1 /* $OpenBSD: localtime.c,v 1.65 2022/10/03 15:34:39 millert Exp $ */ 2 /* 3 ** This file is in the public domain, so clarified as of 4 ** 1996-06-05 by Arthur David Olson. 5 */ 6 7 /* 8 ** Leap second handling from Bradley White. 9 ** POSIX-style TZ environment variable handling from Guy Harris. 10 */ 11 12 #include <ctype.h> 13 #include <errno.h> 14 #include <fcntl.h> 15 #include <stdint.h> 16 #include <stdlib.h> 17 #include <string.h> 18 #include <unistd.h> 19 20 #include "private.h" 21 #include "tzfile.h" 22 #include "thread_private.h" 23 24 #ifndef TZ_ABBR_MAX_LEN 25 #define TZ_ABBR_MAX_LEN 16 26 #endif /* !defined TZ_ABBR_MAX_LEN */ 27 28 #ifndef TZ_ABBR_CHAR_SET 29 #define TZ_ABBR_CHAR_SET \ 30 "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789 :+-._" 31 #endif /* !defined TZ_ABBR_CHAR_SET */ 32 33 #ifndef TZ_ABBR_ERR_CHAR 34 #define TZ_ABBR_ERR_CHAR '_' 35 #endif /* !defined TZ_ABBR_ERR_CHAR */ 36 37 #ifndef WILDABBR 38 /* 39 ** Someone might make incorrect use of a time zone abbreviation: 40 ** 1. They might reference tzname[0] before calling tzset (explicitly 41 ** or implicitly). 42 ** 2. They might reference tzname[1] before calling tzset (explicitly 43 ** or implicitly). 44 ** 3. They might reference tzname[1] after setting to a time zone 45 ** in which Daylight Saving Time is never observed. 46 ** 4. They might reference tzname[0] after setting to a time zone 47 ** in which Standard Time is never observed. 48 ** 5. They might reference tm.tm_zone after calling offtime. 49 ** What's best to do in the above cases is open to debate; 50 ** for now, we just set things up so that in any of the five cases 51 ** WILDABBR is used. Another possibility: initialize tzname[0] to the 52 ** string "tzname[0] used before set", and similarly for the other cases. 53 ** And another: initialize tzname[0] to "ERA", with an explanation in the 54 ** manual page of what this "time zone abbreviation" means (doing this so 55 ** that tzname[0] has the "normal" length of three characters). 56 */ 57 #define WILDABBR " " 58 #endif /* !defined WILDABBR */ 59 60 static char wildabbr[] = WILDABBR; 61 62 static const char gmt[] = "GMT"; 63 64 /* 65 ** The DST rules to use if TZ has no rules and we can't load TZDEFRULES. 66 ** We default to US rules as of 1999-08-17. 67 ** POSIX 1003.1 section 8.1.1 says that the default DST rules are 68 ** implementation dependent; for historical reasons, US rules are a 69 ** common default. 70 */ 71 #ifndef TZDEFRULESTRING 72 #define TZDEFRULESTRING ",M4.1.0,M10.5.0" 73 #endif /* !defined TZDEFDST */ 74 75 struct ttinfo { /* time type information */ 76 long tt_gmtoff; /* UTC offset in seconds */ 77 int tt_isdst; /* used to set tm_isdst */ 78 int tt_abbrind; /* abbreviation list index */ 79 int tt_ttisstd; /* TRUE if transition is std time */ 80 int tt_ttisgmt; /* TRUE if transition is UTC */ 81 }; 82 83 struct lsinfo { /* leap second information */ 84 time_t ls_trans; /* transition time */ 85 long ls_corr; /* correction to apply */ 86 }; 87 88 #define BIGGEST(a, b) (((a) > (b)) ? (a) : (b)) 89 90 #ifdef TZNAME_MAX 91 #define MY_TZNAME_MAX TZNAME_MAX 92 #endif /* defined TZNAME_MAX */ 93 #ifndef TZNAME_MAX 94 #define MY_TZNAME_MAX 255 95 #endif /* !defined TZNAME_MAX */ 96 97 struct state { 98 int leapcnt; 99 int timecnt; 100 int typecnt; 101 int charcnt; 102 int goback; 103 int goahead; 104 time_t ats[TZ_MAX_TIMES]; 105 unsigned char types[TZ_MAX_TIMES]; 106 struct ttinfo ttis[TZ_MAX_TYPES]; 107 char chars[BIGGEST(BIGGEST(TZ_MAX_CHARS + 1, sizeof gmt), 108 (2 * (MY_TZNAME_MAX + 1)))]; 109 struct lsinfo lsis[TZ_MAX_LEAPS]; 110 }; 111 112 struct rule { 113 int r_type; /* type of rule--see below */ 114 int r_day; /* day number of rule */ 115 int r_week; /* week number of rule */ 116 int r_mon; /* month number of rule */ 117 long r_time; /* transition time of rule */ 118 }; 119 120 #define JULIAN_DAY 0 /* Jn - Julian day */ 121 #define DAY_OF_YEAR 1 /* n - day of year */ 122 #define MONTH_NTH_DAY_OF_WEEK 2 /* Mm.n.d - month, week, day of week */ 123 124 /* 125 ** Prototypes for static functions. 126 */ 127 128 static long detzcode(const char * codep); 129 static time_t detzcode64(const char * codep); 130 static int differ_by_repeat(time_t t1, time_t t0); 131 static const char * getzname(const char * strp); 132 static const char * getqzname(const char * strp, const int delim); 133 static const char * getnum(const char * strp, int * nump, int min, 134 int max); 135 static const char * getsecs(const char * strp, long * secsp); 136 static const char * getoffset(const char * strp, long * offsetp); 137 static const char * getrule(const char * strp, struct rule * rulep); 138 static void gmtload(struct state * sp); 139 static struct tm * gmtsub(const time_t * timep, long offset, 140 struct tm * tmp); 141 static struct tm * localsub(const time_t * timep, long offset, 142 struct tm * tmp); 143 static int increment_overflow(int * number, int delta); 144 static int leaps_thru_end_of(int y); 145 static int long_increment_overflow(long * number, int delta); 146 static int long_normalize_overflow(long * tensptr, 147 int * unitsptr, int base); 148 static int normalize_overflow(int * tensptr, int * unitsptr, 149 int base); 150 static void settzname(void); 151 static time_t time1(struct tm * tmp, 152 struct tm * (*funcp)(const time_t *, 153 long, struct tm *), 154 long offset); 155 static time_t time2(struct tm *tmp, 156 struct tm * (*funcp)(const time_t *, 157 long, struct tm*), 158 long offset, int * okayp); 159 static time_t time2sub(struct tm *tmp, 160 struct tm * (*funcp)(const time_t *, 161 long, struct tm*), 162 long offset, int * okayp, int do_norm_secs); 163 static struct tm * timesub(const time_t * timep, long offset, 164 const struct state * sp, struct tm * tmp); 165 static int tmcomp(const struct tm * atmp, 166 const struct tm * btmp); 167 static time_t transtime(time_t janfirst, int year, 168 const struct rule * rulep, long offset); 169 static int typesequiv(const struct state * sp, int a, int b); 170 static int tzload(const char * name, struct state * sp, 171 int doextend); 172 static int tzparse(const char * name, struct state * sp, 173 int lastditch); 174 175 #ifdef STD_INSPIRED 176 struct tm *offtime(const time_t *, long); 177 time_t time2posix(time_t); 178 time_t posix2time(time_t); 179 PROTO_DEPRECATED(offtime); 180 PROTO_DEPRECATED(time2posix); 181 PROTO_DEPRECATED(posix2time); 182 #endif 183 184 static struct state * lclptr; 185 static struct state * gmtptr; 186 187 188 #ifndef TZ_STRLEN_MAX 189 #define TZ_STRLEN_MAX 255 190 #endif /* !defined TZ_STRLEN_MAX */ 191 192 static char lcl_TZname[TZ_STRLEN_MAX + 1]; 193 static int lcl_is_set; 194 static int gmt_is_set; 195 _THREAD_PRIVATE_MUTEX(lcl); 196 _THREAD_PRIVATE_MUTEX(gmt); 197 198 char * tzname[2] = { 199 wildabbr, 200 wildabbr 201 }; 202 #if 0 203 DEF_WEAK(tzname); 204 #endif 205 206 /* 207 ** Section 4.12.3 of X3.159-1989 requires that 208 ** Except for the strftime function, these functions [asctime, 209 ** ctime, gmtime, localtime] return values in one of two static 210 ** objects: a broken-down time structure and an array of char. 211 ** Thanks to Paul Eggert for noting this. 212 */ 213 214 static struct tm tm; 215 216 long timezone = 0; 217 int daylight = 0; 218 219 static long 220 detzcode(const char *codep) 221 { 222 long result; 223 int i; 224 225 result = (codep[0] & 0x80) ? ~0L : 0; 226 for (i = 0; i < 4; ++i) 227 result = (result << 8) | (codep[i] & 0xff); 228 return result; 229 } 230 231 static time_t 232 detzcode64(const char *codep) 233 { 234 time_t result; 235 int i; 236 237 result = (codep[0] & 0x80) ? (~(int_fast64_t) 0) : 0; 238 for (i = 0; i < 8; ++i) 239 result = result * 256 + (codep[i] & 0xff); 240 return result; 241 } 242 243 static void 244 settzname(void) 245 { 246 struct state * const sp = lclptr; 247 int i; 248 249 tzname[0] = wildabbr; 250 tzname[1] = wildabbr; 251 daylight = 0; 252 timezone = 0; 253 if (sp == NULL) { 254 tzname[0] = tzname[1] = (char *)gmt; 255 return; 256 } 257 /* 258 ** And to get the latest zone names into tzname. . . 259 */ 260 for (i = 0; i < sp->timecnt; ++i) { 261 const struct ttinfo *ttisp = &sp->ttis[sp->types[i]]; 262 263 tzname[ttisp->tt_isdst] = &sp->chars[ttisp->tt_abbrind]; 264 if (ttisp->tt_isdst) 265 daylight = 1; 266 if (!ttisp->tt_isdst) 267 timezone = -(ttisp->tt_gmtoff); 268 } 269 /* 270 ** Finally, scrub the abbreviations. 271 ** First, replace bogus characters. 272 */ 273 for (i = 0; i < sp->charcnt; ++i) { 274 if (strchr(TZ_ABBR_CHAR_SET, sp->chars[i]) == NULL) 275 sp->chars[i] = TZ_ABBR_ERR_CHAR; 276 } 277 /* 278 ** Second, truncate long abbreviations. 279 */ 280 for (i = 0; i < sp->typecnt; ++i) { 281 const struct ttinfo *ttisp = &sp->ttis[i]; 282 char *cp = &sp->chars[ttisp->tt_abbrind]; 283 284 if (strlen(cp) > TZ_ABBR_MAX_LEN && 285 strcmp(cp, GRANDPARENTED) != 0) 286 *(cp + TZ_ABBR_MAX_LEN) = '\0'; 287 } 288 } 289 290 static int 291 differ_by_repeat(time_t t1, time_t t0) 292 { 293 if (TYPE_BIT(time_t) - 1 < SECSPERREPEAT_BITS) 294 return 0; 295 return (int64_t)t1 - t0 == SECSPERREPEAT; 296 } 297 298 static int 299 tzpath_ok(const char *name) 300 { 301 /* Reject absolute paths that don't start with TZDIR. */ 302 if (name[0] == '/' && (strncmp(name, TZDIR, sizeof(TZDIR) - 1) != 0 || 303 name[sizeof(TZDIR) - 1] != '/')) 304 return 0; 305 306 /* Reject paths that contain "../". */ 307 if (strstr(name, "../") != NULL) 308 return 0; 309 310 return 1; 311 } 312 313 static int 314 open_tzfile(const char *name) 315 { 316 char fullname[PATH_MAX]; 317 int i; 318 319 if (name != NULL) { 320 /* 321 * POSIX section 8 says that names starting with a ':' are 322 * "implementation-defined". We treat them as timezone paths. 323 */ 324 if (name[0] == ':') 325 name++; 326 327 /* 328 * Ignore absolute paths that don't start with TZDIR 329 * or that contain "../". 330 */ 331 if (!tzpath_ok(name)) 332 name = NULL; 333 } 334 335 if (name == NULL) { 336 name = TZDEFAULT; 337 } else if (name[0] != '/') { 338 /* Time zone data path is relative to TZDIR. */ 339 i = snprintf(fullname, sizeof(fullname), "%s/%s", TZDIR, name); 340 if (i < 0 || i >= sizeof(fullname)) { 341 errno = ENAMETOOLONG; 342 return -1; 343 } 344 name = fullname; 345 } 346 347 return open(name, O_RDONLY); 348 } 349 350 static int 351 tzload(const char *name, struct state *sp, int doextend) 352 { 353 const char * p; 354 int i; 355 int fid; 356 int stored; 357 int nread; 358 typedef union { 359 struct tzhead tzhead; 360 char buf[2 * sizeof(struct tzhead) + 361 2 * sizeof *sp + 362 4 * TZ_MAX_TIMES]; 363 } u_t; 364 u_t * up; 365 366 up = calloc(1, sizeof *up); 367 if (up == NULL) 368 return -1; 369 370 sp->goback = sp->goahead = FALSE; 371 372 if ((fid = open_tzfile(name)) == -1) { 373 /* Could be a POSIX section 8-style TZ string. */ 374 goto oops; 375 } 376 377 nread = read(fid, up->buf, sizeof up->buf); 378 if (close(fid) == -1 || nread <= 0) 379 goto oops; 380 for (stored = 4; stored <= 8; stored *= 2) { 381 int ttisstdcnt; 382 int ttisgmtcnt; 383 384 ttisstdcnt = (int) detzcode(up->tzhead.tzh_ttisstdcnt); 385 ttisgmtcnt = (int) detzcode(up->tzhead.tzh_ttisgmtcnt); 386 sp->leapcnt = (int) detzcode(up->tzhead.tzh_leapcnt); 387 sp->timecnt = (int) detzcode(up->tzhead.tzh_timecnt); 388 sp->typecnt = (int) detzcode(up->tzhead.tzh_typecnt); 389 sp->charcnt = (int) detzcode(up->tzhead.tzh_charcnt); 390 p = up->tzhead.tzh_charcnt + sizeof up->tzhead.tzh_charcnt; 391 if (sp->leapcnt < 0 || sp->leapcnt > TZ_MAX_LEAPS || 392 sp->typecnt <= 0 || sp->typecnt > TZ_MAX_TYPES || 393 sp->timecnt < 0 || sp->timecnt > TZ_MAX_TIMES || 394 sp->charcnt < 0 || sp->charcnt > TZ_MAX_CHARS || 395 (ttisstdcnt != sp->typecnt && ttisstdcnt != 0) || 396 (ttisgmtcnt != sp->typecnt && ttisgmtcnt != 0)) 397 goto oops; 398 if (nread - (p - up->buf) < 399 sp->timecnt * stored + /* ats */ 400 sp->timecnt + /* types */ 401 sp->typecnt * 6 + /* ttinfos */ 402 sp->charcnt + /* chars */ 403 sp->leapcnt * (stored + 4) + /* lsinfos */ 404 ttisstdcnt + /* ttisstds */ 405 ttisgmtcnt) /* ttisgmts */ 406 goto oops; 407 for (i = 0; i < sp->timecnt; ++i) { 408 sp->ats[i] = (stored == 4) ? 409 detzcode(p) : detzcode64(p); 410 p += stored; 411 } 412 for (i = 0; i < sp->timecnt; ++i) { 413 sp->types[i] = (unsigned char) *p++; 414 if (sp->types[i] >= sp->typecnt) 415 goto oops; 416 } 417 for (i = 0; i < sp->typecnt; ++i) { 418 struct ttinfo * ttisp; 419 420 ttisp = &sp->ttis[i]; 421 ttisp->tt_gmtoff = detzcode(p); 422 p += 4; 423 ttisp->tt_isdst = (unsigned char) *p++; 424 if (ttisp->tt_isdst != 0 && ttisp->tt_isdst != 1) 425 goto oops; 426 ttisp->tt_abbrind = (unsigned char) *p++; 427 if (ttisp->tt_abbrind < 0 || 428 ttisp->tt_abbrind > sp->charcnt) 429 goto oops; 430 } 431 for (i = 0; i < sp->charcnt; ++i) 432 sp->chars[i] = *p++; 433 sp->chars[i] = '\0'; /* ensure '\0' at end */ 434 for (i = 0; i < sp->leapcnt; ++i) { 435 struct lsinfo * lsisp; 436 437 lsisp = &sp->lsis[i]; 438 lsisp->ls_trans = (stored == 4) ? 439 detzcode(p) : detzcode64(p); 440 p += stored; 441 lsisp->ls_corr = detzcode(p); 442 p += 4; 443 } 444 for (i = 0; i < sp->typecnt; ++i) { 445 struct ttinfo * ttisp; 446 447 ttisp = &sp->ttis[i]; 448 if (ttisstdcnt == 0) 449 ttisp->tt_ttisstd = FALSE; 450 else { 451 ttisp->tt_ttisstd = *p++; 452 if (ttisp->tt_ttisstd != TRUE && 453 ttisp->tt_ttisstd != FALSE) 454 goto oops; 455 } 456 } 457 for (i = 0; i < sp->typecnt; ++i) { 458 struct ttinfo * ttisp; 459 460 ttisp = &sp->ttis[i]; 461 if (ttisgmtcnt == 0) 462 ttisp->tt_ttisgmt = FALSE; 463 else { 464 ttisp->tt_ttisgmt = *p++; 465 if (ttisp->tt_ttisgmt != TRUE && 466 ttisp->tt_ttisgmt != FALSE) 467 goto oops; 468 } 469 } 470 /* 471 ** Out-of-sort ats should mean we're running on a 472 ** signed time_t system but using a data file with 473 ** unsigned values (or vice versa). 474 */ 475 for (i = 0; i < sp->timecnt - 2; ++i) 476 if (sp->ats[i] > sp->ats[i + 1]) { 477 ++i; 478 /* 479 ** Ignore the end (easy). 480 */ 481 sp->timecnt = i; 482 break; 483 } 484 /* 485 ** If this is an old file, we're done. 486 */ 487 if (up->tzhead.tzh_version[0] == '\0') 488 break; 489 nread -= p - up->buf; 490 for (i = 0; i < nread; ++i) 491 up->buf[i] = p[i]; 492 /* 493 ** If this is a narrow integer time_t system, we're done. 494 */ 495 if (stored >= sizeof(time_t)) 496 break; 497 } 498 if (doextend && nread > 2 && 499 up->buf[0] == '\n' && up->buf[nread - 1] == '\n' && 500 sp->typecnt + 2 <= TZ_MAX_TYPES) { 501 struct state ts; 502 int result; 503 504 up->buf[nread - 1] = '\0'; 505 result = tzparse(&up->buf[1], &ts, FALSE); 506 if (result == 0 && ts.typecnt == 2 && 507 sp->charcnt + ts.charcnt <= TZ_MAX_CHARS) { 508 for (i = 0; i < 2; ++i) 509 ts.ttis[i].tt_abbrind += 510 sp->charcnt; 511 for (i = 0; i < ts.charcnt; ++i) 512 sp->chars[sp->charcnt++] = 513 ts.chars[i]; 514 i = 0; 515 while (i < ts.timecnt && 516 ts.ats[i] <= 517 sp->ats[sp->timecnt - 1]) 518 ++i; 519 while (i < ts.timecnt && 520 sp->timecnt < TZ_MAX_TIMES) { 521 sp->ats[sp->timecnt] = 522 ts.ats[i]; 523 sp->types[sp->timecnt] = 524 sp->typecnt + 525 ts.types[i]; 526 ++sp->timecnt; 527 ++i; 528 } 529 sp->ttis[sp->typecnt++] = ts.ttis[0]; 530 sp->ttis[sp->typecnt++] = ts.ttis[1]; 531 } 532 } 533 if (sp->timecnt > 1) { 534 for (i = 1; i < sp->timecnt; ++i) { 535 if (typesequiv(sp, sp->types[i], sp->types[0]) && 536 differ_by_repeat(sp->ats[i], sp->ats[0])) { 537 sp->goback = TRUE; 538 break; 539 } 540 } 541 for (i = sp->timecnt - 2; i >= 0; --i) { 542 if (typesequiv(sp, sp->types[sp->timecnt - 1], 543 sp->types[i]) && 544 differ_by_repeat(sp->ats[sp->timecnt - 1], 545 sp->ats[i])) { 546 sp->goahead = TRUE; 547 break; 548 } 549 } 550 } 551 free(up); 552 return 0; 553 oops: 554 free(up); 555 return -1; 556 } 557 558 static int 559 typesequiv(const struct state *sp, int a, int b) 560 { 561 int result; 562 563 if (sp == NULL || 564 a < 0 || a >= sp->typecnt || 565 b < 0 || b >= sp->typecnt) 566 result = FALSE; 567 else { 568 const struct ttinfo * ap = &sp->ttis[a]; 569 const struct ttinfo * bp = &sp->ttis[b]; 570 result = ap->tt_gmtoff == bp->tt_gmtoff && 571 ap->tt_isdst == bp->tt_isdst && 572 ap->tt_ttisstd == bp->tt_ttisstd && 573 ap->tt_ttisgmt == bp->tt_ttisgmt && 574 strcmp(&sp->chars[ap->tt_abbrind], 575 &sp->chars[bp->tt_abbrind]) == 0; 576 } 577 return result; 578 } 579 580 static const int mon_lengths[2][MONSPERYEAR] = { 581 { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }, 582 { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 } 583 }; 584 585 static const int year_lengths[2] = { 586 DAYSPERNYEAR, DAYSPERLYEAR 587 }; 588 589 /* 590 ** Given a pointer into a time zone string, scan until a character that is not 591 ** a valid character in a zone name is found. Return a pointer to that 592 ** character. 593 */ 594 595 static const char * 596 getzname(const char *strp) 597 { 598 char c; 599 600 while ((c = *strp) != '\0' && !isdigit((unsigned char)c) && c != ',' && c != '-' && 601 c != '+') 602 ++strp; 603 return strp; 604 } 605 606 /* 607 ** Given a pointer into an extended time zone string, scan until the ending 608 ** delimiter of the zone name is located. Return a pointer to the delimiter. 609 ** 610 ** As with getzname above, the legal character set is actually quite 611 ** restricted, with other characters producing undefined results. 612 ** We don't do any checking here; checking is done later in common-case code. 613 */ 614 615 static const char * 616 getqzname(const char *strp, const int delim) 617 { 618 int c; 619 620 while ((c = *strp) != '\0' && c != delim) 621 ++strp; 622 return strp; 623 } 624 625 /* 626 ** Given a pointer into a time zone string, extract a number from that string. 627 ** Check that the number is within a specified range; if it is not, return 628 ** NULL. 629 ** Otherwise, return a pointer to the first character not part of the number. 630 */ 631 632 static const char * 633 getnum(const char *strp, int *nump, int min, int max) 634 { 635 char c; 636 int num; 637 638 if (strp == NULL || !isdigit((unsigned char)(c = *strp))) 639 return NULL; 640 num = 0; 641 do { 642 num = num * 10 + (c - '0'); 643 if (num > max) 644 return NULL; /* illegal value */ 645 c = *++strp; 646 } while (isdigit((unsigned char)c)); 647 if (num < min) 648 return NULL; /* illegal value */ 649 *nump = num; 650 return strp; 651 } 652 653 /* 654 ** Given a pointer into a time zone string, extract a number of seconds, 655 ** in hh[:mm[:ss]] form, from the string. 656 ** If any error occurs, return NULL. 657 ** Otherwise, return a pointer to the first character not part of the number 658 ** of seconds. 659 */ 660 661 static const char * 662 getsecs(const char *strp, long *secsp) 663 { 664 int num; 665 666 /* 667 ** `HOURSPERDAY * DAYSPERWEEK - 1' allows quasi-Posix rules like 668 ** "M10.4.6/26", which does not conform to Posix, 669 ** but which specifies the equivalent of 670 ** ``02:00 on the first Sunday on or after 23 Oct''. 671 */ 672 strp = getnum(strp, &num, 0, HOURSPERDAY * DAYSPERWEEK - 1); 673 if (strp == NULL) 674 return NULL; 675 *secsp = num * (long) SECSPERHOUR; 676 if (*strp == ':') { 677 ++strp; 678 strp = getnum(strp, &num, 0, MINSPERHOUR - 1); 679 if (strp == NULL) 680 return NULL; 681 *secsp += num * SECSPERMIN; 682 if (*strp == ':') { 683 ++strp; 684 /* `SECSPERMIN' allows for leap seconds. */ 685 strp = getnum(strp, &num, 0, SECSPERMIN); 686 if (strp == NULL) 687 return NULL; 688 *secsp += num; 689 } 690 } 691 return strp; 692 } 693 694 /* 695 ** Given a pointer into a time zone string, extract an offset, in 696 ** [+-]hh[:mm[:ss]] form, from the string. 697 ** If any error occurs, return NULL. 698 ** Otherwise, return a pointer to the first character not part of the time. 699 */ 700 701 static const char * 702 getoffset(const char *strp, long *offsetp) 703 { 704 int neg = 0; 705 706 if (*strp == '-') { 707 neg = 1; 708 ++strp; 709 } else if (*strp == '+') 710 ++strp; 711 strp = getsecs(strp, offsetp); 712 if (strp == NULL) 713 return NULL; /* illegal time */ 714 if (neg) 715 *offsetp = -*offsetp; 716 return strp; 717 } 718 719 /* 720 ** Given a pointer into a time zone string, extract a rule in the form 721 ** date[/time]. See POSIX section 8 for the format of "date" and "time". 722 ** If a valid rule is not found, return NULL. 723 ** Otherwise, return a pointer to the first character not part of the rule. 724 */ 725 726 static const char * 727 getrule(const char *strp, struct rule *rulep) 728 { 729 if (*strp == 'J') { 730 /* 731 ** Julian day. 732 */ 733 rulep->r_type = JULIAN_DAY; 734 ++strp; 735 strp = getnum(strp, &rulep->r_day, 1, DAYSPERNYEAR); 736 } else if (*strp == 'M') { 737 /* 738 ** Month, week, day. 739 */ 740 rulep->r_type = MONTH_NTH_DAY_OF_WEEK; 741 ++strp; 742 strp = getnum(strp, &rulep->r_mon, 1, MONSPERYEAR); 743 if (strp == NULL) 744 return NULL; 745 if (*strp++ != '.') 746 return NULL; 747 strp = getnum(strp, &rulep->r_week, 1, 5); 748 if (strp == NULL) 749 return NULL; 750 if (*strp++ != '.') 751 return NULL; 752 strp = getnum(strp, &rulep->r_day, 0, DAYSPERWEEK - 1); 753 } else if (isdigit((unsigned char)*strp)) { 754 /* 755 ** Day of year. 756 */ 757 rulep->r_type = DAY_OF_YEAR; 758 strp = getnum(strp, &rulep->r_day, 0, DAYSPERLYEAR - 1); 759 } else 760 return NULL; /* invalid format */ 761 if (strp == NULL) 762 return NULL; 763 if (*strp == '/') { 764 /* 765 ** Time specified. 766 */ 767 ++strp; 768 strp = getsecs(strp, &rulep->r_time); 769 } else 770 rulep->r_time = 2 * SECSPERHOUR; /* default = 2:00:00 */ 771 return strp; 772 } 773 774 /* 775 ** Given the Epoch-relative time of January 1, 00:00:00 UTC, in a year, the 776 ** year, a rule, and the offset from UTC at the time that rule takes effect, 777 ** calculate the Epoch-relative time that rule takes effect. 778 */ 779 780 static time_t 781 transtime(time_t janfirst, int year, const struct rule *rulep, long offset) 782 { 783 int leapyear; 784 time_t value; 785 int i; 786 int d, m1, yy0, yy1, yy2, dow; 787 788 value = 0; 789 leapyear = isleap(year); 790 switch (rulep->r_type) { 791 792 case JULIAN_DAY: 793 /* 794 ** Jn - Julian day, 1 == January 1, 60 == March 1 even in leap 795 ** years. 796 ** In non-leap years, or if the day number is 59 or less, just 797 ** add SECSPERDAY times the day number-1 to the time of 798 ** January 1, midnight, to get the day. 799 */ 800 value = janfirst + (rulep->r_day - 1) * SECSPERDAY; 801 if (leapyear && rulep->r_day >= 60) 802 value += SECSPERDAY; 803 break; 804 805 case DAY_OF_YEAR: 806 /* 807 ** n - day of year. 808 ** Just add SECSPERDAY times the day number to the time of 809 ** January 1, midnight, to get the day. 810 */ 811 value = janfirst + rulep->r_day * SECSPERDAY; 812 break; 813 814 case MONTH_NTH_DAY_OF_WEEK: 815 /* 816 ** Mm.n.d - nth "dth day" of month m. 817 */ 818 value = janfirst; 819 for (i = 0; i < rulep->r_mon - 1; ++i) 820 value += mon_lengths[leapyear][i] * SECSPERDAY; 821 822 /* 823 ** Use Zeller's Congruence to get day-of-week of first day of 824 ** month. 825 */ 826 m1 = (rulep->r_mon + 9) % 12 + 1; 827 yy0 = (rulep->r_mon <= 2) ? (year - 1) : year; 828 yy1 = yy0 / 100; 829 yy2 = yy0 % 100; 830 dow = ((26 * m1 - 2) / 10 + 831 1 + yy2 + yy2 / 4 + yy1 / 4 - 2 * yy1) % 7; 832 if (dow < 0) 833 dow += DAYSPERWEEK; 834 835 /* 836 ** "dow" is the day-of-week of the first day of the month. Get 837 ** the day-of-month (zero-origin) of the first "dow" day of the 838 ** month. 839 */ 840 d = rulep->r_day - dow; 841 if (d < 0) 842 d += DAYSPERWEEK; 843 for (i = 1; i < rulep->r_week; ++i) { 844 if (d + DAYSPERWEEK >= 845 mon_lengths[leapyear][rulep->r_mon - 1]) 846 break; 847 d += DAYSPERWEEK; 848 } 849 850 /* 851 ** "d" is the day-of-month (zero-origin) of the day we want. 852 */ 853 value += d * SECSPERDAY; 854 break; 855 } 856 857 /* 858 ** "value" is the Epoch-relative time of 00:00:00 UTC on the day in 859 ** question. To get the Epoch-relative time of the specified local 860 ** time on that day, add the transition time and the current offset 861 ** from UTC. 862 */ 863 return value + rulep->r_time + offset; 864 } 865 866 /* 867 ** Given a POSIX section 8-style TZ string, fill in the rule tables as 868 ** appropriate. 869 */ 870 871 static int 872 tzparse(const char *name, struct state *sp, int lastditch) 873 { 874 const char * stdname; 875 const char * dstname; 876 size_t stdlen; 877 size_t dstlen; 878 long stdoffset; 879 long dstoffset; 880 time_t * atp; 881 unsigned char * typep; 882 char * cp; 883 int load_result; 884 static struct ttinfo zttinfo; 885 886 dstname = NULL; 887 stdname = name; 888 if (lastditch) { 889 stdlen = strlen(name); /* length of standard zone name */ 890 name += stdlen; 891 if (stdlen >= sizeof sp->chars) 892 stdlen = (sizeof sp->chars) - 1; 893 stdoffset = 0; 894 } else { 895 if (*name == '<') { 896 name++; 897 stdname = name; 898 name = getqzname(name, '>'); 899 if (*name != '>') 900 return (-1); 901 stdlen = name - stdname; 902 name++; 903 } else { 904 name = getzname(name); 905 stdlen = name - stdname; 906 } 907 if (*name == '\0') 908 return -1; 909 name = getoffset(name, &stdoffset); 910 if (name == NULL) 911 return -1; 912 } 913 load_result = tzload(TZDEFRULES, sp, FALSE); 914 if (load_result != 0) 915 sp->leapcnt = 0; /* so, we're off a little */ 916 if (*name != '\0') { 917 if (*name == '<') { 918 dstname = ++name; 919 name = getqzname(name, '>'); 920 if (*name != '>') 921 return -1; 922 dstlen = name - dstname; 923 name++; 924 } else { 925 dstname = name; 926 name = getzname(name); 927 dstlen = name - dstname; /* length of DST zone name */ 928 } 929 if (*name != '\0' && *name != ',' && *name != ';') { 930 name = getoffset(name, &dstoffset); 931 if (name == NULL) 932 return -1; 933 } else 934 dstoffset = stdoffset - SECSPERHOUR; 935 if (*name == '\0' && load_result != 0) 936 name = TZDEFRULESTRING; 937 if (*name == ',' || *name == ';') { 938 struct rule start; 939 struct rule end; 940 int year; 941 time_t janfirst; 942 time_t starttime; 943 time_t endtime; 944 945 ++name; 946 if ((name = getrule(name, &start)) == NULL) 947 return -1; 948 if (*name++ != ',') 949 return -1; 950 if ((name = getrule(name, &end)) == NULL) 951 return -1; 952 if (*name != '\0') 953 return -1; 954 sp->typecnt = 2; /* standard time and DST */ 955 /* 956 ** Two transitions per year, from EPOCH_YEAR forward. 957 */ 958 sp->ttis[0] = sp->ttis[1] = zttinfo; 959 sp->ttis[0].tt_gmtoff = -dstoffset; 960 sp->ttis[0].tt_isdst = 1; 961 sp->ttis[0].tt_abbrind = stdlen + 1; 962 sp->ttis[1].tt_gmtoff = -stdoffset; 963 sp->ttis[1].tt_isdst = 0; 964 sp->ttis[1].tt_abbrind = 0; 965 atp = sp->ats; 966 typep = sp->types; 967 janfirst = 0; 968 sp->timecnt = 0; 969 for (year = EPOCH_YEAR; 970 sp->timecnt + 2 <= TZ_MAX_TIMES; 971 ++year) { 972 time_t newfirst; 973 974 starttime = transtime(janfirst, year, &start, 975 stdoffset); 976 endtime = transtime(janfirst, year, &end, 977 dstoffset); 978 if (starttime > endtime) { 979 *atp++ = endtime; 980 *typep++ = 1; /* DST ends */ 981 *atp++ = starttime; 982 *typep++ = 0; /* DST begins */ 983 } else { 984 *atp++ = starttime; 985 *typep++ = 0; /* DST begins */ 986 *atp++ = endtime; 987 *typep++ = 1; /* DST ends */ 988 } 989 sp->timecnt += 2; 990 newfirst = janfirst; 991 newfirst += year_lengths[isleap(year)] * 992 SECSPERDAY; 993 if (newfirst <= janfirst) 994 break; 995 janfirst = newfirst; 996 } 997 } else { 998 long theirstdoffset; 999 long theirdstoffset; 1000 long theiroffset; 1001 int isdst; 1002 int i; 1003 int j; 1004 1005 if (*name != '\0') 1006 return -1; 1007 /* 1008 ** Initial values of theirstdoffset and theirdstoffset. 1009 */ 1010 theirstdoffset = 0; 1011 for (i = 0; i < sp->timecnt; ++i) { 1012 j = sp->types[i]; 1013 if (!sp->ttis[j].tt_isdst) { 1014 theirstdoffset = 1015 -sp->ttis[j].tt_gmtoff; 1016 break; 1017 } 1018 } 1019 theirdstoffset = 0; 1020 for (i = 0; i < sp->timecnt; ++i) { 1021 j = sp->types[i]; 1022 if (sp->ttis[j].tt_isdst) { 1023 theirdstoffset = 1024 -sp->ttis[j].tt_gmtoff; 1025 break; 1026 } 1027 } 1028 /* 1029 ** Initially we're assumed to be in standard time. 1030 */ 1031 isdst = FALSE; 1032 theiroffset = theirstdoffset; 1033 /* 1034 ** Now juggle transition times and types 1035 ** tracking offsets as you do. 1036 */ 1037 for (i = 0; i < sp->timecnt; ++i) { 1038 j = sp->types[i]; 1039 sp->types[i] = sp->ttis[j].tt_isdst; 1040 if (sp->ttis[j].tt_ttisgmt) { 1041 /* No adjustment to transition time */ 1042 } else { 1043 /* 1044 ** If summer time is in effect, and the 1045 ** transition time was not specified as 1046 ** standard time, add the summer time 1047 ** offset to the transition time; 1048 ** otherwise, add the standard time 1049 ** offset to the transition time. 1050 */ 1051 /* 1052 ** Transitions from DST to DDST 1053 ** will effectively disappear since 1054 ** POSIX provides for only one DST 1055 ** offset. 1056 */ 1057 if (isdst && !sp->ttis[j].tt_ttisstd) { 1058 sp->ats[i] += dstoffset - 1059 theirdstoffset; 1060 } else { 1061 sp->ats[i] += stdoffset - 1062 theirstdoffset; 1063 } 1064 } 1065 theiroffset = -sp->ttis[j].tt_gmtoff; 1066 if (sp->ttis[j].tt_isdst) 1067 theirdstoffset = theiroffset; 1068 else 1069 theirstdoffset = theiroffset; 1070 } 1071 /* 1072 ** Finally, fill in ttis. 1073 */ 1074 sp->ttis[0] = sp->ttis[1] = zttinfo; 1075 sp->ttis[0].tt_gmtoff = -stdoffset; 1076 sp->ttis[0].tt_isdst = FALSE; 1077 sp->ttis[0].tt_abbrind = 0; 1078 sp->ttis[1].tt_gmtoff = -dstoffset; 1079 sp->ttis[1].tt_isdst = TRUE; 1080 sp->ttis[1].tt_abbrind = stdlen + 1; 1081 sp->typecnt = 2; 1082 } 1083 } else { 1084 dstlen = 0; 1085 sp->typecnt = 1; /* only standard time */ 1086 sp->timecnt = 0; 1087 sp->ttis[0] = zttinfo; 1088 sp->ttis[0].tt_gmtoff = -stdoffset; 1089 sp->ttis[0].tt_isdst = 0; 1090 sp->ttis[0].tt_abbrind = 0; 1091 } 1092 sp->charcnt = stdlen + 1; 1093 if (dstlen != 0) 1094 sp->charcnt += dstlen + 1; 1095 if ((size_t) sp->charcnt > sizeof sp->chars) 1096 return -1; 1097 cp = sp->chars; 1098 strlcpy(cp, stdname, stdlen + 1); 1099 cp += stdlen + 1; 1100 if (dstlen != 0) { 1101 strlcpy(cp, dstname, dstlen + 1); 1102 } 1103 return 0; 1104 } 1105 1106 static void 1107 gmtload(struct state *sp) 1108 { 1109 if (tzload(gmt, sp, TRUE) != 0) 1110 (void) tzparse(gmt, sp, TRUE); 1111 } 1112 1113 static void 1114 tzsetwall_basic(void) 1115 { 1116 if (lcl_is_set < 0) 1117 return; 1118 lcl_is_set = -1; 1119 1120 if (lclptr == NULL) { 1121 lclptr = calloc(1, sizeof *lclptr); 1122 if (lclptr == NULL) { 1123 settzname(); /* all we can do */ 1124 return; 1125 } 1126 } 1127 if (tzload(NULL, lclptr, TRUE) != 0) 1128 gmtload(lclptr); 1129 settzname(); 1130 } 1131 1132 #ifndef STD_INSPIRED 1133 /* 1134 ** A non-static declaration of tzsetwall in a system header file 1135 ** may cause a warning about this upcoming static declaration... 1136 */ 1137 static 1138 #endif /* !defined STD_INSPIRED */ 1139 void 1140 tzsetwall(void) 1141 { 1142 _THREAD_PRIVATE_MUTEX_LOCK(lcl); 1143 tzsetwall_basic(); 1144 _THREAD_PRIVATE_MUTEX_UNLOCK(lcl); 1145 } 1146 1147 static void 1148 tzset_basic(void) 1149 { 1150 const char * name; 1151 1152 if (issetugid() || (name = getenv("TZ")) == NULL) { 1153 tzsetwall_basic(); 1154 return; 1155 } 1156 1157 if (lcl_is_set > 0 && strcmp(lcl_TZname, name) == 0) 1158 return; 1159 lcl_is_set = strlen(name) < sizeof lcl_TZname; 1160 if (lcl_is_set) 1161 strlcpy(lcl_TZname, name, sizeof lcl_TZname); 1162 1163 if (lclptr == NULL) { 1164 lclptr = calloc(1, sizeof *lclptr); 1165 if (lclptr == NULL) { 1166 settzname(); /* all we can do */ 1167 return; 1168 } 1169 } 1170 if (*name == '\0') { 1171 /* 1172 ** User wants it fast rather than right. 1173 */ 1174 lclptr->leapcnt = 0; /* so, we're off a little */ 1175 lclptr->timecnt = 0; 1176 lclptr->typecnt = 0; 1177 lclptr->ttis[0].tt_isdst = 0; 1178 lclptr->ttis[0].tt_gmtoff = 0; 1179 lclptr->ttis[0].tt_abbrind = 0; 1180 strlcpy(lclptr->chars, gmt, sizeof lclptr->chars); 1181 } else if (tzload(name, lclptr, TRUE) != 0) { 1182 if (name[0] == ':' || tzparse(name, lclptr, FALSE) != 0) 1183 gmtload(lclptr); 1184 } 1185 settzname(); 1186 } 1187 1188 void 1189 tzset(void) 1190 { 1191 _THREAD_PRIVATE_MUTEX_LOCK(lcl); 1192 tzset_basic(); 1193 _THREAD_PRIVATE_MUTEX_UNLOCK(lcl); 1194 } 1195 DEF_WEAK(tzset); 1196 1197 /* 1198 ** The easy way to behave "as if no library function calls" localtime 1199 ** is to not call it--so we drop its guts into "localsub", which can be 1200 ** freely called. (And no, the PANS doesn't require the above behavior-- 1201 ** but it *is* desirable.) 1202 ** 1203 ** The unused offset argument is for the benefit of mktime variants. 1204 */ 1205 1206 static struct tm * 1207 localsub(const time_t *timep, long offset, struct tm *tmp) 1208 { 1209 struct state * sp; 1210 const struct ttinfo * ttisp; 1211 int i; 1212 struct tm * result; 1213 const time_t t = *timep; 1214 1215 sp = lclptr; 1216 if (sp == NULL) 1217 return gmtsub(timep, offset, tmp); 1218 if ((sp->goback && t < sp->ats[0]) || 1219 (sp->goahead && t > sp->ats[sp->timecnt - 1])) { 1220 time_t newt = t; 1221 time_t seconds; 1222 time_t tcycles; 1223 int_fast64_t icycles; 1224 1225 if (t < sp->ats[0]) 1226 seconds = sp->ats[0] - t; 1227 else 1228 seconds = t - sp->ats[sp->timecnt - 1]; 1229 --seconds; 1230 tcycles = seconds / YEARSPERREPEAT / AVGSECSPERYEAR; 1231 ++tcycles; 1232 icycles = tcycles; 1233 if (tcycles - icycles >= 1 || icycles - tcycles >= 1) 1234 return NULL; 1235 seconds = icycles; 1236 seconds *= YEARSPERREPEAT; 1237 seconds *= AVGSECSPERYEAR; 1238 if (t < sp->ats[0]) 1239 newt += seconds; 1240 else 1241 newt -= seconds; 1242 if (newt < sp->ats[0] || 1243 newt > sp->ats[sp->timecnt - 1]) 1244 return NULL; /* "cannot happen" */ 1245 result = localsub(&newt, offset, tmp); 1246 if (result == tmp) { 1247 time_t newy; 1248 1249 newy = tmp->tm_year; 1250 if (t < sp->ats[0]) 1251 newy -= icycles * YEARSPERREPEAT; 1252 else 1253 newy += icycles * YEARSPERREPEAT; 1254 tmp->tm_year = newy; 1255 if (tmp->tm_year != newy) 1256 return NULL; 1257 } 1258 return result; 1259 } 1260 if (sp->timecnt == 0 || t < sp->ats[0]) { 1261 i = 0; 1262 while (sp->ttis[i].tt_isdst) { 1263 if (++i >= sp->typecnt) { 1264 i = 0; 1265 break; 1266 } 1267 } 1268 } else { 1269 int lo = 1; 1270 int hi = sp->timecnt; 1271 1272 while (lo < hi) { 1273 int mid = (lo + hi) >> 1; 1274 1275 if (t < sp->ats[mid]) 1276 hi = mid; 1277 else 1278 lo = mid + 1; 1279 } 1280 i = (int) sp->types[lo - 1]; 1281 } 1282 ttisp = &sp->ttis[i]; 1283 /* 1284 ** To get (wrong) behavior that's compatible with System V Release 2.0 1285 ** you'd replace the statement below with 1286 ** t += ttisp->tt_gmtoff; 1287 ** timesub(&t, 0L, sp, tmp); 1288 */ 1289 result = timesub(&t, ttisp->tt_gmtoff, sp, tmp); 1290 tmp->tm_isdst = ttisp->tt_isdst; 1291 tzname[tmp->tm_isdst] = &sp->chars[ttisp->tt_abbrind]; 1292 tmp->tm_zone = &sp->chars[ttisp->tt_abbrind]; 1293 return result; 1294 } 1295 1296 /* 1297 ** Re-entrant version of localtime. 1298 */ 1299 1300 struct tm * 1301 localtime_r(const time_t *timep, struct tm *p_tm) 1302 { 1303 _THREAD_PRIVATE_MUTEX_LOCK(lcl); 1304 tzset_basic(); 1305 p_tm = localsub(timep, 0L, p_tm); 1306 _THREAD_PRIVATE_MUTEX_UNLOCK(lcl); 1307 return p_tm; 1308 } 1309 DEF_WEAK(localtime_r); 1310 1311 struct tm * 1312 localtime(const time_t *timep) 1313 { 1314 _THREAD_PRIVATE_KEY(localtime); 1315 struct tm * p_tm = (struct tm*)_THREAD_PRIVATE(localtime, tm, NULL); 1316 1317 if (p_tm == NULL) 1318 return NULL; 1319 return localtime_r(timep, p_tm); 1320 } 1321 DEF_STRONG(localtime); 1322 1323 /* 1324 ** gmtsub is to gmtime as localsub is to localtime. 1325 */ 1326 1327 static struct tm * 1328 gmtsub(const time_t *timep, long offset, struct tm *tmp) 1329 { 1330 struct tm * result; 1331 1332 _THREAD_PRIVATE_MUTEX_LOCK(gmt); 1333 if (!gmt_is_set) { 1334 gmt_is_set = TRUE; 1335 gmtptr = calloc(1, sizeof(*gmtptr)); 1336 if (gmtptr != NULL) 1337 gmtload(gmtptr); 1338 } 1339 _THREAD_PRIVATE_MUTEX_UNLOCK(gmt); 1340 result = timesub(timep, offset, gmtptr, tmp); 1341 /* 1342 ** Could get fancy here and deliver something such as 1343 ** "UTC+xxxx" or "UTC-xxxx" if offset is non-zero, 1344 ** but this is no time for a treasure hunt. 1345 */ 1346 if (offset != 0) 1347 tmp->tm_zone = wildabbr; 1348 else { 1349 if (gmtptr == NULL) 1350 tmp->tm_zone = (char *)gmt; 1351 else 1352 tmp->tm_zone = gmtptr->chars; 1353 } 1354 return result; 1355 } 1356 1357 /* 1358 ** Re-entrant version of gmtime. 1359 */ 1360 1361 struct tm * 1362 gmtime_r(const time_t *timep, struct tm *p_tm) 1363 { 1364 return gmtsub(timep, 0L, p_tm); 1365 } 1366 DEF_WEAK(gmtime_r); 1367 1368 struct tm * 1369 gmtime(const time_t *timep) 1370 { 1371 _THREAD_PRIVATE_KEY(gmtime); 1372 struct tm * p_tm = (struct tm*) _THREAD_PRIVATE(gmtime, tm, NULL); 1373 1374 if (p_tm == NULL) 1375 return NULL; 1376 return gmtime_r(timep, p_tm); 1377 1378 } 1379 DEF_WEAK(gmtime); 1380 1381 #ifdef STD_INSPIRED 1382 1383 struct tm * 1384 offtime(const time_t *timep, long offset) 1385 { 1386 return gmtsub(timep, offset, &tm); 1387 } 1388 1389 #endif /* defined STD_INSPIRED */ 1390 1391 /* 1392 ** Return the number of leap years through the end of the given year 1393 ** where, to make the math easy, the answer for year zero is defined as zero. 1394 */ 1395 1396 static int 1397 leaps_thru_end_of(int y) 1398 { 1399 return (y >= 0) ? (y / 4 - y / 100 + y / 400) : 1400 -(leaps_thru_end_of(-(y + 1)) + 1); 1401 } 1402 1403 static struct tm * 1404 timesub(const time_t *timep, long offset, const struct state *sp, struct tm *tmp) 1405 { 1406 const struct lsinfo * lp; 1407 time_t tdays; 1408 int idays; /* unsigned would be so 2003 */ 1409 long rem; 1410 int y; 1411 const int * ip; 1412 long corr; 1413 int hit; 1414 int i; 1415 long seconds; 1416 1417 corr = 0; 1418 hit = 0; 1419 i = (sp == NULL) ? 0 : sp->leapcnt; 1420 while (--i >= 0) { 1421 lp = &sp->lsis[i]; 1422 if (*timep >= lp->ls_trans) { 1423 if (*timep == lp->ls_trans) { 1424 hit = ((i == 0 && lp->ls_corr > 0) || 1425 lp->ls_corr > sp->lsis[i - 1].ls_corr); 1426 if (hit) { 1427 while (i > 0 && 1428 sp->lsis[i].ls_trans == 1429 sp->lsis[i - 1].ls_trans + 1 && 1430 sp->lsis[i].ls_corr == 1431 sp->lsis[i - 1].ls_corr + 1) { 1432 ++hit; 1433 --i; 1434 } 1435 } 1436 } 1437 corr = lp->ls_corr; 1438 break; 1439 } 1440 } 1441 y = EPOCH_YEAR; 1442 tdays = *timep / SECSPERDAY; 1443 rem = *timep - tdays * SECSPERDAY; 1444 while (tdays < 0 || tdays >= year_lengths[isleap(y)]) { 1445 int newy; 1446 time_t tdelta; 1447 int idelta; 1448 int leapdays; 1449 1450 tdelta = tdays / DAYSPERLYEAR; 1451 idelta = tdelta; 1452 if (tdelta - idelta >= 1 || idelta - tdelta >= 1) 1453 return NULL; 1454 if (idelta == 0) 1455 idelta = (tdays < 0) ? -1 : 1; 1456 newy = y; 1457 if (increment_overflow(&newy, idelta)) 1458 return NULL; 1459 leapdays = leaps_thru_end_of(newy - 1) - 1460 leaps_thru_end_of(y - 1); 1461 tdays -= ((time_t) newy - y) * DAYSPERNYEAR; 1462 tdays -= leapdays; 1463 y = newy; 1464 } 1465 1466 seconds = tdays * SECSPERDAY + 0.5; 1467 tdays = seconds / SECSPERDAY; 1468 rem += seconds - tdays * SECSPERDAY; 1469 1470 /* 1471 ** Given the range, we can now fearlessly cast... 1472 */ 1473 idays = tdays; 1474 rem += offset - corr; 1475 while (rem < 0) { 1476 rem += SECSPERDAY; 1477 --idays; 1478 } 1479 while (rem >= SECSPERDAY) { 1480 rem -= SECSPERDAY; 1481 ++idays; 1482 } 1483 while (idays < 0) { 1484 if (increment_overflow(&y, -1)) 1485 return NULL; 1486 idays += year_lengths[isleap(y)]; 1487 } 1488 while (idays >= year_lengths[isleap(y)]) { 1489 idays -= year_lengths[isleap(y)]; 1490 if (increment_overflow(&y, 1)) 1491 return NULL; 1492 } 1493 tmp->tm_year = y; 1494 if (increment_overflow(&tmp->tm_year, -TM_YEAR_BASE)) 1495 return NULL; 1496 tmp->tm_yday = idays; 1497 /* 1498 ** The "extra" mods below avoid overflow problems. 1499 */ 1500 tmp->tm_wday = EPOCH_WDAY + 1501 ((y - EPOCH_YEAR) % DAYSPERWEEK) * 1502 (DAYSPERNYEAR % DAYSPERWEEK) + 1503 leaps_thru_end_of(y - 1) - 1504 leaps_thru_end_of(EPOCH_YEAR - 1) + 1505 idays; 1506 tmp->tm_wday %= DAYSPERWEEK; 1507 if (tmp->tm_wday < 0) 1508 tmp->tm_wday += DAYSPERWEEK; 1509 tmp->tm_hour = (int) (rem / SECSPERHOUR); 1510 rem %= SECSPERHOUR; 1511 tmp->tm_min = (int) (rem / SECSPERMIN); 1512 /* 1513 ** A positive leap second requires a special 1514 ** representation. This uses "... ??:59:60" et seq. 1515 */ 1516 tmp->tm_sec = (int) (rem % SECSPERMIN) + hit; 1517 ip = mon_lengths[isleap(y)]; 1518 for (tmp->tm_mon = 0; idays >= ip[tmp->tm_mon]; ++(tmp->tm_mon)) 1519 idays -= ip[tmp->tm_mon]; 1520 tmp->tm_mday = (int) (idays + 1); 1521 tmp->tm_isdst = 0; 1522 tmp->tm_gmtoff = offset; 1523 return tmp; 1524 } 1525 1526 char * 1527 ctime(const time_t *timep) 1528 { 1529 /* 1530 ** Section 4.12.3.2 of X3.159-1989 requires that 1531 ** The ctime function converts the calendar time pointed to by timer 1532 ** to local time in the form of a string. It is equivalent to 1533 ** asctime(localtime(timer)) 1534 */ 1535 return asctime(localtime(timep)); 1536 } 1537 1538 char * 1539 ctime_r(const time_t *timep, char *buf) 1540 { 1541 struct tm mytm; 1542 1543 return asctime_r(localtime_r(timep, &mytm), buf); 1544 } 1545 1546 /* 1547 ** Adapted from code provided by Robert Elz, who writes: 1548 ** The "best" way to do mktime I think is based on an idea of Bob 1549 ** Kridle's (so its said...) from a long time ago. 1550 ** It does a binary search of the time_t space. Since time_t's are 1551 ** just 32 bits, its a max of 32 iterations (even at 64 bits it 1552 ** would still be very reasonable). 1553 */ 1554 1555 #ifndef WRONG 1556 #define WRONG (-1) 1557 #endif /* !defined WRONG */ 1558 1559 /* 1560 ** Normalize logic courtesy Paul Eggert. 1561 */ 1562 1563 static int 1564 increment_overflow(int *ip, int j) 1565 { 1566 int const i = *ip; 1567 1568 /* 1569 ** If i >= 0 there can only be overflow if i + j > INT_MAX 1570 ** or if j > INT_MAX - i; given i >= 0, INT_MAX - i cannot overflow. 1571 ** If i < 0 there can only be overflow if i + j < INT_MIN 1572 ** or if j < INT_MIN - i; given i < 0, INT_MIN - i cannot overflow. 1573 */ 1574 if ((i >= 0) ? (j > INT_MAX - i) : (j < INT_MIN - i)) 1575 return TRUE; 1576 *ip += j; 1577 return FALSE; 1578 } 1579 1580 static int 1581 long_increment_overflow(long *lp, int m) 1582 { 1583 long const l = *lp; 1584 1585 if ((l >= 0) ? (m > LONG_MAX - l) : (m < LONG_MIN - l)) 1586 return TRUE; 1587 *lp += m; 1588 return FALSE; 1589 } 1590 1591 static int 1592 normalize_overflow(int *tensptr, int *unitsptr, 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 increment_overflow(tensptr, tensdelta); 1601 } 1602 1603 static int 1604 long_normalize_overflow(long *tensptr, int *unitsptr, int base) 1605 { 1606 int tensdelta; 1607 1608 tensdelta = (*unitsptr >= 0) ? 1609 (*unitsptr / base) : 1610 (-1 - (-1 - *unitsptr) / base); 1611 *unitsptr -= tensdelta * base; 1612 return long_increment_overflow(tensptr, tensdelta); 1613 } 1614 1615 static int 1616 tmcomp(const struct tm *atmp, const struct tm *btmp) 1617 { 1618 int result; 1619 1620 if ((result = (atmp->tm_year - btmp->tm_year)) == 0 && 1621 (result = (atmp->tm_mon - btmp->tm_mon)) == 0 && 1622 (result = (atmp->tm_mday - btmp->tm_mday)) == 0 && 1623 (result = (atmp->tm_hour - btmp->tm_hour)) == 0 && 1624 (result = (atmp->tm_min - btmp->tm_min)) == 0) 1625 result = atmp->tm_sec - btmp->tm_sec; 1626 return result; 1627 } 1628 1629 static time_t 1630 time2sub(struct tm *tmp, struct tm *(*funcp)(const time_t *, long, struct tm *), 1631 long offset, int *okayp, int do_norm_secs) 1632 { 1633 const struct state * sp; 1634 int dir; 1635 int i, j; 1636 int saved_seconds; 1637 long li; 1638 time_t lo; 1639 time_t hi; 1640 long y; 1641 time_t newt; 1642 time_t t; 1643 struct tm yourtm, mytm; 1644 1645 *okayp = FALSE; 1646 yourtm = *tmp; 1647 if (do_norm_secs) { 1648 if (normalize_overflow(&yourtm.tm_min, &yourtm.tm_sec, 1649 SECSPERMIN)) 1650 return WRONG; 1651 } 1652 if (normalize_overflow(&yourtm.tm_hour, &yourtm.tm_min, MINSPERHOUR)) 1653 return WRONG; 1654 if (normalize_overflow(&yourtm.tm_mday, &yourtm.tm_hour, HOURSPERDAY)) 1655 return WRONG; 1656 y = yourtm.tm_year; 1657 if (long_normalize_overflow(&y, &yourtm.tm_mon, MONSPERYEAR)) 1658 return WRONG; 1659 /* 1660 ** Turn y into an actual year number for now. 1661 ** It is converted back to an offset from TM_YEAR_BASE later. 1662 */ 1663 if (long_increment_overflow(&y, TM_YEAR_BASE)) 1664 return WRONG; 1665 while (yourtm.tm_mday <= 0) { 1666 if (long_increment_overflow(&y, -1)) 1667 return WRONG; 1668 li = y + (1 < yourtm.tm_mon); 1669 yourtm.tm_mday += year_lengths[isleap(li)]; 1670 } 1671 while (yourtm.tm_mday > DAYSPERLYEAR) { 1672 li = y + (1 < yourtm.tm_mon); 1673 yourtm.tm_mday -= year_lengths[isleap(li)]; 1674 if (long_increment_overflow(&y, 1)) 1675 return WRONG; 1676 } 1677 for ( ; ; ) { 1678 i = mon_lengths[isleap(y)][yourtm.tm_mon]; 1679 if (yourtm.tm_mday <= i) 1680 break; 1681 yourtm.tm_mday -= i; 1682 if (++yourtm.tm_mon >= MONSPERYEAR) { 1683 yourtm.tm_mon = 0; 1684 if (long_increment_overflow(&y, 1)) 1685 return WRONG; 1686 } 1687 } 1688 if (long_increment_overflow(&y, -TM_YEAR_BASE)) 1689 return WRONG; 1690 yourtm.tm_year = y; 1691 if (yourtm.tm_year != y) 1692 return WRONG; 1693 if (yourtm.tm_sec >= 0 && yourtm.tm_sec < SECSPERMIN) 1694 saved_seconds = 0; 1695 else if (y + TM_YEAR_BASE < EPOCH_YEAR) { 1696 /* 1697 ** We can't set tm_sec to 0, because that might push the 1698 ** time below the minimum representable time. 1699 ** Set tm_sec to 59 instead. 1700 ** This assumes that the minimum representable time is 1701 ** not in the same minute that a leap second was deleted from, 1702 ** which is a safer assumption than using 58 would be. 1703 */ 1704 if (increment_overflow(&yourtm.tm_sec, 1 - SECSPERMIN)) 1705 return WRONG; 1706 saved_seconds = yourtm.tm_sec; 1707 yourtm.tm_sec = SECSPERMIN - 1; 1708 } else { 1709 saved_seconds = yourtm.tm_sec; 1710 yourtm.tm_sec = 0; 1711 } 1712 /* 1713 ** Do a binary search (this works whatever time_t's type is). 1714 */ 1715 lo = 1; 1716 for (i = 0; i < (int) TYPE_BIT(time_t) - 1; ++i) 1717 lo *= 2; 1718 hi = -(lo + 1); 1719 for ( ; ; ) { 1720 t = lo / 2 + hi / 2; 1721 if (t < lo) 1722 t = lo; 1723 else if (t > hi) 1724 t = hi; 1725 if ((*funcp)(&t, offset, &mytm) == NULL) { 1726 /* 1727 ** Assume that t is too extreme to be represented in 1728 ** a struct tm; arrange things so that it is less 1729 ** extreme on the next pass. 1730 */ 1731 dir = (t > 0) ? 1 : -1; 1732 } else 1733 dir = tmcomp(&mytm, &yourtm); 1734 if (dir != 0) { 1735 if (t == lo) { 1736 ++t; 1737 if (t <= lo) 1738 return WRONG; 1739 ++lo; 1740 } else if (t == hi) { 1741 --t; 1742 if (t >= hi) 1743 return WRONG; 1744 --hi; 1745 } 1746 if (lo > hi) 1747 return WRONG; 1748 if (dir > 0) 1749 hi = t; 1750 else 1751 lo = t; 1752 continue; 1753 } 1754 if (yourtm.tm_isdst < 0 || mytm.tm_isdst == yourtm.tm_isdst) 1755 break; 1756 /* 1757 ** Right time, wrong type. 1758 ** Hunt for right time, right type. 1759 ** It's okay to guess wrong since the guess 1760 ** gets checked. 1761 */ 1762 sp = (const struct state *) 1763 ((funcp == localsub) ? lclptr : gmtptr); 1764 if (sp == NULL) 1765 return WRONG; 1766 for (i = sp->typecnt - 1; i >= 0; --i) { 1767 if (sp->ttis[i].tt_isdst != yourtm.tm_isdst) 1768 continue; 1769 for (j = sp->typecnt - 1; j >= 0; --j) { 1770 if (sp->ttis[j].tt_isdst == yourtm.tm_isdst) 1771 continue; 1772 newt = t + sp->ttis[j].tt_gmtoff - 1773 sp->ttis[i].tt_gmtoff; 1774 if ((*funcp)(&newt, offset, &mytm) == NULL) 1775 continue; 1776 if (tmcomp(&mytm, &yourtm) != 0) 1777 continue; 1778 if (mytm.tm_isdst != yourtm.tm_isdst) 1779 continue; 1780 /* 1781 ** We have a match. 1782 */ 1783 t = newt; 1784 goto label; 1785 } 1786 } 1787 return WRONG; 1788 } 1789 label: 1790 newt = t + saved_seconds; 1791 if ((newt < t) != (saved_seconds < 0)) 1792 return WRONG; 1793 t = newt; 1794 if ((*funcp)(&t, offset, tmp)) 1795 *okayp = TRUE; 1796 return t; 1797 } 1798 1799 static time_t 1800 time2(struct tm *tmp, struct tm * (*funcp)(const time_t *, long, struct tm *), 1801 long offset, int *okayp) 1802 { 1803 time_t t; 1804 1805 /* 1806 ** First try without normalization of seconds 1807 ** (in case tm_sec contains a value associated with a leap second). 1808 ** If that fails, try with normalization of seconds. 1809 */ 1810 t = time2sub(tmp, funcp, offset, okayp, FALSE); 1811 return *okayp ? t : time2sub(tmp, funcp, offset, okayp, TRUE); 1812 } 1813 1814 static time_t 1815 time1(struct tm *tmp, struct tm * (*funcp)(const time_t *, long, struct tm *), 1816 long offset) 1817 { 1818 time_t t; 1819 const struct state * sp; 1820 int samei, otheri; 1821 int sameind, otherind; 1822 int i; 1823 int nseen; 1824 int seen[TZ_MAX_TYPES]; 1825 int types[TZ_MAX_TYPES]; 1826 int okay; 1827 1828 if (tmp == NULL) { 1829 errno = EINVAL; 1830 return WRONG; 1831 } 1832 if (tmp->tm_isdst > 1) 1833 tmp->tm_isdst = 1; 1834 t = time2(tmp, funcp, offset, &okay); 1835 #ifdef PCTS 1836 /* 1837 ** PCTS code courtesy Grant Sullivan. 1838 */ 1839 if (okay) 1840 return t; 1841 if (tmp->tm_isdst < 0) 1842 tmp->tm_isdst = 0; /* reset to std and try again */ 1843 #endif /* defined PCTS */ 1844 #ifndef PCTS 1845 if (okay || tmp->tm_isdst < 0) 1846 return t; 1847 #endif /* !defined PCTS */ 1848 /* 1849 ** We're supposed to assume that somebody took a time of one type 1850 ** and did some math on it that yielded a "struct tm" that's bad. 1851 ** We try to divine the type they started from and adjust to the 1852 ** type they need. 1853 */ 1854 sp = (const struct state *) ((funcp == localsub) ? lclptr : gmtptr); 1855 if (sp == NULL) 1856 return WRONG; 1857 for (i = 0; i < sp->typecnt; ++i) 1858 seen[i] = FALSE; 1859 nseen = 0; 1860 for (i = sp->timecnt - 1; i >= 0; --i) { 1861 if (!seen[sp->types[i]]) { 1862 seen[sp->types[i]] = TRUE; 1863 types[nseen++] = sp->types[i]; 1864 } 1865 } 1866 for (sameind = 0; sameind < nseen; ++sameind) { 1867 samei = types[sameind]; 1868 if (sp->ttis[samei].tt_isdst != tmp->tm_isdst) 1869 continue; 1870 for (otherind = 0; otherind < nseen; ++otherind) { 1871 otheri = types[otherind]; 1872 if (sp->ttis[otheri].tt_isdst == tmp->tm_isdst) 1873 continue; 1874 tmp->tm_sec += sp->ttis[otheri].tt_gmtoff - 1875 sp->ttis[samei].tt_gmtoff; 1876 tmp->tm_isdst = !tmp->tm_isdst; 1877 t = time2(tmp, funcp, offset, &okay); 1878 if (okay) 1879 return t; 1880 tmp->tm_sec -= sp->ttis[otheri].tt_gmtoff - 1881 sp->ttis[samei].tt_gmtoff; 1882 tmp->tm_isdst = !tmp->tm_isdst; 1883 } 1884 } 1885 return WRONG; 1886 } 1887 1888 time_t 1889 mktime(struct tm *tmp) 1890 { 1891 time_t ret; 1892 1893 _THREAD_PRIVATE_MUTEX_LOCK(lcl); 1894 tzset_basic(); 1895 ret = time1(tmp, localsub, 0L); 1896 _THREAD_PRIVATE_MUTEX_UNLOCK(lcl); 1897 return ret; 1898 } 1899 DEF_STRONG(mktime); 1900 1901 #ifdef STD_INSPIRED 1902 1903 time_t 1904 timelocal(struct tm *tmp) 1905 { 1906 if (tmp != NULL) 1907 tmp->tm_isdst = -1; /* in case it wasn't initialized */ 1908 return mktime(tmp); 1909 } 1910 1911 time_t 1912 timegm(struct tm *tmp) 1913 { 1914 if (tmp != NULL) 1915 tmp->tm_isdst = 0; 1916 return time1(tmp, gmtsub, 0L); 1917 } 1918 1919 time_t 1920 timeoff(struct tm *tmp, long offset) 1921 { 1922 if (tmp != NULL) 1923 tmp->tm_isdst = 0; 1924 return time1(tmp, gmtsub, offset); 1925 } 1926 1927 #endif /* defined STD_INSPIRED */ 1928 1929 /* 1930 ** XXX--is the below the right way to conditionalize?? 1931 */ 1932 1933 #ifdef STD_INSPIRED 1934 1935 /* 1936 ** IEEE Std 1003.1-1988 (POSIX) legislates that 536457599 1937 ** shall correspond to "Wed Dec 31 23:59:59 UTC 1986", which 1938 ** is not the case if we are accounting for leap seconds. 1939 ** So, we provide the following conversion routines for use 1940 ** when exchanging timestamps with POSIX conforming systems. 1941 */ 1942 1943 static long 1944 leapcorr(time_t *timep) 1945 { 1946 struct state * sp; 1947 struct lsinfo * lp; 1948 int i; 1949 1950 sp = lclptr; 1951 i = sp->leapcnt; 1952 while (--i >= 0) { 1953 lp = &sp->lsis[i]; 1954 if (*timep >= lp->ls_trans) 1955 return lp->ls_corr; 1956 } 1957 return 0; 1958 } 1959 1960 time_t 1961 time2posix(time_t t) 1962 { 1963 tzset(); 1964 return t - leapcorr(&t); 1965 } 1966 1967 time_t 1968 posix2time(time_t t) 1969 { 1970 time_t x; 1971 time_t y; 1972 1973 tzset(); 1974 /* 1975 ** For a positive leap second hit, the result 1976 ** is not unique. For a negative leap second 1977 ** hit, the corresponding time doesn't exist, 1978 ** so we return an adjacent second. 1979 */ 1980 x = t + leapcorr(&t); 1981 y = x - leapcorr(&x); 1982 if (y < t) { 1983 do { 1984 x++; 1985 y = x - leapcorr(&x); 1986 } while (y < t); 1987 if (t != y) 1988 return x - 1; 1989 } else if (y > t) { 1990 do { 1991 --x; 1992 y = x - leapcorr(&x); 1993 } while (y > t); 1994 if (t != y) 1995 return x + 1; 1996 } 1997 return x; 1998 } 1999 2000 #endif /* defined STD_INSPIRED */ 2001