lib/libc/stdtime/localtime.c

   1 /*
   2 ** This file is in the public domain, so clarified as of
   3 ** 1996-06-05 by Arthur David Olson (arthur_david_olson@nih.gov).
   4 */
   5
   6 #include <sys/cdefs.h>
   7 #ifndef lint
   8 #ifndef NOID
   9 static char     elsieid[] __unused = "@(#)localtime.c   7.78";
  10 #endif /* !defined NOID */
  11 #endif /* !defined lint */
  12 __FBSDID("$FreeBSD$");
  13
  14 /*
  15 ** Leap second handling from Bradley White (bww@k.gp.cs.cmu.edu).
  16 ** POSIX-style TZ environment variable handling from Guy Harris
  17 ** (guy@auspex.com).
  18 */
  19
  20 /*LINTLIBRARY*/
  21
  22 #include "namespace.h"
  23 #include <sys/types.h>
  24 #include <sys/stat.h>
  25 #include <fcntl.h>
  26 #include <pthread.h>
  27 #include "private.h"
  28 #include "un-namespace.h"
  29
  30 #include "tzfile.h"
  31
  32 #include "libc_private.h"
  33
  34 #define _MUTEX_LOCK(x)          if (__isthreaded) _pthread_mutex_lock(x)
  35 #define _MUTEX_UNLOCK(x)        if (__isthreaded) _pthread_mutex_unlock(x)
  36
  37 #define _RWLOCK_RDLOCK(x)                                               \
  38                 do {                                                    \
  39                         if (__isthreaded) _pthread_rwlock_rdlock(x);    \
  40                 } while (0)
  41
  42 #define _RWLOCK_WRLOCK(x)                                               \
  43                 do {                                                    \
  44                         if (__isthreaded) _pthread_rwlock_wrlock(x);    \
  45                 } while (0)
  46
  47 #define _RWLOCK_UNLOCK(x)                                               \
  48                 do {                                                    \
  49                         if (__isthreaded) _pthread_rwlock_unlock(x);    \
  50                 } while (0)
  51
  52 /*
  53 ** SunOS 4.1.1 headers lack O_BINARY.
  54 */
  55
  56 #ifdef O_BINARY
  57 #define OPEN_MODE       (O_RDONLY | O_BINARY)
  58 #endif /* defined O_BINARY */
  59 #ifndef O_BINARY
  60 #define OPEN_MODE       O_RDONLY
  61 #endif /* !defined O_BINARY */
  62
  63 #ifndef WILDABBR
  64 /*
  65 ** Someone might make incorrect use of a time zone abbreviation:
  66 **      1.      They might reference tzname[0] before calling tzset (explicitly
  67 **              or implicitly).
  68 **      2.      They might reference tzname[1] before calling tzset (explicitly
  69 **              or implicitly).
  70 **      3.      They might reference tzname[1] after setting to a time zone
  71 **              in which Daylight Saving Time is never observed.
  72 **      4.      They might reference tzname[0] after setting to a time zone
  73 **              in which Standard Time is never observed.
  74 **      5.      They might reference tm.TM_ZONE after calling offtime.
  75 ** What's best to do in the above cases is open to debate;
  76 ** for now, we just set things up so that in any of the five cases
  77 ** WILDABBR is used.  Another possibility:  initialize tzname[0] to the
  78 ** string "tzname[0] used before set", and similarly for the other cases.
  79 ** And another:  initialize tzname[0] to "ERA", with an explanation in the
  80 ** manual page of what this "time zone abbreviation" means (doing this so
  81 ** that tzname[0] has the "normal" length of three characters).
  82 */
  83 #define WILDABBR        "   "
  84 #endif /* !defined WILDABBR */
  85
  86 static char             wildabbr[] = "WILDABBR";
  87
  88 /*
  89  * In June 2004 it was decided UTC was a more appropriate default time
  90  * zone than GMT.
  91  */
  92
  93 static const char       gmt[] = "UTC";
  94
  95 /*
  96 ** The DST rules to use if TZ has no rules and we can't load TZDEFRULES.
  97 ** We default to US rules as of 1999-08-17.
  98 ** POSIX 1003.1 section 8.1.1 says that the default DST rules are
  99 ** implementation dependent; for historical reasons, US rules are a
 100 ** common default.
 101 */
 102 #ifndef TZDEFRULESTRING
 103 #define TZDEFRULESTRING ",M4.1.0,M10.5.0"
 104 #endif /* !defined TZDEFDST */
 105
 106 struct ttinfo {                         /* time type information */
 107         long            tt_gmtoff;      /* UTC offset in seconds */
 108         int             tt_isdst;       /* used to set tm_isdst */
 109         int             tt_abbrind;     /* abbreviation list index */
 110         int             tt_ttisstd;     /* TRUE if transition is std time */
 111         int             tt_ttisgmt;     /* TRUE if transition is UTC */
 112 };
 113
 114 struct lsinfo {                         /* leap second information */
 115         time_t          ls_trans;       /* transition time */
 116         long            ls_corr;        /* correction to apply */
 117 };
 118
 119 #define BIGGEST(a, b)   (((a) > (b)) ? (a) : (b))
 120
 121 #ifdef TZNAME_MAX
 122 #define MY_TZNAME_MAX   TZNAME_MAX
 123 #endif /* defined TZNAME_MAX */
 124 #ifndef TZNAME_MAX
 125 #define MY_TZNAME_MAX   255
 126 #endif /* !defined TZNAME_MAX */
 127
 128 struct state {
 129         int             leapcnt;
 130         int             timecnt;
 131         int             typecnt;
 132         int             charcnt;
 133         time_t          ats[TZ_MAX_TIMES];
 134         unsigned char   types[TZ_MAX_TIMES];
 135         struct ttinfo   ttis[TZ_MAX_TYPES];
 136         char            chars[BIGGEST(BIGGEST(TZ_MAX_CHARS + 1, sizeof gmt),
 137                                 (2 * (MY_TZNAME_MAX + 1)))];
 138         struct lsinfo   lsis[TZ_MAX_LEAPS];
 139 };
 140
 141 struct rule {
 142         int             r_type;         /* type of rule--see below */
 143         int             r_day;          /* day number of rule */
 144         int             r_week;         /* week number of rule */
 145         int             r_mon;          /* month number of rule */
 146         long            r_time;         /* transition time of rule */
 147 };
 148
 149 #define JULIAN_DAY              0       /* Jn - Julian day */
 150 #define DAY_OF_YEAR             1       /* n - day of year */
 151 #define MONTH_NTH_DAY_OF_WEEK   2       /* Mm.n.d - month, week, day of week */
 152
 153 /*
 154 ** Prototypes for static functions.
 155 */
 156
 157 static long             detzcode(const char * codep);
 158 static const char *     getzname(const char * strp);
 159 static const char *     getnum(const char * strp, int * nump, int min,
 160                                 int max);
 161 static const char *     getsecs(const char * strp, long * secsp);
 162 static const char *     getoffset(const char * strp, long * offsetp);
 163 static const char *     getrule(const char * strp, struct rule * rulep);
 164 static void             gmtload(struct state * sp);
 165 static void             gmtsub(const time_t * timep, long offset,
 166                                 struct tm * tmp);
 167 static void             localsub(const time_t * timep, long offset,
 168                                 struct tm * tmp);
 169 static int              increment_overflow(int * number, int delta);
 170 static int              normalize_overflow(int * tensptr, int * unitsptr,
 171                                 int base);
 172 static void             settzname(void);
 173 static time_t           time1(struct tm * tmp,
 174                                 void(*funcp) (const time_t *,
 175                                 long, struct tm *),
 176                                 long offset);
 177 static time_t           time2(struct tm *tmp,
 178                                 void(*funcp) (const time_t *,
 179                                 long, struct tm*),
 180                                 long offset, int * okayp);
 181 static time_t           time2sub(struct tm *tmp,
 182                                 void(*funcp) (const time_t *,
 183                                 long, struct tm*),
 184                                 long offset, int * okayp, int do_norm_secs);
 185 static void             timesub(const time_t * timep, long offset,
 186                                 const struct state * sp, struct tm * tmp);
 187 static int              tmcomp(const struct tm * atmp,
 188                                 const struct tm * btmp);
 189 static time_t           transtime(time_t janfirst, int year,
 190                                 const struct rule * rulep, long offset);
 191 static int              tzload(const char * name, struct state * sp);
 192 static int              tzparse(const char * name, struct state * sp,
 193                                 int lastditch);
 194
 195 #ifdef ALL_STATE
 196 static struct state *   lclptr;
 197 static struct state *   gmtptr;
 198 #endif /* defined ALL_STATE */
 199
 200 #ifndef ALL_STATE
 201 static struct state     lclmem;
 202 static struct state     gmtmem;
 203 #define lclptr          (&lclmem)
 204 #define gmtptr          (&gmtmem)
 205 #endif /* State Farm */
 206
 207 #ifndef TZ_STRLEN_MAX
 208 #define TZ_STRLEN_MAX 255
 209 #endif /* !defined TZ_STRLEN_MAX */
 210
 211 static char             lcl_TZname[TZ_STRLEN_MAX + 1];
 212 static int              lcl_is_set;
 213 static int              gmt_is_set;
 214 static pthread_rwlock_t lcl_rwlock = PTHREAD_RWLOCK_INITIALIZER;
 215 static pthread_mutex_t  gmt_mutex = PTHREAD_MUTEX_INITIALIZER;
 216
 217 char *                  tzname[2] = {
 218         wildabbr,
 219         wildabbr
 220 };
 221
 222 /*
 223 ** Section 4.12.3 of X3.159-1989 requires that
 224 **      Except for the strftime function, these functions [asctime,
 225 **      ctime, gmtime, localtime] return values in one of two static
 226 **      objects: a broken-down time structure and an array of char.
 227 ** Thanks to Paul Eggert (eggert@twinsun.com) for noting this.
 228 */
 229
 230 static struct tm        tm;
 231
 232 #ifdef USG_COMPAT
 233 time_t                  timezone = 0;
 234 int                     daylight = 0;
 235 #endif /* defined USG_COMPAT */
 236
 237 #ifdef ALTZONE
 238 time_t                  altzone = 0;
 239 #endif /* defined ALTZONE */
 240
 241 static long
 242 detzcode(codep)
 243 const char * const      codep;
 244 {
 245         long    result;
 246         int     i;
 247
 248         result = (codep[0] & 0x80) ? ~0L : 0L;
 249         for (i = 0; i < 4; ++i)
 250                 result = (result << 8) | (codep[i] & 0xff);
 251         return result;
 252 }
 253
 254 static void
 255 settzname(void)
 256 {
 257         struct state *  sp = lclptr;
 258         int                     i;
 259
 260         tzname[0] = wildabbr;
 261         tzname[1] = wildabbr;
 262 #ifdef USG_COMPAT
 263         daylight = 0;
 264         timezone = 0;
 265 #endif /* defined USG_COMPAT */
 266 #ifdef ALTZONE
 267         altzone = 0;
 268 #endif /* defined ALTZONE */
 269 #ifdef ALL_STATE
 270         if (sp == NULL) {
 271                 tzname[0] = tzname[1] = gmt;
 272                 return;
 273         }
 274 #endif /* defined ALL_STATE */
 275         for (i = 0; i < sp->typecnt; ++i) {
 276                 const struct ttinfo * const     ttisp = &sp->ttis[i];
 277
 278                 tzname[ttisp->tt_isdst] =
 279                         &sp->chars[ttisp->tt_abbrind];
 280 #ifdef USG_COMPAT
 281                 if (ttisp->tt_isdst)
 282                         daylight = 1;
 283                 if (i == 0 || !ttisp->tt_isdst)
 284                         timezone = -(ttisp->tt_gmtoff);
 285 #endif /* defined USG_COMPAT */
 286 #ifdef ALTZONE
 287                 if (i == 0 || ttisp->tt_isdst)
 288                         altzone = -(ttisp->tt_gmtoff);
 289 #endif /* defined ALTZONE */
 290         }
 291         /*
 292         ** And to get the latest zone names into tzname. . .
 293         */
 294         for (i = 0; i < sp->timecnt; ++i) {
 295                 const struct ttinfo * const     ttisp =
 296                                                         &sp->ttis[
 297                                                                 sp->types[i]];
 298
 299                 tzname[ttisp->tt_isdst] =
 300                         &sp->chars[ttisp->tt_abbrind];
 301         }
 302 }
 303
 304 static int
 305 tzload(name, sp)
 306 const char *            name;
 307 struct state * const    sp;
 308 {
 309         const char *    p;
 310         int             i;
 311         int             fid;
 312
 313         /* XXX The following is from OpenBSD, and I'm not sure it is correct */
 314         if (name != NULL && issetugid() != 0)
 315                 if ((name[0] == ':' && name[1] == '/') ||
 316                     name[0] == '/' || strchr(name, '.'))
 317                         name = NULL;
 318         if (name == NULL && (name = TZDEFAULT) == NULL)
 319                 return -1;
 320         {
 321                 int     doaccess;
 322                 struct stat     stab;
 323                 /*
 324                 ** Section 4.9.1 of the C standard says that
 325                 ** "FILENAME_MAX expands to an integral constant expression
 326                 ** that is the size needed for an array of char large enough
 327                 ** to hold the longest file name string that the implementation
 328                 ** guarantees can be opened."
 329                 */
 330                 char            fullname[FILENAME_MAX + 1];
 331
 332                 if (name[0] == ':')
 333                         ++name;
 334                 doaccess = name[0] == '/';
 335                 if (!doaccess) {
 336                         if ((p = TZDIR) == NULL)
 337                                 return -1;
 338                         if ((strlen(p) + 1 + strlen(name) + 1) >= sizeof fullname)
 339                                 return -1;
 340                         (void) strcpy(fullname, p);
 341                         (void) strcat(fullname, "/");
 342                         (void) strcat(fullname, name);
 343                         /*
 344                         ** Set doaccess if '.' (as in "../") shows up in name.
 345                         */
 346                         if (strchr(name, '.') != NULL)
 347                                 doaccess = TRUE;
 348                         name = fullname;
 349                 }
 350                 if (doaccess && access(name, R_OK) != 0)
 351                         return -1;
 352                 if ((fid = _open(name, OPEN_MODE)) == -1)
 353                         return -1;
 354                 if ((_fstat(fid, &stab) < 0) || !S_ISREG(stab.st_mode)) {
 355                         _close(fid);
 356                         return -1;
 357                 }
 358         }
 359         {
 360                 struct tzhead * tzhp;
 361                 union {
 362                         struct tzhead   tzhead;
 363                         char            buf[sizeof *sp + sizeof *tzhp];
 364                 } u;
 365                 int             ttisstdcnt;
 366                 int             ttisgmtcnt;
 367
 368                 i = _read(fid, u.buf, sizeof u.buf);
 369                 if (_close(fid) != 0)
 370                         return -1;
 371                 ttisstdcnt = (int) detzcode(u.tzhead.tzh_ttisstdcnt);
 372                 ttisgmtcnt = (int) detzcode(u.tzhead.tzh_ttisgmtcnt);
 373                 sp->leapcnt = (int) detzcode(u.tzhead.tzh_leapcnt);
 374                 sp->timecnt = (int) detzcode(u.tzhead.tzh_timecnt);
 375                 sp->typecnt = (int) detzcode(u.tzhead.tzh_typecnt);
 376                 sp->charcnt = (int) detzcode(u.tzhead.tzh_charcnt);
 377                 p = u.tzhead.tzh_charcnt + sizeof u.tzhead.tzh_charcnt;
 378                 if (sp->leapcnt < 0 || sp->leapcnt > TZ_MAX_LEAPS ||
 379                         sp->typecnt <= 0 || sp->typecnt > TZ_MAX_TYPES ||
 380                         sp->timecnt < 0 || sp->timecnt > TZ_MAX_TIMES ||
 381                         sp->charcnt < 0 || sp->charcnt > TZ_MAX_CHARS ||
 382                         (ttisstdcnt != sp->typecnt && ttisstdcnt != 0) ||
 383                         (ttisgmtcnt != sp->typecnt && ttisgmtcnt != 0))
 384                                 return -1;
 385                 if (i - (p - u.buf) < sp->timecnt * 4 + /* ats */
 386                         sp->timecnt +                   /* types */
 387                         sp->typecnt * (4 + 2) +         /* ttinfos */
 388                         sp->charcnt +                   /* chars */
 389                         sp->leapcnt * (4 + 4) +         /* lsinfos */
 390                         ttisstdcnt +                    /* ttisstds */
 391                         ttisgmtcnt)                     /* ttisgmts */
 392                                 return -1;
 393                 for (i = 0; i < sp->timecnt; ++i) {
 394                         sp->ats[i] = detzcode(p);
 395                         p += 4;
 396                 }
 397                 for (i = 0; i < sp->timecnt; ++i) {
 398                         sp->types[i] = (unsigned char) *p++;
 399                         if (sp->types[i] >= sp->typecnt)
 400                                 return -1;
 401                 }
 402                 for (i = 0; i < sp->typecnt; ++i) {
 403                         struct ttinfo * ttisp;
 404
 405                         ttisp = &sp->ttis[i];
 406                         ttisp->tt_gmtoff = detzcode(p);
 407                         p += 4;
 408                         ttisp->tt_isdst = (unsigned char) *p++;
 409                         if (ttisp->tt_isdst != 0 && ttisp->tt_isdst != 1)
 410                                 return -1;
 411                         ttisp->tt_abbrind = (unsigned char) *p++;
 412                         if (ttisp->tt_abbrind < 0 ||
 413                                 ttisp->tt_abbrind > sp->charcnt)
 414                                         return -1;
 415                 }
 416                 for (i = 0; i < sp->charcnt; ++i)
 417                         sp->chars[i] = *p++;
 418                 sp->chars[i] = '\0';    /* ensure '\0' at end */
 419                 for (i = 0; i < sp->leapcnt; ++i) {
 420                         struct lsinfo * lsisp;
 421
 422                         lsisp = &sp->lsis[i];
 423                         lsisp->ls_trans = detzcode(p);
 424                         p += 4;
 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                                                 return -1;
 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                                                 return -1;
 452                         }
 453                 }
 454         }
 455         return 0;
 456 }
 457
 458 static const int        mon_lengths[2][MONSPERYEAR] = {
 459         { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 },
 460         { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }
 461 };
 462
 463 static const int        year_lengths[2] = {
 464         DAYSPERNYEAR, DAYSPERLYEAR
 465 };
 466
 467 /*
 468 ** Given a pointer into a time zone string, scan until a character that is not
 469 ** a valid character in a zone name is found.  Return a pointer to that
 470 ** character.
 471 */
 472
 473 static const char *
 474 getzname(strp)
 475 const char *    strp;
 476 {
 477         char    c;
 478
 479         while ((c = *strp) != '\0' && !is_digit(c) && c != ',' && c != '-' &&
 480                 c != '+')
 481                         ++strp;
 482         return strp;
 483 }
 484
 485 /*
 486 ** Given a pointer into a time zone string, extract a number from that string.
 487 ** Check that the number is within a specified range; if it is not, return
 488 ** NULL.
 489 ** Otherwise, return a pointer to the first character not part of the number.
 490 */
 491
 492 static const char *
 493 getnum(strp, nump, min, max)
 494 const char *    strp;
 495 int * const             nump;
 496 const int               min;
 497 const int               max;
 498 {
 499         char    c;
 500         int     num;
 501
 502         if (strp == NULL || !is_digit(c = *strp))
 503                 return NULL;
 504         num = 0;
 505         do {
 506                 num = num * 10 + (c - '0');
 507                 if (num > max)
 508                         return NULL;    /* illegal value */
 509                 c = *++strp;
 510         } while (is_digit(c));
 511         if (num < min)
 512                 return NULL;            /* illegal value */
 513         *nump = num;
 514         return strp;
 515 }
 516
 517 /*
 518 ** Given a pointer into a time zone string, extract a number of seconds,
 519 ** in hh[:mm[:ss]] form, from the string.
 520 ** If any error occurs, return NULL.
 521 ** Otherwise, return a pointer to the first character not part of the number
 522 ** of seconds.
 523 */
 524
 525 static const char *
 526 getsecs(strp, secsp)
 527 const char *    strp;
 528 long * const            secsp;
 529 {
 530         int     num;
 531
 532         /*
 533         ** `HOURSPERDAY * DAYSPERWEEK - 1' allows quasi-Posix rules like
 534         ** "M10.4.6/26", which does not conform to Posix,
 535         ** but which specifies the equivalent of
 536         ** ``02:00 on the first Sunday on or after 23 Oct''.
 537         */
 538         strp = getnum(strp, &num, 0, HOURSPERDAY * DAYSPERWEEK - 1);
 539         if (strp == NULL)
 540                 return NULL;
 541         *secsp = num * (long) SECSPERHOUR;
 542         if (*strp == ':') {
 543                 ++strp;
 544                 strp = getnum(strp, &num, 0, MINSPERHOUR - 1);
 545                 if (strp == NULL)
 546                         return NULL;
 547                 *secsp += num * SECSPERMIN;
 548                 if (*strp == ':') {
 549                         ++strp;
 550                         /* `SECSPERMIN' allows for leap seconds.  */
 551                         strp = getnum(strp, &num, 0, SECSPERMIN);
 552                         if (strp == NULL)
 553                                 return NULL;
 554                         *secsp += num;
 555                 }
 556         }
 557         return strp;
 558 }
 559
 560 /*
 561 ** Given a pointer into a time zone string, extract an offset, in
 562 ** [+-]hh[:mm[:ss]] form, from the string.
 563 ** If any error occurs, return NULL.
 564 ** Otherwise, return a pointer to the first character not part of the time.
 565 */
 566
 567 static const char *
 568 getoffset(strp, offsetp)
 569 const char *    strp;
 570 long * const            offsetp;
 571 {
 572         int     neg = 0;
 573
 574         if (*strp == '-') {
 575                 neg = 1;
 576                 ++strp;
 577         } else if (*strp == '+')
 578                 ++strp;
 579         strp = getsecs(strp, offsetp);
 580         if (strp == NULL)
 581                 return NULL;            /* illegal time */
 582         if (neg)
 583                 *offsetp = -*offsetp;
 584         return strp;
 585 }
 586
 587 /*
 588 ** Given a pointer into a time zone string, extract a rule in the form
 589 ** date[/time].  See POSIX section 8 for the format of "date" and "time".
 590 ** If a valid rule is not found, return NULL.
 591 ** Otherwise, return a pointer to the first character not part of the rule.
 592 */
 593
 594 static const char *
 595 getrule(strp, rulep)
 596 const char *                    strp;
 597 struct rule * const     rulep;
 598 {
 599         if (*strp == 'J') {
 600                 /*
 601                 ** Julian day.
 602                 */
 603                 rulep->r_type = JULIAN_DAY;
 604                 ++strp;
 605                 strp = getnum(strp, &rulep->r_day, 1, DAYSPERNYEAR);
 606         } else if (*strp == 'M') {
 607                 /*
 608                 ** Month, week, day.
 609                 */
 610                 rulep->r_type = MONTH_NTH_DAY_OF_WEEK;
 611                 ++strp;
 612                 strp = getnum(strp, &rulep->r_mon, 1, MONSPERYEAR);
 613                 if (strp == NULL)
 614                         return NULL;
 615                 if (*strp++ != '.')
 616                         return NULL;
 617                 strp = getnum(strp, &rulep->r_week, 1, 5);
 618                 if (strp == NULL)
 619                         return NULL;
 620                 if (*strp++ != '.')
 621                         return NULL;
 622                 strp = getnum(strp, &rulep->r_day, 0, DAYSPERWEEK - 1);
 623         } else if (is_digit(*strp)) {
 624                 /*
 625                 ** Day of year.
 626                 */
 627                 rulep->r_type = DAY_OF_YEAR;
 628                 strp = getnum(strp, &rulep->r_day, 0, DAYSPERLYEAR - 1);
 629         } else  return NULL;            /* invalid format */
 630         if (strp == NULL)
 631                 return NULL;
 632         if (*strp == '/') {
 633                 /*
 634                 ** Time specified.
 635                 */
 636                 ++strp;
 637                 strp = getsecs(strp, &rulep->r_time);
 638         } else  rulep->r_time = 2 * SECSPERHOUR;        /* default = 2:00:00 */
 639         return strp;
 640 }
 641
 642 /*
 643 ** Given the Epoch-relative time of January 1, 00:00:00 UTC, in a year, the
 644 ** year, a rule, and the offset from UTC at the time that rule takes effect,
 645 ** calculate the Epoch-relative time that rule takes effect.
 646 */
 647
 648 static time_t
 649 transtime(janfirst, year, rulep, offset)
 650 const time_t                            janfirst;
 651 const int                               year;
 652 const struct rule * const       rulep;
 653 const long                              offset;
 654 {
 655         int     leapyear;
 656         time_t  value;
 657         int     i;
 658         int             d, m1, yy0, yy1, yy2, dow;
 659
 660         INITIALIZE(value);
 661         leapyear = isleap(year);
 662         switch (rulep->r_type) {
 663
 664         case JULIAN_DAY:
 665                 /*
 666                 ** Jn - Julian day, 1 == January 1, 60 == March 1 even in leap
 667                 ** years.
 668                 ** In non-leap years, or if the day number is 59 or less, just
 669                 ** add SECSPERDAY times the day number-1 to the time of
 670                 ** January 1, midnight, to get the day.
 671                 */
 672                 value = janfirst + (rulep->r_day - 1) * SECSPERDAY;
 673                 if (leapyear && rulep->r_day >= 60)
 674                         value += SECSPERDAY;
 675                 break;
 676
 677         case DAY_OF_YEAR:
 678                 /*
 679                 ** n - day of year.
 680                 ** Just add SECSPERDAY times the day number to the time of
 681                 ** January 1, midnight, to get the day.
 682                 */
 683                 value = janfirst + rulep->r_day * SECSPERDAY;
 684                 break;
 685
 686         case MONTH_NTH_DAY_OF_WEEK:
 687                 /*
 688                 ** Mm.n.d - nth "dth day" of month m.
 689                 */
 690                 value = janfirst;
 691                 for (i = 0; i < rulep->r_mon - 1; ++i)
 692                         value += mon_lengths[leapyear][i] * SECSPERDAY;
 693
 694                 /*
 695                 ** Use Zeller's Congruence to get day-of-week of first day of
 696                 ** month.
 697                 */
 698                 m1 = (rulep->r_mon + 9) % 12 + 1;
 699                 yy0 = (rulep->r_mon <= 2) ? (year - 1) : year;
 700                 yy1 = yy0 / 100;
 701                 yy2 = yy0 % 100;
 702                 dow = ((26 * m1 - 2) / 10 +
 703                         1 + yy2 + yy2 / 4 + yy1 / 4 - 2 * yy1) % 7;
 704                 if (dow < 0)
 705                         dow += DAYSPERWEEK;
 706
 707                 /*
 708                 ** "dow" is the day-of-week of the first day of the month.  Get
 709                 ** the day-of-month (zero-origin) of the first "dow" day of the
 710                 ** month.
 711                 */
 712                 d = rulep->r_day - dow;
 713                 if (d < 0)
 714                         d += DAYSPERWEEK;
 715                 for (i = 1; i < rulep->r_week; ++i) {
 716                         if (d + DAYSPERWEEK >=
 717                                 mon_lengths[leapyear][rulep->r_mon - 1])
 718                                         break;
 719                         d += DAYSPERWEEK;
 720                 }
 721
 722                 /*
 723                 ** "d" is the day-of-month (zero-origin) of the day we want.
 724                 */
 725                 value += d * SECSPERDAY;
 726                 break;
 727         }
 728
 729         /*
 730         ** "value" is the Epoch-relative time of 00:00:00 UTC on the day in
 731         ** question.  To get the Epoch-relative time of the specified local
 732         ** time on that day, add the transition time and the current offset
 733         ** from UTC.
 734         */
 735         return value + rulep->r_time + offset;
 736 }
 737
 738 /*
 739 ** Given a POSIX section 8-style TZ string, fill in the rule tables as
 740 ** appropriate.
 741 */
 742
 743 static int
 744 tzparse(name, sp, lastditch)
 745 const char *                    name;
 746 struct state * const    sp;
 747 const int                       lastditch;
 748 {
 749         const char *                    stdname;
 750         const char *                    dstname;
 751         size_t                          stdlen;
 752         size_t                          dstlen;
 753         long                            stdoffset;
 754         long                            dstoffset;
 755         time_t *                atp;
 756         unsigned char * typep;
 757         char *                  cp;
 758         int                     load_result;
 759
 760         INITIALIZE(dstname);
 761         stdname = name;
 762         if (lastditch) {
 763                 stdlen = strlen(name);  /* length of standard zone name */
 764                 name += stdlen;
 765                 if (stdlen >= sizeof sp->chars)
 766                         stdlen = (sizeof sp->chars) - 1;
 767                 stdoffset = 0;
 768         } else {
 769                 name = getzname(name);
 770                 stdlen = name - stdname;
 771                 if (stdlen < 3)
 772                         return -1;
 773                 if (*name == '\0')
 774                         return -1;      /* was "stdoffset = 0;" */
 775                 else {
 776                         name = getoffset(name, &stdoffset);
 777                         if (name == NULL)
 778                                 return -1;
 779                 }
 780         }
 781         load_result = tzload(TZDEFRULES, sp);
 782         if (load_result != 0)
 783                 sp->leapcnt = 0;                /* so, we're off a little */
 784         if (*name != '\0') {
 785                 dstname = name;
 786                 name = getzname(name);
 787                 dstlen = name - dstname;        /* length of DST zone name */
 788                 if (dstlen < 3)
 789                         return -1;
 790                 if (*name != '\0' && *name != ',' && *name != ';') {
 791                         name = getoffset(name, &dstoffset);
 792                         if (name == NULL)
 793                                 return -1;
 794                 } else  dstoffset = stdoffset - SECSPERHOUR;
 795                 if (*name == '\0' && load_result != 0)
 796                         name = TZDEFRULESTRING;
 797                 if (*name == ',' || *name == ';') {
 798                         struct rule     start;
 799                         struct rule     end;
 800                         int     year;
 801                         time_t  janfirst;
 802                         time_t          starttime;
 803                         time_t          endtime;
 804
 805                         ++name;
 806                         if ((name = getrule(name, &start)) == NULL)
 807                                 return -1;
 808                         if (*name++ != ',')
 809                                 return -1;
 810                         if ((name = getrule(name, &end)) == NULL)
 811                                 return -1;
 812                         if (*name != '\0')
 813                                 return -1;
 814                         sp->typecnt = 2;        /* standard time and DST */
 815                         /*
 816                         ** Two transitions per year, from EPOCH_YEAR to 2037.
 817                         */
 818                         sp->timecnt = 2 * (2037 - EPOCH_YEAR + 1);
 819                         if (sp->timecnt > TZ_MAX_TIMES)
 820                                 return -1;
 821                         sp->ttis[0].tt_gmtoff = -dstoffset;
 822                         sp->ttis[0].tt_isdst = 1;
 823                         sp->ttis[0].tt_abbrind = stdlen + 1;
 824                         sp->ttis[1].tt_gmtoff = -stdoffset;
 825                         sp->ttis[1].tt_isdst = 0;
 826                         sp->ttis[1].tt_abbrind = 0;
 827                         atp = sp->ats;
 828                         typep = sp->types;
 829                         janfirst = 0;
 830                         for (year = EPOCH_YEAR; year <= 2037; ++year) {
 831                                 starttime = transtime(janfirst, year, &start,
 832                                         stdoffset);
 833                                 endtime = transtime(janfirst, year, &end,
 834                                         dstoffset);
 835                                 if (starttime > endtime) {
 836                                         *atp++ = endtime;
 837                                         *typep++ = 1;   /* DST ends */
 838                                         *atp++ = starttime;
 839                                         *typep++ = 0;   /* DST begins */
 840                                 } else {
 841                                         *atp++ = starttime;
 842                                         *typep++ = 0;   /* DST begins */
 843                                         *atp++ = endtime;
 844                                         *typep++ = 1;   /* DST ends */
 845                                 }
 846                                 janfirst += year_lengths[isleap(year)] *
 847                                         SECSPERDAY;
 848                         }
 849                 } else {
 850                         long    theirstdoffset;
 851                         long    theirdstoffset;
 852                         long    theiroffset;
 853                         int     isdst;
 854                         int     i;
 855                         int     j;
 856
 857                         if (*name != '\0')
 858                                 return -1;
 859                         /*
 860                         ** Initial values of theirstdoffset and theirdstoffset.
 861                         */
 862                         theirstdoffset = 0;
 863                         for (i = 0; i < sp->timecnt; ++i) {
 864                                 j = sp->types[i];
 865                                 if (!sp->ttis[j].tt_isdst) {
 866                                         theirstdoffset =
 867                                                 -sp->ttis[j].tt_gmtoff;
 868                                         break;
 869                                 }
 870                         }
 871                         theirdstoffset = 0;
 872                         for (i = 0; i < sp->timecnt; ++i) {
 873                                 j = sp->types[i];
 874                                 if (sp->ttis[j].tt_isdst) {
 875                                         theirdstoffset =
 876                                                 -sp->ttis[j].tt_gmtoff;
 877                                         break;
 878                                 }
 879                         }
 880                         /*
 881                         ** Initially we're assumed to be in standard time.
 882                         */
 883                         isdst = FALSE;
 884                         theiroffset = theirstdoffset;
 885                         /*
 886                         ** Now juggle transition times and types
 887                         ** tracking offsets as you do.
 888                         */
 889                         for (i = 0; i < sp->timecnt; ++i) {
 890                                 j = sp->types[i];
 891                                 sp->types[i] = sp->ttis[j].tt_isdst;
 892                                 if (sp->ttis[j].tt_ttisgmt) {
 893                                         /* No adjustment to transition time */
 894                                 } else {
 895                                         /*
 896                                         ** If summer time is in effect, and the
 897                                         ** transition time was not specified as
 898                                         ** standard time, add the summer time
 899                                         ** offset to the transition time;
 900                                         ** otherwise, add the standard time
 901                                         ** offset to the transition time.
 902                                         */
 903                                         /*
 904                                         ** Transitions from DST to DDST
 905                                         ** will effectively disappear since
 906                                         ** POSIX provides for only one DST
 907                                         ** offset.
 908                                         */
 909                                         if (isdst && !sp->ttis[j].tt_ttisstd) {
 910                                                 sp->ats[i] += dstoffset -
 911                                                         theirdstoffset;
 912                                         } else {
 913                                                 sp->ats[i] += stdoffset -
 914                                                         theirstdoffset;
 915                                         }
 916                                 }
 917                                 theiroffset = -sp->ttis[j].tt_gmtoff;
 918                                 if (sp->ttis[j].tt_isdst)
 919                                         theirdstoffset = theiroffset;
 920                                 else    theirstdoffset = theiroffset;
 921                         }
 922                         /*
 923                         ** Finally, fill in ttis.
 924                         ** ttisstd and ttisgmt need not be handled.
 925                         */
 926                         sp->ttis[0].tt_gmtoff = -stdoffset;
 927                         sp->ttis[0].tt_isdst = FALSE;
 928                         sp->ttis[0].tt_abbrind = 0;
 929                         sp->ttis[1].tt_gmtoff = -dstoffset;
 930                         sp->ttis[1].tt_isdst = TRUE;
 931                         sp->ttis[1].tt_abbrind = stdlen + 1;
 932                         sp->typecnt = 2;
 933                 }
 934         } else {
 935                 dstlen = 0;
 936                 sp->typecnt = 1;                /* only standard time */
 937                 sp->timecnt = 0;
 938                 sp->ttis[0].tt_gmtoff = -stdoffset;
 939                 sp->ttis[0].tt_isdst = 0;
 940                 sp->ttis[0].tt_abbrind = 0;
 941         }
 942         sp->charcnt = stdlen + 1;
 943         if (dstlen != 0)
 944                 sp->charcnt += dstlen + 1;
 945         if ((size_t) sp->charcnt > sizeof sp->chars)
 946                 return -1;
 947         cp = sp->chars;
 948         (void) strncpy(cp, stdname, stdlen);
 949         cp += stdlen;
 950         *cp++ = '\0';
 951         if (dstlen != 0) {
 952                 (void) strncpy(cp, dstname, dstlen);
 953                 *(cp + dstlen) = '\0';
 954         }
 955         return 0;
 956 }
 957
 958 static void
 959 gmtload(sp)
 960 struct state * const    sp;
 961 {
 962         if (tzload(gmt, sp) != 0)
 963                 (void) tzparse(gmt, sp, TRUE);
 964 }
 965
 966 static void
 967 tzsetwall_basic(int rdlocked)
 968 {
 969         if (!rdlocked)
 970                 _RWLOCK_RDLOCK(&lcl_rwlock);
 971         if (lcl_is_set < 0) {
 972                 if (!rdlocked)
 973                         _RWLOCK_UNLOCK(&lcl_rwlock);
 974                 return;
 975         }
 976         _RWLOCK_UNLOCK(&lcl_rwlock);
 977
 978         _RWLOCK_WRLOCK(&lcl_rwlock);
 979         lcl_is_set = -1;
 980
 981 #ifdef ALL_STATE
 982         if (lclptr == NULL) {
 983                 lclptr = (struct state *) malloc(sizeof *lclptr);
 984                 if (lclptr == NULL) {
 985                         settzname();    /* all we can do */
 986                         _RWLOCK_UNLOCK(&lcl_rwlock);
 987                         if (rdlocked)
 988                                 _RWLOCK_RDLOCK(&lcl_rwlock);
 989                         return;
 990                 }
 991         }
 992 #endif /* defined ALL_STATE */
 993         if (tzload((char *) NULL, lclptr) != 0)
 994                 gmtload(lclptr);
 995         settzname();
 996         _RWLOCK_UNLOCK(&lcl_rwlock);
 997
 998         if (rdlocked)
 999                 _RWLOCK_RDLOCK(&lcl_rwlock);
1000 }
1001
1002 void
1003 tzsetwall(void)
1004 {
1005         tzsetwall_basic(0);
1006 }
1007
1008 static void
1009 tzset_basic(int rdlocked)
1010 {
1011         const char *    name;
1012
1013         name = getenv("TZ");
1014         if (name == NULL) {
1015                 tzsetwall_basic(rdlocked);
1016                 return;
1017         }
1018
1019         if (!rdlocked)
1020                 _RWLOCK_RDLOCK(&lcl_rwlock);
1021         if (lcl_is_set > 0 && strcmp(lcl_TZname, name) == 0) {
1022                 if (!rdlocked)
1023                         _RWLOCK_UNLOCK(&lcl_rwlock);
1024                 return;
1025         }
1026         _RWLOCK_UNLOCK(&lcl_rwlock);
1027
1028         _RWLOCK_WRLOCK(&lcl_rwlock);
1029         lcl_is_set = strlen(name) < sizeof lcl_TZname;
1030         if (lcl_is_set)
1031                 (void) strcpy(lcl_TZname, name);
1032
1033 #ifdef ALL_STATE
1034         if (lclptr == NULL) {
1035                 lclptr = (struct state *) malloc(sizeof *lclptr);
1036                 if (lclptr == NULL) {
1037                         settzname();    /* all we can do */
1038                         _RWLOCK_UNLOCK(&lcl_rwlock);
1039                         if (rdlocked)
1040                                 _RWLOCK_RDLOCK(&lcl_rwlock);
1041                         return;
1042                 }
1043         }
1044 #endif /* defined ALL_STATE */
1045         if (*name == '\0') {
1046                 /*
1047                 ** User wants it fast rather than right.
1048                 */
1049                 lclptr->leapcnt = 0;            /* so, we're off a little */
1050                 lclptr->timecnt = 0;
1051                 lclptr->typecnt = 0;
1052                 lclptr->ttis[0].tt_isdst = 0;
1053                 lclptr->ttis[0].tt_gmtoff = 0;
1054                 lclptr->ttis[0].tt_abbrind = 0;
1055                 (void) strcpy(lclptr->chars, gmt);
1056         } else if (tzload(name, lclptr) != 0)
1057                 if (name[0] == ':' || tzparse(name, lclptr, FALSE) != 0)
1058                         (void) gmtload(lclptr);
1059         settzname();
1060         _RWLOCK_UNLOCK(&lcl_rwlock);
1061
1062         if (rdlocked)
1063                 _RWLOCK_RDLOCK(&lcl_rwlock);
1064 }
1065
1066 void
1067 tzset(void)
1068 {
1069         tzset_basic(0);
1070 }
1071
1072 /*
1073 ** The easy way to behave "as if no library function calls" localtime
1074 ** is to not call it--so we drop its guts into "localsub", which can be
1075 ** freely called.  (And no, the PANS doesn't require the above behavior--
1076 ** but it *is* desirable.)
1077 **
1078 ** The unused offset argument is for the benefit of mktime variants.
1079 */
1080
1081 /*ARGSUSED*/
1082 static void
1083 localsub(timep, offset, tmp)
1084 const time_t * const    timep;
1085 const long              offset;
1086 struct tm * const       tmp;
1087 {
1088         struct state *          sp;
1089         const struct ttinfo *   ttisp;
1090         int                     i;
1091         const time_t                    t = *timep;
1092
1093         sp = lclptr;
1094 #ifdef ALL_STATE
1095         if (sp == NULL) {
1096                 gmtsub(timep, offset, tmp);
1097                 return;
1098         }
1099 #endif /* defined ALL_STATE */
1100         if (sp->timecnt == 0 || t < sp->ats[0]) {
1101                 i = 0;
1102                 while (sp->ttis[i].tt_isdst)
1103                         if (++i >= sp->typecnt) {
1104                                 i = 0;
1105                                 break;
1106                         }
1107         } else {
1108                 for (i = 1; i < sp->timecnt; ++i)
1109                         if (t < sp->ats[i])
1110                                 break;
1111                 i = sp->types[i - 1];
1112         }
1113         ttisp = &sp->ttis[i];
1114         /*
1115         ** To get (wrong) behavior that's compatible with System V Release 2.0
1116         ** you'd replace the statement below with
1117         **      t += ttisp->tt_gmtoff;
1118         **      timesub(&t, 0L, sp, tmp);
1119         */
1120         timesub(&t, ttisp->tt_gmtoff, sp, tmp);
1121         tmp->tm_isdst = ttisp->tt_isdst;
1122         tzname[tmp->tm_isdst] = &sp->chars[ttisp->tt_abbrind];
1123 #ifdef TM_ZONE
1124         tmp->TM_ZONE = &sp->chars[ttisp->tt_abbrind];
1125 #endif /* defined TM_ZONE */
1126 }
1127
1128 struct tm *
1129 localtime(timep)
1130 const time_t * const    timep;
1131 {
1132         static pthread_mutex_t localtime_mutex = PTHREAD_MUTEX_INITIALIZER;
1133         static pthread_key_t localtime_key = -1;
1134         struct tm *p_tm;
1135
1136         if (__isthreaded != 0) {
1137                 _pthread_mutex_lock(&localtime_mutex);
1138                 if (localtime_key < 0) {
1139                         if (_pthread_key_create(&localtime_key, free) < 0) {
1140                                 _pthread_mutex_unlock(&localtime_mutex);
1141                                 return(NULL);
1142                         }
1143                 }
1144                 _pthread_mutex_unlock(&localtime_mutex);
1145                 p_tm = _pthread_getspecific(localtime_key);
1146                 if (p_tm == NULL) {
1147                         if ((p_tm = (struct tm *)malloc(sizeof(struct tm)))
1148                             == NULL)
1149                                 return(NULL);
1150                         _pthread_setspecific(localtime_key, p_tm);
1151                 }
1152                 _RWLOCK_RDLOCK(&lcl_rwlock);
1153                 tzset_basic(1);
1154                 localsub(timep, 0L, p_tm);
1155                 _RWLOCK_UNLOCK(&lcl_rwlock);
1156                 return(p_tm);
1157         } else {
1158                 tzset_basic(0);
1159                 localsub(timep, 0L, &tm);
1160                 return(&tm);
1161         }
1162 }
1163
1164 /*
1165 ** Re-entrant version of localtime.
1166 */
1167
1168 struct tm *
1169 localtime_r(timep, tm)
1170 const time_t * const    timep;
1171 struct tm *             tm;
1172 {
1173         _RWLOCK_RDLOCK(&lcl_rwlock);
1174         tzset_basic(1);
1175         localsub(timep, 0L, tm);
1176         _RWLOCK_UNLOCK(&lcl_rwlock);
1177         return tm;
1178 }
1179
1180 /*
1181 ** gmtsub is to gmtime as localsub is to localtime.
1182 */
1183
1184 static void
1185 gmtsub(timep, offset, tmp)
1186 const time_t * const    timep;
1187 const long              offset;
1188 struct tm * const       tmp;
1189 {
1190         _MUTEX_LOCK(&gmt_mutex);
1191         if (!gmt_is_set) {
1192                 gmt_is_set = TRUE;
1193 #ifdef ALL_STATE
1194                 gmtptr = (struct state *) malloc(sizeof *gmtptr);
1195                 if (gmtptr != NULL)
1196 #endif /* defined ALL_STATE */
1197                         gmtload(gmtptr);
1198         }
1199         _MUTEX_UNLOCK(&gmt_mutex);
1200         timesub(timep, offset, gmtptr, tmp);
1201 #ifdef TM_ZONE
1202         /*
1203         ** Could get fancy here and deliver something such as
1204         ** "UTC+xxxx" or "UTC-xxxx" if offset is non-zero,
1205         ** but this is no time for a treasure hunt.
1206         */
1207         if (offset != 0)
1208                 tmp->TM_ZONE = wildabbr;
1209         else {
1210 #ifdef ALL_STATE
1211                 if (gmtptr == NULL)
1212                         tmp->TM_ZONE = gmt;
1213                 else    tmp->TM_ZONE = gmtptr->chars;
1214 #endif /* defined ALL_STATE */
1215 #ifndef ALL_STATE
1216                 tmp->TM_ZONE = gmtptr->chars;
1217 #endif /* State Farm */
1218         }
1219 #endif /* defined TM_ZONE */
1220 }
1221
1222 struct tm *
1223 gmtime(timep)
1224 const time_t * const    timep;
1225 {
1226         static pthread_mutex_t gmtime_mutex = PTHREAD_MUTEX_INITIALIZER;
1227         static pthread_key_t gmtime_key = -1;
1228         struct tm *p_tm;
1229
1230         if (__isthreaded != 0) {
1231                 _pthread_mutex_lock(&gmtime_mutex);
1232                 if (gmtime_key < 0) {
1233                         if (_pthread_key_create(&gmtime_key, free) < 0) {
1234                                 _pthread_mutex_unlock(&gmtime_mutex);
1235                                 return(NULL);
1236                         }
1237                 }
1238                 _pthread_mutex_unlock(&gmtime_mutex);
1239                 /*
1240                  * Changed to follow POSIX.1 threads standard, which
1241                  * is what BSD currently has.
1242                  */
1243                 if ((p_tm = _pthread_getspecific(gmtime_key)) == NULL) {
1244                         if ((p_tm = (struct tm *)malloc(sizeof(struct tm)))
1245                             == NULL) {
1246                                 return(NULL);
1247                         }
1248                         _pthread_setspecific(gmtime_key, p_tm);
1249                 }
1250                 gmtsub(timep, 0L, p_tm);
1251                 return(p_tm);
1252         }
1253         else {
1254                 gmtsub(timep, 0L, &tm);
1255                 return(&tm);
1256         }
1257 }
1258
1259 /*
1260 * Re-entrant version of gmtime.
1261 */
1262
1263 struct tm *
1264 gmtime_r(timep, tm)
1265 const time_t * const    timep;
1266 struct tm *             tm;
1267 {
1268         gmtsub(timep, 0L, tm);
1269         return tm;
1270 }
1271
1272 #ifdef STD_INSPIRED
1273
1274 struct tm *
1275 offtime(timep, offset)
1276 const time_t * const    timep;
1277 const long              offset;
1278 {
1279         gmtsub(timep, offset, &tm);
1280         return &tm;
1281 }
1282
1283 #endif /* defined STD_INSPIRED */
1284
1285 static void
1286 timesub(timep, offset, sp, tmp)
1287 const time_t * const                    timep;
1288 const long                              offset;
1289 const struct state * const      sp;
1290 struct tm * const               tmp;
1291 {
1292         const struct lsinfo *   lp;
1293         long                    days;
1294         long                    rem;
1295         long                    y;
1296         int                     yleap;
1297         const int *             ip;
1298         long                    corr;
1299         int                     hit;
1300         int                     i;
1301
1302         corr = 0;
1303         hit = 0;
1304 #ifdef ALL_STATE
1305         i = (sp == NULL) ? 0 : sp->leapcnt;
1306 #endif /* defined ALL_STATE */
1307 #ifndef ALL_STATE
1308         i = sp->leapcnt;
1309 #endif /* State Farm */
1310         while (--i >= 0) {
1311                 lp = &sp->lsis[i];
1312                 if (*timep >= lp->ls_trans) {
1313                         if (*timep == lp->ls_trans) {
1314                                 hit = ((i == 0 && lp->ls_corr > 0) ||
1315                                         lp->ls_corr > sp->lsis[i - 1].ls_corr);
1316                                 if (hit)
1317                                         while (i > 0 &&
1318                                                 sp->lsis[i].ls_trans ==
1319                                                 sp->lsis[i - 1].ls_trans + 1 &&
1320                                                 sp->lsis[i].ls_corr ==
1321                                                 sp->lsis[i - 1].ls_corr + 1) {
1322                                                         ++hit;
1323                                                         --i;
1324                                         }
1325                         }
1326                         corr = lp->ls_corr;
1327                         break;
1328                 }
1329         }
1330         days = *timep / SECSPERDAY;
1331         rem = *timep % SECSPERDAY;
1332 #ifdef mc68k
1333         if (*timep == 0x80000000) {
1334                 /*
1335                 ** A 3B1 muffs the division on the most negative number.
1336                 */
1337                 days = -24855;
1338                 rem = -11648;
1339         }
1340 #endif /* defined mc68k */
1341         rem += (offset - corr);
1342         while (rem < 0) {
1343                 rem += SECSPERDAY;
1344                 --days;
1345         }
1346         while (rem >= SECSPERDAY) {
1347                 rem -= SECSPERDAY;
1348                 ++days;
1349         }
1350         tmp->tm_hour = (int) (rem / SECSPERHOUR);
1351         rem = rem % SECSPERHOUR;
1352         tmp->tm_min = (int) (rem / SECSPERMIN);
1353         /*
1354         ** A positive leap second requires a special
1355         ** representation.  This uses "... ??:59:60" et seq.
1356         */
1357         tmp->tm_sec = (int) (rem % SECSPERMIN) + hit;
1358         tmp->tm_wday = (int) ((EPOCH_WDAY + days) % DAYSPERWEEK);
1359         if (tmp->tm_wday < 0)
1360                 tmp->tm_wday += DAYSPERWEEK;
1361         y = EPOCH_YEAR;
1362 #define LEAPS_THRU_END_OF(y)    ((y) / 4 - (y) / 100 + (y) / 400)
1363         while (days < 0 || days >= (long) year_lengths[yleap = isleap(y)]) {
1364                 long    newy;
1365
1366                 newy = y + days / DAYSPERNYEAR;
1367                 if (days < 0)
1368                         --newy;
1369                 days -= (newy - y) * DAYSPERNYEAR +
1370                         LEAPS_THRU_END_OF(newy - 1) -
1371                         LEAPS_THRU_END_OF(y - 1);
1372                 y = newy;
1373         }
1374         tmp->tm_year = y - TM_YEAR_BASE;
1375         tmp->tm_yday = (int) days;
1376         ip = mon_lengths[yleap];
1377         for (tmp->tm_mon = 0; days >= (long) ip[tmp->tm_mon]; ++(tmp->tm_mon))
1378                 days = days - (long) ip[tmp->tm_mon];
1379         tmp->tm_mday = (int) (days + 1);
1380         tmp->tm_isdst = 0;
1381 #ifdef TM_GMTOFF
1382         tmp->TM_GMTOFF = offset;
1383 #endif /* defined TM_GMTOFF */
1384 }
1385
1386 char *
1387 ctime(timep)
1388 const time_t * const    timep;
1389 {
1390 /*
1391 ** Section 4.12.3.2 of X3.159-1989 requires that
1392 **      The ctime function converts the calendar time pointed to by timer
1393 **      to local time in the form of a string.  It is equivalent to
1394 **              asctime(localtime(timer))
1395 */
1396         return asctime(localtime(timep));
1397 }
1398
1399 char *
1400 ctime_r(timep, buf)
1401 const time_t * const    timep;
1402 char *                  buf;
1403 {
1404         struct tm       tm;
1405
1406         return asctime_r(localtime_r(timep, &tm), buf);
1407 }
1408
1409 /*
1410 ** Adapted from code provided by Robert Elz, who writes:
1411 **      The "best" way to do mktime I think is based on an idea of Bob
1412 **      Kridle's (so its said...) from a long time ago.
1413 **      [kridle@xinet.com as of 1996-01-16.]
1414 **      It does a binary search of the time_t space.  Since time_t's are
1415 **      just 32 bits, its a max of 32 iterations (even at 64 bits it
1416 **      would still be very reasonable).
1417 */
1418
1419 #ifndef WRONG
1420 #define WRONG   (-1)
1421 #endif /* !defined WRONG */
1422
1423 /*
1424 ** Simplified normalize logic courtesy Paul Eggert (eggert@twinsun.com).
1425 */
1426
1427 static int
1428 increment_overflow(number, delta)
1429 int *   number;
1430 int     delta;
1431 {
1432         int     number0;
1433
1434         number0 = *number;
1435         *number += delta;
1436         return (*number < number0) != (delta < 0);
1437 }
1438
1439 static int
1440 normalize_overflow(tensptr, unitsptr, base)
1441 int * const     tensptr;
1442 int * const     unitsptr;
1443 const int       base;
1444 {
1445         int     tensdelta;
1446
1447         tensdelta = (*unitsptr >= 0) ?
1448                 (*unitsptr / base) :
1449                 (-1 - (-1 - *unitsptr) / base);
1450         *unitsptr -= tensdelta * base;
1451         return increment_overflow(tensptr, tensdelta);
1452 }
1453
1454 static int
1455 tmcomp(atmp, btmp)
1456 const struct tm * const atmp;
1457 const struct tm * const btmp;
1458 {
1459         int     result;
1460
1461         if ((result = (atmp->tm_year - btmp->tm_year)) == 0 &&
1462                 (result = (atmp->tm_mon - btmp->tm_mon)) == 0 &&
1463                 (result = (atmp->tm_mday - btmp->tm_mday)) == 0 &&
1464                 (result = (atmp->tm_hour - btmp->tm_hour)) == 0 &&
1465                 (result = (atmp->tm_min - btmp->tm_min)) == 0)
1466                         result = atmp->tm_sec - btmp->tm_sec;
1467         return result;
1468 }
1469
1470 static time_t
1471 time2sub(tmp, funcp, offset, okayp, do_norm_secs)
1472 struct tm * const       tmp;
1473 void (* const           funcp)(const time_t*, long, struct tm*);
1474 const long              offset;
1475 int * const             okayp;
1476 const int               do_norm_secs;
1477 {
1478         const struct state *    sp;
1479         int                     dir;
1480         int                     bits;
1481         int                     i, j ;
1482         int                     saved_seconds;
1483         time_t                          newt;
1484         time_t                          t;
1485         struct tm                       yourtm, mytm;
1486
1487         *okayp = FALSE;
1488         yourtm = *tmp;
1489         if (do_norm_secs) {
1490                 if (normalize_overflow(&yourtm.tm_min, &yourtm.tm_sec,
1491                         SECSPERMIN))
1492                                 return WRONG;
1493         }
1494         if (normalize_overflow(&yourtm.tm_hour, &yourtm.tm_min, MINSPERHOUR))
1495                 return WRONG;
1496         if (normalize_overflow(&yourtm.tm_mday, &yourtm.tm_hour, HOURSPERDAY))
1497                 return WRONG;
1498         if (normalize_overflow(&yourtm.tm_year, &yourtm.tm_mon, MONSPERYEAR))
1499                 return WRONG;
1500         /*
1501         ** Turn yourtm.tm_year into an actual year number for now.
1502         ** It is converted back to an offset from TM_YEAR_BASE later.
1503         */
1504         if (increment_overflow(&yourtm.tm_year, TM_YEAR_BASE))
1505                 return WRONG;
1506         while (yourtm.tm_mday <= 0) {
1507                 if (increment_overflow(&yourtm.tm_year, -1))
1508                         return WRONG;
1509                 i = yourtm.tm_year + (1 < yourtm.tm_mon);
1510                 yourtm.tm_mday += year_lengths[isleap(i)];
1511         }
1512         while (yourtm.tm_mday > DAYSPERLYEAR) {
1513                 i = yourtm.tm_year + (1 < yourtm.tm_mon);
1514                 yourtm.tm_mday -= year_lengths[isleap(i)];
1515                 if (increment_overflow(&yourtm.tm_year, 1))
1516                         return WRONG;
1517         }
1518         for ( ; ; ) {
1519                 i = mon_lengths[isleap(yourtm.tm_year)][yourtm.tm_mon];
1520                 if (yourtm.tm_mday <= i)
1521                         break;
1522                 yourtm.tm_mday -= i;
1523                 if (++yourtm.tm_mon >= MONSPERYEAR) {
1524                         yourtm.tm_mon = 0;
1525                         if (increment_overflow(&yourtm.tm_year, 1))
1526                                 return WRONG;
1527                 }
1528         }
1529         if (increment_overflow(&yourtm.tm_year, -TM_YEAR_BASE))
1530                 return WRONG;
1531         /* Don't go below 1900 for POLA */
1532         if (yourtm.tm_year < 0)
1533                 return WRONG;
1534         if (yourtm.tm_sec >= 0 && yourtm.tm_sec < SECSPERMIN)
1535                 saved_seconds = 0;
1536         else if (yourtm.tm_year + TM_YEAR_BASE < EPOCH_YEAR) {
1537                 /*
1538                 ** We can't set tm_sec to 0, because that might push the
1539                 ** time below the minimum representable time.
1540                 ** Set tm_sec to 59 instead.
1541                 ** This assumes that the minimum representable time is
1542                 ** not in the same minute that a leap second was deleted from,
1543                 ** which is a safer assumption than using 58 would be.
1544                 */
1545                 if (increment_overflow(&yourtm.tm_sec, 1 - SECSPERMIN))
1546                         return WRONG;
1547                 saved_seconds = yourtm.tm_sec;
1548                 yourtm.tm_sec = SECSPERMIN - 1;
1549         } else {
1550                 saved_seconds = yourtm.tm_sec;
1551                 yourtm.tm_sec = 0;
1552         }
1553         /*
1554         ** Divide the search space in half
1555         ** (this works whether time_t is signed or unsigned).
1556         */
1557         bits = TYPE_BIT(time_t) - 1;
1558         /*
1559         ** If we have more than this, we will overflow tm_year for tmcomp().
1560         ** We should really return an error if we cannot represent it.
1561         */
1562         if (bits > 48)
1563                 bits = 48;
1564         /*
1565         ** If time_t is signed, then 0 is just above the median,
1566         ** assuming two's complement arithmetic.
1567         ** If time_t is unsigned, then (1 << bits) is just above the median.
1568         */
1569         t = TYPE_SIGNED(time_t) ? 0 : (((time_t) 1) << bits);
1570         for ( ; ; ) {
1571                 (*funcp)(&t, offset, &mytm);
1572                 dir = tmcomp(&mytm, &yourtm);
1573                 if (dir != 0) {
1574                         if (bits-- < 0)
1575                                 return WRONG;
1576                         if (bits < 0)
1577                                 --t; /* may be needed if new t is minimal */
1578                         else if (dir > 0)
1579                                 t -= ((time_t) 1) << bits;
1580                         else    t += ((time_t) 1) << bits;
1581                         continue;
1582                 }
1583                 if (yourtm.tm_isdst < 0 || mytm.tm_isdst == yourtm.tm_isdst)
1584                         break;
1585                 /*
1586                 ** Right time, wrong type.
1587                 ** Hunt for right time, right type.
1588                 ** It's okay to guess wrong since the guess
1589                 ** gets checked.
1590                 */
1591                 sp = (funcp == localsub) ? lclptr : gmtptr;
1592 #ifdef ALL_STATE
1593                 if (sp == NULL)
1594                         return WRONG;
1595 #endif /* defined ALL_STATE */
1596                 for (i = sp->typecnt - 1; i >= 0; --i) {
1597                         if (sp->ttis[i].tt_isdst != yourtm.tm_isdst)
1598                                 continue;
1599                         for (j = sp->typecnt - 1; j >= 0; --j) {
1600                                 if (sp->ttis[j].tt_isdst == yourtm.tm_isdst)
1601                                         continue;
1602                                 newt = t + sp->ttis[j].tt_gmtoff -
1603                                         sp->ttis[i].tt_gmtoff;
1604                                 (*funcp)(&newt, offset, &mytm);
1605                                 if (tmcomp(&mytm, &yourtm) != 0)
1606                                         continue;
1607                                 if (mytm.tm_isdst != yourtm.tm_isdst)
1608                                         continue;
1609                                 /*
1610                                 ** We have a match.
1611                                 */
1612                                 t = newt;
1613                                 goto label;
1614                         }
1615                 }
1616                 return WRONG;
1617         }
1618 label:
1619         newt = t + saved_seconds;
1620         if ((newt < t) != (saved_seconds < 0))
1621                 return WRONG;
1622         t = newt;
1623         (*funcp)(&t, offset, tmp);
1624         *okayp = TRUE;
1625         return t;
1626 }
1627
1628 static time_t
1629 time2(tmp, funcp, offset, okayp)
1630 struct tm * const       tmp;
1631 void (* const           funcp)(const time_t*, long, struct tm*);
1632 const long              offset;
1633 int * const             okayp;
1634 {
1635         time_t  t;
1636
1637         /*
1638         ** First try without normalization of seconds
1639         ** (in case tm_sec contains a value associated with a leap second).
1640         ** If that fails, try with normalization of seconds.
1641         */
1642         t = time2sub(tmp, funcp, offset, okayp, FALSE);
1643         return *okayp ? t : time2sub(tmp, funcp, offset, okayp, TRUE);
1644 }
1645
1646 static time_t
1647 time1(tmp, funcp, offset)
1648 struct tm * const       tmp;
1649 void (* const           funcp)(const time_t *, long, struct tm *);
1650 const long              offset;
1651 {
1652         time_t                  t;
1653         const struct state *    sp;
1654         int                     samei, otheri;
1655         int                     sameind, otherind;
1656         int                     i;
1657         int                     nseen;
1658         int                             seen[TZ_MAX_TYPES];
1659         int                             types[TZ_MAX_TYPES];
1660         int                             okay;
1661
1662         if (tmp->tm_isdst > 1)
1663                 tmp->tm_isdst = 1;
1664         t = time2(tmp, funcp, offset, &okay);
1665 #ifdef PCTS
1666         /*
1667         ** PCTS code courtesy Grant Sullivan (grant@osf.org).
1668         */
1669         if (okay)
1670                 return t;
1671         if (tmp->tm_isdst < 0)
1672                 tmp->tm_isdst = 0;      /* reset to std and try again */
1673 #endif /* defined PCTS */
1674 #ifndef PCTS
1675         if (okay || tmp->tm_isdst < 0)
1676                 return t;
1677 #endif /* !defined PCTS */
1678         /*
1679         ** We're supposed to assume that somebody took a time of one type
1680         ** and did some math on it that yielded a "struct tm" that's bad.
1681         ** We try to divine the type they started from and adjust to the
1682         ** type they need.
1683         */
1684         sp = (funcp == localsub) ? lclptr : gmtptr;
1685 #ifdef ALL_STATE
1686         if (sp == NULL)
1687                 return WRONG;
1688 #endif /* defined ALL_STATE */
1689         for (i = 0; i < sp->typecnt; ++i)
1690                 seen[i] = FALSE;
1691         nseen = 0;
1692         for (i = sp->timecnt - 1; i >= 0; --i)
1693                 if (!seen[sp->types[i]]) {
1694                         seen[sp->types[i]] = TRUE;
1695                         types[nseen++] = sp->types[i];
1696                 }
1697         for (sameind = 0; sameind < nseen; ++sameind) {
1698                 samei = types[sameind];
1699                 if (sp->ttis[samei].tt_isdst != tmp->tm_isdst)
1700                         continue;
1701                 for (otherind = 0; otherind < nseen; ++otherind) {
1702                         otheri = types[otherind];
1703                         if (sp->ttis[otheri].tt_isdst == tmp->tm_isdst)
1704                                 continue;
1705                         tmp->tm_sec += sp->ttis[otheri].tt_gmtoff -
1706                                         sp->ttis[samei].tt_gmtoff;
1707                         tmp->tm_isdst = !tmp->tm_isdst;
1708                         t = time2(tmp, funcp, offset, &okay);
1709                         if (okay)
1710                                 return t;
1711                         tmp->tm_sec -= sp->ttis[otheri].tt_gmtoff -
1712                                         sp->ttis[samei].tt_gmtoff;
1713                         tmp->tm_isdst = !tmp->tm_isdst;
1714                 }
1715         }
1716         return WRONG;
1717 }
1718
1719 time_t
1720 mktime(tmp)
1721 struct tm * const       tmp;
1722 {
1723         time_t mktime_return_value;
1724         _RWLOCK_RDLOCK(&lcl_rwlock);
1725         tzset_basic(1);
1726         mktime_return_value = time1(tmp, localsub, 0L);
1727         _RWLOCK_UNLOCK(&lcl_rwlock);
1728         return(mktime_return_value);
1729 }
1730
1731 #ifdef STD_INSPIRED
1732
1733 time_t
1734 timelocal(tmp)
1735 struct tm * const       tmp;
1736 {
1737         tmp->tm_isdst = -1;     /* in case it wasn't initialized */
1738         return mktime(tmp);
1739 }
1740
1741 time_t
1742 timegm(tmp)
1743 struct tm * const       tmp;
1744 {
1745         tmp->tm_isdst = 0;
1746         return time1(tmp, gmtsub, 0L);
1747 }
1748
1749 time_t
1750 timeoff(tmp, offset)
1751 struct tm * const       tmp;
1752 const long              offset;
1753 {
1754         tmp->tm_isdst = 0;
1755         return time1(tmp, gmtsub, offset);
1756 }
1757
1758 #endif /* defined STD_INSPIRED */
1759
1760 #ifdef CMUCS
1761
1762 /*
1763 ** The following is supplied for compatibility with
1764 ** previous versions of the CMUCS runtime library.
1765 */
1766
1767 long
1768 gtime(tmp)
1769 struct tm * const       tmp;
1770 {
1771         const time_t    t = mktime(tmp);
1772
1773         if (t == WRONG)
1774                 return -1;
1775         return t;
1776 }
1777
1778 #endif /* defined CMUCS */
1779
1780 /*
1781 ** XXX--is the below the right way to conditionalize??
1782 */
1783
1784 #ifdef STD_INSPIRED
1785
1786 /*
1787 ** IEEE Std 1003.1-1988 (POSIX) legislates that 536457599
1788 ** shall correspond to "Wed Dec 31 23:59:59 UTC 1986", which
1789 ** is not the case if we are accounting for leap seconds.
1790 ** So, we provide the following conversion routines for use
1791 ** when exchanging timestamps with POSIX conforming systems.
1792 */
1793
1794 static long
1795 leapcorr(timep)
1796 time_t *        timep;
1797 {
1798         struct state *          sp;
1799         struct lsinfo * lp;
1800         int                     i;
1801
1802         sp = lclptr;
1803         i = sp->leapcnt;
1804         while (--i >= 0) {
1805                 lp = &sp->lsis[i];
1806                 if (*timep >= lp->ls_trans)
1807                         return lp->ls_corr;
1808         }
1809         return 0;
1810 }
1811
1812 time_t
1813 time2posix(t)
1814 time_t  t;
1815 {
1816         tzset();
1817         return t - leapcorr(&t);
1818 }
1819
1820 time_t
1821 posix2time(t)
1822 time_t  t;
1823 {
1824         time_t  x;
1825         time_t  y;
1826
1827         tzset();
1828         /*
1829         ** For a positive leap second hit, the result
1830         ** is not unique.  For a negative leap second
1831         ** hit, the corresponding time doesn't exist,
1832         ** so we return an adjacent second.
1833         */
1834         x = t + leapcorr(&t);
1835         y = x - leapcorr(&x);
1836         if (y < t) {
1837                 do {
1838                         x++;
1839                         y = x - leapcorr(&x);
1840                 } while (y < t);
1841                 if (t != y)
1842                         return x - 1;
1843         } else if (y > t) {
1844                 do {
1845                         --x;
1846                         y = x - leapcorr(&x);
1847                 } while (y > t);
1848                 if (t != y)
1849                         return x + 1;
1850         }
1851         return x;
1852 }
1853
1854 #endif /* defined STD_INSPIRED */