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localtimedb.c
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localtimedb.c
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/*
** This file is in the public domain, so clarified as of
** 1996-06-05 by Arthur David Olson.
*/
#include "printformats.h"
#ifndef lint
#ifndef NOID
//static char elsieid[] = "@(#)localtime.c 8.5";
#endif /* !defined NOID */
#endif /* !defined lint */
/*
** Leap second handling from Bradley White.
** POSIX-style TZ environment variable handling from Guy Harris.
*/
/*LINTLIBRARY*/
#include <strings.h>
#include <assert.h>
#include <errno.h>
#include "private.h"
#include "tzfile.h"
#include "fcntl.h"
#include "float.h" /* for FLT_MAX and DBL_MAX */
#include "mem_datetime.h"
#include "mem_override.h"
#include "logmsg.h"
#include "locks_wrap.h"
#include <str0.h>
#ifndef TZ_ABBR_MAX_LEN
#define TZ_ABBR_MAX_LEN 16
#endif /* !defined TZ_ABBR_MAX_LEN */
#ifndef TZ_ABBR_CHAR_SET
#define TZ_ABBR_CHAR_SET \
"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789 :+-._"
#endif /* !defined TZ_ABBR_CHAR_SET */
#ifndef TZ_ABBR_ERR_CHAR
#define TZ_ABBR_ERR_CHAR '_'
#endif /* !defined TZ_ABBR_ERR_CHAR */
/*
** SunOS 4.1.1 headers lack O_BINARY.
*/
#ifdef O_BINARY
#define OPEN_MODE (O_RDONLY | O_BINARY)
#endif /* defined O_BINARY */
#ifndef O_BINARY
#define OPEN_MODE O_RDONLY
#endif /* !defined O_BINARY */
#ifndef WILDABBR
/*
** Someone might make incorrect use of a time zone abbreviation:
** 1. They might reference tzname[0] before calling tzset (explicitly
** or implicitly).
** 2. They might reference tzname[1] before calling tzset (explicitly
** or implicitly).
** 3. They might reference tzname[1] after setting to a time zone
** in which Daylight Saving Time is never observed.
** 4. They might reference tzname[0] after setting to a time zone
** in which Standard Time is never observed.
** 5. They might reference tm.TM_ZONE after calling offtime.
** What's best to do in the above cases is open to debate;
** for now, we just set things up so that in any of the five cases
** WILDABBR is used. Another possibility: initialize tzname[0] to the
** string "tzname[0] used before set", and similarly for the other cases.
** And another: initialize tzname[0] to "ERA", with an explanation in the
** manual page of what this "time zone abbreviation" means (doing this so
** that tzname[0] has the "normal" length of three characters).
*/
#define WILDABBR " "
#endif /* !defined WILDABBR */
static char wildabbr[] = WILDABBR;
static const char gmt[] = "GMT";
/*
** The DST rules to use if TZ has no rules and we can't load TZDEFRULES.
** We default to US rules as of 1999-08-17.
** POSIX 1003.1 section 8.1.1 says that the default DST rules are
** implementation dependent; for historical reasons, US rules are a
** common default.
*/
#ifndef TZDEFRULESTRING
#define TZDEFRULESTRING ",M4.1.0,M10.5.0"
#endif /* !defined TZDEFDST */
struct ttinfo { /* time type information */
long tt_gmtoff; /* UTC offset in seconds */
int tt_isdst; /* used to set tm_isdst */
int tt_abbrind; /* abbreviation list index */
int tt_ttisstd; /* TRUE if transition is std time */
int tt_ttisgmt; /* TRUE if transition is UTC */
};
struct lsinfo { /* leap second information */
time_t ls_trans; /* transition time */
long ls_corr; /* correction to apply */
};
#define BIGGEST(a, b) (((a) > (b)) ? (a) : (b))
#ifdef TZNAME_MAX
#define MY_TZNAME_MAX TZNAME_MAX
#endif /* defined TZNAME_MAX */
#ifndef TZNAME_MAX
#define MY_TZNAME_MAX 255
#endif /* !defined TZNAME_MAX */
struct state {
int leapcnt;
int timecnt;
int typecnt;
int charcnt;
int goback;
int goahead;
time_t ats[TZ_MAX_TIMES];
unsigned char types[TZ_MAX_TIMES];
struct ttinfo ttis[TZ_MAX_TYPES];
char chars[BIGGEST(BIGGEST(TZ_MAX_CHARS + 1, sizeof gmt),
(2 * (MY_TZNAME_MAX + 1)))];
struct lsinfo lsis[TZ_MAX_LEAPS];
};
struct rule {
int r_type; /* type of rule--see below */
int r_day; /* day number of rule */
int r_week; /* week number of rule */
int r_mon; /* month number of rule */
long r_time; /* transition time of rule */
};
#define JULIAN_DAY 0 /* Jn - Julian day */
#define DAY_OF_YEAR 1 /* n - day of year */
#define MONTH_NTH_DAY_OF_WEEK 2 /* Mm.n.d - month, week, day of week */
/*
** Prototypes for static functions.
*/
static long detzcode P((const char *codep));
static time_t detzcode64 P((const char *codep));
static int differ_by_repeat P((time_t t1, time_t t0));
static const char *getzname P((const char *strp));
static const char *getqzname P((const char *strp, const int delim));
static const char *getnum P((const char *strp, int *nump, int min, int max));
static const char *getsecs P((const char *strp, long *secsp));
static const char *getoffset P((const char *strp, long *offsetp));
static const char *getrule P((const char *strp, struct rule *rulep));
static void gmtload P((struct state * sp));
#ifdef ALL_STATE
static struct tm *gmtsub P((const time_t *timep, long offset, struct tm *tmp));
#endif
static struct tm *localsub P((const time_t *timep, long offset,
struct tm *tmp));
static int increment_overflow P((int *number, int delta));
static int leaps_thru_end_of P((int y));
static int long_increment_overflow P((long *number, int delta));
static int long_normalize_overflow P((long *tensptr, int *unitsptr, int base));
static int normalize_overflow P((int *tensptr, int *unitsptr, int base));
static void settzname P((void));
static time_t time1
P((struct tm * tmp, struct tm *(*funcp)P((const time_t *, long, struct tm *)),
long offset));
static time_t time2
P((struct tm * tmp, struct tm *(*funcp)P((const time_t *, long, struct tm *)),
long offset, int *okayp));
static time_t time2sub
P((struct tm * tmp, struct tm *(*funcp)P((const time_t *, long, struct tm *)),
long offset, int *okayp, int do_norm_secs));
static struct tm *timesub P((const time_t *timep, long offset,
const struct state *sp, struct tm *tmp));
static int tmcomp P((const struct tm *atmp, const struct tm *btmp));
static time_t transtime P((time_t janfirst, int year, const struct rule *rulep,
long offset));
static int tzload P((const char *name, struct state *sp, int doextend));
static int tzparse P((const char *name, struct state *sp, int lastditch));
#ifdef ALL_STATE
static struct state *lclptr;
static struct state *gmtptr;
#endif /* defined ALL_STATE */
#ifndef ALL_STATE
static struct state lclmem;
static struct state gmtmem;
#define lclptr (&lclmem)
#define gmtptr (&gmtmem)
#endif /* State Farm */
#ifndef TZ_STRLEN_MAX
#define TZ_STRLEN_MAX 255
#endif /* !defined TZ_STRLEN_MAX */
static char lcl_TZname[TZ_STRLEN_MAX + 1];
static int lcl_is_set;
static int gmt_is_set;
/* Information about time zone files. */
static char *tzdir;
char *tzname[2] = {wildabbr, wildabbr};
/*
** Section 4.12.3 of X3.159-1989 requires that
** Except for the strftime function, these functions [asctime,
** ctime, gmtime, localtime] return values in one of two static
** objects: a broken-down time structure and an array of char.
** Thanks to Paul Eggert for noting this.
*/
static struct tm tm;
#ifdef USG_COMPAT
time_t timezone = 0;
int daylight = 0;
#endif /* defined USG_COMPAT */
#ifdef ALTZONE
time_t altzone = 0;
#endif /* defined ALTZONE */
static long detzcode(codep) const char *const codep;
{
register long result;
register int i;
result = (codep[0] & 0x80) ? ~0L : 0;
for (i = 0; i < 4; ++i)
result = (result << 8) | (codep[i] & 0xff);
return result;
}
static time_t detzcode64(codep) const char *const codep;
{
register time_t result;
register int i;
result = (codep[0] & 0x80) ? (~(int_fast64_t)0) : 0;
for (i = 0; i < 8; ++i)
result = result * 256 + (codep[i] & 0xff);
return result;
}
static void settzname P((void))
{
register struct state *const sp = lclptr;
register int i;
tzname[0] = wildabbr;
tzname[1] = wildabbr;
#ifdef USG_COMPAT
daylight = 0;
timezone = 0;
#endif /* defined USG_COMPAT */
#ifdef ALTZONE
altzone = 0;
#endif /* defined ALTZONE */
#ifdef ALL_STATE
if (sp == NULL) {
tzname[0] = tzname[1] = gmt;
return;
}
#endif /* defined ALL_STATE */
for (i = 0; i < sp->typecnt; ++i) {
register const struct ttinfo *const ttisp = &sp->ttis[i];
tzname[ttisp->tt_isdst] = &sp->chars[ttisp->tt_abbrind];
#ifdef USG_COMPAT
if (ttisp->tt_isdst) daylight = 1;
if (i == 0 || !ttisp->tt_isdst) timezone = -(ttisp->tt_gmtoff);
#endif /* defined USG_COMPAT */
#ifdef ALTZONE
if (i == 0 || ttisp->tt_isdst) altzone = -(ttisp->tt_gmtoff);
#endif /* defined ALTZONE */
}
/*
** And to get the latest zone names into tzname. . .
*/
for (i = 0; i < sp->timecnt; ++i) {
register const struct ttinfo *const ttisp = &sp->ttis[sp->types[i]];
tzname[ttisp->tt_isdst] = &sp->chars[ttisp->tt_abbrind];
}
/*
** Finally, scrub the abbreviations.
** First, replace bogus characters.
*/
for (i = 0; i < sp->charcnt; ++i)
if (strchr(TZ_ABBR_CHAR_SET, sp->chars[i]) == NULL)
sp->chars[i] = TZ_ABBR_ERR_CHAR;
/*
** Second, truncate long abbreviations.
*/
for (i = 0; i < sp->typecnt; ++i) {
register const struct ttinfo *const ttisp = &sp->ttis[i];
register char *cp = &sp->chars[ttisp->tt_abbrind];
if (strlen(cp) > TZ_ABBR_MAX_LEN && strcmp(cp, GRANDPARENTED) != 0)
*(cp + TZ_ABBR_MAX_LEN) = '\0';
}
}
static int differ_by_repeat(t1, t0) const time_t t1;
const time_t t0;
{
if (TYPE_INTEGRAL(time_t) &&
TYPE_BIT(time_t) - TYPE_SIGNED(time_t) < SECSPERREPEAT_BITS)
return 0;
const int_fast64_t diff = t1 - t0;
return diff == SECSPERREPEAT;
}
static int tzload(name, sp, doextend) register const char *name;
register struct state *const sp;
register const int doextend;
{
register const char *p;
register int i;
register int fid;
register int stored;
register int nread;
union {
struct tzhead tzhead;
char buf[2 * sizeof(struct tzhead) + 2 * sizeof *sp + 4 * TZ_MAX_TIMES];
} u;
if (name == NULL && (name = TZDEFAULT) == NULL) return -1;
{
register int doaccess;
/*
** Section 4.9.1 of the C standard says that
** "FILENAME_MAX expands to an integral constant expression
** that is the size needed for an array of char large enough
** to hold the longest file name string that the implementation
** guarantees can be opened."
*/
/*
** For HP-UX FILENAME_MAX is assigned to 14, we wouldn't want to
** use it here.
*/
int file_max = FILENAME_MAX;
if (FILENAME_MAX < 1024) {
file_max = 1024;
}
char fullname[file_max + 1];
if (name[0] == ':') ++name;
doaccess = name[0] == '/';
if (!doaccess) {
if ((p = tzdir) == NULL) return -1;
if ((strlen(p) + strlen(name) + 1) >= sizeof fullname) return -1;
(void)strcpy(fullname, p);
(void)strcat(fullname, "/");
(void)strcat(fullname, name);
/*
** Set doaccess if '.' (as in "../") shows up in name.
*/
if (strchr(name, '.') != NULL) doaccess = TRUE;
name = fullname;
}
if (doaccess && access(name, R_OK) != 0) return -1;
if ((fid = open(name, OPEN_MODE)) == -1) return -1;
}
nread = read(fid, u.buf, sizeof u.buf);
if (close(fid) < 0 || nread <= 0) return -1;
for (stored = 4; stored <= 8; stored *= 2) {
int ttisstdcnt;
int ttisgmtcnt;
ttisstdcnt = (int)detzcode(u.tzhead.tzh_ttisstdcnt);
ttisgmtcnt = (int)detzcode(u.tzhead.tzh_ttisgmtcnt);
sp->leapcnt = (int)detzcode(u.tzhead.tzh_leapcnt);
sp->timecnt = (int)detzcode(u.tzhead.tzh_timecnt);
sp->typecnt = (int)detzcode(u.tzhead.tzh_typecnt);
sp->charcnt = (int)detzcode(u.tzhead.tzh_charcnt);
p = u.tzhead.tzh_charcnt + sizeof u.tzhead.tzh_charcnt;
if (sp->leapcnt < 0 || sp->leapcnt > TZ_MAX_LEAPS || sp->typecnt <= 0 ||
sp->typecnt > TZ_MAX_TYPES || sp->timecnt < 0 ||
sp->timecnt > TZ_MAX_TIMES || sp->charcnt < 0 ||
sp->charcnt > TZ_MAX_CHARS ||
(ttisstdcnt != sp->typecnt && ttisstdcnt != 0) ||
(ttisgmtcnt != sp->typecnt && ttisgmtcnt != 0))
return -1;
if (nread - (p - u.buf) < sp->timecnt * stored + /* ats */
sp->timecnt + /* types */
sp->typecnt * 6 + /* ttinfos */
sp->charcnt + /* chars */
sp->leapcnt * (stored + 4) + /* lsinfos */
ttisstdcnt + /* ttisstds */
ttisgmtcnt) /* ttisgmts */
return -1;
for (i = 0; i < sp->timecnt; ++i) {
sp->ats[i] = (stored == 4) ? detzcode(p) : detzcode64(p);
p += stored;
}
for (i = 0; i < sp->timecnt; ++i) {
sp->types[i] = (unsigned char)*p++;
if (sp->types[i] >= sp->typecnt) return -1;
}
for (i = 0; i < sp->typecnt; ++i) {
register struct ttinfo *ttisp;
ttisp = &sp->ttis[i];
ttisp->tt_gmtoff = detzcode(p);
p += 4;
ttisp->tt_isdst = (unsigned char)*p++;
if (ttisp->tt_isdst != 0 && ttisp->tt_isdst != 1) return -1;
ttisp->tt_abbrind = (unsigned char)*p++;
if (ttisp->tt_abbrind < 0 || ttisp->tt_abbrind > sp->charcnt)
return -1;
}
for (i = 0; i < sp->charcnt; ++i)
sp->chars[i] = *p++;
sp->chars[i] = '\0'; /* ensure '\0' at end */
for (i = 0; i < sp->leapcnt; ++i) {
register struct lsinfo *lsisp;
lsisp = &sp->lsis[i];
lsisp->ls_trans = (stored == 4) ? detzcode(p) : detzcode64(p);
p += stored;
lsisp->ls_corr = detzcode(p);
p += 4;
}
for (i = 0; i < sp->typecnt; ++i) {
register struct ttinfo *ttisp;
ttisp = &sp->ttis[i];
if (ttisstdcnt == 0)
ttisp->tt_ttisstd = FALSE;
else {
ttisp->tt_ttisstd = *p++;
if (ttisp->tt_ttisstd != TRUE && ttisp->tt_ttisstd != FALSE)
return -1;
}
}
for (i = 0; i < sp->typecnt; ++i) {
register struct ttinfo *ttisp;
ttisp = &sp->ttis[i];
if (ttisgmtcnt == 0)
ttisp->tt_ttisgmt = FALSE;
else {
ttisp->tt_ttisgmt = *p++;
if (ttisp->tt_ttisgmt != TRUE && ttisp->tt_ttisgmt != FALSE)
return -1;
}
}
/*
** Out-of-sort ats should mean we're running on a
** signed time_t system but using a data file with
** unsigned values (or vice versa).
*/
for (i = 0; i < sp->timecnt - 2; ++i)
if (sp->ats[i] > sp->ats[i + 1]) {
++i;
if (TYPE_SIGNED(time_t)) {
/*
** Ignore the end (easy).
*/
sp->timecnt = i;
} else {
/*
** Ignore the beginning (harder).
*/
register int j;
for (j = 0; j + i < sp->timecnt; ++j) {
sp->ats[j] = sp->ats[j + i];
sp->types[j] = sp->types[j + i];
}
sp->timecnt = j;
}
break;
}
/*
** If this is an old file, we're done.
*/
if (u.tzhead.tzh_version[0] == '\0') break;
nread -= p - u.buf;
for (i = 0; i < nread; ++i)
u.buf[i] = p[i];
/*
** If this is a narrow integer time_t system, we're done.
*/
if (stored >= (int)sizeof(time_t) && TYPE_INTEGRAL(time_t)) break;
}
if (doextend && nread > 2 && u.buf[0] == '\n' && u.buf[nread - 1] == '\n' &&
sp->typecnt + 2 <= TZ_MAX_TYPES) {
struct state ts;
register int result;
u.buf[nread - 1] = '\0';
result = tzparse(&u.buf[1], &ts, FALSE);
if (result == 0 && ts.typecnt == 2 &&
sp->charcnt + ts.charcnt <= TZ_MAX_CHARS) {
for (i = 0; i < 2; ++i)
ts.ttis[i].tt_abbrind += sp->charcnt;
for (i = 0; i < ts.charcnt; ++i)
sp->chars[sp->charcnt++] = ts.chars[i];
i = 0;
while (i < ts.timecnt && ts.ats[i] <= sp->ats[sp->timecnt - 1])
++i;
while (i < ts.timecnt && sp->timecnt < TZ_MAX_TIMES) {
sp->ats[sp->timecnt] = ts.ats[i];
sp->types[sp->timecnt] = sp->typecnt + ts.types[i];
++sp->timecnt;
++i;
}
sp->ttis[sp->typecnt++] = ts.ttis[0];
sp->ttis[sp->typecnt++] = ts.ttis[1];
}
}
i = 2 * YEARSPERREPEAT;
sp->goback = sp->goahead = sp->timecnt > i;
sp->goback = sp->goback && sp->types[i] == sp->types[0] &&
differ_by_repeat(sp->ats[i], sp->ats[0]);
sp->goahead =
sp->goahead &&
sp->types[sp->timecnt - 1] == sp->types[sp->timecnt - 1 - i] &&
differ_by_repeat(sp->ats[sp->timecnt - 1],
sp->ats[sp->timecnt - 1 - i]);
return 0;
}
static const int mon_lengths[2][MONSPERYEAR] = {
{31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31},
{31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}};
static const int year_lengths[2] = {DAYSPERNYEAR, DAYSPERLYEAR};
/*
** Given a pointer into a time zone string, scan until a character that is not
** a valid character in a zone name is found. Return a pointer to that
** character.
*/
static const char *getzname(strp) register const char *strp;
{
register char c;
while ((c = *strp) != '\0' && !is_digit(c) && c != ',' && c != '-' &&
c != '+')
++strp;
return strp;
}
/*
** Given a pointer into an extended time zone string, scan until the ending
** delimiter of the zone name is located. Return a pointer to the delimiter.
**
** As with getzname above, the legal character set is actually quite
** restricted, with other characters producing undefined results.
** We don't do any checking here; checking is done later in common-case code.
*/
static const char *getqzname(register const char *strp, const int delim)
{
register int c;
while ((c = *strp) != '\0' && c != delim)
++strp;
return strp;
}
/*
** Given a pointer into a time zone string, extract a number from that string.
** Check that the number is within a specified range; if it is not, return
** NULL.
** Otherwise, return a pointer to the first character not part of the number.
*/
static const char *getnum(strp, nump, min, max) register const char *strp;
int *const nump;
const int min;
const int max;
{
register char c;
register int num;
if (strp == NULL || !is_digit(c = *strp)) return NULL;
num = 0;
do {
num = num * 10 + (c - '0');
if (num > max) return NULL; /* illegal value */
c = *++strp;
} while (is_digit(c));
if (num < min) return NULL; /* illegal value */
*nump = num;
return strp;
}
/*
** Given a pointer into a time zone string, extract a number of seconds,
** in hh[:mm[:ss]] form, from the string.
** If any error occurs, return NULL.
** Otherwise, return a pointer to the first character not part of the number
** of seconds.
*/
static const char *getsecs(strp, secsp) register const char *strp;
long *const secsp;
{
int num;
/*
** `HOURSPERDAY * DAYSPERWEEK - 1' allows quasi-Posix rules like
** "M10.4.6/26", which does not conform to Posix,
** but which specifies the equivalent of
** ``02:00 on the first Sunday on or after 23 Oct''.
*/
strp = getnum(strp, &num, 0, HOURSPERDAY * DAYSPERWEEK - 1);
if (strp == NULL) return NULL;
*secsp = num * (long)SECSPERHOUR;
if (*strp == ':') {
++strp;
strp = getnum(strp, &num, 0, MINSPERHOUR - 1);
if (strp == NULL) return NULL;
*secsp += num * SECSPERMIN;
if (*strp == ':') {
++strp;
/* `SECSPERMIN' allows for leap seconds. */
strp = getnum(strp, &num, 0, SECSPERMIN);
if (strp == NULL) return NULL;
*secsp += num;
}
}
return strp;
}
/*
** Given a pointer into a time zone string, extract an offset, in
** [+-]hh[:mm[:ss]] form, from the string.
** If any error occurs, return NULL.
** Otherwise, return a pointer to the first character not part of the time.
*/
static const char *getoffset(strp, offsetp) register const char *strp;
long *const offsetp;
{
register int neg = 0;
if (*strp == '-') {
neg = 1;
++strp;
} else if (*strp == '+')
++strp;
strp = getsecs(strp, offsetp);
if (strp == NULL) return NULL; /* illegal time */
if (neg) *offsetp = -*offsetp;
return strp;
}
/*
** Given a pointer into a time zone string, extract a rule in the form
** date[/time]. See POSIX section 8 for the format of "date" and "time".
** If a valid rule is not found, return NULL.
** Otherwise, return a pointer to the first character not part of the rule.
*/
static const char *getrule(strp, rulep) const char *strp;
register struct rule *const rulep;
{
if (*strp == 'J') {
/*
** Julian day.
*/
rulep->r_type = JULIAN_DAY;
++strp;
strp = getnum(strp, &rulep->r_day, 1, DAYSPERNYEAR);
} else if (*strp == 'M') {
/*
** Month, week, day.
*/
rulep->r_type = MONTH_NTH_DAY_OF_WEEK;
++strp;
strp = getnum(strp, &rulep->r_mon, 1, MONSPERYEAR);
if (strp == NULL) return NULL;
if (*strp++ != '.') return NULL;
strp = getnum(strp, &rulep->r_week, 1, 5);
if (strp == NULL) return NULL;
if (*strp++ != '.') return NULL;
strp = getnum(strp, &rulep->r_day, 0, DAYSPERWEEK - 1);
} else if (is_digit(*strp)) {
/*
** Day of year.
*/
rulep->r_type = DAY_OF_YEAR;
strp = getnum(strp, &rulep->r_day, 0, DAYSPERLYEAR - 1);
} else
return NULL; /* invalid format */
if (strp == NULL) return NULL;
if (*strp == '/') {
/*
** Time specified.
*/
++strp;
strp = getsecs(strp, &rulep->r_time);
} else
rulep->r_time = 2 * SECSPERHOUR; /* default = 2:00:00 */
return strp;
}
/*
** Given the Epoch-relative time of January 1, 00:00:00 UTC, in a year, the
** year, a rule, and the offset from UTC at the time that rule takes effect,
** calculate the Epoch-relative time that rule takes effect.
*/
static time_t transtime(janfirst, year, rulep, offset) const time_t janfirst;
const int year;
register const struct rule *const rulep;
const long offset;
{
register int leapyear;
register time_t value;
register int i;
int d, m1, yy0, yy1, yy2, dow;
INITIALIZE(value);
leapyear = isleap(year);
switch (rulep->r_type) {
case JULIAN_DAY:
/*
** Jn - Julian day, 1 == January 1, 60 == March 1 even in leap
** years.
** In non-leap years, or if the day number is 59 or less, just
** add SECSPERDAY times the day number-1 to the time of
** January 1, midnight, to get the day.
*/
value = janfirst + (rulep->r_day - 1) * SECSPERDAY;
if (leapyear && rulep->r_day >= 60) value += SECSPERDAY;
break;
case DAY_OF_YEAR:
/*
** n - day of year.
** Just add SECSPERDAY times the day number to the time of
** January 1, midnight, to get the day.
*/
value = janfirst + rulep->r_day * SECSPERDAY;
break;
case MONTH_NTH_DAY_OF_WEEK:
/*
** Mm.n.d - nth "dth day" of month m.
*/
value = janfirst;
for (i = 0; i < rulep->r_mon - 1; ++i)
value += mon_lengths[leapyear][i] * SECSPERDAY;
/*
** Use Zeller's Congruence to get day-of-week of first day of
** month.
*/
m1 = (rulep->r_mon + 9) % 12 + 1;
yy0 = (rulep->r_mon <= 2) ? (year - 1) : year;
yy1 = yy0 / 100;
yy2 = yy0 % 100;
dow = ((26 * m1 - 2) / 10 + 1 + yy2 + yy2 / 4 + yy1 / 4 - 2 * yy1) % 7;
if (dow < 0) dow += DAYSPERWEEK;
/*
** "dow" is the day-of-week of the first day of the month. Get
** the day-of-month (zero-origin) of the first "dow" day of the
** month.
*/
d = rulep->r_day - dow;
if (d < 0) d += DAYSPERWEEK;
for (i = 1; i < rulep->r_week; ++i) {
if (d + DAYSPERWEEK >= mon_lengths[leapyear][rulep->r_mon - 1])
break;
d += DAYSPERWEEK;
}
/*
** "d" is the day-of-month (zero-origin) of the day we want.
*/
value += d * SECSPERDAY;
break;
}
/*
** "value" is the Epoch-relative time of 00:00:00 UTC on the day in
** question. To get the Epoch-relative time of the specified local
** time on that day, add the transition time and the current offset
** from UTC.
*/
return value + rulep->r_time + offset;
}
/*
** Given a POSIX section 8-style TZ string, fill in the rule tables as
** appropriate.
*/
static int tzparse(name, sp, lastditch) const char *name;
register struct state *const sp;
const int lastditch;
{
const char *stdname;
const char *dstname;
size_t stdlen;
size_t dstlen;
long stdoffset;
long dstoffset;
register time_t *atp;
register unsigned char *typep;
register char *cp;
register int load_result;
INITIALIZE(dstname);
stdname = name;
if (lastditch) {
stdlen = strlen(name); /* length of standard zone name */
name += stdlen;
if (stdlen >= sizeof sp->chars) stdlen = (sizeof sp->chars) - 1;
stdoffset = 0;
} else {
if (*name == '<') {
name++;
stdname = name;
name = getqzname(name, '>');
if (*name != '>') return (-1);
stdlen = name - stdname;
name++;
} else {
name = getzname(name);
stdlen = name - stdname;
}
if (*name == '\0') return -1;
name = getoffset(name, &stdoffset);
if (name == NULL) return -1;
}
load_result = tzload(TZDEFRULES, sp, FALSE);
if (load_result != 0) sp->leapcnt = 0; /* so, we're off a little */
if (*name != '\0') {
if (*name == '<') {
dstname = ++name;
name = getqzname(name, '>');
if (*name != '>') return -1;
dstlen = name - dstname;
name++;
} else {
dstname = name;
name = getzname(name);
dstlen = name - dstname; /* length of DST zone name */
}
if (*name != '\0' && *name != ',' && *name != ';') {
name = getoffset(name, &dstoffset);
if (name == NULL) return -1;
} else
dstoffset = stdoffset - SECSPERHOUR;
if (*name == '\0' && load_result != 0) name = TZDEFRULESTRING;
if (*name == ',' || *name == ';') {
struct rule start;
struct rule end;
register int year;
register time_t janfirst;
time_t starttime;
time_t endtime;
++name;
if ((name = getrule(name, &start)) == NULL) return -1;
if (*name++ != ',') return -1;
if ((name = getrule(name, &end)) == NULL) return -1;
if (*name != '\0') return -1;
sp->typecnt = 2; /* standard time and DST */
/*
** Two transitions per year, from EPOCH_YEAR forward.
*/
sp->ttis[0].tt_gmtoff = -dstoffset;
sp->ttis[0].tt_isdst = 1;
sp->ttis[0].tt_abbrind = stdlen + 1;
sp->ttis[1].tt_gmtoff = -stdoffset;
sp->ttis[1].tt_isdst = 0;
sp->ttis[1].tt_abbrind = 0;
atp = sp->ats;
typep = sp->types;
janfirst = 0;
sp->timecnt = 0;
for (year = EPOCH_YEAR; sp->timecnt + 2 <= TZ_MAX_TIMES; ++year) {
time_t newfirst;
starttime = transtime(janfirst, year, &start, stdoffset);
endtime = transtime(janfirst, year, &end, dstoffset);
if (starttime > endtime) {
*atp++ = endtime;
*typep++ = 1; /* DST ends */
*atp++ = starttime;
*typep++ = 0; /* DST begins */
} else {
*atp++ = starttime;
*typep++ = 0; /* DST begins */
*atp++ = endtime;
*typep++ = 1; /* DST ends */
}
sp->timecnt += 2;
newfirst = janfirst;
newfirst += year_lengths[isleap(year)] * SECSPERDAY;
if (newfirst <= janfirst) break;
janfirst = newfirst;
}
} else {
register long theirstdoffset;
register long theirdstoffset;
register long theiroffset;
register int isdst;
register int i;
register int j;
if (*name != '\0') return -1;
/*
** Initial values of theirstdoffset and theirdstoffset.
*/
theirstdoffset = 0;
for (i = 0; i < sp->timecnt; ++i) {
j = sp->types[i];
if (!sp->ttis[j].tt_isdst) {
theirstdoffset = -sp->ttis[j].tt_gmtoff;
break;
}
}
theirdstoffset = 0;
for (i = 0; i < sp->timecnt; ++i) {
j = sp->types[i];
if (sp->ttis[j].tt_isdst) {
theirdstoffset = -sp->ttis[j].tt_gmtoff;
break;
}
}
/*
** Initially we're assumed to be in standard time.
*/
isdst = FALSE;
theiroffset = theirstdoffset;
/*
** Now juggle transition times and types
** tracking offsets as you do.
*/
for (i = 0; i < sp->timecnt; ++i) {
j = sp->types[i];
sp->types[i] = sp->ttis[j].tt_isdst;
if (sp->ttis[j].tt_ttisgmt) {
/* No adjustment to transition time */
} else {
/*
** If summer time is in effect, and the
** transition time was not specified as
** standard time, add the summer time
** offset to the transition time;
** otherwise, add the standard time
** offset to the transition time.
*/
/*
** Transitions from DST to DDST
** will effectively disappear since
** POSIX provides for only one DST
** offset.
*/
if (isdst && !sp->ttis[j].tt_ttisstd) {
sp->ats[i] += dstoffset - theirdstoffset;
} else {
sp->ats[i] += stdoffset - theirstdoffset;
}
}
theiroffset = -sp->ttis[j].tt_gmtoff;
if (sp->ttis[j].tt_isdst)
theirdstoffset = theiroffset;
else
theirstdoffset = theiroffset;
}
/*
** Finally, fill in ttis.
** ttisstd and ttisgmt need not be handled.
*/
sp->ttis[0].tt_gmtoff = -stdoffset;
sp->ttis[0].tt_isdst = FALSE;
sp->ttis[0].tt_abbrind = 0;
sp->ttis[1].tt_gmtoff = -dstoffset;
sp->ttis[1].tt_isdst = TRUE;
sp->ttis[1].tt_abbrind = stdlen + 1;
sp->typecnt = 2;
}
} else {
dstlen = 0;
sp->typecnt = 1; /* only standard time */
sp->timecnt = 0;