1 /* $OpenBSD: localtime.c,v 1.61 2019/06/28 13:32:42 deraadt 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 long timezone = 0; 218 int daylight = 0; 219 220 static long 221 detzcode(const char *codep) 222 { 223 long result; 224 int i; 225 226 result = (codep[0] & 0x80) ? ~0L : 0; 227 for (i = 0; i < 4; ++i) 228 result = (result << 8) | (codep[i] & 0xff); 229 return result; 230 } 231 232 static time_t 233 detzcode64(const char *codep) 234 { 235 time_t result; 236 int i; 237 238 result = (codep[0] & 0x80) ? (~(int_fast64_t) 0) : 0; 239 for (i = 0; i < 8; ++i) 240 result = result * 256 + (codep[i] & 0xff); 241 return result; 242 } 243 244 static void 245 settzname(void) 246 { 247 struct state * const sp = lclptr; 248 int i; 249 250 tzname[0] = wildabbr; 251 tzname[1] = wildabbr; 252 daylight = 0; 253 timezone = 0; 254 if (sp == NULL) { 255 tzname[0] = tzname[1] = (char *)gmt; 256 return; 257 } 258 /* 259 ** And to get the latest zone names into tzname. . . 260 */ 261 for (i = 0; i < sp->timecnt; ++i) { 262 const struct ttinfo *ttisp = &sp->ttis[sp->types[i]]; 263 264 tzname[ttisp->tt_isdst] = &sp->chars[ttisp->tt_abbrind]; 265 if (ttisp->tt_isdst) 266 daylight = 1; 267 if (!ttisp->tt_isdst) 268 timezone = -(ttisp->tt_gmtoff); 269 } 270 /* 271 ** Finally, scrub the abbreviations. 272 ** First, replace bogus characters. 273 */ 274 for (i = 0; i < sp->charcnt; ++i) { 275 if (strchr(TZ_ABBR_CHAR_SET, sp->chars[i]) == NULL) 276 sp->chars[i] = TZ_ABBR_ERR_CHAR; 277 } 278 /* 279 ** Second, truncate long abbreviations. 280 */ 281 for (i = 0; i < sp->typecnt; ++i) { 282 const struct ttinfo *ttisp = &sp->ttis[i]; 283 char *cp = &sp->chars[ttisp->tt_abbrind]; 284 285 if (strlen(cp) > TZ_ABBR_MAX_LEN && 286 strcmp(cp, GRANDPARENTED) != 0) 287 *(cp + TZ_ABBR_MAX_LEN) = '\0'; 288 } 289 } 290 291 static int 292 differ_by_repeat(time_t t1, time_t t0) 293 { 294 if (TYPE_BIT(time_t) - 1 < SECSPERREPEAT_BITS) 295 return 0; 296 return (int64_t)t1 - t0 == SECSPERREPEAT; 297 } 298 299 static int 300 tzload(const char *name, struct state *sp, int doextend) 301 { 302 const char * p; 303 int i; 304 int fid; 305 int stored; 306 int nread; 307 typedef union { 308 struct tzhead tzhead; 309 char buf[2 * sizeof(struct tzhead) + 310 2 * sizeof *sp + 311 4 * TZ_MAX_TIMES]; 312 } u_t; 313 u_t * up; 314 char fullname[PATH_MAX]; 315 316 up = calloc(1, sizeof *up); 317 if (up == NULL) 318 return -1; 319 320 sp->goback = sp->goahead = FALSE; 321 if (name != NULL && issetugid() != 0) { 322 if ((name[0] == ':' && (strchr(name, '/') || strstr(name, ".."))) || 323 name[0] == '/' || strchr(name, '.')) 324 name = NULL; 325 } 326 if (name == NULL && (name = TZDEFAULT) == NULL) 327 goto oops; 328 329 if (name[0] == ':') 330 ++name; 331 if (name[0] != '/') { 332 if ((p = TZDIR) == NULL) 333 goto oops; 334 if ((strlen(p) + strlen(name) + 1) >= sizeof fullname) 335 goto oops; 336 strlcpy(fullname, p, sizeof fullname); 337 strlcat(fullname, "/", sizeof fullname); 338 strlcat(fullname, name, sizeof fullname); 339 name = fullname; 340 } 341 if ((fid = open(name, O_RDONLY)) == -1) 342 goto oops; 343 344 nread = read(fid, up->buf, sizeof up->buf); 345 if (close(fid) == -1 || nread <= 0) 346 goto oops; 347 for (stored = 4; stored <= 8; stored *= 2) { 348 int ttisstdcnt; 349 int ttisgmtcnt; 350 351 ttisstdcnt = (int) detzcode(up->tzhead.tzh_ttisstdcnt); 352 ttisgmtcnt = (int) detzcode(up->tzhead.tzh_ttisgmtcnt); 353 sp->leapcnt = (int) detzcode(up->tzhead.tzh_leapcnt); 354 sp->timecnt = (int) detzcode(up->tzhead.tzh_timecnt); 355 sp->typecnt = (int) detzcode(up->tzhead.tzh_typecnt); 356 sp->charcnt = (int) detzcode(up->tzhead.tzh_charcnt); 357 p = up->tzhead.tzh_charcnt + sizeof up->tzhead.tzh_charcnt; 358 if (sp->leapcnt < 0 || sp->leapcnt > TZ_MAX_LEAPS || 359 sp->typecnt <= 0 || sp->typecnt > TZ_MAX_TYPES || 360 sp->timecnt < 0 || sp->timecnt > TZ_MAX_TIMES || 361 sp->charcnt < 0 || sp->charcnt > TZ_MAX_CHARS || 362 (ttisstdcnt != sp->typecnt && ttisstdcnt != 0) || 363 (ttisgmtcnt != sp->typecnt && ttisgmtcnt != 0)) 364 goto oops; 365 if (nread - (p - up->buf) < 366 sp->timecnt * stored + /* ats */ 367 sp->timecnt + /* types */ 368 sp->typecnt * 6 + /* ttinfos */ 369 sp->charcnt + /* chars */ 370 sp->leapcnt * (stored + 4) + /* lsinfos */ 371 ttisstdcnt + /* ttisstds */ 372 ttisgmtcnt) /* ttisgmts */ 373 goto oops; 374 for (i = 0; i < sp->timecnt; ++i) { 375 sp->ats[i] = (stored == 4) ? 376 detzcode(p) : detzcode64(p); 377 p += stored; 378 } 379 for (i = 0; i < sp->timecnt; ++i) { 380 sp->types[i] = (unsigned char) *p++; 381 if (sp->types[i] >= sp->typecnt) 382 goto oops; 383 } 384 for (i = 0; i < sp->typecnt; ++i) { 385 struct ttinfo * ttisp; 386 387 ttisp = &sp->ttis[i]; 388 ttisp->tt_gmtoff = detzcode(p); 389 p += 4; 390 ttisp->tt_isdst = (unsigned char) *p++; 391 if (ttisp->tt_isdst != 0 && ttisp->tt_isdst != 1) 392 goto oops; 393 ttisp->tt_abbrind = (unsigned char) *p++; 394 if (ttisp->tt_abbrind < 0 || 395 ttisp->tt_abbrind > sp->charcnt) 396 goto oops; 397 } 398 for (i = 0; i < sp->charcnt; ++i) 399 sp->chars[i] = *p++; 400 sp->chars[i] = '\0'; /* ensure '\0' at end */ 401 for (i = 0; i < sp->leapcnt; ++i) { 402 struct lsinfo * lsisp; 403 404 lsisp = &sp->lsis[i]; 405 lsisp->ls_trans = (stored == 4) ? 406 detzcode(p) : detzcode64(p); 407 p += stored; 408 lsisp->ls_corr = detzcode(p); 409 p += 4; 410 } 411 for (i = 0; i < sp->typecnt; ++i) { 412 struct ttinfo * ttisp; 413 414 ttisp = &sp->ttis[i]; 415 if (ttisstdcnt == 0) 416 ttisp->tt_ttisstd = FALSE; 417 else { 418 ttisp->tt_ttisstd = *p++; 419 if (ttisp->tt_ttisstd != TRUE && 420 ttisp->tt_ttisstd != FALSE) 421 goto oops; 422 } 423 } 424 for (i = 0; i < sp->typecnt; ++i) { 425 struct ttinfo * ttisp; 426 427 ttisp = &sp->ttis[i]; 428 if (ttisgmtcnt == 0) 429 ttisp->tt_ttisgmt = FALSE; 430 else { 431 ttisp->tt_ttisgmt = *p++; 432 if (ttisp->tt_ttisgmt != TRUE && 433 ttisp->tt_ttisgmt != FALSE) 434 goto oops; 435 } 436 } 437 /* 438 ** Out-of-sort ats should mean we're running on a 439 ** signed time_t system but using a data file with 440 ** unsigned values (or vice versa). 441 */ 442 for (i = 0; i < sp->timecnt - 2; ++i) 443 if (sp->ats[i] > sp->ats[i + 1]) { 444 ++i; 445 /* 446 ** Ignore the end (easy). 447 */ 448 sp->timecnt = i; 449 break; 450 } 451 /* 452 ** If this is an old file, we're done. 453 */ 454 if (up->tzhead.tzh_version[0] == '\0') 455 break; 456 nread -= p - up->buf; 457 for (i = 0; i < nread; ++i) 458 up->buf[i] = p[i]; 459 /* 460 ** If this is a narrow integer time_t system, we're done. 461 */ 462 if (stored >= sizeof(time_t)) 463 break; 464 } 465 if (doextend && nread > 2 && 466 up->buf[0] == '\n' && up->buf[nread - 1] == '\n' && 467 sp->typecnt + 2 <= TZ_MAX_TYPES) { 468 struct state ts; 469 int result; 470 471 up->buf[nread - 1] = '\0'; 472 result = tzparse(&up->buf[1], &ts, FALSE); 473 if (result == 0 && ts.typecnt == 2 && 474 sp->charcnt + ts.charcnt <= TZ_MAX_CHARS) { 475 for (i = 0; i < 2; ++i) 476 ts.ttis[i].tt_abbrind += 477 sp->charcnt; 478 for (i = 0; i < ts.charcnt; ++i) 479 sp->chars[sp->charcnt++] = 480 ts.chars[i]; 481 i = 0; 482 while (i < ts.timecnt && 483 ts.ats[i] <= 484 sp->ats[sp->timecnt - 1]) 485 ++i; 486 while (i < ts.timecnt && 487 sp->timecnt < TZ_MAX_TIMES) { 488 sp->ats[sp->timecnt] = 489 ts.ats[i]; 490 sp->types[sp->timecnt] = 491 sp->typecnt + 492 ts.types[i]; 493 ++sp->timecnt; 494 ++i; 495 } 496 sp->ttis[sp->typecnt++] = ts.ttis[0]; 497 sp->ttis[sp->typecnt++] = ts.ttis[1]; 498 } 499 } 500 if (sp->timecnt > 1) { 501 for (i = 1; i < sp->timecnt; ++i) { 502 if (typesequiv(sp, sp->types[i], sp->types[0]) && 503 differ_by_repeat(sp->ats[i], sp->ats[0])) { 504 sp->goback = TRUE; 505 break; 506 } 507 } 508 for (i = sp->timecnt - 2; i >= 0; --i) { 509 if (typesequiv(sp, sp->types[sp->timecnt - 1], 510 sp->types[i]) && 511 differ_by_repeat(sp->ats[sp->timecnt - 1], 512 sp->ats[i])) { 513 sp->goahead = TRUE; 514 break; 515 } 516 } 517 } 518 free(up); 519 return 0; 520 oops: 521 free(up); 522 return -1; 523 } 524 525 static int 526 typesequiv(const struct state *sp, int a, int b) 527 { 528 int result; 529 530 if (sp == NULL || 531 a < 0 || a >= sp->typecnt || 532 b < 0 || b >= sp->typecnt) 533 result = FALSE; 534 else { 535 const struct ttinfo * ap = &sp->ttis[a]; 536 const struct ttinfo * bp = &sp->ttis[b]; 537 result = ap->tt_gmtoff == bp->tt_gmtoff && 538 ap->tt_isdst == bp->tt_isdst && 539 ap->tt_ttisstd == bp->tt_ttisstd && 540 ap->tt_ttisgmt == bp->tt_ttisgmt && 541 strcmp(&sp->chars[ap->tt_abbrind], 542 &sp->chars[bp->tt_abbrind]) == 0; 543 } 544 return result; 545 } 546 547 static const int mon_lengths[2][MONSPERYEAR] = { 548 { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }, 549 { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 } 550 }; 551 552 static const int year_lengths[2] = { 553 DAYSPERNYEAR, DAYSPERLYEAR 554 }; 555 556 /* 557 ** Given a pointer into a time zone string, scan until a character that is not 558 ** a valid character in a zone name is found. Return a pointer to that 559 ** character. 560 */ 561 562 static const char * 563 getzname(const char *strp) 564 { 565 char c; 566 567 while ((c = *strp) != '\0' && !isdigit((unsigned char)c) && c != ',' && c != '-' && 568 c != '+') 569 ++strp; 570 return strp; 571 } 572 573 /* 574 ** Given a pointer into an extended time zone string, scan until the ending 575 ** delimiter of the zone name is located. Return a pointer to the delimiter. 576 ** 577 ** As with getzname above, the legal character set is actually quite 578 ** restricted, with other characters producing undefined results. 579 ** We don't do any checking here; checking is done later in common-case code. 580 */ 581 582 static const char * 583 getqzname(const char *strp, const int delim) 584 { 585 int c; 586 587 while ((c = *strp) != '\0' && c != delim) 588 ++strp; 589 return strp; 590 } 591 592 /* 593 ** Given a pointer into a time zone string, extract a number from that string. 594 ** Check that the number is within a specified range; if it is not, return 595 ** NULL. 596 ** Otherwise, return a pointer to the first character not part of the number. 597 */ 598 599 static const char * 600 getnum(const char *strp, int *nump, int min, int max) 601 { 602 char c; 603 int num; 604 605 if (strp == NULL || !isdigit((unsigned char)(c = *strp))) 606 return NULL; 607 num = 0; 608 do { 609 num = num * 10 + (c - '0'); 610 if (num > max) 611 return NULL; /* illegal value */ 612 c = *++strp; 613 } while (isdigit((unsigned char)c)); 614 if (num < min) 615 return NULL; /* illegal value */ 616 *nump = num; 617 return strp; 618 } 619 620 /* 621 ** Given a pointer into a time zone string, extract a number of seconds, 622 ** in hh[:mm[:ss]] form, from the string. 623 ** If any error occurs, return NULL. 624 ** Otherwise, return a pointer to the first character not part of the number 625 ** of seconds. 626 */ 627 628 static const char * 629 getsecs(const char *strp, long *secsp) 630 { 631 int num; 632 633 /* 634 ** `HOURSPERDAY * DAYSPERWEEK - 1' allows quasi-Posix rules like 635 ** "M10.4.6/26", which does not conform to Posix, 636 ** but which specifies the equivalent of 637 ** ``02:00 on the first Sunday on or after 23 Oct''. 638 */ 639 strp = getnum(strp, &num, 0, HOURSPERDAY * DAYSPERWEEK - 1); 640 if (strp == NULL) 641 return NULL; 642 *secsp = num * (long) SECSPERHOUR; 643 if (*strp == ':') { 644 ++strp; 645 strp = getnum(strp, &num, 0, MINSPERHOUR - 1); 646 if (strp == NULL) 647 return NULL; 648 *secsp += num * SECSPERMIN; 649 if (*strp == ':') { 650 ++strp; 651 /* `SECSPERMIN' allows for leap seconds. */ 652 strp = getnum(strp, &num, 0, SECSPERMIN); 653 if (strp == NULL) 654 return NULL; 655 *secsp += num; 656 } 657 } 658 return strp; 659 } 660 661 /* 662 ** Given a pointer into a time zone string, extract an offset, in 663 ** [+-]hh[:mm[:ss]] form, from the string. 664 ** If any error occurs, return NULL. 665 ** Otherwise, return a pointer to the first character not part of the time. 666 */ 667 668 static const char * 669 getoffset(const char *strp, long *offsetp) 670 { 671 int neg = 0; 672 673 if (*strp == '-') { 674 neg = 1; 675 ++strp; 676 } else if (*strp == '+') 677 ++strp; 678 strp = getsecs(strp, offsetp); 679 if (strp == NULL) 680 return NULL; /* illegal time */ 681 if (neg) 682 *offsetp = -*offsetp; 683 return strp; 684 } 685 686 /* 687 ** Given a pointer into a time zone string, extract a rule in the form 688 ** date[/time]. See POSIX section 8 for the format of "date" and "time". 689 ** If a valid rule is not found, return NULL. 690 ** Otherwise, return a pointer to the first character not part of the rule. 691 */ 692 693 static const char * 694 getrule(const char *strp, struct rule *rulep) 695 { 696 if (*strp == 'J') { 697 /* 698 ** Julian day. 699 */ 700 rulep->r_type = JULIAN_DAY; 701 ++strp; 702 strp = getnum(strp, &rulep->r_day, 1, DAYSPERNYEAR); 703 } else if (*strp == 'M') { 704 /* 705 ** Month, week, day. 706 */ 707 rulep->r_type = MONTH_NTH_DAY_OF_WEEK; 708 ++strp; 709 strp = getnum(strp, &rulep->r_mon, 1, MONSPERYEAR); 710 if (strp == NULL) 711 return NULL; 712 if (*strp++ != '.') 713 return NULL; 714 strp = getnum(strp, &rulep->r_week, 1, 5); 715 if (strp == NULL) 716 return NULL; 717 if (*strp++ != '.') 718 return NULL; 719 strp = getnum(strp, &rulep->r_day, 0, DAYSPERWEEK - 1); 720 } else if (isdigit((unsigned char)*strp)) { 721 /* 722 ** Day of year. 723 */ 724 rulep->r_type = DAY_OF_YEAR; 725 strp = getnum(strp, &rulep->r_day, 0, DAYSPERLYEAR - 1); 726 } else 727 return NULL; /* invalid format */ 728 if (strp == NULL) 729 return NULL; 730 if (*strp == '/') { 731 /* 732 ** Time specified. 733 */ 734 ++strp; 735 strp = getsecs(strp, &rulep->r_time); 736 } else 737 rulep->r_time = 2 * SECSPERHOUR; /* default = 2:00:00 */ 738 return strp; 739 } 740 741 /* 742 ** Given the Epoch-relative time of January 1, 00:00:00 UTC, in a year, the 743 ** year, a rule, and the offset from UTC at the time that rule takes effect, 744 ** calculate the Epoch-relative time that rule takes effect. 745 */ 746 747 static time_t 748 transtime(time_t janfirst, int year, const struct rule *rulep, long offset) 749 { 750 int leapyear; 751 time_t value; 752 int i; 753 int d, m1, yy0, yy1, yy2, dow; 754 755 value = 0; 756 leapyear = isleap(year); 757 switch (rulep->r_type) { 758 759 case JULIAN_DAY: 760 /* 761 ** Jn - Julian day, 1 == January 1, 60 == March 1 even in leap 762 ** years. 763 ** In non-leap years, or if the day number is 59 or less, just 764 ** add SECSPERDAY times the day number-1 to the time of 765 ** January 1, midnight, to get the day. 766 */ 767 value = janfirst + (rulep->r_day - 1) * SECSPERDAY; 768 if (leapyear && rulep->r_day >= 60) 769 value += SECSPERDAY; 770 break; 771 772 case DAY_OF_YEAR: 773 /* 774 ** n - day of year. 775 ** Just add SECSPERDAY times the day number to the time of 776 ** January 1, midnight, to get the day. 777 */ 778 value = janfirst + rulep->r_day * SECSPERDAY; 779 break; 780 781 case MONTH_NTH_DAY_OF_WEEK: 782 /* 783 ** Mm.n.d - nth "dth day" of month m. 784 */ 785 value = janfirst; 786 for (i = 0; i < rulep->r_mon - 1; ++i) 787 value += mon_lengths[leapyear][i] * SECSPERDAY; 788 789 /* 790 ** Use Zeller's Congruence to get day-of-week of first day of 791 ** month. 792 */ 793 m1 = (rulep->r_mon + 9) % 12 + 1; 794 yy0 = (rulep->r_mon <= 2) ? (year - 1) : year; 795 yy1 = yy0 / 100; 796 yy2 = yy0 % 100; 797 dow = ((26 * m1 - 2) / 10 + 798 1 + yy2 + yy2 / 4 + yy1 / 4 - 2 * yy1) % 7; 799 if (dow < 0) 800 dow += DAYSPERWEEK; 801 802 /* 803 ** "dow" is the day-of-week of the first day of the month. Get 804 ** the day-of-month (zero-origin) of the first "dow" day of the 805 ** month. 806 */ 807 d = rulep->r_day - dow; 808 if (d < 0) 809 d += DAYSPERWEEK; 810 for (i = 1; i < rulep->r_week; ++i) { 811 if (d + DAYSPERWEEK >= 812 mon_lengths[leapyear][rulep->r_mon - 1]) 813 break; 814 d += DAYSPERWEEK; 815 } 816 817 /* 818 ** "d" is the day-of-month (zero-origin) of the day we want. 819 */ 820 value += d * SECSPERDAY; 821 break; 822 } 823 824 /* 825 ** "value" is the Epoch-relative time of 00:00:00 UTC on the day in 826 ** question. To get the Epoch-relative time of the specified local 827 ** time on that day, add the transition time and the current offset 828 ** from UTC. 829 */ 830 return value + rulep->r_time + offset; 831 } 832 833 /* 834 ** Given a POSIX section 8-style TZ string, fill in the rule tables as 835 ** appropriate. 836 */ 837 838 static int 839 tzparse(const char *name, struct state *sp, int lastditch) 840 { 841 const char * stdname; 842 const char * dstname; 843 size_t stdlen; 844 size_t dstlen; 845 long stdoffset; 846 long dstoffset; 847 time_t * atp; 848 unsigned char * typep; 849 char * cp; 850 int load_result; 851 static struct ttinfo zttinfo; 852 853 dstname = NULL; 854 stdname = name; 855 if (lastditch) { 856 stdlen = strlen(name); /* length of standard zone name */ 857 name += stdlen; 858 if (stdlen >= sizeof sp->chars) 859 stdlen = (sizeof sp->chars) - 1; 860 stdoffset = 0; 861 } else { 862 if (*name == '<') { 863 name++; 864 stdname = name; 865 name = getqzname(name, '>'); 866 if (*name != '>') 867 return (-1); 868 stdlen = name - stdname; 869 name++; 870 } else { 871 name = getzname(name); 872 stdlen = name - stdname; 873 } 874 if (*name == '\0') 875 return -1; 876 name = getoffset(name, &stdoffset); 877 if (name == NULL) 878 return -1; 879 } 880 load_result = tzload(TZDEFRULES, sp, FALSE); 881 if (load_result != 0) 882 sp->leapcnt = 0; /* so, we're off a little */ 883 if (*name != '\0') { 884 if (*name == '<') { 885 dstname = ++name; 886 name = getqzname(name, '>'); 887 if (*name != '>') 888 return -1; 889 dstlen = name - dstname; 890 name++; 891 } else { 892 dstname = name; 893 name = getzname(name); 894 dstlen = name - dstname; /* length of DST zone name */ 895 } 896 if (*name != '\0' && *name != ',' && *name != ';') { 897 name = getoffset(name, &dstoffset); 898 if (name == NULL) 899 return -1; 900 } else 901 dstoffset = stdoffset - SECSPERHOUR; 902 if (*name == '\0' && load_result != 0) 903 name = TZDEFRULESTRING; 904 if (*name == ',' || *name == ';') { 905 struct rule start; 906 struct rule end; 907 int year; 908 time_t janfirst; 909 time_t starttime; 910 time_t endtime; 911 912 ++name; 913 if ((name = getrule(name, &start)) == NULL) 914 return -1; 915 if (*name++ != ',') 916 return -1; 917 if ((name = getrule(name, &end)) == NULL) 918 return -1; 919 if (*name != '\0') 920 return -1; 921 sp->typecnt = 2; /* standard time and DST */ 922 /* 923 ** Two transitions per year, from EPOCH_YEAR forward. 924 */ 925 sp->ttis[0] = sp->ttis[1] = zttinfo; 926 sp->ttis[0].tt_gmtoff = -dstoffset; 927 sp->ttis[0].tt_isdst = 1; 928 sp->ttis[0].tt_abbrind = stdlen + 1; 929 sp->ttis[1].tt_gmtoff = -stdoffset; 930 sp->ttis[1].tt_isdst = 0; 931 sp->ttis[1].tt_abbrind = 0; 932 atp = sp->ats; 933 typep = sp->types; 934 janfirst = 0; 935 sp->timecnt = 0; 936 for (year = EPOCH_YEAR; 937 sp->timecnt + 2 <= TZ_MAX_TIMES; 938 ++year) { 939 time_t newfirst; 940 941 starttime = transtime(janfirst, year, &start, 942 stdoffset); 943 endtime = transtime(janfirst, year, &end, 944 dstoffset); 945 if (starttime > endtime) { 946 *atp++ = endtime; 947 *typep++ = 1; /* DST ends */ 948 *atp++ = starttime; 949 *typep++ = 0; /* DST begins */ 950 } else { 951 *atp++ = starttime; 952 *typep++ = 0; /* DST begins */ 953 *atp++ = endtime; 954 *typep++ = 1; /* DST ends */ 955 } 956 sp->timecnt += 2; 957 newfirst = janfirst; 958 newfirst += year_lengths[isleap(year)] * 959 SECSPERDAY; 960 if (newfirst <= janfirst) 961 break; 962 janfirst = newfirst; 963 } 964 } else { 965 long theirstdoffset; 966 long theirdstoffset; 967 long theiroffset; 968 int isdst; 969 int i; 970 int j; 971 972 if (*name != '\0') 973 return -1; 974 /* 975 ** Initial values of theirstdoffset and theirdstoffset. 976 */ 977 theirstdoffset = 0; 978 for (i = 0; i < sp->timecnt; ++i) { 979 j = sp->types[i]; 980 if (!sp->ttis[j].tt_isdst) { 981 theirstdoffset = 982 -sp->ttis[j].tt_gmtoff; 983 break; 984 } 985 } 986 theirdstoffset = 0; 987 for (i = 0; i < sp->timecnt; ++i) { 988 j = sp->types[i]; 989 if (sp->ttis[j].tt_isdst) { 990 theirdstoffset = 991 -sp->ttis[j].tt_gmtoff; 992 break; 993 } 994 } 995 /* 996 ** Initially we're assumed to be in standard time. 997 */ 998 isdst = FALSE; 999 theiroffset = theirstdoffset; 1000 /* 1001 ** Now juggle transition times and types 1002 ** tracking offsets as you do. 1003 */ 1004 for (i = 0; i < sp->timecnt; ++i) { 1005 j = sp->types[i]; 1006 sp->types[i] = sp->ttis[j].tt_isdst; 1007 if (sp->ttis[j].tt_ttisgmt) { 1008 /* No adjustment to transition time */ 1009 } else { 1010 /* 1011 ** If summer time is in effect, and the 1012 ** transition time was not specified as 1013 ** standard time, add the summer time 1014 ** offset to the transition time; 1015 ** otherwise, add the standard time 1016 ** offset to the transition time. 1017 */ 1018 /* 1019 ** Transitions from DST to DDST 1020 ** will effectively disappear since 1021 ** POSIX provides for only one DST 1022 ** offset. 1023 */ 1024 if (isdst && !sp->ttis[j].tt_ttisstd) { 1025 sp->ats[i] += dstoffset - 1026 theirdstoffset; 1027 } else { 1028 sp->ats[i] += stdoffset - 1029 theirstdoffset; 1030 } 1031 } 1032 theiroffset = -sp->ttis[j].tt_gmtoff; 1033 if (sp->ttis[j].tt_isdst) 1034 theirdstoffset = theiroffset; 1035 else 1036 theirstdoffset = theiroffset; 1037 } 1038 /* 1039 ** Finally, fill in ttis. 1040 */ 1041 sp->ttis[0] = sp->ttis[1] = zttinfo; 1042 sp->ttis[0].tt_gmtoff = -stdoffset; 1043 sp->ttis[0].tt_isdst = FALSE; 1044 sp->ttis[0].tt_abbrind = 0; 1045 sp->ttis[1].tt_gmtoff = -dstoffset; 1046 sp->ttis[1].tt_isdst = TRUE; 1047 sp->ttis[1].tt_abbrind = stdlen + 1; 1048 sp->typecnt = 2; 1049 } 1050 } else { 1051 dstlen = 0; 1052 sp->typecnt = 1; /* only standard time */ 1053 sp->timecnt = 0; 1054 sp->ttis[0] = zttinfo; 1055 sp->ttis[0].tt_gmtoff = -stdoffset; 1056 sp->ttis[0].tt_isdst = 0; 1057 sp->ttis[0].tt_abbrind = 0; 1058 } 1059 sp->charcnt = stdlen + 1; 1060 if (dstlen != 0) 1061 sp->charcnt += dstlen + 1; 1062 if ((size_t) sp->charcnt > sizeof sp->chars) 1063 return -1; 1064 cp = sp->chars; 1065 strlcpy(cp, stdname, stdlen + 1); 1066 cp += stdlen + 1; 1067 if (dstlen != 0) { 1068 strlcpy(cp, dstname, dstlen + 1); 1069 } 1070 return 0; 1071 } 1072 1073 static void 1074 gmtload(struct state *sp) 1075 { 1076 if (tzload(gmt, sp, TRUE) != 0) 1077 (void) tzparse(gmt, sp, TRUE); 1078 } 1079 1080 static void 1081 tzsetwall_basic(void) 1082 { 1083 if (lcl_is_set < 0) 1084 return; 1085 lcl_is_set = -1; 1086 1087 if (lclptr == NULL) { 1088 lclptr = calloc(1, sizeof *lclptr); 1089 if (lclptr == NULL) { 1090 settzname(); /* all we can do */ 1091 return; 1092 } 1093 } 1094 if (tzload(NULL, lclptr, TRUE) != 0) 1095 gmtload(lclptr); 1096 settzname(); 1097 } 1098 1099 #ifndef STD_INSPIRED 1100 /* 1101 ** A non-static declaration of tzsetwall in a system header file 1102 ** may cause a warning about this upcoming static declaration... 1103 */ 1104 static 1105 #endif /* !defined STD_INSPIRED */ 1106 void 1107 tzsetwall(void) 1108 { 1109 _THREAD_PRIVATE_MUTEX_LOCK(lcl); 1110 tzsetwall_basic(); 1111 _THREAD_PRIVATE_MUTEX_UNLOCK(lcl); 1112 } 1113 1114 static void 1115 tzset_basic(void) 1116 { 1117 const char * name; 1118 1119 name = getenv("TZ"); 1120 if (name == NULL) { 1121 tzsetwall_basic(); 1122 return; 1123 } 1124 1125 if (lcl_is_set > 0 && strcmp(lcl_TZname, name) == 0) 1126 return; 1127 lcl_is_set = strlen(name) < sizeof lcl_TZname; 1128 if (lcl_is_set) 1129 strlcpy(lcl_TZname, name, sizeof lcl_TZname); 1130 1131 if (lclptr == NULL) { 1132 lclptr = calloc(1, sizeof *lclptr); 1133 if (lclptr == NULL) { 1134 settzname(); /* all we can do */ 1135 return; 1136 } 1137 } 1138 if (*name == '\0') { 1139 /* 1140 ** User wants it fast rather than right. 1141 */ 1142 lclptr->leapcnt = 0; /* so, we're off a little */ 1143 lclptr->timecnt = 0; 1144 lclptr->typecnt = 0; 1145 lclptr->ttis[0].tt_isdst = 0; 1146 lclptr->ttis[0].tt_gmtoff = 0; 1147 lclptr->ttis[0].tt_abbrind = 0; 1148 strlcpy(lclptr->chars, gmt, sizeof lclptr->chars); 1149 } else if (tzload(name, lclptr, TRUE) != 0) { 1150 if (name[0] == ':' || tzparse(name, lclptr, FALSE) != 0) 1151 gmtload(lclptr); 1152 } 1153 settzname(); 1154 } 1155 1156 void 1157 tzset(void) 1158 { 1159 _THREAD_PRIVATE_MUTEX_LOCK(lcl); 1160 tzset_basic(); 1161 _THREAD_PRIVATE_MUTEX_UNLOCK(lcl); 1162 } 1163 DEF_WEAK(tzset); 1164 1165 /* 1166 ** The easy way to behave "as if no library function calls" localtime 1167 ** is to not call it--so we drop its guts into "localsub", which can be 1168 ** freely called. (And no, the PANS doesn't require the above behavior-- 1169 ** but it *is* desirable.) 1170 ** 1171 ** The unused offset argument is for the benefit of mktime variants. 1172 */ 1173 1174 static struct tm * 1175 localsub(const time_t *timep, long offset, struct tm *tmp) 1176 { 1177 struct state * sp; 1178 const struct ttinfo * ttisp; 1179 int i; 1180 struct tm * result; 1181 const time_t t = *timep; 1182 1183 sp = lclptr; 1184 if (sp == NULL) 1185 return gmtsub(timep, offset, tmp); 1186 if ((sp->goback && t < sp->ats[0]) || 1187 (sp->goahead && t > sp->ats[sp->timecnt - 1])) { 1188 time_t newt = t; 1189 time_t seconds; 1190 time_t tcycles; 1191 int_fast64_t icycles; 1192 1193 if (t < sp->ats[0]) 1194 seconds = sp->ats[0] - t; 1195 else 1196 seconds = t - sp->ats[sp->timecnt - 1]; 1197 --seconds; 1198 tcycles = seconds / YEARSPERREPEAT / AVGSECSPERYEAR; 1199 ++tcycles; 1200 icycles = tcycles; 1201 if (tcycles - icycles >= 1 || icycles - tcycles >= 1) 1202 return NULL; 1203 seconds = icycles; 1204 seconds *= YEARSPERREPEAT; 1205 seconds *= AVGSECSPERYEAR; 1206 if (t < sp->ats[0]) 1207 newt += seconds; 1208 else 1209 newt -= seconds; 1210 if (newt < sp->ats[0] || 1211 newt > sp->ats[sp->timecnt - 1]) 1212 return NULL; /* "cannot happen" */ 1213 result = localsub(&newt, offset, tmp); 1214 if (result == tmp) { 1215 time_t newy; 1216 1217 newy = tmp->tm_year; 1218 if (t < sp->ats[0]) 1219 newy -= icycles * YEARSPERREPEAT; 1220 else 1221 newy += icycles * YEARSPERREPEAT; 1222 tmp->tm_year = newy; 1223 if (tmp->tm_year != newy) 1224 return NULL; 1225 } 1226 return result; 1227 } 1228 if (sp->timecnt == 0 || t < sp->ats[0]) { 1229 i = 0; 1230 while (sp->ttis[i].tt_isdst) { 1231 if (++i >= sp->typecnt) { 1232 i = 0; 1233 break; 1234 } 1235 } 1236 } else { 1237 int lo = 1; 1238 int hi = sp->timecnt; 1239 1240 while (lo < hi) { 1241 int mid = (lo + hi) >> 1; 1242 1243 if (t < sp->ats[mid]) 1244 hi = mid; 1245 else 1246 lo = mid + 1; 1247 } 1248 i = (int) sp->types[lo - 1]; 1249 } 1250 ttisp = &sp->ttis[i]; 1251 /* 1252 ** To get (wrong) behavior that's compatible with System V Release 2.0 1253 ** you'd replace the statement below with 1254 ** t += ttisp->tt_gmtoff; 1255 ** timesub(&t, 0L, sp, tmp); 1256 */ 1257 result = timesub(&t, ttisp->tt_gmtoff, sp, tmp); 1258 tmp->tm_isdst = ttisp->tt_isdst; 1259 tzname[tmp->tm_isdst] = &sp->chars[ttisp->tt_abbrind]; 1260 tmp->tm_zone = &sp->chars[ttisp->tt_abbrind]; 1261 return result; 1262 } 1263 1264 /* 1265 ** Re-entrant version of localtime. 1266 */ 1267 1268 struct tm * 1269 localtime_r(const time_t *timep, struct tm *p_tm) 1270 { 1271 _THREAD_PRIVATE_MUTEX_LOCK(lcl); 1272 tzset_basic(); 1273 p_tm = localsub(timep, 0L, p_tm); 1274 _THREAD_PRIVATE_MUTEX_UNLOCK(lcl); 1275 return p_tm; 1276 } 1277 DEF_WEAK(localtime_r); 1278 1279 struct tm * 1280 localtime(const time_t *timep) 1281 { 1282 _THREAD_PRIVATE_KEY(localtime); 1283 struct tm * p_tm = (struct tm*)_THREAD_PRIVATE(localtime, tm, NULL); 1284 1285 if (p_tm == NULL) 1286 return NULL; 1287 return localtime_r(timep, p_tm); 1288 } 1289 DEF_STRONG(localtime); 1290 1291 /* 1292 ** gmtsub is to gmtime as localsub is to localtime. 1293 */ 1294 1295 static struct tm * 1296 gmtsub(const time_t *timep, long offset, struct tm *tmp) 1297 { 1298 struct tm * result; 1299 1300 _THREAD_PRIVATE_MUTEX_LOCK(gmt); 1301 if (!gmt_is_set) { 1302 gmt_is_set = TRUE; 1303 gmtptr = calloc(1, sizeof(*gmtptr)); 1304 if (gmtptr != NULL) 1305 gmtload(gmtptr); 1306 } 1307 _THREAD_PRIVATE_MUTEX_UNLOCK(gmt); 1308 result = timesub(timep, offset, gmtptr, tmp); 1309 /* 1310 ** Could get fancy here and deliver something such as 1311 ** "UTC+xxxx" or "UTC-xxxx" if offset is non-zero, 1312 ** but this is no time for a treasure hunt. 1313 */ 1314 if (offset != 0) 1315 tmp->tm_zone = wildabbr; 1316 else { 1317 if (gmtptr == NULL) 1318 tmp->tm_zone = (char *)gmt; 1319 else 1320 tmp->tm_zone = gmtptr->chars; 1321 } 1322 return result; 1323 } 1324 1325 /* 1326 ** Re-entrant version of gmtime. 1327 */ 1328 1329 struct tm * 1330 gmtime_r(const time_t *timep, struct tm *p_tm) 1331 { 1332 return gmtsub(timep, 0L, p_tm); 1333 } 1334 DEF_WEAK(gmtime_r); 1335 1336 struct tm * 1337 gmtime(const time_t *timep) 1338 { 1339 _THREAD_PRIVATE_KEY(gmtime); 1340 struct tm * p_tm = (struct tm*) _THREAD_PRIVATE(gmtime, tm, NULL); 1341 1342 if (p_tm == NULL) 1343 return NULL; 1344 return gmtime_r(timep, p_tm); 1345 1346 } 1347 DEF_WEAK(gmtime); 1348 1349 #ifdef STD_INSPIRED 1350 1351 struct tm * 1352 offtime(const time_t *timep, long offset) 1353 { 1354 return gmtsub(timep, offset, &tm); 1355 } 1356 1357 #endif /* defined STD_INSPIRED */ 1358 1359 /* 1360 ** Return the number of leap years through the end of the given year 1361 ** where, to make the math easy, the answer for year zero is defined as zero. 1362 */ 1363 1364 static int 1365 leaps_thru_end_of(int y) 1366 { 1367 return (y >= 0) ? (y / 4 - y / 100 + y / 400) : 1368 -(leaps_thru_end_of(-(y + 1)) + 1); 1369 } 1370 1371 static struct tm * 1372 timesub(const time_t *timep, long offset, const struct state *sp, struct tm *tmp) 1373 { 1374 const struct lsinfo * lp; 1375 time_t tdays; 1376 int idays; /* unsigned would be so 2003 */ 1377 long rem; 1378 int y; 1379 const int * ip; 1380 long corr; 1381 int hit; 1382 int i; 1383 long seconds; 1384 1385 corr = 0; 1386 hit = 0; 1387 i = (sp == NULL) ? 0 : sp->leapcnt; 1388 while (--i >= 0) { 1389 lp = &sp->lsis[i]; 1390 if (*timep >= lp->ls_trans) { 1391 if (*timep == lp->ls_trans) { 1392 hit = ((i == 0 && lp->ls_corr > 0) || 1393 lp->ls_corr > sp->lsis[i - 1].ls_corr); 1394 if (hit) { 1395 while (i > 0 && 1396 sp->lsis[i].ls_trans == 1397 sp->lsis[i - 1].ls_trans + 1 && 1398 sp->lsis[i].ls_corr == 1399 sp->lsis[i - 1].ls_corr + 1) { 1400 ++hit; 1401 --i; 1402 } 1403 } 1404 } 1405 corr = lp->ls_corr; 1406 break; 1407 } 1408 } 1409 y = EPOCH_YEAR; 1410 tdays = *timep / SECSPERDAY; 1411 rem = *timep - tdays * SECSPERDAY; 1412 while (tdays < 0 || tdays >= year_lengths[isleap(y)]) { 1413 int newy; 1414 time_t tdelta; 1415 int idelta; 1416 int leapdays; 1417 1418 tdelta = tdays / DAYSPERLYEAR; 1419 idelta = tdelta; 1420 if (tdelta - idelta >= 1 || idelta - tdelta >= 1) 1421 return NULL; 1422 if (idelta == 0) 1423 idelta = (tdays < 0) ? -1 : 1; 1424 newy = y; 1425 if (increment_overflow(&newy, idelta)) 1426 return NULL; 1427 leapdays = leaps_thru_end_of(newy - 1) - 1428 leaps_thru_end_of(y - 1); 1429 tdays -= ((time_t) newy - y) * DAYSPERNYEAR; 1430 tdays -= leapdays; 1431 y = newy; 1432 } 1433 1434 seconds = tdays * SECSPERDAY + 0.5; 1435 tdays = seconds / SECSPERDAY; 1436 rem += seconds - tdays * SECSPERDAY; 1437 1438 /* 1439 ** Given the range, we can now fearlessly cast... 1440 */ 1441 idays = tdays; 1442 rem += offset - corr; 1443 while (rem < 0) { 1444 rem += SECSPERDAY; 1445 --idays; 1446 } 1447 while (rem >= SECSPERDAY) { 1448 rem -= SECSPERDAY; 1449 ++idays; 1450 } 1451 while (idays < 0) { 1452 if (increment_overflow(&y, -1)) 1453 return NULL; 1454 idays += year_lengths[isleap(y)]; 1455 } 1456 while (idays >= year_lengths[isleap(y)]) { 1457 idays -= year_lengths[isleap(y)]; 1458 if (increment_overflow(&y, 1)) 1459 return NULL; 1460 } 1461 tmp->tm_year = y; 1462 if (increment_overflow(&tmp->tm_year, -TM_YEAR_BASE)) 1463 return NULL; 1464 tmp->tm_yday = idays; 1465 /* 1466 ** The "extra" mods below avoid overflow problems. 1467 */ 1468 tmp->tm_wday = EPOCH_WDAY + 1469 ((y - EPOCH_YEAR) % DAYSPERWEEK) * 1470 (DAYSPERNYEAR % DAYSPERWEEK) + 1471 leaps_thru_end_of(y - 1) - 1472 leaps_thru_end_of(EPOCH_YEAR - 1) + 1473 idays; 1474 tmp->tm_wday %= DAYSPERWEEK; 1475 if (tmp->tm_wday < 0) 1476 tmp->tm_wday += DAYSPERWEEK; 1477 tmp->tm_hour = (int) (rem / SECSPERHOUR); 1478 rem %= SECSPERHOUR; 1479 tmp->tm_min = (int) (rem / SECSPERMIN); 1480 /* 1481 ** A positive leap second requires a special 1482 ** representation. This uses "... ??:59:60" et seq. 1483 */ 1484 tmp->tm_sec = (int) (rem % SECSPERMIN) + hit; 1485 ip = mon_lengths[isleap(y)]; 1486 for (tmp->tm_mon = 0; idays >= ip[tmp->tm_mon]; ++(tmp->tm_mon)) 1487 idays -= ip[tmp->tm_mon]; 1488 tmp->tm_mday = (int) (idays + 1); 1489 tmp->tm_isdst = 0; 1490 tmp->tm_gmtoff = offset; 1491 return tmp; 1492 } 1493 1494 char * 1495 ctime(const time_t *timep) 1496 { 1497 /* 1498 ** Section 4.12.3.2 of X3.159-1989 requires that 1499 ** The ctime function converts the calendar time pointed to by timer 1500 ** to local time in the form of a string. It is equivalent to 1501 ** asctime(localtime(timer)) 1502 */ 1503 return asctime(localtime(timep)); 1504 } 1505 1506 char * 1507 ctime_r(const time_t *timep, char *buf) 1508 { 1509 struct tm mytm; 1510 1511 return asctime_r(localtime_r(timep, &mytm), buf); 1512 } 1513 1514 /* 1515 ** Adapted from code provided by Robert Elz, who writes: 1516 ** The "best" way to do mktime I think is based on an idea of Bob 1517 ** Kridle's (so its said...) from a long time ago. 1518 ** It does a binary search of the time_t space. Since time_t's are 1519 ** just 32 bits, its a max of 32 iterations (even at 64 bits it 1520 ** would still be very reasonable). 1521 */ 1522 1523 #ifndef WRONG 1524 #define WRONG (-1) 1525 #endif /* !defined WRONG */ 1526 1527 /* 1528 ** Normalize logic courtesy Paul Eggert. 1529 */ 1530 1531 static int 1532 increment_overflow(int *ip, int j) 1533 { 1534 int const i = *ip; 1535 1536 /* 1537 ** If i >= 0 there can only be overflow if i + j > INT_MAX 1538 ** or if j > INT_MAX - i; given i >= 0, INT_MAX - i cannot overflow. 1539 ** If i < 0 there can only be overflow if i + j < INT_MIN 1540 ** or if j < INT_MIN - i; given i < 0, INT_MIN - i cannot overflow. 1541 */ 1542 if ((i >= 0) ? (j > INT_MAX - i) : (j < INT_MIN - i)) 1543 return TRUE; 1544 *ip += j; 1545 return FALSE; 1546 } 1547 1548 static int 1549 long_increment_overflow(long *lp, int m) 1550 { 1551 long const l = *lp; 1552 1553 if ((l >= 0) ? (m > LONG_MAX - l) : (m < LONG_MIN - l)) 1554 return TRUE; 1555 *lp += m; 1556 return FALSE; 1557 } 1558 1559 static int 1560 normalize_overflow(int *tensptr, int *unitsptr, int base) 1561 { 1562 int tensdelta; 1563 1564 tensdelta = (*unitsptr >= 0) ? 1565 (*unitsptr / base) : 1566 (-1 - (-1 - *unitsptr) / base); 1567 *unitsptr -= tensdelta * base; 1568 return increment_overflow(tensptr, tensdelta); 1569 } 1570 1571 static int 1572 long_normalize_overflow(long *tensptr, int *unitsptr, int base) 1573 { 1574 int tensdelta; 1575 1576 tensdelta = (*unitsptr >= 0) ? 1577 (*unitsptr / base) : 1578 (-1 - (-1 - *unitsptr) / base); 1579 *unitsptr -= tensdelta * base; 1580 return long_increment_overflow(tensptr, tensdelta); 1581 } 1582 1583 static int 1584 tmcomp(const struct tm *atmp, const struct tm *btmp) 1585 { 1586 int result; 1587 1588 if ((result = (atmp->tm_year - btmp->tm_year)) == 0 && 1589 (result = (atmp->tm_mon - btmp->tm_mon)) == 0 && 1590 (result = (atmp->tm_mday - btmp->tm_mday)) == 0 && 1591 (result = (atmp->tm_hour - btmp->tm_hour)) == 0 && 1592 (result = (atmp->tm_min - btmp->tm_min)) == 0) 1593 result = atmp->tm_sec - btmp->tm_sec; 1594 return result; 1595 } 1596 1597 static time_t 1598 time2sub(struct tm *tmp, struct tm *(*funcp)(const time_t *, long, struct tm *), 1599 long offset, int *okayp, int do_norm_secs) 1600 { 1601 const struct state * sp; 1602 int dir; 1603 int i, j; 1604 int saved_seconds; 1605 long li; 1606 time_t lo; 1607 time_t hi; 1608 long y; 1609 time_t newt; 1610 time_t t; 1611 struct tm yourtm, mytm; 1612 1613 *okayp = FALSE; 1614 yourtm = *tmp; 1615 if (do_norm_secs) { 1616 if (normalize_overflow(&yourtm.tm_min, &yourtm.tm_sec, 1617 SECSPERMIN)) 1618 return WRONG; 1619 } 1620 if (normalize_overflow(&yourtm.tm_hour, &yourtm.tm_min, MINSPERHOUR)) 1621 return WRONG; 1622 if (normalize_overflow(&yourtm.tm_mday, &yourtm.tm_hour, HOURSPERDAY)) 1623 return WRONG; 1624 y = yourtm.tm_year; 1625 if (long_normalize_overflow(&y, &yourtm.tm_mon, MONSPERYEAR)) 1626 return WRONG; 1627 /* 1628 ** Turn y into an actual year number for now. 1629 ** It is converted back to an offset from TM_YEAR_BASE later. 1630 */ 1631 if (long_increment_overflow(&y, TM_YEAR_BASE)) 1632 return WRONG; 1633 while (yourtm.tm_mday <= 0) { 1634 if (long_increment_overflow(&y, -1)) 1635 return WRONG; 1636 li = y + (1 < yourtm.tm_mon); 1637 yourtm.tm_mday += year_lengths[isleap(li)]; 1638 } 1639 while (yourtm.tm_mday > DAYSPERLYEAR) { 1640 li = y + (1 < yourtm.tm_mon); 1641 yourtm.tm_mday -= year_lengths[isleap(li)]; 1642 if (long_increment_overflow(&y, 1)) 1643 return WRONG; 1644 } 1645 for ( ; ; ) { 1646 i = mon_lengths[isleap(y)][yourtm.tm_mon]; 1647 if (yourtm.tm_mday <= i) 1648 break; 1649 yourtm.tm_mday -= i; 1650 if (++yourtm.tm_mon >= MONSPERYEAR) { 1651 yourtm.tm_mon = 0; 1652 if (long_increment_overflow(&y, 1)) 1653 return WRONG; 1654 } 1655 } 1656 if (long_increment_overflow(&y, -TM_YEAR_BASE)) 1657 return WRONG; 1658 yourtm.tm_year = y; 1659 if (yourtm.tm_year != y) 1660 return WRONG; 1661 if (yourtm.tm_sec >= 0 && yourtm.tm_sec < SECSPERMIN) 1662 saved_seconds = 0; 1663 else if (y + TM_YEAR_BASE < EPOCH_YEAR) { 1664 /* 1665 ** We can't set tm_sec to 0, because that might push the 1666 ** time below the minimum representable time. 1667 ** Set tm_sec to 59 instead. 1668 ** This assumes that the minimum representable time is 1669 ** not in the same minute that a leap second was deleted from, 1670 ** which is a safer assumption than using 58 would be. 1671 */ 1672 if (increment_overflow(&yourtm.tm_sec, 1 - SECSPERMIN)) 1673 return WRONG; 1674 saved_seconds = yourtm.tm_sec; 1675 yourtm.tm_sec = SECSPERMIN - 1; 1676 } else { 1677 saved_seconds = yourtm.tm_sec; 1678 yourtm.tm_sec = 0; 1679 } 1680 /* 1681 ** Do a binary search (this works whatever time_t's type is). 1682 */ 1683 lo = 1; 1684 for (i = 0; i < (int) TYPE_BIT(time_t) - 1; ++i) 1685 lo *= 2; 1686 hi = -(lo + 1); 1687 for ( ; ; ) { 1688 t = lo / 2 + hi / 2; 1689 if (t < lo) 1690 t = lo; 1691 else if (t > hi) 1692 t = hi; 1693 if ((*funcp)(&t, offset, &mytm) == NULL) { 1694 /* 1695 ** Assume that t is too extreme to be represented in 1696 ** a struct tm; arrange things so that it is less 1697 ** extreme on the next pass. 1698 */ 1699 dir = (t > 0) ? 1 : -1; 1700 } else 1701 dir = tmcomp(&mytm, &yourtm); 1702 if (dir != 0) { 1703 if (t == lo) { 1704 ++t; 1705 if (t <= lo) 1706 return WRONG; 1707 ++lo; 1708 } else if (t == hi) { 1709 --t; 1710 if (t >= hi) 1711 return WRONG; 1712 --hi; 1713 } 1714 if (lo > hi) 1715 return WRONG; 1716 if (dir > 0) 1717 hi = t; 1718 else 1719 lo = t; 1720 continue; 1721 } 1722 if (yourtm.tm_isdst < 0 || mytm.tm_isdst == yourtm.tm_isdst) 1723 break; 1724 /* 1725 ** Right time, wrong type. 1726 ** Hunt for right time, right type. 1727 ** It's okay to guess wrong since the guess 1728 ** gets checked. 1729 */ 1730 sp = (const struct state *) 1731 ((funcp == localsub) ? lclptr : gmtptr); 1732 if (sp == NULL) 1733 return WRONG; 1734 for (i = sp->typecnt - 1; i >= 0; --i) { 1735 if (sp->ttis[i].tt_isdst != yourtm.tm_isdst) 1736 continue; 1737 for (j = sp->typecnt - 1; j >= 0; --j) { 1738 if (sp->ttis[j].tt_isdst == yourtm.tm_isdst) 1739 continue; 1740 newt = t + sp->ttis[j].tt_gmtoff - 1741 sp->ttis[i].tt_gmtoff; 1742 if ((*funcp)(&newt, offset, &mytm) == NULL) 1743 continue; 1744 if (tmcomp(&mytm, &yourtm) != 0) 1745 continue; 1746 if (mytm.tm_isdst != yourtm.tm_isdst) 1747 continue; 1748 /* 1749 ** We have a match. 1750 */ 1751 t = newt; 1752 goto label; 1753 } 1754 } 1755 return WRONG; 1756 } 1757 label: 1758 newt = t + saved_seconds; 1759 if ((newt < t) != (saved_seconds < 0)) 1760 return WRONG; 1761 t = newt; 1762 if ((*funcp)(&t, offset, tmp)) 1763 *okayp = TRUE; 1764 return t; 1765 } 1766 1767 static time_t 1768 time2(struct tm *tmp, struct tm * (*funcp)(const time_t *, long, struct tm *), 1769 long offset, int *okayp) 1770 { 1771 time_t t; 1772 1773 /* 1774 ** First try without normalization of seconds 1775 ** (in case tm_sec contains a value associated with a leap second). 1776 ** If that fails, try with normalization of seconds. 1777 */ 1778 t = time2sub(tmp, funcp, offset, okayp, FALSE); 1779 return *okayp ? t : time2sub(tmp, funcp, offset, okayp, TRUE); 1780 } 1781 1782 static time_t 1783 time1(struct tm *tmp, struct tm * (*funcp)(const time_t *, long, struct tm *), 1784 long offset) 1785 { 1786 time_t t; 1787 const struct state * sp; 1788 int samei, otheri; 1789 int sameind, otherind; 1790 int i; 1791 int nseen; 1792 int seen[TZ_MAX_TYPES]; 1793 int types[TZ_MAX_TYPES]; 1794 int okay; 1795 1796 if (tmp == NULL) { 1797 errno = EINVAL; 1798 return WRONG; 1799 } 1800 if (tmp->tm_isdst > 1) 1801 tmp->tm_isdst = 1; 1802 t = time2(tmp, funcp, offset, &okay); 1803 #ifdef PCTS 1804 /* 1805 ** PCTS code courtesy Grant Sullivan. 1806 */ 1807 if (okay) 1808 return t; 1809 if (tmp->tm_isdst < 0) 1810 tmp->tm_isdst = 0; /* reset to std and try again */ 1811 #endif /* defined PCTS */ 1812 #ifndef PCTS 1813 if (okay || tmp->tm_isdst < 0) 1814 return t; 1815 #endif /* !defined PCTS */ 1816 /* 1817 ** We're supposed to assume that somebody took a time of one type 1818 ** and did some math on it that yielded a "struct tm" that's bad. 1819 ** We try to divine the type they started from and adjust to the 1820 ** type they need. 1821 */ 1822 sp = (const struct state *) ((funcp == localsub) ? lclptr : gmtptr); 1823 if (sp == NULL) 1824 return WRONG; 1825 for (i = 0; i < sp->typecnt; ++i) 1826 seen[i] = FALSE; 1827 nseen = 0; 1828 for (i = sp->timecnt - 1; i >= 0; --i) { 1829 if (!seen[sp->types[i]]) { 1830 seen[sp->types[i]] = TRUE; 1831 types[nseen++] = sp->types[i]; 1832 } 1833 } 1834 for (sameind = 0; sameind < nseen; ++sameind) { 1835 samei = types[sameind]; 1836 if (sp->ttis[samei].tt_isdst != tmp->tm_isdst) 1837 continue; 1838 for (otherind = 0; otherind < nseen; ++otherind) { 1839 otheri = types[otherind]; 1840 if (sp->ttis[otheri].tt_isdst == tmp->tm_isdst) 1841 continue; 1842 tmp->tm_sec += sp->ttis[otheri].tt_gmtoff - 1843 sp->ttis[samei].tt_gmtoff; 1844 tmp->tm_isdst = !tmp->tm_isdst; 1845 t = time2(tmp, funcp, offset, &okay); 1846 if (okay) 1847 return t; 1848 tmp->tm_sec -= sp->ttis[otheri].tt_gmtoff - 1849 sp->ttis[samei].tt_gmtoff; 1850 tmp->tm_isdst = !tmp->tm_isdst; 1851 } 1852 } 1853 return WRONG; 1854 } 1855 1856 time_t 1857 mktime(struct tm *tmp) 1858 { 1859 time_t ret; 1860 1861 _THREAD_PRIVATE_MUTEX_LOCK(lcl); 1862 tzset_basic(); 1863 ret = time1(tmp, localsub, 0L); 1864 _THREAD_PRIVATE_MUTEX_UNLOCK(lcl); 1865 return ret; 1866 } 1867 DEF_STRONG(mktime); 1868 1869 #ifdef STD_INSPIRED 1870 1871 time_t 1872 timelocal(struct tm *tmp) 1873 { 1874 if (tmp != NULL) 1875 tmp->tm_isdst = -1; /* in case it wasn't initialized */ 1876 return mktime(tmp); 1877 } 1878 1879 time_t 1880 timegm(struct tm *tmp) 1881 { 1882 if (tmp != NULL) 1883 tmp->tm_isdst = 0; 1884 return time1(tmp, gmtsub, 0L); 1885 } 1886 1887 time_t 1888 timeoff(struct tm *tmp, long offset) 1889 { 1890 if (tmp != NULL) 1891 tmp->tm_isdst = 0; 1892 return time1(tmp, gmtsub, offset); 1893 } 1894 1895 #endif /* defined STD_INSPIRED */ 1896 1897 /* 1898 ** XXX--is the below the right way to conditionalize?? 1899 */ 1900 1901 #ifdef STD_INSPIRED 1902 1903 /* 1904 ** IEEE Std 1003.1-1988 (POSIX) legislates that 536457599 1905 ** shall correspond to "Wed Dec 31 23:59:59 UTC 1986", which 1906 ** is not the case if we are accounting for leap seconds. 1907 ** So, we provide the following conversion routines for use 1908 ** when exchanging timestamps with POSIX conforming systems. 1909 */ 1910 1911 static long 1912 leapcorr(time_t *timep) 1913 { 1914 struct state * sp; 1915 struct lsinfo * lp; 1916 int i; 1917 1918 sp = lclptr; 1919 i = sp->leapcnt; 1920 while (--i >= 0) { 1921 lp = &sp->lsis[i]; 1922 if (*timep >= lp->ls_trans) 1923 return lp->ls_corr; 1924 } 1925 return 0; 1926 } 1927 1928 time_t 1929 time2posix(time_t t) 1930 { 1931 tzset(); 1932 return t - leapcorr(&t); 1933 } 1934 1935 time_t 1936 posix2time(time_t t) 1937 { 1938 time_t x; 1939 time_t y; 1940 1941 tzset(); 1942 /* 1943 ** For a positive leap second hit, the result 1944 ** is not unique. For a negative leap second 1945 ** hit, the corresponding time doesn't exist, 1946 ** so we return an adjacent second. 1947 */ 1948 x = t + leapcorr(&t); 1949 y = x - leapcorr(&x); 1950 if (y < t) { 1951 do { 1952 x++; 1953 y = x - leapcorr(&x); 1954 } while (y < t); 1955 if (t != y) 1956 return x - 1; 1957 } else if (y > t) { 1958 do { 1959 --x; 1960 y = x - leapcorr(&x); 1961 } while (y > t); 1962 if (t != y) 1963 return x + 1; 1964 } 1965 return x; 1966 } 1967 1968 #endif /* defined STD_INSPIRED */ 1969