localtime.c (51072B)
1 /* 2 ** This file is in the public domain, so clarified as of 3 ** 1996-06-05 by Arthur David Olson. 4 */ 5 6 /* 7 ** Leap second handling from Bradley White. 8 ** POSIX-style TZ environment variable handling from Guy Harris. 9 */ 10 11 /*LINTLIBRARY*/ 12 13 #include <stdbool.h> 14 15 #include "private.h" 16 #include "tzfile.h" 17 #include "fcntl.h" 18 19 #ifndef TZ_ABBR_MAX_LEN 20 #define TZ_ABBR_MAX_LEN 16 21 #endif /* !defined TZ_ABBR_MAX_LEN */ 22 23 #ifndef TZ_ABBR_CHAR_SET 24 #define TZ_ABBR_CHAR_SET \ 25 "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789 :+-._" 26 #endif /* !defined TZ_ABBR_CHAR_SET */ 27 28 #ifndef TZ_ABBR_ERR_CHAR 29 #define TZ_ABBR_ERR_CHAR '_' 30 #endif /* !defined TZ_ABBR_ERR_CHAR */ 31 32 /* 33 ** SunOS 4.1.1 headers lack O_BINARY. 34 */ 35 36 #ifdef O_BINARY 37 #define OPEN_MODE (O_RDONLY | O_BINARY) 38 #endif /* defined O_BINARY */ 39 #ifndef O_BINARY 40 #define OPEN_MODE O_RDONLY 41 #endif /* !defined O_BINARY */ 42 43 #ifndef WILDABBR 44 /* 45 ** Someone might make incorrect use of a time zone abbreviation: 46 ** 1. They might reference tzname[0] before calling tzset (explicitly 47 ** or implicitly). 48 ** 2. They might reference tzname[1] before calling tzset (explicitly 49 ** or implicitly). 50 ** 3. They might reference tzname[1] after setting to a time zone 51 ** in which Daylight Saving Time is never observed. 52 ** 4. They might reference tzname[0] after setting to a time zone 53 ** in which Standard Time is never observed. 54 ** 5. They might reference tm.TM_ZONE after calling offtime. 55 ** What's best to do in the above cases is open to debate; 56 ** for now, we just set things up so that in any of the five cases 57 ** WILDABBR is used. Another possibility: initialize tzname[0] to the 58 ** string "tzname[0] used before set", and similarly for the other cases. 59 ** And another: initialize tzname[0] to "ERA", with an explanation in the 60 ** manual page of what this "time zone abbreviation" means (doing this so 61 ** that tzname[0] has the "normal" length of three characters). 62 */ 63 #define WILDABBR " " 64 #endif /* !defined WILDABBR */ 65 66 static const char wildabbr[] = WILDABBR; 67 68 static const char gmt[] = "GMT"; 69 70 /* 71 ** The DST rules to use if TZ has no rules and we can't load TZDEFRULES. 72 ** We default to US rules as of 1999-08-17. 73 ** POSIX 1003.1 section 8.1.1 says that the default DST rules are 74 ** implementation dependent; for historical reasons, US rules are a 75 ** common default. 76 */ 77 #ifndef TZDEFRULESTRING 78 #define TZDEFRULESTRING ",M4.1.0,M10.5.0" 79 #endif /* !defined TZDEFDST */ 80 81 struct ttinfo { /* time type information */ 82 int_fast32_t tt_gmtoff; /* UT offset in seconds */ 83 int tt_isdst; /* used to set tm_isdst */ 84 int tt_abbrind; /* abbreviation list index */ 85 int tt_ttisstd; /* true if transition is std time */ 86 int tt_ttisgmt; /* true if transition is UT */ 87 }; 88 89 struct lsinfo { /* leap second information */ 90 time_t ls_trans; /* transition time */ 91 int_fast64_t ls_corr; /* correction to apply */ 92 }; 93 94 #define BIGGEST(a, b) (((a) > (b)) ? (a) : (b)) 95 96 #ifdef TZNAME_MAX 97 #define MY_TZNAME_MAX TZNAME_MAX 98 #endif /* defined TZNAME_MAX */ 99 #ifndef TZNAME_MAX 100 #define MY_TZNAME_MAX 255 101 #endif /* !defined TZNAME_MAX */ 102 103 struct state { 104 int leapcnt; 105 int timecnt; 106 int typecnt; 107 int charcnt; 108 int goback; 109 int goahead; 110 time_t ats[TZ_MAX_TIMES]; 111 unsigned char types[TZ_MAX_TIMES]; 112 struct ttinfo ttis[TZ_MAX_TYPES]; 113 char chars[BIGGEST(BIGGEST(TZ_MAX_CHARS + 1, sizeof gmt), 114 (2 * (MY_TZNAME_MAX + 1)))]; 115 struct lsinfo lsis[TZ_MAX_LEAPS]; 116 int defaulttype; /* for early times or if no transitions */ 117 }; 118 119 struct rule { 120 int r_type; /* type of rule--see below */ 121 int r_day; /* day number of rule */ 122 int r_week; /* week number of rule */ 123 int r_mon; /* month number of rule */ 124 int_fast32_t r_time; /* transition time of rule */ 125 }; 126 127 #define JULIAN_DAY 0 /* Jn - Julian day */ 128 #define DAY_OF_YEAR 1 /* n - day of year */ 129 #define MONTH_NTH_DAY_OF_WEEK 2 /* Mm.n.d - month, week, day of week */ 130 131 /* 132 ** Prototypes for static functions. 133 */ 134 135 static int_fast32_t detzcode(const char * codep); 136 static int_fast64_t detzcode64(const char * codep); 137 static int differ_by_repeat(time_t t1, time_t t0); 138 static const char * getzname(const char * strp) ATTRIBUTE_PURE; 139 static const char * getqzname(const char * strp, const int delim) 140 ATTRIBUTE_PURE; 141 static const char * getnum(const char * strp, int * nump, int min, 142 int max); 143 static const char * getsecs(const char * strp, int_fast32_t * secsp); 144 static const char * getoffset(const char * strp, int_fast32_t * offsetp); 145 static const char * getrule(const char * strp, struct rule * rulep); 146 static void gmtload(struct state * sp); 147 static struct tm * gmtsub(const time_t * timep, int_fast32_t offset, 148 struct tm * tmp); 149 static struct tm * localsub(const time_t * timep, int_fast32_t offset, 150 struct tm * tmp); 151 static int increment_overflow(int * number, int delta); 152 static int leaps_thru_end_of(int y) ATTRIBUTE_PURE; 153 static int increment_overflow32(int_fast32_t * number, int delta); 154 static int increment_overflow_time(time_t *t, int_fast32_t delta); 155 static int normalize_overflow32(int_fast32_t * tensptr, 156 int * unitsptr, int base); 157 static int normalize_overflow(int * tensptr, int * unitsptr, 158 int base); 159 static void settzname(void); 160 static time_t time1(struct tm * tmp, 161 struct tm * (*funcp)(const time_t *, 162 int_fast32_t, struct tm *), 163 int_fast32_t offset); 164 static time_t time2(struct tm *tmp, 165 struct tm * (*funcp)(const time_t *, 166 int_fast32_t, struct tm*), 167 int_fast32_t offset, int * okayp); 168 static time_t time2sub(struct tm *tmp, 169 struct tm * (*funcp)(const time_t *, 170 int_fast32_t, struct tm*), 171 int_fast32_t offset, int * okayp, int do_norm_secs); 172 static struct tm * timesub(const time_t * timep, int_fast32_t offset, 173 const struct state * sp, struct tm * tmp); 174 static int tmcomp(const struct tm * atmp, 175 const struct tm * btmp); 176 static int_fast32_t transtime(int year, const struct rule * rulep, 177 int_fast32_t offset) 178 ATTRIBUTE_PURE; 179 static int typesequiv(const struct state * sp, int a, int b); 180 static int tzload(const char * name, struct state * sp, 181 int doextend); 182 static int tzparse(const char * name, struct state * sp, 183 int lastditch); 184 185 #ifdef ALL_STATE 186 static struct state * lclptr; 187 static struct state * gmtptr; 188 #endif /* defined ALL_STATE */ 189 190 #ifndef ALL_STATE 191 static struct state lclmem; 192 static struct state gmtmem; 193 #define lclptr (&lclmem) 194 #define gmtptr (&gmtmem) 195 #endif /* State Farm */ 196 197 #ifndef TZ_STRLEN_MAX 198 #define TZ_STRLEN_MAX 255 199 #endif /* !defined TZ_STRLEN_MAX */ 200 201 static char lcl_TZname[TZ_STRLEN_MAX + 1]; 202 static int lcl_is_set; 203 static int gmt_is_set; 204 205 char * tzname[2] = { 206 (char *) wildabbr, 207 (char *) wildabbr 208 }; 209 210 /* 211 ** Section 4.12.3 of X3.159-1989 requires that 212 ** Except for the strftime function, these functions [asctime, 213 ** ctime, gmtime, localtime] return values in one of two static 214 ** objects: a broken-down time structure and an array of char. 215 ** Thanks to Paul Eggert for noting this. 216 */ 217 218 static struct tm tm; 219 220 #ifdef USG_COMPAT 221 long timezone = 0; 222 int daylight = 0; 223 #endif /* defined USG_COMPAT */ 224 225 #ifdef ALTZONE 226 long altzone = 0; 227 #endif /* defined ALTZONE */ 228 229 static int_fast32_t 230 detzcode(const char *const codep) 231 { 232 register int_fast32_t result; 233 register int i; 234 235 result = (codep[0] & 0x80) ? -1 : 0; 236 for (i = 0; i < 4; ++i) 237 result = (result << 8) | (codep[i] & 0xff); 238 return result; 239 } 240 241 static int_fast64_t 242 detzcode64(const char *const codep) 243 { 244 register int_fast64_t result; 245 register int i; 246 247 result = (codep[0] & 0x80) ? -1 : 0; 248 for (i = 0; i < 8; ++i) 249 result = (result << 8) | (codep[i] & 0xff); 250 return result; 251 } 252 253 static void 254 settzname(void) 255 { 256 register struct state * const sp = lclptr; 257 register int i; 258 259 tzname[0] = tzname[1] = (char *) wildabbr; 260 #ifdef USG_COMPAT 261 daylight = 0; 262 timezone = 0; 263 #endif /* defined USG_COMPAT */ 264 #ifdef ALTZONE 265 altzone = 0; 266 #endif /* defined ALTZONE */ 267 if (sp == NULL) { 268 tzname[0] = tzname[1] = (char *) gmt; 269 return; 270 } 271 /* 272 ** And to get the latest zone names into tzname. . . 273 */ 274 for (i = 0; i < sp->typecnt; ++i) { 275 register const struct ttinfo * const ttisp = &sp->ttis[i]; 276 277 tzname[ttisp->tt_isdst] = &sp->chars[ttisp->tt_abbrind]; 278 } 279 for (i = 0; i < sp->timecnt; ++i) { 280 register const struct ttinfo * const ttisp = 281 &sp->ttis[ 282 sp->types[i]]; 283 284 tzname[ttisp->tt_isdst] = 285 &sp->chars[ttisp->tt_abbrind]; 286 #ifdef USG_COMPAT 287 if (ttisp->tt_isdst) 288 daylight = 1; 289 if (!ttisp->tt_isdst) 290 timezone = -(ttisp->tt_gmtoff); 291 #endif /* defined USG_COMPAT */ 292 #ifdef ALTZONE 293 if (ttisp->tt_isdst) 294 altzone = -(ttisp->tt_gmtoff); 295 #endif /* defined ALTZONE */ 296 } 297 /* 298 ** Finally, scrub the abbreviations. 299 ** First, replace bogus characters. 300 */ 301 for (i = 0; i < sp->charcnt; ++i) 302 if (strchr(TZ_ABBR_CHAR_SET, sp->chars[i]) == NULL) 303 sp->chars[i] = TZ_ABBR_ERR_CHAR; 304 /* 305 ** Second, truncate long abbreviations. 306 */ 307 for (i = 0; i < sp->typecnt; ++i) { 308 register const struct ttinfo * const ttisp = &sp->ttis[i]; 309 register char * cp = &sp->chars[ttisp->tt_abbrind]; 310 311 if (strlen(cp) > TZ_ABBR_MAX_LEN && 312 strcmp(cp, GRANDPARENTED) != 0) 313 *(cp + TZ_ABBR_MAX_LEN) = '\0'; 314 } 315 } 316 317 static int 318 differ_by_repeat(const time_t t1, const time_t t0) 319 { 320 if (TYPE_BIT(time_t) - TYPE_SIGNED(time_t) < SECSPERREPEAT_BITS) 321 return 0; 322 return t1 - t0 == SECSPERREPEAT; 323 } 324 325 static int 326 tzload(register const char *name, register struct state *const sp, 327 register const int doextend) 328 { 329 register const char * p; 330 register int i; 331 register int fid; 332 register int stored; 333 register int nread; 334 typedef union { 335 struct tzhead tzhead; 336 char buf[2 * sizeof(struct tzhead) + 337 2 * sizeof *sp + 338 4 * TZ_MAX_TIMES]; 339 } u_t; 340 #ifdef ALL_STATE 341 register u_t * const up = malloc(sizeof *up); 342 #else /* !defined ALL_STATE */ 343 u_t u; 344 register u_t * const up = &u; 345 #endif /* !defined ALL_STATE */ 346 347 sp->goback = sp->goahead = false; 348 349 if (up == NULL) 350 return -1; 351 352 if (name == NULL && (name = TZDEFAULT) == NULL) 353 goto oops; 354 { 355 register int doaccess; 356 /* 357 ** Section 4.9.1 of the C standard says that 358 ** "FILENAME_MAX expands to an integral constant expression 359 ** that is the size needed for an array of char large enough 360 ** to hold the longest file name string that the implementation 361 ** guarantees can be opened." 362 */ 363 char fullname[FILENAME_MAX + 1]; 364 365 if (name[0] == ':') 366 ++name; 367 doaccess = name[0] == '/'; 368 if (!doaccess) { 369 if ((p = TZDIR) == NULL) 370 goto oops; 371 if ((strlen(p) + strlen(name) + 1) >= sizeof fullname) 372 goto oops; 373 (void) strcpy(fullname, p); 374 (void) strcat(fullname, "/"); 375 (void) strcat(fullname, name); 376 /* 377 ** Set doaccess if '.' (as in "../") shows up in name. 378 */ 379 if (strchr(name, '.') != NULL) 380 doaccess = true; 381 name = fullname; 382 } 383 if (doaccess && access(name, R_OK) != 0) 384 goto oops; 385 if ((fid = open(name, OPEN_MODE)) == -1) 386 goto oops; 387 } 388 nread = read(fid, up->buf, sizeof up->buf); 389 if (close(fid) < 0 || nread <= 0) 390 goto oops; 391 for (stored = 4; stored <= 8; stored *= 2) { 392 int ttisstdcnt; 393 int ttisgmtcnt; 394 int timecnt; 395 396 ttisstdcnt = (int) detzcode(up->tzhead.tzh_ttisstdcnt); 397 ttisgmtcnt = (int) detzcode(up->tzhead.tzh_ttisgmtcnt); 398 sp->leapcnt = (int) detzcode(up->tzhead.tzh_leapcnt); 399 sp->timecnt = (int) detzcode(up->tzhead.tzh_timecnt); 400 sp->typecnt = (int) detzcode(up->tzhead.tzh_typecnt); 401 sp->charcnt = (int) detzcode(up->tzhead.tzh_charcnt); 402 p = up->tzhead.tzh_charcnt + sizeof up->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 goto oops; 410 if (nread - (p - up->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 goto oops; 419 timecnt = 0; 420 for (i = 0; i < sp->timecnt; ++i) { 421 int_fast64_t at 422 = stored == 4 ? detzcode(p) : detzcode64(p); 423 sp->types[i] = ((TYPE_SIGNED(time_t) 424 ? time_t_min <= at 425 : 0 <= at) 426 && at <= time_t_max); 427 if (sp->types[i]) { 428 if (i && !timecnt && at != time_t_min) { 429 /* 430 ** Keep the earlier record, but tweak 431 ** it so that it starts with the 432 ** minimum time_t value. 433 */ 434 sp->types[i - 1] = 1; 435 sp->ats[timecnt++] = time_t_min; 436 } 437 sp->ats[timecnt++] = at; 438 } 439 p += stored; 440 } 441 timecnt = 0; 442 for (i = 0; i < sp->timecnt; ++i) { 443 unsigned char typ = *p++; 444 if (sp->typecnt <= typ) 445 goto oops; 446 if (sp->types[i]) 447 sp->types[timecnt++] = typ; 448 } 449 sp->timecnt = timecnt; 450 for (i = 0; i < sp->typecnt; ++i) { 451 register struct ttinfo * ttisp; 452 453 ttisp = &sp->ttis[i]; 454 ttisp->tt_gmtoff = detzcode(p); 455 p += 4; 456 ttisp->tt_isdst = (unsigned char) *p++; 457 if (ttisp->tt_isdst != 0 && ttisp->tt_isdst != 1) 458 goto oops; 459 ttisp->tt_abbrind = (unsigned char) *p++; 460 if (ttisp->tt_abbrind < 0 || 461 ttisp->tt_abbrind > sp->charcnt) 462 goto oops; 463 } 464 for (i = 0; i < sp->charcnt; ++i) 465 sp->chars[i] = *p++; 466 sp->chars[i] = '\0'; /* ensure '\0' at end */ 467 for (i = 0; i < sp->leapcnt; ++i) { 468 register struct lsinfo * lsisp; 469 470 lsisp = &sp->lsis[i]; 471 lsisp->ls_trans = (stored == 4) ? 472 detzcode(p) : detzcode64(p); 473 p += stored; 474 lsisp->ls_corr = detzcode(p); 475 p += 4; 476 } 477 for (i = 0; i < sp->typecnt; ++i) { 478 register struct ttinfo * ttisp; 479 480 ttisp = &sp->ttis[i]; 481 if (ttisstdcnt == 0) 482 ttisp->tt_ttisstd = false; 483 else { 484 ttisp->tt_ttisstd = *p++; 485 if (ttisp->tt_ttisstd != true && 486 ttisp->tt_ttisstd != false) 487 goto oops; 488 } 489 } 490 for (i = 0; i < sp->typecnt; ++i) { 491 register struct ttinfo * ttisp; 492 493 ttisp = &sp->ttis[i]; 494 if (ttisgmtcnt == 0) 495 ttisp->tt_ttisgmt = false; 496 else { 497 ttisp->tt_ttisgmt = *p++; 498 if (ttisp->tt_ttisgmt != true && 499 ttisp->tt_ttisgmt != false) 500 goto oops; 501 } 502 } 503 /* 504 ** If this is an old file, we're done. 505 */ 506 if (up->tzhead.tzh_version[0] == '\0') 507 break; 508 nread -= p - up->buf; 509 for (i = 0; i < nread; ++i) 510 up->buf[i] = p[i]; 511 /* 512 ** If this is a signed narrow time_t system, we're done. 513 */ 514 if (TYPE_SIGNED(time_t) && stored >= (int) sizeof(time_t)) 515 break; 516 } 517 if (doextend && nread > 2 && 518 up->buf[0] == '\n' && up->buf[nread - 1] == '\n' && 519 sp->typecnt + 2 <= TZ_MAX_TYPES) { 520 struct state ts; 521 register int result; 522 523 up->buf[nread - 1] = '\0'; 524 result = tzparse(&up->buf[1], &ts, false); 525 if (result == 0 && ts.typecnt == 2 && 526 sp->charcnt + ts.charcnt <= TZ_MAX_CHARS) { 527 for (i = 0; i < 2; ++i) 528 ts.ttis[i].tt_abbrind += 529 sp->charcnt; 530 for (i = 0; i < ts.charcnt; ++i) 531 sp->chars[sp->charcnt++] = 532 ts.chars[i]; 533 i = 0; 534 while (i < ts.timecnt && 535 ts.ats[i] <= 536 sp->ats[sp->timecnt - 1]) 537 ++i; 538 while (i < ts.timecnt && 539 sp->timecnt < TZ_MAX_TIMES) { 540 sp->ats[sp->timecnt] = 541 ts.ats[i]; 542 sp->types[sp->timecnt] = 543 sp->typecnt + 544 ts.types[i]; 545 ++sp->timecnt; 546 ++i; 547 } 548 sp->ttis[sp->typecnt++] = ts.ttis[0]; 549 sp->ttis[sp->typecnt++] = ts.ttis[1]; 550 } 551 } 552 if (sp->timecnt > 1) { 553 for (i = 1; i < sp->timecnt; ++i) 554 if (typesequiv(sp, sp->types[i], sp->types[0]) && 555 differ_by_repeat(sp->ats[i], sp->ats[0])) { 556 sp->goback = true; 557 break; 558 } 559 for (i = sp->timecnt - 2; i >= 0; --i) 560 if (typesequiv(sp, sp->types[sp->timecnt - 1], 561 sp->types[i]) && 562 differ_by_repeat(sp->ats[sp->timecnt - 1], 563 sp->ats[i])) { 564 sp->goahead = true; 565 break; 566 } 567 } 568 /* 569 ** If type 0 is unused in transitions, 570 ** it's the type to use for early times. 571 */ 572 for (i = 0; i < sp->typecnt; ++i) 573 if (sp->types[i] == 0) 574 break; 575 i = (i >= sp->typecnt) ? 0 : -1; 576 /* 577 ** Absent the above, 578 ** if there are transition times 579 ** and the first transition is to a daylight time 580 ** find the standard type less than and closest to 581 ** the type of the first transition. 582 */ 583 if (i < 0 && sp->timecnt > 0 && sp->ttis[sp->types[0]].tt_isdst) { 584 i = sp->types[0]; 585 while (--i >= 0) 586 if (!sp->ttis[i].tt_isdst) 587 break; 588 } 589 /* 590 ** If no result yet, find the first standard type. 591 ** If there is none, punt to type zero. 592 */ 593 if (i < 0) { 594 i = 0; 595 while (sp->ttis[i].tt_isdst) 596 if (++i >= sp->typecnt) { 597 i = 0; 598 break; 599 } 600 } 601 sp->defaulttype = i; 602 #ifdef ALL_STATE 603 free(up); 604 #endif /* defined ALL_STATE */ 605 return 0; 606 oops: 607 #ifdef ALL_STATE 608 free(up); 609 #endif /* defined ALL_STATE */ 610 return -1; 611 } 612 613 static int 614 typesequiv(const struct state *const sp, const int a, const int b) 615 { 616 register int result; 617 618 if (sp == NULL || 619 a < 0 || a >= sp->typecnt || 620 b < 0 || b >= sp->typecnt) 621 result = false; 622 else { 623 register const struct ttinfo * ap = &sp->ttis[a]; 624 register const struct ttinfo * bp = &sp->ttis[b]; 625 result = ap->tt_gmtoff == bp->tt_gmtoff && 626 ap->tt_isdst == bp->tt_isdst && 627 ap->tt_ttisstd == bp->tt_ttisstd && 628 ap->tt_ttisgmt == bp->tt_ttisgmt && 629 strcmp(&sp->chars[ap->tt_abbrind], 630 &sp->chars[bp->tt_abbrind]) == 0; 631 } 632 return result; 633 } 634 635 static const int mon_lengths[2][MONSPERYEAR] = { 636 { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }, 637 { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 } 638 }; 639 640 static const int year_lengths[2] = { 641 DAYSPERNYEAR, DAYSPERLYEAR 642 }; 643 644 /* 645 ** Given a pointer into a time zone string, scan until a character that is not 646 ** a valid character in a zone name is found. Return a pointer to that 647 ** character. 648 */ 649 650 static const char * 651 getzname(register const char *strp) 652 { 653 register char c; 654 655 while ((c = *strp) != '\0' && !is_digit(c) && c != ',' && c != '-' && 656 c != '+') 657 ++strp; 658 return strp; 659 } 660 661 /* 662 ** Given a pointer into an extended time zone string, scan until the ending 663 ** delimiter of the zone name is located. Return a pointer to the delimiter. 664 ** 665 ** As with getzname above, the legal character set is actually quite 666 ** restricted, with other characters producing undefined results. 667 ** We don't do any checking here; checking is done later in common-case code. 668 */ 669 670 static const char * 671 getqzname(register const char *strp, const int delim) 672 { 673 register int c; 674 675 while ((c = *strp) != '\0' && c != delim) 676 ++strp; 677 return strp; 678 } 679 680 /* 681 ** Given a pointer into a time zone string, extract a number from that string. 682 ** Check that the number is within a specified range; if it is not, return 683 ** NULL. 684 ** Otherwise, return a pointer to the first character not part of the number. 685 */ 686 687 static const char * 688 getnum(register const char *strp, int *const nump, const int min, const int max) 689 { 690 register char c; 691 register int num; 692 693 if (strp == NULL || !is_digit(c = *strp)) 694 return NULL; 695 num = 0; 696 do { 697 num = num * 10 + (c - '0'); 698 if (num > max) 699 return NULL; /* illegal value */ 700 c = *++strp; 701 } while (is_digit(c)); 702 if (num < min) 703 return NULL; /* illegal value */ 704 *nump = num; 705 return strp; 706 } 707 708 /* 709 ** Given a pointer into a time zone string, extract a number of seconds, 710 ** in hh[:mm[:ss]] form, from the string. 711 ** If any error occurs, return NULL. 712 ** Otherwise, return a pointer to the first character not part of the number 713 ** of seconds. 714 */ 715 716 static const char * 717 getsecs(register const char *strp, int_fast32_t *const secsp) 718 { 719 int num; 720 721 /* 722 ** `HOURSPERDAY * DAYSPERWEEK - 1' allows quasi-Posix rules like 723 ** "M10.4.6/26", which does not conform to Posix, 724 ** but which specifies the equivalent of 725 ** ``02:00 on the first Sunday on or after 23 Oct''. 726 */ 727 strp = getnum(strp, &num, 0, HOURSPERDAY * DAYSPERWEEK - 1); 728 if (strp == NULL) 729 return NULL; 730 *secsp = num * (int_fast32_t) SECSPERHOUR; 731 if (*strp == ':') { 732 ++strp; 733 strp = getnum(strp, &num, 0, MINSPERHOUR - 1); 734 if (strp == NULL) 735 return NULL; 736 *secsp += num * SECSPERMIN; 737 if (*strp == ':') { 738 ++strp; 739 /* `SECSPERMIN' allows for leap seconds. */ 740 strp = getnum(strp, &num, 0, SECSPERMIN); 741 if (strp == NULL) 742 return NULL; 743 *secsp += num; 744 } 745 } 746 return strp; 747 } 748 749 /* 750 ** Given a pointer into a time zone string, extract an offset, in 751 ** [+-]hh[:mm[:ss]] form, from the string. 752 ** If any error occurs, return NULL. 753 ** Otherwise, return a pointer to the first character not part of the time. 754 */ 755 756 static const char * 757 getoffset(register const char *strp, int_fast32_t *const offsetp) 758 { 759 register int neg = 0; 760 761 if (*strp == '-') { 762 neg = 1; 763 ++strp; 764 } else if (*strp == '+') 765 ++strp; 766 strp = getsecs(strp, offsetp); 767 if (strp == NULL) 768 return NULL; /* illegal time */ 769 if (neg) 770 *offsetp = -*offsetp; 771 return strp; 772 } 773 774 /* 775 ** Given a pointer into a time zone string, extract a rule in the form 776 ** date[/time]. See POSIX section 8 for the format of "date" and "time". 777 ** If a valid rule is not found, return NULL. 778 ** Otherwise, return a pointer to the first character not part of the rule. 779 */ 780 781 static const char * 782 getrule(const char *strp, register struct rule *const rulep) 783 { 784 if (*strp == 'J') { 785 /* 786 ** Julian day. 787 */ 788 rulep->r_type = JULIAN_DAY; 789 ++strp; 790 strp = getnum(strp, &rulep->r_day, 1, DAYSPERNYEAR); 791 } else if (*strp == 'M') { 792 /* 793 ** Month, week, day. 794 */ 795 rulep->r_type = MONTH_NTH_DAY_OF_WEEK; 796 ++strp; 797 strp = getnum(strp, &rulep->r_mon, 1, MONSPERYEAR); 798 if (strp == NULL) 799 return NULL; 800 if (*strp++ != '.') 801 return NULL; 802 strp = getnum(strp, &rulep->r_week, 1, 5); 803 if (strp == NULL) 804 return NULL; 805 if (*strp++ != '.') 806 return NULL; 807 strp = getnum(strp, &rulep->r_day, 0, DAYSPERWEEK - 1); 808 } else if (is_digit(*strp)) { 809 /* 810 ** Day of year. 811 */ 812 rulep->r_type = DAY_OF_YEAR; 813 strp = getnum(strp, &rulep->r_day, 0, DAYSPERLYEAR - 1); 814 } else return NULL; /* invalid format */ 815 if (strp == NULL) 816 return NULL; 817 if (*strp == '/') { 818 /* 819 ** Time specified. 820 */ 821 ++strp; 822 strp = getoffset(strp, &rulep->r_time); 823 } else rulep->r_time = 2 * SECSPERHOUR; /* default = 2:00:00 */ 824 return strp; 825 } 826 827 /* 828 ** Given a year, a rule, and the offset from UT at the time that rule takes 829 ** effect, calculate the year-relative time that rule takes effect. 830 */ 831 832 static int_fast32_t 833 transtime(const int year, register const struct rule *const rulep, 834 const int_fast32_t offset) 835 { 836 register int leapyear; 837 register int_fast32_t value; 838 register int i; 839 int d, m1, yy0, yy1, yy2, dow; 840 841 INITIALIZE(value); 842 leapyear = isleap(year); 843 switch (rulep->r_type) { 844 845 case JULIAN_DAY: 846 /* 847 ** Jn - Julian day, 1 == January 1, 60 == March 1 even in leap 848 ** years. 849 ** In non-leap years, or if the day number is 59 or less, just 850 ** add SECSPERDAY times the day number-1 to the time of 851 ** January 1, midnight, to get the day. 852 */ 853 value = (rulep->r_day - 1) * SECSPERDAY; 854 if (leapyear && rulep->r_day >= 60) 855 value += SECSPERDAY; 856 break; 857 858 case DAY_OF_YEAR: 859 /* 860 ** n - day of year. 861 ** Just add SECSPERDAY times the day number to the time of 862 ** January 1, midnight, to get the day. 863 */ 864 value = rulep->r_day * SECSPERDAY; 865 break; 866 867 case MONTH_NTH_DAY_OF_WEEK: 868 /* 869 ** Mm.n.d - nth "dth day" of month m. 870 */ 871 872 /* 873 ** Use Zeller's Congruence to get day-of-week of first day of 874 ** month. 875 */ 876 m1 = (rulep->r_mon + 9) % 12 + 1; 877 yy0 = (rulep->r_mon <= 2) ? (year - 1) : year; 878 yy1 = yy0 / 100; 879 yy2 = yy0 % 100; 880 dow = ((26 * m1 - 2) / 10 + 881 1 + yy2 + yy2 / 4 + yy1 / 4 - 2 * yy1) % 7; 882 if (dow < 0) 883 dow += DAYSPERWEEK; 884 885 /* 886 ** "dow" is the day-of-week of the first day of the month. Get 887 ** the day-of-month (zero-origin) of the first "dow" day of the 888 ** month. 889 */ 890 d = rulep->r_day - dow; 891 if (d < 0) 892 d += DAYSPERWEEK; 893 for (i = 1; i < rulep->r_week; ++i) { 894 if (d + DAYSPERWEEK >= 895 mon_lengths[leapyear][rulep->r_mon - 1]) 896 break; 897 d += DAYSPERWEEK; 898 } 899 900 /* 901 ** "d" is the day-of-month (zero-origin) of the day we want. 902 */ 903 value = d * SECSPERDAY; 904 for (i = 0; i < rulep->r_mon - 1; ++i) 905 value += mon_lengths[leapyear][i] * SECSPERDAY; 906 break; 907 } 908 909 /* 910 ** "value" is the year-relative time of 00:00:00 UT on the day in 911 ** question. To get the year-relative time of the specified local 912 ** time on that day, add the transition time and the current offset 913 ** from UT. 914 */ 915 return value + rulep->r_time + offset; 916 } 917 918 /* 919 ** Given a POSIX section 8-style TZ string, fill in the rule tables as 920 ** appropriate. 921 */ 922 923 static int 924 tzparse(const char *name, register struct state *const sp, 925 const int lastditch) 926 { 927 const char * stdname; 928 const char * dstname; 929 size_t stdlen; 930 size_t dstlen; 931 int_fast32_t stdoffset; 932 int_fast32_t dstoffset; 933 register char * cp; 934 register int load_result; 935 static struct ttinfo zttinfo; 936 937 INITIALIZE(dstname); 938 stdname = name; 939 if (lastditch) { 940 stdlen = strlen(name); /* length of standard zone name */ 941 name += stdlen; 942 if (stdlen >= sizeof sp->chars) 943 stdlen = (sizeof sp->chars) - 1; 944 stdoffset = 0; 945 } else { 946 if (*name == '<') { 947 name++; 948 stdname = name; 949 name = getqzname(name, '>'); 950 if (*name != '>') 951 return (-1); 952 stdlen = name - stdname; 953 name++; 954 } else { 955 name = getzname(name); 956 stdlen = name - stdname; 957 } 958 if (*name == '\0') 959 return -1; 960 name = getoffset(name, &stdoffset); 961 if (name == NULL) 962 return -1; 963 } 964 load_result = tzload(TZDEFRULES, sp, false); 965 if (load_result != 0) 966 sp->leapcnt = 0; /* so, we're off a little */ 967 if (*name != '\0') { 968 if (*name == '<') { 969 dstname = ++name; 970 name = getqzname(name, '>'); 971 if (*name != '>') 972 return -1; 973 dstlen = name - dstname; 974 name++; 975 } else { 976 dstname = name; 977 name = getzname(name); 978 dstlen = name - dstname; /* length of DST zone name */ 979 } 980 if (*name != '\0' && *name != ',' && *name != ';') { 981 name = getoffset(name, &dstoffset); 982 if (name == NULL) 983 return -1; 984 } else dstoffset = stdoffset - SECSPERHOUR; 985 if (*name == '\0' && load_result != 0) 986 name = TZDEFRULESTRING; 987 if (*name == ',' || *name == ';') { 988 struct rule start; 989 struct rule end; 990 register int year; 991 register int yearlim; 992 register int timecnt; 993 time_t janfirst; 994 995 ++name; 996 if ((name = getrule(name, &start)) == NULL) 997 return -1; 998 if (*name++ != ',') 999 return -1; 1000 if ((name = getrule(name, &end)) == NULL) 1001 return -1; 1002 if (*name != '\0') 1003 return -1; 1004 sp->typecnt = 2; /* standard time and DST */ 1005 /* 1006 ** Two transitions per year, from EPOCH_YEAR forward. 1007 */ 1008 sp->ttis[0] = sp->ttis[1] = zttinfo; 1009 sp->ttis[0].tt_gmtoff = -dstoffset; 1010 sp->ttis[0].tt_isdst = 1; 1011 sp->ttis[0].tt_abbrind = stdlen + 1; 1012 sp->ttis[1].tt_gmtoff = -stdoffset; 1013 sp->ttis[1].tt_isdst = 0; 1014 sp->ttis[1].tt_abbrind = 0; 1015 sp->defaulttype = 0; 1016 timecnt = 0; 1017 janfirst = 0; 1018 yearlim = EPOCH_YEAR + YEARSPERREPEAT; 1019 for (year = EPOCH_YEAR; year < yearlim; year++) { 1020 int_fast32_t 1021 starttime = transtime(year, &start, stdoffset), 1022 endtime = transtime(year, &end, dstoffset); 1023 int_fast32_t 1024 yearsecs = (year_lengths[isleap(year)] 1025 * SECSPERDAY); 1026 int reversed = endtime < starttime; 1027 if (reversed) { 1028 int_fast32_t swap = starttime; 1029 starttime = endtime; 1030 endtime = swap; 1031 } 1032 if (reversed 1033 || (starttime < endtime 1034 && (endtime - starttime 1035 < (yearsecs 1036 + (stdoffset - dstoffset))))) { 1037 if (TZ_MAX_TIMES - 2 < timecnt) 1038 break; 1039 yearlim = year + YEARSPERREPEAT + 1; 1040 sp->ats[timecnt] = janfirst; 1041 if (increment_overflow_time 1042 (&sp->ats[timecnt], starttime)) 1043 break; 1044 sp->types[timecnt++] = reversed; 1045 sp->ats[timecnt] = janfirst; 1046 if (increment_overflow_time 1047 (&sp->ats[timecnt], endtime)) 1048 break; 1049 sp->types[timecnt++] = !reversed; 1050 } 1051 if (increment_overflow_time(&janfirst, yearsecs)) 1052 break; 1053 } 1054 sp->timecnt = timecnt; 1055 if (!timecnt) 1056 sp->typecnt = 1; /* Perpetual DST. */ 1057 } else { 1058 register int_fast32_t theirstdoffset; 1059 register int_fast32_t theirdstoffset; 1060 register int_fast32_t theiroffset; 1061 register int isdst; 1062 register int i; 1063 register int j; 1064 1065 if (*name != '\0') 1066 return -1; 1067 /* 1068 ** Initial values of theirstdoffset and theirdstoffset. 1069 */ 1070 theirstdoffset = 0; 1071 for (i = 0; i < sp->timecnt; ++i) { 1072 j = sp->types[i]; 1073 if (!sp->ttis[j].tt_isdst) { 1074 theirstdoffset = 1075 -sp->ttis[j].tt_gmtoff; 1076 break; 1077 } 1078 } 1079 theirdstoffset = 0; 1080 for (i = 0; i < sp->timecnt; ++i) { 1081 j = sp->types[i]; 1082 if (sp->ttis[j].tt_isdst) { 1083 theirdstoffset = 1084 -sp->ttis[j].tt_gmtoff; 1085 break; 1086 } 1087 } 1088 /* 1089 ** Initially we're assumed to be in standard time. 1090 */ 1091 isdst = false; 1092 theiroffset = theirstdoffset; 1093 /* 1094 ** Now juggle transition times and types 1095 ** tracking offsets as you do. 1096 */ 1097 for (i = 0; i < sp->timecnt; ++i) { 1098 j = sp->types[i]; 1099 sp->types[i] = sp->ttis[j].tt_isdst; 1100 if (sp->ttis[j].tt_ttisgmt) { 1101 /* No adjustment to transition time */ 1102 } else { 1103 /* 1104 ** If summer time is in effect, and the 1105 ** transition time was not specified as 1106 ** standard time, add the summer time 1107 ** offset to the transition time; 1108 ** otherwise, add the standard time 1109 ** offset to the transition time. 1110 */ 1111 /* 1112 ** Transitions from DST to DDST 1113 ** will effectively disappear since 1114 ** POSIX provides for only one DST 1115 ** offset. 1116 */ 1117 if (isdst && !sp->ttis[j].tt_ttisstd) { 1118 sp->ats[i] += dstoffset - 1119 theirdstoffset; 1120 } else { 1121 sp->ats[i] += stdoffset - 1122 theirstdoffset; 1123 } 1124 } 1125 theiroffset = -sp->ttis[j].tt_gmtoff; 1126 if (sp->ttis[j].tt_isdst) 1127 theirdstoffset = theiroffset; 1128 else theirstdoffset = theiroffset; 1129 } 1130 /* 1131 ** Finally, fill in ttis. 1132 */ 1133 sp->ttis[0] = sp->ttis[1] = zttinfo; 1134 sp->ttis[0].tt_gmtoff = -stdoffset; 1135 sp->ttis[0].tt_isdst = false; 1136 sp->ttis[0].tt_abbrind = 0; 1137 sp->ttis[1].tt_gmtoff = -dstoffset; 1138 sp->ttis[1].tt_isdst = true; 1139 sp->ttis[1].tt_abbrind = stdlen + 1; 1140 sp->typecnt = 2; 1141 sp->defaulttype = 0; 1142 } 1143 } else { 1144 dstlen = 0; 1145 sp->typecnt = 1; /* only standard time */ 1146 sp->timecnt = 0; 1147 sp->ttis[0] = zttinfo; 1148 sp->ttis[0].tt_gmtoff = -stdoffset; 1149 sp->ttis[0].tt_isdst = 0; 1150 sp->ttis[0].tt_abbrind = 0; 1151 sp->defaulttype = 0; 1152 } 1153 sp->charcnt = stdlen + 1; 1154 if (dstlen != 0) 1155 sp->charcnt += dstlen + 1; 1156 if ((size_t) sp->charcnt > sizeof sp->chars) 1157 return -1; 1158 cp = sp->chars; 1159 (void) strncpy(cp, stdname, stdlen); 1160 cp += stdlen; 1161 *cp++ = '\0'; 1162 if (dstlen != 0) { 1163 (void) strncpy(cp, dstname, dstlen); 1164 *(cp + dstlen) = '\0'; 1165 } 1166 return 0; 1167 } 1168 1169 static void 1170 gmtload(struct state *const sp) 1171 { 1172 if (tzload(gmt, sp, true) != 0) 1173 (void) tzparse(gmt, sp, true); 1174 } 1175 1176 #ifndef STD_INSPIRED 1177 /* 1178 ** A non-static declaration of tzsetwall in a system header file 1179 ** may cause a warning about this upcoming static declaration... 1180 */ 1181 static 1182 #endif /* !defined STD_INSPIRED */ 1183 void 1184 tzsetwall(void) 1185 { 1186 if (lcl_is_set < 0) 1187 return; 1188 lcl_is_set = -1; 1189 1190 #ifdef ALL_STATE 1191 if (lclptr == NULL) { 1192 lclptr = malloc(sizeof *lclptr); 1193 if (lclptr == NULL) { 1194 settzname(); /* all we can do */ 1195 return; 1196 } 1197 } 1198 #endif /* defined ALL_STATE */ 1199 if (tzload(NULL, lclptr, true) != 0) 1200 gmtload(lclptr); 1201 settzname(); 1202 } 1203 1204 void 1205 tzset(void) 1206 { 1207 register const char * name; 1208 1209 name = getenv("TZ"); 1210 if (name == NULL) { 1211 tzsetwall(); 1212 return; 1213 } 1214 1215 if (lcl_is_set > 0 && strcmp(lcl_TZname, name) == 0) 1216 return; 1217 lcl_is_set = strlen(name) < sizeof lcl_TZname; 1218 if (lcl_is_set) 1219 (void) strcpy(lcl_TZname, name); 1220 1221 #ifdef ALL_STATE 1222 if (lclptr == NULL) { 1223 lclptr = malloc(sizeof *lclptr); 1224 if (lclptr == NULL) { 1225 settzname(); /* all we can do */ 1226 return; 1227 } 1228 } 1229 #endif /* defined ALL_STATE */ 1230 if (*name == '\0') { 1231 /* 1232 ** User wants it fast rather than right. 1233 */ 1234 lclptr->leapcnt = 0; /* so, we're off a little */ 1235 lclptr->timecnt = 0; 1236 lclptr->typecnt = 0; 1237 lclptr->ttis[0].tt_isdst = 0; 1238 lclptr->ttis[0].tt_gmtoff = 0; 1239 lclptr->ttis[0].tt_abbrind = 0; 1240 (void) strcpy(lclptr->chars, gmt); 1241 } else if (tzload(name, lclptr, true) != 0) 1242 if (name[0] == ':' || tzparse(name, lclptr, false) != 0) 1243 (void) gmtload(lclptr); 1244 settzname(); 1245 } 1246 1247 /* 1248 ** The easy way to behave "as if no library function calls" localtime 1249 ** is to not call it--so we drop its guts into "localsub", which can be 1250 ** freely called. (And no, the PANS doesn't require the above behavior-- 1251 ** but it *is* desirable.) 1252 ** 1253 ** The unused offset argument is for the benefit of mktime variants. 1254 */ 1255 1256 /*ARGSUSED*/ 1257 static struct tm * 1258 localsub(const time_t *const timep, const int_fast32_t offset, 1259 struct tm *const tmp) 1260 { 1261 register struct state * sp; 1262 register const struct ttinfo * ttisp; 1263 register int i; 1264 register struct tm * result; 1265 const time_t t = *timep; 1266 1267 sp = lclptr; 1268 if (sp == NULL) 1269 return gmtsub(timep, offset, tmp); 1270 if ((sp->goback && t < sp->ats[0]) || 1271 (sp->goahead && t > sp->ats[sp->timecnt - 1])) { 1272 time_t newt = t; 1273 register time_t seconds; 1274 register time_t years; 1275 1276 if (t < sp->ats[0]) 1277 seconds = sp->ats[0] - t; 1278 else seconds = t - sp->ats[sp->timecnt - 1]; 1279 --seconds; 1280 years = (seconds / SECSPERREPEAT + 1) * YEARSPERREPEAT; 1281 seconds = years * AVGSECSPERYEAR; 1282 if (t < sp->ats[0]) 1283 newt += seconds; 1284 else newt -= seconds; 1285 if (newt < sp->ats[0] || 1286 newt > sp->ats[sp->timecnt - 1]) 1287 return NULL; /* "cannot happen" */ 1288 result = localsub(&newt, offset, tmp); 1289 if (result == tmp) { 1290 register time_t newy; 1291 1292 newy = tmp->tm_year; 1293 if (t < sp->ats[0]) 1294 newy -= years; 1295 else newy += years; 1296 tmp->tm_year = newy; 1297 if (tmp->tm_year != newy) 1298 return NULL; 1299 } 1300 return result; 1301 } 1302 if (sp->timecnt == 0 || t < sp->ats[0]) { 1303 i = sp->defaulttype; 1304 } else { 1305 register int lo = 1; 1306 register int hi = sp->timecnt; 1307 1308 while (lo < hi) { 1309 register int mid = (lo + hi) >> 1; 1310 1311 if (t < sp->ats[mid]) 1312 hi = mid; 1313 else lo = mid + 1; 1314 } 1315 i = (int) sp->types[lo - 1]; 1316 } 1317 ttisp = &sp->ttis[i]; 1318 /* 1319 ** To get (wrong) behavior that's compatible with System V Release 2.0 1320 ** you'd replace the statement below with 1321 ** t += ttisp->tt_gmtoff; 1322 ** timesub(&t, 0L, sp, tmp); 1323 */ 1324 result = timesub(&t, ttisp->tt_gmtoff, sp, tmp); 1325 tmp->tm_isdst = ttisp->tt_isdst; 1326 tzname[tmp->tm_isdst] = &sp->chars[ttisp->tt_abbrind]; 1327 #ifdef TM_ZONE 1328 tmp->TM_ZONE = &sp->chars[ttisp->tt_abbrind]; 1329 #endif /* defined TM_ZONE */ 1330 return result; 1331 } 1332 1333 struct tm * 1334 localtime(const time_t *const timep) 1335 { 1336 tzset(); 1337 return localsub(timep, 0L, &tm); 1338 } 1339 1340 /* 1341 ** Re-entrant version of localtime. 1342 */ 1343 1344 struct tm * 1345 localtime_r(const time_t *const timep, struct tm *tmp) 1346 { 1347 return localsub(timep, 0L, tmp); 1348 } 1349 1350 /* 1351 ** gmtsub is to gmtime as localsub is to localtime. 1352 */ 1353 1354 static struct tm * 1355 gmtsub(const time_t *const timep, const int_fast32_t offset, 1356 struct tm *const tmp) 1357 { 1358 register struct tm * result; 1359 1360 if (!gmt_is_set) { 1361 gmt_is_set = true; 1362 #ifdef ALL_STATE 1363 gmtptr = malloc(sizeof *gmtptr); 1364 #endif /* defined ALL_STATE */ 1365 if (gmtptr != NULL) 1366 gmtload(gmtptr); 1367 } 1368 result = timesub(timep, offset, gmtptr, tmp); 1369 #ifdef TM_ZONE 1370 /* 1371 ** Could get fancy here and deliver something such as 1372 ** "UT+xxxx" or "UT-xxxx" if offset is non-zero, 1373 ** but this is no time for a treasure hunt. 1374 */ 1375 tmp->TM_ZONE = offset ? wildabbr : gmtptr ? gmtptr->chars : gmt; 1376 #endif /* defined TM_ZONE */ 1377 return result; 1378 } 1379 1380 struct tm * 1381 gmtime(const time_t *const timep) 1382 { 1383 return gmtsub(timep, 0L, &tm); 1384 } 1385 1386 /* 1387 * Re-entrant version of gmtime. 1388 */ 1389 1390 struct tm * 1391 gmtime_r(const time_t *const timep, struct tm *tmp) 1392 { 1393 return gmtsub(timep, 0L, tmp); 1394 } 1395 1396 #ifdef STD_INSPIRED 1397 1398 struct tm * 1399 offtime(const time_t *const timep, const long offset) 1400 { 1401 return gmtsub(timep, offset, &tm); 1402 } 1403 1404 #endif /* defined STD_INSPIRED */ 1405 1406 /* 1407 ** Return the number of leap years through the end of the given year 1408 ** where, to make the math easy, the answer for year zero is defined as zero. 1409 */ 1410 1411 static int 1412 leaps_thru_end_of(register const int y) 1413 { 1414 return (y >= 0) ? (y / 4 - y / 100 + y / 400) : 1415 -(leaps_thru_end_of(-(y + 1)) + 1); 1416 } 1417 1418 static struct tm * 1419 timesub(const time_t *const timep, const int_fast32_t offset, 1420 register const struct state *const sp, 1421 register struct tm *const tmp) 1422 { 1423 register const struct lsinfo * lp; 1424 register time_t tdays; 1425 register int idays; /* unsigned would be so 2003 */ 1426 register int_fast64_t rem; 1427 int y; 1428 register const int * ip; 1429 register int_fast64_t corr; 1430 register int hit; 1431 register int i; 1432 1433 corr = 0; 1434 hit = 0; 1435 i = (sp == NULL) ? 0 : sp->leapcnt; 1436 while (--i >= 0) { 1437 lp = &sp->lsis[i]; 1438 if (*timep >= lp->ls_trans) { 1439 if (*timep == lp->ls_trans) { 1440 hit = ((i == 0 && lp->ls_corr > 0) || 1441 lp->ls_corr > sp->lsis[i - 1].ls_corr); 1442 if (hit) 1443 while (i > 0 && 1444 sp->lsis[i].ls_trans == 1445 sp->lsis[i - 1].ls_trans + 1 && 1446 sp->lsis[i].ls_corr == 1447 sp->lsis[i - 1].ls_corr + 1) { 1448 ++hit; 1449 --i; 1450 } 1451 } 1452 corr = lp->ls_corr; 1453 break; 1454 } 1455 } 1456 y = EPOCH_YEAR; 1457 tdays = *timep / SECSPERDAY; 1458 rem = *timep - tdays * SECSPERDAY; 1459 while (tdays < 0 || tdays >= year_lengths[isleap(y)]) { 1460 int newy; 1461 register time_t tdelta; 1462 register int idelta; 1463 register int leapdays; 1464 1465 tdelta = tdays / DAYSPERLYEAR; 1466 if (! ((! TYPE_SIGNED(time_t) || INT_MIN <= tdelta) 1467 && tdelta <= INT_MAX)) 1468 return NULL; 1469 idelta = tdelta; 1470 if (idelta == 0) 1471 idelta = (tdays < 0) ? -1 : 1; 1472 newy = y; 1473 if (increment_overflow(&newy, idelta)) 1474 return NULL; 1475 leapdays = leaps_thru_end_of(newy - 1) - 1476 leaps_thru_end_of(y - 1); 1477 tdays -= ((time_t) newy - y) * DAYSPERNYEAR; 1478 tdays -= leapdays; 1479 y = newy; 1480 } 1481 { 1482 register int_fast32_t seconds; 1483 1484 seconds = tdays * SECSPERDAY; 1485 tdays = seconds / SECSPERDAY; 1486 rem += seconds - tdays * SECSPERDAY; 1487 } 1488 /* 1489 ** Given the range, we can now fearlessly cast... 1490 */ 1491 idays = tdays; 1492 rem += offset - corr; 1493 while (rem < 0) { 1494 rem += SECSPERDAY; 1495 --idays; 1496 } 1497 while (rem >= SECSPERDAY) { 1498 rem -= SECSPERDAY; 1499 ++idays; 1500 } 1501 while (idays < 0) { 1502 if (increment_overflow(&y, -1)) 1503 return NULL; 1504 idays += year_lengths[isleap(y)]; 1505 } 1506 while (idays >= year_lengths[isleap(y)]) { 1507 idays -= year_lengths[isleap(y)]; 1508 if (increment_overflow(&y, 1)) 1509 return NULL; 1510 } 1511 tmp->tm_year = y; 1512 if (increment_overflow(&tmp->tm_year, -TM_YEAR_BASE)) 1513 return NULL; 1514 tmp->tm_yday = idays; 1515 /* 1516 ** The "extra" mods below avoid overflow problems. 1517 */ 1518 tmp->tm_wday = EPOCH_WDAY + 1519 ((y - EPOCH_YEAR) % DAYSPERWEEK) * 1520 (DAYSPERNYEAR % DAYSPERWEEK) + 1521 leaps_thru_end_of(y - 1) - 1522 leaps_thru_end_of(EPOCH_YEAR - 1) + 1523 idays; 1524 tmp->tm_wday %= DAYSPERWEEK; 1525 if (tmp->tm_wday < 0) 1526 tmp->tm_wday += DAYSPERWEEK; 1527 tmp->tm_hour = (int) (rem / SECSPERHOUR); 1528 rem %= SECSPERHOUR; 1529 tmp->tm_min = (int) (rem / SECSPERMIN); 1530 /* 1531 ** A positive leap second requires a special 1532 ** representation. This uses "... ??:59:60" et seq. 1533 */ 1534 tmp->tm_sec = (int) (rem % SECSPERMIN) + hit; 1535 ip = mon_lengths[isleap(y)]; 1536 for (tmp->tm_mon = 0; idays >= ip[tmp->tm_mon]; ++(tmp->tm_mon)) 1537 idays -= ip[tmp->tm_mon]; 1538 tmp->tm_mday = idays + 1; 1539 tmp->tm_isdst = 0; 1540 #ifdef TM_GMTOFF 1541 tmp->TM_GMTOFF = offset; 1542 #endif /* defined TM_GMTOFF */ 1543 return tmp; 1544 } 1545 1546 char * 1547 ctime(const time_t *const timep) 1548 { 1549 /* 1550 ** Section 4.12.3.2 of X3.159-1989 requires that 1551 ** The ctime function converts the calendar time pointed to by timer 1552 ** to local time in the form of a string. It is equivalent to 1553 ** asctime(localtime(timer)) 1554 */ 1555 return asctime(localtime(timep)); 1556 } 1557 1558 char * 1559 ctime_r(const time_t *const timep, char *buf) 1560 { 1561 struct tm mytm; 1562 1563 return asctime_r(localtime_r(timep, &mytm), buf); 1564 } 1565 1566 /* 1567 ** Adapted from code provided by Robert Elz, who writes: 1568 ** The "best" way to do mktime I think is based on an idea of Bob 1569 ** Kridle's (so its said...) from a long time ago. 1570 ** It does a binary search of the time_t space. Since time_t's are 1571 ** just 32 bits, its a max of 32 iterations (even at 64 bits it 1572 ** would still be very reasonable). 1573 */ 1574 1575 #ifndef WRONG 1576 #define WRONG (-1) 1577 #endif /* !defined WRONG */ 1578 1579 /* 1580 ** Normalize logic courtesy Paul Eggert. 1581 */ 1582 1583 static int 1584 increment_overflow(int *const ip, int j) 1585 { 1586 register int const i = *ip; 1587 1588 /* 1589 ** If i >= 0 there can only be overflow if i + j > INT_MAX 1590 ** or if j > INT_MAX - i; given i >= 0, INT_MAX - i cannot overflow. 1591 ** If i < 0 there can only be overflow if i + j < INT_MIN 1592 ** or if j < INT_MIN - i; given i < 0, INT_MIN - i cannot overflow. 1593 */ 1594 if ((i >= 0) ? (j > INT_MAX - i) : (j < INT_MIN - i)) 1595 return true; 1596 *ip += j; 1597 return false; 1598 } 1599 1600 static int 1601 increment_overflow32(int_fast32_t *const lp, int const m) 1602 { 1603 register int_fast32_t const l = *lp; 1604 1605 if ((l >= 0) ? (m > INT_FAST32_MAX - l) : (m < INT_FAST32_MIN - l)) 1606 return true; 1607 *lp += m; 1608 return false; 1609 } 1610 1611 static int 1612 increment_overflow_time(time_t *tp, int_fast32_t j) 1613 { 1614 /* 1615 ** This is like 1616 ** 'if (! (time_t_min <= *tp + j && *tp + j <= time_t_max)) ...', 1617 ** except that it does the right thing even if *tp + j would overflow. 1618 */ 1619 if (! (j < 0 1620 ? (TYPE_SIGNED(time_t) ? time_t_min - j <= *tp : -1 - j < *tp) 1621 : *tp <= time_t_max - j)) 1622 return true; 1623 *tp += j; 1624 return false; 1625 } 1626 1627 static int 1628 normalize_overflow(int *const tensptr, int *const unitsptr, const int base) 1629 { 1630 register int tensdelta; 1631 1632 tensdelta = (*unitsptr >= 0) ? 1633 (*unitsptr / base) : 1634 (-1 - (-1 - *unitsptr) / base); 1635 *unitsptr -= tensdelta * base; 1636 return increment_overflow(tensptr, tensdelta); 1637 } 1638 1639 static int 1640 normalize_overflow32(int_fast32_t *const tensptr, int *const unitsptr, 1641 const int base) 1642 { 1643 register int tensdelta; 1644 1645 tensdelta = (*unitsptr >= 0) ? 1646 (*unitsptr / base) : 1647 (-1 - (-1 - *unitsptr) / base); 1648 *unitsptr -= tensdelta * base; 1649 return increment_overflow32(tensptr, tensdelta); 1650 } 1651 1652 static int 1653 tmcomp(register const struct tm *const atmp, 1654 register const struct tm *const btmp) 1655 { 1656 register int result; 1657 1658 if (atmp->tm_year != btmp->tm_year) 1659 return atmp->tm_year < btmp->tm_year ? -1 : 1; 1660 if ((result = (atmp->tm_mon - btmp->tm_mon)) == 0 && 1661 (result = (atmp->tm_mday - btmp->tm_mday)) == 0 && 1662 (result = (atmp->tm_hour - btmp->tm_hour)) == 0 && 1663 (result = (atmp->tm_min - btmp->tm_min)) == 0) 1664 result = atmp->tm_sec - btmp->tm_sec; 1665 return result; 1666 } 1667 1668 static time_t 1669 time2sub(struct tm *const tmp, 1670 struct tm *(*const funcp)(const time_t *, int_fast32_t, struct tm *), 1671 const int_fast32_t offset, 1672 int *const okayp, 1673 const int do_norm_secs) 1674 { 1675 register const struct state * sp; 1676 register int dir; 1677 register int i, j; 1678 register int saved_seconds; 1679 register int_fast32_t li; 1680 register time_t lo; 1681 register time_t hi; 1682 int_fast32_t y; 1683 time_t newt; 1684 time_t t; 1685 struct tm yourtm, mytm; 1686 1687 *okayp = false; 1688 yourtm = *tmp; 1689 if (do_norm_secs) { 1690 if (normalize_overflow(&yourtm.tm_min, &yourtm.tm_sec, 1691 SECSPERMIN)) 1692 return WRONG; 1693 } 1694 if (normalize_overflow(&yourtm.tm_hour, &yourtm.tm_min, MINSPERHOUR)) 1695 return WRONG; 1696 if (normalize_overflow(&yourtm.tm_mday, &yourtm.tm_hour, HOURSPERDAY)) 1697 return WRONG; 1698 y = yourtm.tm_year; 1699 if (normalize_overflow32(&y, &yourtm.tm_mon, MONSPERYEAR)) 1700 return WRONG; 1701 /* 1702 ** Turn y into an actual year number for now. 1703 ** It is converted back to an offset from TM_YEAR_BASE later. 1704 */ 1705 if (increment_overflow32(&y, TM_YEAR_BASE)) 1706 return WRONG; 1707 while (yourtm.tm_mday <= 0) { 1708 if (increment_overflow32(&y, -1)) 1709 return WRONG; 1710 li = y + (1 < yourtm.tm_mon); 1711 yourtm.tm_mday += year_lengths[isleap(li)]; 1712 } 1713 while (yourtm.tm_mday > DAYSPERLYEAR) { 1714 li = y + (1 < yourtm.tm_mon); 1715 yourtm.tm_mday -= year_lengths[isleap(li)]; 1716 if (increment_overflow32(&y, 1)) 1717 return WRONG; 1718 } 1719 for ( ; ; ) { 1720 i = mon_lengths[isleap(y)][yourtm.tm_mon]; 1721 if (yourtm.tm_mday <= i) 1722 break; 1723 yourtm.tm_mday -= i; 1724 if (++yourtm.tm_mon >= MONSPERYEAR) { 1725 yourtm.tm_mon = 0; 1726 if (increment_overflow32(&y, 1)) 1727 return WRONG; 1728 } 1729 } 1730 if (increment_overflow32(&y, -TM_YEAR_BASE)) 1731 return WRONG; 1732 yourtm.tm_year = y; 1733 if (yourtm.tm_year != y) 1734 return WRONG; 1735 if (yourtm.tm_sec >= 0 && yourtm.tm_sec < SECSPERMIN) 1736 saved_seconds = 0; 1737 else if (y + TM_YEAR_BASE < EPOCH_YEAR) { 1738 /* 1739 ** We can't set tm_sec to 0, because that might push the 1740 ** time below the minimum representable time. 1741 ** Set tm_sec to 59 instead. 1742 ** This assumes that the minimum representable time is 1743 ** not in the same minute that a leap second was deleted from, 1744 ** which is a safer assumption than using 58 would be. 1745 */ 1746 if (increment_overflow(&yourtm.tm_sec, 1 - SECSPERMIN)) 1747 return WRONG; 1748 saved_seconds = yourtm.tm_sec; 1749 yourtm.tm_sec = SECSPERMIN - 1; 1750 } else { 1751 saved_seconds = yourtm.tm_sec; 1752 yourtm.tm_sec = 0; 1753 } 1754 /* 1755 ** Do a binary search (this works whatever time_t's type is). 1756 */ 1757 if (!TYPE_SIGNED(time_t)) { 1758 lo = 0; 1759 hi = lo - 1; 1760 } else { 1761 lo = 1; 1762 for (i = 0; i < (int) TYPE_BIT(time_t) - 1; ++i) 1763 lo *= 2; 1764 hi = -(lo + 1); 1765 } 1766 for ( ; ; ) { 1767 t = lo / 2 + hi / 2; 1768 if (t < lo) 1769 t = lo; 1770 else if (t > hi) 1771 t = hi; 1772 if ((*funcp)(&t, offset, &mytm) == NULL) { 1773 /* 1774 ** Assume that t is too extreme to be represented in 1775 ** a struct tm; arrange things so that it is less 1776 ** extreme on the next pass. 1777 */ 1778 dir = (t > 0) ? 1 : -1; 1779 } else dir = tmcomp(&mytm, &yourtm); 1780 if (dir != 0) { 1781 if (t == lo) { 1782 if (t == time_t_max) 1783 return WRONG; 1784 ++t; 1785 ++lo; 1786 } else if (t == hi) { 1787 if (t == time_t_min) 1788 return WRONG; 1789 --t; 1790 --hi; 1791 } 1792 if (lo > hi) 1793 return WRONG; 1794 if (dir > 0) 1795 hi = t; 1796 else lo = t; 1797 continue; 1798 } 1799 if (yourtm.tm_isdst < 0 || mytm.tm_isdst == yourtm.tm_isdst) 1800 break; 1801 /* 1802 ** Right time, wrong type. 1803 ** Hunt for right time, right type. 1804 ** It's okay to guess wrong since the guess 1805 ** gets checked. 1806 */ 1807 sp = (const struct state *) 1808 ((funcp == localsub) ? lclptr : gmtptr); 1809 if (sp == NULL) 1810 return WRONG; 1811 for (i = sp->typecnt - 1; i >= 0; --i) { 1812 if (sp->ttis[i].tt_isdst != yourtm.tm_isdst) 1813 continue; 1814 for (j = sp->typecnt - 1; j >= 0; --j) { 1815 if (sp->ttis[j].tt_isdst == yourtm.tm_isdst) 1816 continue; 1817 newt = t + sp->ttis[j].tt_gmtoff - 1818 sp->ttis[i].tt_gmtoff; 1819 if ((*funcp)(&newt, offset, &mytm) == NULL) 1820 continue; 1821 if (tmcomp(&mytm, &yourtm) != 0) 1822 continue; 1823 if (mytm.tm_isdst != yourtm.tm_isdst) 1824 continue; 1825 /* 1826 ** We have a match. 1827 */ 1828 t = newt; 1829 goto label; 1830 } 1831 } 1832 return WRONG; 1833 } 1834 label: 1835 newt = t + saved_seconds; 1836 if ((newt < t) != (saved_seconds < 0)) 1837 return WRONG; 1838 t = newt; 1839 if ((*funcp)(&t, offset, tmp)) 1840 *okayp = true; 1841 return t; 1842 } 1843 1844 static time_t 1845 time2(struct tm * const tmp, 1846 struct tm * (*const funcp)(const time_t *, int_fast32_t, struct tm *), 1847 const int_fast32_t offset, 1848 int *const okayp) 1849 { 1850 time_t t; 1851 1852 /* 1853 ** First try without normalization of seconds 1854 ** (in case tm_sec contains a value associated with a leap second). 1855 ** If that fails, try with normalization of seconds. 1856 */ 1857 t = time2sub(tmp, funcp, offset, okayp, false); 1858 return *okayp ? t : time2sub(tmp, funcp, offset, okayp, true); 1859 } 1860 1861 static time_t 1862 time1(struct tm *const tmp, 1863 struct tm *(*const funcp) (const time_t *, int_fast32_t, struct tm *), 1864 const int_fast32_t offset) 1865 { 1866 register time_t t; 1867 register const struct state * sp; 1868 register int samei, otheri; 1869 register int sameind, otherind; 1870 register int i; 1871 register int nseen; 1872 int seen[TZ_MAX_TYPES]; 1873 int types[TZ_MAX_TYPES]; 1874 int okay; 1875 1876 if (tmp == NULL) { 1877 errno = EINVAL; 1878 return WRONG; 1879 } 1880 if (tmp->tm_isdst > 1) 1881 tmp->tm_isdst = 1; 1882 t = time2(tmp, funcp, offset, &okay); 1883 if (okay) 1884 return t; 1885 if (tmp->tm_isdst < 0) 1886 #ifdef PCTS 1887 /* 1888 ** POSIX Conformance Test Suite code courtesy Grant Sullivan. 1889 */ 1890 tmp->tm_isdst = 0; /* reset to std and try again */ 1891 #else 1892 return t; 1893 #endif /* !defined PCTS */ 1894 /* 1895 ** We're supposed to assume that somebody took a time of one type 1896 ** and did some math on it that yielded a "struct tm" that's bad. 1897 ** We try to divine the type they started from and adjust to the 1898 ** type they need. 1899 */ 1900 sp = (const struct state *) ((funcp == localsub) ? lclptr : gmtptr); 1901 if (sp == NULL) 1902 return WRONG; 1903 for (i = 0; i < sp->typecnt; ++i) 1904 seen[i] = false; 1905 nseen = 0; 1906 for (i = sp->timecnt - 1; i >= 0; --i) 1907 if (!seen[sp->types[i]]) { 1908 seen[sp->types[i]] = true; 1909 types[nseen++] = sp->types[i]; 1910 } 1911 for (sameind = 0; sameind < nseen; ++sameind) { 1912 samei = types[sameind]; 1913 if (sp->ttis[samei].tt_isdst != tmp->tm_isdst) 1914 continue; 1915 for (otherind = 0; otherind < nseen; ++otherind) { 1916 otheri = types[otherind]; 1917 if (sp->ttis[otheri].tt_isdst == tmp->tm_isdst) 1918 continue; 1919 tmp->tm_sec += sp->ttis[otheri].tt_gmtoff - 1920 sp->ttis[samei].tt_gmtoff; 1921 tmp->tm_isdst = !tmp->tm_isdst; 1922 t = time2(tmp, funcp, offset, &okay); 1923 if (okay) 1924 return t; 1925 tmp->tm_sec -= sp->ttis[otheri].tt_gmtoff - 1926 sp->ttis[samei].tt_gmtoff; 1927 tmp->tm_isdst = !tmp->tm_isdst; 1928 } 1929 } 1930 return WRONG; 1931 } 1932 1933 time_t 1934 mktime(struct tm *const tmp) 1935 { 1936 tzset(); 1937 return time1(tmp, localsub, 0L); 1938 } 1939 1940 #ifdef STD_INSPIRED 1941 1942 time_t 1943 timelocal(struct tm *const tmp) 1944 { 1945 if (tmp != NULL) 1946 tmp->tm_isdst = -1; /* in case it wasn't initialized */ 1947 return mktime(tmp); 1948 } 1949 1950 time_t 1951 timegm(struct tm *const tmp) 1952 { 1953 if (tmp != NULL) 1954 tmp->tm_isdst = 0; 1955 return time1(tmp, gmtsub, 0L); 1956 } 1957 1958 time_t 1959 timeoff(struct tm *const tmp, const long offset) 1960 { 1961 if (tmp != NULL) 1962 tmp->tm_isdst = 0; 1963 return time1(tmp, gmtsub, offset); 1964 } 1965 1966 #endif /* defined STD_INSPIRED */ 1967 1968 #ifdef CMUCS 1969 1970 /* 1971 ** The following is supplied for compatibility with 1972 ** previous versions of the CMUCS runtime library. 1973 */ 1974 1975 long 1976 gtime(struct tm *const tmp) 1977 { 1978 const time_t t = mktime(tmp); 1979 1980 if (t == WRONG) 1981 return -1; 1982 return t; 1983 } 1984 1985 #endif /* defined CMUCS */ 1986 1987 /* 1988 ** XXX--is the below the right way to conditionalize?? 1989 */ 1990 1991 #ifdef STD_INSPIRED 1992 1993 /* 1994 ** IEEE Std 1003.1-1988 (POSIX) legislates that 536457599 1995 ** shall correspond to "Wed Dec 31 23:59:59 UTC 1986", which 1996 ** is not the case if we are accounting for leap seconds. 1997 ** So, we provide the following conversion routines for use 1998 ** when exchanging timestamps with POSIX conforming systems. 1999 */ 2000 2001 static int_fast64_t 2002 leapcorr(time_t *timep) 2003 { 2004 register struct state * sp; 2005 register struct lsinfo * lp; 2006 register int i; 2007 2008 sp = lclptr; 2009 i = sp->leapcnt; 2010 while (--i >= 0) { 2011 lp = &sp->lsis[i]; 2012 if (*timep >= lp->ls_trans) 2013 return lp->ls_corr; 2014 } 2015 return 0; 2016 } 2017 2018 time_t 2019 time2posix(time_t t) 2020 { 2021 tzset(); 2022 return t - leapcorr(&t); 2023 } 2024 2025 time_t 2026 posix2time(time_t t) 2027 { 2028 time_t x; 2029 time_t y; 2030 2031 tzset(); 2032 /* 2033 ** For a positive leap second hit, the result 2034 ** is not unique. For a negative leap second 2035 ** hit, the corresponding time doesn't exist, 2036 ** so we return an adjacent second. 2037 */ 2038 x = t + leapcorr(&t); 2039 y = x - leapcorr(&x); 2040 if (y < t) { 2041 do { 2042 x++; 2043 y = x - leapcorr(&x); 2044 } while (y < t); 2045 if (t != y) 2046 return x - 1; 2047 } else if (y > t) { 2048 do { 2049 --x; 2050 y = x - leapcorr(&x); 2051 } while (y > t); 2052 if (t != y) 2053 return x + 1; 2054 } 2055 return x; 2056 } 2057 2058 #endif /* defined STD_INSPIRED */