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bionic/libc/tzcode/localtime.c
Elliott Hughes d1c28a361b Improve libc time zone fallback behavior. 
We should fall back to GMT if neither the environment variable nor the
system property is set. This is the case if you wipe a WiFi-only device,
because we currently only take the time zone from cell networks.

Bug: http://b/24773112
Change-Id: I90d236d4d492b6562d75021bd312030b91c1e298
2015-11-13 08:38:48 -08:00

2512 lines
62 KiB
C
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/*
** This file is in the public domain, so clarified as of
** 1996-06-05 by Arthur David Olson.
*/
/*
** Leap second handling from Bradley White.
** POSIX-style TZ environment variable handling from Guy Harris.
*/
/*LINTLIBRARY*/
#define LOCALTIME_IMPLEMENTATION
#include "private.h"
#include "tzfile.h"
#include "fcntl.h"
#if THREAD_SAFE
# include <pthread.h>
static pthread_mutex_t locallock = PTHREAD_MUTEX_INITIALIZER;
static int lock(void) { return pthread_mutex_lock(&locallock); }
static void unlock(void) { pthread_mutex_unlock(&locallock); }
#else
static int lock(void) { return 0; }
static void unlock(void) { }
#endif
/* NETBSD_INSPIRED_EXTERN functions are exported to callers if
NETBSD_INSPIRED is defined, and are private otherwise. */
#if NETBSD_INSPIRED
# define NETBSD_INSPIRED_EXTERN
#else
# define NETBSD_INSPIRED_EXTERN static
#endif
#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 const 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 */
int_fast32_t tt_gmtoff; /* UT offset in seconds */
bool tt_isdst; /* used to set tm_isdst */
int tt_abbrind; /* abbreviation list index */
bool tt_ttisstd; /* transition is std time */
bool tt_ttisgmt; /* transition is UT */
};
struct lsinfo { /* leap second information */
time_t ls_trans; /* transition time */
int_fast64_t ls_corr; /* correction to apply */
};
#define SMALLEST(a, b) (((a) < (b)) ? (a) : (b))
#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;
bool goback;
bool 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];
int defaulttype; /* for early times or if no transitions */
};
enum r_type {
JULIAN_DAY, /* Jn = Julian day */
DAY_OF_YEAR, /* n = day of year */
MONTH_NTH_DAY_OF_WEEK /* Mm.n.d = month, week, day of week */
};
struct rule {
enum r_type r_type; /* type of rule */
int r_day; /* day number of rule */
int r_week; /* week number of rule */
int r_mon; /* month number of rule */
int_fast32_t r_time; /* transition time of rule */
};
static struct tm *gmtsub(struct state const *, time_t const *, int_fast32_t,
struct tm *);
static bool increment_overflow(int *, int);
static bool increment_overflow_time(time_t *, int_fast32_t);
static bool normalize_overflow32(int_fast32_t *, int *, int);
static struct tm *timesub(time_t const *, int_fast32_t, struct state const *,
struct tm *);
static bool typesequiv(struct state const *, int, int);
static bool tzparse(char const *, struct state *, bool);
#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;
char * tzname[2] = {
(char *) wildabbr,
(char *) 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
long timezone;
int daylight;
#endif /* defined USG_COMPAT */
#ifdef ALTZONE
long altzone;
#endif /* defined ALTZONE */
/* Initialize *S to a value based on GMTOFF, ISDST, and ABBRIND. */
static void
init_ttinfo(struct ttinfo *s, int_fast32_t gmtoff, bool isdst, int abbrind)
{
s->tt_gmtoff = gmtoff;
s->tt_isdst = isdst;
s->tt_abbrind = abbrind;
s->tt_ttisstd = false;
s->tt_ttisgmt = false;
}
static int_fast32_t
detzcode(const char *const codep)
{
register int_fast32_t result;
register int i;
int_fast32_t one = 1;
int_fast32_t halfmaxval = one << (32 - 2);
int_fast32_t maxval = halfmaxval - 1 + halfmaxval;
int_fast32_t minval = -1 - maxval;
result = codep[0] & 0x7f;
for (i = 1; i < 4; ++i)
result = (result << 8) | (codep[i] & 0xff);
if (codep[0] & 0x80) {
/* Do two's-complement negation even on non-two's-complement machines.
If the result would be minval - 1, return minval. */
result -= !TWOS_COMPLEMENT(int_fast32_t) && result != 0;
result += minval;
}
return result;
}
static int_fast64_t
detzcode64(const char *const codep)
{
register uint_fast64_t result;
register int i;
int_fast64_t one = 1;
int_fast64_t halfmaxval = one << (64 - 2);
int_fast64_t maxval = halfmaxval - 1 + halfmaxval;
int_fast64_t minval = -TWOS_COMPLEMENT(int_fast64_t) - maxval;
result = codep[0] & 0x7f;
for (i = 1; i < 8; ++i)
result = (result << 8) | (codep[i] & 0xff);
if (codep[0] & 0x80) {
/* Do two's-complement negation even on non-two's-complement machines.
If the result would be minval - 1, return minval. */
result -= !TWOS_COMPLEMENT(int_fast64_t) && result != 0;
result += minval;
}
return result;
}
static void
update_tzname_etc(struct state const *sp, struct ttinfo const *ttisp)
{
tzname[ttisp->tt_isdst] = (char *) &sp->chars[ttisp->tt_abbrind];
#ifdef USG_COMPAT
if (!ttisp->tt_isdst)
timezone = - ttisp->tt_gmtoff;
#endif
#ifdef ALTZONE
if (ttisp->tt_isdst)
altzone = - ttisp->tt_gmtoff;
#endif
}
static void
settzname(void)
{
register struct state * const sp = lclptr;
register int i;
tzname[0] = tzname[1] = (char *) wildabbr;
#ifdef USG_COMPAT
daylight = 0;
timezone = 0;
#endif /* defined USG_COMPAT */
#ifdef ALTZONE
altzone = 0;
#endif /* defined ALTZONE */
if (sp == NULL) {
tzname[0] = tzname[1] = (char *) gmt;
return;
}
/*
** And to get the latest zone names into tzname. . .
*/
for (i = 0; i < sp->typecnt; ++i) {
register const struct ttinfo * const ttisp = &sp->ttis[i];
update_tzname_etc(sp, ttisp);
}
for (i = 0; i < sp->timecnt; ++i) {
register const struct ttinfo * const ttisp =
&sp->ttis[
sp->types[i]];
update_tzname_etc(sp, ttisp);
#ifdef USG_COMPAT
if (ttisp->tt_isdst)
daylight = 1;
#endif /* defined USG_COMPAT */
}
}
static void
scrub_abbrs(struct state *sp)
{
int i;
/*
** 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 bool
differ_by_repeat(const time_t t1, const time_t t0)
{
if (TYPE_BIT(time_t) - TYPE_SIGNED(time_t) < SECSPERREPEAT_BITS)
return 0;
#if defined(__LP64__) // 32-bit Android/glibc has a signed 32-bit time_t; 64-bit doesn't.
return t1 - t0 == SECSPERREPEAT;
#endif
}
/* Input buffer for data read from a compiled tz file. */
union input_buffer {
/* The first part of the buffer, interpreted as a header. */
struct tzhead tzhead;
/* The entire buffer. */
char buf[2 * sizeof(struct tzhead) + 2 * sizeof (struct state)
+ 4 * TZ_MAX_TIMES];
};
/* Local storage needed for 'tzloadbody'. */
union local_storage {
/* The file name to be opened. */
char fullname[FILENAME_MAX + 1];
/* The results of analyzing the file's contents after it is opened. */
struct {
/* The input buffer. */
union input_buffer u;
/* A temporary state used for parsing a TZ string in the file. */
struct state st;
} u;
};
static int __bionic_open_tzdata(const char*);
/* Load tz data from the file named NAME into *SP. Read extended
format if DOEXTEND. Use *LSP for temporary storage. Return 0 on
success, an errno value on failure. */
static int
tzloadbody(char const *name, struct state *sp, bool doextend,
union local_storage *lsp)
{
register int i;
register int fid;
register int stored;
register ssize_t nread;
#if !defined(__ANDROID__)
register bool doaccess;
register char *fullname = lsp->fullname;
#endif
register union input_buffer *up = &lsp->u.u;
register int tzheadsize = sizeof (struct tzhead);
sp->goback = sp->goahead = false;
if (! name) {
name = TZDEFAULT;
if (! name)
return EINVAL;
}
#if defined(__ANDROID__)
fid = __bionic_open_tzdata(name);
#else
if (name[0] == ':')
++name;
doaccess = name[0] == '/';
if (!doaccess) {
char const *p = TZDIR;
if (! p)
return EINVAL;
if (sizeof lsp->fullname - 1 <= strlen(p) + strlen(name))
return ENAMETOOLONG;
strcpy(fullname, p);
strcat(fullname, "/");
strcat(fullname, name);
/* Set doaccess if '.' (as in "../") shows up in name. */
if (strchr(name, '.'))
doaccess = true;
name = fullname;
}
if (doaccess && access(name, R_OK) != 0)
return errno;
fid = open(name, OPEN_MODE);
#endif
if (fid < 0)
return errno;
nread = read(fid, up->buf, sizeof up->buf);
if (nread < tzheadsize) {
int err = nread < 0 ? errno : EINVAL;
close(fid);
return err;
}
if (close(fid) < 0)
return errno;
for (stored = 4; stored <= 8; stored *= 2) {
int_fast32_t ttisstdcnt = detzcode(up->tzhead.tzh_ttisstdcnt);
int_fast32_t ttisgmtcnt = detzcode(up->tzhead.tzh_ttisgmtcnt);
int_fast32_t leapcnt = detzcode(up->tzhead.tzh_leapcnt);
int_fast32_t timecnt = detzcode(up->tzhead.tzh_timecnt);
int_fast32_t typecnt = detzcode(up->tzhead.tzh_typecnt);
int_fast32_t charcnt = detzcode(up->tzhead.tzh_charcnt);
char const *p = up->buf + tzheadsize;
if (! (0 <= leapcnt && leapcnt < TZ_MAX_LEAPS
&& 0 < typecnt && typecnt < TZ_MAX_TYPES
&& 0 <= timecnt && timecnt < TZ_MAX_TIMES
&& 0 <= charcnt && charcnt < TZ_MAX_CHARS
&& (ttisstdcnt == typecnt || ttisstdcnt == 0)
&& (ttisgmtcnt == typecnt || ttisgmtcnt == 0)))
return EINVAL;
if (nread
< (tzheadsize /* struct tzhead */
+ timecnt * stored /* ats */
+ timecnt /* types */
+ typecnt * 6 /* ttinfos */
+ charcnt /* chars */
+ leapcnt * (stored + 4) /* lsinfos */
+ ttisstdcnt /* ttisstds */
+ ttisgmtcnt)) /* ttisgmts */
return EINVAL;
sp->leapcnt = leapcnt;
sp->timecnt = timecnt;
sp->typecnt = typecnt;
sp->charcnt = charcnt;
/* Read transitions, discarding those out of time_t range.
But pretend the last transition before time_t_min
occurred at time_t_min. */
timecnt = 0;
for (i = 0; i < sp->timecnt; ++i) {
int_fast64_t at
= stored == 4 ? detzcode(p) : detzcode64(p);
sp->types[i] = at <= time_t_max;
if (sp->types[i]) {
time_t attime
= ((TYPE_SIGNED(time_t) ? at < time_t_min : at < 0)
? time_t_min : at);
if (timecnt && attime <= sp->ats[timecnt - 1]) {
if (attime < sp->ats[timecnt - 1])
return EINVAL;
sp->types[i - 1] = 0;
timecnt--;
}
sp->ats[timecnt++] = attime;
}
p += stored;
}
timecnt = 0;
for (i = 0; i < sp->timecnt; ++i) {
unsigned char typ = *p++;
if (sp->typecnt <= typ)
return EINVAL;
if (sp->types[i])
sp->types[timecnt++] = typ;
}
sp->timecnt = timecnt;
for (i = 0; i < sp->typecnt; ++i) {
register struct ttinfo * ttisp;
unsigned char isdst, abbrind;
ttisp = &sp->ttis[i];
ttisp->tt_gmtoff = detzcode(p);
p += 4;
isdst = *p++;
if (! (isdst < 2))
return EINVAL;
ttisp->tt_isdst = isdst;
abbrind = *p++;
if (! (abbrind < sp->charcnt))
return EINVAL;
ttisp->tt_abbrind = abbrind;
}
for (i = 0; i < sp->charcnt; ++i)
sp->chars[i] = *p++;
sp->chars[i] = '\0'; /* ensure '\0' at end */
/* Read leap seconds, discarding those out of time_t range. */
leapcnt = 0;
for (i = 0; i < sp->leapcnt; ++i) {
int_fast64_t tr = stored == 4 ? detzcode(p) : detzcode64(p);
int_fast32_t corr = detzcode(p + stored);
p += stored + 4;
if (tr <= time_t_max) {
time_t trans
= ((TYPE_SIGNED(time_t) ? tr < time_t_min : tr < 0)
? time_t_min : tr);
if (leapcnt && trans <= sp->lsis[leapcnt - 1].ls_trans) {
if (trans < sp->lsis[leapcnt - 1].ls_trans)
return EINVAL;
leapcnt--;
}
sp->lsis[leapcnt].ls_trans = trans;
sp->lsis[leapcnt].ls_corr = corr;
leapcnt++;
}
}
sp->leapcnt = leapcnt;
for (i = 0; i < sp->typecnt; ++i) {
register struct ttinfo * ttisp;
ttisp = &sp->ttis[i];
if (ttisstdcnt == 0)
ttisp->tt_ttisstd = false;
else {
if (*p != true && *p != false)
return EINVAL;
ttisp->tt_ttisstd = *p++;
}
}
for (i = 0; i < sp->typecnt; ++i) {
register struct ttinfo * ttisp;
ttisp = &sp->ttis[i];
if (ttisgmtcnt == 0)
ttisp->tt_ttisgmt = false;
else {
if (*p != true && *p != false)
return EINVAL;
ttisp->tt_ttisgmt = *p++;
}
}
/*
** If this is an old file, we're done.
*/
if (up->tzhead.tzh_version[0] == '\0')
break;
nread -= p - up->buf;
memmove(up->buf, p, nread);
}
if (doextend && nread > 2 &&
up->buf[0] == '\n' && up->buf[nread - 1] == '\n' &&
sp->typecnt + 2 <= TZ_MAX_TYPES) {
struct state *ts = &lsp->u.st;
up->buf[nread - 1] = '\0';
if (tzparse(&up->buf[1], ts, false)
&& ts->typecnt == 2) {
/* Attempt to reuse existing abbreviations.
Without this, America/Anchorage would stop
working after 2037 when TZ_MAX_CHARS is 50, as
sp->charcnt equals 42 (for LMT CAT CAWT CAPT AHST
AHDT YST AKDT AKST) and ts->charcnt equals 10
(for AKST AKDT). Reusing means sp->charcnt can
stay 42 in this example. */
int gotabbr = 0;
int charcnt = sp->charcnt;
for (i = 0; i < 2; i++) {
char *tsabbr = ts->chars + ts->ttis[i].tt_abbrind;
int j;
for (j = 0; j < charcnt; j++)
if (strcmp(sp->chars + j, tsabbr) == 0) {
ts->ttis[i].tt_abbrind = j;
gotabbr++;
break;
}
if (! (j < charcnt)) {
int tsabbrlen = strlen(tsabbr);
if (j + tsabbrlen < TZ_MAX_CHARS) {
strcpy(sp->chars + j, tsabbr);
charcnt = j + tsabbrlen + 1;
ts->ttis[i].tt_abbrind = j;
gotabbr++;
}
}
}
if (gotabbr == 2) {
sp->charcnt = charcnt;
for (i = 0; i < ts->timecnt; i++)
if (sp->ats[sp->timecnt - 1] < ts->ats[i])
break;
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];
}
}
}
if (sp->timecnt > 1) {
for (i = 1; i < sp->timecnt; ++i)
if (typesequiv(sp, sp->types[i], sp->types[0]) &&
differ_by_repeat(sp->ats[i], sp->ats[0])) {
sp->goback = true;
break;
}
for (i = sp->timecnt - 2; i >= 0; --i)
if (typesequiv(sp, sp->types[sp->timecnt - 1],
sp->types[i]) &&
differ_by_repeat(sp->ats[sp->timecnt - 1],
sp->ats[i])) {
sp->goahead = true;
break;
}
}
/*
** If type 0 is is unused in transitions,
** it's the type to use for early times.
*/
for (i = 0; i < sp->timecnt; ++i)
if (sp->types[i] == 0)
break;
i = i < sp->timecnt ? -1 : 0;
/*
** Absent the above,
** if there are transition times
** and the first transition is to a daylight time
** find the standard type less than and closest to
** the type of the first transition.
*/
if (i < 0 && sp->timecnt > 0 && sp->ttis[sp->types[0]].tt_isdst) {
i = sp->types[0];
while (--i >= 0)
if (!sp->ttis[i].tt_isdst)
break;
}
/*
** If no result yet, find the first standard type.
** If there is none, punt to type zero.
*/
if (i < 0) {
i = 0;
while (sp->ttis[i].tt_isdst)
if (++i >= sp->typecnt) {
i = 0;
break;
}
}
sp->defaulttype = i;
return 0;
}
/* Load tz data from the file named NAME into *SP. Read extended
format if DOEXTEND. Return 0 on success, an errno value on failure. */
static int
tzload(char const *name, struct state *sp, bool doextend)
{
#ifdef ALL_STATE
union local_storage *lsp = malloc(sizeof *lsp);
if (!lsp)
return errno;
else {
int err = tzloadbody(name, sp, doextend, lsp);
free(lsp);
return err;
}
#else
union local_storage ls;
return tzloadbody(name, sp, doextend, &ls);
#endif
}
static bool
typesequiv(const struct state *sp, int a, int b)
{
register bool result;
if (sp == NULL ||
a < 0 || a >= sp->typecnt ||
b < 0 || b >= sp->typecnt)
result = false;
else {
register const struct ttinfo * ap = &sp->ttis[a];
register const struct ttinfo * bp = &sp->ttis[b];
result = ap->tt_gmtoff == bp->tt_gmtoff &&
ap->tt_isdst == bp->tt_isdst &&
ap->tt_ttisstd == bp->tt_ttisstd &&
ap->tt_ttisgmt == bp->tt_ttisgmt &&
strcmp(&sp->chars[ap->tt_abbrind],
&sp->chars[bp->tt_abbrind]) == 0;
}
return result;
}
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 * ATTRIBUTE_PURE
getzname(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 * ATTRIBUTE_PURE
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(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(register const char *strp, int_fast32_t *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 * (int_fast32_t) 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(register const char *strp, int_fast32_t *const offsetp)
{
register bool neg = false;
if (*strp == '-') {
neg = true;
++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(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 = getoffset(strp, &rulep->r_time);
} else rulep->r_time = 2 * SECSPERHOUR; /* default = 2:00:00 */
return strp;
}
/*
** Given a year, a rule, and the offset from UT at the time that rule takes
** effect, calculate the year-relative time that rule takes effect.
*/
static int_fast32_t ATTRIBUTE_PURE
transtime(const int year, register const struct rule *const rulep,
const int_fast32_t offset)
{
register bool leapyear;
register int_fast32_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 = (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 = rulep->r_day * SECSPERDAY;
break;
case MONTH_NTH_DAY_OF_WEEK:
/*
** Mm.n.d - nth "dth day" of month m.
*/
/*
** 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;
for (i = 0; i < rulep->r_mon - 1; ++i)
value += mon_lengths[leapyear][i] * SECSPERDAY;
break;
}
/*
** "value" is the year-relative time of 00:00:00 UT on the day in
** question. To get the year-relative time of the specified local
** time on that day, add the transition time and the current offset
** from UT.
*/
return value + rulep->r_time + offset;
}
/*
** Given a POSIX section 8-style TZ string, fill in the rule tables as
** appropriate.
*/
static bool
tzparse(const char *name, struct state *sp, bool lastditch)
{
const char * stdname;
const char * dstname;
size_t stdlen;
size_t dstlen;
size_t charcnt;
int_fast32_t stdoffset;
int_fast32_t dstoffset;
register char * cp;
register bool load_ok;
stdname = name;
if (lastditch) {
stdlen = sizeof gmt - 1;
name += stdlen;
stdoffset = 0;
} else {
if (*name == '<') {
name++;
stdname = name;
name = getqzname(name, '>');
if (*name != '>')
return false;
stdlen = name - stdname;
name++;
} else {
name = getzname(name);
stdlen = name - stdname;
}
if (!stdlen)
return false;
name = getoffset(name, &stdoffset);
if (name == NULL)
return false;
}
charcnt = stdlen + 1;
if (sizeof sp->chars < charcnt)
return false;
load_ok = tzload(TZDEFRULES, sp, false) == 0;
if (!load_ok)
sp->leapcnt = 0; /* so, we're off a little */
if (*name != '\0') {
if (*name == '<') {
dstname = ++name;
name = getqzname(name, '>');
if (*name != '>')
return false;
dstlen = name - dstname;
name++;
} else {
dstname = name;
name = getzname(name);
dstlen = name - dstname; /* length of DST zone name */
}
if (!dstlen)
return false;
charcnt += dstlen + 1;
if (sizeof sp->chars < charcnt)
return false;
if (*name != '\0' && *name != ',' && *name != ';') {
name = getoffset(name, &dstoffset);
if (name == NULL)
return false;
} else dstoffset = stdoffset - SECSPERHOUR;
if (*name == '\0' && !load_ok)
name = TZDEFRULESTRING;
if (*name == ',' || *name == ';') {
struct rule start;
struct rule end;
register int year;
register int yearlim;
register int timecnt;
time_t janfirst;
++name;
if ((name = getrule(name, &start)) == NULL)
return false;
if (*name++ != ',')
return false;
if ((name = getrule(name, &end)) == NULL)
return false;
if (*name != '\0')
return false;
sp->typecnt = 2; /* standard time and DST */
/*
** Two transitions per year, from EPOCH_YEAR forward.
*/
init_ttinfo(&sp->ttis[0], -dstoffset, true, stdlen + 1);
init_ttinfo(&sp->ttis[1], -stdoffset, false, 0);
sp->defaulttype = 0;
timecnt = 0;
janfirst = 0;
yearlim = EPOCH_YEAR + YEARSPERREPEAT;
for (year = EPOCH_YEAR; year < yearlim; year++) {
int_fast32_t
starttime = transtime(year, &start, stdoffset),
endtime = transtime(year, &end, dstoffset);
int_fast32_t
yearsecs = (year_lengths[isleap(year)]
* SECSPERDAY);
bool reversed = endtime < starttime;
if (reversed) {
int_fast32_t swap = starttime;
starttime = endtime;
endtime = swap;
}
if (reversed
|| (starttime < endtime
&& (endtime - starttime
< (yearsecs
+ (stdoffset - dstoffset))))) {
if (TZ_MAX_TIMES - 2 < timecnt)
break;
yearlim = year + YEARSPERREPEAT + 1;
sp->ats[timecnt] = janfirst;
if (increment_overflow_time
(&sp->ats[timecnt], starttime))
break;
sp->types[timecnt++] = reversed;
sp->ats[timecnt] = janfirst;
if (increment_overflow_time
(&sp->ats[timecnt], endtime))
break;
sp->types[timecnt++] = !reversed;
}
if (increment_overflow_time(&janfirst, yearsecs))
break;
}
sp->timecnt = timecnt;
if (!timecnt)
sp->typecnt = 1; /* Perpetual DST. */
} else {
register int_fast32_t theirstdoffset;
register int_fast32_t theirdstoffset;
register int_fast32_t theiroffset;
register bool isdst;
register int i;
register int j;
if (*name != '\0')
return false;
/*
** 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.
*/
init_ttinfo(&sp->ttis[0], -stdoffset, false, 0);
init_ttinfo(&sp->ttis[1], -dstoffset, true, stdlen + 1);
sp->typecnt = 2;
sp->defaulttype = 0;
}
} else {
dstlen = 0;
sp->typecnt = 1; /* only standard time */
sp->timecnt = 0;
init_ttinfo(&sp->ttis[0], -stdoffset, false, 0);
sp->defaulttype = 0;
}
sp->charcnt = charcnt;
cp = sp->chars;
memcpy(cp, stdname, stdlen);
cp += stdlen;
*cp++ = '\0';
if (dstlen != 0) {
memcpy(cp, dstname, dstlen);
*(cp + dstlen) = '\0';
}
return true;
}
static void
gmtload(struct state *const sp)
{
if (tzload(gmt, sp, true) != 0)
tzparse(gmt, sp, true);
}
/* Initialize *SP to a value appropriate for the TZ setting NAME.
Return 0 on success, an errno value on failure. */
static int
zoneinit(struct state *sp, char const *name)
{
if (name && ! name[0]) {
/*
** User wants it fast rather than right.
*/
sp->leapcnt = 0; /* so, we're off a little */
sp->timecnt = 0;
sp->typecnt = 0;
sp->charcnt = 0;
sp->goback = sp->goahead = false;
init_ttinfo(&sp->ttis[0], 0, false, 0);
strcpy(sp->chars, gmt);
sp->defaulttype = 0;
return 0;
} else {
int err = tzload(name, sp, true);
if (err != 0 && name && name[0] != ':' && tzparse(name, sp, false))
err = 0;
if (err == 0)
scrub_abbrs(sp);
return err;
}
}
static void
tzsetlcl(char const *name)
{
struct state *sp = lclptr;
int lcl = name ? strlen(name) < sizeof lcl_TZname : -1;
if (lcl < 0
? lcl_is_set < 0
: 0 < lcl_is_set && strcmp(lcl_TZname, name) == 0)
return;
#ifdef ALL_STATE
if (! sp)
lclptr = sp = malloc(sizeof *lclptr);
#endif /* defined ALL_STATE */
if (sp) {
if (zoneinit(sp, name) != 0)
zoneinit(sp, "");
if (0 < lcl)
strcpy(lcl_TZname, name);
}
settzname();
lcl_is_set = lcl;
}
#ifdef STD_INSPIRED
void
tzsetwall(void)
{
if (lock() != 0)
return;
tzsetlcl(NULL);
unlock();
}
#endif
#if defined(__ANDROID__)
#define _REALLY_INCLUDE_SYS__SYSTEM_PROPERTIES_H_
#include <sys/_system_properties.h> // For __system_property_serial.
#endif
static void
tzset_unlocked(void)
{
#if defined(__ANDROID__)
// The TZ environment variable is meant to override the system-wide setting.
const char * name = getenv("TZ");
// If that's not set, look at the "persist.sys.timezone" system property.
if (name == NULL) {
static const prop_info *pi;
if (!pi) {
pi = __system_property_find("persist.sys.timezone");
}
if (pi) {
static char buf[PROP_VALUE_MAX];
static uint32_t s = -1;
static bool ok = false;
uint32_t serial = __system_property_serial(pi);
if (serial != s) {
ok = __system_property_read(pi, 0, buf) > 0;
s = serial;
}
if (ok) {
name = buf;
}
}
}
// If that's not available (because you're running AOSP on a WiFi-only
// device, say), fall back to GMT.
if (name == NULL) name = gmt;
tzsetlcl(name);
#else
tzsetlcl(getenv("TZ"));
#endif
}
void
tzset(void)
{
if (lock() != 0)
return;
tzset_unlocked();
unlock();
}
static void
gmtcheck(void)
{
static bool gmt_is_set;
if (lock() != 0)
return;
if (! gmt_is_set) {
#ifdef ALL_STATE
gmtptr = malloc(sizeof *gmtptr);
#endif
if (gmtptr)
gmtload(gmtptr);
gmt_is_set = true;
}
unlock();
}
#if NETBSD_INSPIRED
timezone_t
tzalloc(char const *name)
{
timezone_t sp = malloc(sizeof *sp);
if (sp) {
int err = zoneinit(sp, name);
if (err != 0) {
free(sp);
errno = err;
return NULL;
}
}
return sp;
}
void
tzfree(timezone_t sp)
{
free(sp);
}
/*
** NetBSD 6.1.4 has ctime_rz, but omit it because POSIX says ctime and
** ctime_r are obsolescent and have potential security problems that
** ctime_rz would share. Callers can instead use localtime_rz + strftime.
**
** NetBSD 6.1.4 has tzgetname, but omit it because it doesn't work
** in zones with three or more time zone abbreviations.
** Callers can instead use localtime_rz + strftime.
*/
#endif
/*
** The easy way to behave "as if no library function calls" localtime
** is to not call it, so we drop its guts into "localsub", which can be
** freely called. (And no, the PANS doesn't require the above behavior,
** but it *is* desirable.)
**
** If successful and SETNAME is nonzero,
** set the applicable parts of tzname, timezone and altzone;
** however, it's OK to omit this step if the time zone is POSIX-compatible,
** since in that case tzset should have already done this step correctly.
** SETNAME's type is intfast32_t for compatibility with gmtsub,
** but it is actually a boolean and its value should be 0 or 1.
*/
/*ARGSUSED*/
static struct tm *
localsub(struct state const *sp, time_t const *timep, int_fast32_t setname,
struct tm *const tmp)
{
register const struct ttinfo * ttisp;
register int i;
register struct tm * result;
const time_t t = *timep;
if (sp == NULL) {
/* Don't bother to set tzname etc.; tzset has already done it. */
return gmtsub(gmtptr, timep, 0, tmp);
}
if ((sp->goback && t < sp->ats[0]) ||
(sp->goahead && t > sp->ats[sp->timecnt - 1])) {
time_t newt = t;
register time_t seconds;
register time_t years;
if (t < sp->ats[0])
seconds = sp->ats[0] - t;
else seconds = t - sp->ats[sp->timecnt - 1];
--seconds;
years = (seconds / SECSPERREPEAT + 1) * YEARSPERREPEAT;
seconds = years * AVGSECSPERYEAR;
if (t < sp->ats[0])
newt += seconds;
else newt -= seconds;
if (newt < sp->ats[0] ||
newt > sp->ats[sp->timecnt - 1])
return NULL; /* "cannot happen" */
result = localsub(sp, &newt, setname, tmp);
if (result) {
register int_fast64_t newy;
newy = result->tm_year;
if (t < sp->ats[0])
newy -= years;
else newy += years;
if (! (INT_MIN <= newy && newy <= INT_MAX))
return NULL;
result->tm_year = newy;
}
return result;
}
if (sp->timecnt == 0 || t < sp->ats[0]) {
i = sp->defaulttype;
} else {
register int lo = 1;
register int hi = sp->timecnt;
while (lo < hi) {
register int mid = (lo + hi) >> 1;
if (t < sp->ats[mid])
hi = mid;
else lo = mid + 1;
}
i = (int) sp->types[lo - 1];
}
ttisp = &sp->ttis[i];
/*
** To get (wrong) behavior that's compatible with System V Release 2.0
** you'd replace the statement below with
** t += ttisp->tt_gmtoff;
** timesub(&t, 0L, sp, tmp);
*/
result = timesub(&t, ttisp->tt_gmtoff, sp, tmp);
if (result) {
result->tm_isdst = ttisp->tt_isdst;
#ifdef TM_ZONE
result->TM_ZONE = (char *) &sp->chars[ttisp->tt_abbrind];
#endif /* defined TM_ZONE */
if (setname)
update_tzname_etc(sp, ttisp);
}
return result;
}
#if NETBSD_INSPIRED
struct tm *
localtime_rz(struct state *sp, time_t const *timep, struct tm *tmp)
{
return localsub(sp, timep, 0, tmp);
}
#endif
static struct tm *
localtime_tzset(time_t const *timep, struct tm *tmp, bool setname)
{
int err = lock();
if (err) {
errno = err;
return NULL;
}
if (setname || !lcl_is_set)
tzset_unlocked();
tmp = localsub(lclptr, timep, setname, tmp);
unlock();
return tmp;
}
struct tm *
localtime(const time_t *timep)
{
return localtime_tzset(timep, &tm, true);
}
struct tm *
localtime_r(const time_t *timep, struct tm *tmp)
{
return localtime_tzset(timep, tmp, false);
}
/*
** gmtsub is to gmtime as localsub is to localtime.
*/
static struct tm *
gmtsub(struct state const *sp, time_t const *timep, int_fast32_t offset,
struct tm *tmp)
{
register struct tm * result;
result = timesub(timep, offset, gmtptr, tmp);
#ifdef TM_ZONE
/*
** Could get fancy here and deliver something such as
** "UT+xxxx" or "UT-xxxx" if offset is non-zero,
** but this is no time for a treasure hunt.
*/
tmp->TM_ZONE = ((char *)
(offset ? wildabbr : gmtptr ? gmtptr->chars : gmt));
#endif /* defined TM_ZONE */
return result;
}
/*
* Re-entrant version of gmtime.
*/
struct tm *
gmtime_r(const time_t *timep, struct tm *tmp)
{
gmtcheck();
return gmtsub(gmtptr, timep, 0, tmp);
}
struct tm *
gmtime(const time_t *timep)
{
return gmtime_r(timep, &tm);
}
#ifdef STD_INSPIRED
struct tm *
offtime(const time_t *timep, long offset)
{
gmtcheck();
return gmtsub(gmtptr, timep, offset, &tm);
}
#endif /* defined STD_INSPIRED */
/*
** Return the number of leap years through the end of the given year
** where, to make the math easy, the answer for year zero is defined as zero.
*/
static int ATTRIBUTE_PURE
leaps_thru_end_of(register const int y)
{
return (y >= 0) ? (y / 4 - y / 100 + y / 400) :
-(leaps_thru_end_of(-(y + 1)) + 1);
}
static struct tm *
timesub(const time_t *timep, int_fast32_t offset,
const struct state *sp, struct tm *tmp)
{
register const struct lsinfo * lp;
register time_t tdays;
register int idays; /* unsigned would be so 2003 */
register int_fast64_t rem;
int y;
register const int * ip;
register int_fast64_t corr;
register bool hit;
register int i;
corr = 0;
hit = false;
i = (sp == NULL) ? 0 : sp->leapcnt;
while (--i >= 0) {
lp = &sp->lsis[i];
if (*timep >= lp->ls_trans) {
if (*timep == lp->ls_trans) {
hit = ((i == 0 && lp->ls_corr > 0) ||
lp->ls_corr > sp->lsis[i - 1].ls_corr);
if (hit)
while (i > 0 &&
sp->lsis[i].ls_trans ==
sp->lsis[i - 1].ls_trans + 1 &&
sp->lsis[i].ls_corr ==
sp->lsis[i - 1].ls_corr + 1) {
++hit;
--i;
}
}
corr = lp->ls_corr;
break;
}
}
y = EPOCH_YEAR;
tdays = *timep / SECSPERDAY;
rem = *timep % SECSPERDAY;
while (tdays < 0 || tdays >= year_lengths[isleap(y)]) {
int newy;
register time_t tdelta;
register int idelta;
register int leapdays;
tdelta = tdays / DAYSPERLYEAR;
if (! ((! TYPE_SIGNED(time_t) || INT_MIN <= tdelta)
&& tdelta <= INT_MAX))
goto out_of_range;
idelta = tdelta;
if (idelta == 0)
idelta = (tdays < 0) ? -1 : 1;
newy = y;
if (increment_overflow(&newy, idelta))
goto out_of_range;
leapdays = leaps_thru_end_of(newy - 1) -
leaps_thru_end_of(y - 1);
tdays -= ((time_t) newy - y) * DAYSPERNYEAR;
tdays -= leapdays;
y = newy;
}
/*
** Given the range, we can now fearlessly cast...
*/
idays = tdays;
rem += offset - corr;
while (rem < 0) {
rem += SECSPERDAY;
--idays;
}
while (rem >= SECSPERDAY) {
rem -= SECSPERDAY;
++idays;
}
while (idays < 0) {
if (increment_overflow(&y, -1))
goto out_of_range;
idays += year_lengths[isleap(y)];
}
while (idays >= year_lengths[isleap(y)]) {
idays -= year_lengths[isleap(y)];
if (increment_overflow(&y, 1))
goto out_of_range;
}
tmp->tm_year = y;
if (increment_overflow(&tmp->tm_year, -TM_YEAR_BASE))
goto out_of_range;
tmp->tm_yday = idays;
/*
** The "extra" mods below avoid overflow problems.
*/
tmp->tm_wday = EPOCH_WDAY +
((y - EPOCH_YEAR) % DAYSPERWEEK) *
(DAYSPERNYEAR % DAYSPERWEEK) +
leaps_thru_end_of(y - 1) -
leaps_thru_end_of(EPOCH_YEAR - 1) +
idays;
tmp->tm_wday %= DAYSPERWEEK;
if (tmp->tm_wday < 0)
tmp->tm_wday += DAYSPERWEEK;
tmp->tm_hour = (int) (rem / SECSPERHOUR);
rem %= SECSPERHOUR;
tmp->tm_min = (int) (rem / SECSPERMIN);
/*
** A positive leap second requires a special
** representation. This uses "... ??:59:60" et seq.
*/
tmp->tm_sec = (int) (rem % SECSPERMIN) + hit;
ip = mon_lengths[isleap(y)];
for (tmp->tm_mon = 0; idays >= ip[tmp->tm_mon]; ++(tmp->tm_mon))
idays -= ip[tmp->tm_mon];
tmp->tm_mday = (int) (idays + 1);
tmp->tm_isdst = 0;
#ifdef TM_GMTOFF
tmp->TM_GMTOFF = offset;
#endif /* defined TM_GMTOFF */
return tmp;
out_of_range:
errno = EOVERFLOW;
return NULL;
}
char *
ctime(const time_t *timep)
{
/*
** Section 4.12.3.2 of X3.159-1989 requires that
** The ctime function converts the calendar time pointed to by timer
** to local time in the form of a string. It is equivalent to
** asctime(localtime(timer))
*/
struct tm *tmp = localtime(timep);
return tmp ? asctime(tmp) : NULL;
}
char *
ctime_r(const time_t *timep, char *buf)
{
struct tm mytm;
struct tm *tmp = localtime_r(timep, &mytm);
return tmp ? asctime_r(tmp, buf) : NULL;
}
/*
** Adapted from code provided by Robert Elz, who writes:
** The "best" way to do mktime I think is based on an idea of Bob
** Kridle's (so its said...) from a long time ago.
** It does a binary search of the time_t space. Since time_t's are
** just 32 bits, its a max of 32 iterations (even at 64 bits it
** would still be very reasonable).
*/
#ifndef WRONG
#define WRONG (-1)
#endif /* !defined WRONG */
/*
** Normalize logic courtesy Paul Eggert.
*/
static bool
increment_overflow(int *ip, int j)
{
register int const i = *ip;
/*
** If i >= 0 there can only be overflow if i + j > INT_MAX
** or if j > INT_MAX - i; given i >= 0, INT_MAX - i cannot overflow.
** If i < 0 there can only be overflow if i + j < INT_MIN
** or if j < INT_MIN - i; given i < 0, INT_MIN - i cannot overflow.
*/
if ((i >= 0) ? (j > INT_MAX - i) : (j < INT_MIN - i))
return true;
*ip += j;
return false;
}
static bool
increment_overflow32(int_fast32_t *const lp, int const m)
{
register int_fast32_t const l = *lp;
if ((l >= 0) ? (m > INT_FAST32_MAX - l) : (m < INT_FAST32_MIN - l))
return true;
*lp += m;
return false;
}
static bool
increment_overflow_time(time_t *tp, int_fast32_t j)
{
/*
** This is like
** 'if (! (time_t_min <= *tp + j && *tp + j <= time_t_max)) ...',
** except that it does the right thing even if *tp + j would overflow.
*/
if (! (j < 0
? (TYPE_SIGNED(time_t) ? time_t_min - j <= *tp : -1 - j < *tp)
: *tp <= time_t_max - j))
return true;
*tp += j;
return false;
}
static bool
normalize_overflow(int *const tensptr, int *const unitsptr, const int base)
{
register int tensdelta;
tensdelta = (*unitsptr >= 0) ?
(*unitsptr / base) :
(-1 - (-1 - *unitsptr) / base);
*unitsptr -= tensdelta * base;
return increment_overflow(tensptr, tensdelta);
}
static bool
normalize_overflow32(int_fast32_t *tensptr, int *unitsptr, int base)
{
register int tensdelta;
tensdelta = (*unitsptr >= 0) ?
(*unitsptr / base) :
(-1 - (-1 - *unitsptr) / base);
*unitsptr -= tensdelta * base;
return increment_overflow32(tensptr, tensdelta);
}
static int
tmcomp(register const struct tm *const atmp,
register const struct tm *const btmp)
{
register int result;
if (atmp->tm_year != btmp->tm_year)
return atmp->tm_year < btmp->tm_year ? -1 : 1;
if ((result = (atmp->tm_mon - btmp->tm_mon)) == 0 &&
(result = (atmp->tm_mday - btmp->tm_mday)) == 0 &&
(result = (atmp->tm_hour - btmp->tm_hour)) == 0 &&
(result = (atmp->tm_min - btmp->tm_min)) == 0)
result = atmp->tm_sec - btmp->tm_sec;
return result;
}
static time_t
time2sub(struct tm *const tmp,
struct tm *(*funcp)(struct state const *, time_t const *,
int_fast32_t, struct tm *),
struct state const *sp,
const int_fast32_t offset,
bool *okayp,
bool do_norm_secs)
{
register int dir;
register int i, j;
register int saved_seconds;
register int_fast32_t li;
register time_t lo;
register time_t hi;
int_fast32_t y;
time_t newt;
time_t t;
struct tm yourtm, mytm;
*okayp = false;
yourtm = *tmp;
if (do_norm_secs) {
if (normalize_overflow(&yourtm.tm_min, &yourtm.tm_sec,
SECSPERMIN))
return WRONG;
}
if (normalize_overflow(&yourtm.tm_hour, &yourtm.tm_min, MINSPERHOUR))
return WRONG;
if (normalize_overflow(&yourtm.tm_mday, &yourtm.tm_hour, HOURSPERDAY))
return WRONG;
y = yourtm.tm_year;
if (normalize_overflow32(&y, &yourtm.tm_mon, MONSPERYEAR))
return WRONG;
/*
** Turn y into an actual year number for now.
** It is converted back to an offset from TM_YEAR_BASE later.
*/
if (increment_overflow32(&y, TM_YEAR_BASE))
return WRONG;
while (yourtm.tm_mday <= 0) {
if (increment_overflow32(&y, -1))
return WRONG;
li = y + (1 < yourtm.tm_mon);
yourtm.tm_mday += year_lengths[isleap(li)];
}
while (yourtm.tm_mday > DAYSPERLYEAR) {
li = y + (1 < yourtm.tm_mon);
yourtm.tm_mday -= year_lengths[isleap(li)];
if (increment_overflow32(&y, 1))
return WRONG;
}
for ( ; ; ) {
i = mon_lengths[isleap(y)][yourtm.tm_mon];
if (yourtm.tm_mday <= i)
break;
yourtm.tm_mday -= i;
if (++yourtm.tm_mon >= MONSPERYEAR) {
yourtm.tm_mon = 0;
if (increment_overflow32(&y, 1))
return WRONG;
}
}
if (increment_overflow32(&y, -TM_YEAR_BASE))
return WRONG;
if (! (INT_MIN <= y && y <= INT_MAX))
return WRONG;
yourtm.tm_year = y;
if (yourtm.tm_sec >= 0 && yourtm.tm_sec < SECSPERMIN)
saved_seconds = 0;
else if (y + TM_YEAR_BASE < EPOCH_YEAR) {
/*
** We can't set tm_sec to 0, because that might push the
** time below the minimum representable time.
** Set tm_sec to 59 instead.
** This assumes that the minimum representable time is
** not in the same minute that a leap second was deleted from,
** which is a safer assumption than using 58 would be.
*/
if (increment_overflow(&yourtm.tm_sec, 1 - SECSPERMIN))
return WRONG;
saved_seconds = yourtm.tm_sec;
yourtm.tm_sec = SECSPERMIN - 1;
} else {
saved_seconds = yourtm.tm_sec;
yourtm.tm_sec = 0;
}
/*
** Do a binary search (this works whatever time_t's type is).
*/
lo = time_t_min;
hi = time_t_max;
for ( ; ; ) {
t = lo / 2 + hi / 2;
if (t < lo)
t = lo;
else if (t > hi)
t = hi;
if (! funcp(sp, &t, offset, &mytm)) {
/*
** Assume that t is too extreme to be represented in
** a struct tm; arrange things so that it is less
** extreme on the next pass.
*/
dir = (t > 0) ? 1 : -1;
} else dir = tmcomp(&mytm, &yourtm);
if (dir != 0) {
if (t == lo) {
if (t == time_t_max)
return WRONG;
++t;
++lo;
} else if (t == hi) {
if (t == time_t_min)
return WRONG;
--t;
--hi;
}
if (lo > hi)
return WRONG;
if (dir > 0)
hi = t;
else lo = t;
continue;
}
#if defined TM_GMTOFF && ! UNINIT_TRAP
if (mytm.TM_GMTOFF != yourtm.TM_GMTOFF
&& (yourtm.TM_GMTOFF < 0
? (-SECSPERDAY <= yourtm.TM_GMTOFF
&& (mytm.TM_GMTOFF <=
(SMALLEST (INT_FAST32_MAX, LONG_MAX)
+ yourtm.TM_GMTOFF)))
: (yourtm.TM_GMTOFF <= SECSPERDAY
&& ((BIGGEST (INT_FAST32_MIN, LONG_MIN)
+ yourtm.TM_GMTOFF)
<= mytm.TM_GMTOFF)))) {
/* MYTM matches YOURTM except with the wrong UTC offset.
YOURTM.TM_GMTOFF is plausible, so try it instead.
It's OK if YOURTM.TM_GMTOFF contains uninitialized data,
since the guess gets checked. */
time_t altt = t;
int_fast32_t diff = mytm.TM_GMTOFF - yourtm.TM_GMTOFF;
if (!increment_overflow_time(&altt, diff)) {
struct tm alttm;
if (funcp(sp, &altt, offset, &alttm)
&& alttm.tm_isdst == mytm.tm_isdst
&& alttm.TM_GMTOFF == yourtm.TM_GMTOFF
&& tmcomp(&alttm, &yourtm) == 0) {
t = altt;
mytm = alttm;
}
}
}
#endif
if (yourtm.tm_isdst < 0 || mytm.tm_isdst == yourtm.tm_isdst)
break;
/*
** Right time, wrong type.
** Hunt for right time, right type.
** It's okay to guess wrong since the guess
** gets checked.
*/
if (sp == NULL)
return WRONG;
for (i = sp->typecnt - 1; i >= 0; --i) {
if (sp->ttis[i].tt_isdst != yourtm.tm_isdst)
continue;
for (j = sp->typecnt - 1; j >= 0; --j) {
if (sp->ttis[j].tt_isdst == yourtm.tm_isdst)
continue;
newt = t + sp->ttis[j].tt_gmtoff -
sp->ttis[i].tt_gmtoff;
if (! funcp(sp, &newt, offset, &mytm))
continue;
if (tmcomp(&mytm, &yourtm) != 0)
continue;
if (mytm.tm_isdst != yourtm.tm_isdst)
continue;
/*
** We have a match.
*/
t = newt;
goto label;
}
}
return WRONG;
}
label:
newt = t + saved_seconds;
if ((newt < t) != (saved_seconds < 0))
return WRONG;
t = newt;
if (funcp(sp, &t, offset, tmp))
*okayp = true;
return t;
}
static time_t
time2(struct tm * const tmp,
struct tm *(*funcp)(struct state const *, time_t const *,
int_fast32_t, struct tm *),
struct state const *sp,
const int_fast32_t offset,
bool *okayp)
{
time_t t;
/*
** First try without normalization of seconds
** (in case tm_sec contains a value associated with a leap second).
** If that fails, try with normalization of seconds.
*/
t = time2sub(tmp, funcp, sp, offset, okayp, false);
return *okayp ? t : time2sub(tmp, funcp, sp, offset, okayp, true);
}
static time_t
time1(struct tm *const tmp,
struct tm *(*funcp) (struct state const *, time_t const *,
int_fast32_t, struct tm *),
struct state const *sp,
const int_fast32_t offset)
{
register time_t t;
register int samei, otheri;
register int sameind, otherind;
register int i;
register int nseen;
char seen[TZ_MAX_TYPES];
unsigned char types[TZ_MAX_TYPES];
bool okay;
if (tmp == NULL) {
errno = EINVAL;
return WRONG;
}
if (tmp->tm_isdst > 1)
tmp->tm_isdst = 1;
t = time2(tmp, funcp, sp, offset, &okay);
if (okay)
return t;
if (tmp->tm_isdst < 0)
#ifdef PCTS
/*
** POSIX Conformance Test Suite code courtesy Grant Sullivan.
*/
tmp->tm_isdst = 0; /* reset to std and try again */
#else
return t;
#endif /* !defined PCTS */
/*
** We're supposed to assume that somebody took a time of one type
** and did some math on it that yielded a "struct tm" that's bad.
** We try to divine the type they started from and adjust to the
** type they need.
*/
if (sp == NULL)
return WRONG;
for (i = 0; i < sp->typecnt; ++i)
seen[i] = false;
nseen = 0;
for (i = sp->timecnt - 1; i >= 0; --i)
if (!seen[sp->types[i]]) {
seen[sp->types[i]] = true;
types[nseen++] = sp->types[i];
}
for (sameind = 0; sameind < nseen; ++sameind) {
samei = types[sameind];
if (sp->ttis[samei].tt_isdst != tmp->tm_isdst)
continue;
for (otherind = 0; otherind < nseen; ++otherind) {
otheri = types[otherind];
if (sp->ttis[otheri].tt_isdst == tmp->tm_isdst)
continue;
tmp->tm_sec += sp->ttis[otheri].tt_gmtoff -
sp->ttis[samei].tt_gmtoff;
tmp->tm_isdst = !tmp->tm_isdst;
t = time2(tmp, funcp, sp, offset, &okay);
if (okay)
return t;
tmp->tm_sec -= sp->ttis[otheri].tt_gmtoff -
sp->ttis[samei].tt_gmtoff;
tmp->tm_isdst = !tmp->tm_isdst;
}
}
return WRONG;
}
static time_t
mktime_tzname(struct state *sp, struct tm *tmp, bool setname)
{
if (sp)
return time1(tmp, localsub, sp, setname);
else {
gmtcheck();
return time1(tmp, gmtsub, gmtptr, 0);
}
}
#if NETBSD_INSPIRED
time_t
mktime_z(struct state *sp, struct tm *tmp)
{
return mktime_tzname(sp, tmp, false);
}
#endif
time_t
mktime(struct tm *tmp)
{
time_t t;
int err = lock();
if (err) {
errno = err;
return -1;
}
tzset_unlocked();
t = mktime_tzname(lclptr, tmp, true);
unlock();
return t;
}
#ifdef STD_INSPIRED
time_t
timelocal(struct tm *tmp)
{
if (tmp != NULL)
tmp->tm_isdst = -1; /* in case it wasn't initialized */
return mktime(tmp);
}
time_t
timegm(struct tm *tmp)
{
return timeoff(tmp, 0);
}
time_t
timeoff(struct tm *tmp, long offset)
{
if (tmp)
tmp->tm_isdst = 0;
gmtcheck();
return time1(tmp, gmtsub, gmtptr, offset);
}
#endif /* defined STD_INSPIRED */
/*
** XXX--is the below the right way to conditionalize??
*/
#ifdef STD_INSPIRED
/*
** IEEE Std 1003.1-1988 (POSIX) legislates that 536457599
** shall correspond to "Wed Dec 31 23:59:59 UTC 1986", which
** is not the case if we are accounting for leap seconds.
** So, we provide the following conversion routines for use
** when exchanging timestamps with POSIX conforming systems.
*/
static int_fast64_t
leapcorr(struct state const *sp, time_t t)
{
register struct lsinfo const * lp;
register int i;
i = sp->leapcnt;
while (--i >= 0) {
lp = &sp->lsis[i];
if (t >= lp->ls_trans)
return lp->ls_corr;
}
return 0;
}
NETBSD_INSPIRED_EXTERN time_t ATTRIBUTE_PURE
time2posix_z(struct state *sp, time_t t)
{
return t - leapcorr(sp, t);
}
time_t
time2posix(time_t t)
{
int err = lock();
if (err) {
errno = err;
return -1;
}
if (!lcl_is_set)
tzset_unlocked();
if (lclptr)
t = time2posix_z(lclptr, t);
unlock();
return t;
}
NETBSD_INSPIRED_EXTERN time_t ATTRIBUTE_PURE
posix2time_z(struct state *sp, time_t t)
{
time_t x;
time_t y;
/*
** For a positive leap second hit, the result
** is not unique. For a negative leap second
** hit, the corresponding time doesn't exist,
** so we return an adjacent second.
*/
x = t + leapcorr(sp, t);
y = x - leapcorr(sp, x);
if (y < t) {
do {
x++;
y = x - leapcorr(sp, x);
} while (y < t);
x -= y != t;
} else if (y > t) {
do {
--x;
y = x - leapcorr(sp, x);
} while (y > t);
x += y != t;
}
return x;
}
time_t
posix2time(time_t t)
{
int err = lock();
if (err) {
errno = err;
return -1;
}
if (!lcl_is_set)
tzset_unlocked();
if (lclptr)
t = posix2time_z(lclptr, t);
unlock();
return t;
}
#endif /* defined STD_INSPIRED */
#ifdef time_tz
/* Convert from the underlying system's time_t to the ersatz time_tz,
which is called 'time_t' in this file. */
time_t
time(time_t *p)
{
time_t r = sys_time(0);
if (p)
*p = r;
return r;
}
#endif
// BEGIN android-added
#include <assert.h>
#include <stdint.h>
#include <arpa/inet.h> // For ntohl(3).
static int __bionic_open_tzdata_path(const char* path_prefix_variable, const char* path_suffix,
const char* olson_id) {
const char* path_prefix = getenv(path_prefix_variable);
if (path_prefix == NULL) {
fprintf(stderr, "%s: %s not set!\n", __FUNCTION__, path_prefix_variable);
return -1;
}
size_t path_length = strlen(path_prefix) + 1 + strlen(path_suffix) + 1;
char* path = malloc(path_length);
if (path == NULL) {
fprintf(stderr, "%s: couldn't allocate %zu-byte path\n", __FUNCTION__, path_length);
return -1;
}
snprintf(path, path_length, "%s/%s", path_prefix, path_suffix);
int fd = TEMP_FAILURE_RETRY(open(path, OPEN_MODE));
if (fd == -1) {
free(path);
return -2; // Distinguish failure to find any data from failure to find a specific id.
}
// byte[12] tzdata_version -- "tzdata2012f\0"
// int index_offset
// int data_offset
// int zonetab_offset
struct bionic_tzdata_header {
char tzdata_version[12];
int32_t index_offset;
int32_t data_offset;
int32_t zonetab_offset;
} header;
memset(&header, 0, sizeof(header));
ssize_t bytes_read = TEMP_FAILURE_RETRY(read(fd, &header, sizeof(header)));
if (bytes_read != sizeof(header)) {
fprintf(stderr, "%s: could not read header of \"%s\": %s\n",
__FUNCTION__, path, (bytes_read == -1) ? strerror(errno) : "short read");
free(path);
close(fd);
return -1;
}
if (strncmp(header.tzdata_version, "tzdata", 6) != 0 || header.tzdata_version[11] != 0) {
fprintf(stderr, "%s: bad magic in \"%s\": \"%.6s\"\n",
__FUNCTION__, path, header.tzdata_version);
free(path);
close(fd);
return -1;
}
#if 0
fprintf(stderr, "version: %s\n", header.tzdata_version);
fprintf(stderr, "index_offset = %d\n", ntohl(header.index_offset));
fprintf(stderr, "data_offset = %d\n", ntohl(header.data_offset));
fprintf(stderr, "zonetab_offset = %d\n", ntohl(header.zonetab_offset));
#endif
if (TEMP_FAILURE_RETRY(lseek(fd, ntohl(header.index_offset), SEEK_SET)) == -1) {
fprintf(stderr, "%s: couldn't seek to index in \"%s\": %s\n",
__FUNCTION__, path, strerror(errno));
free(path);
close(fd);
return -1;
}
off_t specific_zone_offset = -1;
ssize_t index_size = ntohl(header.data_offset) - ntohl(header.index_offset);
char* index = malloc(index_size);
if (index == NULL) {
fprintf(stderr, "%s: couldn't allocate %zd-byte index for \"%s\"\n",
__FUNCTION__, index_size, path);
free(path);
close(fd);
return -1;
}
if (TEMP_FAILURE_RETRY(read(fd, index, index_size)) != index_size) {
fprintf(stderr, "%s: could not read index of \"%s\": %s\n",
__FUNCTION__, path, (bytes_read == -1) ? strerror(errno) : "short read");
free(path);
free(index);
close(fd);
return -1;
}
static const size_t NAME_LENGTH = 40;
struct index_entry_t {
char buf[NAME_LENGTH];
int32_t start;
int32_t length;
int32_t unused; // Was raw GMT offset; always 0 since tzdata2014f (L).
};
size_t id_count = (ntohl(header.data_offset) - ntohl(header.index_offset)) / sizeof(struct index_entry_t);
struct index_entry_t* entry = (struct index_entry_t*) index;
for (size_t i = 0; i < id_count; ++i) {
char this_id[NAME_LENGTH + 1];
memcpy(this_id, entry->buf, NAME_LENGTH);
this_id[NAME_LENGTH] = '\0';
if (strcmp(this_id, olson_id) == 0) {
specific_zone_offset = ntohl(entry->start) + ntohl(header.data_offset);
break;
}
++entry;
}
free(index);
if (specific_zone_offset == -1) {
free(path);
close(fd);
return -1;
}
if (TEMP_FAILURE_RETRY(lseek(fd, specific_zone_offset, SEEK_SET)) == -1) {
fprintf(stderr, "%s: could not seek to %ld in \"%s\": %s\n",
__FUNCTION__, specific_zone_offset, path, strerror(errno));
free(path);
close(fd);
return -1;
}
// TODO: check that there's TZ_MAGIC at this offset, so we can fall back to the other file if not.
free(path);
return fd;
}
static int __bionic_open_tzdata(const char* olson_id) {
int fd = __bionic_open_tzdata_path("ANDROID_DATA", "/misc/zoneinfo/current/tzdata", olson_id);
if (fd < 0) {
fd = __bionic_open_tzdata_path("ANDROID_ROOT", "/usr/share/zoneinfo/tzdata", olson_id);
if (fd == -2) {
// The first thing that 'recovery' does is try to format the current time. It doesn't have
// any tzdata available, so we must not abort here --- doing so breaks the recovery image!
fprintf(stderr, "%s: couldn't find any tzdata when looking for %s!\n", __FUNCTION__, olson_id);
}
}
return fd;
}
// Caches the most recent timezone (http://b/8270865).
static int __bionic_tzload_cached(const char* name, struct state* const sp, const int doextend) {
lock();
// Our single-item cache.
static char* g_cached_time_zone_name;
static struct state g_cached_time_zone;
// Do we already have this timezone cached?
if (g_cached_time_zone_name != NULL && strcmp(name, g_cached_time_zone_name) == 0) {
*sp = g_cached_time_zone;
unlock();
return 0;
}
// Can we load it?
int rc = tzload(name, sp, doextend);
if (rc == 0) {
// Update the cache.
free(g_cached_time_zone_name);
g_cached_time_zone_name = strdup(name);
g_cached_time_zone = *sp;
}
unlock();
return rc;
}
// Non-standard API: mktime(3) but with an explicit timezone parameter.
// This can't actually be hidden/removed until we fix MtpUtils.cpp
__attribute__((visibility("default"))) time_t mktime_tz(struct tm* const tmp, const char* tz) {
struct state* st = malloc(sizeof(*st));
time_t return_value;
if (st == NULL)
return 0;
if (__bionic_tzload_cached(tz, st, true) != 0) {
// TODO: not sure what's best here, but for now, we fall back to gmt.
gmtload(st);
}
return_value = time1(tmp, localsub, st, 0L);
free(st);
return return_value;
}
// END android-added
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