1 /* 2 ** This file is in the public domain, so clarified as of 3 ** 1996-06-05 by Arthur David Olson. 4 ** 5 ** @(#)localtime.c 8.9 6 ** $FreeBSD: src/lib/libc/stdtime/localtime.c,v 1.25.2.2 2002/08/13 16:08:07 bmilekic Exp $ 7 ** $DragonFly: src/lib/libc/stdtime/localtime.c,v 1.7 2008/10/19 20:15:58 swildner Exp $ 8 */ 9 10 /* 11 ** Leap second handling from Bradley White. 12 ** POSIX-style TZ environment variable handling from Guy Harris. 13 */ 14 15 /*LINTLIBRARY*/ 16 17 #include "namespace.h" 18 #include <sys/types.h> 19 #include <sys/stat.h> 20 21 #include <fcntl.h> 22 #include <float.h> /* for FLT_MAX and DBL_MAX */ 23 #include <time.h> 24 #include <pthread.h> 25 #include "private.h" 26 #include <un-namespace.h> 27 28 #include "tzfile.h" 29 30 #include "libc_private.h" 31 32 #define _MUTEX_LOCK(x) if (__isthreaded) _pthread_mutex_lock(x) 33 #define _MUTEX_UNLOCK(x) if (__isthreaded) _pthread_mutex_unlock(x) 34 35 #ifndef TZ_ABBR_MAX_LEN 36 #define TZ_ABBR_MAX_LEN 16 37 #endif /* !defined TZ_ABBR_MAX_LEN */ 38 39 #ifndef TZ_ABBR_CHAR_SET 40 #define TZ_ABBR_CHAR_SET \ 41 "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789 :+-._" 42 #endif /* !defined TZ_ABBR_CHAR_SET */ 43 44 #ifndef TZ_ABBR_ERR_CHAR 45 #define TZ_ABBR_ERR_CHAR '_' 46 #endif /* !defined TZ_ABBR_ERR_CHAR */ 47 48 /* 49 ** Someone might make incorrect use of a time zone abbreviation: 50 ** 1. They might reference tzname[0] before calling tzset (explicitly 51 ** or implicitly). 52 ** 2. They might reference tzname[1] before calling tzset (explicitly 53 ** or implicitly). 54 ** 3. They might reference tzname[1] after setting to a time zone 55 ** in which Daylight Saving Time is never observed. 56 ** 4. They might reference tzname[0] after setting to a time zone 57 ** in which Standard Time is never observed. 58 ** 5. They might reference tm.TM_ZONE after calling offtime. 59 ** What's best to do in the above cases is open to debate; 60 ** for now, we just set things up so that in any of the five cases 61 ** WILDABBR is used. Another possibility: initialize tzname[0] to the 62 ** string "tzname[0] used before set", and similarly for the other cases. 63 ** And another: initialize tzname[0] to "ERA", with an explanation in the 64 ** manual page of what this "time zone abbreviation" means (doing this so 65 ** that tzname[0] has the "normal" length of three characters). 66 */ 67 #define WILDABBR " " 68 69 static char wildabbr[] = WILDABBR; 70 71 static const char gmt[] = "UTC"; 72 73 /* 74 ** The DST rules to use if TZ has no rules and we can't load TZDEFRULES. 75 ** We default to US rules as of 1999-08-17. 76 ** POSIX 1003.1 section 8.1.1 says that the default DST rules are 77 ** implementation dependent; for historical reasons, US rules are a 78 ** common default. 79 */ 80 #ifndef TZDEFRULESTRING 81 #define TZDEFRULESTRING ",M4.1.0,M10.5.0" 82 #endif /* !defined TZDEFDST */ 83 84 struct ttinfo { /* time type information */ 85 long tt_gmtoff; /* UTC offset in seconds */ 86 int tt_isdst; /* used to set tm_isdst */ 87 int tt_abbrind; /* abbreviation list index */ 88 int tt_ttisstd; /* TRUE if transition is std time */ 89 int tt_ttisgmt; /* TRUE if transition is UTC */ 90 }; 91 92 struct lsinfo { /* leap second information */ 93 time_t ls_trans; /* transition time */ 94 long ls_corr; /* correction to apply */ 95 }; 96 97 #define BIGGEST(a, b) (((a) > (b)) ? (a) : (b)) 98 99 #ifdef TZNAME_MAX 100 #define MY_TZNAME_MAX TZNAME_MAX 101 #endif /* defined TZNAME_MAX */ 102 #ifndef TZNAME_MAX 103 #define MY_TZNAME_MAX 255 104 #endif /* !defined TZNAME_MAX */ 105 106 struct state { 107 int leapcnt; 108 int timecnt; 109 int typecnt; 110 int charcnt; 111 int goback; 112 int goahead; 113 time_t ats[TZ_MAX_TIMES]; 114 unsigned char types[TZ_MAX_TIMES]; 115 struct ttinfo ttis[TZ_MAX_TYPES]; 116 char chars[BIGGEST(BIGGEST(TZ_MAX_CHARS + 1, sizeof gmt), 117 (2 * (MY_TZNAME_MAX + 1)))]; 118 struct lsinfo lsis[TZ_MAX_LEAPS]; 119 }; 120 121 struct rule { 122 int r_type; /* type of rule--see below */ 123 int r_day; /* day number of rule */ 124 int r_week; /* week number of rule */ 125 int r_mon; /* month number of rule */ 126 long r_time; /* transition time of rule */ 127 }; 128 129 #define JULIAN_DAY 0 /* Jn - Julian day */ 130 #define DAY_OF_YEAR 1 /* n - day of year */ 131 #define MONTH_NTH_DAY_OF_WEEK 2 /* Mm.n.d - month, week, day of week */ 132 133 /* 134 ** Prototypes for static functions. 135 */ 136 137 static long detzcode(const char * codep); 138 static time_t detzcode64(const char * codep); 139 static int differ_by_repeat(time_t t1, time_t t0); 140 static const char * getzname(const char * strp); 141 static const char * getqzname(const char * strp, const int delim); 142 static const char * getnum(const char * strp, int * nump, int min, 143 int max); 144 static const char * getsecs(const char * strp, long * secsp); 145 static const char * getoffset(const char * strp, long * offsetp); 146 static const char * getrule(const char * strp, struct rule * rulep); 147 static void gmtload(struct state * sp); 148 static struct tm * gmtsub(const time_t * timep, long offset, 149 struct tm * tmp); 150 static struct tm * localsub(const time_t * timep, long offset, 151 struct tm * tmp); 152 static int increment_overflow(int * number, int delta); 153 static int leaps_thru_end_of(int y); 154 static int long_increment_overflow(long * number, int delta); 155 static int long_normalize_overflow(long * 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 long, struct tm *), 163 long offset); 164 static time_t time2(struct tm *tmp, 165 struct tm * (*funcp)(const time_t *, 166 long, struct tm*), 167 long offset, int * okayp); 168 static time_t time2sub(struct tm *tmp, 169 struct tm * (*funcp)(const time_t *, 170 long, struct tm*), 171 long offset, int * okayp, int do_norm_secs); 172 static struct tm * timesub(const time_t * timep, long offset, 173 const struct state * sp, struct tm * tmp); 174 static int tmcomp(const struct tm * atmp, 175 const struct tm * btmp); 176 static time_t transtime(time_t janfirst, int year, 177 const struct rule * rulep, long offset); 178 static int typesequiv(const struct state * sp, int a, int b); 179 static int tzload(const char * name, struct state * sp, 180 int doextend); 181 static int tzparse(const char * name, struct state * sp, 182 int lastditch); 183 184 static struct state lclmem; 185 static struct state gmtmem; 186 #define lclptr (&lclmem) 187 #define gmtptr (&gmtmem) 188 189 #ifndef TZ_STRLEN_MAX 190 #define TZ_STRLEN_MAX 255 191 #endif /* !defined TZ_STRLEN_MAX */ 192 193 static char lcl_TZname[TZ_STRLEN_MAX + 1]; 194 static int lcl_is_set; 195 static int gmt_is_set; 196 static pthread_mutex_t lcl_mutex = PTHREAD_MUTEX_INITIALIZER; 197 static pthread_mutex_t gmt_mutex = PTHREAD_MUTEX_INITIALIZER; 198 199 char * tzname[2] = { 200 wildabbr, 201 wildabbr 202 }; 203 204 /* 205 ** Section 4.12.3 of X3.159-1989 requires that 206 ** Except for the strftime function, these functions [asctime, 207 ** ctime, gmtime, localtime] return values in one of two static 208 ** objects: a broken-down time structure and an array of char. 209 ** Thanks to Paul Eggert for noting this. 210 */ 211 212 static struct tm tm; 213 214 time_t timezone = 0; 215 int daylight = 0; 216 217 static long 218 detzcode(const char * const codep) 219 { 220 long result; 221 int i; 222 223 result = (codep[0] & 0x80) ? ~0L : 0; 224 for (i = 0; i < 4; ++i) 225 result = (result << 8) | (codep[i] & 0xff); 226 return result; 227 } 228 229 static time_t 230 detzcode64(const char * const codep) 231 { 232 time_t result; 233 int i; 234 235 result = (codep[0] & 0x80) ? (~(int_fast64_t) 0) : 0; 236 for (i = 0; i < 8; ++i) 237 result = result * 256 + (codep[i] & 0xff); 238 return result; 239 } 240 241 static void 242 settzname(void) 243 { 244 struct state * const sp = lclptr; 245 int i; 246 247 tzname[0] = wildabbr; 248 tzname[1] = wildabbr; 249 daylight = 0; 250 timezone = 0; 251 252 for (i = 0; i < sp->typecnt; ++i) { 253 const struct ttinfo * const ttisp = &sp->ttis[i]; 254 255 tzname[ttisp->tt_isdst] = 256 &sp->chars[ttisp->tt_abbrind]; 257 if (ttisp->tt_isdst) 258 daylight = 1; 259 if (i == 0 || !ttisp->tt_isdst) 260 timezone = -(ttisp->tt_gmtoff); 261 } 262 /* 263 ** And to get the latest zone names into tzname. . . 264 */ 265 for (i = 0; i < sp->timecnt; ++i) { 266 const struct ttinfo * const ttisp = 267 &sp->ttis[ 268 sp->types[i]]; 269 270 tzname[ttisp->tt_isdst] = 271 &sp->chars[ttisp->tt_abbrind]; 272 } 273 /* 274 ** Finally, scrub the abbreviations. 275 ** First, replace bogus characters. 276 */ 277 for (i = 0; i < sp->charcnt; ++i) 278 if (strchr(TZ_ABBR_CHAR_SET, sp->chars[i]) == NULL) 279 sp->chars[i] = TZ_ABBR_ERR_CHAR; 280 /* 281 ** Second, truncate long abbreviations. 282 */ 283 for (i = 0; i < sp->typecnt; ++i) { 284 const struct ttinfo * const ttisp = &sp->ttis[i]; 285 char * cp = &sp->chars[ttisp->tt_abbrind]; 286 287 if (strlen(cp) > TZ_ABBR_MAX_LEN && 288 strcmp(cp, GRANDPARENTED) != 0) 289 *(cp + TZ_ABBR_MAX_LEN) = '\0'; 290 } 291 } 292 293 static int 294 differ_by_repeat(const time_t t1, const time_t t0) 295 { 296 if (TYPE_INTEGRAL(time_t) && 297 TYPE_BIT(time_t) - TYPE_SIGNED(time_t) < SECSPERREPEAT_BITS) 298 return 0; 299 return t1 - t0 == SECSPERREPEAT; 300 } 301 302 static int 303 tzload(const char *name, struct state * const sp, const int doextend) 304 { 305 const char * p; 306 int i; 307 int fid; 308 int stored; 309 int nread; 310 union { 311 struct tzhead tzhead; 312 char buf[2 * sizeof(struct tzhead) + 313 2 * sizeof *sp + 314 4 * TZ_MAX_TIMES]; 315 } u; 316 317 /* XXX The following is from OpenBSD, and I'm not sure it is correct */ 318 if (name != NULL && issetugid() != 0) 319 if ((name[0] == ':' && name[1] == '/') || 320 name[0] == '/' || strchr(name, '.')) 321 name = NULL; 322 if (name == NULL && (name = TZDEFAULT) == NULL) 323 return -1; 324 { 325 int doaccess; 326 struct stat stab; 327 /* 328 ** Section 4.9.1 of the C standard says that 329 ** "FILENAME_MAX expands to an integral constant expression 330 ** that is the size needed for an array of char large enough 331 ** to hold the longest file name string that the implementation 332 ** guarantees can be opened." 333 */ 334 char fullname[FILENAME_MAX + 1]; 335 336 if (name[0] == ':') 337 ++name; 338 doaccess = name[0] == '/'; 339 if (!doaccess) { 340 if ((p = TZDIR) == NULL) 341 return -1; 342 if ((strlen(p) + 1 + strlen(name) + 1) >= sizeof fullname) 343 return -1; 344 strcpy(fullname, p); 345 strcat(fullname, "/"); 346 strcat(fullname, name); 347 /* 348 ** Set doaccess if '.' (as in "../") shows up in name. 349 */ 350 if (strchr(name, '.') != NULL) 351 doaccess = TRUE; 352 name = fullname; 353 } 354 if (doaccess && access(name, R_OK) != 0) 355 return -1; 356 if ((fid = _open(name, O_RDONLY)) == -1) 357 return -1; 358 if ((_fstat(fid, &stab) < 0) || !S_ISREG(stab.st_mode)) { 359 _close(fid); 360 return -1; 361 } 362 } 363 nread = read(fid, u.buf, sizeof u.buf); 364 if (close(fid) < 0 || nread <= 0) 365 return -1; 366 for (stored = 4; stored <= 8; stored *= 2) { 367 int ttisstdcnt; 368 int ttisgmtcnt; 369 370 ttisstdcnt = (int) detzcode(u.tzhead.tzh_ttisstdcnt); 371 ttisgmtcnt = (int) detzcode(u.tzhead.tzh_ttisgmtcnt); 372 sp->leapcnt = (int) detzcode(u.tzhead.tzh_leapcnt); 373 sp->timecnt = (int) detzcode(u.tzhead.tzh_timecnt); 374 sp->typecnt = (int) detzcode(u.tzhead.tzh_typecnt); 375 sp->charcnt = (int) detzcode(u.tzhead.tzh_charcnt); 376 p = u.tzhead.tzh_charcnt + sizeof u.tzhead.tzh_charcnt; 377 if (sp->leapcnt < 0 || sp->leapcnt > TZ_MAX_LEAPS || 378 sp->typecnt <= 0 || sp->typecnt > TZ_MAX_TYPES || 379 sp->timecnt < 0 || sp->timecnt > TZ_MAX_TIMES || 380 sp->charcnt < 0 || sp->charcnt > TZ_MAX_CHARS || 381 (ttisstdcnt != sp->typecnt && ttisstdcnt != 0) || 382 (ttisgmtcnt != sp->typecnt && ttisgmtcnt != 0)) 383 return -1; 384 if (nread - (p - u.buf) < 385 sp->timecnt * stored + /* ats */ 386 sp->timecnt + /* types */ 387 sp->typecnt * 6 + /* ttinfos */ 388 sp->charcnt + /* chars */ 389 sp->leapcnt * (stored + 4) + /* lsinfos */ 390 ttisstdcnt + /* ttisstds */ 391 ttisgmtcnt) /* ttisgmts */ 392 return -1; 393 for (i = 0; i < sp->timecnt; ++i) { 394 sp->ats[i] = (stored == 4) ? 395 detzcode(p) : detzcode64(p); 396 p += stored; 397 } 398 for (i = 0; i < sp->timecnt; ++i) { 399 sp->types[i] = (unsigned char) *p++; 400 if (sp->types[i] >= sp->typecnt) 401 return -1; 402 } 403 for (i = 0; i < sp->typecnt; ++i) { 404 struct ttinfo * ttisp; 405 406 ttisp = &sp->ttis[i]; 407 ttisp->tt_gmtoff = detzcode(p); 408 p += 4; 409 ttisp->tt_isdst = (unsigned char) *p++; 410 if (ttisp->tt_isdst != 0 && ttisp->tt_isdst != 1) 411 return -1; 412 ttisp->tt_abbrind = (unsigned char) *p++; 413 if (ttisp->tt_abbrind < 0 || 414 ttisp->tt_abbrind > sp->charcnt) 415 return -1; 416 } 417 for (i = 0; i < sp->charcnt; ++i) 418 sp->chars[i] = *p++; 419 sp->chars[i] = '\0'; /* ensure '\0' at end */ 420 for (i = 0; i < sp->leapcnt; ++i) { 421 struct lsinfo * lsisp; 422 423 lsisp = &sp->lsis[i]; 424 lsisp->ls_trans = (stored == 4) ? 425 detzcode(p) : detzcode64(p); 426 p += stored; 427 lsisp->ls_corr = detzcode(p); 428 p += 4; 429 } 430 for (i = 0; i < sp->typecnt; ++i) { 431 struct ttinfo * ttisp; 432 433 ttisp = &sp->ttis[i]; 434 if (ttisstdcnt == 0) 435 ttisp->tt_ttisstd = FALSE; 436 else { 437 ttisp->tt_ttisstd = *p++; 438 if (ttisp->tt_ttisstd != TRUE && 439 ttisp->tt_ttisstd != FALSE) 440 return -1; 441 } 442 } 443 for (i = 0; i < sp->typecnt; ++i) { 444 struct ttinfo * ttisp; 445 446 ttisp = &sp->ttis[i]; 447 if (ttisgmtcnt == 0) 448 ttisp->tt_ttisgmt = FALSE; 449 else { 450 ttisp->tt_ttisgmt = *p++; 451 if (ttisp->tt_ttisgmt != TRUE && 452 ttisp->tt_ttisgmt != FALSE) 453 return -1; 454 } 455 } 456 /* 457 ** Out-of-sort ats should mean we're running on a 458 ** signed time_t system but using a data file with 459 ** unsigned values (or vice versa). 460 */ 461 for (i = 0; i < sp->timecnt - 2; ++i) 462 if (sp->ats[i] > sp->ats[i + 1]) { 463 ++i; 464 if (TYPE_SIGNED(time_t)) { 465 /* 466 ** Ignore the end (easy). 467 */ 468 sp->timecnt = i; 469 } else { 470 /* 471 ** Ignore the beginning (harder). 472 */ 473 int j; 474 475 for (j = 0; j + i < sp->timecnt; ++j) { 476 sp->ats[j] = sp->ats[j + i]; 477 sp->types[j] = sp->types[j + i]; 478 } 479 sp->timecnt = j; 480 } 481 break; 482 } 483 /* 484 ** If this is an old file, we're done. 485 */ 486 if (u.tzhead.tzh_version[0] == '\0') 487 break; 488 nread -= p - u.buf; 489 for (i = 0; i < nread; ++i) 490 u.buf[i] = p[i]; 491 /* 492 ** If this is a narrow integer time_t system, we're done. 493 */ 494 if (stored >= (int) sizeof(time_t) && TYPE_INTEGRAL(time_t)) 495 break; 496 } 497 if (doextend && nread > 2 && 498 u.buf[0] == '\n' && u.buf[nread - 1] == '\n' && 499 sp->typecnt + 2 <= TZ_MAX_TYPES) { 500 struct state ts; 501 int result; 502 503 u.buf[nread - 1] = '\0'; 504 result = tzparse(&u.buf[1], &ts, FALSE); 505 if (result == 0 && ts.typecnt == 2 && 506 sp->charcnt + ts.charcnt <= TZ_MAX_CHARS) { 507 for (i = 0; i < 2; ++i) 508 ts.ttis[i].tt_abbrind += 509 sp->charcnt; 510 for (i = 0; i < ts.charcnt; ++i) 511 sp->chars[sp->charcnt++] = 512 ts.chars[i]; 513 i = 0; 514 while (i < ts.timecnt && 515 ts.ats[i] <= 516 sp->ats[sp->timecnt - 1]) 517 ++i; 518 while (i < ts.timecnt && 519 sp->timecnt < TZ_MAX_TIMES) { 520 sp->ats[sp->timecnt] = 521 ts.ats[i]; 522 sp->types[sp->timecnt] = 523 sp->typecnt + 524 ts.types[i]; 525 ++sp->timecnt; 526 ++i; 527 } 528 sp->ttis[sp->typecnt++] = ts.ttis[0]; 529 sp->ttis[sp->typecnt++] = ts.ttis[1]; 530 } 531 } 532 sp->goback = sp->goahead = FALSE; 533 if (sp->timecnt > 1) { 534 for (i = 1; i < sp->timecnt; ++i) 535 if (typesequiv(sp, sp->types[i], sp->types[0]) && 536 differ_by_repeat(sp->ats[i], sp->ats[0])) { 537 sp->goback = TRUE; 538 break; 539 } 540 for (i = sp->timecnt - 2; i >= 0; --i) 541 if (typesequiv(sp, sp->types[sp->timecnt - 1], 542 sp->types[i]) && 543 differ_by_repeat(sp->ats[sp->timecnt - 1], 544 sp->ats[i])) { 545 sp->goahead = TRUE; 546 break; 547 } 548 } 549 return 0; 550 } 551 552 static int 553 typesequiv(const struct state * const sp, const int a, const int b) 554 { 555 int result; 556 557 if (sp == NULL || 558 a < 0 || a >= sp->typecnt || 559 b < 0 || b >= sp->typecnt) 560 result = FALSE; 561 else { 562 const struct ttinfo * ap = &sp->ttis[a]; 563 const struct ttinfo * bp = &sp->ttis[b]; 564 result = ap->tt_gmtoff == bp->tt_gmtoff && 565 ap->tt_isdst == bp->tt_isdst && 566 ap->tt_ttisstd == bp->tt_ttisstd && 567 ap->tt_ttisgmt == bp->tt_ttisgmt && 568 strcmp(&sp->chars[ap->tt_abbrind], 569 &sp->chars[bp->tt_abbrind]) == 0; 570 } 571 return result; 572 } 573 574 static const int mon_lengths[2][MONSPERYEAR] = { 575 { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }, 576 { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 } 577 }; 578 579 static const int year_lengths[2] = { 580 DAYSPERNYEAR, DAYSPERLYEAR 581 }; 582 583 /* 584 ** Given a pointer into a time zone string, scan until a character that is not 585 ** a valid character in a zone name is found. Return a pointer to that 586 ** character. 587 */ 588 589 static const char * 590 getzname(const char *strp) 591 { 592 char c; 593 594 while ((c = *strp) != '\0' && !is_digit(c) && c != ',' && c != '-' && 595 c != '+') 596 ++strp; 597 return strp; 598 } 599 600 /* 601 ** Given a pointer into an extended time zone string, scan until the ending 602 ** delimiter of the zone name is located. Return a pointer to the delimiter. 603 ** 604 ** As with getzname above, the legal character set is actually quite 605 ** restricted, with other characters producing undefined results. 606 ** We don't do any checking here; checking is done later in common-case code. 607 */ 608 609 static const char * 610 getqzname(const char *strp, const int delim) 611 { 612 int c; 613 614 while ((c = *strp) != '\0' && c != delim) 615 ++strp; 616 return strp; 617 } 618 619 /* 620 ** Given a pointer into a time zone string, extract a number from that string. 621 ** Check that the number is within a specified range; if it is not, return 622 ** NULL. 623 ** Otherwise, return a pointer to the first character not part of the number. 624 */ 625 626 static const char * 627 getnum(const char *strp, int * const nump, const int min, const int max) 628 { 629 char c; 630 int num; 631 632 if (strp == NULL || !is_digit(c = *strp)) 633 return NULL; 634 num = 0; 635 do { 636 num = num * 10 + (c - '0'); 637 if (num > max) 638 return NULL; /* illegal value */ 639 c = *++strp; 640 } while (is_digit(c)); 641 if (num < min) 642 return NULL; /* illegal value */ 643 *nump = num; 644 return strp; 645 } 646 647 /* 648 ** Given a pointer into a time zone string, extract a number of seconds, 649 ** in hh[:mm[:ss]] form, from the string. 650 ** If any error occurs, return NULL. 651 ** Otherwise, return a pointer to the first character not part of the number 652 ** of seconds. 653 */ 654 655 static const char * 656 getsecs(const char *strp, long * const secsp) 657 { 658 int num; 659 660 /* 661 ** `HOURSPERDAY * DAYSPERWEEK - 1' allows quasi-Posix rules like 662 ** "M10.4.6/26", which does not conform to Posix, 663 ** but which specifies the equivalent of 664 ** ``02:00 on the first Sunday on or after 23 Oct''. 665 */ 666 strp = getnum(strp, &num, 0, HOURSPERDAY * DAYSPERWEEK - 1); 667 if (strp == NULL) 668 return NULL; 669 *secsp = num * (long) SECSPERHOUR; 670 if (*strp == ':') { 671 ++strp; 672 strp = getnum(strp, &num, 0, MINSPERHOUR - 1); 673 if (strp == NULL) 674 return NULL; 675 *secsp += num * SECSPERMIN; 676 if (*strp == ':') { 677 ++strp; 678 /* `SECSPERMIN' allows for leap seconds. */ 679 strp = getnum(strp, &num, 0, SECSPERMIN); 680 if (strp == NULL) 681 return NULL; 682 *secsp += num; 683 } 684 } 685 return strp; 686 } 687 688 /* 689 ** Given a pointer into a time zone string, extract an offset, in 690 ** [+-]hh[:mm[:ss]] form, from the string. 691 ** If any error occurs, return NULL. 692 ** Otherwise, return a pointer to the first character not part of the time. 693 */ 694 695 static const char * 696 getoffset(const char *strp, long * const offsetp) 697 { 698 int neg = 0; 699 700 if (*strp == '-') { 701 neg = 1; 702 ++strp; 703 } else if (*strp == '+') 704 ++strp; 705 strp = getsecs(strp, offsetp); 706 if (strp == NULL) 707 return NULL; /* illegal time */ 708 if (neg) 709 *offsetp = -*offsetp; 710 return strp; 711 } 712 713 /* 714 ** Given a pointer into a time zone string, extract a rule in the form 715 ** date[/time]. See POSIX section 8 for the format of "date" and "time". 716 ** If a valid rule is not found, return NULL. 717 ** Otherwise, return a pointer to the first character not part of the rule. 718 */ 719 720 static const char * 721 getrule(const char *strp, struct rule * const rulep) 722 { 723 if (*strp == 'J') { 724 /* 725 ** Julian day. 726 */ 727 rulep->r_type = JULIAN_DAY; 728 ++strp; 729 strp = getnum(strp, &rulep->r_day, 1, DAYSPERNYEAR); 730 } else if (*strp == 'M') { 731 /* 732 ** Month, week, day. 733 */ 734 rulep->r_type = MONTH_NTH_DAY_OF_WEEK; 735 ++strp; 736 strp = getnum(strp, &rulep->r_mon, 1, MONSPERYEAR); 737 if (strp == NULL) 738 return NULL; 739 if (*strp++ != '.') 740 return NULL; 741 strp = getnum(strp, &rulep->r_week, 1, 5); 742 if (strp == NULL) 743 return NULL; 744 if (*strp++ != '.') 745 return NULL; 746 strp = getnum(strp, &rulep->r_day, 0, DAYSPERWEEK - 1); 747 } else if (is_digit(*strp)) { 748 /* 749 ** Day of year. 750 */ 751 rulep->r_type = DAY_OF_YEAR; 752 strp = getnum(strp, &rulep->r_day, 0, DAYSPERLYEAR - 1); 753 } else return NULL; /* invalid format */ 754 if (strp == NULL) 755 return NULL; 756 if (*strp == '/') { 757 /* 758 ** Time specified. 759 */ 760 ++strp; 761 strp = getsecs(strp, &rulep->r_time); 762 } else rulep->r_time = 2 * SECSPERHOUR; /* default = 2:00:00 */ 763 return strp; 764 } 765 766 /* 767 ** Given the Epoch-relative time of January 1, 00:00:00 UTC, in a year, the 768 ** year, a rule, and the offset from UTC at the time that rule takes effect, 769 ** calculate the Epoch-relative time that rule takes effect. 770 */ 771 772 static time_t 773 transtime(const time_t janfirst, const int year, 774 const struct rule * const rulep, const long offset) 775 { 776 int leapyear; 777 time_t value; 778 int i; 779 int d, m1, yy0, yy1, yy2, dow; 780 781 INITIALIZE(value); 782 leapyear = isleap(year); 783 switch (rulep->r_type) { 784 785 case JULIAN_DAY: 786 /* 787 ** Jn - Julian day, 1 == January 1, 60 == March 1 even in leap 788 ** years. 789 ** In non-leap years, or if the day number is 59 or less, just 790 ** add SECSPERDAY times the day number-1 to the time of 791 ** January 1, midnight, to get the day. 792 */ 793 value = janfirst + (rulep->r_day - 1) * SECSPERDAY; 794 if (leapyear && rulep->r_day >= 60) 795 value += SECSPERDAY; 796 break; 797 798 case DAY_OF_YEAR: 799 /* 800 ** n - day of year. 801 ** Just add SECSPERDAY times the day number to the time of 802 ** January 1, midnight, to get the day. 803 */ 804 value = janfirst + rulep->r_day * SECSPERDAY; 805 break; 806 807 case MONTH_NTH_DAY_OF_WEEK: 808 /* 809 ** Mm.n.d - nth "dth day" of month m. 810 */ 811 value = janfirst; 812 for (i = 0; i < rulep->r_mon - 1; ++i) 813 value += mon_lengths[leapyear][i] * SECSPERDAY; 814 815 /* 816 ** Use Zeller's Congruence to get day-of-week of first day of 817 ** month. 818 */ 819 m1 = (rulep->r_mon + 9) % 12 + 1; 820 yy0 = (rulep->r_mon <= 2) ? (year - 1) : year; 821 yy1 = yy0 / 100; 822 yy2 = yy0 % 100; 823 dow = ((26 * m1 - 2) / 10 + 824 1 + yy2 + yy2 / 4 + yy1 / 4 - 2 * yy1) % 7; 825 if (dow < 0) 826 dow += DAYSPERWEEK; 827 828 /* 829 ** "dow" is the day-of-week of the first day of the month. Get 830 ** the day-of-month (zero-origin) of the first "dow" day of the 831 ** month. 832 */ 833 d = rulep->r_day - dow; 834 if (d < 0) 835 d += DAYSPERWEEK; 836 for (i = 1; i < rulep->r_week; ++i) { 837 if (d + DAYSPERWEEK >= 838 mon_lengths[leapyear][rulep->r_mon - 1]) 839 break; 840 d += DAYSPERWEEK; 841 } 842 843 /* 844 ** "d" is the day-of-month (zero-origin) of the day we want. 845 */ 846 value += d * SECSPERDAY; 847 break; 848 } 849 850 /* 851 ** "value" is the Epoch-relative time of 00:00:00 UTC on the day in 852 ** question. To get the Epoch-relative time of the specified local 853 ** time on that day, add the transition time and the current offset 854 ** from UTC. 855 */ 856 return value + rulep->r_time + offset; 857 } 858 859 /* 860 ** Given a POSIX section 8-style TZ string, fill in the rule tables as 861 ** appropriate. 862 */ 863 864 static int 865 tzparse(const char *name, struct state * const sp, const int lastditch) 866 { 867 const char * stdname; 868 const char * dstname; 869 size_t stdlen; 870 size_t dstlen; 871 long stdoffset; 872 long dstoffset; 873 time_t * atp; 874 unsigned char * typep; 875 char * cp; 876 int load_result; 877 878 INITIALIZE(dstname); 879 stdname = name; 880 if (lastditch) { 881 stdlen = strlen(name); /* length of standard zone name */ 882 name += stdlen; 883 if (stdlen >= sizeof sp->chars) 884 stdlen = (sizeof sp->chars) - 1; 885 stdoffset = 0; 886 } else { 887 if (*name == '<') { 888 name++; 889 stdname = name; 890 name = getqzname(name, '>'); 891 if (*name != '>') 892 return (-1); 893 stdlen = name - stdname; 894 name++; 895 } else { 896 name = getzname(name); 897 stdlen = name - stdname; 898 } 899 if (*name == '\0') 900 return -1; 901 name = getoffset(name, &stdoffset); 902 if (name == NULL) 903 return -1; 904 } 905 load_result = tzload(TZDEFRULES, sp, FALSE); 906 if (load_result != 0) 907 sp->leapcnt = 0; /* so, we're off a little */ 908 if (*name != '\0') { 909 if (*name == '<') { 910 dstname = ++name; 911 name = getqzname(name, '>'); 912 if (*name != '>') 913 return -1; 914 dstlen = name - dstname; 915 name++; 916 } else { 917 dstname = name; 918 name = getzname(name); 919 dstlen = name - dstname; /* length of DST zone name */ 920 } 921 if (*name != '\0' && *name != ',' && *name != ';') { 922 name = getoffset(name, &dstoffset); 923 if (name == NULL) 924 return -1; 925 } else dstoffset = stdoffset - SECSPERHOUR; 926 if (*name == '\0' && load_result != 0) 927 name = TZDEFRULESTRING; 928 if (*name == ',' || *name == ';') { 929 struct rule start; 930 struct rule end; 931 int year; 932 time_t janfirst; 933 time_t starttime; 934 time_t endtime; 935 936 ++name; 937 if ((name = getrule(name, &start)) == NULL) 938 return -1; 939 if (*name++ != ',') 940 return -1; 941 if ((name = getrule(name, &end)) == NULL) 942 return -1; 943 if (*name != '\0') 944 return -1; 945 sp->typecnt = 2; /* standard time and DST */ 946 /* 947 ** Two transitions per year, from EPOCH_YEAR forward. 948 */ 949 sp->ttis[0].tt_gmtoff = -dstoffset; 950 sp->ttis[0].tt_isdst = 1; 951 sp->ttis[0].tt_abbrind = stdlen + 1; 952 sp->ttis[1].tt_gmtoff = -stdoffset; 953 sp->ttis[1].tt_isdst = 0; 954 sp->ttis[1].tt_abbrind = 0; 955 atp = sp->ats; 956 typep = sp->types; 957 janfirst = 0; 958 sp->timecnt = 0; 959 for (year = EPOCH_YEAR; 960 sp->timecnt + 2 <= TZ_MAX_TIMES; 961 ++year) { 962 time_t newfirst; 963 964 starttime = transtime(janfirst, year, &start, 965 stdoffset); 966 endtime = transtime(janfirst, year, &end, 967 dstoffset); 968 if (starttime > endtime) { 969 *atp++ = endtime; 970 *typep++ = 1; /* DST ends */ 971 *atp++ = starttime; 972 *typep++ = 0; /* DST begins */ 973 } else { 974 *atp++ = starttime; 975 *typep++ = 0; /* DST begins */ 976 *atp++ = endtime; 977 *typep++ = 1; /* DST ends */ 978 } 979 sp->timecnt += 2; 980 newfirst = janfirst; 981 newfirst += year_lengths[isleap(year)] * 982 SECSPERDAY; 983 if (newfirst <= janfirst) 984 break; 985 janfirst = newfirst; 986 } 987 } else { 988 long theirstdoffset; 989 long theirdstoffset; 990 long theiroffset; 991 int isdst; 992 int i; 993 int j; 994 995 if (*name != '\0') 996 return -1; 997 /* 998 ** Initial values of theirstdoffset and theirdstoffset. 999 */ 1000 theirstdoffset = 0; 1001 for (i = 0; i < sp->timecnt; ++i) { 1002 j = sp->types[i]; 1003 if (!sp->ttis[j].tt_isdst) { 1004 theirstdoffset = 1005 -sp->ttis[j].tt_gmtoff; 1006 break; 1007 } 1008 } 1009 theirdstoffset = 0; 1010 for (i = 0; i < sp->timecnt; ++i) { 1011 j = sp->types[i]; 1012 if (sp->ttis[j].tt_isdst) { 1013 theirdstoffset = 1014 -sp->ttis[j].tt_gmtoff; 1015 break; 1016 } 1017 } 1018 /* 1019 ** Initially we're assumed to be in standard time. 1020 */ 1021 isdst = FALSE; 1022 theiroffset = theirstdoffset; 1023 /* 1024 ** Now juggle transition times and types 1025 ** tracking offsets as you do. 1026 */ 1027 for (i = 0; i < sp->timecnt; ++i) { 1028 j = sp->types[i]; 1029 sp->types[i] = sp->ttis[j].tt_isdst; 1030 if (sp->ttis[j].tt_ttisgmt) { 1031 /* No adjustment to transition time */ 1032 } else { 1033 /* 1034 ** If summer time is in effect, and the 1035 ** transition time was not specified as 1036 ** standard time, add the summer time 1037 ** offset to the transition time; 1038 ** otherwise, add the standard time 1039 ** offset to the transition time. 1040 */ 1041 /* 1042 ** Transitions from DST to DDST 1043 ** will effectively disappear since 1044 ** POSIX provides for only one DST 1045 ** offset. 1046 */ 1047 if (isdst && !sp->ttis[j].tt_ttisstd) { 1048 sp->ats[i] += dstoffset - 1049 theirdstoffset; 1050 } else { 1051 sp->ats[i] += stdoffset - 1052 theirstdoffset; 1053 } 1054 } 1055 theiroffset = -sp->ttis[j].tt_gmtoff; 1056 if (sp->ttis[j].tt_isdst) 1057 theirdstoffset = theiroffset; 1058 else theirstdoffset = theiroffset; 1059 } 1060 /* 1061 ** Finally, fill in ttis. 1062 ** ttisstd and ttisgmt need not be handled. 1063 */ 1064 sp->ttis[0].tt_gmtoff = -stdoffset; 1065 sp->ttis[0].tt_isdst = FALSE; 1066 sp->ttis[0].tt_abbrind = 0; 1067 sp->ttis[1].tt_gmtoff = -dstoffset; 1068 sp->ttis[1].tt_isdst = TRUE; 1069 sp->ttis[1].tt_abbrind = stdlen + 1; 1070 sp->typecnt = 2; 1071 } 1072 } else { 1073 dstlen = 0; 1074 sp->typecnt = 1; /* only standard time */ 1075 sp->timecnt = 0; 1076 sp->ttis[0].tt_gmtoff = -stdoffset; 1077 sp->ttis[0].tt_isdst = 0; 1078 sp->ttis[0].tt_abbrind = 0; 1079 } 1080 sp->charcnt = stdlen + 1; 1081 if (dstlen != 0) 1082 sp->charcnt += dstlen + 1; 1083 if ((size_t) sp->charcnt > sizeof sp->chars) 1084 return -1; 1085 cp = sp->chars; 1086 strncpy(cp, stdname, stdlen); 1087 cp += stdlen; 1088 *cp++ = '\0'; 1089 if (dstlen != 0) { 1090 strncpy(cp, dstname, dstlen); 1091 *(cp + dstlen) = '\0'; 1092 } 1093 return 0; 1094 } 1095 1096 static void 1097 gmtload(struct state * const sp) 1098 { 1099 if (tzload(gmt, sp, TRUE) != 0) 1100 tzparse(gmt, sp, TRUE); 1101 } 1102 1103 static void 1104 tzsetwall_basic(void) 1105 { 1106 if (lcl_is_set < 0) 1107 return; 1108 lcl_is_set = -1; 1109 1110 if (tzload((char *) NULL, lclptr, TRUE) != 0) 1111 gmtload(lclptr); 1112 settzname(); 1113 } 1114 1115 void 1116 tzsetwall(void) 1117 { 1118 _MUTEX_LOCK(&lcl_mutex); 1119 tzsetwall_basic(); 1120 _MUTEX_UNLOCK(&lcl_mutex); 1121 } 1122 1123 static void 1124 tzset_basic(void) 1125 { 1126 const char * name; 1127 1128 name = getenv("TZ"); 1129 if (name == NULL) { 1130 tzsetwall_basic(); 1131 return; 1132 } 1133 1134 if (lcl_is_set > 0 && strcmp(lcl_TZname, name) == 0) 1135 return; 1136 lcl_is_set = strlen(name) < sizeof lcl_TZname; 1137 if (lcl_is_set) 1138 strcpy(lcl_TZname, name); 1139 1140 if (*name == '\0') { 1141 /* 1142 ** User wants it fast rather than right. 1143 */ 1144 lclptr->leapcnt = 0; /* so, we're off a little */ 1145 lclptr->timecnt = 0; 1146 lclptr->typecnt = 0; 1147 lclptr->ttis[0].tt_isdst = 0; 1148 lclptr->ttis[0].tt_gmtoff = 0; 1149 lclptr->ttis[0].tt_abbrind = 0; 1150 strcpy(lclptr->chars, gmt); 1151 } else if (tzload(name, lclptr, TRUE) != 0) 1152 if (name[0] == ':' || tzparse(name, lclptr, FALSE) != 0) 1153 gmtload(lclptr); 1154 settzname(); 1155 } 1156 1157 void 1158 tzset(void) 1159 { 1160 _MUTEX_LOCK(&lcl_mutex); 1161 tzset_basic(); 1162 _MUTEX_UNLOCK(&lcl_mutex); 1163 } 1164 1165 /* 1166 ** The easy way to behave "as if no library function calls" localtime 1167 ** is to not call it--so we drop its guts into "localsub", which can be 1168 ** freely called. (And no, the PANS doesn't require the above behavior-- 1169 ** but it *is* desirable.) 1170 ** 1171 ** The unused offset argument is for the benefit of mktime variants. 1172 */ 1173 1174 /*ARGSUSED*/ 1175 static struct tm * 1176 localsub(const time_t * const timep, const long offset __unused, 1177 struct tm * const tmp) 1178 { 1179 struct state * sp; 1180 const struct ttinfo * ttisp; 1181 int i; 1182 struct tm * result; 1183 const time_t t = *timep; 1184 1185 sp = lclptr; 1186 1187 if ((sp->goback && t < sp->ats[0]) || 1188 (sp->goahead && t > sp->ats[sp->timecnt - 1])) { 1189 time_t newt = t; 1190 time_t seconds; 1191 time_t tcycles; 1192 int_fast64_t icycles; 1193 1194 if (t < sp->ats[0]) 1195 seconds = sp->ats[0] - t; 1196 else seconds = t - sp->ats[sp->timecnt - 1]; 1197 --seconds; 1198 tcycles = seconds / YEARSPERREPEAT / AVGSECSPERYEAR; 1199 ++tcycles; 1200 icycles = tcycles; 1201 if (tcycles - icycles >= 1 || icycles - tcycles >= 1) 1202 return NULL; 1203 seconds = icycles; 1204 seconds *= YEARSPERREPEAT; 1205 seconds *= AVGSECSPERYEAR; 1206 if (t < sp->ats[0]) 1207 newt += seconds; 1208 else newt -= seconds; 1209 if (newt < sp->ats[0] || 1210 newt > sp->ats[sp->timecnt - 1]) 1211 return NULL; /* "cannot happen" */ 1212 result = localsub(&newt, offset, tmp); 1213 if (result == tmp) { 1214 time_t newy; 1215 1216 newy = tmp->tm_year; 1217 if (t < sp->ats[0]) 1218 newy -= icycles * YEARSPERREPEAT; 1219 else newy += icycles * YEARSPERREPEAT; 1220 tmp->tm_year = newy; 1221 if (tmp->tm_year != newy) 1222 return NULL; 1223 } 1224 return result; 1225 } 1226 if (sp->timecnt == 0 || t < sp->ats[0]) { 1227 i = 0; 1228 while (sp->ttis[i].tt_isdst) 1229 if (++i >= sp->typecnt) { 1230 i = 0; 1231 break; 1232 } 1233 } else { 1234 int lo = 1; 1235 int hi = sp->timecnt; 1236 1237 while (lo < hi) { 1238 int mid = (lo + hi) >> 1; 1239 1240 if (t < sp->ats[mid]) 1241 hi = mid; 1242 else lo = mid + 1; 1243 } 1244 i = (int) sp->types[lo - 1]; 1245 } 1246 ttisp = &sp->ttis[i]; 1247 /* 1248 ** To get (wrong) behavior that's compatible with System V Release 2.0 1249 ** you'd replace the statement below with 1250 ** t += ttisp->tt_gmtoff; 1251 ** timesub(&t, 0L, sp, tmp); 1252 */ 1253 result = timesub(&t, ttisp->tt_gmtoff, sp, tmp); 1254 tmp->tm_isdst = ttisp->tt_isdst; 1255 tzname[tmp->tm_isdst] = &sp->chars[ttisp->tt_abbrind]; 1256 #ifdef TM_ZONE 1257 tmp->TM_ZONE = &sp->chars[ttisp->tt_abbrind]; 1258 #endif /* defined TM_ZONE */ 1259 return result; 1260 } 1261 1262 struct tm * 1263 localtime_r(const time_t * const timep, struct tm *p_tm) 1264 { 1265 _MUTEX_LOCK(&lcl_mutex); 1266 tzset_basic(); 1267 localsub(timep, 0L, p_tm); 1268 _MUTEX_UNLOCK(&lcl_mutex); 1269 return(p_tm); 1270 } 1271 1272 struct tm * 1273 localtime(const time_t * const timep) 1274 { 1275 static pthread_mutex_t localtime_mutex = PTHREAD_MUTEX_INITIALIZER; 1276 static pthread_key_t localtime_key = -1; 1277 struct tm *p_tm; 1278 1279 if (__isthreaded != 0) { 1280 _pthread_mutex_lock(&localtime_mutex); 1281 if (localtime_key < 0) { 1282 if (_pthread_key_create(&localtime_key, free) < 0) { 1283 _pthread_mutex_unlock(&localtime_mutex); 1284 return(NULL); 1285 } 1286 } 1287 _pthread_mutex_unlock(&localtime_mutex); 1288 p_tm = _pthread_getspecific(localtime_key); 1289 if (p_tm == NULL) { 1290 if ((p_tm = (struct tm *)malloc(sizeof(struct tm))) 1291 == NULL) 1292 return(NULL); 1293 _pthread_setspecific(localtime_key, p_tm); 1294 } 1295 _pthread_mutex_lock(&lcl_mutex); 1296 tzset_basic(); 1297 localsub(timep, 0L, p_tm); 1298 _pthread_mutex_unlock(&lcl_mutex); 1299 return(p_tm); 1300 } else { 1301 tzset_basic(); 1302 localsub(timep, 0L, &tm); 1303 return(&tm); 1304 } 1305 } 1306 1307 /* 1308 ** gmtsub is to gmtime as localsub is to localtime. 1309 */ 1310 1311 static struct tm * 1312 gmtsub(const time_t * const timep, const long offset, struct tm * const tmp) 1313 { 1314 struct tm * result; 1315 1316 _MUTEX_LOCK(&gmt_mutex); 1317 if (!gmt_is_set) { 1318 gmt_is_set = TRUE; 1319 gmtload(gmtptr); 1320 } 1321 _MUTEX_UNLOCK(&gmt_mutex); 1322 result = timesub(timep, offset, gmtptr, tmp); 1323 #ifdef TM_ZONE 1324 /* 1325 ** Could get fancy here and deliver something such as 1326 ** "UTC+xxxx" or "UTC-xxxx" if offset is non-zero, 1327 ** but this is no time for a treasure hunt. 1328 */ 1329 if (offset != 0) 1330 tmp->TM_ZONE = wildabbr; 1331 else 1332 tmp->TM_ZONE = gmtptr->chars; 1333 #endif /* defined TM_ZONE */ 1334 return result; 1335 } 1336 1337 struct tm * 1338 gmtime(const time_t * const timep) 1339 { 1340 static pthread_mutex_t gmtime_mutex = PTHREAD_MUTEX_INITIALIZER; 1341 static pthread_key_t gmtime_key = -1; 1342 struct tm *p_tm; 1343 1344 if (__isthreaded != 0) { 1345 _pthread_mutex_lock(&gmtime_mutex); 1346 if (gmtime_key < 0) { 1347 if (_pthread_key_create(&gmtime_key, free) < 0) { 1348 _pthread_mutex_unlock(&gmtime_mutex); 1349 return(NULL); 1350 } 1351 } 1352 _pthread_mutex_unlock(&gmtime_mutex); 1353 /* 1354 * Changed to follow POSIX.1 threads standard, which 1355 * is what BSD currently has. 1356 */ 1357 if ((p_tm = _pthread_getspecific(gmtime_key)) == NULL) { 1358 if ((p_tm = (struct tm *)malloc(sizeof(struct tm))) 1359 == NULL) { 1360 return(NULL); 1361 } 1362 _pthread_setspecific(gmtime_key, p_tm); 1363 } 1364 return gmtsub(timep, 0L, p_tm); 1365 } else { 1366 return gmtsub(timep, 0L, &tm); 1367 } 1368 } 1369 1370 struct tm * 1371 gmtime_r(const time_t * timep, struct tm * tmp) 1372 { 1373 return gmtsub(timep, 0L, tmp); 1374 } 1375 1376 struct tm * 1377 offtime(const time_t * const timep, const long offset) 1378 { 1379 return gmtsub(timep, offset, &tm); 1380 } 1381 1382 /* 1383 ** Return the number of leap years through the end of the given year 1384 ** where, to make the math easy, the answer for year zero is defined as zero. 1385 */ 1386 1387 static int 1388 leaps_thru_end_of(const int y) 1389 { 1390 return (y >= 0) ? (y / 4 - y / 100 + y / 400) : 1391 -(leaps_thru_end_of(-(y + 1)) + 1); 1392 } 1393 1394 static struct tm * 1395 timesub(const time_t * const timep, const long offset, 1396 const struct state * const sp, struct tm * const tmp) 1397 { 1398 const struct lsinfo * lp; 1399 time_t tdays; 1400 int idays; /* unsigned would be so 2003 */ 1401 long rem; 1402 int y; 1403 int yleap; 1404 const int * ip; 1405 long corr; 1406 int hit; 1407 int i; 1408 1409 corr = 0; 1410 hit = 0; 1411 i = sp->leapcnt; 1412 1413 while (--i >= 0) { 1414 lp = &sp->lsis[i]; 1415 if (*timep >= lp->ls_trans) { 1416 if (*timep == lp->ls_trans) { 1417 hit = ((i == 0 && lp->ls_corr > 0) || 1418 lp->ls_corr > sp->lsis[i - 1].ls_corr); 1419 if (hit) 1420 while (i > 0 && 1421 sp->lsis[i].ls_trans == 1422 sp->lsis[i - 1].ls_trans + 1 && 1423 sp->lsis[i].ls_corr == 1424 sp->lsis[i - 1].ls_corr + 1) { 1425 ++hit; 1426 --i; 1427 } 1428 } 1429 corr = lp->ls_corr; 1430 break; 1431 } 1432 } 1433 y = EPOCH_YEAR; 1434 tdays = *timep / SECSPERDAY; 1435 rem = *timep - tdays * SECSPERDAY; 1436 while (tdays < 0 || tdays >= year_lengths[isleap(y)]) { 1437 int newy; 1438 time_t tdelta; 1439 int idelta; 1440 int leapdays; 1441 1442 tdelta = tdays / DAYSPERLYEAR; 1443 idelta = tdelta; 1444 if (tdelta - idelta >= 1 || idelta - tdelta >= 1) 1445 return NULL; 1446 if (idelta == 0) 1447 idelta = (tdays < 0) ? -1 : 1; 1448 newy = y; 1449 if (increment_overflow(&newy, idelta)) 1450 return NULL; 1451 leapdays = leaps_thru_end_of(newy - 1) - 1452 leaps_thru_end_of(y - 1); 1453 tdays -= ((time_t) newy - y) * DAYSPERNYEAR; 1454 tdays -= leapdays; 1455 y = newy; 1456 } 1457 { 1458 long seconds; 1459 1460 seconds = tdays * SECSPERDAY + 0.5; 1461 tdays = seconds / SECSPERDAY; 1462 rem += seconds - tdays * SECSPERDAY; 1463 } 1464 /* 1465 ** Given the range, we can now fearlessly cast... 1466 */ 1467 idays = tdays; 1468 rem += offset - corr; 1469 while (rem < 0) { 1470 rem += SECSPERDAY; 1471 --idays; 1472 } 1473 while (rem >= SECSPERDAY) { 1474 rem -= SECSPERDAY; 1475 ++idays; 1476 } 1477 while (idays < 0) { 1478 if (increment_overflow(&y, -1)) 1479 return NULL; 1480 idays += year_lengths[isleap(y)]; 1481 } 1482 while (idays >= year_lengths[isleap(y)]) { 1483 idays -= year_lengths[isleap(y)]; 1484 if (increment_overflow(&y, 1)) 1485 return NULL; 1486 } 1487 tmp->tm_year = y; 1488 if (increment_overflow(&tmp->tm_year, -TM_YEAR_BASE)) 1489 return NULL; 1490 tmp->tm_yday = idays; 1491 /* 1492 ** The "extra" mods below avoid overflow problems. 1493 */ 1494 tmp->tm_wday = EPOCH_WDAY + 1495 ((y - EPOCH_YEAR) % DAYSPERWEEK) * 1496 (DAYSPERNYEAR % DAYSPERWEEK) + 1497 leaps_thru_end_of(y - 1) - 1498 leaps_thru_end_of(EPOCH_YEAR - 1) + 1499 idays; 1500 tmp->tm_wday %= DAYSPERWEEK; 1501 if (tmp->tm_wday < 0) 1502 tmp->tm_wday += DAYSPERWEEK; 1503 tmp->tm_hour = (int) (rem / SECSPERHOUR); 1504 rem %= SECSPERHOUR; 1505 tmp->tm_min = (int) (rem / SECSPERMIN); 1506 /* 1507 ** A positive leap second requires a special 1508 ** representation. This uses "... ??:59:60" et seq. 1509 */ 1510 tmp->tm_sec = (int) (rem % SECSPERMIN) + hit; 1511 ip = mon_lengths[isleap(y)]; 1512 for (tmp->tm_mon = 0; idays >= ip[tmp->tm_mon]; ++(tmp->tm_mon)) 1513 idays -= ip[tmp->tm_mon]; 1514 tmp->tm_mday = (int) (idays + 1); 1515 tmp->tm_isdst = 0; 1516 #ifdef TM_GMTOFF 1517 tmp->TM_GMTOFF = offset; 1518 #endif /* defined TM_GMTOFF */ 1519 return tmp; 1520 } 1521 1522 char * 1523 ctime(const time_t * const timep) 1524 { 1525 /* 1526 ** Section 4.12.3.2 of X3.159-1989 requires that 1527 ** The ctime function converts the calendar time pointed to by timer 1528 ** to local time in the form of a string. It is equivalent to 1529 ** asctime(localtime(timer)) 1530 */ 1531 return asctime(localtime(timep)); 1532 } 1533 1534 char * 1535 ctime_r(const time_t * const timep, char *buf) 1536 { 1537 struct tm mytm; 1538 return asctime_r(localtime_r(timep, &mytm), buf); 1539 } 1540 1541 /* 1542 ** Adapted from code provided by Robert Elz, who writes: 1543 ** The "best" way to do mktime I think is based on an idea of Bob 1544 ** Kridle's (so its said...) from a long time ago. 1545 ** It does a binary search of the time_t space. Since time_t's are 1546 ** just 32 bits, its a max of 32 iterations (even at 64 bits it 1547 ** would still be very reasonable). 1548 */ 1549 1550 #ifndef WRONG 1551 #define WRONG (-1) 1552 #endif /* !defined WRONG */ 1553 1554 /* 1555 ** Simplified normalize logic courtesy Paul Eggert. 1556 */ 1557 1558 static int 1559 increment_overflow(int *number, int delta) 1560 { 1561 int number0; 1562 1563 number0 = *number; 1564 *number += delta; 1565 return (*number < number0) != (delta < 0); 1566 } 1567 1568 static int 1569 long_increment_overflow(long *number, int delta) 1570 { 1571 long number0; 1572 1573 number0 = *number; 1574 *number += delta; 1575 return (*number < number0) != (delta < 0); 1576 } 1577 1578 static int 1579 normalize_overflow(int * const tensptr, int * const unitsptr, const int base) 1580 { 1581 int tensdelta; 1582 1583 tensdelta = (*unitsptr >= 0) ? 1584 (*unitsptr / base) : 1585 (-1 - (-1 - *unitsptr) / base); 1586 *unitsptr -= tensdelta * base; 1587 return increment_overflow(tensptr, tensdelta); 1588 } 1589 1590 static int 1591 long_normalize_overflow(long * const tensptr, int * const unitsptr, 1592 const int base) 1593 { 1594 int tensdelta; 1595 1596 tensdelta = (*unitsptr >= 0) ? 1597 (*unitsptr / base) : 1598 (-1 - (-1 - *unitsptr) / base); 1599 *unitsptr -= tensdelta * base; 1600 return long_increment_overflow(tensptr, tensdelta); 1601 } 1602 1603 static int 1604 tmcomp(const struct tm * const atmp, const struct tm * const btmp) 1605 { 1606 int result; 1607 1608 if ((result = (atmp->tm_year - btmp->tm_year)) == 0 && 1609 (result = (atmp->tm_mon - btmp->tm_mon)) == 0 && 1610 (result = (atmp->tm_mday - btmp->tm_mday)) == 0 && 1611 (result = (atmp->tm_hour - btmp->tm_hour)) == 0 && 1612 (result = (atmp->tm_min - btmp->tm_min)) == 0) 1613 result = atmp->tm_sec - btmp->tm_sec; 1614 return result; 1615 } 1616 1617 static time_t 1618 time2sub(struct tm * const tmp, 1619 struct tm * (* const funcp)(const time_t *, long, struct tm *), 1620 const long offset, int * const okayp, const int do_norm_secs) 1621 { 1622 const struct state * sp; 1623 int dir; 1624 int i, j; 1625 int saved_seconds; 1626 long li; 1627 time_t lo; 1628 time_t hi; 1629 long y; 1630 time_t newt; 1631 time_t t; 1632 struct tm yourtm, mytm; 1633 1634 *okayp = FALSE; 1635 yourtm = *tmp; 1636 if (do_norm_secs) { 1637 if (normalize_overflow(&yourtm.tm_min, &yourtm.tm_sec, 1638 SECSPERMIN)) 1639 return WRONG; 1640 } 1641 if (normalize_overflow(&yourtm.tm_hour, &yourtm.tm_min, MINSPERHOUR)) 1642 return WRONG; 1643 if (normalize_overflow(&yourtm.tm_mday, &yourtm.tm_hour, HOURSPERDAY)) 1644 return WRONG; 1645 y = yourtm.tm_year; 1646 if (long_normalize_overflow(&y, &yourtm.tm_mon, MONSPERYEAR)) 1647 return WRONG; 1648 /* 1649 ** Turn y into an actual year number for now. 1650 ** It is converted back to an offset from TM_YEAR_BASE later. 1651 */ 1652 if (long_increment_overflow(&y, TM_YEAR_BASE)) 1653 return WRONG; 1654 while (yourtm.tm_mday <= 0) { 1655 if (long_increment_overflow(&y, -1)) 1656 return WRONG; 1657 li = y + (1 < yourtm.tm_mon); 1658 yourtm.tm_mday += year_lengths[isleap(li)]; 1659 } 1660 while (yourtm.tm_mday > DAYSPERLYEAR) { 1661 li = y + (1 < yourtm.tm_mon); 1662 yourtm.tm_mday -= year_lengths[isleap(li)]; 1663 if (long_increment_overflow(&y, 1)) 1664 return WRONG; 1665 } 1666 for ( ; ; ) { 1667 i = mon_lengths[isleap(y)][yourtm.tm_mon]; 1668 if (yourtm.tm_mday <= i) 1669 break; 1670 yourtm.tm_mday -= i; 1671 if (++yourtm.tm_mon >= MONSPERYEAR) { 1672 yourtm.tm_mon = 0; 1673 if (long_increment_overflow(&y, 1)) 1674 return WRONG; 1675 } 1676 } 1677 if (long_increment_overflow(&y, -TM_YEAR_BASE)) 1678 return WRONG; 1679 yourtm.tm_year = y; 1680 if (yourtm.tm_year != y) 1681 return WRONG; 1682 if (yourtm.tm_sec >= 0 && yourtm.tm_sec < SECSPERMIN) 1683 saved_seconds = 0; 1684 else if (y + TM_YEAR_BASE < EPOCH_YEAR) { 1685 /* 1686 ** We can't set tm_sec to 0, because that might push the 1687 ** time below the minimum representable time. 1688 ** Set tm_sec to 59 instead. 1689 ** This assumes that the minimum representable time is 1690 ** not in the same minute that a leap second was deleted from, 1691 ** which is a safer assumption than using 58 would be. 1692 */ 1693 if (increment_overflow(&yourtm.tm_sec, 1 - SECSPERMIN)) 1694 return WRONG; 1695 saved_seconds = yourtm.tm_sec; 1696 yourtm.tm_sec = SECSPERMIN - 1; 1697 } else { 1698 saved_seconds = yourtm.tm_sec; 1699 yourtm.tm_sec = 0; 1700 } 1701 /* 1702 ** Do a binary search (this works whatever time_t's type is). 1703 */ 1704 if (!TYPE_SIGNED(time_t)) { 1705 lo = 0; 1706 hi = lo - 1; 1707 } else if (!TYPE_INTEGRAL(time_t)) { 1708 if (sizeof(time_t) > sizeof(float)) 1709 hi = (time_t) DBL_MAX; 1710 else hi = (time_t) FLT_MAX; 1711 lo = -hi; 1712 } else { 1713 lo = 1; 1714 for (i = 0; i < (int) TYPE_BIT(time_t) - 1; ++i) 1715 lo *= 2; 1716 hi = -(lo + 1); 1717 } 1718 for ( ; ; ) { 1719 t = lo / 2 + hi / 2; 1720 if (t < lo) 1721 t = lo; 1722 else if (t > hi) 1723 t = hi; 1724 if ((*funcp)(&t, offset, &mytm) == NULL) { 1725 /* 1726 ** Assume that t is too extreme to be represented in 1727 ** a struct tm; arrange things so that it is less 1728 ** extreme on the next pass. 1729 */ 1730 dir = (t > 0) ? 1 : -1; 1731 } else dir = tmcomp(&mytm, &yourtm); 1732 if (dir != 0) { 1733 if (t == lo) { 1734 ++t; 1735 if (t <= lo) 1736 return WRONG; 1737 ++lo; 1738 } else if (t == hi) { 1739 --t; 1740 if (t >= hi) 1741 return WRONG; 1742 --hi; 1743 } 1744 if (lo > hi) 1745 return WRONG; 1746 if (dir > 0) 1747 hi = t; 1748 else lo = t; 1749 continue; 1750 } 1751 if (yourtm.tm_isdst < 0 || mytm.tm_isdst == yourtm.tm_isdst) 1752 break; 1753 /* 1754 ** Right time, wrong type. 1755 ** Hunt for right time, right type. 1756 ** It's okay to guess wrong since the guess 1757 ** gets checked. 1758 */ 1759 sp = (const struct state *) 1760 ((funcp == localsub) ? lclptr : gmtptr); 1761 1762 for (i = sp->typecnt - 1; i >= 0; --i) { 1763 if (sp->ttis[i].tt_isdst != yourtm.tm_isdst) 1764 continue; 1765 for (j = sp->typecnt - 1; j >= 0; --j) { 1766 if (sp->ttis[j].tt_isdst == yourtm.tm_isdst) 1767 continue; 1768 newt = t + sp->ttis[j].tt_gmtoff - 1769 sp->ttis[i].tt_gmtoff; 1770 if ((*funcp)(&newt, offset, &mytm) == NULL) 1771 continue; 1772 if (tmcomp(&mytm, &yourtm) != 0) 1773 continue; 1774 if (mytm.tm_isdst != yourtm.tm_isdst) 1775 continue; 1776 /* 1777 ** We have a match. 1778 */ 1779 t = newt; 1780 goto label; 1781 } 1782 } 1783 return WRONG; 1784 } 1785 label: 1786 newt = t + saved_seconds; 1787 if ((newt < t) != (saved_seconds < 0)) 1788 return WRONG; 1789 t = newt; 1790 if ((*funcp)(&t, offset, tmp)) 1791 *okayp = TRUE; 1792 return t; 1793 } 1794 1795 static time_t 1796 time2(struct tm * const tmp, 1797 struct tm * (* const funcp)(const time_t *, long, struct tm *), 1798 const long offset, int * const okayp) 1799 { 1800 time_t t; 1801 1802 /* 1803 ** First try without normalization of seconds 1804 ** (in case tm_sec contains a value associated with a leap second). 1805 ** If that fails, try with normalization of seconds. 1806 */ 1807 t = time2sub(tmp, funcp, offset, okayp, FALSE); 1808 return *okayp ? t : time2sub(tmp, funcp, offset, okayp, TRUE); 1809 } 1810 1811 static time_t 1812 time1(struct tm * const tmp, 1813 struct tm * (* const funcp)(const time_t *, long, struct tm *), 1814 const long offset) 1815 { 1816 time_t t; 1817 const struct state * sp; 1818 int samei, otheri; 1819 int sameind, otherind; 1820 int i; 1821 int nseen; 1822 int seen[TZ_MAX_TYPES]; 1823 int types[TZ_MAX_TYPES]; 1824 int okay; 1825 1826 if (tmp->tm_isdst > 1) 1827 tmp->tm_isdst = 1; 1828 t = time2(tmp, funcp, offset, &okay); 1829 1830 /* 1831 ** PCTS code courtesy Grant Sullivan. 1832 */ 1833 if (okay) 1834 return t; 1835 if (tmp->tm_isdst < 0) 1836 tmp->tm_isdst = 0; /* reset to std and try again */ 1837 1838 /* 1839 ** We're supposed to assume that somebody took a time of one type 1840 ** and did some math on it that yielded a "struct tm" that's bad. 1841 ** We try to divine the type they started from and adjust to the 1842 ** type they need. 1843 */ 1844 sp = (const struct state *) ((funcp == localsub) ? lclptr : gmtptr); 1845 1846 for (i = 0; i < sp->typecnt; ++i) 1847 seen[i] = FALSE; 1848 nseen = 0; 1849 for (i = sp->timecnt - 1; i >= 0; --i) 1850 if (!seen[sp->types[i]]) { 1851 seen[sp->types[i]] = TRUE; 1852 types[nseen++] = sp->types[i]; 1853 } 1854 for (sameind = 0; sameind < nseen; ++sameind) { 1855 samei = types[sameind]; 1856 if (sp->ttis[samei].tt_isdst != tmp->tm_isdst) 1857 continue; 1858 for (otherind = 0; otherind < nseen; ++otherind) { 1859 otheri = types[otherind]; 1860 if (sp->ttis[otheri].tt_isdst == tmp->tm_isdst) 1861 continue; 1862 tmp->tm_sec += sp->ttis[otheri].tt_gmtoff - 1863 sp->ttis[samei].tt_gmtoff; 1864 tmp->tm_isdst = !tmp->tm_isdst; 1865 t = time2(tmp, funcp, offset, &okay); 1866 if (okay) 1867 return t; 1868 tmp->tm_sec -= sp->ttis[otheri].tt_gmtoff - 1869 sp->ttis[samei].tt_gmtoff; 1870 tmp->tm_isdst = !tmp->tm_isdst; 1871 } 1872 } 1873 return WRONG; 1874 } 1875 1876 time_t 1877 mktime(struct tm * const tmp) 1878 { 1879 time_t mktime_return_value; 1880 _MUTEX_LOCK(&lcl_mutex); 1881 tzset_basic(); 1882 mktime_return_value = time1(tmp, localsub, 0L); 1883 _MUTEX_UNLOCK(&lcl_mutex); 1884 return(mktime_return_value); 1885 } 1886 1887 time_t 1888 timelocal(struct tm * const tmp) 1889 { 1890 tmp->tm_isdst = -1; /* in case it wasn't initialized */ 1891 return mktime(tmp); 1892 } 1893 1894 time_t 1895 timegm(struct tm * const tmp) 1896 { 1897 tmp->tm_isdst = 0; 1898 return time1(tmp, gmtsub, 0L); 1899 } 1900 1901 time_t 1902 timeoff(struct tm * const tmp, const long offset) 1903 { 1904 tmp->tm_isdst = 0; 1905 return time1(tmp, gmtsub, offset); 1906 } 1907 1908 #ifdef CMUCS 1909 1910 /* 1911 ** The following is supplied for compatibility with 1912 ** previous versions of the CMUCS runtime library. 1913 */ 1914 1915 long 1916 gtime(struct tm * const tmp) 1917 { 1918 const time_t t = mktime(tmp); 1919 1920 if (t == WRONG) 1921 return -1; 1922 return t; 1923 } 1924 1925 #endif /* defined CMUCS */ 1926 1927 /* 1928 ** XXX--is the below the right way to conditionalize?? 1929 */ 1930 1931 /* 1932 ** IEEE Std 1003.1-1988 (POSIX) legislates that 536457599 1933 ** shall correspond to "Wed Dec 31 23:59:59 UTC 1986", which 1934 ** is not the case if we are accounting for leap seconds. 1935 ** So, we provide the following conversion routines for use 1936 ** when exchanging timestamps with POSIX conforming systems. 1937 */ 1938 1939 static long 1940 leapcorr(time_t *timep) 1941 { 1942 struct state * sp; 1943 struct lsinfo * lp; 1944 int i; 1945 1946 sp = lclptr; 1947 i = sp->leapcnt; 1948 while (--i >= 0) { 1949 lp = &sp->lsis[i]; 1950 if (*timep >= lp->ls_trans) 1951 return lp->ls_corr; 1952 } 1953 return 0; 1954 } 1955 1956 time_t 1957 time2posix(time_t t) 1958 { 1959 tzset(); 1960 return t - leapcorr(&t); 1961 } 1962 1963 time_t 1964 posix2time(time_t t) 1965 { 1966 time_t x; 1967 time_t y; 1968 1969 tzset(); 1970 /* 1971 ** For a positive leap second hit, the result 1972 ** is not unique. For a negative leap second 1973 ** hit, the corresponding time doesn't exist, 1974 ** so we return an adjacent second. 1975 */ 1976 x = t + leapcorr(&t); 1977 y = x - leapcorr(&x); 1978 if (y < t) { 1979 do { 1980 x++; 1981 y = x - leapcorr(&x); 1982 } while (y < t); 1983 if (t != y) 1984 return x - 1; 1985 } else if (y > t) { 1986 do { 1987 --x; 1988 y = x - leapcorr(&x); 1989 } while (y > t); 1990 if (t != y) 1991 return x + 1; 1992 } 1993 return x; 1994 } 1995