1 /* $OpenBSD: localtime.c,v 1.59 2016/09/19 12:48:21 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 <float.h> /* for FLT_MAX and DBL_MAX */ 16 #include <stdint.h> 17 #include <stdlib.h> 18 #include <string.h> 19 #include <unistd.h> 20 21 #include "private.h" 22 #include "tzfile.h" 23 #include "thread_private.h" 24 25 #ifndef TZ_ABBR_MAX_LEN 26 #define TZ_ABBR_MAX_LEN 16 27 #endif /* !defined TZ_ABBR_MAX_LEN */ 28 29 #ifndef TZ_ABBR_CHAR_SET 30 #define TZ_ABBR_CHAR_SET \ 31 "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789 :+-._" 32 #endif /* !defined TZ_ABBR_CHAR_SET */ 33 34 #ifndef TZ_ABBR_ERR_CHAR 35 #define TZ_ABBR_ERR_CHAR '_' 36 #endif /* !defined TZ_ABBR_ERR_CHAR */ 37 38 #ifndef WILDABBR 39 /* 40 ** Someone might make incorrect use of a time zone abbreviation: 41 ** 1. They might reference tzname[0] before calling tzset (explicitly 42 ** or implicitly). 43 ** 2. They might reference tzname[1] before calling tzset (explicitly 44 ** or implicitly). 45 ** 3. They might reference tzname[1] after setting to a time zone 46 ** in which Daylight Saving Time is never observed. 47 ** 4. They might reference tzname[0] after setting to a time zone 48 ** in which Standard Time is never observed. 49 ** 5. They might reference tm.TM_ZONE after calling offtime. 50 ** What's best to do in the above cases is open to debate; 51 ** for now, we just set things up so that in any of the five cases 52 ** WILDABBR is used. Another possibility: initialize tzname[0] to the 53 ** string "tzname[0] used before set", and similarly for the other cases. 54 ** And another: initialize tzname[0] to "ERA", with an explanation in the 55 ** manual page of what this "time zone abbreviation" means (doing this so 56 ** that tzname[0] has the "normal" length of three characters). 57 */ 58 #define WILDABBR " " 59 #endif /* !defined WILDABBR */ 60 61 static char wildabbr[] = WILDABBR; 62 63 static const char gmt[] = "GMT"; 64 65 /* 66 ** The DST rules to use if TZ has no rules and we can't load TZDEFRULES. 67 ** We default to US rules as of 1999-08-17. 68 ** POSIX 1003.1 section 8.1.1 says that the default DST rules are 69 ** implementation dependent; for historical reasons, US rules are a 70 ** common default. 71 */ 72 #ifndef TZDEFRULESTRING 73 #define TZDEFRULESTRING ",M4.1.0,M10.5.0" 74 #endif /* !defined TZDEFDST */ 75 76 struct ttinfo { /* time type information */ 77 long tt_gmtoff; /* UTC offset in seconds */ 78 int tt_isdst; /* used to set tm_isdst */ 79 int tt_abbrind; /* abbreviation list index */ 80 int tt_ttisstd; /* TRUE if transition is std time */ 81 int tt_ttisgmt; /* TRUE if transition is UTC */ 82 }; 83 84 struct lsinfo { /* leap second information */ 85 time_t ls_trans; /* transition time */ 86 long ls_corr; /* correction to apply */ 87 }; 88 89 #define BIGGEST(a, b) (((a) > (b)) ? (a) : (b)) 90 91 #ifdef TZNAME_MAX 92 #define MY_TZNAME_MAX TZNAME_MAX 93 #endif /* defined TZNAME_MAX */ 94 #ifndef TZNAME_MAX 95 #define MY_TZNAME_MAX 255 96 #endif /* !defined TZNAME_MAX */ 97 98 struct state { 99 int leapcnt; 100 int timecnt; 101 int typecnt; 102 int charcnt; 103 int goback; 104 int goahead; 105 time_t ats[TZ_MAX_TIMES]; 106 unsigned char types[TZ_MAX_TIMES]; 107 struct ttinfo ttis[TZ_MAX_TYPES]; 108 char chars[BIGGEST(BIGGEST(TZ_MAX_CHARS + 1, sizeof gmt), 109 (2 * (MY_TZNAME_MAX + 1)))]; 110 struct lsinfo lsis[TZ_MAX_LEAPS]; 111 }; 112 113 struct rule { 114 int r_type; /* type of rule--see below */ 115 int r_day; /* day number of rule */ 116 int r_week; /* week number of rule */ 117 int r_mon; /* month number of rule */ 118 long r_time; /* transition time of rule */ 119 }; 120 121 #define JULIAN_DAY 0 /* Jn - Julian day */ 122 #define DAY_OF_YEAR 1 /* n - day of year */ 123 #define MONTH_NTH_DAY_OF_WEEK 2 /* Mm.n.d - month, week, day of week */ 124 125 /* 126 ** Prototypes for static functions. 127 */ 128 129 static long detzcode(const char * codep); 130 static time_t detzcode64(const char * codep); 131 static int differ_by_repeat(time_t t1, time_t t0); 132 static const char * getzname(const char * strp); 133 static const char * getqzname(const char * strp, const int delim); 134 static const char * getnum(const char * strp, int * nump, int min, 135 int max); 136 static const char * getsecs(const char * strp, long * secsp); 137 static const char * getoffset(const char * strp, long * offsetp); 138 static const char * getrule(const char * strp, struct rule * rulep); 139 static void gmtload(struct state * sp); 140 static struct tm * gmtsub(const time_t * timep, long offset, 141 struct tm * tmp); 142 static struct tm * localsub(const time_t * timep, long offset, 143 struct tm * tmp); 144 static int increment_overflow(int * number, int delta); 145 static int leaps_thru_end_of(int y); 146 static int long_increment_overflow(long * number, int delta); 147 static int long_normalize_overflow(long * tensptr, 148 int * unitsptr, int base); 149 static int normalize_overflow(int * tensptr, int * unitsptr, 150 int base); 151 static void settzname(void); 152 static time_t time1(struct tm * tmp, 153 struct tm * (*funcp)(const time_t *, 154 long, struct tm *), 155 long offset); 156 static time_t time2(struct tm *tmp, 157 struct tm * (*funcp)(const time_t *, 158 long, struct tm*), 159 long offset, int * okayp); 160 static time_t time2sub(struct tm *tmp, 161 struct tm * (*funcp)(const time_t *, 162 long, struct tm*), 163 long offset, int * okayp, int do_norm_secs); 164 static struct tm * timesub(const time_t * timep, long offset, 165 const struct state * sp, struct tm * tmp); 166 static int tmcomp(const struct tm * atmp, 167 const struct tm * btmp); 168 static time_t transtime(time_t janfirst, int year, 169 const struct rule * rulep, long offset); 170 static int typesequiv(const struct state * sp, int a, int b); 171 static int tzload(const char * name, struct state * sp, 172 int doextend); 173 static int tzparse(const char * name, struct state * sp, 174 int lastditch); 175 176 #ifdef STD_INSPIRED 177 struct tm *offtime(const time_t *, long); 178 time_t time2posix(time_t); 179 time_t posix2time(time_t); 180 PROTO_DEPRECATED(offtime); 181 PROTO_DEPRECATED(time2posix); 182 PROTO_DEPRECATED(posix2time); 183 #endif 184 185 static struct state * lclptr; 186 static struct state * gmtptr; 187 188 189 #ifndef TZ_STRLEN_MAX 190 #define TZ_STRLEN_MAX 255 191 #endif /* !defined TZ_STRLEN_MAX */ 192 193 static char lcl_TZname[TZ_STRLEN_MAX + 1]; 194 static int lcl_is_set; 195 static int gmt_is_set; 196 _THREAD_PRIVATE_MUTEX(lcl); 197 _THREAD_PRIVATE_MUTEX(gmt); 198 199 char * tzname[2] = { 200 wildabbr, 201 wildabbr 202 }; 203 #if 0 204 DEF_WEAK(tzname); 205 #endif 206 207 /* 208 ** Section 4.12.3 of X3.159-1989 requires that 209 ** Except for the strftime function, these functions [asctime, 210 ** ctime, gmtime, localtime] return values in one of two static 211 ** objects: a broken-down time structure and an array of char. 212 ** Thanks to Paul Eggert for noting this. 213 */ 214 215 static struct tm tm; 216 217 #ifdef USG_COMPAT 218 long timezone = 0; 219 int daylight = 0; 220 #endif /* defined USG_COMPAT */ 221 222 #ifdef ALTZONE 223 time_t altzone = 0; 224 #endif /* defined ALTZONE */ 225 226 static long 227 detzcode(const char *codep) 228 { 229 long result; 230 int i; 231 232 result = (codep[0] & 0x80) ? ~0L : 0; 233 for (i = 0; i < 4; ++i) 234 result = (result << 8) | (codep[i] & 0xff); 235 return result; 236 } 237 238 static time_t 239 detzcode64(const char *codep) 240 { 241 time_t result; 242 int i; 243 244 result = (codep[0] & 0x80) ? (~(int_fast64_t) 0) : 0; 245 for (i = 0; i < 8; ++i) 246 result = result * 256 + (codep[i] & 0xff); 247 return result; 248 } 249 250 static void 251 settzname(void) 252 { 253 struct state * const sp = lclptr; 254 int i; 255 256 tzname[0] = wildabbr; 257 tzname[1] = wildabbr; 258 #ifdef USG_COMPAT 259 daylight = 0; 260 timezone = 0; 261 #endif /* defined USG_COMPAT */ 262 #ifdef ALTZONE 263 altzone = 0; 264 #endif /* defined ALTZONE */ 265 if (sp == NULL) { 266 tzname[0] = tzname[1] = (char *)gmt; 267 return; 268 } 269 /* 270 ** And to get the latest zone names into tzname. . . 271 */ 272 for (i = 0; i < sp->timecnt; ++i) { 273 const struct ttinfo *ttisp = &sp->ttis[sp->types[i]]; 274 275 tzname[ttisp->tt_isdst] = &sp->chars[ttisp->tt_abbrind]; 276 #ifdef USG_COMPAT 277 if (ttisp->tt_isdst) 278 daylight = 1; 279 if (!ttisp->tt_isdst) 280 timezone = -(ttisp->tt_gmtoff); 281 #endif /* defined USG_COMPAT */ 282 #ifdef ALTZONE 283 if (ttisp->tt_isdst) 284 altzone = -(ttisp->tt_gmtoff); 285 #endif /* defined ALTZONE */ 286 } 287 /* 288 ** Finally, scrub the abbreviations. 289 ** First, replace bogus characters. 290 */ 291 for (i = 0; i < sp->charcnt; ++i) { 292 if (strchr(TZ_ABBR_CHAR_SET, sp->chars[i]) == NULL) 293 sp->chars[i] = TZ_ABBR_ERR_CHAR; 294 } 295 /* 296 ** Second, truncate long abbreviations. 297 */ 298 for (i = 0; i < sp->typecnt; ++i) { 299 const struct ttinfo *ttisp = &sp->ttis[i]; 300 char *cp = &sp->chars[ttisp->tt_abbrind]; 301 302 if (strlen(cp) > TZ_ABBR_MAX_LEN && 303 strcmp(cp, GRANDPARENTED) != 0) 304 *(cp + TZ_ABBR_MAX_LEN) = '\0'; 305 } 306 } 307 308 static int 309 differ_by_repeat(time_t t1, time_t t0) 310 { 311 if (TYPE_BIT(time_t) - 1 < SECSPERREPEAT_BITS) 312 return 0; 313 return (int64_t)t1 - t0 == SECSPERREPEAT; 314 } 315 316 static int 317 tzload(const char *name, struct state *sp, int doextend) 318 { 319 const char * p; 320 int i; 321 int fid; 322 int stored; 323 int nread; 324 typedef union { 325 struct tzhead tzhead; 326 char buf[2 * sizeof(struct tzhead) + 327 2 * sizeof *sp + 328 4 * TZ_MAX_TIMES]; 329 } u_t; 330 u_t * up; 331 char fullname[PATH_MAX]; 332 333 up = calloc(1, sizeof *up); 334 if (up == NULL) 335 return -1; 336 337 sp->goback = sp->goahead = FALSE; 338 if (name != NULL && issetugid() != 0) { 339 if ((name[0] == ':' && (strchr(name, '/') || strstr(name, ".."))) || 340 name[0] == '/' || strchr(name, '.')) 341 name = NULL; 342 } 343 if (name == NULL && (name = TZDEFAULT) == NULL) 344 goto oops; 345 346 if (name[0] == ':') 347 ++name; 348 if (name[0] != '/') { 349 if ((p = TZDIR) == NULL) 350 goto oops; 351 if ((strlen(p) + strlen(name) + 1) >= sizeof fullname) 352 goto oops; 353 strlcpy(fullname, p, sizeof fullname); 354 strlcat(fullname, "/", sizeof fullname); 355 strlcat(fullname, name, sizeof fullname); 356 name = fullname; 357 } 358 if ((fid = open(name, O_RDONLY)) == -1) 359 goto oops; 360 361 nread = read(fid, up->buf, sizeof up->buf); 362 if (close(fid) < 0 || nread <= 0) 363 goto oops; 364 for (stored = 4; stored <= 8; stored *= 2) { 365 int ttisstdcnt; 366 int ttisgmtcnt; 367 368 ttisstdcnt = (int) detzcode(up->tzhead.tzh_ttisstdcnt); 369 ttisgmtcnt = (int) detzcode(up->tzhead.tzh_ttisgmtcnt); 370 sp->leapcnt = (int) detzcode(up->tzhead.tzh_leapcnt); 371 sp->timecnt = (int) detzcode(up->tzhead.tzh_timecnt); 372 sp->typecnt = (int) detzcode(up->tzhead.tzh_typecnt); 373 sp->charcnt = (int) detzcode(up->tzhead.tzh_charcnt); 374 p = up->tzhead.tzh_charcnt + sizeof up->tzhead.tzh_charcnt; 375 if (sp->leapcnt < 0 || sp->leapcnt > TZ_MAX_LEAPS || 376 sp->typecnt <= 0 || sp->typecnt > TZ_MAX_TYPES || 377 sp->timecnt < 0 || sp->timecnt > TZ_MAX_TIMES || 378 sp->charcnt < 0 || sp->charcnt > TZ_MAX_CHARS || 379 (ttisstdcnt != sp->typecnt && ttisstdcnt != 0) || 380 (ttisgmtcnt != sp->typecnt && ttisgmtcnt != 0)) 381 goto oops; 382 if (nread - (p - up->buf) < 383 sp->timecnt * stored + /* ats */ 384 sp->timecnt + /* types */ 385 sp->typecnt * 6 + /* ttinfos */ 386 sp->charcnt + /* chars */ 387 sp->leapcnt * (stored + 4) + /* lsinfos */ 388 ttisstdcnt + /* ttisstds */ 389 ttisgmtcnt) /* ttisgmts */ 390 goto oops; 391 for (i = 0; i < sp->timecnt; ++i) { 392 sp->ats[i] = (stored == 4) ? 393 detzcode(p) : detzcode64(p); 394 p += stored; 395 } 396 for (i = 0; i < sp->timecnt; ++i) { 397 sp->types[i] = (unsigned char) *p++; 398 if (sp->types[i] >= sp->typecnt) 399 goto oops; 400 } 401 for (i = 0; i < sp->typecnt; ++i) { 402 struct ttinfo * ttisp; 403 404 ttisp = &sp->ttis[i]; 405 ttisp->tt_gmtoff = detzcode(p); 406 p += 4; 407 ttisp->tt_isdst = (unsigned char) *p++; 408 if (ttisp->tt_isdst != 0 && ttisp->tt_isdst != 1) 409 goto oops; 410 ttisp->tt_abbrind = (unsigned char) *p++; 411 if (ttisp->tt_abbrind < 0 || 412 ttisp->tt_abbrind > sp->charcnt) 413 goto oops; 414 } 415 for (i = 0; i < sp->charcnt; ++i) 416 sp->chars[i] = *p++; 417 sp->chars[i] = '\0'; /* ensure '\0' at end */ 418 for (i = 0; i < sp->leapcnt; ++i) { 419 struct lsinfo * lsisp; 420 421 lsisp = &sp->lsis[i]; 422 lsisp->ls_trans = (stored == 4) ? 423 detzcode(p) : detzcode64(p); 424 p += stored; 425 lsisp->ls_corr = detzcode(p); 426 p += 4; 427 } 428 for (i = 0; i < sp->typecnt; ++i) { 429 struct ttinfo * ttisp; 430 431 ttisp = &sp->ttis[i]; 432 if (ttisstdcnt == 0) 433 ttisp->tt_ttisstd = FALSE; 434 else { 435 ttisp->tt_ttisstd = *p++; 436 if (ttisp->tt_ttisstd != TRUE && 437 ttisp->tt_ttisstd != FALSE) 438 goto oops; 439 } 440 } 441 for (i = 0; i < sp->typecnt; ++i) { 442 struct ttinfo * ttisp; 443 444 ttisp = &sp->ttis[i]; 445 if (ttisgmtcnt == 0) 446 ttisp->tt_ttisgmt = FALSE; 447 else { 448 ttisp->tt_ttisgmt = *p++; 449 if (ttisp->tt_ttisgmt != TRUE && 450 ttisp->tt_ttisgmt != FALSE) 451 goto oops; 452 } 453 } 454 /* 455 ** Out-of-sort ats should mean we're running on a 456 ** signed time_t system but using a data file with 457 ** unsigned values (or vice versa). 458 */ 459 for (i = 0; i < sp->timecnt - 2; ++i) 460 if (sp->ats[i] > sp->ats[i + 1]) { 461 ++i; 462 /* 463 ** Ignore the end (easy). 464 */ 465 sp->timecnt = i; 466 break; 467 } 468 /* 469 ** If this is an old file, we're done. 470 */ 471 if (up->tzhead.tzh_version[0] == '\0') 472 break; 473 nread -= p - up->buf; 474 for (i = 0; i < nread; ++i) 475 up->buf[i] = p[i]; 476 /* 477 ** If this is a narrow integer time_t system, we're done. 478 */ 479 if (stored >= sizeof(time_t)) 480 break; 481 } 482 if (doextend && nread > 2 && 483 up->buf[0] == '\n' && up->buf[nread - 1] == '\n' && 484 sp->typecnt + 2 <= TZ_MAX_TYPES) { 485 struct state ts; 486 int result; 487 488 up->buf[nread - 1] = '\0'; 489 result = tzparse(&up->buf[1], &ts, FALSE); 490 if (result == 0 && ts.typecnt == 2 && 491 sp->charcnt + ts.charcnt <= TZ_MAX_CHARS) { 492 for (i = 0; i < 2; ++i) 493 ts.ttis[i].tt_abbrind += 494 sp->charcnt; 495 for (i = 0; i < ts.charcnt; ++i) 496 sp->chars[sp->charcnt++] = 497 ts.chars[i]; 498 i = 0; 499 while (i < ts.timecnt && 500 ts.ats[i] <= 501 sp->ats[sp->timecnt - 1]) 502 ++i; 503 while (i < ts.timecnt && 504 sp->timecnt < TZ_MAX_TIMES) { 505 sp->ats[sp->timecnt] = 506 ts.ats[i]; 507 sp->types[sp->timecnt] = 508 sp->typecnt + 509 ts.types[i]; 510 ++sp->timecnt; 511 ++i; 512 } 513 sp->ttis[sp->typecnt++] = ts.ttis[0]; 514 sp->ttis[sp->typecnt++] = ts.ttis[1]; 515 } 516 } 517 if (sp->timecnt > 1) { 518 for (i = 1; i < sp->timecnt; ++i) { 519 if (typesequiv(sp, sp->types[i], sp->types[0]) && 520 differ_by_repeat(sp->ats[i], sp->ats[0])) { 521 sp->goback = TRUE; 522 break; 523 } 524 } 525 for (i = sp->timecnt - 2; i >= 0; --i) { 526 if (typesequiv(sp, sp->types[sp->timecnt - 1], 527 sp->types[i]) && 528 differ_by_repeat(sp->ats[sp->timecnt - 1], 529 sp->ats[i])) { 530 sp->goahead = TRUE; 531 break; 532 } 533 } 534 } 535 free(up); 536 return 0; 537 oops: 538 free(up); 539 return -1; 540 } 541 542 static int 543 typesequiv(const struct state *sp, int a, int b) 544 { 545 int result; 546 547 if (sp == NULL || 548 a < 0 || a >= sp->typecnt || 549 b < 0 || b >= sp->typecnt) 550 result = FALSE; 551 else { 552 const struct ttinfo * ap = &sp->ttis[a]; 553 const struct ttinfo * bp = &sp->ttis[b]; 554 result = ap->tt_gmtoff == bp->tt_gmtoff && 555 ap->tt_isdst == bp->tt_isdst && 556 ap->tt_ttisstd == bp->tt_ttisstd && 557 ap->tt_ttisgmt == bp->tt_ttisgmt && 558 strcmp(&sp->chars[ap->tt_abbrind], 559 &sp->chars[bp->tt_abbrind]) == 0; 560 } 561 return result; 562 } 563 564 static const int mon_lengths[2][MONSPERYEAR] = { 565 { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }, 566 { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 } 567 }; 568 569 static const int year_lengths[2] = { 570 DAYSPERNYEAR, DAYSPERLYEAR 571 }; 572 573 /* 574 ** Given a pointer into a time zone string, scan until a character that is not 575 ** a valid character in a zone name is found. Return a pointer to that 576 ** character. 577 */ 578 579 static const char * 580 getzname(const char *strp) 581 { 582 char c; 583 584 while ((c = *strp) != '\0' && !isdigit((unsigned char)c) && c != ',' && c != '-' && 585 c != '+') 586 ++strp; 587 return strp; 588 } 589 590 /* 591 ** Given a pointer into an extended time zone string, scan until the ending 592 ** delimiter of the zone name is located. Return a pointer to the delimiter. 593 ** 594 ** As with getzname above, the legal character set is actually quite 595 ** restricted, with other characters producing undefined results. 596 ** We don't do any checking here; checking is done later in common-case code. 597 */ 598 599 static const char * 600 getqzname(const char *strp, const int delim) 601 { 602 int c; 603 604 while ((c = *strp) != '\0' && c != delim) 605 ++strp; 606 return strp; 607 } 608 609 /* 610 ** Given a pointer into a time zone string, extract a number from that string. 611 ** Check that the number is within a specified range; if it is not, return 612 ** NULL. 613 ** Otherwise, return a pointer to the first character not part of the number. 614 */ 615 616 static const char * 617 getnum(const char *strp, int *nump, int min, int max) 618 { 619 char c; 620 int num; 621 622 if (strp == NULL || !isdigit((unsigned char)(c = *strp))) 623 return NULL; 624 num = 0; 625 do { 626 num = num * 10 + (c - '0'); 627 if (num > max) 628 return NULL; /* illegal value */ 629 c = *++strp; 630 } while (isdigit((unsigned char)c)); 631 if (num < min) 632 return NULL; /* illegal value */ 633 *nump = num; 634 return strp; 635 } 636 637 /* 638 ** Given a pointer into a time zone string, extract a number of seconds, 639 ** in hh[:mm[:ss]] form, from the string. 640 ** If any error occurs, return NULL. 641 ** Otherwise, return a pointer to the first character not part of the number 642 ** of seconds. 643 */ 644 645 static const char * 646 getsecs(const char *strp, long *secsp) 647 { 648 int num; 649 650 /* 651 ** `HOURSPERDAY * DAYSPERWEEK - 1' allows quasi-Posix rules like 652 ** "M10.4.6/26", which does not conform to Posix, 653 ** but which specifies the equivalent of 654 ** ``02:00 on the first Sunday on or after 23 Oct''. 655 */ 656 strp = getnum(strp, &num, 0, HOURSPERDAY * DAYSPERWEEK - 1); 657 if (strp == NULL) 658 return NULL; 659 *secsp = num * (long) SECSPERHOUR; 660 if (*strp == ':') { 661 ++strp; 662 strp = getnum(strp, &num, 0, MINSPERHOUR - 1); 663 if (strp == NULL) 664 return NULL; 665 *secsp += num * SECSPERMIN; 666 if (*strp == ':') { 667 ++strp; 668 /* `SECSPERMIN' allows for leap seconds. */ 669 strp = getnum(strp, &num, 0, SECSPERMIN); 670 if (strp == NULL) 671 return NULL; 672 *secsp += num; 673 } 674 } 675 return strp; 676 } 677 678 /* 679 ** Given a pointer into a time zone string, extract an offset, in 680 ** [+-]hh[:mm[:ss]] form, from the string. 681 ** If any error occurs, return NULL. 682 ** Otherwise, return a pointer to the first character not part of the time. 683 */ 684 685 static const char * 686 getoffset(const char *strp, long *offsetp) 687 { 688 int neg = 0; 689 690 if (*strp == '-') { 691 neg = 1; 692 ++strp; 693 } else if (*strp == '+') 694 ++strp; 695 strp = getsecs(strp, offsetp); 696 if (strp == NULL) 697 return NULL; /* illegal time */ 698 if (neg) 699 *offsetp = -*offsetp; 700 return strp; 701 } 702 703 /* 704 ** Given a pointer into a time zone string, extract a rule in the form 705 ** date[/time]. See POSIX section 8 for the format of "date" and "time". 706 ** If a valid rule is not found, return NULL. 707 ** Otherwise, return a pointer to the first character not part of the rule. 708 */ 709 710 static const char * 711 getrule(const char *strp, struct rule *rulep) 712 { 713 if (*strp == 'J') { 714 /* 715 ** Julian day. 716 */ 717 rulep->r_type = JULIAN_DAY; 718 ++strp; 719 strp = getnum(strp, &rulep->r_day, 1, DAYSPERNYEAR); 720 } else if (*strp == 'M') { 721 /* 722 ** Month, week, day. 723 */ 724 rulep->r_type = MONTH_NTH_DAY_OF_WEEK; 725 ++strp; 726 strp = getnum(strp, &rulep->r_mon, 1, MONSPERYEAR); 727 if (strp == NULL) 728 return NULL; 729 if (*strp++ != '.') 730 return NULL; 731 strp = getnum(strp, &rulep->r_week, 1, 5); 732 if (strp == NULL) 733 return NULL; 734 if (*strp++ != '.') 735 return NULL; 736 strp = getnum(strp, &rulep->r_day, 0, DAYSPERWEEK - 1); 737 } else if (isdigit((unsigned char)*strp)) { 738 /* 739 ** Day of year. 740 */ 741 rulep->r_type = DAY_OF_YEAR; 742 strp = getnum(strp, &rulep->r_day, 0, DAYSPERLYEAR - 1); 743 } else 744 return NULL; /* invalid format */ 745 if (strp == NULL) 746 return NULL; 747 if (*strp == '/') { 748 /* 749 ** Time specified. 750 */ 751 ++strp; 752 strp = getsecs(strp, &rulep->r_time); 753 } else 754 rulep->r_time = 2 * SECSPERHOUR; /* default = 2:00:00 */ 755 return strp; 756 } 757 758 /* 759 ** Given the Epoch-relative time of January 1, 00:00:00 UTC, in a year, the 760 ** year, a rule, and the offset from UTC at the time that rule takes effect, 761 ** calculate the Epoch-relative time that rule takes effect. 762 */ 763 764 static time_t 765 transtime(time_t janfirst, int year, const struct rule *rulep, long offset) 766 { 767 int leapyear; 768 time_t value; 769 int i; 770 int d, m1, yy0, yy1, yy2, dow; 771 772 value = 0; 773 leapyear = isleap(year); 774 switch (rulep->r_type) { 775 776 case JULIAN_DAY: 777 /* 778 ** Jn - Julian day, 1 == January 1, 60 == March 1 even in leap 779 ** years. 780 ** In non-leap years, or if the day number is 59 or less, just 781 ** add SECSPERDAY times the day number-1 to the time of 782 ** January 1, midnight, to get the day. 783 */ 784 value = janfirst + (rulep->r_day - 1) * SECSPERDAY; 785 if (leapyear && rulep->r_day >= 60) 786 value += SECSPERDAY; 787 break; 788 789 case DAY_OF_YEAR: 790 /* 791 ** n - day of year. 792 ** Just add SECSPERDAY times the day number to the time of 793 ** January 1, midnight, to get the day. 794 */ 795 value = janfirst + rulep->r_day * SECSPERDAY; 796 break; 797 798 case MONTH_NTH_DAY_OF_WEEK: 799 /* 800 ** Mm.n.d - nth "dth day" of month m. 801 */ 802 value = janfirst; 803 for (i = 0; i < rulep->r_mon - 1; ++i) 804 value += mon_lengths[leapyear][i] * SECSPERDAY; 805 806 /* 807 ** Use Zeller's Congruence to get day-of-week of first day of 808 ** month. 809 */ 810 m1 = (rulep->r_mon + 9) % 12 + 1; 811 yy0 = (rulep->r_mon <= 2) ? (year - 1) : year; 812 yy1 = yy0 / 100; 813 yy2 = yy0 % 100; 814 dow = ((26 * m1 - 2) / 10 + 815 1 + yy2 + yy2 / 4 + yy1 / 4 - 2 * yy1) % 7; 816 if (dow < 0) 817 dow += DAYSPERWEEK; 818 819 /* 820 ** "dow" is the day-of-week of the first day of the month. Get 821 ** the day-of-month (zero-origin) of the first "dow" day of the 822 ** month. 823 */ 824 d = rulep->r_day - dow; 825 if (d < 0) 826 d += DAYSPERWEEK; 827 for (i = 1; i < rulep->r_week; ++i) { 828 if (d + DAYSPERWEEK >= 829 mon_lengths[leapyear][rulep->r_mon - 1]) 830 break; 831 d += DAYSPERWEEK; 832 } 833 834 /* 835 ** "d" is the day-of-month (zero-origin) of the day we want. 836 */ 837 value += d * SECSPERDAY; 838 break; 839 } 840 841 /* 842 ** "value" is the Epoch-relative time of 00:00:00 UTC on the day in 843 ** question. To get the Epoch-relative time of the specified local 844 ** time on that day, add the transition time and the current offset 845 ** from UTC. 846 */ 847 return value + rulep->r_time + offset; 848 } 849 850 /* 851 ** Given a POSIX section 8-style TZ string, fill in the rule tables as 852 ** appropriate. 853 */ 854 855 static int 856 tzparse(const char *name, struct state *sp, int lastditch) 857 { 858 const char * stdname; 859 const char * dstname; 860 size_t stdlen; 861 size_t dstlen; 862 long stdoffset; 863 long dstoffset; 864 time_t * atp; 865 unsigned char * typep; 866 char * cp; 867 int load_result; 868 static struct ttinfo zttinfo; 869 870 dstname = NULL; 871 stdname = name; 872 if (lastditch) { 873 stdlen = strlen(name); /* length of standard zone name */ 874 name += stdlen; 875 if (stdlen >= sizeof sp->chars) 876 stdlen = (sizeof sp->chars) - 1; 877 stdoffset = 0; 878 } else { 879 if (*name == '<') { 880 name++; 881 stdname = name; 882 name = getqzname(name, '>'); 883 if (*name != '>') 884 return (-1); 885 stdlen = name - stdname; 886 name++; 887 } else { 888 name = getzname(name); 889 stdlen = name - stdname; 890 } 891 if (*name == '\0') 892 return -1; 893 name = getoffset(name, &stdoffset); 894 if (name == NULL) 895 return -1; 896 } 897 load_result = tzload(TZDEFRULES, sp, FALSE); 898 if (load_result != 0) 899 sp->leapcnt = 0; /* so, we're off a little */ 900 if (*name != '\0') { 901 if (*name == '<') { 902 dstname = ++name; 903 name = getqzname(name, '>'); 904 if (*name != '>') 905 return -1; 906 dstlen = name - dstname; 907 name++; 908 } else { 909 dstname = name; 910 name = getzname(name); 911 dstlen = name - dstname; /* length of DST zone name */ 912 } 913 if (*name != '\0' && *name != ',' && *name != ';') { 914 name = getoffset(name, &dstoffset); 915 if (name == NULL) 916 return -1; 917 } else 918 dstoffset = stdoffset - SECSPERHOUR; 919 if (*name == '\0' && load_result != 0) 920 name = TZDEFRULESTRING; 921 if (*name == ',' || *name == ';') { 922 struct rule start; 923 struct rule end; 924 int year; 925 time_t janfirst; 926 time_t starttime; 927 time_t endtime; 928 929 ++name; 930 if ((name = getrule(name, &start)) == NULL) 931 return -1; 932 if (*name++ != ',') 933 return -1; 934 if ((name = getrule(name, &end)) == NULL) 935 return -1; 936 if (*name != '\0') 937 return -1; 938 sp->typecnt = 2; /* standard time and DST */ 939 /* 940 ** Two transitions per year, from EPOCH_YEAR forward. 941 */ 942 sp->ttis[0] = sp->ttis[1] = zttinfo; 943 sp->ttis[0].tt_gmtoff = -dstoffset; 944 sp->ttis[0].tt_isdst = 1; 945 sp->ttis[0].tt_abbrind = stdlen + 1; 946 sp->ttis[1].tt_gmtoff = -stdoffset; 947 sp->ttis[1].tt_isdst = 0; 948 sp->ttis[1].tt_abbrind = 0; 949 atp = sp->ats; 950 typep = sp->types; 951 janfirst = 0; 952 sp->timecnt = 0; 953 for (year = EPOCH_YEAR; 954 sp->timecnt + 2 <= TZ_MAX_TIMES; 955 ++year) { 956 time_t newfirst; 957 958 starttime = transtime(janfirst, year, &start, 959 stdoffset); 960 endtime = transtime(janfirst, year, &end, 961 dstoffset); 962 if (starttime > endtime) { 963 *atp++ = endtime; 964 *typep++ = 1; /* DST ends */ 965 *atp++ = starttime; 966 *typep++ = 0; /* DST begins */ 967 } else { 968 *atp++ = starttime; 969 *typep++ = 0; /* DST begins */ 970 *atp++ = endtime; 971 *typep++ = 1; /* DST ends */ 972 } 973 sp->timecnt += 2; 974 newfirst = janfirst; 975 newfirst += year_lengths[isleap(year)] * 976 SECSPERDAY; 977 if (newfirst <= janfirst) 978 break; 979 janfirst = newfirst; 980 } 981 } else { 982 long theirstdoffset; 983 long theirdstoffset; 984 long theiroffset; 985 int isdst; 986 int i; 987 int j; 988 989 if (*name != '\0') 990 return -1; 991 /* 992 ** Initial values of theirstdoffset and theirdstoffset. 993 */ 994 theirstdoffset = 0; 995 for (i = 0; i < sp->timecnt; ++i) { 996 j = sp->types[i]; 997 if (!sp->ttis[j].tt_isdst) { 998 theirstdoffset = 999 -sp->ttis[j].tt_gmtoff; 1000 break; 1001 } 1002 } 1003 theirdstoffset = 0; 1004 for (i = 0; i < sp->timecnt; ++i) { 1005 j = sp->types[i]; 1006 if (sp->ttis[j].tt_isdst) { 1007 theirdstoffset = 1008 -sp->ttis[j].tt_gmtoff; 1009 break; 1010 } 1011 } 1012 /* 1013 ** Initially we're assumed to be in standard time. 1014 */ 1015 isdst = FALSE; 1016 theiroffset = theirstdoffset; 1017 /* 1018 ** Now juggle transition times and types 1019 ** tracking offsets as you do. 1020 */ 1021 for (i = 0; i < sp->timecnt; ++i) { 1022 j = sp->types[i]; 1023 sp->types[i] = sp->ttis[j].tt_isdst; 1024 if (sp->ttis[j].tt_ttisgmt) { 1025 /* No adjustment to transition time */ 1026 } else { 1027 /* 1028 ** If summer time is in effect, and the 1029 ** transition time was not specified as 1030 ** standard time, add the summer time 1031 ** offset to the transition time; 1032 ** otherwise, add the standard time 1033 ** offset to the transition time. 1034 */ 1035 /* 1036 ** Transitions from DST to DDST 1037 ** will effectively disappear since 1038 ** POSIX provides for only one DST 1039 ** offset. 1040 */ 1041 if (isdst && !sp->ttis[j].tt_ttisstd) { 1042 sp->ats[i] += dstoffset - 1043 theirdstoffset; 1044 } else { 1045 sp->ats[i] += stdoffset - 1046 theirstdoffset; 1047 } 1048 } 1049 theiroffset = -sp->ttis[j].tt_gmtoff; 1050 if (sp->ttis[j].tt_isdst) 1051 theirdstoffset = theiroffset; 1052 else 1053 theirstdoffset = theiroffset; 1054 } 1055 /* 1056 ** Finally, fill in ttis. 1057 */ 1058 sp->ttis[0] = sp->ttis[1] = zttinfo; 1059 sp->ttis[0].tt_gmtoff = -stdoffset; 1060 sp->ttis[0].tt_isdst = FALSE; 1061 sp->ttis[0].tt_abbrind = 0; 1062 sp->ttis[1].tt_gmtoff = -dstoffset; 1063 sp->ttis[1].tt_isdst = TRUE; 1064 sp->ttis[1].tt_abbrind = stdlen + 1; 1065 sp->typecnt = 2; 1066 } 1067 } else { 1068 dstlen = 0; 1069 sp->typecnt = 1; /* only standard time */ 1070 sp->timecnt = 0; 1071 sp->ttis[0] = zttinfo; 1072 sp->ttis[0].tt_gmtoff = -stdoffset; 1073 sp->ttis[0].tt_isdst = 0; 1074 sp->ttis[0].tt_abbrind = 0; 1075 } 1076 sp->charcnt = stdlen + 1; 1077 if (dstlen != 0) 1078 sp->charcnt += dstlen + 1; 1079 if ((size_t) sp->charcnt > sizeof sp->chars) 1080 return -1; 1081 cp = sp->chars; 1082 strlcpy(cp, stdname, stdlen + 1); 1083 cp += stdlen + 1; 1084 if (dstlen != 0) { 1085 strlcpy(cp, dstname, dstlen + 1); 1086 } 1087 return 0; 1088 } 1089 1090 static void 1091 gmtload(struct state *sp) 1092 { 1093 if (tzload(gmt, sp, TRUE) != 0) 1094 (void) tzparse(gmt, sp, TRUE); 1095 } 1096 1097 static void 1098 tzsetwall_basic(void) 1099 { 1100 if (lcl_is_set < 0) 1101 return; 1102 lcl_is_set = -1; 1103 1104 if (lclptr == NULL) { 1105 lclptr = calloc(1, sizeof *lclptr); 1106 if (lclptr == NULL) { 1107 settzname(); /* all we can do */ 1108 return; 1109 } 1110 } 1111 if (tzload(NULL, lclptr, TRUE) != 0) 1112 gmtload(lclptr); 1113 settzname(); 1114 } 1115 1116 #ifndef STD_INSPIRED 1117 /* 1118 ** A non-static declaration of tzsetwall in a system header file 1119 ** may cause a warning about this upcoming static declaration... 1120 */ 1121 static 1122 #endif /* !defined STD_INSPIRED */ 1123 void 1124 tzsetwall(void) 1125 { 1126 _THREAD_PRIVATE_MUTEX_LOCK(lcl); 1127 tzsetwall_basic(); 1128 _THREAD_PRIVATE_MUTEX_UNLOCK(lcl); 1129 } 1130 1131 static void 1132 tzset_basic(void) 1133 { 1134 const char * name; 1135 1136 name = getenv("TZ"); 1137 if (name == NULL) { 1138 tzsetwall_basic(); 1139 return; 1140 } 1141 1142 if (lcl_is_set > 0 && strcmp(lcl_TZname, name) == 0) 1143 return; 1144 lcl_is_set = strlen(name) < sizeof lcl_TZname; 1145 if (lcl_is_set) 1146 strlcpy(lcl_TZname, name, sizeof lcl_TZname); 1147 1148 if (lclptr == NULL) { 1149 lclptr = calloc(1, sizeof *lclptr); 1150 if (lclptr == NULL) { 1151 settzname(); /* all we can do */ 1152 return; 1153 } 1154 } 1155 if (*name == '\0') { 1156 /* 1157 ** User wants it fast rather than right. 1158 */ 1159 lclptr->leapcnt = 0; /* so, we're off a little */ 1160 lclptr->timecnt = 0; 1161 lclptr->typecnt = 0; 1162 lclptr->ttis[0].tt_isdst = 0; 1163 lclptr->ttis[0].tt_gmtoff = 0; 1164 lclptr->ttis[0].tt_abbrind = 0; 1165 strlcpy(lclptr->chars, gmt, sizeof lclptr->chars); 1166 } else if (tzload(name, lclptr, TRUE) != 0) { 1167 if (name[0] == ':' || tzparse(name, lclptr, FALSE) != 0) 1168 gmtload(lclptr); 1169 } 1170 settzname(); 1171 } 1172 1173 void 1174 tzset(void) 1175 { 1176 _THREAD_PRIVATE_MUTEX_LOCK(lcl); 1177 tzset_basic(); 1178 _THREAD_PRIVATE_MUTEX_UNLOCK(lcl); 1179 } 1180 DEF_WEAK(tzset); 1181 1182 /* 1183 ** The easy way to behave "as if no library function calls" localtime 1184 ** is to not call it--so we drop its guts into "localsub", which can be 1185 ** freely called. (And no, the PANS doesn't require the above behavior-- 1186 ** but it *is* desirable.) 1187 ** 1188 ** The unused offset argument is for the benefit of mktime variants. 1189 */ 1190 1191 static struct tm * 1192 localsub(const time_t *timep, long offset, struct tm *tmp) 1193 { 1194 struct state * sp; 1195 const struct ttinfo * ttisp; 1196 int i; 1197 struct tm * result; 1198 const time_t t = *timep; 1199 1200 sp = lclptr; 1201 if (sp == NULL) 1202 return gmtsub(timep, offset, tmp); 1203 if ((sp->goback && t < sp->ats[0]) || 1204 (sp->goahead && t > sp->ats[sp->timecnt - 1])) { 1205 time_t newt = t; 1206 time_t seconds; 1207 time_t tcycles; 1208 int_fast64_t icycles; 1209 1210 if (t < sp->ats[0]) 1211 seconds = sp->ats[0] - t; 1212 else 1213 seconds = t - sp->ats[sp->timecnt - 1]; 1214 --seconds; 1215 tcycles = seconds / YEARSPERREPEAT / AVGSECSPERYEAR; 1216 ++tcycles; 1217 icycles = tcycles; 1218 if (tcycles - icycles >= 1 || icycles - tcycles >= 1) 1219 return NULL; 1220 seconds = icycles; 1221 seconds *= YEARSPERREPEAT; 1222 seconds *= AVGSECSPERYEAR; 1223 if (t < sp->ats[0]) 1224 newt += seconds; 1225 else 1226 newt -= seconds; 1227 if (newt < sp->ats[0] || 1228 newt > sp->ats[sp->timecnt - 1]) 1229 return NULL; /* "cannot happen" */ 1230 result = localsub(&newt, offset, tmp); 1231 if (result == tmp) { 1232 time_t newy; 1233 1234 newy = tmp->tm_year; 1235 if (t < sp->ats[0]) 1236 newy -= icycles * YEARSPERREPEAT; 1237 else 1238 newy += icycles * YEARSPERREPEAT; 1239 tmp->tm_year = newy; 1240 if (tmp->tm_year != newy) 1241 return NULL; 1242 } 1243 return result; 1244 } 1245 if (sp->timecnt == 0 || t < sp->ats[0]) { 1246 i = 0; 1247 while (sp->ttis[i].tt_isdst) { 1248 if (++i >= sp->typecnt) { 1249 i = 0; 1250 break; 1251 } 1252 } 1253 } else { 1254 int lo = 1; 1255 int hi = sp->timecnt; 1256 1257 while (lo < hi) { 1258 int mid = (lo + hi) >> 1; 1259 1260 if (t < sp->ats[mid]) 1261 hi = mid; 1262 else 1263 lo = mid + 1; 1264 } 1265 i = (int) sp->types[lo - 1]; 1266 } 1267 ttisp = &sp->ttis[i]; 1268 /* 1269 ** To get (wrong) behavior that's compatible with System V Release 2.0 1270 ** you'd replace the statement below with 1271 ** t += ttisp->tt_gmtoff; 1272 ** timesub(&t, 0L, sp, tmp); 1273 */ 1274 result = timesub(&t, ttisp->tt_gmtoff, sp, tmp); 1275 tmp->tm_isdst = ttisp->tt_isdst; 1276 tzname[tmp->tm_isdst] = &sp->chars[ttisp->tt_abbrind]; 1277 #ifdef TM_ZONE 1278 tmp->TM_ZONE = &sp->chars[ttisp->tt_abbrind]; 1279 #endif /* defined TM_ZONE */ 1280 return result; 1281 } 1282 1283 /* 1284 ** Re-entrant version of localtime. 1285 */ 1286 1287 struct tm * 1288 localtime_r(const time_t *timep, struct tm *p_tm) 1289 { 1290 _THREAD_PRIVATE_MUTEX_LOCK(lcl); 1291 tzset_basic(); 1292 p_tm = localsub(timep, 0L, p_tm); 1293 _THREAD_PRIVATE_MUTEX_UNLOCK(lcl); 1294 return p_tm; 1295 } 1296 DEF_WEAK(localtime_r); 1297 1298 struct tm * 1299 localtime(const time_t *timep) 1300 { 1301 _THREAD_PRIVATE_KEY(localtime); 1302 struct tm * p_tm = (struct tm*)_THREAD_PRIVATE(localtime, tm, NULL); 1303 1304 if (p_tm == NULL) 1305 return NULL; 1306 return localtime_r(timep, p_tm); 1307 } 1308 DEF_STRONG(localtime); 1309 1310 /* 1311 ** gmtsub is to gmtime as localsub is to localtime. 1312 */ 1313 1314 static struct tm * 1315 gmtsub(const time_t *timep, long offset, struct tm *tmp) 1316 { 1317 struct tm * result; 1318 1319 _THREAD_PRIVATE_MUTEX_LOCK(gmt); 1320 if (!gmt_is_set) { 1321 gmt_is_set = TRUE; 1322 gmtptr = calloc(1, sizeof(*gmtptr)); 1323 if (gmtptr != NULL) 1324 gmtload(gmtptr); 1325 } 1326 _THREAD_PRIVATE_MUTEX_UNLOCK(gmt); 1327 result = timesub(timep, offset, gmtptr, tmp); 1328 #ifdef TM_ZONE 1329 /* 1330 ** Could get fancy here and deliver something such as 1331 ** "UTC+xxxx" or "UTC-xxxx" if offset is non-zero, 1332 ** but this is no time for a treasure hunt. 1333 */ 1334 if (offset != 0) 1335 tmp->TM_ZONE = wildabbr; 1336 else { 1337 if (gmtptr == NULL) 1338 tmp->TM_ZONE = (char *)gmt; 1339 else 1340 tmp->TM_ZONE = gmtptr->chars; 1341 } 1342 #endif /* defined TM_ZONE */ 1343 return result; 1344 } 1345 1346 /* 1347 ** Re-entrant version of gmtime. 1348 */ 1349 1350 struct tm * 1351 gmtime_r(const time_t *timep, struct tm *p_tm) 1352 { 1353 return gmtsub(timep, 0L, p_tm); 1354 } 1355 DEF_WEAK(gmtime_r); 1356 1357 struct tm * 1358 gmtime(const time_t *timep) 1359 { 1360 _THREAD_PRIVATE_KEY(gmtime); 1361 struct tm * p_tm = (struct tm*) _THREAD_PRIVATE(gmtime, tm, NULL); 1362 1363 if (p_tm == NULL) 1364 return NULL; 1365 return gmtime_r(timep, p_tm); 1366 1367 } 1368 DEF_WEAK(gmtime); 1369 1370 #ifdef STD_INSPIRED 1371 1372 struct tm * 1373 offtime(const time_t *timep, long offset) 1374 { 1375 return gmtsub(timep, offset, &tm); 1376 } 1377 1378 #endif /* defined STD_INSPIRED */ 1379 1380 /* 1381 ** Return the number of leap years through the end of the given year 1382 ** where, to make the math easy, the answer for year zero is defined as zero. 1383 */ 1384 1385 static int 1386 leaps_thru_end_of(int y) 1387 { 1388 return (y >= 0) ? (y / 4 - y / 100 + y / 400) : 1389 -(leaps_thru_end_of(-(y + 1)) + 1); 1390 } 1391 1392 static struct tm * 1393 timesub(const time_t *timep, long offset, const struct state *sp, struct tm *tmp) 1394 { 1395 const struct lsinfo * lp; 1396 time_t tdays; 1397 int idays; /* unsigned would be so 2003 */ 1398 long rem; 1399 int y; 1400 const int * ip; 1401 long corr; 1402 int hit; 1403 int i; 1404 long seconds; 1405 1406 corr = 0; 1407 hit = 0; 1408 i = (sp == NULL) ? 0 : sp->leapcnt; 1409 while (--i >= 0) { 1410 lp = &sp->lsis[i]; 1411 if (*timep >= lp->ls_trans) { 1412 if (*timep == lp->ls_trans) { 1413 hit = ((i == 0 && lp->ls_corr > 0) || 1414 lp->ls_corr > sp->lsis[i - 1].ls_corr); 1415 if (hit) { 1416 while (i > 0 && 1417 sp->lsis[i].ls_trans == 1418 sp->lsis[i - 1].ls_trans + 1 && 1419 sp->lsis[i].ls_corr == 1420 sp->lsis[i - 1].ls_corr + 1) { 1421 ++hit; 1422 --i; 1423 } 1424 } 1425 } 1426 corr = lp->ls_corr; 1427 break; 1428 } 1429 } 1430 y = EPOCH_YEAR; 1431 tdays = *timep / SECSPERDAY; 1432 rem = *timep - tdays * SECSPERDAY; 1433 while (tdays < 0 || tdays >= year_lengths[isleap(y)]) { 1434 int newy; 1435 time_t tdelta; 1436 int idelta; 1437 int leapdays; 1438 1439 tdelta = tdays / DAYSPERLYEAR; 1440 idelta = tdelta; 1441 if (tdelta - idelta >= 1 || idelta - tdelta >= 1) 1442 return NULL; 1443 if (idelta == 0) 1444 idelta = (tdays < 0) ? -1 : 1; 1445 newy = y; 1446 if (increment_overflow(&newy, idelta)) 1447 return NULL; 1448 leapdays = leaps_thru_end_of(newy - 1) - 1449 leaps_thru_end_of(y - 1); 1450 tdays -= ((time_t) newy - y) * DAYSPERNYEAR; 1451 tdays -= leapdays; 1452 y = newy; 1453 } 1454 1455 seconds = tdays * SECSPERDAY + 0.5; 1456 tdays = seconds / SECSPERDAY; 1457 rem += seconds - tdays * SECSPERDAY; 1458 1459 /* 1460 ** Given the range, we can now fearlessly cast... 1461 */ 1462 idays = tdays; 1463 rem += offset - corr; 1464 while (rem < 0) { 1465 rem += SECSPERDAY; 1466 --idays; 1467 } 1468 while (rem >= SECSPERDAY) { 1469 rem -= SECSPERDAY; 1470 ++idays; 1471 } 1472 while (idays < 0) { 1473 if (increment_overflow(&y, -1)) 1474 return NULL; 1475 idays += year_lengths[isleap(y)]; 1476 } 1477 while (idays >= year_lengths[isleap(y)]) { 1478 idays -= year_lengths[isleap(y)]; 1479 if (increment_overflow(&y, 1)) 1480 return NULL; 1481 } 1482 tmp->tm_year = y; 1483 if (increment_overflow(&tmp->tm_year, -TM_YEAR_BASE)) 1484 return NULL; 1485 tmp->tm_yday = idays; 1486 /* 1487 ** The "extra" mods below avoid overflow problems. 1488 */ 1489 tmp->tm_wday = EPOCH_WDAY + 1490 ((y - EPOCH_YEAR) % DAYSPERWEEK) * 1491 (DAYSPERNYEAR % DAYSPERWEEK) + 1492 leaps_thru_end_of(y - 1) - 1493 leaps_thru_end_of(EPOCH_YEAR - 1) + 1494 idays; 1495 tmp->tm_wday %= DAYSPERWEEK; 1496 if (tmp->tm_wday < 0) 1497 tmp->tm_wday += DAYSPERWEEK; 1498 tmp->tm_hour = (int) (rem / SECSPERHOUR); 1499 rem %= SECSPERHOUR; 1500 tmp->tm_min = (int) (rem / SECSPERMIN); 1501 /* 1502 ** A positive leap second requires a special 1503 ** representation. This uses "... ??:59:60" et seq. 1504 */ 1505 tmp->tm_sec = (int) (rem % SECSPERMIN) + hit; 1506 ip = mon_lengths[isleap(y)]; 1507 for (tmp->tm_mon = 0; idays >= ip[tmp->tm_mon]; ++(tmp->tm_mon)) 1508 idays -= ip[tmp->tm_mon]; 1509 tmp->tm_mday = (int) (idays + 1); 1510 tmp->tm_isdst = 0; 1511 #ifdef TM_GMTOFF 1512 tmp->TM_GMTOFF = offset; 1513 #endif /* defined TM_GMTOFF */ 1514 return tmp; 1515 } 1516 1517 char * 1518 ctime(const time_t *timep) 1519 { 1520 /* 1521 ** Section 4.12.3.2 of X3.159-1989 requires that 1522 ** The ctime function converts the calendar time pointed to by timer 1523 ** to local time in the form of a string. It is equivalent to 1524 ** asctime(localtime(timer)) 1525 */ 1526 return asctime(localtime(timep)); 1527 } 1528 1529 char * 1530 ctime_r(const time_t *timep, char *buf) 1531 { 1532 struct tm mytm; 1533 1534 return asctime_r(localtime_r(timep, &mytm), buf); 1535 } 1536 1537 /* 1538 ** Adapted from code provided by Robert Elz, who writes: 1539 ** The "best" way to do mktime I think is based on an idea of Bob 1540 ** Kridle's (so its said...) from a long time ago. 1541 ** It does a binary search of the time_t space. Since time_t's are 1542 ** just 32 bits, its a max of 32 iterations (even at 64 bits it 1543 ** would still be very reasonable). 1544 */ 1545 1546 #ifndef WRONG 1547 #define WRONG (-1) 1548 #endif /* !defined WRONG */ 1549 1550 /* 1551 ** Normalize logic courtesy Paul Eggert. 1552 */ 1553 1554 static int 1555 increment_overflow(int *ip, int j) 1556 { 1557 int const i = *ip; 1558 1559 /* 1560 ** If i >= 0 there can only be overflow if i + j > INT_MAX 1561 ** or if j > INT_MAX - i; given i >= 0, INT_MAX - i cannot overflow. 1562 ** If i < 0 there can only be overflow if i + j < INT_MIN 1563 ** or if j < INT_MIN - i; given i < 0, INT_MIN - i cannot overflow. 1564 */ 1565 if ((i >= 0) ? (j > INT_MAX - i) : (j < INT_MIN - i)) 1566 return TRUE; 1567 *ip += j; 1568 return FALSE; 1569 } 1570 1571 static int 1572 long_increment_overflow(long *lp, int m) 1573 { 1574 long const l = *lp; 1575 1576 if ((l >= 0) ? (m > LONG_MAX - l) : (m < LONG_MIN - l)) 1577 return TRUE; 1578 *lp += m; 1579 return FALSE; 1580 } 1581 1582 static int 1583 normalize_overflow(int *tensptr, int *unitsptr, int base) 1584 { 1585 int tensdelta; 1586 1587 tensdelta = (*unitsptr >= 0) ? 1588 (*unitsptr / base) : 1589 (-1 - (-1 - *unitsptr) / base); 1590 *unitsptr -= tensdelta * base; 1591 return increment_overflow(tensptr, tensdelta); 1592 } 1593 1594 static int 1595 long_normalize_overflow(long *tensptr, int *unitsptr, int base) 1596 { 1597 int tensdelta; 1598 1599 tensdelta = (*unitsptr >= 0) ? 1600 (*unitsptr / base) : 1601 (-1 - (-1 - *unitsptr) / base); 1602 *unitsptr -= tensdelta * base; 1603 return long_increment_overflow(tensptr, tensdelta); 1604 } 1605 1606 static int 1607 tmcomp(const struct tm *atmp, const struct tm *btmp) 1608 { 1609 int result; 1610 1611 if ((result = (atmp->tm_year - btmp->tm_year)) == 0 && 1612 (result = (atmp->tm_mon - btmp->tm_mon)) == 0 && 1613 (result = (atmp->tm_mday - btmp->tm_mday)) == 0 && 1614 (result = (atmp->tm_hour - btmp->tm_hour)) == 0 && 1615 (result = (atmp->tm_min - btmp->tm_min)) == 0) 1616 result = atmp->tm_sec - btmp->tm_sec; 1617 return result; 1618 } 1619 1620 static time_t 1621 time2sub(struct tm *tmp, struct tm *(*funcp)(const time_t *, long, struct tm *), 1622 long offset, int *okayp, int do_norm_secs) 1623 { 1624 const struct state * sp; 1625 int dir; 1626 int i, j; 1627 int saved_seconds; 1628 long li; 1629 time_t lo; 1630 time_t hi; 1631 long y; 1632 time_t newt; 1633 time_t t; 1634 struct tm yourtm, mytm; 1635 1636 *okayp = FALSE; 1637 yourtm = *tmp; 1638 if (do_norm_secs) { 1639 if (normalize_overflow(&yourtm.tm_min, &yourtm.tm_sec, 1640 SECSPERMIN)) 1641 return WRONG; 1642 } 1643 if (normalize_overflow(&yourtm.tm_hour, &yourtm.tm_min, MINSPERHOUR)) 1644 return WRONG; 1645 if (normalize_overflow(&yourtm.tm_mday, &yourtm.tm_hour, HOURSPERDAY)) 1646 return WRONG; 1647 y = yourtm.tm_year; 1648 if (long_normalize_overflow(&y, &yourtm.tm_mon, MONSPERYEAR)) 1649 return WRONG; 1650 /* 1651 ** Turn y into an actual year number for now. 1652 ** It is converted back to an offset from TM_YEAR_BASE later. 1653 */ 1654 if (long_increment_overflow(&y, TM_YEAR_BASE)) 1655 return WRONG; 1656 while (yourtm.tm_mday <= 0) { 1657 if (long_increment_overflow(&y, -1)) 1658 return WRONG; 1659 li = y + (1 < yourtm.tm_mon); 1660 yourtm.tm_mday += year_lengths[isleap(li)]; 1661 } 1662 while (yourtm.tm_mday > DAYSPERLYEAR) { 1663 li = y + (1 < yourtm.tm_mon); 1664 yourtm.tm_mday -= year_lengths[isleap(li)]; 1665 if (long_increment_overflow(&y, 1)) 1666 return WRONG; 1667 } 1668 for ( ; ; ) { 1669 i = mon_lengths[isleap(y)][yourtm.tm_mon]; 1670 if (yourtm.tm_mday <= i) 1671 break; 1672 yourtm.tm_mday -= i; 1673 if (++yourtm.tm_mon >= MONSPERYEAR) { 1674 yourtm.tm_mon = 0; 1675 if (long_increment_overflow(&y, 1)) 1676 return WRONG; 1677 } 1678 } 1679 if (long_increment_overflow(&y, -TM_YEAR_BASE)) 1680 return WRONG; 1681 yourtm.tm_year = y; 1682 if (yourtm.tm_year != y) 1683 return WRONG; 1684 if (yourtm.tm_sec >= 0 && yourtm.tm_sec < SECSPERMIN) 1685 saved_seconds = 0; 1686 else if (y + TM_YEAR_BASE < EPOCH_YEAR) { 1687 /* 1688 ** We can't set tm_sec to 0, because that might push the 1689 ** time below the minimum representable time. 1690 ** Set tm_sec to 59 instead. 1691 ** This assumes that the minimum representable time is 1692 ** not in the same minute that a leap second was deleted from, 1693 ** which is a safer assumption than using 58 would be. 1694 */ 1695 if (increment_overflow(&yourtm.tm_sec, 1 - SECSPERMIN)) 1696 return WRONG; 1697 saved_seconds = yourtm.tm_sec; 1698 yourtm.tm_sec = SECSPERMIN - 1; 1699 } else { 1700 saved_seconds = yourtm.tm_sec; 1701 yourtm.tm_sec = 0; 1702 } 1703 /* 1704 ** Do a binary search (this works whatever time_t's type is). 1705 */ 1706 lo = 1; 1707 for (i = 0; i < (int) TYPE_BIT(time_t) - 1; ++i) 1708 lo *= 2; 1709 hi = -(lo + 1); 1710 for ( ; ; ) { 1711 t = lo / 2 + hi / 2; 1712 if (t < lo) 1713 t = lo; 1714 else if (t > hi) 1715 t = hi; 1716 if ((*funcp)(&t, offset, &mytm) == NULL) { 1717 /* 1718 ** Assume that t is too extreme to be represented in 1719 ** a struct tm; arrange things so that it is less 1720 ** extreme on the next pass. 1721 */ 1722 dir = (t > 0) ? 1 : -1; 1723 } else 1724 dir = tmcomp(&mytm, &yourtm); 1725 if (dir != 0) { 1726 if (t == lo) { 1727 ++t; 1728 if (t <= lo) 1729 return WRONG; 1730 ++lo; 1731 } else if (t == hi) { 1732 --t; 1733 if (t >= hi) 1734 return WRONG; 1735 --hi; 1736 } 1737 if (lo > hi) 1738 return WRONG; 1739 if (dir > 0) 1740 hi = t; 1741 else 1742 lo = t; 1743 continue; 1744 } 1745 if (yourtm.tm_isdst < 0 || mytm.tm_isdst == yourtm.tm_isdst) 1746 break; 1747 /* 1748 ** Right time, wrong type. 1749 ** Hunt for right time, right type. 1750 ** It's okay to guess wrong since the guess 1751 ** gets checked. 1752 */ 1753 sp = (const struct state *) 1754 ((funcp == localsub) ? lclptr : gmtptr); 1755 if (sp == NULL) 1756 return WRONG; 1757 for (i = sp->typecnt - 1; i >= 0; --i) { 1758 if (sp->ttis[i].tt_isdst != yourtm.tm_isdst) 1759 continue; 1760 for (j = sp->typecnt - 1; j >= 0; --j) { 1761 if (sp->ttis[j].tt_isdst == yourtm.tm_isdst) 1762 continue; 1763 newt = t + sp->ttis[j].tt_gmtoff - 1764 sp->ttis[i].tt_gmtoff; 1765 if ((*funcp)(&newt, offset, &mytm) == NULL) 1766 continue; 1767 if (tmcomp(&mytm, &yourtm) != 0) 1768 continue; 1769 if (mytm.tm_isdst != yourtm.tm_isdst) 1770 continue; 1771 /* 1772 ** We have a match. 1773 */ 1774 t = newt; 1775 goto label; 1776 } 1777 } 1778 return WRONG; 1779 } 1780 label: 1781 newt = t + saved_seconds; 1782 if ((newt < t) != (saved_seconds < 0)) 1783 return WRONG; 1784 t = newt; 1785 if ((*funcp)(&t, offset, tmp)) 1786 *okayp = TRUE; 1787 return t; 1788 } 1789 1790 static time_t 1791 time2(struct tm *tmp, struct tm * (*funcp)(const time_t *, long, struct tm *), 1792 long offset, int *okayp) 1793 { 1794 time_t t; 1795 1796 /* 1797 ** First try without normalization of seconds 1798 ** (in case tm_sec contains a value associated with a leap second). 1799 ** If that fails, try with normalization of seconds. 1800 */ 1801 t = time2sub(tmp, funcp, offset, okayp, FALSE); 1802 return *okayp ? t : time2sub(tmp, funcp, offset, okayp, TRUE); 1803 } 1804 1805 static time_t 1806 time1(struct tm *tmp, struct tm * (*funcp)(const time_t *, long, struct tm *), 1807 long offset) 1808 { 1809 time_t t; 1810 const struct state * sp; 1811 int samei, otheri; 1812 int sameind, otherind; 1813 int i; 1814 int nseen; 1815 int seen[TZ_MAX_TYPES]; 1816 int types[TZ_MAX_TYPES]; 1817 int okay; 1818 1819 if (tmp == NULL) { 1820 errno = EINVAL; 1821 return WRONG; 1822 } 1823 if (tmp->tm_isdst > 1) 1824 tmp->tm_isdst = 1; 1825 t = time2(tmp, funcp, offset, &okay); 1826 #ifdef PCTS 1827 /* 1828 ** PCTS code courtesy Grant Sullivan. 1829 */ 1830 if (okay) 1831 return t; 1832 if (tmp->tm_isdst < 0) 1833 tmp->tm_isdst = 0; /* reset to std and try again */ 1834 #endif /* defined PCTS */ 1835 #ifndef PCTS 1836 if (okay || tmp->tm_isdst < 0) 1837 return t; 1838 #endif /* !defined PCTS */ 1839 /* 1840 ** We're supposed to assume that somebody took a time of one type 1841 ** and did some math on it that yielded a "struct tm" that's bad. 1842 ** We try to divine the type they started from and adjust to the 1843 ** type they need. 1844 */ 1845 sp = (const struct state *) ((funcp == localsub) ? lclptr : gmtptr); 1846 if (sp == NULL) 1847 return WRONG; 1848 for (i = 0; i < sp->typecnt; ++i) 1849 seen[i] = FALSE; 1850 nseen = 0; 1851 for (i = sp->timecnt - 1; i >= 0; --i) { 1852 if (!seen[sp->types[i]]) { 1853 seen[sp->types[i]] = TRUE; 1854 types[nseen++] = sp->types[i]; 1855 } 1856 } 1857 for (sameind = 0; sameind < nseen; ++sameind) { 1858 samei = types[sameind]; 1859 if (sp->ttis[samei].tt_isdst != tmp->tm_isdst) 1860 continue; 1861 for (otherind = 0; otherind < nseen; ++otherind) { 1862 otheri = types[otherind]; 1863 if (sp->ttis[otheri].tt_isdst == tmp->tm_isdst) 1864 continue; 1865 tmp->tm_sec += sp->ttis[otheri].tt_gmtoff - 1866 sp->ttis[samei].tt_gmtoff; 1867 tmp->tm_isdst = !tmp->tm_isdst; 1868 t = time2(tmp, funcp, offset, &okay); 1869 if (okay) 1870 return t; 1871 tmp->tm_sec -= sp->ttis[otheri].tt_gmtoff - 1872 sp->ttis[samei].tt_gmtoff; 1873 tmp->tm_isdst = !tmp->tm_isdst; 1874 } 1875 } 1876 return WRONG; 1877 } 1878 1879 time_t 1880 mktime(struct tm *tmp) 1881 { 1882 time_t ret; 1883 1884 _THREAD_PRIVATE_MUTEX_LOCK(lcl); 1885 tzset_basic(); 1886 ret = time1(tmp, localsub, 0L); 1887 _THREAD_PRIVATE_MUTEX_UNLOCK(lcl); 1888 return ret; 1889 } 1890 DEF_STRONG(mktime); 1891 1892 #ifdef STD_INSPIRED 1893 1894 time_t 1895 timelocal(struct tm *tmp) 1896 { 1897 if (tmp != NULL) 1898 tmp->tm_isdst = -1; /* in case it wasn't initialized */ 1899 return mktime(tmp); 1900 } 1901 1902 time_t 1903 timegm(struct tm *tmp) 1904 { 1905 if (tmp != NULL) 1906 tmp->tm_isdst = 0; 1907 return time1(tmp, gmtsub, 0L); 1908 } 1909 1910 time_t 1911 timeoff(struct tm *tmp, long offset) 1912 { 1913 if (tmp != NULL) 1914 tmp->tm_isdst = 0; 1915 return time1(tmp, gmtsub, offset); 1916 } 1917 1918 #endif /* defined STD_INSPIRED */ 1919 1920 /* 1921 ** XXX--is the below the right way to conditionalize?? 1922 */ 1923 1924 #ifdef STD_INSPIRED 1925 1926 /* 1927 ** IEEE Std 1003.1-1988 (POSIX) legislates that 536457599 1928 ** shall correspond to "Wed Dec 31 23:59:59 UTC 1986", which 1929 ** is not the case if we are accounting for leap seconds. 1930 ** So, we provide the following conversion routines for use 1931 ** when exchanging timestamps with POSIX conforming systems. 1932 */ 1933 1934 static long 1935 leapcorr(time_t *timep) 1936 { 1937 struct state * sp; 1938 struct lsinfo * lp; 1939 int i; 1940 1941 sp = lclptr; 1942 i = sp->leapcnt; 1943 while (--i >= 0) { 1944 lp = &sp->lsis[i]; 1945 if (*timep >= lp->ls_trans) 1946 return lp->ls_corr; 1947 } 1948 return 0; 1949 } 1950 1951 time_t 1952 time2posix(time_t t) 1953 { 1954 tzset(); 1955 return t - leapcorr(&t); 1956 } 1957 1958 time_t 1959 posix2time(time_t t) 1960 { 1961 time_t x; 1962 time_t y; 1963 1964 tzset(); 1965 /* 1966 ** For a positive leap second hit, the result 1967 ** is not unique. For a negative leap second 1968 ** hit, the corresponding time doesn't exist, 1969 ** so we return an adjacent second. 1970 */ 1971 x = t + leapcorr(&t); 1972 y = x - leapcorr(&x); 1973 if (y < t) { 1974 do { 1975 x++; 1976 y = x - leapcorr(&x); 1977 } while (y < t); 1978 if (t != y) 1979 return x - 1; 1980 } else if (y > t) { 1981 do { 1982 --x; 1983 y = x - leapcorr(&x); 1984 } while (y > t); 1985 if (t != y) 1986 return x + 1; 1987 } 1988 return x; 1989 } 1990 1991 #endif /* defined STD_INSPIRED */ 1992