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 /*
  38 ** SunOS 4.1.1 headers lack O_BINARY.
  39 */
  40
  41 #ifdef O_BINARY
  42 #define OPEN_MODE       (O_RDONLY | O_BINARY)
  43 #endif /* defined O_BINARY */
  44 #ifndef O_BINARY
  45 #define OPEN_MODE       O_RDONLY
  46 #endif /* !defined O_BINARY */
  47
  48 #ifndef WILDABBR
  49 /*
  50 ** Someone might make incorrect use of a time zone abbreviation:
  51 **      1.      They might reference tzname[0] before calling tzset (explicitly
  52 **              or implicitly).
  53 **      2.      They might reference tzname[1] before calling tzset (explicitly
  54 **              or implicitly).
  55 **      3.      They might reference tzname[1] after setting to a time zone
  56 **              in which Daylight Saving Time is never observed.
  57 **      4.      They might reference tzname[0] after setting to a time zone
  58 **              in which Standard Time is never observed.
  59 **      5.      They might reference tm.TM_ZONE after calling offtime.
  60 ** What's best to do in the above cases is open to debate;
  61 ** for now, we just set things up so that in any of the five cases
  62 ** WILDABBR is used.  Another possibility:  initialize tzname[0] to the
  63 ** string "tzname[0] used before set", and similarly for the other cases.
  64 ** And another:  initialize tzname[0] to "ERA", with an explanation in the
  65 ** manual page of what this "time zone abbreviation" means (doing this so
  66 ** that tzname[0] has the "normal" length of three characters).
  67 */
  68 #define WILDABBR        "   "
  69 #endif /* !defined WILDABBR */
  70
  71 static char             wildabbr[] = "WILDABBR";
  72
  73 /*
  74  * In June 2004 it was decided UTC was a more appropriate default time
  75  * zone than GMT.
  76  */
  77
  78 static const char       gmt[] = "UTC";
  79
  80 /*
  81 ** The DST rules to use if TZ has no rules and we can't load TZDEFRULES.
  82 ** We default to US rules as of 1999-08-17.
  83 ** POSIX 1003.1 section 8.1.1 says that the default DST rules are
  84 ** implementation dependent; for historical reasons, US rules are a
  85 ** common default.
  86 */
  87 #ifndef TZDEFRULESTRING
  88 #define TZDEFRULESTRING ",M4.1.0,M10.5.0"
  89 #endif /* !defined TZDEFDST */
  90
  91 struct ttinfo {                         /* time type information */
  92         long            tt_gmtoff;      /* UTC offset in seconds */
  93         int             tt_isdst;       /* used to set tm_isdst */
  94         int             tt_abbrind;     /* abbreviation list index */
  95         int             tt_ttisstd;     /* TRUE if transition is std time */
  96         int             tt_ttisgmt;     /* TRUE if transition is UTC */
  97 };
  98
  99 struct lsinfo {                         /* leap second information */
 100         time_t          ls_trans;       /* transition time */
 101         long            ls_corr;        /* correction to apply */
 102 };
 103
 104 #define BIGGEST(a, b)   (((a) > (b)) ? (a) : (b))
 105
 106 #ifdef TZNAME_MAX
 107 #define MY_TZNAME_MAX   TZNAME_MAX
 108 #endif /* defined TZNAME_MAX */
 109 #ifndef TZNAME_MAX
 110 #define MY_TZNAME_MAX   255
 111 #endif /* !defined TZNAME_MAX */
 112
 113 struct state {
 114         int             leapcnt;
 115         int             timecnt;
 116         int             typecnt;
 117         int             charcnt;
 118         time_t          ats[TZ_MAX_TIMES];
 119         unsigned char   types[TZ_MAX_TIMES];
 120         struct ttinfo   ttis[TZ_MAX_TYPES];
 121         char            chars[BIGGEST(BIGGEST(TZ_MAX_CHARS + 1, sizeof gmt),
 122                                 (2 * (MY_TZNAME_MAX + 1)))];
 123         struct lsinfo   lsis[TZ_MAX_LEAPS];
 124 };
 125
 126 struct rule {
 127         int             r_type;         /* type of rule--see below */
 128         int             r_day;          /* day number of rule */
 129         int             r_week;         /* week number of rule */
 130         int             r_mon;          /* month number of rule */
 131         long            r_time;         /* transition time of rule */
 132 };
 133
 134 #define JULIAN_DAY              0       /* Jn - Julian day */
 135 #define DAY_OF_YEAR             1       /* n - day of year */
 136 #define MONTH_NTH_DAY_OF_WEEK   2       /* Mm.n.d - month, week, day of week */
 137
 138 /*
 139 ** Prototypes for static functions.
 140 */
 141
 142 static long             detzcode(const char * codep);
 143 static const char *     getzname(const char * strp);
 144 static const char *     getnum(const char * strp, int * nump, int min,
 145                                 int max);
 146 static const char *     getsecs(const char * strp, long * secsp);
 147 static const char *     getoffset(const char * strp, long * offsetp);
 148 static const char *     getrule(const char * strp, struct rule * rulep);
 149 static void             gmtload(struct state * sp);
 150 static void             gmtsub(const time_t * timep, long offset,
 151                                 struct tm * tmp);
 152 static void             localsub(const time_t * timep, long offset,
 153                                 struct tm * tmp);
 154 static int              increment_overflow(int * number, int delta);
 155 static int              normalize_overflow(int * tensptr, int * unitsptr,
 156                                 int base);
 157 static void             settzname(void);
 158 static time_t           time1(struct tm * tmp,
 159                                 void(*funcp) (const time_t *,
 160                                 long, struct tm *),
 161                                 long offset);
 162 static time_t           time2(struct tm *tmp,
 163                                 void(*funcp) (const time_t *,
 164                                 long, struct tm*),
 165                                 long offset, int * okayp);
 166 static time_t           time2sub(struct tm *tmp,
 167                                 void(*funcp) (const time_t *,
 168                                 long, struct tm*),
 169                                 long offset, int * okayp, int do_norm_secs);
 170 static void             timesub(const time_t * timep, long offset,
 171                                 const struct state * sp, struct tm * tmp);
 172 static int              tmcomp(const struct tm * atmp,
 173                                 const struct tm * btmp);
 174 static time_t           transtime(time_t janfirst, int year,
 175                                 const struct rule * rulep, long offset);
 176 static int              tzload(const char * name, struct state * sp);
 177 static int              tzparse(const char * name, struct state * sp,
 178                                 int lastditch);
 179
 180 #ifdef ALL_STATE
 181 static struct state *   lclptr;
 182 static struct state *   gmtptr;
 183 #endif /* defined ALL_STATE */
 184
 185 #ifndef ALL_STATE
 186 static struct state     lclmem;
 187 static struct state     gmtmem;
 188 #define lclptr          (&lclmem)
 189 #define gmtptr          (&gmtmem)
 190 #endif /* State Farm */
 191
 192 #ifndef TZ_STRLEN_MAX
 193 #define TZ_STRLEN_MAX 255
 194 #endif /* !defined TZ_STRLEN_MAX */
 195
 196 static char             lcl_TZname[TZ_STRLEN_MAX + 1];
 197 static int              lcl_is_set;
 198 static int              gmt_is_set;
 199 static pthread_mutex_t  lcl_mutex = PTHREAD_MUTEX_INITIALIZER;
 200 static pthread_mutex_t  gmt_mutex = PTHREAD_MUTEX_INITIALIZER;
 201
 202 char *                  tzname[2] = {
 203         wildabbr,
 204         wildabbr
 205 };
 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 (eggert@twinsun.com) for noting this.
 213 */
 214
 215 static struct tm        tm;
 216
 217 #ifdef USG_COMPAT
 218 time_t                  timezone = 0;
 219 int                     daylight = 0;
 220 #endif /* defined USG_COMPAT */
 221
 222 #ifdef ALTZONE
 223 time_t                  altzone = 0;
 224 #endif /* defined ALTZONE */
 225
 226 static long
 227 detzcode(codep)
 228 const char * const      codep;
 229 {
 230         long    result;
 231         int     i;
 232
 233         result = (codep[0] & 0x80) ? ~0L : 0L;
 234         for (i = 0; i < 4; ++i)
 235                 result = (result << 8) | (codep[i] & 0xff);
 236         return result;
 237 }
 238
 239 static void
 240 settzname(void)
 241 {
 242         struct state *  sp = lclptr;
 243         int                     i;
 244
 245         tzname[0] = wildabbr;
 246         tzname[1] = wildabbr;
 247 #ifdef USG_COMPAT
 248         daylight = 0;
 249         timezone = 0;
 250 #endif /* defined USG_COMPAT */
 251 #ifdef ALTZONE
 252         altzone = 0;
 253 #endif /* defined ALTZONE */
 254 #ifdef ALL_STATE
 255         if (sp == NULL) {
 256                 tzname[0] = tzname[1] = gmt;
 257                 return;
 258         }
 259 #endif /* defined ALL_STATE */
 260         for (i = 0; i < sp->typecnt; ++i) {
 261                 const struct ttinfo * const     ttisp = &sp->ttis[i];
 262
 263                 tzname[ttisp->tt_isdst] =
 264                         &sp->chars[ttisp->tt_abbrind];
 265 #ifdef USG_COMPAT
 266                 if (ttisp->tt_isdst)
 267                         daylight = 1;
 268                 if (i == 0 || !ttisp->tt_isdst)
 269                         timezone = -(ttisp->tt_gmtoff);
 270 #endif /* defined USG_COMPAT */
 271 #ifdef ALTZONE
 272                 if (i == 0 || ttisp->tt_isdst)
 273                         altzone = -(ttisp->tt_gmtoff);
 274 #endif /* defined ALTZONE */
 275         }
 276         /*
 277         ** And to get the latest zone names into tzname. . .
 278         */
 279         for (i = 0; i < sp->timecnt; ++i) {
 280                 const struct ttinfo * const     ttisp =
 281                                                         &sp->ttis[
 282                                                                 sp->types[i]];
 283
 284                 tzname[ttisp->tt_isdst] =
 285                         &sp->chars[ttisp->tt_abbrind];
 286         }
 287 }
 288
 289 static int
 290 tzload(name, sp)
 291 const char *            name;
 292 struct state * const    sp;
 293 {
 294         const char *    p;
 295         int             i;
 296         int             fid;
 297
 298         /* XXX The following is from OpenBSD, and I'm not sure it is correct */
 299         if (name != NULL && issetugid() != 0)
 300                 if ((name[0] == ':' && name[1] == '/') ||
 301                     name[0] == '/' || strchr(name, '.'))
 302                         name = NULL;
 303         if (name == NULL && (name = TZDEFAULT) == NULL)
 304                 return -1;
 305         {
 306                 int     doaccess;
 307                 struct stat     stab;
 308                 /*
 309                 ** Section 4.9.1 of the C standard says that
 310                 ** "FILENAME_MAX expands to an integral constant expression
 311                 ** that is the size needed for an array of char large enough
 312                 ** to hold the longest file name string that the implementation
 313                 ** guarantees can be opened."
 314                 */
 315                 char            fullname[FILENAME_MAX + 1];
 316
 317                 if (name[0] == ':')
 318                         ++name;
 319                 doaccess = name[0] == '/';
 320                 if (!doaccess) {
 321                         if ((p = TZDIR) == NULL)
 322                                 return -1;
 323                         if ((strlen(p) + 1 + strlen(name) + 1) >= sizeof fullname)
 324                                 return -1;
 325                         (void) strcpy(fullname, p);
 326                         (void) strcat(fullname, "/");
 327                         (void) strcat(fullname, name);
 328                         /*
 329                         ** Set doaccess if '.' (as in "../") shows up in name.
 330                         */
 331                         if (strchr(name, '.') != NULL)
 332                                 doaccess = TRUE;
 333                         name = fullname;
 334                 }
 335                 if (doaccess && access(name, R_OK) != 0)
 336                         return -1;
 337                 if ((fid = _open(name, OPEN_MODE)) == -1)
 338                         return -1;
 339                 if ((_fstat(fid, &stab) < 0) || !S_ISREG(stab.st_mode)) {
 340                         _close(fid);
 341                         return -1;
 342                 }
 343         }
 344         {
 345                 struct tzhead * tzhp;
 346                 union {
 347                         struct tzhead   tzhead;
 348                         char            buf[sizeof *sp + sizeof *tzhp];
 349                 } u;
 350                 int             ttisstdcnt;
 351                 int             ttisgmtcnt;
 352
 353                 i = _read(fid, u.buf, sizeof u.buf);
 354                 if (_close(fid) != 0)
 355                         return -1;
 356                 ttisstdcnt = (int) detzcode(u.tzhead.tzh_ttisstdcnt);
 357                 ttisgmtcnt = (int) detzcode(u.tzhead.tzh_ttisgmtcnt);
 358                 sp->leapcnt = (int) detzcode(u.tzhead.tzh_leapcnt);
 359                 sp->timecnt = (int) detzcode(u.tzhead.tzh_timecnt);
 360                 sp->typecnt = (int) detzcode(u.tzhead.tzh_typecnt);
 361                 sp->charcnt = (int) detzcode(u.tzhead.tzh_charcnt);
 362                 p = u.tzhead.tzh_charcnt + sizeof u.tzhead.tzh_charcnt;
 363                 if (sp->leapcnt < 0 || sp->leapcnt > TZ_MAX_LEAPS ||
 364                         sp->typecnt <= 0 || sp->typecnt > TZ_MAX_TYPES ||
 365                         sp->timecnt < 0 || sp->timecnt > TZ_MAX_TIMES ||
 366                         sp->charcnt < 0 || sp->charcnt > TZ_MAX_CHARS ||
 367                         (ttisstdcnt != sp->typecnt && ttisstdcnt != 0) ||
 368                         (ttisgmtcnt != sp->typecnt && ttisgmtcnt != 0))
 369                                 return -1;
 370                 if (i - (p - u.buf) < sp->timecnt * 4 + /* ats */
 371                         sp->timecnt +                   /* types */
 372                         sp->typecnt * (4 + 2) +         /* ttinfos */
 373                         sp->charcnt +                   /* chars */
 374                         sp->leapcnt * (4 + 4) +         /* lsinfos */
 375                         ttisstdcnt +                    /* ttisstds */
 376                         ttisgmtcnt)                     /* ttisgmts */
 377                                 return -1;
 378                 for (i = 0; i < sp->timecnt; ++i) {
 379                         sp->ats[i] = detzcode(p);
 380                         p += 4;
 381                 }
 382                 for (i = 0; i < sp->timecnt; ++i) {
 383                         sp->types[i] = (unsigned char) *p++;
 384                         if (sp->types[i] >= sp->typecnt)
 385                                 return -1;
 386                 }
 387                 for (i = 0; i < sp->typecnt; ++i) {
 388                         struct ttinfo * ttisp;
 389
 390                         ttisp = &sp->ttis[i];
 391                         ttisp->tt_gmtoff = detzcode(p);
 392                         p += 4;
 393                         ttisp->tt_isdst = (unsigned char) *p++;
 394                         if (ttisp->tt_isdst != 0 && ttisp->tt_isdst != 1)
 395                                 return -1;
 396                         ttisp->tt_abbrind = (unsigned char) *p++;
 397                         if (ttisp->tt_abbrind < 0 ||
 398                                 ttisp->tt_abbrind > sp->charcnt)
 399                                         return -1;
 400                 }
 401                 for (i = 0; i < sp->charcnt; ++i)
 402                         sp->chars[i] = *p++;
 403                 sp->chars[i] = '\0';    /* ensure '\0' at end */
 404                 for (i = 0; i < sp->leapcnt; ++i) {
 405                         struct lsinfo * lsisp;
 406
 407                         lsisp = &sp->lsis[i];
 408                         lsisp->ls_trans = detzcode(p);
 409                         p += 4;
 410                         lsisp->ls_corr = detzcode(p);
 411                         p += 4;
 412                 }
 413                 for (i = 0; i < sp->typecnt; ++i) {
 414                         struct ttinfo * ttisp;
 415
 416                         ttisp = &sp->ttis[i];
 417                         if (ttisstdcnt == 0)
 418                                 ttisp->tt_ttisstd = FALSE;
 419                         else {
 420                                 ttisp->tt_ttisstd = *p++;
 421                                 if (ttisp->tt_ttisstd != TRUE &&
 422                                         ttisp->tt_ttisstd != FALSE)
 423                                                 return -1;
 424                         }
 425                 }
 426                 for (i = 0; i < sp->typecnt; ++i) {
 427                         struct ttinfo * ttisp;
 428
 429                         ttisp = &sp->ttis[i];
 430                         if (ttisgmtcnt == 0)
 431                                 ttisp->tt_ttisgmt = FALSE;
 432                         else {
 433                                 ttisp->tt_ttisgmt = *p++;
 434                                 if (ttisp->tt_ttisgmt != TRUE &&
 435                                         ttisp->tt_ttisgmt != FALSE)
 436                                                 return -1;
 437                         }
 438                 }
 439         }
 440         return 0;
 441 }
 442
 443 static const int        mon_lengths[2][MONSPERYEAR] = {
 444         { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 },
 445         { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }
 446 };
 447
 448 static const int        year_lengths[2] = {
 449         DAYSPERNYEAR, DAYSPERLYEAR
 450 };
 451
 452 /*
 453 ** Given a pointer into a time zone string, scan until a character that is not
 454 ** a valid character in a zone name is found.  Return a pointer to that
 455 ** character.
 456 */
 457
 458 static const char *
 459 getzname(strp)
 460 const char *    strp;
 461 {
 462         char    c;
 463
 464         while ((c = *strp) != '\0' && !is_digit(c) && c != ',' && c != '-' &&
 465                 c != '+')
 466                         ++strp;
 467         return strp;
 468 }
 469
 470 /*
 471 ** Given a pointer into a time zone string, extract a number from that string.
 472 ** Check that the number is within a specified range; if it is not, return
 473 ** NULL.
 474 ** Otherwise, return a pointer to the first character not part of the number.
 475 */
 476
 477 static const char *
 478 getnum(strp, nump, min, max)
 479 const char *    strp;
 480 int * const             nump;
 481 const int               min;
 482 const int               max;
 483 {
 484         char    c;
 485         int     num;
 486
 487         if (strp == NULL || !is_digit(c = *strp))
 488                 return NULL;
 489         num = 0;
 490         do {
 491                 num = num * 10 + (c - '0');
 492                 if (num > max)
 493                         return NULL;    /* illegal value */
 494                 c = *++strp;
 495         } while (is_digit(c));
 496         if (num < min)
 497                 return NULL;            /* illegal value */
 498         *nump = num;
 499         return strp;
 500 }
 501
 502 /*
 503 ** Given a pointer into a time zone string, extract a number of seconds,
 504 ** in hh[:mm[:ss]] form, from the string.
 505 ** If any error occurs, return NULL.
 506 ** Otherwise, return a pointer to the first character not part of the number
 507 ** of seconds.
 508 */
 509
 510 static const char *
 511 getsecs(strp, secsp)
 512 const char *    strp;
 513 long * const            secsp;
 514 {
 515         int     num;
 516
 517         /*
 518         ** `HOURSPERDAY * DAYSPERWEEK - 1' allows quasi-Posix rules like
 519         ** "M10.4.6/26", which does not conform to Posix,
 520         ** but which specifies the equivalent of
 521         ** ``02:00 on the first Sunday on or after 23 Oct''.
 522         */
 523         strp = getnum(strp, &num, 0, HOURSPERDAY * DAYSPERWEEK - 1);
 524         if (strp == NULL)
 525                 return NULL;
 526         *secsp = num * (long) SECSPERHOUR;
 527         if (*strp == ':') {
 528                 ++strp;
 529                 strp = getnum(strp, &num, 0, MINSPERHOUR - 1);
 530                 if (strp == NULL)
 531                         return NULL;
 532                 *secsp += num * SECSPERMIN;
 533                 if (*strp == ':') {
 534                         ++strp;
 535                         /* `SECSPERMIN' allows for leap seconds.  */
 536                         strp = getnum(strp, &num, 0, SECSPERMIN);
 537                         if (strp == NULL)
 538                                 return NULL;
 539                         *secsp += num;
 540                 }
 541         }
 542         return strp;
 543 }
 544
 545 /*
 546 ** Given a pointer into a time zone string, extract an offset, in
 547 ** [+-]hh[:mm[:ss]] form, from the string.
 548 ** If any error occurs, return NULL.
 549 ** Otherwise, return a pointer to the first character not part of the time.
 550 */
 551
 552 static const char *
 553 getoffset(strp, offsetp)
 554 const char *    strp;
 555 long * const            offsetp;
 556 {
 557         int     neg = 0;
 558
 559         if (*strp == '-') {
 560                 neg = 1;
 561                 ++strp;
 562         } else if (*strp == '+')
 563                 ++strp;
 564         strp = getsecs(strp, offsetp);
 565         if (strp == NULL)
 566                 return NULL;            /* illegal time */
 567         if (neg)
 568                 *offsetp = -*offsetp;
 569         return strp;
 570 }
 571
 572 /*
 573 ** Given a pointer into a time zone string, extract a rule in the form
 574 ** date[/time].  See POSIX section 8 for the format of "date" and "time".
 575 ** If a valid rule is not found, return NULL.
 576 ** Otherwise, return a pointer to the first character not part of the rule.
 577 */
 578
 579 static const char *
 580 getrule(strp, rulep)
 581 const char *                    strp;
 582 struct rule * const     rulep;
 583 {
 584         if (*strp == 'J') {
 585                 /*
 586                 ** Julian day.
 587                 */
 588                 rulep->r_type = JULIAN_DAY;
 589                 ++strp;
 590                 strp = getnum(strp, &rulep->r_day, 1, DAYSPERNYEAR);
 591         } else if (*strp == 'M') {
 592                 /*
 593                 ** Month, week, day.
 594                 */
 595                 rulep->r_type = MONTH_NTH_DAY_OF_WEEK;
 596                 ++strp;
 597                 strp = getnum(strp, &rulep->r_mon, 1, MONSPERYEAR);
 598                 if (strp == NULL)
 599                         return NULL;
 600                 if (*strp++ != '.')
 601                         return NULL;
 602                 strp = getnum(strp, &rulep->r_week, 1, 5);
 603                 if (strp == NULL)
 604                         return NULL;
 605                 if (*strp++ != '.')
 606                         return NULL;
 607                 strp = getnum(strp, &rulep->r_day, 0, DAYSPERWEEK - 1);
 608         } else if (is_digit(*strp)) {
 609                 /*
 610                 ** Day of year.
 611                 */
 612                 rulep->r_type = DAY_OF_YEAR;
 613                 strp = getnum(strp, &rulep->r_day, 0, DAYSPERLYEAR - 1);
 614         } else  return NULL;            /* invalid format */
 615         if (strp == NULL)
 616                 return NULL;
 617         if (*strp == '/') {
 618                 /*
 619                 ** Time specified.
 620                 */
 621                 ++strp;
 622                 strp = getsecs(strp, &rulep->r_time);
 623         } else  rulep->r_time = 2 * SECSPERHOUR;        /* default = 2:00:00 */
 624         return strp;
 625 }
 626
 627 /*
 628 ** Given the Epoch-relative time of January 1, 00:00:00 UTC, in a year, the
 629 ** year, a rule, and the offset from UTC at the time that rule takes effect,
 630 ** calculate the Epoch-relative time that rule takes effect.
 631 */
 632
 633 static time_t
 634 transtime(janfirst, year, rulep, offset)
 635 const time_t                            janfirst;
 636 const int                               year;
 637 const struct rule * const       rulep;
 638 const long                              offset;
 639 {
 640         int     leapyear;
 641         time_t  value;
 642         int     i;
 643         int             d, m1, yy0, yy1, yy2, dow;
 644
 645         INITIALIZE(value);
 646         leapyear = isleap(year);
 647         switch (rulep->r_type) {
 648
 649         case JULIAN_DAY:
 650                 /*
 651                 ** Jn - Julian day, 1 == January 1, 60 == March 1 even in leap
 652                 ** years.
 653                 ** In non-leap years, or if the day number is 59 or less, just
 654                 ** add SECSPERDAY times the day number-1 to the time of
 655                 ** January 1, midnight, to get the day.
 656                 */
 657                 value = janfirst + (rulep->r_day - 1) * SECSPERDAY;
 658                 if (leapyear && rulep->r_day >= 60)
 659                         value += SECSPERDAY;
 660                 break;
 661
 662         case DAY_OF_YEAR:
 663                 /*
 664                 ** n - day of year.
 665                 ** Just add SECSPERDAY times the day number to the time of
 666                 ** January 1, midnight, to get the day.
 667                 */
 668                 value = janfirst + rulep->r_day * SECSPERDAY;
 669                 break;
 670
 671         case MONTH_NTH_DAY_OF_WEEK:
 672                 /*
 673                 ** Mm.n.d - nth "dth day" of month m.
 674                 */
 675                 value = janfirst;
 676                 for (i = 0; i < rulep->r_mon - 1; ++i)
 677                         value += mon_lengths[leapyear][i] * SECSPERDAY;
 678
 679                 /*
 680                 ** Use Zeller's Congruence to get day-of-week of first day of
 681                 ** month.
 682                 */
 683                 m1 = (rulep->r_mon + 9) % 12 + 1;
 684                 yy0 = (rulep->r_mon <= 2) ? (year - 1) : year;
 685                 yy1 = yy0 / 100;
 686                 yy2 = yy0 % 100;
 687                 dow = ((26 * m1 - 2) / 10 +
 688                         1 + yy2 + yy2 / 4 + yy1 / 4 - 2 * yy1) % 7;
 689                 if (dow < 0)
 690                         dow += DAYSPERWEEK;
 691
 692                 /*
 693                 ** "dow" is the day-of-week of the first day of the month.  Get
 694                 ** the day-of-month (zero-origin) of the first "dow" day of the
 695                 ** month.
 696                 */
 697                 d = rulep->r_day - dow;
 698                 if (d < 0)
 699                         d += DAYSPERWEEK;
 700                 for (i = 1; i < rulep->r_week; ++i) {
 701                         if (d + DAYSPERWEEK >=
 702                                 mon_lengths[leapyear][rulep->r_mon - 1])
 703                                         break;
 704                         d += DAYSPERWEEK;
 705                 }
 706
 707                 /*
 708                 ** "d" is the day-of-month (zero-origin) of the day we want.
 709                 */
 710                 value += d * SECSPERDAY;
 711                 break;
 712         }
 713
 714         /*
 715         ** "value" is the Epoch-relative time of 00:00:00 UTC on the day in
 716         ** question.  To get the Epoch-relative time of the specified local
 717         ** time on that day, add the transition time and the current offset
 718         ** from UTC.
 719         */
 720         return value + rulep->r_time + offset;
 721 }
 722
 723 /*
 724 ** Given a POSIX section 8-style TZ string, fill in the rule tables as
 725 ** appropriate.
 726 */
 727
 728 static int
 729 tzparse(name, sp, lastditch)
 730 const char *                    name;
 731 struct state * const    sp;
 732 const int                       lastditch;
 733 {
 734         const char *                    stdname;
 735         const char *                    dstname;
 736         size_t                          stdlen;
 737         size_t                          dstlen;
 738         long                            stdoffset;
 739         long                            dstoffset;
 740         time_t *                atp;
 741         unsigned char * typep;
 742         char *                  cp;
 743         int                     load_result;
 744
 745         INITIALIZE(dstname);
 746         stdname = name;
 747         if (lastditch) {
 748                 stdlen = strlen(name);  /* length of standard zone name */
 749                 name += stdlen;
 750                 if (stdlen >= sizeof sp->chars)
 751                         stdlen = (sizeof sp->chars) - 1;
 752                 stdoffset = 0;
 753         } else {
 754                 name = getzname(name);
 755                 stdlen = name - stdname;
 756                 if (stdlen < 3)
 757                         return -1;
 758                 if (*name == '\0')
 759                         return -1;      /* was "stdoffset = 0;" */
 760                 else {
 761                         name = getoffset(name, &stdoffset);
 762                         if (name == NULL)
 763                                 return -1;
 764                 }
 765         }
 766         load_result = tzload(TZDEFRULES, sp);
 767         if (load_result != 0)
 768                 sp->leapcnt = 0;                /* so, we're off a little */
 769         if (*name != '\0') {
 770                 dstname = name;
 771                 name = getzname(name);
 772                 dstlen = name - dstname;        /* length of DST zone name */
 773                 if (dstlen < 3)
 774                         return -1;
 775                 if (*name != '\0' && *name != ',' && *name != ';') {
 776                         name = getoffset(name, &dstoffset);
 777                         if (name == NULL)
 778                                 return -1;
 779                 } else  dstoffset = stdoffset - SECSPERHOUR;
 780                 if (*name == '\0' && load_result != 0)
 781                         name = TZDEFRULESTRING;
 782                 if (*name == ',' || *name == ';') {
 783                         struct rule     start;
 784                         struct rule     end;
 785                         int     year;
 786                         time_t  janfirst;
 787                         time_t          starttime;
 788                         time_t          endtime;
 789
 790                         ++name;
 791                         if ((name = getrule(name, &start)) == NULL)
 792                                 return -1;
 793                         if (*name++ != ',')
 794                                 return -1;
 795                         if ((name = getrule(name, &end)) == NULL)
 796                                 return -1;
 797                         if (*name != '\0')
 798                                 return -1;
 799                         sp->typecnt = 2;        /* standard time and DST */
 800                         /*
 801                         ** Two transitions per year, from EPOCH_YEAR to 2037.
 802                         */
 803                         sp->timecnt = 2 * (2037 - EPOCH_YEAR + 1);
 804                         if (sp->timecnt > TZ_MAX_TIMES)
 805                                 return -1;
 806                         sp->ttis[0].tt_gmtoff = -dstoffset;
 807                         sp->ttis[0].tt_isdst = 1;
 808                         sp->ttis[0].tt_abbrind = stdlen + 1;
 809                         sp->ttis[1].tt_gmtoff = -stdoffset;
 810                         sp->ttis[1].tt_isdst = 0;
 811                         sp->ttis[1].tt_abbrind = 0;
 812                         atp = sp->ats;
 813                         typep = sp->types;
 814                         janfirst = 0;
 815                         for (year = EPOCH_YEAR; year <= 2037; ++year) {
 816                                 starttime = transtime(janfirst, year, &start,
 817                                         stdoffset);
 818                                 endtime = transtime(janfirst, year, &end,
 819                                         dstoffset);
 820                                 if (starttime > endtime) {
 821                                         *atp++ = endtime;
 822                                         *typep++ = 1;   /* DST ends */
 823                                         *atp++ = starttime;
 824                                         *typep++ = 0;   /* DST begins */
 825                                 } else {
 826                                         *atp++ = starttime;
 827                                         *typep++ = 0;   /* DST begins */
 828                                         *atp++ = endtime;
 829                                         *typep++ = 1;   /* DST ends */
 830                                 }
 831                                 janfirst += year_lengths[isleap(year)] *
 832                                         SECSPERDAY;
 833                         }
 834                 } else {
 835                         long    theirstdoffset;
 836                         long    theirdstoffset;
 837                         long    theiroffset;
 838                         int     isdst;
 839                         int     i;
 840                         int     j;
 841
 842                         if (*name != '\0')
 843                                 return -1;
 844                         /*
 845                         ** Initial values of theirstdoffset and theirdstoffset.
 846                         */
 847                         theirstdoffset = 0;
 848                         for (i = 0; i < sp->timecnt; ++i) {
 849                                 j = sp->types[i];
 850                                 if (!sp->ttis[j].tt_isdst) {
 851                                         theirstdoffset =
 852                                                 -sp->ttis[j].tt_gmtoff;
 853                                         break;
 854                                 }
 855                         }
 856                         theirdstoffset = 0;
 857                         for (i = 0; i < sp->timecnt; ++i) {
 858                                 j = sp->types[i];
 859                                 if (sp->ttis[j].tt_isdst) {
 860                                         theirdstoffset =
 861                                                 -sp->ttis[j].tt_gmtoff;
 862                                         break;
 863                                 }
 864                         }
 865                         /*
 866                         ** Initially we're assumed to be in standard time.
 867                         */
 868                         isdst = FALSE;
 869                         theiroffset = theirstdoffset;
 870                         /*
 871                         ** Now juggle transition times and types
 872                         ** tracking offsets as you do.
 873                         */
 874                         for (i = 0; i < sp->timecnt; ++i) {
 875                                 j = sp->types[i];
 876                                 sp->types[i] = sp->ttis[j].tt_isdst;
 877                                 if (sp->ttis[j].tt_ttisgmt) {
 878                                         /* No adjustment to transition time */
 879                                 } else {
 880                                         /*
 881                                         ** If summer time is in effect, and the
 882                                         ** transition time was not specified as
 883                                         ** standard time, add the summer time
 884                                         ** offset to the transition time;
 885                                         ** otherwise, add the standard time
 886                                         ** offset to the transition time.
 887                                         */
 888                                         /*
 889                                         ** Transitions from DST to DDST
 890                                         ** will effectively disappear since
 891                                         ** POSIX provides for only one DST
 892                                         ** offset.
 893                                         */
 894                                         if (isdst && !sp->ttis[j].tt_ttisstd) {
 895                                                 sp->ats[i] += dstoffset -
 896                                                         theirdstoffset;
 897                                         } else {
 898                                                 sp->ats[i] += stdoffset -
 899                                                         theirstdoffset;
 900                                         }
 901                                 }
 902                                 theiroffset = -sp->ttis[j].tt_gmtoff;
 903                                 if (sp->ttis[j].tt_isdst)
 904                                         theirdstoffset = theiroffset;
 905                                 else    theirstdoffset = theiroffset;
 906                         }
 907                         /*
 908                         ** Finally, fill in ttis.
 909                         ** ttisstd and ttisgmt need not be handled.
 910                         */
 911                         sp->ttis[0].tt_gmtoff = -stdoffset;
 912                         sp->ttis[0].tt_isdst = FALSE;
 913                         sp->ttis[0].tt_abbrind = 0;
 914                         sp->ttis[1].tt_gmtoff = -dstoffset;
 915                         sp->ttis[1].tt_isdst = TRUE;
 916                         sp->ttis[1].tt_abbrind = stdlen + 1;
 917                         sp->typecnt = 2;
 918                 }
 919         } else {
 920                 dstlen = 0;
 921                 sp->typecnt = 1;                /* only standard time */
 922                 sp->timecnt = 0;
 923                 sp->ttis[0].tt_gmtoff = -stdoffset;
 924                 sp->ttis[0].tt_isdst = 0;
 925                 sp->ttis[0].tt_abbrind = 0;
 926         }
 927         sp->charcnt = stdlen + 1;
 928         if (dstlen != 0)
 929                 sp->charcnt += dstlen + 1;
 930         if ((size_t) sp->charcnt > sizeof sp->chars)
 931                 return -1;
 932         cp = sp->chars;
 933         (void) strncpy(cp, stdname, stdlen);
 934         cp += stdlen;
 935         *cp++ = '\0';
 936         if (dstlen != 0) {
 937                 (void) strncpy(cp, dstname, dstlen);
 938                 *(cp + dstlen) = '\0';
 939         }
 940         return 0;
 941 }
 942
 943 static void
 944 gmtload(sp)
 945 struct state * const    sp;
 946 {
 947         if (tzload(gmt, sp) != 0)
 948                 (void) tzparse(gmt, sp, TRUE);
 949 }
 950
 951 static void
 952 tzsetwall_basic(void)
 953 {
 954         if (lcl_is_set < 0)
 955                 return;
 956         lcl_is_set = -1;
 957
 958 #ifdef ALL_STATE
 959         if (lclptr == NULL) {
 960                 lclptr = (struct state *) malloc(sizeof *lclptr);
 961                 if (lclptr == NULL) {
 962                         settzname();    /* all we can do */
 963                         return;
 964                 }
 965         }
 966 #endif /* defined ALL_STATE */
 967         if (tzload((char *) NULL, lclptr) != 0)
 968                 gmtload(lclptr);
 969         settzname();
 970 }
 971
 972 void
 973 tzsetwall(void)
 974 {
 975         _MUTEX_LOCK(&lcl_mutex);
 976         tzsetwall_basic();
 977         _MUTEX_UNLOCK(&lcl_mutex);
 978 }
 979
 980 static void
 981 tzset_basic(void)
 982 {
 983         const char *    name;
 984
 985         name = getenv("TZ");
 986         if (name == NULL) {
 987                 tzsetwall_basic();
 988                 return;
 989         }
 990
 991         if (lcl_is_set > 0 && strcmp(lcl_TZname, name) == 0)
 992                 return;
 993         lcl_is_set = strlen(name) < sizeof lcl_TZname;
 994         if (lcl_is_set)
 995                 (void) strcpy(lcl_TZname, name);
 996
 997 #ifdef ALL_STATE
 998         if (lclptr == NULL) {
 999                 lclptr = (struct state *) malloc(sizeof *lclptr);
1000                 if (lclptr == NULL) {
1001                         settzname();    /* all we can do */
1002                         return;
1003                 }
1004         }
1005 #endif /* defined ALL_STATE */
1006         if (*name == '\0') {
1007                 /*
1008                 ** User wants it fast rather than right.
1009                 */
1010                 lclptr->leapcnt = 0;            /* so, we're off a little */
1011                 lclptr->timecnt = 0;
1012                 lclptr->typecnt = 0;
1013                 lclptr->ttis[0].tt_isdst = 0;
1014                 lclptr->ttis[0].tt_gmtoff = 0;
1015                 lclptr->ttis[0].tt_abbrind = 0;
1016                 (void) strcpy(lclptr->chars, gmt);
1017         } else if (tzload(name, lclptr) != 0)
1018                 if (name[0] == ':' || tzparse(name, lclptr, FALSE) != 0)
1019                         (void) gmtload(lclptr);
1020         settzname();
1021 }
1022
1023 void
1024 tzset(void)
1025 {
1026         _MUTEX_LOCK(&lcl_mutex);
1027         tzset_basic();
1028         _MUTEX_UNLOCK(&lcl_mutex);
1029 }
1030
1031 /*
1032 ** The easy way to behave "as if no library function calls" localtime
1033 ** is to not call it--so we drop its guts into "localsub", which can be
1034 ** freely called.  (And no, the PANS doesn't require the above behavior--
1035 ** but it *is* desirable.)
1036 **
1037 ** The unused offset argument is for the benefit of mktime variants.
1038 */
1039
1040 /*ARGSUSED*/
1041 static void
1042 localsub(timep, offset, tmp)
1043 const time_t * const    timep;
1044 const long              offset;
1045 struct tm * const       tmp;
1046 {
1047         struct state *          sp;
1048         const struct ttinfo *   ttisp;
1049         int                     i;
1050         const time_t                    t = *timep;
1051
1052         sp = lclptr;
1053 #ifdef ALL_STATE
1054         if (sp == NULL) {
1055                 gmtsub(timep, offset, tmp);
1056                 return;
1057         }
1058 #endif /* defined ALL_STATE */
1059         if (sp->timecnt == 0 || t < sp->ats[0]) {
1060                 i = 0;
1061                 while (sp->ttis[i].tt_isdst)
1062                         if (++i >= sp->typecnt) {
1063                                 i = 0;
1064                                 break;
1065                         }
1066         } else {
1067                 for (i = 1; i < sp->timecnt; ++i)
1068                         if (t < sp->ats[i])
1069                                 break;
1070                 i = sp->types[i - 1];
1071         }
1072         ttisp = &sp->ttis[i];
1073         /*
1074         ** To get (wrong) behavior that's compatible with System V Release 2.0
1075         ** you'd replace the statement below with
1076         **      t += ttisp->tt_gmtoff;
1077         **      timesub(&t, 0L, sp, tmp);
1078         */
1079         timesub(&t, ttisp->tt_gmtoff, sp, tmp);
1080         tmp->tm_isdst = ttisp->tt_isdst;
1081         tzname[tmp->tm_isdst] = &sp->chars[ttisp->tt_abbrind];
1082 #ifdef TM_ZONE
1083         tmp->TM_ZONE = &sp->chars[ttisp->tt_abbrind];
1084 #endif /* defined TM_ZONE */
1085 }
1086
1087 struct tm *
1088 localtime(timep)
1089 const time_t * const    timep;
1090 {
1091         static pthread_mutex_t localtime_mutex = PTHREAD_MUTEX_INITIALIZER;
1092         static pthread_key_t localtime_key = -1;
1093         struct tm *p_tm;
1094
1095         if (__isthreaded != 0) {
1096                 _pthread_mutex_lock(&localtime_mutex);
1097                 if (localtime_key < 0) {
1098                         if (_pthread_key_create(&localtime_key, free) < 0) {
1099                                 _pthread_mutex_unlock(&localtime_mutex);
1100                                 return(NULL);
1101                         }
1102                 }
1103                 _pthread_mutex_unlock(&localtime_mutex);
1104                 p_tm = _pthread_getspecific(localtime_key);
1105                 if (p_tm == NULL) {
1106                         if ((p_tm = (struct tm *)malloc(sizeof(struct tm)))
1107                             == NULL)
1108                                 return(NULL);
1109                         _pthread_setspecific(localtime_key, p_tm);
1110                 }
1111                 _pthread_mutex_lock(&lcl_mutex);
1112                 tzset_basic();
1113                 localsub(timep, 0L, p_tm);
1114                 _pthread_mutex_unlock(&lcl_mutex);
1115                 return(p_tm);
1116         } else {
1117                 tzset_basic();
1118                 localsub(timep, 0L, &tm);
1119                 return(&tm);
1120         }
1121 }
1122
1123 /*
1124 ** Re-entrant version of localtime.
1125 */
1126
1127 struct tm *
1128 localtime_r(timep, tm)
1129 const time_t * const    timep;
1130 struct tm *             tm;
1131 {
1132         _MUTEX_LOCK(&lcl_mutex);
1133         tzset_basic();
1134         localsub(timep, 0L, tm);
1135         _MUTEX_UNLOCK(&lcl_mutex);
1136         return tm;
1137 }
1138
1139 /*
1140 ** gmtsub is to gmtime as localsub is to localtime.
1141 */
1142
1143 static void
1144 gmtsub(timep, offset, tmp)
1145 const time_t * const    timep;
1146 const long              offset;
1147 struct tm * const       tmp;
1148 {
1149         _MUTEX_LOCK(&gmt_mutex);
1150         if (!gmt_is_set) {
1151                 gmt_is_set = TRUE;
1152 #ifdef ALL_STATE
1153                 gmtptr = (struct state *) malloc(sizeof *gmtptr);
1154                 if (gmtptr != NULL)
1155 #endif /* defined ALL_STATE */
1156                         gmtload(gmtptr);
1157         }
1158         _MUTEX_UNLOCK(&gmt_mutex);
1159         timesub(timep, offset, gmtptr, tmp);
1160 #ifdef TM_ZONE
1161         /*
1162         ** Could get fancy here and deliver something such as
1163         ** "UTC+xxxx" or "UTC-xxxx" if offset is non-zero,
1164         ** but this is no time for a treasure hunt.
1165         */
1166         if (offset != 0)
1167                 tmp->TM_ZONE = wildabbr;
1168         else {
1169 #ifdef ALL_STATE
1170                 if (gmtptr == NULL)
1171                         tmp->TM_ZONE = gmt;
1172                 else    tmp->TM_ZONE = gmtptr->chars;
1173 #endif /* defined ALL_STATE */
1174 #ifndef ALL_STATE
1175                 tmp->TM_ZONE = gmtptr->chars;
1176 #endif /* State Farm */
1177         }
1178 #endif /* defined TM_ZONE */
1179 }
1180
1181 struct tm *
1182 gmtime(timep)
1183 const time_t * const    timep;
1184 {
1185         static pthread_mutex_t gmtime_mutex = PTHREAD_MUTEX_INITIALIZER;
1186         static pthread_key_t gmtime_key = -1;
1187         struct tm *p_tm;
1188
1189         if (__isthreaded != 0) {
1190                 _pthread_mutex_lock(&gmtime_mutex);
1191                 if (gmtime_key < 0) {
1192                         if (_pthread_key_create(&gmtime_key, free) < 0) {
1193                                 _pthread_mutex_unlock(&gmtime_mutex);
1194                                 return(NULL);
1195                         }
1196                 }
1197                 _pthread_mutex_unlock(&gmtime_mutex);
1198                 /*
1199                  * Changed to follow POSIX.1 threads standard, which
1200                  * is what BSD currently has.
1201                  */
1202                 if ((p_tm = _pthread_getspecific(gmtime_key)) == NULL) {
1203                         if ((p_tm = (struct tm *)malloc(sizeof(struct tm)))
1204                             == NULL) {
1205                                 return(NULL);
1206                         }
1207                         _pthread_setspecific(gmtime_key, p_tm);
1208                 }
1209                 gmtsub(timep, 0L, p_tm);
1210                 return(p_tm);
1211         }
1212         else {
1213                 gmtsub(timep, 0L, &tm);
1214                 return(&tm);
1215         }
1216 }
1217
1218 /*
1219 * Re-entrant version of gmtime.
1220 */
1221
1222 struct tm *
1223 gmtime_r(timep, tm)
1224 const time_t * const    timep;
1225 struct tm *             tm;
1226 {
1227         gmtsub(timep, 0L, tm);
1228         return tm;
1229 }
1230
1231 #ifdef STD_INSPIRED
1232
1233 struct tm *
1234 offtime(timep, offset)
1235 const time_t * const    timep;
1236 const long              offset;
1237 {
1238         gmtsub(timep, offset, &tm);
1239         return &tm;
1240 }
1241
1242 #endif /* defined STD_INSPIRED */
1243
1244 static void
1245 timesub(timep, offset, sp, tmp)
1246 const time_t * const                    timep;
1247 const long                              offset;
1248 const struct state * const      sp;
1249 struct tm * const               tmp;
1250 {
1251         const struct lsinfo *   lp;
1252         long                    days;
1253         long                    rem;
1254         long                    y;
1255         int                     yleap;
1256         const int *             ip;
1257         long                    corr;
1258         int                     hit;
1259         int                     i;
1260
1261         corr = 0;
1262         hit = 0;
1263 #ifdef ALL_STATE
1264         i = (sp == NULL) ? 0 : sp->leapcnt;
1265 #endif /* defined ALL_STATE */
1266 #ifndef ALL_STATE
1267         i = sp->leapcnt;
1268 #endif /* State Farm */
1269         while (--i >= 0) {
1270                 lp = &sp->lsis[i];
1271                 if (*timep >= lp->ls_trans) {
1272                         if (*timep == lp->ls_trans) {
1273                                 hit = ((i == 0 && lp->ls_corr > 0) ||
1274                                         lp->ls_corr > sp->lsis[i - 1].ls_corr);
1275                                 if (hit)
1276                                         while (i > 0 &&
1277                                                 sp->lsis[i].ls_trans ==
1278                                                 sp->lsis[i - 1].ls_trans + 1 &&
1279                                                 sp->lsis[i].ls_corr ==
1280                                                 sp->lsis[i - 1].ls_corr + 1) {
1281                                                         ++hit;
1282                                                         --i;
1283                                         }
1284                         }
1285                         corr = lp->ls_corr;
1286                         break;
1287                 }
1288         }
1289         days = *timep / SECSPERDAY;
1290         rem = *timep % SECSPERDAY;
1291 #ifdef mc68k
1292         if (*timep == 0x80000000) {
1293                 /*
1294                 ** A 3B1 muffs the division on the most negative number.
1295                 */
1296                 days = -24855;
1297                 rem = -11648;
1298         }
1299 #endif /* defined mc68k */
1300         rem += (offset - corr);
1301         while (rem < 0) {
1302                 rem += SECSPERDAY;
1303                 --days;
1304         }
1305         while (rem >= SECSPERDAY) {
1306                 rem -= SECSPERDAY;
1307                 ++days;
1308         }
1309         tmp->tm_hour = (int) (rem / SECSPERHOUR);
1310         rem = rem % SECSPERHOUR;
1311         tmp->tm_min = (int) (rem / SECSPERMIN);
1312         /*
1313         ** A positive leap second requires a special
1314         ** representation.  This uses "... ??:59:60" et seq.
1315         */
1316         tmp->tm_sec = (int) (rem % SECSPERMIN) + hit;
1317         tmp->tm_wday = (int) ((EPOCH_WDAY + days) % DAYSPERWEEK);
1318         if (tmp->tm_wday < 0)
1319                 tmp->tm_wday += DAYSPERWEEK;
1320         y = EPOCH_YEAR;
1321 #define LEAPS_THRU_END_OF(y)    ((y) / 4 - (y) / 100 + (y) / 400)
1322         while (days < 0 || days >= (long) year_lengths[yleap = isleap(y)]) {
1323                 long    newy;
1324
1325                 newy = y + days / DAYSPERNYEAR;
1326                 if (days < 0)
1327                         --newy;
1328                 days -= (newy - y) * DAYSPERNYEAR +
1329                         LEAPS_THRU_END_OF(newy - 1) -
1330                         LEAPS_THRU_END_OF(y - 1);
1331                 y = newy;
1332         }
1333         tmp->tm_year = y - TM_YEAR_BASE;
1334         tmp->tm_yday = (int) days;
1335         ip = mon_lengths[yleap];
1336         for (tmp->tm_mon = 0; days >= (long) ip[tmp->tm_mon]; ++(tmp->tm_mon))
1337                 days = days - (long) ip[tmp->tm_mon];
1338         tmp->tm_mday = (int) (days + 1);
1339         tmp->tm_isdst = 0;
1340 #ifdef TM_GMTOFF
1341         tmp->TM_GMTOFF = offset;
1342 #endif /* defined TM_GMTOFF */
1343 }
1344
1345 char *
1346 ctime(timep)
1347 const time_t * const    timep;
1348 {
1349 /*
1350 ** Section 4.12.3.2 of X3.159-1989 requires that
1351 **      The ctime function converts the calendar time pointed to by timer
1352 **      to local time in the form of a string.  It is equivalent to
1353 **              asctime(localtime(timer))
1354 */
1355         return asctime(localtime(timep));
1356 }
1357
1358 char *
1359 ctime_r(timep, buf)
1360 const time_t * const    timep;
1361 char *                  buf;
1362 {
1363         struct tm       tm;
1364
1365         return asctime_r(localtime_r(timep, &tm), buf);
1366 }
1367
1368 /*
1369 ** Adapted from code provided by Robert Elz, who writes:
1370 **      The "best" way to do mktime I think is based on an idea of Bob
1371 **      Kridle's (so its said...) from a long time ago.
1372 **      [kridle@xinet.com as of 1996-01-16.]
1373 **      It does a binary search of the time_t space.  Since time_t's are
1374 **      just 32 bits, its a max of 32 iterations (even at 64 bits it
1375 **      would still be very reasonable).
1376 */
1377
1378 #ifndef WRONG
1379 #define WRONG   (-1)
1380 #endif /* !defined WRONG */
1381
1382 /*
1383 ** Simplified normalize logic courtesy Paul Eggert (eggert@twinsun.com).
1384 */
1385
1386 static int
1387 increment_overflow(number, delta)
1388 int *   number;
1389 int     delta;
1390 {
1391         int     number0;
1392
1393         number0 = *number;
1394         *number += delta;
1395         return (*number < number0) != (delta < 0);
1396 }
1397
1398 static int
1399 normalize_overflow(tensptr, unitsptr, base)
1400 int * const     tensptr;
1401 int * const     unitsptr;
1402 const int       base;
1403 {
1404         int     tensdelta;
1405
1406         tensdelta = (*unitsptr >= 0) ?
1407                 (*unitsptr / base) :
1408                 (-1 - (-1 - *unitsptr) / base);
1409         *unitsptr -= tensdelta * base;
1410         return increment_overflow(tensptr, tensdelta);
1411 }
1412
1413 static int
1414 tmcomp(atmp, btmp)
1415 const struct tm * const atmp;
1416 const struct tm * const btmp;
1417 {
1418         int     result;
1419
1420         if ((result = (atmp->tm_year - btmp->tm_year)) == 0 &&
1421                 (result = (atmp->tm_mon - btmp->tm_mon)) == 0 &&
1422                 (result = (atmp->tm_mday - btmp->tm_mday)) == 0 &&
1423                 (result = (atmp->tm_hour - btmp->tm_hour)) == 0 &&
1424                 (result = (atmp->tm_min - btmp->tm_min)) == 0)
1425                         result = atmp->tm_sec - btmp->tm_sec;
1426         return result;
1427 }
1428
1429 static time_t
1430 time2sub(tmp, funcp, offset, okayp, do_norm_secs)
1431 struct tm * const       tmp;
1432 void (* const           funcp)(const time_t*, long, struct tm*);
1433 const long              offset;
1434 int * const             okayp;
1435 const int               do_norm_secs;
1436 {
1437         const struct state *    sp;
1438         int                     dir;
1439         int                     bits;
1440         int                     i, j ;
1441         int                     saved_seconds;
1442         time_t                          newt;
1443         time_t                          t;
1444         struct tm                       yourtm, mytm;
1445
1446         *okayp = FALSE;
1447         yourtm = *tmp;
1448         if (do_norm_secs) {
1449                 if (normalize_overflow(&yourtm.tm_min, &yourtm.tm_sec,
1450                         SECSPERMIN))
1451                                 return WRONG;
1452         }
1453         if (normalize_overflow(&yourtm.tm_hour, &yourtm.tm_min, MINSPERHOUR))
1454                 return WRONG;
1455         if (normalize_overflow(&yourtm.tm_mday, &yourtm.tm_hour, HOURSPERDAY))
1456                 return WRONG;
1457         if (normalize_overflow(&yourtm.tm_year, &yourtm.tm_mon, MONSPERYEAR))
1458                 return WRONG;
1459         /*
1460         ** Turn yourtm.tm_year into an actual year number for now.
1461         ** It is converted back to an offset from TM_YEAR_BASE later.
1462         */
1463         if (increment_overflow(&yourtm.tm_year, TM_YEAR_BASE))
1464                 return WRONG;
1465         while (yourtm.tm_mday <= 0) {
1466                 if (increment_overflow(&yourtm.tm_year, -1))
1467                         return WRONG;
1468                 i = yourtm.tm_year + (1 < yourtm.tm_mon);
1469                 yourtm.tm_mday += year_lengths[isleap(i)];
1470         }
1471         while (yourtm.tm_mday > DAYSPERLYEAR) {
1472                 i = yourtm.tm_year + (1 < yourtm.tm_mon);
1473                 yourtm.tm_mday -= year_lengths[isleap(i)];
1474                 if (increment_overflow(&yourtm.tm_year, 1))
1475                         return WRONG;
1476         }
1477         for ( ; ; ) {
1478                 i = mon_lengths[isleap(yourtm.tm_year)][yourtm.tm_mon];
1479                 if (yourtm.tm_mday <= i)
1480                         break;
1481                 yourtm.tm_mday -= i;
1482                 if (++yourtm.tm_mon >= MONSPERYEAR) {
1483                         yourtm.tm_mon = 0;
1484                         if (increment_overflow(&yourtm.tm_year, 1))
1485                                 return WRONG;
1486                 }
1487         }
1488         if (increment_overflow(&yourtm.tm_year, -TM_YEAR_BASE))
1489                 return WRONG;
1490         /* Don't go below 1900 for POLA */
1491         if (yourtm.tm_year < 0)
1492                 return WRONG;
1493         if (yourtm.tm_sec >= 0 && yourtm.tm_sec < SECSPERMIN)
1494                 saved_seconds = 0;
1495         else if (yourtm.tm_year + TM_YEAR_BASE < EPOCH_YEAR) {
1496                 /*
1497                 ** We can't set tm_sec to 0, because that might push the
1498                 ** time below the minimum representable time.
1499                 ** Set tm_sec to 59 instead.
1500                 ** This assumes that the minimum representable time is
1501                 ** not in the same minute that a leap second was deleted from,
1502                 ** which is a safer assumption than using 58 would be.
1503                 */
1504                 if (increment_overflow(&yourtm.tm_sec, 1 - SECSPERMIN))
1505                         return WRONG;
1506                 saved_seconds = yourtm.tm_sec;
1507                 yourtm.tm_sec = SECSPERMIN - 1;
1508         } else {
1509                 saved_seconds = yourtm.tm_sec;
1510                 yourtm.tm_sec = 0;
1511         }
1512         /*
1513         ** Divide the search space in half
1514         ** (this works whether time_t is signed or unsigned).
1515         */
1516         bits = TYPE_BIT(time_t) - 1;
1517         /*
1518         ** If we have more than this, we will overflow tm_year for tmcomp().
1519         ** We should really return an error if we cannot represent it.
1520         */
1521         if (bits > 56)
1522                 bits = 56;
1523         /*
1524         ** If time_t is signed, then 0 is just above the median,
1525         ** assuming two's complement arithmetic.
1526         ** If time_t is unsigned, then (1 << bits) is just above the median.
1527         */
1528         t = TYPE_SIGNED(time_t) ? 0 : (((time_t) 1) << bits);
1529         for ( ; ; ) {
1530                 (*funcp)(&t, offset, &mytm);
1531                 dir = tmcomp(&mytm, &yourtm);
1532                 if (dir != 0) {
1533                         if (bits-- < 0)
1534                                 return WRONG;
1535                         if (bits < 0)
1536                                 --t; /* may be needed if new t is minimal */
1537                         else if (dir > 0)
1538                                 t -= ((time_t) 1) << bits;
1539                         else    t += ((time_t) 1) << bits;
1540                         continue;
1541                 }
1542                 if (yourtm.tm_isdst < 0 || mytm.tm_isdst == yourtm.tm_isdst)
1543                         break;
1544                 /*
1545                 ** Right time, wrong type.
1546                 ** Hunt for right time, right type.
1547                 ** It's okay to guess wrong since the guess
1548                 ** gets checked.
1549                 */
1550                 sp = (funcp == localsub) ? lclptr : gmtptr;
1551 #ifdef ALL_STATE
1552                 if (sp == NULL)
1553                         return WRONG;
1554 #endif /* defined ALL_STATE */
1555                 for (i = sp->typecnt - 1; i >= 0; --i) {
1556                         if (sp->ttis[i].tt_isdst != yourtm.tm_isdst)
1557                                 continue;
1558                         for (j = sp->typecnt - 1; j >= 0; --j) {
1559                                 if (sp->ttis[j].tt_isdst == yourtm.tm_isdst)
1560                                         continue;
1561                                 newt = t + sp->ttis[j].tt_gmtoff -
1562                                         sp->ttis[i].tt_gmtoff;
1563                                 (*funcp)(&newt, offset, &mytm);
1564                                 if (tmcomp(&mytm, &yourtm) != 0)
1565                                         continue;
1566                                 if (mytm.tm_isdst != yourtm.tm_isdst)
1567                                         continue;
1568                                 /*
1569                                 ** We have a match.
1570                                 */
1571                                 t = newt;
1572                                 goto label;
1573                         }
1574                 }
1575                 return WRONG;
1576         }
1577 label:
1578         newt = t + saved_seconds;
1579         if ((newt < t) != (saved_seconds < 0))
1580                 return WRONG;
1581         t = newt;
1582         (*funcp)(&t, offset, tmp);
1583         *okayp = TRUE;
1584         return t;
1585 }
1586
1587 static time_t
1588 time2(tmp, funcp, offset, okayp)
1589 struct tm * const       tmp;
1590 void (* const           funcp)(const time_t*, long, struct tm*);
1591 const long              offset;
1592 int * const             okayp;
1593 {
1594         time_t  t;
1595
1596         /*
1597         ** First try without normalization of seconds
1598         ** (in case tm_sec contains a value associated with a leap second).
1599         ** If that fails, try with normalization of seconds.
1600         */
1601         t = time2sub(tmp, funcp, offset, okayp, FALSE);
1602         return *okayp ? t : time2sub(tmp, funcp, offset, okayp, TRUE);
1603 }
1604
1605 static time_t
1606 time1(tmp, funcp, offset)
1607 struct tm * const       tmp;
1608 void (* const           funcp)(const time_t *, long, struct tm *);
1609 const long              offset;
1610 {
1611         time_t                  t;
1612         const struct state *    sp;
1613         int                     samei, otheri;
1614         int                     sameind, otherind;
1615         int                     i;
1616         int                     nseen;
1617         int                             seen[TZ_MAX_TYPES];
1618         int                             types[TZ_MAX_TYPES];
1619         int                             okay;
1620
1621         if (tmp->tm_isdst > 1)
1622                 tmp->tm_isdst = 1;
1623         t = time2(tmp, funcp, offset, &okay);
1624 #ifdef PCTS
1625         /*
1626         ** PCTS code courtesy Grant Sullivan (grant@osf.org).
1627         */
1628         if (okay)
1629                 return t;
1630         if (tmp->tm_isdst < 0)
1631                 tmp->tm_isdst = 0;      /* reset to std and try again */
1632 #endif /* defined PCTS */
1633 #ifndef PCTS
1634         if (okay || tmp->tm_isdst < 0)
1635                 return t;
1636 #endif /* !defined PCTS */
1637         /*
1638         ** We're supposed to assume that somebody took a time of one type
1639         ** and did some math on it that yielded a "struct tm" that's bad.
1640         ** We try to divine the type they started from and adjust to the
1641         ** type they need.
1642         */
1643         sp = (funcp == localsub) ? lclptr : gmtptr;
1644 #ifdef ALL_STATE
1645         if (sp == NULL)
1646                 return WRONG;
1647 #endif /* defined ALL_STATE */
1648         for (i = 0; i < sp->typecnt; ++i)
1649                 seen[i] = FALSE;
1650         nseen = 0;
1651         for (i = sp->timecnt - 1; i >= 0; --i)
1652                 if (!seen[sp->types[i]]) {
1653                         seen[sp->types[i]] = TRUE;
1654                         types[nseen++] = sp->types[i];
1655                 }
1656         for (sameind = 0; sameind < nseen; ++sameind) {
1657                 samei = types[sameind];
1658                 if (sp->ttis[samei].tt_isdst != tmp->tm_isdst)
1659                         continue;
1660                 for (otherind = 0; otherind < nseen; ++otherind) {
1661                         otheri = types[otherind];
1662                         if (sp->ttis[otheri].tt_isdst == tmp->tm_isdst)
1663                                 continue;
1664                         tmp->tm_sec += sp->ttis[otheri].tt_gmtoff -
1665                                         sp->ttis[samei].tt_gmtoff;
1666                         tmp->tm_isdst = !tmp->tm_isdst;
1667                         t = time2(tmp, funcp, offset, &okay);
1668                         if (okay)
1669                                 return t;
1670                         tmp->tm_sec -= sp->ttis[otheri].tt_gmtoff -
1671                                         sp->ttis[samei].tt_gmtoff;
1672                         tmp->tm_isdst = !tmp->tm_isdst;
1673                 }
1674         }
1675         return WRONG;
1676 }
1677
1678 time_t
1679 mktime(tmp)
1680 struct tm * const       tmp;
1681 {
1682         time_t mktime_return_value;
1683         _MUTEX_LOCK(&lcl_mutex);
1684         tzset_basic();
1685         mktime_return_value = time1(tmp, localsub, 0L);
1686         _MUTEX_UNLOCK(&lcl_mutex);
1687         return(mktime_return_value);
1688 }
1689
1690 #ifdef STD_INSPIRED
1691
1692 time_t
1693 timelocal(tmp)
1694 struct tm * const       tmp;
1695 {
1696         tmp->tm_isdst = -1;     /* in case it wasn't initialized */
1697         return mktime(tmp);
1698 }
1699
1700 time_t
1701 timegm(tmp)
1702 struct tm * const       tmp;
1703 {
1704         tmp->tm_isdst = 0;
1705         return time1(tmp, gmtsub, 0L);
1706 }
1707
1708 time_t
1709 timeoff(tmp, offset)
1710 struct tm * const       tmp;
1711 const long              offset;
1712 {
1713         tmp->tm_isdst = 0;
1714         return time1(tmp, gmtsub, offset);
1715 }
1716
1717 #endif /* defined STD_INSPIRED */
1718
1719 #ifdef CMUCS
1720
1721 /*
1722 ** The following is supplied for compatibility with
1723 ** previous versions of the CMUCS runtime library.
1724 */
1725
1726 long
1727 gtime(tmp)
1728 struct tm * const       tmp;
1729 {
1730         const time_t    t = mktime(tmp);
1731
1732         if (t == WRONG)
1733                 return -1;
1734         return t;
1735 }
1736
1737 #endif /* defined CMUCS */
1738
1739 /*
1740 ** XXX--is the below the right way to conditionalize??
1741 */
1742
1743 #ifdef STD_INSPIRED
1744
1745 /*
1746 ** IEEE Std 1003.1-1988 (POSIX) legislates that 536457599
1747 ** shall correspond to "Wed Dec 31 23:59:59 UTC 1986", which
1748 ** is not the case if we are accounting for leap seconds.
1749 ** So, we provide the following conversion routines for use
1750 ** when exchanging timestamps with POSIX conforming systems.
1751 */
1752
1753 static long
1754 leapcorr(timep)
1755 time_t *        timep;
1756 {
1757         struct state *          sp;
1758         struct lsinfo * lp;
1759         int                     i;
1760
1761         sp = lclptr;
1762         i = sp->leapcnt;
1763         while (--i >= 0) {
1764                 lp = &sp->lsis[i];
1765                 if (*timep >= lp->ls_trans)
1766                         return lp->ls_corr;
1767         }
1768         return 0;
1769 }
1770
1771 time_t
1772 time2posix(t)
1773 time_t  t;
1774 {
1775         tzset();
1776         return t - leapcorr(&t);
1777 }
1778
1779 time_t
1780 posix2time(t)
1781 time_t  t;
1782 {
1783         time_t  x;
1784         time_t  y;
1785
1786         tzset();
1787         /*
1788         ** For a positive leap second hit, the result
1789         ** is not unique.  For a negative leap second
1790         ** hit, the corresponding time doesn't exist,
1791         ** so we return an adjacent second.
1792         */
1793         x = t + leapcorr(&t);
1794         y = x - leapcorr(&x);
1795         if (y < t) {
1796                 do {
1797                         x++;
1798                         y = x - leapcorr(&x);
1799                 } while (y < t);
1800                 if (t != y)
1801                         return x - 1;
1802         } else if (y > t) {
1803                 do {
1804                         --x;
1805                         y = x - leapcorr(&x);
1806                 } while (y > t);
1807                 if (t != y)
1808                         return x + 1;
1809         }
1810         return x;
1811 }
1812
1813 #endif /* defined STD_INSPIRED */