1 /* 2 ** This file is in the public domain, so clarified as of 3 ** 1996-06-05 by Arthur David Olson. 4 */ 5 6 #ifndef lint 7 #ifndef NOID 8 static char elsieid[] = "@(#)localtime.c 8.9"; 9 #endif /* !defined NOID */ 10 #endif /* !defined lint */ 11 12 /* 13 ** Leap second handling from Bradley White. 14 ** POSIX-style TZ environment variable handling from Guy Harris. 15 */ 16 17 /*LINTLIBRARY*/ 18 19 #include "private.h" 20 #include "tzfile.h" 21 #include "fcntl.h" 22 #include "float.h" /* for FLT_MAX and DBL_MAX */ 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 /* 38 ** SunOS 4.1.1 headers lack O_BINARY. 39 */ 40 41 #ifdef O_BINARY 42 #define OPEN_MODE (O_RDONLY | O_BINARY) 43 #endif /* defined O_BINARY */ 44 #ifndef O_BINARY 45 #define OPEN_MODE O_RDONLY 46 #endif /* !defined O_BINARY */ 47 48 #ifndef WILDABBR 49 /* 50 ** Someone might make incorrect use of a time zone abbreviation: 51 ** 1. They might reference tzname[0] before calling tzset (explicitly 52 ** or implicitly). 53 ** 2. They might reference tzname[1] before calling tzset (explicitly 54 ** or implicitly). 55 ** 3. They might reference tzname[1] after setting to a time zone 56 ** in which Daylight Saving Time is never observed. 57 ** 4. They might reference tzname[0] after setting to a time zone 58 ** in which Standard Time is never observed. 59 ** 5. They might reference tm.TM_ZONE after calling offtime. 60 ** What's best to do in the above cases is open to debate; 61 ** for now, we just set things up so that in any of the five cases 62 ** WILDABBR is used. Another possibility: initialize tzname[0] to the 63 ** string "tzname[0] used before set", and similarly for the other cases. 64 ** And another: initialize tzname[0] to "ERA", with an explanation in the 65 ** manual page of what this "time zone abbreviation" means (doing this so 66 ** that tzname[0] has the "normal" length of three characters). 67 */ 68 #define WILDABBR " " 69 #endif /* !defined WILDABBR */ 70 71 static char wildabbr[] = WILDABBR; 72 73 static const char gmt[] = "GMT"; 74 75 /* 76 ** The DST rules to use if TZ has no rules and we can't load TZDEFRULES. 77 ** We default to US rules as of 1999-08-17. 78 ** POSIX 1003.1 section 8.1.1 says that the default DST rules are 79 ** implementation dependent; for historical reasons, US rules are a 80 ** common default. 81 */ 82 #ifndef TZDEFRULESTRING 83 #define TZDEFRULESTRING ",M4.1.0,M10.5.0" 84 #endif /* !defined TZDEFDST */ 85 86 struct ttinfo { /* time type information */ 87 long tt_gmtoff; /* UTC offset in seconds */ 88 int tt_isdst; /* used to set tm_isdst */ 89 int tt_abbrind; /* abbreviation list index */ 90 int tt_ttisstd; /* TRUE if transition is std time */ 91 int tt_ttisgmt; /* TRUE if transition is UTC */ 92 }; 93 94 struct lsinfo { /* leap second information */ 95 time_t ls_trans; /* transition time */ 96 long ls_corr; /* correction to apply */ 97 }; 98 99 #define BIGGEST(a, b) (((a) > (b)) ? (a) : (b)) 100 101 #ifdef TZNAME_MAX 102 #define MY_TZNAME_MAX TZNAME_MAX 103 #endif /* defined TZNAME_MAX */ 104 #ifndef TZNAME_MAX 105 #define MY_TZNAME_MAX 255 106 #endif /* !defined TZNAME_MAX */ 107 108 struct state { 109 int leapcnt; 110 int timecnt; 111 int typecnt; 112 int charcnt; 113 int goback; 114 int goahead; 115 time_t ats[TZ_MAX_TIMES]; 116 unsigned char types[TZ_MAX_TIMES]; 117 struct ttinfo ttis[TZ_MAX_TYPES]; 118 char chars[BIGGEST(BIGGEST(TZ_MAX_CHARS + 1, sizeof gmt), 119 (2 * (MY_TZNAME_MAX + 1)))]; 120 struct lsinfo lsis[TZ_MAX_LEAPS]; 121 }; 122 123 struct rule { 124 int r_type; /* type of rule--see below */ 125 int r_day; /* day number of rule */ 126 int r_week; /* week number of rule */ 127 int r_mon; /* month number of rule */ 128 long r_time; /* transition time of rule */ 129 }; 130 131 #define JULIAN_DAY 0 /* Jn - Julian day */ 132 #define DAY_OF_YEAR 1 /* n - day of year */ 133 #define MONTH_NTH_DAY_OF_WEEK 2 /* Mm.n.d - month, week, day of week */ 134 135 /* 136 ** Prototypes for static functions. 137 */ 138 139 static long detzcode(const char * codep); 140 static time_t detzcode64(const char * codep); 141 static int differ_by_repeat(time_t t1, time_t t0); 142 static const char * getzname(const char * strp); 143 static const char * getqzname(const char * strp, const int delim); 144 static const char * getnum(const char * strp, int * nump, int min, 145 int max); 146 static const char * getsecs(const char * strp, long * secsp); 147 static const char * getoffset(const char * strp, long * offsetp); 148 static const char * getrule(const char * strp, struct rule * rulep); 149 static void gmtload(struct state * sp); 150 static struct tm * gmtsub(const time_t * timep, long offset, 151 struct tm * tmp); 152 static struct tm * localsub(const time_t * timep, long offset, 153 struct tm * tmp); 154 static int increment_overflow(int * number, int delta); 155 static int leaps_thru_end_of(int y); 156 static int long_increment_overflow(long * number, int delta); 157 static int long_normalize_overflow(long * tensptr, 158 int * unitsptr, int base); 159 static int normalize_overflow(int * tensptr, int * unitsptr, 160 int base); 161 static void settzname(void); 162 static time_t time1(struct tm * tmp, 163 struct tm * (*funcp)(const time_t *, 164 long, struct tm *), 165 long offset); 166 static time_t time2(struct tm *tmp, 167 struct tm * (*funcp)(const time_t *, 168 long, struct tm*), 169 long offset, int * okayp); 170 static time_t time2sub(struct tm *tmp, 171 struct tm * (*funcp)(const time_t *, 172 long, struct tm*), 173 long offset, int * okayp, int do_norm_secs); 174 static struct tm * timesub(const time_t * timep, long offset, 175 const struct state * sp, struct tm * tmp); 176 static int tmcomp(const struct tm * atmp, 177 const struct tm * btmp); 178 static time_t transtime(time_t janfirst, int year, 179 const struct rule * rulep, long offset); 180 static int typesequiv(const struct state * sp, int a, int b); 181 static int tzload(const char * name, struct state * sp, 182 int doextend); 183 static int tzparse(const char * name, struct state * sp, 184 int lastditch); 185 186 #ifdef ALL_STATE 187 static struct state * lclptr; 188 static struct state * gmtptr; 189 #endif /* defined ALL_STATE */ 190 191 #ifndef ALL_STATE 192 static struct state lclmem; 193 static struct state gmtmem; 194 #define lclptr (&lclmem) 195 #define gmtptr (&gmtmem) 196 #endif /* State Farm */ 197 198 #ifndef TZ_STRLEN_MAX 199 #define TZ_STRLEN_MAX 255 200 #endif /* !defined TZ_STRLEN_MAX */ 201 202 static char lcl_TZname[TZ_STRLEN_MAX + 1]; 203 static int lcl_is_set; 204 static int gmt_is_set; 205 206 char * tzname[2] = { 207 wildabbr, 208 wildabbr 209 }; 210 211 /* 212 ** Section 4.12.3 of X3.159-1989 requires that 213 ** Except for the strftime function, these functions [asctime, 214 ** ctime, gmtime, localtime] return values in one of two static 215 ** objects: a broken-down time structure and an array of char. 216 ** Thanks to Paul Eggert for noting this. 217 */ 218 219 static struct tm tm; 220 221 #ifdef USG_COMPAT 222 time_t timezone = 0; 223 int daylight = 0; 224 #endif /* defined USG_COMPAT */ 225 226 #ifdef ALTZONE 227 time_t altzone = 0; 228 #endif /* defined ALTZONE */ 229 230 static long 231 detzcode(codep) 232 const char * const codep; 233 { 234 register long result; 235 register int i; 236 237 result = (codep[0] & 0x80) ? ~0L : 0; 238 for (i = 0; i < 4; ++i) 239 result = (result << 8) | (codep[i] & 0xff); 240 return result; 241 } 242 243 static time_t 244 detzcode64(codep) 245 const char * const codep; 246 { 247 register time_t result; 248 register int i; 249 250 result = (codep[0] & 0x80) ? (~(int_fast64_t) 0) : 0; 251 for (i = 0; i < 8; ++i) 252 result = result * 256 + (codep[i] & 0xff); 253 return result; 254 } 255 256 static void 257 settzname(void) 258 { 259 register struct state * const sp = lclptr; 260 register int i; 261 262 tzname[0] = wildabbr; 263 tzname[1] = wildabbr; 264 #ifdef USG_COMPAT 265 daylight = 0; 266 timezone = 0; 267 #endif /* defined USG_COMPAT */ 268 #ifdef ALTZONE 269 altzone = 0; 270 #endif /* defined ALTZONE */ 271 #ifdef ALL_STATE 272 if (sp == NULL) { 273 tzname[0] = tzname[1] = gmt; 274 return; 275 } 276 #endif /* defined ALL_STATE */ 277 for (i = 0; i < sp->typecnt; ++i) { 278 register const struct ttinfo * const ttisp = &sp->ttis[i]; 279 280 tzname[ttisp->tt_isdst] = 281 &sp->chars[ttisp->tt_abbrind]; 282 #ifdef USG_COMPAT 283 if (ttisp->tt_isdst) 284 daylight = 1; 285 if (i == 0 || !ttisp->tt_isdst) 286 timezone = -(ttisp->tt_gmtoff); 287 #endif /* defined USG_COMPAT */ 288 #ifdef ALTZONE 289 if (i == 0 || ttisp->tt_isdst) 290 altzone = -(ttisp->tt_gmtoff); 291 #endif /* defined ALTZONE */ 292 } 293 /* 294 ** And to get the latest zone names into tzname. . . 295 */ 296 for (i = 0; i < sp->timecnt; ++i) { 297 register const struct ttinfo * const ttisp = 298 &sp->ttis[ 299 sp->types[i]]; 300 301 tzname[ttisp->tt_isdst] = 302 &sp->chars[ttisp->tt_abbrind]; 303 } 304 /* 305 ** Finally, scrub the abbreviations. 306 ** First, replace bogus characters. 307 */ 308 for (i = 0; i < sp->charcnt; ++i) 309 if (strchr(TZ_ABBR_CHAR_SET, sp->chars[i]) == NULL) 310 sp->chars[i] = TZ_ABBR_ERR_CHAR; 311 /* 312 ** Second, truncate long abbreviations. 313 */ 314 for (i = 0; i < sp->typecnt; ++i) { 315 register const struct ttinfo * const ttisp = &sp->ttis[i]; 316 register char * cp = &sp->chars[ttisp->tt_abbrind]; 317 318 if (strlen(cp) > TZ_ABBR_MAX_LEN && 319 strcmp(cp, GRANDPARENTED) != 0) 320 *(cp + TZ_ABBR_MAX_LEN) = '\0'; 321 } 322 } 323 324 static int 325 differ_by_repeat(t1, t0) 326 const time_t t1; 327 const time_t t0; 328 { 329 if (TYPE_INTEGRAL(time_t) && 330 TYPE_BIT(time_t) - TYPE_SIGNED(time_t) < SECSPERREPEAT_BITS) 331 return 0; 332 return t1 - t0 == SECSPERREPEAT; 333 } 334 335 static int 336 tzload(name, sp, doextend) 337 register const char * name; 338 register struct state * const sp; 339 register const int doextend; 340 { 341 register const char * p; 342 register int i; 343 register int fid; 344 register int stored; 345 register int nread; 346 union { 347 struct tzhead tzhead; 348 char buf[2 * sizeof(struct tzhead) + 349 2 * sizeof *sp + 350 4 * TZ_MAX_TIMES]; 351 } u; 352 353 if (name == NULL && (name = TZDEFAULT) == NULL) 354 return -1; 355 { 356 register int doaccess; 357 /* 358 ** Section 4.9.1 of the C standard says that 359 ** "FILENAME_MAX expands to an integral constant expression 360 ** that is the size needed for an array of char large enough 361 ** to hold the longest file name string that the implementation 362 ** guarantees can be opened." 363 */ 364 char fullname[FILENAME_MAX + 1]; 365 366 if (name[0] == ':') 367 ++name; 368 doaccess = name[0] == '/'; 369 if (!doaccess) { 370 if ((p = TZDIR) == NULL) 371 return -1; 372 if ((strlen(p) + strlen(name) + 1) >= sizeof fullname) 373 return -1; 374 (void) strcpy(fullname, p); 375 (void) strcat(fullname, "/"); 376 (void) strcat(fullname, name); 377 /* 378 ** Set doaccess if '.' (as in "../") shows up in name. 379 */ 380 if (strchr(name, '.') != NULL) 381 doaccess = TRUE; 382 name = fullname; 383 } 384 if (doaccess && access(name, R_OK) != 0) 385 return -1; 386 if ((fid = open(name, OPEN_MODE)) == -1) 387 return -1; 388 } 389 nread = read(fid, u.buf, sizeof u.buf); 390 if (close(fid) < 0 || nread <= 0) 391 return -1; 392 for (stored = 4; stored <= 8; stored *= 2) { 393 int ttisstdcnt; 394 int ttisgmtcnt; 395 396 ttisstdcnt = (int) detzcode(u.tzhead.tzh_ttisstdcnt); 397 ttisgmtcnt = (int) detzcode(u.tzhead.tzh_ttisgmtcnt); 398 sp->leapcnt = (int) detzcode(u.tzhead.tzh_leapcnt); 399 sp->timecnt = (int) detzcode(u.tzhead.tzh_timecnt); 400 sp->typecnt = (int) detzcode(u.tzhead.tzh_typecnt); 401 sp->charcnt = (int) detzcode(u.tzhead.tzh_charcnt); 402 p = u.tzhead.tzh_charcnt + sizeof u.tzhead.tzh_charcnt; 403 if (sp->leapcnt < 0 || sp->leapcnt > TZ_MAX_LEAPS || 404 sp->typecnt <= 0 || sp->typecnt > TZ_MAX_TYPES || 405 sp->timecnt < 0 || sp->timecnt > TZ_MAX_TIMES || 406 sp->charcnt < 0 || sp->charcnt > TZ_MAX_CHARS || 407 (ttisstdcnt != sp->typecnt && ttisstdcnt != 0) || 408 (ttisgmtcnt != sp->typecnt && ttisgmtcnt != 0)) 409 return -1; 410 if (nread - (p - u.buf) < 411 sp->timecnt * stored + /* ats */ 412 sp->timecnt + /* types */ 413 sp->typecnt * 6 + /* ttinfos */ 414 sp->charcnt + /* chars */ 415 sp->leapcnt * (stored + 4) + /* lsinfos */ 416 ttisstdcnt + /* ttisstds */ 417 ttisgmtcnt) /* ttisgmts */ 418 return -1; 419 for (i = 0; i < sp->timecnt; ++i) { 420 sp->ats[i] = (stored == 4) ? 421 detzcode(p) : detzcode64(p); 422 p += stored; 423 } 424 for (i = 0; i < sp->timecnt; ++i) { 425 sp->types[i] = (unsigned char) *p++; 426 if (sp->types[i] >= sp->typecnt) 427 return -1; 428 } 429 for (i = 0; i < sp->typecnt; ++i) { 430 register struct ttinfo * ttisp; 431 432 ttisp = &sp->ttis[i]; 433 ttisp->tt_gmtoff = detzcode(p); 434 p += 4; 435 ttisp->tt_isdst = (unsigned char) *p++; 436 if (ttisp->tt_isdst != 0 && ttisp->tt_isdst != 1) 437 return -1; 438 ttisp->tt_abbrind = (unsigned char) *p++; 439 if (ttisp->tt_abbrind < 0 || 440 ttisp->tt_abbrind > sp->charcnt) 441 return -1; 442 } 443 for (i = 0; i < sp->charcnt; ++i) 444 sp->chars[i] = *p++; 445 sp->chars[i] = '\0'; /* ensure '\0' at end */ 446 for (i = 0; i < sp->leapcnt; ++i) { 447 register struct lsinfo * lsisp; 448 449 lsisp = &sp->lsis[i]; 450 lsisp->ls_trans = (stored == 4) ? 451 detzcode(p) : detzcode64(p); 452 p += stored; 453 lsisp->ls_corr = detzcode(p); 454 p += 4; 455 } 456 for (i = 0; i < sp->typecnt; ++i) { 457 register struct ttinfo * ttisp; 458 459 ttisp = &sp->ttis[i]; 460 if (ttisstdcnt == 0) 461 ttisp->tt_ttisstd = FALSE; 462 else { 463 ttisp->tt_ttisstd = *p++; 464 if (ttisp->tt_ttisstd != TRUE && 465 ttisp->tt_ttisstd != FALSE) 466 return -1; 467 } 468 } 469 for (i = 0; i < sp->typecnt; ++i) { 470 register struct ttinfo * ttisp; 471 472 ttisp = &sp->ttis[i]; 473 if (ttisgmtcnt == 0) 474 ttisp->tt_ttisgmt = FALSE; 475 else { 476 ttisp->tt_ttisgmt = *p++; 477 if (ttisp->tt_ttisgmt != TRUE && 478 ttisp->tt_ttisgmt != FALSE) 479 return -1; 480 } 481 } 482 /* 483 ** Out-of-sort ats should mean we're running on a 484 ** signed time_t system but using a data file with 485 ** unsigned values (or vice versa). 486 */ 487 for (i = 0; i < sp->timecnt - 2; ++i) 488 if (sp->ats[i] > sp->ats[i + 1]) { 489 ++i; 490 if (TYPE_SIGNED(time_t)) { 491 /* 492 ** Ignore the end (easy). 493 */ 494 sp->timecnt = i; 495 } else { 496 /* 497 ** Ignore the beginning (harder). 498 */ 499 register int j; 500 501 for (j = 0; j + i < sp->timecnt; ++j) { 502 sp->ats[j] = sp->ats[j + i]; 503 sp->types[j] = sp->types[j + i]; 504 } 505 sp->timecnt = j; 506 } 507 break; 508 } 509 /* 510 ** If this is an old file, we're done. 511 */ 512 if (u.tzhead.tzh_version[0] == '\0') 513 break; 514 nread -= p - u.buf; 515 for (i = 0; i < nread; ++i) 516 u.buf[i] = p[i]; 517 /* 518 ** If this is a narrow integer time_t system, we're done. 519 */ 520 if (stored >= (int) sizeof(time_t) && TYPE_INTEGRAL(time_t)) 521 break; 522 } 523 if (doextend && nread > 2 && 524 u.buf[0] == '\n' && u.buf[nread - 1] == '\n' && 525 sp->typecnt + 2 <= TZ_MAX_TYPES) { 526 struct state ts; 527 register int result; 528 529 u.buf[nread - 1] = '\0'; 530 result = tzparse(&u.buf[1], &ts, FALSE); 531 if (result == 0 && ts.typecnt == 2 && 532 sp->charcnt + ts.charcnt <= TZ_MAX_CHARS) { 533 for (i = 0; i < 2; ++i) 534 ts.ttis[i].tt_abbrind += 535 sp->charcnt; 536 for (i = 0; i < ts.charcnt; ++i) 537 sp->chars[sp->charcnt++] = 538 ts.chars[i]; 539 i = 0; 540 while (i < ts.timecnt && 541 ts.ats[i] <= 542 sp->ats[sp->timecnt - 1]) 543 ++i; 544 while (i < ts.timecnt && 545 sp->timecnt < TZ_MAX_TIMES) { 546 sp->ats[sp->timecnt] = 547 ts.ats[i]; 548 sp->types[sp->timecnt] = 549 sp->typecnt + 550 ts.types[i]; 551 ++sp->timecnt; 552 ++i; 553 } 554 sp->ttis[sp->typecnt++] = ts.ttis[0]; 555 sp->ttis[sp->typecnt++] = ts.ttis[1]; 556 } 557 } 558 sp->goback = sp->goahead = FALSE; 559 if (sp->timecnt > 1) { 560 for (i = 1; i < sp->timecnt; ++i) 561 if (typesequiv(sp, sp->types[i], sp->types[0]) && 562 differ_by_repeat(sp->ats[i], sp->ats[0])) { 563 sp->goback = TRUE; 564 break; 565 } 566 for (i = sp->timecnt - 2; i >= 0; --i) 567 if (typesequiv(sp, sp->types[sp->timecnt - 1], 568 sp->types[i]) && 569 differ_by_repeat(sp->ats[sp->timecnt - 1], 570 sp->ats[i])) { 571 sp->goahead = TRUE; 572 break; 573 } 574 } 575 return 0; 576 } 577 578 static int 579 typesequiv(sp, a, b) 580 const struct state * const sp; 581 const int a; 582 const int b; 583 { 584 register int result; 585 586 if (sp == NULL || 587 a < 0 || a >= sp->typecnt || 588 b < 0 || b >= sp->typecnt) 589 result = FALSE; 590 else { 591 register const struct ttinfo * ap = &sp->ttis[a]; 592 register const struct ttinfo * bp = &sp->ttis[b]; 593 result = ap->tt_gmtoff == bp->tt_gmtoff && 594 ap->tt_isdst == bp->tt_isdst && 595 ap->tt_ttisstd == bp->tt_ttisstd && 596 ap->tt_ttisgmt == bp->tt_ttisgmt && 597 strcmp(&sp->chars[ap->tt_abbrind], 598 &sp->chars[bp->tt_abbrind]) == 0; 599 } 600 return result; 601 } 602 603 static const int mon_lengths[2][MONSPERYEAR] = { 604 { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }, 605 { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 } 606 }; 607 608 static const int year_lengths[2] = { 609 DAYSPERNYEAR, DAYSPERLYEAR 610 }; 611 612 /* 613 ** Given a pointer into a time zone string, scan until a character that is not 614 ** a valid character in a zone name is found. Return a pointer to that 615 ** character. 616 */ 617 618 static const char * 619 getzname(strp) 620 register const char * strp; 621 { 622 register char c; 623 624 while ((c = *strp) != '\0' && !is_digit(c) && c != ',' && c != '-' && 625 c != '+') 626 ++strp; 627 return strp; 628 } 629 630 /* 631 ** Given a pointer into an extended time zone string, scan until the ending 632 ** delimiter of the zone name is located. Return a pointer to the delimiter. 633 ** 634 ** As with getzname above, the legal character set is actually quite 635 ** restricted, with other characters producing undefined results. 636 ** We don't do any checking here; checking is done later in common-case code. 637 */ 638 639 static const char * 640 getqzname(register const char *strp, const int delim) 641 { 642 register int c; 643 644 while ((c = *strp) != '\0' && c != delim) 645 ++strp; 646 return strp; 647 } 648 649 /* 650 ** Given a pointer into a time zone string, extract a number from that string. 651 ** Check that the number is within a specified range; if it is not, return 652 ** NULL. 653 ** Otherwise, return a pointer to the first character not part of the number. 654 */ 655 656 static const char * 657 getnum(strp, nump, min, max) 658 register const char * strp; 659 int * const nump; 660 const int min; 661 const int max; 662 { 663 register char c; 664 register int num; 665 666 if (strp == NULL || !is_digit(c = *strp)) 667 return NULL; 668 num = 0; 669 do { 670 num = num * 10 + (c - '0'); 671 if (num > max) 672 return NULL; /* illegal value */ 673 c = *++strp; 674 } while (is_digit(c)); 675 if (num < min) 676 return NULL; /* illegal value */ 677 *nump = num; 678 return strp; 679 } 680 681 /* 682 ** Given a pointer into a time zone string, extract a number of seconds, 683 ** in hh[:mm[:ss]] form, from the string. 684 ** If any error occurs, return NULL. 685 ** Otherwise, return a pointer to the first character not part of the number 686 ** of seconds. 687 */ 688 689 static const char * 690 getsecs(strp, secsp) 691 register const char * strp; 692 long * const secsp; 693 { 694 int num; 695 696 /* 697 ** `HOURSPERDAY * DAYSPERWEEK - 1' allows quasi-Posix rules like 698 ** "M10.4.6/26", which does not conform to Posix, 699 ** but which specifies the equivalent of 700 ** ``02:00 on the first Sunday on or after 23 Oct''. 701 */ 702 strp = getnum(strp, &num, 0, HOURSPERDAY * DAYSPERWEEK - 1); 703 if (strp == NULL) 704 return NULL; 705 *secsp = num * (long) SECSPERHOUR; 706 if (*strp == ':') { 707 ++strp; 708 strp = getnum(strp, &num, 0, MINSPERHOUR - 1); 709 if (strp == NULL) 710 return NULL; 711 *secsp += num * SECSPERMIN; 712 if (*strp == ':') { 713 ++strp; 714 /* `SECSPERMIN' allows for leap seconds. */ 715 strp = getnum(strp, &num, 0, SECSPERMIN); 716 if (strp == NULL) 717 return NULL; 718 *secsp += num; 719 } 720 } 721 return strp; 722 } 723 724 /* 725 ** Given a pointer into a time zone string, extract an offset, in 726 ** [+-]hh[:mm[:ss]] form, from the string. 727 ** If any error occurs, return NULL. 728 ** Otherwise, return a pointer to the first character not part of the time. 729 */ 730 731 static const char * 732 getoffset(strp, offsetp) 733 register const char * strp; 734 long * const offsetp; 735 { 736 register int neg = 0; 737 738 if (*strp == '-') { 739 neg = 1; 740 ++strp; 741 } else if (*strp == '+') 742 ++strp; 743 strp = getsecs(strp, offsetp); 744 if (strp == NULL) 745 return NULL; /* illegal time */ 746 if (neg) 747 *offsetp = -*offsetp; 748 return strp; 749 } 750 751 /* 752 ** Given a pointer into a time zone string, extract a rule in the form 753 ** date[/time]. See POSIX section 8 for the format of "date" and "time". 754 ** If a valid rule is not found, return NULL. 755 ** Otherwise, return a pointer to the first character not part of the rule. 756 */ 757 758 static const char * 759 getrule(strp, rulep) 760 const char * strp; 761 register struct rule * const rulep; 762 { 763 if (*strp == 'J') { 764 /* 765 ** Julian day. 766 */ 767 rulep->r_type = JULIAN_DAY; 768 ++strp; 769 strp = getnum(strp, &rulep->r_day, 1, DAYSPERNYEAR); 770 } else if (*strp == 'M') { 771 /* 772 ** Month, week, day. 773 */ 774 rulep->r_type = MONTH_NTH_DAY_OF_WEEK; 775 ++strp; 776 strp = getnum(strp, &rulep->r_mon, 1, MONSPERYEAR); 777 if (strp == NULL) 778 return NULL; 779 if (*strp++ != '.') 780 return NULL; 781 strp = getnum(strp, &rulep->r_week, 1, 5); 782 if (strp == NULL) 783 return NULL; 784 if (*strp++ != '.') 785 return NULL; 786 strp = getnum(strp, &rulep->r_day, 0, DAYSPERWEEK - 1); 787 } else if (is_digit(*strp)) { 788 /* 789 ** Day of year. 790 */ 791 rulep->r_type = DAY_OF_YEAR; 792 strp = getnum(strp, &rulep->r_day, 0, DAYSPERLYEAR - 1); 793 } else return NULL; /* invalid format */ 794 if (strp == NULL) 795 return NULL; 796 if (*strp == '/') { 797 /* 798 ** Time specified. 799 */ 800 ++strp; 801 strp = getsecs(strp, &rulep->r_time); 802 } else rulep->r_time = 2 * SECSPERHOUR; /* default = 2:00:00 */ 803 return strp; 804 } 805 806 /* 807 ** Given the Epoch-relative time of January 1, 00:00:00 UTC, in a year, the 808 ** year, a rule, and the offset from UTC at the time that rule takes effect, 809 ** calculate the Epoch-relative time that rule takes effect. 810 */ 811 812 static time_t 813 transtime(janfirst, year, rulep, offset) 814 const time_t janfirst; 815 const int year; 816 register const struct rule * const rulep; 817 const long offset; 818 { 819 register int leapyear; 820 register time_t value; 821 register int i; 822 int d, m1, yy0, yy1, yy2, dow; 823 824 INITIALIZE(value); 825 leapyear = isleap(year); 826 switch (rulep->r_type) { 827 828 case JULIAN_DAY: 829 /* 830 ** Jn - Julian day, 1 == January 1, 60 == March 1 even in leap 831 ** years. 832 ** In non-leap years, or if the day number is 59 or less, just 833 ** add SECSPERDAY times the day number-1 to the time of 834 ** January 1, midnight, to get the day. 835 */ 836 value = janfirst + (rulep->r_day - 1) * SECSPERDAY; 837 if (leapyear && rulep->r_day >= 60) 838 value += SECSPERDAY; 839 break; 840 841 case DAY_OF_YEAR: 842 /* 843 ** n - day of year. 844 ** Just add SECSPERDAY times the day number to the time of 845 ** January 1, midnight, to get the day. 846 */ 847 value = janfirst + rulep->r_day * SECSPERDAY; 848 break; 849 850 case MONTH_NTH_DAY_OF_WEEK: 851 /* 852 ** Mm.n.d - nth "dth day" of month m. 853 */ 854 value = janfirst; 855 for (i = 0; i < rulep->r_mon - 1; ++i) 856 value += mon_lengths[leapyear][i] * SECSPERDAY; 857 858 /* 859 ** Use Zeller's Congruence to get day-of-week of first day of 860 ** month. 861 */ 862 m1 = (rulep->r_mon + 9) % 12 + 1; 863 yy0 = (rulep->r_mon <= 2) ? (year - 1) : year; 864 yy1 = yy0 / 100; 865 yy2 = yy0 % 100; 866 dow = ((26 * m1 - 2) / 10 + 867 1 + yy2 + yy2 / 4 + yy1 / 4 - 2 * yy1) % 7; 868 if (dow < 0) 869 dow += DAYSPERWEEK; 870 871 /* 872 ** "dow" is the day-of-week of the first day of the month. Get 873 ** the day-of-month (zero-origin) of the first "dow" day of the 874 ** month. 875 */ 876 d = rulep->r_day - dow; 877 if (d < 0) 878 d += DAYSPERWEEK; 879 for (i = 1; i < rulep->r_week; ++i) { 880 if (d + DAYSPERWEEK >= 881 mon_lengths[leapyear][rulep->r_mon - 1]) 882 break; 883 d += DAYSPERWEEK; 884 } 885 886 /* 887 ** "d" is the day-of-month (zero-origin) of the day we want. 888 */ 889 value += d * SECSPERDAY; 890 break; 891 } 892 893 /* 894 ** "value" is the Epoch-relative time of 00:00:00 UTC on the day in 895 ** question. To get the Epoch-relative time of the specified local 896 ** time on that day, add the transition time and the current offset 897 ** from UTC. 898 */ 899 return value + rulep->r_time + offset; 900 } 901 902 /* 903 ** Given a POSIX section 8-style TZ string, fill in the rule tables as 904 ** appropriate. 905 */ 906 907 static int 908 tzparse(name, sp, lastditch) 909 const char * name; 910 register struct state * const sp; 911 const int lastditch; 912 { 913 const char * stdname; 914 const char * dstname; 915 size_t stdlen; 916 size_t dstlen; 917 long stdoffset; 918 long dstoffset; 919 register time_t * atp; 920 register unsigned char * typep; 921 register char * cp; 922 register int load_result; 923 924 INITIALIZE(dstname); 925 stdname = name; 926 if (lastditch) { 927 stdlen = strlen(name); /* length of standard zone name */ 928 name += stdlen; 929 if (stdlen >= sizeof sp->chars) 930 stdlen = (sizeof sp->chars) - 1; 931 stdoffset = 0; 932 } else { 933 if (*name == '<') { 934 name++; 935 stdname = name; 936 name = getqzname(name, '>'); 937 if (*name != '>') 938 return (-1); 939 stdlen = name - stdname; 940 name++; 941 } else { 942 name = getzname(name); 943 stdlen = name - stdname; 944 } 945 if (*name == '\0') 946 return -1; 947 name = getoffset(name, &stdoffset); 948 if (name == NULL) 949 return -1; 950 } 951 load_result = tzload(TZDEFRULES, sp, FALSE); 952 if (load_result != 0) 953 sp->leapcnt = 0; /* so, we're off a little */ 954 if (*name != '\0') { 955 if (*name == '<') { 956 dstname = ++name; 957 name = getqzname(name, '>'); 958 if (*name != '>') 959 return -1; 960 dstlen = name - dstname; 961 name++; 962 } else { 963 dstname = name; 964 name = getzname(name); 965 dstlen = name - dstname; /* length of DST zone name */ 966 } 967 if (*name != '\0' && *name != ',' && *name != ';') { 968 name = getoffset(name, &dstoffset); 969 if (name == NULL) 970 return -1; 971 } else dstoffset = stdoffset - SECSPERHOUR; 972 if (*name == '\0' && load_result != 0) 973 name = TZDEFRULESTRING; 974 if (*name == ',' || *name == ';') { 975 struct rule start; 976 struct rule end; 977 register int year; 978 register time_t janfirst; 979 time_t starttime; 980 time_t endtime; 981 982 ++name; 983 if ((name = getrule(name, &start)) == NULL) 984 return -1; 985 if (*name++ != ',') 986 return -1; 987 if ((name = getrule(name, &end)) == NULL) 988 return -1; 989 if (*name != '\0') 990 return -1; 991 sp->typecnt = 2; /* standard time and DST */ 992 /* 993 ** Two transitions per year, from EPOCH_YEAR forward. 994 */ 995 sp->ttis[0].tt_gmtoff = -dstoffset; 996 sp->ttis[0].tt_isdst = 1; 997 sp->ttis[0].tt_abbrind = stdlen + 1; 998 sp->ttis[1].tt_gmtoff = -stdoffset; 999 sp->ttis[1].tt_isdst = 0; 1000 sp->ttis[1].tt_abbrind = 0; 1001 atp = sp->ats; 1002 typep = sp->types; 1003 janfirst = 0; 1004 sp->timecnt = 0; 1005 for (year = EPOCH_YEAR; 1006 sp->timecnt + 2 <= TZ_MAX_TIMES; 1007 ++year) { 1008 time_t newfirst; 1009 1010 starttime = transtime(janfirst, year, &start, 1011 stdoffset); 1012 endtime = transtime(janfirst, year, &end, 1013 dstoffset); 1014 if (starttime > endtime) { 1015 *atp++ = endtime; 1016 *typep++ = 1; /* DST ends */ 1017 *atp++ = starttime; 1018 *typep++ = 0; /* DST begins */ 1019 } else { 1020 *atp++ = starttime; 1021 *typep++ = 0; /* DST begins */ 1022 *atp++ = endtime; 1023 *typep++ = 1; /* DST ends */ 1024 } 1025 sp->timecnt += 2; 1026 newfirst = janfirst; 1027 newfirst += year_lengths[isleap(year)] * 1028 SECSPERDAY; 1029 if (newfirst <= janfirst) 1030 break; 1031 janfirst = newfirst; 1032 } 1033 } else { 1034 register long theirstdoffset; 1035 register long theirdstoffset; 1036 register long theiroffset; 1037 register int isdst; 1038 register int i; 1039 register int j; 1040 1041 if (*name != '\0') 1042 return -1; 1043 /* 1044 ** Initial values of theirstdoffset and theirdstoffset. 1045 */ 1046 theirstdoffset = 0; 1047 for (i = 0; i < sp->timecnt; ++i) { 1048 j = sp->types[i]; 1049 if (!sp->ttis[j].tt_isdst) { 1050 theirstdoffset = 1051 -sp->ttis[j].tt_gmtoff; 1052 break; 1053 } 1054 } 1055 theirdstoffset = 0; 1056 for (i = 0; i < sp->timecnt; ++i) { 1057 j = sp->types[i]; 1058 if (sp->ttis[j].tt_isdst) { 1059 theirdstoffset = 1060 -sp->ttis[j].tt_gmtoff; 1061 break; 1062 } 1063 } 1064 /* 1065 ** Initially we're assumed to be in standard time. 1066 */ 1067 isdst = FALSE; 1068 theiroffset = theirstdoffset; 1069 /* 1070 ** Now juggle transition times and types 1071 ** tracking offsets as you do. 1072 */ 1073 for (i = 0; i < sp->timecnt; ++i) { 1074 j = sp->types[i]; 1075 sp->types[i] = sp->ttis[j].tt_isdst; 1076 if (sp->ttis[j].tt_ttisgmt) { 1077 /* No adjustment to transition time */ 1078 } else { 1079 /* 1080 ** If summer time is in effect, and the 1081 ** transition time was not specified as 1082 ** standard time, add the summer time 1083 ** offset to the transition time; 1084 ** otherwise, add the standard time 1085 ** offset to the transition time. 1086 */ 1087 /* 1088 ** Transitions from DST to DDST 1089 ** will effectively disappear since 1090 ** POSIX provides for only one DST 1091 ** offset. 1092 */ 1093 if (isdst && !sp->ttis[j].tt_ttisstd) { 1094 sp->ats[i] += dstoffset - 1095 theirdstoffset; 1096 } else { 1097 sp->ats[i] += stdoffset - 1098 theirstdoffset; 1099 } 1100 } 1101 theiroffset = -sp->ttis[j].tt_gmtoff; 1102 if (sp->ttis[j].tt_isdst) 1103 theirdstoffset = theiroffset; 1104 else theirstdoffset = theiroffset; 1105 } 1106 /* 1107 ** Finally, fill in ttis. 1108 ** ttisstd and ttisgmt need not be handled. 1109 */ 1110 sp->ttis[0].tt_gmtoff = -stdoffset; 1111 sp->ttis[0].tt_isdst = FALSE; 1112 sp->ttis[0].tt_abbrind = 0; 1113 sp->ttis[1].tt_gmtoff = -dstoffset; 1114 sp->ttis[1].tt_isdst = TRUE; 1115 sp->ttis[1].tt_abbrind = stdlen + 1; 1116 sp->typecnt = 2; 1117 } 1118 } else { 1119 dstlen = 0; 1120 sp->typecnt = 1; /* only standard time */ 1121 sp->timecnt = 0; 1122 sp->ttis[0].tt_gmtoff = -stdoffset; 1123 sp->ttis[0].tt_isdst = 0; 1124 sp->ttis[0].tt_abbrind = 0; 1125 } 1126 sp->charcnt = stdlen + 1; 1127 if (dstlen != 0) 1128 sp->charcnt += dstlen + 1; 1129 if ((size_t) sp->charcnt > sizeof sp->chars) 1130 return -1; 1131 cp = sp->chars; 1132 (void) strncpy(cp, stdname, stdlen); 1133 cp += stdlen; 1134 *cp++ = '\0'; 1135 if (dstlen != 0) { 1136 (void) strncpy(cp, dstname, dstlen); 1137 *(cp + dstlen) = '\0'; 1138 } 1139 return 0; 1140 } 1141 1142 static void 1143 gmtload(sp) 1144 struct state * const sp; 1145 { 1146 if (tzload(gmt, sp, TRUE) != 0) 1147 (void) tzparse(gmt, sp, TRUE); 1148 } 1149 1150 #ifndef STD_INSPIRED 1151 /* 1152 ** A non-static declaration of tzsetwall in a system header file 1153 ** may cause a warning about this upcoming static declaration... 1154 */ 1155 static 1156 #endif /* !defined STD_INSPIRED */ 1157 void 1158 tzsetwall(void) 1159 { 1160 if (lcl_is_set < 0) 1161 return; 1162 lcl_is_set = -1; 1163 1164 #ifdef ALL_STATE 1165 if (lclptr == NULL) { 1166 lclptr = (struct state *) malloc(sizeof *lclptr); 1167 if (lclptr == NULL) { 1168 settzname(); /* all we can do */ 1169 return; 1170 } 1171 } 1172 #endif /* defined ALL_STATE */ 1173 if (tzload((char *) NULL, lclptr, TRUE) != 0) 1174 gmtload(lclptr); 1175 settzname(); 1176 } 1177 1178 void 1179 tzset(void) 1180 { 1181 register const char * name; 1182 1183 name = getenv("TZ"); 1184 if (name == NULL) { 1185 tzsetwall(); 1186 return; 1187 } 1188 1189 if (lcl_is_set > 0 && strcmp(lcl_TZname, name) == 0) 1190 return; 1191 lcl_is_set = strlen(name) < sizeof lcl_TZname; 1192 if (lcl_is_set) 1193 (void) strcpy(lcl_TZname, name); 1194 1195 #ifdef ALL_STATE 1196 if (lclptr == NULL) { 1197 lclptr = (struct state *) malloc(sizeof *lclptr); 1198 if (lclptr == NULL) { 1199 settzname(); /* all we can do */ 1200 return; 1201 } 1202 } 1203 #endif /* defined ALL_STATE */ 1204 if (*name == '\0') { 1205 /* 1206 ** User wants it fast rather than right. 1207 */ 1208 lclptr->leapcnt = 0; /* so, we're off a little */ 1209 lclptr->timecnt = 0; 1210 lclptr->typecnt = 0; 1211 lclptr->ttis[0].tt_isdst = 0; 1212 lclptr->ttis[0].tt_gmtoff = 0; 1213 lclptr->ttis[0].tt_abbrind = 0; 1214 (void) strcpy(lclptr->chars, gmt); 1215 } else if (tzload(name, lclptr, TRUE) != 0) 1216 if (name[0] == ':' || tzparse(name, lclptr, FALSE) != 0) 1217 (void) gmtload(lclptr); 1218 settzname(); 1219 } 1220 1221 /* 1222 ** The easy way to behave "as if no library function calls" localtime 1223 ** is to not call it--so we drop its guts into "localsub", which can be 1224 ** freely called. (And no, the PANS doesn't require the above behavior-- 1225 ** but it *is* desirable.) 1226 ** 1227 ** The unused offset argument is for the benefit of mktime variants. 1228 */ 1229 1230 /*ARGSUSED*/ 1231 static struct tm * 1232 localsub(timep, offset, tmp) 1233 const time_t * const timep; 1234 const long offset; 1235 struct tm * const tmp; 1236 { 1237 register struct state * sp; 1238 register const struct ttinfo * ttisp; 1239 register int i; 1240 register struct tm * result; 1241 const time_t t = *timep; 1242 1243 sp = lclptr; 1244 #ifdef ALL_STATE 1245 if (sp == NULL) 1246 return gmtsub(timep, offset, tmp); 1247 #endif /* defined ALL_STATE */ 1248 if ((sp->goback && t < sp->ats[0]) || 1249 (sp->goahead && t > sp->ats[sp->timecnt - 1])) { 1250 time_t newt = t; 1251 register time_t seconds; 1252 register time_t tcycles; 1253 register int_fast64_t icycles; 1254 1255 if (t < sp->ats[0]) 1256 seconds = sp->ats[0] - t; 1257 else seconds = t - sp->ats[sp->timecnt - 1]; 1258 --seconds; 1259 tcycles = seconds / YEARSPERREPEAT / AVGSECSPERYEAR; 1260 ++tcycles; 1261 icycles = tcycles; 1262 if (tcycles - icycles >= 1 || icycles - tcycles >= 1) 1263 return NULL; 1264 seconds = icycles; 1265 seconds *= YEARSPERREPEAT; 1266 seconds *= AVGSECSPERYEAR; 1267 if (t < sp->ats[0]) 1268 newt += seconds; 1269 else newt -= seconds; 1270 if (newt < sp->ats[0] || 1271 newt > sp->ats[sp->timecnt - 1]) 1272 return NULL; /* "cannot happen" */ 1273 result = localsub(&newt, offset, tmp); 1274 if (result == tmp) { 1275 register time_t newy; 1276 1277 newy = tmp->tm_year; 1278 if (t < sp->ats[0]) 1279 newy -= icycles * YEARSPERREPEAT; 1280 else newy += icycles * YEARSPERREPEAT; 1281 tmp->tm_year = newy; 1282 if (tmp->tm_year != newy) 1283 return NULL; 1284 } 1285 return result; 1286 } 1287 if (sp->timecnt == 0 || t < sp->ats[0]) { 1288 i = 0; 1289 while (sp->ttis[i].tt_isdst) 1290 if (++i >= sp->typecnt) { 1291 i = 0; 1292 break; 1293 } 1294 } else { 1295 register int lo = 1; 1296 register int hi = sp->timecnt; 1297 1298 while (lo < hi) { 1299 register int mid = (lo + hi) >> 1; 1300 1301 if (t < sp->ats[mid]) 1302 hi = mid; 1303 else lo = mid + 1; 1304 } 1305 i = (int) sp->types[lo - 1]; 1306 } 1307 ttisp = &sp->ttis[i]; 1308 /* 1309 ** To get (wrong) behavior that's compatible with System V Release 2.0 1310 ** you'd replace the statement below with 1311 ** t += ttisp->tt_gmtoff; 1312 ** timesub(&t, 0L, sp, tmp); 1313 */ 1314 result = timesub(&t, ttisp->tt_gmtoff, sp, tmp); 1315 tmp->tm_isdst = ttisp->tt_isdst; 1316 tzname[tmp->tm_isdst] = &sp->chars[ttisp->tt_abbrind]; 1317 #ifdef TM_ZONE 1318 tmp->TM_ZONE = &sp->chars[ttisp->tt_abbrind]; 1319 #endif /* defined TM_ZONE */ 1320 return result; 1321 } 1322 1323 struct tm * 1324 localtime(timep) 1325 const time_t * const timep; 1326 { 1327 tzset(); 1328 return localsub(timep, 0L, &tm); 1329 } 1330 1331 /* 1332 ** Re-entrant version of localtime. 1333 */ 1334 1335 struct tm * 1336 localtime_r(timep, tmp) 1337 const time_t * const timep; 1338 struct tm * tmp; 1339 { 1340 return localsub(timep, 0L, tmp); 1341 } 1342 1343 /* 1344 ** gmtsub is to gmtime as localsub is to localtime. 1345 */ 1346 1347 static struct tm * 1348 gmtsub(timep, offset, tmp) 1349 const time_t * const timep; 1350 const long offset; 1351 struct tm * const tmp; 1352 { 1353 register struct tm * result; 1354 1355 if (!gmt_is_set) { 1356 gmt_is_set = TRUE; 1357 #ifdef ALL_STATE 1358 gmtptr = (struct state *) malloc(sizeof *gmtptr); 1359 if (gmtptr != NULL) 1360 #endif /* defined ALL_STATE */ 1361 gmtload(gmtptr); 1362 } 1363 result = timesub(timep, offset, gmtptr, tmp); 1364 #ifdef TM_ZONE 1365 /* 1366 ** Could get fancy here and deliver something such as 1367 ** "UTC+xxxx" or "UTC-xxxx" if offset is non-zero, 1368 ** but this is no time for a treasure hunt. 1369 */ 1370 if (offset != 0) 1371 tmp->TM_ZONE = wildabbr; 1372 else { 1373 #ifdef ALL_STATE 1374 if (gmtptr == NULL) 1375 tmp->TM_ZONE = gmt; 1376 else tmp->TM_ZONE = gmtptr->chars; 1377 #endif /* defined ALL_STATE */ 1378 #ifndef ALL_STATE 1379 tmp->TM_ZONE = gmtptr->chars; 1380 #endif /* State Farm */ 1381 } 1382 #endif /* defined TM_ZONE */ 1383 return result; 1384 } 1385 1386 struct tm * 1387 gmtime(timep) 1388 const time_t * const timep; 1389 { 1390 return gmtsub(timep, 0L, &tm); 1391 } 1392 1393 /* 1394 * Re-entrant version of gmtime. 1395 */ 1396 1397 struct tm * 1398 gmtime_r(timep, tmp) 1399 const time_t * const timep; 1400 struct tm * tmp; 1401 { 1402 return gmtsub(timep, 0L, tmp); 1403 } 1404 1405 #ifdef STD_INSPIRED 1406 1407 struct tm * 1408 offtime(timep, offset) 1409 const time_t * const timep; 1410 const long offset; 1411 { 1412 return gmtsub(timep, offset, &tm); 1413 } 1414 1415 #endif /* defined STD_INSPIRED */ 1416 1417 /* 1418 ** Return the number of leap years through the end of the given year 1419 ** where, to make the math easy, the answer for year zero is defined as zero. 1420 */ 1421 1422 static int 1423 leaps_thru_end_of(y) 1424 register const int y; 1425 { 1426 return (y >= 0) ? (y / 4 - y / 100 + y / 400) : 1427 -(leaps_thru_end_of(-(y + 1)) + 1); 1428 } 1429 1430 static struct tm * 1431 timesub(timep, offset, sp, tmp) 1432 const time_t * const timep; 1433 const long offset; 1434 register const struct state * const sp; 1435 register struct tm * const tmp; 1436 { 1437 register const struct lsinfo * lp; 1438 register time_t tdays; 1439 register int idays; /* unsigned would be so 2003 */ 1440 register long rem; 1441 int y; 1442 register const int * ip; 1443 register long corr; 1444 register int hit; 1445 register int i; 1446 1447 corr = 0; 1448 hit = 0; 1449 #ifdef ALL_STATE 1450 i = (sp == NULL) ? 0 : sp->leapcnt; 1451 #endif /* defined ALL_STATE */ 1452 #ifndef ALL_STATE 1453 i = sp->leapcnt; 1454 #endif /* State Farm */ 1455 while (--i >= 0) { 1456 lp = &sp->lsis[i]; 1457 if (*timep >= lp->ls_trans) { 1458 if (*timep == lp->ls_trans) { 1459 hit = ((i == 0 && lp->ls_corr > 0) || 1460 lp->ls_corr > sp->lsis[i - 1].ls_corr); 1461 if (hit) 1462 while (i > 0 && 1463 sp->lsis[i].ls_trans == 1464 sp->lsis[i - 1].ls_trans + 1 && 1465 sp->lsis[i].ls_corr == 1466 sp->lsis[i - 1].ls_corr + 1) { 1467 ++hit; 1468 --i; 1469 } 1470 } 1471 corr = lp->ls_corr; 1472 break; 1473 } 1474 } 1475 y = EPOCH_YEAR; 1476 tdays = *timep / SECSPERDAY; 1477 rem = *timep - tdays * SECSPERDAY; 1478 while (tdays < 0 || tdays >= year_lengths[isleap(y)]) { 1479 int newy; 1480 register time_t tdelta; 1481 register int idelta; 1482 register int leapdays; 1483 1484 tdelta = tdays / DAYSPERLYEAR; 1485 idelta = tdelta; 1486 if (tdelta - idelta >= 1 || idelta - tdelta >= 1) 1487 return NULL; 1488 if (idelta == 0) 1489 idelta = (tdays < 0) ? -1 : 1; 1490 newy = y; 1491 if (increment_overflow(&newy, idelta)) 1492 return NULL; 1493 leapdays = leaps_thru_end_of(newy - 1) - 1494 leaps_thru_end_of(y - 1); 1495 tdays -= ((time_t) newy - y) * DAYSPERNYEAR; 1496 tdays -= leapdays; 1497 y = newy; 1498 } 1499 { 1500 register long seconds; 1501 1502 seconds = tdays * SECSPERDAY + 0.5; 1503 tdays = seconds / SECSPERDAY; 1504 rem += seconds - tdays * SECSPERDAY; 1505 } 1506 /* 1507 ** Given the range, we can now fearlessly cast... 1508 */ 1509 idays = tdays; 1510 rem += offset - corr; 1511 while (rem < 0) { 1512 rem += SECSPERDAY; 1513 --idays; 1514 } 1515 while (rem >= SECSPERDAY) { 1516 rem -= SECSPERDAY; 1517 ++idays; 1518 } 1519 while (idays < 0) { 1520 if (increment_overflow(&y, -1)) 1521 return NULL; 1522 idays += year_lengths[isleap(y)]; 1523 } 1524 while (idays >= year_lengths[isleap(y)]) { 1525 idays -= year_lengths[isleap(y)]; 1526 if (increment_overflow(&y, 1)) 1527 return NULL; 1528 } 1529 tmp->tm_year = y; 1530 if (increment_overflow(&tmp->tm_year, -TM_YEAR_BASE)) 1531 return NULL; 1532 tmp->tm_yday = idays; 1533 /* 1534 ** The "extra" mods below avoid overflow problems. 1535 */ 1536 tmp->tm_wday = EPOCH_WDAY + 1537 ((y - EPOCH_YEAR) % DAYSPERWEEK) * 1538 (DAYSPERNYEAR % DAYSPERWEEK) + 1539 leaps_thru_end_of(y - 1) - 1540 leaps_thru_end_of(EPOCH_YEAR - 1) + 1541 idays; 1542 tmp->tm_wday %= DAYSPERWEEK; 1543 if (tmp->tm_wday < 0) 1544 tmp->tm_wday += DAYSPERWEEK; 1545 tmp->tm_hour = (int) (rem / SECSPERHOUR); 1546 rem %= SECSPERHOUR; 1547 tmp->tm_min = (int) (rem / SECSPERMIN); 1548 /* 1549 ** A positive leap second requires a special 1550 ** representation. This uses "... ??:59:60" et seq. 1551 */ 1552 tmp->tm_sec = (int) (rem % SECSPERMIN) + hit; 1553 ip = mon_lengths[isleap(y)]; 1554 for (tmp->tm_mon = 0; idays >= ip[tmp->tm_mon]; ++(tmp->tm_mon)) 1555 idays -= ip[tmp->tm_mon]; 1556 tmp->tm_mday = (int) (idays + 1); 1557 tmp->tm_isdst = 0; 1558 #ifdef TM_GMTOFF 1559 tmp->TM_GMTOFF = offset; 1560 #endif /* defined TM_GMTOFF */ 1561 return tmp; 1562 } 1563 1564 char * 1565 ctime(timep) 1566 const time_t * const timep; 1567 { 1568 /* 1569 ** Section 4.12.3.2 of X3.159-1989 requires that 1570 ** The ctime function converts the calendar time pointed to by timer 1571 ** to local time in the form of a string. It is equivalent to 1572 ** asctime(localtime(timer)) 1573 */ 1574 return asctime(localtime(timep)); 1575 } 1576 1577 char * 1578 ctime_r(timep, buf) 1579 const time_t * const timep; 1580 char * buf; 1581 { 1582 struct tm mytm; 1583 1584 return asctime_r(localtime_r(timep, &mytm), buf); 1585 } 1586 1587 /* 1588 ** Adapted from code provided by Robert Elz, who writes: 1589 ** The "best" way to do mktime I think is based on an idea of Bob 1590 ** Kridle's (so its said...) from a long time ago. 1591 ** It does a binary search of the time_t space. Since time_t's are 1592 ** just 32 bits, its a max of 32 iterations (even at 64 bits it 1593 ** would still be very reasonable). 1594 */ 1595 1596 #ifndef WRONG 1597 #define WRONG (-1) 1598 #endif /* !defined WRONG */ 1599 1600 /* 1601 ** Simplified normalize logic courtesy Paul Eggert. 1602 */ 1603 1604 static int 1605 increment_overflow(number, delta) 1606 int * number; 1607 int delta; 1608 { 1609 int number0; 1610 1611 number0 = *number; 1612 *number += delta; 1613 return (*number < number0) != (delta < 0); 1614 } 1615 1616 static int 1617 long_increment_overflow(number, delta) 1618 long * number; 1619 int delta; 1620 { 1621 long number0; 1622 1623 number0 = *number; 1624 *number += delta; 1625 return (*number < number0) != (delta < 0); 1626 } 1627 1628 static int 1629 normalize_overflow(tensptr, unitsptr, base) 1630 int * const tensptr; 1631 int * const unitsptr; 1632 const int base; 1633 { 1634 register int tensdelta; 1635 1636 tensdelta = (*unitsptr >= 0) ? 1637 (*unitsptr / base) : 1638 (-1 - (-1 - *unitsptr) / base); 1639 *unitsptr -= tensdelta * base; 1640 return increment_overflow(tensptr, tensdelta); 1641 } 1642 1643 static int 1644 long_normalize_overflow(tensptr, unitsptr, base) 1645 long * const tensptr; 1646 int * const unitsptr; 1647 const int base; 1648 { 1649 register int tensdelta; 1650 1651 tensdelta = (*unitsptr >= 0) ? 1652 (*unitsptr / base) : 1653 (-1 - (-1 - *unitsptr) / base); 1654 *unitsptr -= tensdelta * base; 1655 return long_increment_overflow(tensptr, tensdelta); 1656 } 1657 1658 static int 1659 tmcomp(atmp, btmp) 1660 register const struct tm * const atmp; 1661 register const struct tm * const btmp; 1662 { 1663 register int result; 1664 1665 if ((result = (atmp->tm_year - btmp->tm_year)) == 0 && 1666 (result = (atmp->tm_mon - btmp->tm_mon)) == 0 && 1667 (result = (atmp->tm_mday - btmp->tm_mday)) == 0 && 1668 (result = (atmp->tm_hour - btmp->tm_hour)) == 0 && 1669 (result = (atmp->tm_min - btmp->tm_min)) == 0) 1670 result = atmp->tm_sec - btmp->tm_sec; 1671 return result; 1672 } 1673 1674 static time_t 1675 time2sub(tmp, funcp, offset, okayp, do_norm_secs) 1676 struct tm * const tmp; 1677 struct tm * (* const funcp)(const time_t*, long, struct tm*); 1678 const long offset; 1679 int * const okayp; 1680 const int do_norm_secs; 1681 { 1682 register const struct state * sp; 1683 register int dir; 1684 register int i, j; 1685 register int saved_seconds; 1686 register long li; 1687 register time_t lo; 1688 register time_t hi; 1689 long y; 1690 time_t newt; 1691 time_t t; 1692 struct tm yourtm, mytm; 1693 1694 *okayp = FALSE; 1695 yourtm = *tmp; 1696 if (do_norm_secs) { 1697 if (normalize_overflow(&yourtm.tm_min, &yourtm.tm_sec, 1698 SECSPERMIN)) 1699 return WRONG; 1700 } 1701 if (normalize_overflow(&yourtm.tm_hour, &yourtm.tm_min, MINSPERHOUR)) 1702 return WRONG; 1703 if (normalize_overflow(&yourtm.tm_mday, &yourtm.tm_hour, HOURSPERDAY)) 1704 return WRONG; 1705 y = yourtm.tm_year; 1706 if (long_normalize_overflow(&y, &yourtm.tm_mon, MONSPERYEAR)) 1707 return WRONG; 1708 /* 1709 ** Turn y into an actual year number for now. 1710 ** It is converted back to an offset from TM_YEAR_BASE later. 1711 */ 1712 if (long_increment_overflow(&y, TM_YEAR_BASE)) 1713 return WRONG; 1714 while (yourtm.tm_mday <= 0) { 1715 if (long_increment_overflow(&y, -1)) 1716 return WRONG; 1717 li = y + (1 < yourtm.tm_mon); 1718 yourtm.tm_mday += year_lengths[isleap(li)]; 1719 } 1720 while (yourtm.tm_mday > DAYSPERLYEAR) { 1721 li = y + (1 < yourtm.tm_mon); 1722 yourtm.tm_mday -= year_lengths[isleap(li)]; 1723 if (long_increment_overflow(&y, 1)) 1724 return WRONG; 1725 } 1726 for ( ; ; ) { 1727 i = mon_lengths[isleap(y)][yourtm.tm_mon]; 1728 if (yourtm.tm_mday <= i) 1729 break; 1730 yourtm.tm_mday -= i; 1731 if (++yourtm.tm_mon >= MONSPERYEAR) { 1732 yourtm.tm_mon = 0; 1733 if (long_increment_overflow(&y, 1)) 1734 return WRONG; 1735 } 1736 } 1737 if (long_increment_overflow(&y, -TM_YEAR_BASE)) 1738 return WRONG; 1739 yourtm.tm_year = y; 1740 if (yourtm.tm_year != y) 1741 return WRONG; 1742 if (yourtm.tm_sec >= 0 && yourtm.tm_sec < SECSPERMIN) 1743 saved_seconds = 0; 1744 else if (y + TM_YEAR_BASE < EPOCH_YEAR) { 1745 /* 1746 ** We can't set tm_sec to 0, because that might push the 1747 ** time below the minimum representable time. 1748 ** Set tm_sec to 59 instead. 1749 ** This assumes that the minimum representable time is 1750 ** not in the same minute that a leap second was deleted from, 1751 ** which is a safer assumption than using 58 would be. 1752 */ 1753 if (increment_overflow(&yourtm.tm_sec, 1 - SECSPERMIN)) 1754 return WRONG; 1755 saved_seconds = yourtm.tm_sec; 1756 yourtm.tm_sec = SECSPERMIN - 1; 1757 } else { 1758 saved_seconds = yourtm.tm_sec; 1759 yourtm.tm_sec = 0; 1760 } 1761 /* 1762 ** Do a binary search (this works whatever time_t's type is). 1763 */ 1764 if (!TYPE_SIGNED(time_t)) { 1765 lo = 0; 1766 hi = lo - 1; 1767 } else if (!TYPE_INTEGRAL(time_t)) { 1768 if (sizeof(time_t) > sizeof(float)) 1769 hi = (time_t) DBL_MAX; 1770 else hi = (time_t) FLT_MAX; 1771 lo = -hi; 1772 } else { 1773 lo = 1; 1774 for (i = 0; i < (int) TYPE_BIT(time_t) - 1; ++i) 1775 lo *= 2; 1776 hi = -(lo + 1); 1777 } 1778 for ( ; ; ) { 1779 t = lo / 2 + hi / 2; 1780 if (t < lo) 1781 t = lo; 1782 else if (t > hi) 1783 t = hi; 1784 if ((*funcp)(&t, offset, &mytm) == NULL) { 1785 /* 1786 ** Assume that t is too extreme to be represented in 1787 ** a struct tm; arrange things so that it is less 1788 ** extreme on the next pass. 1789 */ 1790 dir = (t > 0) ? 1 : -1; 1791 } else dir = tmcomp(&mytm, &yourtm); 1792 if (dir != 0) { 1793 if (t == lo) { 1794 ++t; 1795 if (t <= lo) 1796 return WRONG; 1797 ++lo; 1798 } else if (t == hi) { 1799 --t; 1800 if (t >= hi) 1801 return WRONG; 1802 --hi; 1803 } 1804 if (lo > hi) 1805 return WRONG; 1806 if (dir > 0) 1807 hi = t; 1808 else lo = t; 1809 continue; 1810 } 1811 if (yourtm.tm_isdst < 0 || mytm.tm_isdst == yourtm.tm_isdst) 1812 break; 1813 /* 1814 ** Right time, wrong type. 1815 ** Hunt for right time, right type. 1816 ** It's okay to guess wrong since the guess 1817 ** gets checked. 1818 */ 1819 sp = (const struct state *) 1820 ((funcp == localsub) ? lclptr : gmtptr); 1821 #ifdef ALL_STATE 1822 if (sp == NULL) 1823 return WRONG; 1824 #endif /* defined ALL_STATE */ 1825 for (i = sp->typecnt - 1; i >= 0; --i) { 1826 if (sp->ttis[i].tt_isdst != yourtm.tm_isdst) 1827 continue; 1828 for (j = sp->typecnt - 1; j >= 0; --j) { 1829 if (sp->ttis[j].tt_isdst == yourtm.tm_isdst) 1830 continue; 1831 newt = t + sp->ttis[j].tt_gmtoff - 1832 sp->ttis[i].tt_gmtoff; 1833 if ((*funcp)(&newt, offset, &mytm) == NULL) 1834 continue; 1835 if (tmcomp(&mytm, &yourtm) != 0) 1836 continue; 1837 if (mytm.tm_isdst != yourtm.tm_isdst) 1838 continue; 1839 /* 1840 ** We have a match. 1841 */ 1842 t = newt; 1843 goto label; 1844 } 1845 } 1846 return WRONG; 1847 } 1848 label: 1849 newt = t + saved_seconds; 1850 if ((newt < t) != (saved_seconds < 0)) 1851 return WRONG; 1852 t = newt; 1853 if ((*funcp)(&t, offset, tmp)) 1854 *okayp = TRUE; 1855 return t; 1856 } 1857 1858 static time_t 1859 time2(tmp, funcp, offset, okayp) 1860 struct tm * const tmp; 1861 struct tm * (* const funcp)(const time_t*, long, struct tm*); 1862 const long offset; 1863 int * const okayp; 1864 { 1865 time_t t; 1866 1867 /* 1868 ** First try without normalization of seconds 1869 ** (in case tm_sec contains a value associated with a leap second). 1870 ** If that fails, try with normalization of seconds. 1871 */ 1872 t = time2sub(tmp, funcp, offset, okayp, FALSE); 1873 return *okayp ? t : time2sub(tmp, funcp, offset, okayp, TRUE); 1874 } 1875 1876 static time_t 1877 time1(tmp, funcp, offset) 1878 struct tm * const tmp; 1879 struct tm * (* const funcp)(const time_t *, long, struct tm *); 1880 const long offset; 1881 { 1882 register time_t t; 1883 register const struct state * sp; 1884 register int samei, otheri; 1885 register int sameind, otherind; 1886 register int i; 1887 register int nseen; 1888 int seen[TZ_MAX_TYPES]; 1889 int types[TZ_MAX_TYPES]; 1890 int okay; 1891 1892 if (tmp->tm_isdst > 1) 1893 tmp->tm_isdst = 1; 1894 t = time2(tmp, funcp, offset, &okay); 1895 #ifdef PCTS 1896 /* 1897 ** PCTS code courtesy Grant Sullivan. 1898 */ 1899 if (okay) 1900 return t; 1901 if (tmp->tm_isdst < 0) 1902 tmp->tm_isdst = 0; /* reset to std and try again */ 1903 #endif /* defined PCTS */ 1904 #ifndef PCTS 1905 if (okay || tmp->tm_isdst < 0) 1906 return t; 1907 #endif /* !defined PCTS */ 1908 /* 1909 ** We're supposed to assume that somebody took a time of one type 1910 ** and did some math on it that yielded a "struct tm" that's bad. 1911 ** We try to divine the type they started from and adjust to the 1912 ** type they need. 1913 */ 1914 sp = (const struct state *) ((funcp == localsub) ? lclptr : gmtptr); 1915 #ifdef ALL_STATE 1916 if (sp == NULL) 1917 return WRONG; 1918 #endif /* defined ALL_STATE */ 1919 for (i = 0; i < sp->typecnt; ++i) 1920 seen[i] = FALSE; 1921 nseen = 0; 1922 for (i = sp->timecnt - 1; i >= 0; --i) 1923 if (!seen[sp->types[i]]) { 1924 seen[sp->types[i]] = TRUE; 1925 types[nseen++] = sp->types[i]; 1926 } 1927 for (sameind = 0; sameind < nseen; ++sameind) { 1928 samei = types[sameind]; 1929 if (sp->ttis[samei].tt_isdst != tmp->tm_isdst) 1930 continue; 1931 for (otherind = 0; otherind < nseen; ++otherind) { 1932 otheri = types[otherind]; 1933 if (sp->ttis[otheri].tt_isdst == tmp->tm_isdst) 1934 continue; 1935 tmp->tm_sec += sp->ttis[otheri].tt_gmtoff - 1936 sp->ttis[samei].tt_gmtoff; 1937 tmp->tm_isdst = !tmp->tm_isdst; 1938 t = time2(tmp, funcp, offset, &okay); 1939 if (okay) 1940 return t; 1941 tmp->tm_sec -= sp->ttis[otheri].tt_gmtoff - 1942 sp->ttis[samei].tt_gmtoff; 1943 tmp->tm_isdst = !tmp->tm_isdst; 1944 } 1945 } 1946 return WRONG; 1947 } 1948 1949 time_t 1950 mktime(tmp) 1951 struct tm * const tmp; 1952 { 1953 tzset(); 1954 return time1(tmp, localsub, 0L); 1955 } 1956 1957 #ifdef STD_INSPIRED 1958 1959 time_t 1960 timelocal(tmp) 1961 struct tm * const tmp; 1962 { 1963 tmp->tm_isdst = -1; /* in case it wasn't initialized */ 1964 return mktime(tmp); 1965 } 1966 1967 time_t 1968 timegm(tmp) 1969 struct tm * const tmp; 1970 { 1971 tmp->tm_isdst = 0; 1972 return time1(tmp, gmtsub, 0L); 1973 } 1974 1975 time_t 1976 timeoff(tmp, offset) 1977 struct tm * const tmp; 1978 const long offset; 1979 { 1980 tmp->tm_isdst = 0; 1981 return time1(tmp, gmtsub, offset); 1982 } 1983 1984 #endif /* defined STD_INSPIRED */ 1985 1986 #ifdef CMUCS 1987 1988 /* 1989 ** The following is supplied for compatibility with 1990 ** previous versions of the CMUCS runtime library. 1991 */ 1992 1993 long 1994 gtime(tmp) 1995 struct tm * const tmp; 1996 { 1997 const time_t t = mktime(tmp); 1998 1999 if (t == WRONG) 2000 return -1; 2001 return t; 2002 } 2003 2004 #endif /* defined CMUCS */ 2005 2006 /* 2007 ** XXX--is the below the right way to conditionalize?? 2008 */ 2009 2010 #ifdef STD_INSPIRED 2011 2012 /* 2013 ** IEEE Std 1003.1-1988 (POSIX) legislates that 536457599 2014 ** shall correspond to "Wed Dec 31 23:59:59 UTC 1986", which 2015 ** is not the case if we are accounting for leap seconds. 2016 ** So, we provide the following conversion routines for use 2017 ** when exchanging timestamps with POSIX conforming systems. 2018 */ 2019 2020 static long 2021 leapcorr(timep) 2022 time_t * timep; 2023 { 2024 register struct state * sp; 2025 register struct lsinfo * lp; 2026 register int i; 2027 2028 sp = lclptr; 2029 i = sp->leapcnt; 2030 while (--i >= 0) { 2031 lp = &sp->lsis[i]; 2032 if (*timep >= lp->ls_trans) 2033 return lp->ls_corr; 2034 } 2035 return 0; 2036 } 2037 2038 time_t 2039 time2posix(t) 2040 time_t t; 2041 { 2042 tzset(); 2043 return t - leapcorr(&t); 2044 } 2045 2046 time_t 2047 posix2time(t) 2048 time_t t; 2049 { 2050 time_t x; 2051 time_t y; 2052 2053 tzset(); 2054 /* 2055 ** For a positive leap second hit, the result 2056 ** is not unique. For a negative leap second 2057 ** hit, the corresponding time doesn't exist, 2058 ** so we return an adjacent second. 2059 */ 2060 x = t + leapcorr(&t); 2061 y = x - leapcorr(&x); 2062 if (y < t) { 2063 do { 2064 x++; 2065 y = x - leapcorr(&x); 2066 } while (y < t); 2067 if (t != y) 2068 return x - 1; 2069 } else if (y > t) { 2070 do { 2071 --x; 2072 y = x - leapcorr(&x); 2073 } while (y > t); 2074 if (t != y) 2075 return x + 1; 2076 } 2077 return x; 2078 } 2079 2080 #endif /* defined STD_INSPIRED */ 2081
