Mirrors_Framework/nuttx
1
0
Fork 0
mirror of https://github.com/apache/nuttx.git synced 2026-05-19 03:03:37 +08:00
Code Issues Actions 1 Packages Projects Releases Wiki Activity
Files
4b4ba522cb7ffecdcea1d78bc7e830f65135cb4f
nuttx/libs/libc/time/lib_localtime.c
T
Huang Qi e09048cc88 style: Fix "is is" typo across the codebase. 
Correct duplicate "is is" word found in 181 files throughout the
codebase.
In most cases "is is" was changed to "is", but in contexts like
"MCU is is sleep mode" it was corrected to "MCU in sleep mode".

Also fixes a "the the" typo in net/inet/inet_sockif.c.

This is a pure style/documentation fix that improves code readability.

Signed-off-by: Huang Qi <huangqi3@xiaomi.com>
2026-03-24 09:39:26 +08:00

2858 lines
73 KiB
C
Raw Blame History

/****************************************************************************
* libs/libc/time/lib_localtime.c
*
* SPDX-License-Identifier: BSD-3-Clause
* SPDX-FileCopyrightText: 2014 Gregory Nutt. All rights reserved.
* SPDX-FileContributor: Ported to NuttX by Max Neklyudov
* SPDX-FileContributor: Guy Harris
* SPDX-FileContributor: Bradley White
* SPDX-FileContributor: Arthur David Olson
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>
#include <fcntl.h>
#include <assert.h>
#include <errno.h>
#include <sys/param.h>
#include <nuttx/irq.h>
#include <nuttx/clock.h>
#include <nuttx/init.h>
#include <nuttx/fs/fs.h>
#include <nuttx/mutex.h>
#include "libc.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Configuration ************************************************************/
/* Time zone object file directory */
#ifdef CONFIG_LIBC_TZDIR
# define TZDIR CONFIG_LIBC_TZDIR
#else
# define TZDIR "/etc/zoneinfo"
#endif
/* Time definitions *********************************************************/
/* Time zone files */
#define TZ_MAGIC "TZif"
#define TZDEFAULT "localtime"
#define TZDEFRULES "posixrules"
/* In the current implementation, "tzset()" refuses to deal with files that
* exceed any of the limits below.
*/
#define TZ_MAX_CHARS 50 /* Maximum number of abbreviation characters */
#define TZ_MAX_LEAPS 50 /* Maximum number of leap second corrections */
#define SECSPERHOUR (SECSPERMIN * MINSPERHOUR)
#define SECSPERDAY ((int_fast32_t)SECSPERHOUR * HOURSPERDAY)
#define isleap(y) (((y) % 4) == 0 && (((y) % 100) != 0 || ((y) % 400) == 0))
#define GRANDPARENTED "Local time zone must be set--see zic manual page"
#define TYPE_BIT(type) (sizeof(type) * CHAR_BIT)
#define TYPE_SIGNED(type) (((type)-1) < 0)
#define TWOS_COMPLEMENT(t) ((t) ~ (t) 0 < 0)
#define YEARSPERREPEAT 400 /* years before a Gregorian repeat */
#define DAYSPERREPEAT ((int_fast32_t) 400 * 365 + 100 - 4 + 1)
/* The Gregorian year averages 365.2425 days, which is 31556952 seconds. */
#define AVGSECSPERYEAR 31556952L
#define SECSPERREPEAT ((int_fast64_t)YEARSPERREPEAT * (int_fast64_t)AVGSECSPERYEAR)
#define TZ_ABBR_MAX_LEN 16
#define TZ_ABBR_CHAR_SET \
"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789 :+-._"
#define TZ_ABBR_ERR_CHAR '_'
/* Unlike <ctype.h>'s isdigit, this also works if c < 0 | c > UCHAR_MAX. */
#define is_digit(c) ((unsigned)(c) - '0' <= 9)
#define MY_TZNAME_MAX 255
/* Max and min values of the integer type T, of which only the bottom
* B bits are used, and where the highest-order used bit is considered
* to be a sign bit if T is signed.
*/
#define MAXVAL(t, b) \
((t) (((t) 1 << ((b) - 1 - TYPE_SIGNED(t))) - \
1 + ((t) 1 << ((b) - 1 - TYPE_SIGNED(t)))))
#define MINVAL(t, b) \
((t) (TYPE_SIGNED(t) ? - TWOS_COMPLEMENT(t) - MAXVAL(t, b) : 0))
/* The extreme time values, assuming no padding. */
#define TIME_T_MIN MINVAL(time_t, TYPE_BIT(time_t))
#define TIME_T_MAX MAXVAL(time_t, TYPE_BIT(time_t))
/* This abbreviation means local time is unspecified. */
#define UNSPEC "-00"
/* How many extra bytes are needed at the end of struct state's chars array.
* This needs to be at least 1 for null termination in case the input
* data isn't properly terminated, and it also needs to be big enough
* for ttunspecified to work without crashing.
*/
#define CHARS_EXTRA (MAX(sizeof(UNSPEC), 2) - 1)
#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 */
/* 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.
*
* 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 " "
/* The DST rules to use if TZ has no rules and we can't load TZDEFRULES.
* We default to US rules as of 2017-05-07.
* 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.
*/
#define TZDEFRULESTRING ",M3.2.0,M11.1.0"
/****************************************************************************
* Private Types
****************************************************************************/
/* Time file file header.
* Each time zone file begins with a time zone header followed by:
*
* tzh_timecnt (char [4])s coded transition times a la time(2)
* tzh_timecnt (unsigned char)s types of local time starting at above
* tzh_typecnt repetitions of
* one (char [4]) coded UT offset in seconds
* one (unsigned char) used to set tm_isdst
* one (unsigned char) that's an abbreviation list index
* tzh_charcnt (char)s '\0'-terminated zone abbreviations
* tzh_leapcnt repetitions of
* one (char [4]) coded leap second transition times
* one (char [4]) total correction after above
* tzh_ttisstdcnt (char)s indexed by type; if TRUE, transition
* time is standard time, if FALSE,
* transition time is wall clock time
* if absent, transition times are
* assumed to be wall clock time
* tzh_ttisutcnt (char)s indexed by type; if TRUE, transition
* time is UT, if FALSE,
* transition time is local time
* if absent, transition times are
* assumed to be local time
*
* If tzh_version is '2' or greater, the above is followed by a second
* instance of tzhead_s and a second instance of the data in which each
* coded transition time uses 8 rather than 4 chars, then a
* POSIX-TZ-environment-variable-style string for use in handling instants
* after the last transition time stored in the file (with nothing between
* the newlines if there is no POSIX representation for such instants).
*
* If tz_version is '3' or greater, the above is extended as follows.
* First, the POSIX TZ string's hour offset may range from -167 through
* 167 as compared to the POSIX-required 0 through 24. Second, its DST
* start time may be January 1 at 00:00 and its stop time December 31 at
* 24:00 plus the difference between DST and standard time, indicating DST
* all year.
*/
struct tzhead_s
{
char tzh_magic[4]; /* TZ_MAGIC */
char tzh_version[1]; /* '\0' or '2' or '3' as of 2013 */
char tzh_reserved[15]; /* reserved; must be zero */
char tzh_ttisutcnt[4]; /* coded number of trans. time flags */
char tzh_ttisstdcnt[4]; /* coded number of trans. time flags */
char tzh_leapcnt[4]; /* coded number of leap seconds */
char tzh_timecnt[4]; /* coded number of transition times */
char tzh_typecnt[4]; /* coded number of local time types */
char tzh_charcnt[4]; /* coded number of abbr. chars */
};
struct ttinfo_s
{ /* Time type information */
int_fast32_t tt_utoff; /* UT offset in seconds */
int tt_isdst; /* Used to set tm_isdst */
int tt_desigidx; /* Abbreviation list index */
int tt_ttisstd; /* True if transition is std time */
int tt_ttisut; /* True if transition is UT */
};
struct lsinfo_s
{ /* Leap second information */
time_t ls_trans; /* Transition time */
int_fast32_t ls_corr; /* Correction to apply */
};
struct state_s
{
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_s ttis[TZ_MAX_TYPES];
char chars[MAX(MAX(TZ_MAX_CHARS + CHARS_EXTRA, sizeof("UTC")),
(2 * (MY_TZNAME_MAX + 1)))];
struct lsinfo_s lsis[TZ_MAX_LEAPS];
/* The time type to use for early times or if no transitions.
* It is always zero for recent tzdb releases.
* It might be nonzero for data from tzdb 2018e or earlier.
*/
int defaulttype;
};
struct rule_s
{
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 */
int_fast32_t r_time; /* transition time of rule */
};
/****************************************************************************
* Private Data
****************************************************************************/
static const char g_wildabbr[] = WILDABBR;
static const char g_etc_utc[] = "Etc/UTC";
static FAR const char *g_utc = g_etc_utc + sizeof("Etc/") - 1;
static char g_lcl_tzname[MY_TZNAME_MAX + 1];
static int g_lcl_isset;
static int g_gmt_isset;
static FAR struct state_s *g_lcl_ptr;
static FAR struct state_s *g_gmt_ptr;
static rmutex_t g_lcl_lock = NXRMUTEX_INITIALIZER;
static rmutex_t g_gmt_lock = NXRMUTEX_INITIALIZER;
/* 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 g_tm;
static const int g_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 g_year_lengths[2] =
{
DAYSPERNYEAR, DAYSPERLYEAR
};
/****************************************************************************
* Public Data
****************************************************************************/
/* Setup by tzset() */
FAR char *tzname[2] =
{
(FAR char *)g_wildabbr,
(FAR char *)g_wildabbr
};
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
static int_fast32_t detzcode(FAR const char *codep);
static int_fast64_t detzcode64(FAR const char *codep);
static FAR const char *getzname(FAR const char *strp);
static FAR const char *getqzname(FAR const char *strp, int delim);
static FAR const char *getnum(FAR const char *strp, FAR int *nump,
int min, int max);
static FAR const char *getsecs(FAR const char *strp,
FAR int_fast32_t *secsp);
static FAR const char *getoffset(FAR const char *strp,
FAR int_fast32_t *poffset);
static FAR const char *getrule(FAR const char *strp,
FAR struct rule_s *rulep);
static void gmtload(FAR struct state_s *sp);
static FAR struct tm *gmtsub(FAR const time_t *timep, int_fast32_t offset,
FAR struct tm *tmp);
static FAR struct tm *localsub(FAR const time_t *timep, int_fast32_t offset,
FAR struct tm *tmp);
static int increment_overflow(FAR int *number, int delta);
static time_t leaps_thru_end_of(time_t y);
static int increment_overflow32(FAR int_fast32_t *number, int delta);
static int increment_overflow_time(FAR time_t *t, int_fast32_t delta);
static int normalize_overflow32(FAR int_fast32_t *tensptr,
FAR int *unitsptr, int base);
static int normalize_overflow(FAR int *tensptr, FAR int *unitsptr,
int base);
static void settzname(void);
static time_t time1(FAR struct tm *tmp,
FAR struct tm *(*funcp)(FAR const time_t *, int_fast32_t,
FAR struct tm *),
int_fast32_t offset);
static time_t time2(FAR struct tm *tmp,
FAR struct tm *(*funcp)(FAR const time_t *,
int_fast32_t, FAR struct tm *),
int_fast32_t offset, FAR int *okayp);
static time_t time2sub(FAR struct tm *tmp,
FAR struct tm *(*funcp)(FAR const time_t *,
int_fast32_t, FAR struct tm *),
int_fast32_t offset, FAR int *okayp, int do_norm_secs);
static FAR struct tm *timesub(FAR const time_t *timep, int_fast32_t offset,
FAR const struct state_s *sp, FAR struct tm *tmp);
static int tmcomp(FAR const struct tm *atmp, FAR const struct tm *btmp);
static int_fast32_t transtime(int year, FAR const struct rule_s *rulep,
int_fast32_t offset);
static int typesequiv(FAR const struct state_s *sp, int a, int b);
static int tzload(FAR const char *name, FAR struct state_s *sp,
int doextend);
static int tzparse(FAR const char *name, FAR struct state_s *sp,
FAR struct state_s *basep);
/****************************************************************************
* Private Functions
****************************************************************************/
static inline void tz_lock(FAR rmutex_t *lock)
{
#if defined(__KERNEL__) || defined(CONFIG_BUILD_FLAT)
if (up_interrupt_context() || (sched_idletask() && OSINIT_IDLELOOP()))
{
return;
}
#endif
nxrmutex_lock(lock);
}
static inline void tz_unlock(FAR rmutex_t *lock)
{
#if defined(__KERNEL__) || defined(CONFIG_BUILD_FLAT)
if (up_interrupt_context() || (sched_idletask() && OSINIT_IDLELOOP()))
{
return;
}
#endif
nxrmutex_unlock(lock);
}
/* Initialize *S to a value based on UTOFF, ISDST, and DESIGIDX. */
static void init_ttinfo(FAR struct ttinfo_s *s, int_fast32_t utoff,
bool isdst, int desigidx)
{
s->tt_utoff = utoff;
s->tt_isdst = isdst;
s->tt_desigidx = desigidx;
s->tt_ttisstd = false;
s->tt_ttisut = false;
}
/* Return true if SP's time type I does not specify local time. */
static int ttunspecified(FAR const struct state_s *sp, int i)
{
FAR char const *abbr = &sp->chars[sp->ttis[i].tt_desigidx];
/* memcmp is likely faster than strcmp, and is safe due to CHARS_EXTRA. */
return memcmp(abbr, UNSPEC, sizeof(UNSPEC)) == 0;
}
static int_fast32_t detzcode(FAR const char *codep)
{
int_fast32_t result;
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;
int i;
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(FAR const char *codep)
{
int_fast64_t result;
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;
int i;
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 scrub_abbrs(struct state_s *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)
{
FAR const struct ttinfo_s * const ttisp = &sp->ttis[i];
FAR char *cp = &sp->chars[ttisp->tt_desigidx];
if (strlen(cp) > TZ_ABBR_MAX_LEN && strcmp(cp, GRANDPARENTED) != 0)
{
*(cp + TZ_ABBR_MAX_LEN) = '\0';
}
}
}
static void settzname(void)
{
FAR struct state_s * const sp = g_lcl_ptr;
int i;
tzname[0] = tzname[1] = (FAR char *)g_wildabbr;
if (sp == NULL)
{
tzname[0] = tzname[1] = (FAR char *)g_utc;
return;
}
/* And to get the latest zone names into tzname */
for (i = 0; i < sp->typecnt; ++i)
{
FAR const struct ttinfo_s * const ttisp = &sp->ttis[i];
tzname[ttisp->tt_isdst] = &sp->chars[ttisp->tt_desigidx];
}
for (i = 0; i < sp->timecnt; ++i)
{
FAR const struct ttinfo_s * const ttisp = &sp->ttis[sp->types[i]];
tzname[ttisp->tt_isdst] = &sp->chars[ttisp->tt_desigidx];
}
}
static int_fast32_t leapcorr(FAR const struct state_s *sp, time_t t)
{
FAR const struct lsinfo_s *lp;
int i;
i = sp->leapcnt;
while (--i >= 0)
{
lp = &sp->lsis[i];
if (t >= lp->ls_trans)
{
return lp->ls_corr;
}
}
return 0;
}
static int tzload(FAR const char *name,
FAR struct state_s *sp, int doextend)
{
int i;
int fid;
int stored;
ssize_t nread;
typedef union
{
struct tzhead_s tzhead;
char buf[2 * sizeof(struct tzhead_s) +
2 * sizeof(struct state_s) +
4 * TZ_MAX_TIMES];
} u_t;
/* 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."
*/
union local_storage
{
char fullname[FILENAME_MAX + 1];
/* The main part of the storage for this function. */
struct
{
u_t u;
struct state_s st;
} u;
};
FAR char *fullname;
FAR u_t *up;
int doaccess;
FAR union local_storage *lsp;
int tzheadsize = sizeof(struct tzhead_s);
lsp = lib_malloc(sizeof(*lsp));
if (lsp == NULL)
{
return -1;
}
fullname = lsp->fullname;
up = &lsp->u.u;
sp->goback = sp->goahead = FALSE;
if (name == NULL)
{
name = TZDEFAULT;
if (name == NULL)
{
goto oops;
}
}
if (name[0] == ':')
{
++name;
}
doaccess = name[0] == '/';
if (!doaccess)
{
FAR const char *dot;
size_t namelen = strlen(name);
const char tzdirslash[sizeof(TZDIR)] = TZDIR "/";
if (sizeof(lsp->fullname) - sizeof(tzdirslash) <= namelen)
{
goto oops;
}
/* Create a string "TZDIR/NAME". Using sprintf here
* would pull in stdio (and would fail if the
* resulting string length exceeded INT_MAX!).
*/
memcpy(fullname, tzdirslash, sizeof(tzdirslash));
strlcpy(fullname + sizeof(tzdirslash), name,
sizeof(lsp->fullname) - sizeof(tzdirslash));
/* Set doaccess if NAME contains a ".." file name
* component, as such a name could read a file outside
* the TZDIR virtual subtree.
*/
for (dot = name; (dot = strchr(dot, '.')); dot++)
{
if ((dot == name || dot[0 - 1] == '/') && dot[1] == '.' &&
(dot[2] == '/' || !dot[2]))
{
doaccess = TRUE;
break;
}
}
name = fullname;
}
if (doaccess && access(name, R_OK) != 0)
{
goto oops;
}
fid = _NX_OPEN(name, O_RDONLY | O_CLOEXEC);
if (fid < 0)
{
goto oops;
}
nread = _NX_READ(fid, up->buf, sizeof(up->buf));
if (_NX_CLOSE(fid) < 0 || nread < tzheadsize)
{
goto oops;
}
for (stored = 4; stored <= 8; stored *= 2)
{
char version = up->tzhead.tzh_version[0];
int skip_datablock = stored == 4 && version;
int_fast32_t datablock_size;
int_fast32_t ttisstdcnt;
int_fast32_t ttisutcnt;
int_fast32_t leapcnt;
int_fast32_t timecnt;
int_fast32_t typecnt;
int_fast32_t charcnt;
int_fast64_t prevtr = -1;
int_fast32_t prevcorr;
FAR const char *p;
ttisstdcnt = detzcode(up->tzhead.tzh_ttisstdcnt);
ttisutcnt = detzcode(up->tzhead.tzh_ttisutcnt);
leapcnt = detzcode(up->tzhead.tzh_leapcnt);
timecnt = detzcode(up->tzhead.tzh_timecnt);
typecnt = detzcode(up->tzhead.tzh_typecnt);
charcnt = detzcode(up->tzhead.tzh_charcnt);
p = up->buf + tzheadsize;
if (leapcnt < 0 || leapcnt > TZ_MAX_LEAPS ||
typecnt < 0 || typecnt > TZ_MAX_TYPES ||
timecnt < 0 || timecnt > TZ_MAX_TIMES ||
charcnt < 0 || charcnt > TZ_MAX_CHARS ||
ttisstdcnt < 0 || ttisstdcnt > TZ_MAX_TYPES ||
ttisutcnt < 0 || ttisutcnt > TZ_MAX_TYPES)
{
goto oops;
}
datablock_size = (timecnt * stored /* ats */
+ timecnt /* types */
+ typecnt * 6 /* ttinfos */
+ charcnt /* chars */
+ leapcnt * (stored + 4) /* lsinfos */
+ ttisstdcnt /* ttisstds */
+ ttisutcnt); /* ttisuts */
if (nread - tzheadsize < datablock_size)
{
goto oops;
}
if (skip_datablock)
{
p += datablock_size;
}
else
{
if (!((ttisstdcnt == typecnt || ttisstdcnt == 0) &&
(ttisutcnt == typecnt || ttisutcnt == 0)))
{
goto oops;
}
sp->leapcnt = leapcnt;
sp->timecnt = timecnt;
sp->typecnt = typecnt;
sp->charcnt = charcnt;
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])
{
goto oops;
}
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)
{
goto oops;
}
if (sp->types[i])
{
sp->types[timecnt++] = typ;
}
}
sp->timecnt = timecnt;
for (i = 0; i < sp->typecnt; ++i)
{
FAR struct ttinfo_s *ttisp;
unsigned char isdst;
unsigned char desigidx;
ttisp = &sp->ttis[i];
ttisp->tt_utoff = detzcode(p);
p += 4;
isdst = *p++;
if (isdst >= 2)
{
goto oops;
}
ttisp->tt_isdst = isdst;
desigidx = *p++;
if (desigidx >= sp->charcnt)
{
goto oops;
}
ttisp->tt_desigidx = desigidx;
}
for (i = 0; i < sp->charcnt; ++i)
{
sp->chars[i] = *p++;
}
/* Ensure '\0'-terminated, and make it safe to call
* ttunspecified later.
*/
memset(&sp->chars[i], 0, CHARS_EXTRA);
/* 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;
/* Leap seconds cannot occur before the Epoch,
* or out of order.
*/
if (tr <= prevtr)
{
goto oops;
}
/* To avoid other botches in this code, each leap second's
* correction must differ from the previous one's by 1
* second or less, except that the first correction can be
* any value; these requirements are more generous than
* RFC 8536, to allow future RFC extensions.
*/
if (!(i == 0 || (prevcorr < corr ? corr == prevcorr + 1 :
(corr == prevcorr ||
corr == prevcorr - 1))))
{
goto oops;
}
prevtr = tr;
prevcorr = corr;
if (tr <= TIME_T_MAX)
{
sp->lsis[leapcnt].ls_trans = tr;
sp->lsis[leapcnt].ls_corr = corr;
leapcnt++;
}
}
sp->leapcnt = leapcnt;
for (i = 0; i < sp->typecnt; ++i)
{
FAR struct ttinfo_s *ttisp;
ttisp = &sp->ttis[i];
if (ttisstdcnt == 0)
{
ttisp->tt_ttisstd = FALSE;
}
else
{
if (*p != TRUE && *p != FALSE)
{
goto oops;
}
ttisp->tt_ttisstd = *p++;
}
}
for (i = 0; i < sp->typecnt; ++i)
{
FAR struct ttinfo_s *ttisp;
ttisp = &sp->ttis[i];
if (ttisutcnt == 0)
{
ttisp->tt_ttisut = FALSE;
}
else
{
if (*p != TRUE && *p != FALSE)
{
goto oops;
}
ttisp->tt_ttisut = *p++;
}
}
}
nread -= p - up->buf;
for (i = 0; i < nread; ++i)
{
up->buf[i] = p[i];
}
/* If this is an old file, we're done. */
if (version == '\0')
{
break;
}
}
if (doextend && nread > 2 &&
up->buf[0] == '\n' && up->buf[nread - 1] == '\n' &&
sp->typecnt + 2 <= TZ_MAX_TYPES)
{
FAR struct state_s *ts = &lsp->u.st;
up->buf[nread - 1] = '\0';
if (tzparse(&up->buf[1], ts, sp) == 0)
{
/* Attempt to reuse existing abbreviations.
* Without this, America/Anchorage would be right on
* the edge after 2037 when TZ_MAX_CHARS is 50, as
* sp->charcnt equals 40 (for LMT AST AWT APT AHST
* AHDT YST AKDT AKST) and ts->charcnt equals 10
* (for AKST AKDT). Reusing means sp->charcnt can
* stay 40 in this example.
*/
int gotabbr = 0;
int charcnt = sp->charcnt;
for (i = 0; i < ts->typecnt; i++)
{
FAR char *tsabbr = ts->chars + ts->ttis[i].tt_desigidx;
int j;
for (j = 0; j < charcnt; j++)
{
if (strcmp(sp->chars + j, tsabbr) == 0)
{
ts->ttis[i].tt_desigidx = j;
gotabbr++;
break;
}
}
if (j >= charcnt)
{
int tsabbrlen = strlen(tsabbr);
if (j + tsabbrlen < TZ_MAX_CHARS)
{
strlcpy(sp->chars + j, tsabbr, sizeof(sp->chars) - j);
charcnt = j + tsabbrlen + 1;
ts->ttis[i].tt_desigidx = j;
gotabbr++;
}
}
}
if (gotabbr == ts->typecnt)
{
sp->charcnt = charcnt;
/* Ignore any trailing, no-op transitions generated
* by zic as they don't help here and can run afoul
* of bugs in zic 2016j or earlier.
*/
while (sp->timecnt > 1 && (sp->types[sp->timecnt - 1] ==
sp->types[sp->timecnt - 2]))
{
sp->timecnt--;
}
for (i = 0; i < ts->timecnt && sp->timecnt < TZ_MAX_TIMES; i++)
{
time_t t = ts->ats[i];
if (increment_overflow_time(&t, leapcorr(sp, t))
|| (0 < sp->timecnt && t <= sp->ats[sp->timecnt - 1]))
{
continue;
}
sp->ats[sp->timecnt] = t;
sp->types[sp->timecnt] = (sp->typecnt + ts->types[i]);
sp->timecnt++;
}
for (i = 0; i < ts->typecnt; i++)
{
sp->ttis[sp->typecnt++] = ts->ttis[i];
}
}
}
}
if (sp->typecnt == 0)
{
goto oops;
}
if (sp->timecnt > 1)
{
if (TIME_T_MAX > SECSPERREPEAT &&
sp->ats[0] <= TIME_T_MAX - SECSPERREPEAT)
{
time_t repeatat = sp->ats[0] + SECSPERREPEAT;
int repeattype = sp->types[0];
for (i = 1; i < sp->timecnt; ++i)
{
if (sp->ats[i] == repeatat &&
typesequiv(sp, sp->types[i], repeattype))
{
sp->goback = TRUE;
break;
}
}
}
if (TIME_T_MAX > SECSPERREPEAT &&
TIME_T_MIN + SECSPERREPEAT <= sp->ats[sp->timecnt - 1])
{
time_t repeatat = sp->ats[sp->timecnt - 1] - SECSPERREPEAT;
int repeattype = sp->types[sp->timecnt - 1];
for (i = sp->timecnt - 2; i >= 0; --i)
{
if (sp->ats[i] == repeatat &&
typesequiv(sp, sp->types[i], repeattype))
{
sp->goahead = TRUE;
break;
}
}
}
}
/* If type 0 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 && ! ttunspecified(sp, 0) ? -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;
lib_free(lsp);
return 0;
oops:
lib_free(lsp);
return -1;
}
static int typesequiv(FAR const struct state_s *sp, int a, int b)
{
int result;
if (sp == NULL || a < 0 || a >= sp->typecnt || b < 0 || b >= sp->typecnt)
{
result = FALSE;
}
else
{
FAR const struct ttinfo_s *ap = &sp->ttis[a];
FAR const struct ttinfo_s *bp = &sp->ttis[b];
result = ap->tt_utoff == bp->tt_utoff &&
ap->tt_isdst == bp->tt_isdst &&
ap->tt_ttisstd == bp->tt_ttisstd &&
ap->tt_ttisut == bp->tt_ttisut &&
strcmp(&sp->chars[ap->tt_desigidx],
&sp->chars[bp->tt_desigidx]) == 0;
}
return result;
}
/* 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 FAR const char *getzname(FAR const char *strp)
{
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 FAR const char *getqzname(FAR const char *strp, int delim)
{
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 FAR const char *getnum(FAR const char *strp, FAR int *nump,
int min, int max)
{
char c;
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 FAR const char *getsecs(FAR const char *strp,
FAR int_fast32_t *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 FAR const char *getoffset(FAR const char *strp,
FAR int_fast32_t *poffset)
{
int neg = FALSE;
if (*strp == '-')
{
neg = TRUE;
++strp;
}
else if (*strp == '+')
{
++strp;
}
strp = getsecs(strp, poffset);
if (strp == NULL)
{
return NULL; /* illegal time */
}
if (neg)
{
*poffset = -*poffset;
}
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 FAR const char *getrule(FAR const char *strp,
FAR struct rule_s *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 transtime(int year,
FAR const struct rule_s *rulep,
int_fast32_t offset)
{
int leap_year;
int_fast32_t value;
int i;
int d;
int m1;
int yy0;
int yy1;
int yy2;
int dow;
value = 0;
leap_year = 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 (leap_year && 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 >= g_mon_lengths[leap_year][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 += g_mon_lengths[leap_year][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 int tzparse(FAR const char *name, FAR struct state_s *sp,
FAR struct state_s *basep)
{
FAR const char *stdname;
FAR const char *dstname;
size_t stdlen;
size_t dstlen;
size_t charcnt;
int_fast32_t stdoffset;
int_fast32_t dstoffset;
FAR char *cp;
int load_ok;
time_t atlo = TIME_T_MIN;
time_t leaplo = TIME_T_MIN;
stdname = name;
if (*name == '<')
{
name++;
stdname = name;
name = getqzname(name, '>');
if (*name != '>')
{
return -1;
}
stdlen = name - stdname;
name++;
}
else
{
name = getzname(name);
stdlen = name - stdname;
}
if (stdlen == 0)
{
return -1;
}
name = getoffset(name, &stdoffset);
if (name == NULL)
{
return -1;
}
charcnt = stdlen + 1;
if (sizeof(sp->chars) < charcnt)
{
return -1;
}
if (basep)
{
if (0 < basep->timecnt)
{
atlo = basep->ats[basep->timecnt - 1];
}
load_ok = -1;
sp->leapcnt = basep->leapcnt;
memcpy(sp->lsis, basep->lsis, sp->leapcnt * sizeof(*sp->lsis));
}
else
{
load_ok = tzload(TZDEFRULES, sp, FALSE);
if (load_ok != 0)
{
sp->leapcnt = 0; /* so, we're off a little */
}
}
if (sp->leapcnt > 0)
{
leaplo = sp->lsis[sp->leapcnt - 1].ls_trans;
}
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 (dstlen == 0)
{
return -1;
}
charcnt += dstlen + 1;
if (sizeof(sp->chars) < charcnt)
{
return -1;
}
if (*name != '\0' && *name != ',' && *name != ';')
{
name = getoffset(name, &dstoffset);
if (name == NULL)
{
return -1;
}
}
else
{
dstoffset = stdoffset - SECSPERHOUR;
}
if (*name == '\0' && load_ok != 0)
{
name = TZDEFRULESTRING;
}
if (*name == ',' || *name == ';')
{
struct rule_s start;
struct rule_s end;
int year;
int yearlim;
int yearbeg;
int timecnt;
time_t janfirst;
int_fast32_t janoffset = 0;
++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 */
init_ttinfo(&sp->ttis[0], -stdoffset, FALSE, 0);
init_ttinfo(&sp->ttis[1], -dstoffset, TRUE, stdlen + 1);
sp->defaulttype = 0;
timecnt = 0;
janfirst = 0;
yearbeg = EPOCH_YEAR;
do
{
int_fast32_t yearsecs;
yearsecs = g_year_lengths[isleap(yearbeg - 1)] * SECSPERDAY;
yearbeg--;
if (increment_overflow_time(&janfirst, -yearsecs))
{
janoffset = -yearsecs;
break;
}
}
while (atlo < janfirst && (EPOCH_YEAR -
YEARSPERREPEAT / 2 < yearbeg));
while (true)
{
int_fast32_t yearsecs;
int yearbeg1 = yearbeg;
time_t janfirst1 = janfirst;
yearsecs = g_year_lengths[isleap(yearbeg)] * SECSPERDAY;
if (increment_overflow_time(&janfirst1, yearsecs) ||
increment_overflow(&yearbeg1, 1) || atlo <= janfirst1)
{
break;
}
yearbeg = yearbeg1;
janfirst = janfirst1;
}
yearlim = yearbeg;
if (increment_overflow(&yearlim, YEARSPERREPEAT + 1))
{
yearlim = INT_MAX;
}
for (year = yearbeg; year < yearlim; year++)
{
int_fast32_t
starttime = transtime(year, &start, stdoffset);
int_fast32_t
endtime = transtime(year, &end, dstoffset);
int_fast32_t
yearsecs = (g_year_lengths[isleap(year)] * SECSPERDAY);
int reversed = endtime < starttime;
if (reversed)
{
int_fast32_t swap = starttime;
starttime = endtime;
endtime = swap;
}
if (reversed ||
(starttime < endtime &&
(endtime - starttime < yearsecs)))
{
if (TZ_MAX_TIMES - 2 < timecnt)
{
break;
}
sp->ats[timecnt] = janfirst;
if (!increment_overflow_time(&sp->ats[timecnt],
janoffset + starttime) &&
atlo <= sp->ats[timecnt])
{
sp->types[timecnt++] = !reversed;
}
sp->ats[timecnt] = janfirst;
if (!increment_overflow_time(&sp->ats[timecnt],
janoffset + endtime) &&
atlo <= sp->ats[timecnt])
{
sp->types[timecnt++] = reversed;
}
}
if (endtime < leaplo)
{
yearlim = year;
if (increment_overflow(&yearlim, YEARSPERREPEAT + 1))
{
yearlim = INT_MAX;
}
}
if (increment_overflow_time(&janfirst, janoffset + yearsecs))
{
break;
}
janoffset = 0;
}
sp->timecnt = timecnt;
if (!timecnt)
{
sp->ttis[0] = sp->ttis[1];
sp->typecnt = 1; /* Perpetual DST. */
}
else if (YEARSPERREPEAT < year - yearbeg)
{
sp->goback = sp->goahead = TRUE;
}
}
else
{
int_fast32_t theirstdoffset;
int_fast32_t theirdstoffset;
int_fast32_t theiroffset;
int isdst;
int i;
int j;
if (*name != '\0')
{
return -1;
}
/* Initial value of theirstdoffset */
theirstdoffset = 0;
for (i = 0; i < sp->timecnt; ++i)
{
j = sp->types[i];
if (!sp->ttis[j].tt_isdst)
{
theirstdoffset = -sp->ttis[j].tt_utoff;
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_utoff;
break;
}
}
/* Initially we're assumed to be in standard time */
isdst = -1;
/* 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_ttisut)
{
/* No adjustment to transition time */
}
else
{
/* If daylight saving time is in
* effect, and the transition time was
* not specified as standard time, add
* the daylight saving 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_utoff;
if (sp->ttis[j].tt_isdst)
{
theirstdoffset = theiroffset;
}
else
{
theirdstoffset = 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 0;
}
static void gmtload(FAR struct state_s *sp)
{
if (tzload(g_etc_utc, sp, TRUE) != 0)
{
tzparse("UTC0", sp, NULL);
}
}
/* 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.)
*
* The unused offset argument is for the benefit of mktime variants.
*/
static FAR struct tm *localsub(FAR const time_t *timep,
int_fast32_t offset, FAR struct tm *tmp)
{
FAR struct state_s *sp;
FAR const struct ttinfo_s *ttisp;
int i;
FAR struct tm *result;
const time_t t = *timep;
sp = g_lcl_ptr;
if (sp == NULL)
{
return gmtsub(timep, offset, tmp);
}
if (nxrmutex_is_hold(&g_lcl_lock))
{
return NULL;
}
tz_lock(&g_lcl_lock);
if ((sp->goback && t < sp->ats[0]) ||
(sp->goahead && t > sp->ats[sp->timecnt - 1]))
{
time_t newt = t;
time_t seconds;
time_t years;
if (t < sp->ats[0])
{
seconds = sp->ats[0] - t;
}
else
{
seconds = t - sp->ats[sp->timecnt - 1];
}
--seconds;
/* Beware integer overflow, as SECONDS might be close
* to the maximum time_t.
*/
years = seconds / SECSPERREPEAT * YEARSPERREPEAT;
seconds = years * AVGSECSPERYEAR;
years += YEARSPERREPEAT;
if (t < sp->ats[0])
{
newt += seconds + SECSPERREPEAT;
}
else
{
newt -= seconds + SECSPERREPEAT;
}
if (newt < sp->ats[0] || newt > sp->ats[sp->timecnt - 1])
{
tz_unlock(&g_lcl_lock);
return NULL; /* "cannot happen" */
}
result = localsub(&newt, offset, tmp);
if (result != NULL)
{
int_fast64_t newy;
newy = result->tm_year;
if (t < sp->ats[0])
{
newy -= years;
}
else
{
newy += years;
}
if (newy < INT_MIN || newy > INT_MAX)
{
tz_unlock(&g_lcl_lock);
return NULL;
}
result->tm_year = newy;
}
tz_unlock(&g_lcl_lock);
return result;
}
if (sp->timecnt == 0 || t < sp->ats[0])
{
i = sp->defaulttype;
}
else
{
int lo = 1;
int hi = sp->timecnt;
while (lo < hi)
{
int mid = (lo + hi) >> 1;
if (t < sp->ats[mid])
{
hi = mid;
}
else
{
lo = mid + 1;
}
}
i = 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_utoff;
* timesub(&t, 0L, sp, tmp);
*/
result = timesub(&t, ttisp->tt_utoff, sp, tmp);
if (result != NULL)
{
result->tm_isdst = ttisp->tt_isdst;
tzname[result->tm_isdst] = &sp->chars[ttisp->tt_desigidx];
result->tm_zone = tzname[result->tm_isdst];
}
tz_unlock(&g_lcl_lock);
return result;
}
/* gmtsub is to gmtime as localsub is to localtime */
static FAR struct tm *gmtsub(FAR const time_t *timep,
int_fast32_t offset, FAR struct tm *tmp)
{
if (!g_gmt_isset)
{
tz_lock(&g_gmt_lock);
if (!g_gmt_isset)
{
g_gmt_ptr = lib_malloc(sizeof(*g_gmt_ptr));
if (g_gmt_ptr != NULL)
{
gmtload(g_gmt_ptr);
g_gmt_isset = 1;
}
}
tz_unlock(&g_gmt_lock);
}
tmp->tm_zone = ((FAR char *)(offset ? g_wildabbr :
g_gmt_ptr ? g_gmt_ptr->chars : g_utc));
return timesub(timep, offset, g_gmt_ptr, tmp);
}
/* 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 time_t leaps_thru_end_of_nonneg(time_t y)
{
return y / 4 - y / 100 + y / 400;
}
static time_t leaps_thru_end_of(time_t y)
{
return (y < 0 ? -1 - leaps_thru_end_of_nonneg(-1 - y)
: leaps_thru_end_of_nonneg(y));
}
static FAR struct tm *timesub(FAR const time_t *timep,
int_fast32_t offset,
FAR const struct state_s *sp,
FAR struct tm *tmp)
{
FAR const struct lsinfo_s *lp;
FAR const int *ip;
int_fast32_t rem;
int_fast32_t idays;
int_fast32_t dayoff;
int_fast32_t dayrem;
int_fast32_t corr;
time_t tdays;
time_t y;
int i;
/* If less than SECSPERMIN, the number of seconds since the
* most recent positive leap second; otherwise, do not add 1
* to localtime tm_sec because of leap seconds.
*/
time_t secs_since_posleap = SECSPERMIN;
corr = 0;
i = (sp == NULL) ? 0 : sp->leapcnt;
while (--i >= 0)
{
lp = &sp->lsis[i];
if (*timep >= lp->ls_trans)
{
corr = lp->ls_corr;
if ((i == 0 && corr > 0) || corr > lp[0 - 1].ls_corr)
{
secs_since_posleap = *timep - lp->ls_trans;
}
break;
}
}
/* Calculate the year, avoiding integer overflow even if
* time_t is unsigned.
*/
tdays = *timep / SECSPERDAY;
rem = *timep % SECSPERDAY;
rem += offset % SECSPERDAY - corr % SECSPERDAY + 3 * SECSPERDAY;
dayoff = offset / SECSPERDAY - corr / SECSPERDAY + rem / SECSPERDAY - 3;
rem %= SECSPERDAY;
/* y = (EPOCH_YEAR
* + floor((tdays + dayoff) / DAYSPERREPEAT) * YEARSPERREPEAT),
* sans overflow. But calculate against 1570 (EPOCH_YEAR -
* YEARSPERREPEAT) instead of against 1970 so that things work
* for localtime values before 1970 when time_t is unsigned.
*/
dayrem = tdays % DAYSPERREPEAT;
dayrem += dayoff % DAYSPERREPEAT;
y = (EPOCH_YEAR - YEARSPERREPEAT +
((1 + dayoff / DAYSPERREPEAT + dayrem / DAYSPERREPEAT -
((dayrem % DAYSPERREPEAT) < 0) + tdays / DAYSPERREPEAT)
* YEARSPERREPEAT));
/* idays = (tdays + dayoff) mod DAYSPERREPEAT, sans overflow. */
idays = tdays % DAYSPERREPEAT;
idays += dayoff % DAYSPERREPEAT + 2 * DAYSPERREPEAT;
idays %= DAYSPERREPEAT;
/* Increase Y and decrease IDAYS until IDAYS is in range for Y. */
while (idays >= g_year_lengths[isleap(y)])
{
time_t newy;
int tdelta;
int_fast32_t ydelta;
int leapdays;
tdelta = idays / DAYSPERLYEAR;
ydelta = tdelta + !tdelta;
newy = y + ydelta;
leapdays = leaps_thru_end_of(newy - 1) - leaps_thru_end_of(y - 1);
idays -= ydelta * DAYSPERNYEAR;
idays -= leapdays;
y = newy;
}
if (!TYPE_SIGNED(time_t) && y < TM_YEAR_BASE)
{
int signed_y = y;
tmp->tm_year = signed_y - TM_YEAR_BASE;
}
else if ((!TYPE_SIGNED(time_t) || INT_MIN + TM_YEAR_BASE <= y)
&& y - TM_YEAR_BASE <= INT_MAX)
{
tmp->tm_year = y - TM_YEAR_BASE;
}
else
{
set_errno(EOVERFLOW);
return NULL;
}
tmp->tm_yday = idays;
/* The "extra" mods below avoid overflow problems */
tmp->tm_wday = TM_WDAY_BASE +
((tmp->tm_year % DAYSPERWEEK) *
(DAYSPERNYEAR % DAYSPERWEEK)) +
leaps_thru_end_of(y - 1) - leaps_thru_end_of(TM_YEAR_BASE - 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);
tmp->tm_sec = (int)(rem % SECSPERMIN);
/* Use "... ??:??:60" at the end of the localtime minute containing
* the second just before the positive leap second.
*/
tmp->tm_sec += secs_since_posleap <= tmp->tm_sec;
ip = g_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;
tmp->tm_gmtoff = offset;
return tmp;
}
/* 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).
*/
/* Normalize logic courtesy Paul Eggert */
static int increment_overflow(FAR int *ip, int j)
{
const int 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 int increment_overflow32(FAR int_fast32_t *lp, int m)
{
const int_fast32_t l = *lp;
if ((l >= 0) ? (m > INT_FAST32_MAX - l) : (m < INT_FAST32_MIN - l))
{
return TRUE;
}
*lp += m;
return FALSE;
}
static int increment_overflow_time(FAR 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 int normalize_overflow(FAR int *tensptr,
FAR int *unitsptr, int base)
{
int tensdelta;
tensdelta = (*unitsptr >= 0) ?
(*unitsptr / base) : (-1 - (-1 - *unitsptr) / base);
*unitsptr -= tensdelta * base;
return increment_overflow(tensptr, tensdelta);
}
static int normalize_overflow32(FAR int_fast32_t *tensptr,
FAR int *unitsptr, int base)
{
int tensdelta;
tensdelta = (*unitsptr >= 0) ?
(*unitsptr / base) : (-1 - (-1 - *unitsptr) / base);
*unitsptr -= tensdelta * base;
return increment_overflow32(tensptr, tensdelta);
}
static int tmcomp(FAR const struct tm *atmp, FAR const struct tm *btmp)
{
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(FAR struct tm *tmp,
FAR struct tm *(*funcp)(FAR const time_t *,
int_fast32_t, FAR struct tm *),
int_fast32_t offset, FAR int *okayp,
int do_norm_secs)
{
FAR const struct state_s *sp;
int dir;
int i;
int j;
int saved_seconds;
int_fast32_t li;
time_t lo;
time_t hi;
int_fast32_t y;
time_t newt;
time_t t;
struct tm yourtm;
struct tm mytm;
*okayp = FALSE;
yourtm = *tmp;
if (do_norm_secs)
{
if (normalize_overflow(&yourtm.tm_min, &yourtm.tm_sec, SECSPERMIN))
{
return -1;
}
}
if (normalize_overflow(&yourtm.tm_hour, &yourtm.tm_min, MINSPERHOUR))
{
return -1;
}
if (normalize_overflow(&yourtm.tm_mday, &yourtm.tm_hour, HOURSPERDAY))
{
return -1;
}
y = yourtm.tm_year;
if (normalize_overflow32(&y, &yourtm.tm_mon, MONSPERYEAR))
{
return -1;
}
/* 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 -1;
}
while (yourtm.tm_mday <= 0)
{
if (increment_overflow32(&y, -1))
{
return -1;
}
li = y + (1 < yourtm.tm_mon);
yourtm.tm_mday += g_year_lengths[isleap(li)];
}
while (yourtm.tm_mday > DAYSPERLYEAR)
{
li = y + (1 < yourtm.tm_mon);
yourtm.tm_mday -= g_year_lengths[isleap(li)];
if (increment_overflow32(&y, 1))
{
return -1;
}
}
for (; ; )
{
i = g_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 -1;
}
}
}
if (increment_overflow32(&y, -TM_YEAR_BASE))
{
return -1;
}
if (y < INT_MIN || y > INT_MAX)
{
return -1;
}
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 -1;
}
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)(&t, offset, &mytm) == NULL)
{
/* 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 -1;
}
++t;
++lo;
}
else if (t == hi)
{
if (t == TIME_T_MIN)
{
return -1;
}
--t;
--hi;
}
if (lo > hi)
{
return -1;
}
if (dir > 0)
{
hi = t;
}
else
{
lo = t;
}
continue;
}
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.
*/
sp = (FAR const struct state_s *)
((funcp == localsub) ? g_lcl_ptr : g_gmt_ptr);
if (sp == NULL)
{
return -1;
}
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_utoff - sp->ttis[i].tt_utoff;
if ((*funcp) (&newt, offset, &mytm) == NULL)
{
continue;
}
if (tmcomp(&mytm, &yourtm) != 0)
{
continue;
}
if (mytm.tm_isdst != yourtm.tm_isdst)
{
continue;
}
/* We have a match */
t = newt;
goto label;
}
}
return -1;
}
label:
newt = t + saved_seconds;
if ((newt < t) != (saved_seconds < 0))
{
return -1;
}
t = newt;
if ((*funcp) (&t, offset, tmp))
{
*okayp = TRUE;
}
return t;
}
static time_t time2(FAR struct tm *tmp,
FAR struct tm *(*funcp)(FAR const time_t *,
int_fast32_t, FAR struct tm *),
int_fast32_t offset, FAR int *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, offset, okayp, FALSE);
return *okayp ? t : time2sub(tmp, funcp, offset, okayp, TRUE);
}
static time_t time1(FAR struct tm *tmp,
FAR struct tm *(*funcp)(FAR const time_t *,
int_fast32_t, FAR struct tm *),
int_fast32_t offset)
{
time_t t;
FAR const struct state_s *sp;
int samei;
int otheri;
int sameind;
int otherind;
int i;
int nseen;
char seen[TZ_MAX_TYPES];
unsigned char types[TZ_MAX_TYPES];
int okay;
if (tmp == NULL)
{
set_errno(EINVAL);
return -1;
}
if (tmp->tm_isdst > 1)
{
tmp->tm_isdst = 1;
}
t = time2(tmp, funcp, offset, &okay);
if (okay)
{
return t;
}
if (tmp->tm_isdst < 0)
{
return t;
}
/* 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.
*/
sp = ((funcp == localsub) ? g_lcl_ptr : g_gmt_ptr);
if (sp == NULL)
{
return -1;
}
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]] && !ttunspecified(sp, 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_utoff -
sp->ttis[samei].tt_utoff;
tmp->tm_isdst = !tmp->tm_isdst;
t = time2(tmp, funcp, offset, &okay);
if (okay)
{
return t;
}
tmp->tm_sec -= sp->ttis[otheri].tt_utoff -
sp->ttis[samei].tt_utoff;
tmp->tm_isdst = !tmp->tm_isdst;
}
}
return -1;
}
/* Initialize *SP to a value appropriate for the TZ setting NAME.
* Return 0 on success, an errno value on failure.
*/
static int zoneinit(FAR const char *name)
{
if (name != NULL && name[0] == '\0')
{
/* User wants it fast rather than right */
g_lcl_ptr->leapcnt = 0; /* so, we're off a little */
g_lcl_ptr->timecnt = 0;
g_lcl_ptr->typecnt = 0;
g_lcl_ptr->charcnt = 0;
g_lcl_ptr->goback = 0;
g_lcl_ptr->goahead = 0;
init_ttinfo(&g_lcl_ptr->ttis[0], 0, FALSE, 0);
strlcpy(g_lcl_ptr->chars, g_utc, sizeof(g_lcl_ptr->chars));
g_lcl_ptr->defaulttype = 0;
return 0;
}
else
{
int err;
err = tzload(name, g_lcl_ptr, TRUE);
if (err != 0 && name != NULL && name[0] == ':' &&
tzparse(name, g_lcl_ptr, NULL) != 0)
{
err = 0;
}
if (err == 0)
{
scrub_abbrs(g_lcl_ptr);
}
return err;
}
}
/****************************************************************************
* Public Functions
****************************************************************************/
void tzset(void)
{
FAR const char *name;
name = getenv("TZ");
if (name == NULL)
{
return;
}
if (g_lcl_isset > 0 && strcmp(g_lcl_tzname, name) == 0)
{
return;
}
if (nxrmutex_is_hold(&g_lcl_lock))
{
return;
}
tz_lock(&g_lcl_lock);
if (g_lcl_ptr == NULL)
{
g_lcl_ptr = lib_malloc(sizeof(*g_lcl_ptr));
if (g_lcl_ptr == NULL)
{
goto tzname;
}
}
if (zoneinit(name) != 0)
{
zoneinit("");
}
strlcpy(g_lcl_tzname, name, sizeof(g_lcl_tzname));
tzname:
settzname();
g_lcl_isset = 1;
tz_unlock(&g_lcl_lock);
}
FAR struct tm *localtime(FAR const time_t *timep)
{
tzset();
return localsub(timep, 0L, &g_tm);
}
/* Re-entrant version of localtime */
FAR struct tm *localtime_r(FAR const time_t *timep, FAR struct tm *tmp)
{
tzset();
return localsub(timep, 0L, tmp);
}
FAR struct tm *gmtime(FAR const time_t *timep)
{
return gmtsub(timep, 0L, &g_tm);
}
/* Re-entrant version of gmtime */
FAR struct tm *gmtime_r(FAR const time_t *timep, FAR struct tm *tmp)
{
return gmtsub(timep, 0L, tmp);
}
time_t mktime(FAR struct tm *tmp)
{
tzset();
return time1(tmp, localsub, 0L);
}
time_t timegm(FAR struct tm *tmp)
{
if (tmp != NULL)
{
tmp->tm_isdst = 0;
}
return time1(tmp, gmtsub, 0L);
}
Reference in New Issue View Git Blame Copy Permalink