) 1961 return lp->ls_corr; 1962 } 1963 return 0; 1964 } 1965 1966 time_t 1967 time2posix(time_t t) 1968 { 1969 tzset(); 1970 return t - leapcorr(&t); 1971 } 1972 1973 time_t 1974 posix2time(time_t t) 1975 { 1976 time_t x; 1977 time_t y; 1978 1979 tzset(); 1980 /* 1981 ** For a positive leap second hit, the result 1982 ** is not unique. For a negative leap second 1983 ** hit, the corresponding time doesn't exist, 1984 ** so we return an adjacent second. 1985 */ 1986 x = t + leapcorr(&t); 1987 y = x - leapcorr(&x); 1988 if (y < t) { 1989 do { 1990 x++; 1991 y = x - leapcorr(&x); 1992 } while (y < t); 1993 if (t != y) 1994 return x - 1; 1995 } else if (y > t) { 1996 do { 1997 --x; 1998 y = x - leapcorr(&x); 1999 } while (y > t); 2000 if (t != y) 2001 return x + 1; 2002 } 2003 return x; 2004 } 2005 2006 #endif /* defined STD_INSPIRED */ 2007