mirror of
git://sourceware.org/git/glibc.git
synced 2024-12-09 04:11:27 +08:00
5cffc05ed5
[BZ#18333] * time/tzset.c (__tzfile_read): Check tzspec_len == 0.
852 lines
23 KiB
C
852 lines
23 KiB
C
/* Copyright (C) 1991-2015 Free Software Foundation, Inc.
|
||
This file is part of the GNU C Library.
|
||
|
||
The GNU C Library is free software; you can redistribute it and/or
|
||
modify it under the terms of the GNU Lesser General Public
|
||
License as published by the Free Software Foundation; either
|
||
version 2.1 of the License, or (at your option) any later version.
|
||
|
||
The GNU C Library is distributed in the hope that it will be useful,
|
||
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
||
Lesser General Public License for more details.
|
||
|
||
You should have received a copy of the GNU Lesser General Public
|
||
License along with the GNU C Library; if not, see
|
||
<http://www.gnu.org/licenses/>. */
|
||
|
||
#include <assert.h>
|
||
#include <limits.h>
|
||
#include <stdio.h>
|
||
#include <stdio_ext.h>
|
||
#include <stdlib.h>
|
||
#include <string.h>
|
||
#include <time.h>
|
||
#include <unistd.h>
|
||
#include <sys/stat.h>
|
||
#include <stdint.h>
|
||
|
||
#define NOID
|
||
#include <timezone/tzfile.h>
|
||
|
||
int __use_tzfile;
|
||
static dev_t tzfile_dev;
|
||
static ino64_t tzfile_ino;
|
||
static time_t tzfile_mtime;
|
||
|
||
struct ttinfo
|
||
{
|
||
long int offset; /* Seconds east of GMT. */
|
||
unsigned char isdst; /* Used to set tm_isdst. */
|
||
unsigned char idx; /* Index into `zone_names'. */
|
||
unsigned char isstd; /* Transition times are in standard time. */
|
||
unsigned char isgmt; /* Transition times are in GMT. */
|
||
};
|
||
|
||
struct leap
|
||
{
|
||
time_t transition; /* Time the transition takes effect. */
|
||
long int change; /* Seconds of correction to apply. */
|
||
};
|
||
|
||
static void compute_tzname_max (size_t) internal_function;
|
||
|
||
static size_t num_transitions;
|
||
libc_freeres_ptr (static time_t *transitions);
|
||
static unsigned char *type_idxs;
|
||
static size_t num_types;
|
||
static struct ttinfo *types;
|
||
static char *zone_names;
|
||
static long int rule_stdoff;
|
||
static long int rule_dstoff;
|
||
static size_t num_leaps;
|
||
static struct leap *leaps;
|
||
static char *tzspec;
|
||
|
||
#include <endian.h>
|
||
#include <byteswap.h>
|
||
|
||
/* Decode the four bytes at PTR as a signed integer in network byte order. */
|
||
static inline int
|
||
__attribute ((always_inline))
|
||
decode (const void *ptr)
|
||
{
|
||
if (BYTE_ORDER == BIG_ENDIAN && sizeof (int) == 4)
|
||
return *(const int *) ptr;
|
||
if (sizeof (int) == 4)
|
||
return bswap_32 (*(const int *) ptr);
|
||
|
||
const unsigned char *p = ptr;
|
||
int result = *p & (1 << (CHAR_BIT - 1)) ? ~0 : 0;
|
||
|
||
result = (result << 8) | *p++;
|
||
result = (result << 8) | *p++;
|
||
result = (result << 8) | *p++;
|
||
result = (result << 8) | *p++;
|
||
|
||
return result;
|
||
}
|
||
|
||
|
||
static inline int64_t
|
||
__attribute ((always_inline))
|
||
decode64 (const void *ptr)
|
||
{
|
||
if ((BYTE_ORDER == BIG_ENDIAN))
|
||
return *(const int64_t *) ptr;
|
||
|
||
return bswap_64 (*(const int64_t *) ptr);
|
||
}
|
||
|
||
|
||
void
|
||
__tzfile_read (const char *file, size_t extra, char **extrap)
|
||
{
|
||
static const char default_tzdir[] = TZDIR;
|
||
size_t num_isstd, num_isgmt;
|
||
FILE *f;
|
||
struct tzhead tzhead;
|
||
size_t chars;
|
||
size_t i;
|
||
size_t total_size;
|
||
size_t types_idx;
|
||
size_t leaps_idx;
|
||
int was_using_tzfile = __use_tzfile;
|
||
int trans_width = 4;
|
||
size_t tzspec_len;
|
||
char *new = NULL;
|
||
|
||
if (sizeof (time_t) != 4 && sizeof (time_t) != 8)
|
||
abort ();
|
||
|
||
__use_tzfile = 0;
|
||
|
||
if (file == NULL)
|
||
/* No user specification; use the site-wide default. */
|
||
file = TZDEFAULT;
|
||
else if (*file == '\0')
|
||
/* User specified the empty string; use UTC with no leap seconds. */
|
||
goto ret_free_transitions;
|
||
else
|
||
{
|
||
/* We must not allow to read an arbitrary file in a setuid
|
||
program. So we fail for any file which is not in the
|
||
directory hierachy starting at TZDIR
|
||
and which is not the system wide default TZDEFAULT. */
|
||
if (__libc_enable_secure
|
||
&& ((*file == '/'
|
||
&& memcmp (file, TZDEFAULT, sizeof TZDEFAULT)
|
||
&& memcmp (file, default_tzdir, sizeof (default_tzdir) - 1))
|
||
|| strstr (file, "../") != NULL))
|
||
/* This test is certainly a bit too restrictive but it should
|
||
catch all critical cases. */
|
||
goto ret_free_transitions;
|
||
}
|
||
|
||
if (*file != '/')
|
||
{
|
||
const char *tzdir;
|
||
|
||
tzdir = getenv ("TZDIR");
|
||
if (tzdir == NULL || *tzdir == '\0')
|
||
tzdir = default_tzdir;
|
||
if (__asprintf (&new, "%s/%s", tzdir, file) == -1)
|
||
goto ret_free_transitions;
|
||
file = new;
|
||
}
|
||
|
||
/* If we were already using tzfile, check whether the file changed. */
|
||
struct stat64 st;
|
||
if (was_using_tzfile
|
||
&& stat64 (file, &st) == 0
|
||
&& tzfile_ino == st.st_ino && tzfile_dev == st.st_dev
|
||
&& tzfile_mtime == st.st_mtime)
|
||
goto done; /* Nothing to do. */
|
||
|
||
/* Note the file is opened with cancellation in the I/O functions
|
||
disabled and if available FD_CLOEXEC set. */
|
||
f = fopen (file, "rce");
|
||
if (f == NULL)
|
||
goto ret_free_transitions;
|
||
|
||
/* Get information about the file we are actually using. */
|
||
if (fstat64 (__fileno (f), &st) != 0)
|
||
{
|
||
fclose (f);
|
||
goto ret_free_transitions;
|
||
}
|
||
|
||
free ((void *) transitions);
|
||
transitions = NULL;
|
||
|
||
/* Remember the inode and device number and modification time. */
|
||
tzfile_dev = st.st_dev;
|
||
tzfile_ino = st.st_ino;
|
||
tzfile_mtime = st.st_mtime;
|
||
|
||
/* No threads reading this stream. */
|
||
__fsetlocking (f, FSETLOCKING_BYCALLER);
|
||
|
||
read_again:
|
||
if (__builtin_expect (__fread_unlocked ((void *) &tzhead, sizeof (tzhead),
|
||
1, f) != 1, 0)
|
||
|| memcmp (tzhead.tzh_magic, TZ_MAGIC, sizeof (tzhead.tzh_magic)) != 0)
|
||
goto lose;
|
||
|
||
num_transitions = (size_t) decode (tzhead.tzh_timecnt);
|
||
num_types = (size_t) decode (tzhead.tzh_typecnt);
|
||
chars = (size_t) decode (tzhead.tzh_charcnt);
|
||
num_leaps = (size_t) decode (tzhead.tzh_leapcnt);
|
||
num_isstd = (size_t) decode (tzhead.tzh_ttisstdcnt);
|
||
num_isgmt = (size_t) decode (tzhead.tzh_ttisgmtcnt);
|
||
|
||
if (__glibc_unlikely (num_isstd > num_types || num_isgmt > num_types))
|
||
goto lose;
|
||
|
||
/* For platforms with 64-bit time_t we use the new format if available. */
|
||
if (sizeof (time_t) == 8 && trans_width == 4
|
||
&& tzhead.tzh_version[0] != '\0')
|
||
{
|
||
/* We use the 8-byte format. */
|
||
trans_width = 8;
|
||
|
||
/* Position the stream before the second header. */
|
||
size_t to_skip = (num_transitions * (4 + 1)
|
||
+ num_types * 6
|
||
+ chars
|
||
+ num_leaps * 8
|
||
+ num_isstd
|
||
+ num_isgmt);
|
||
if (fseek (f, to_skip, SEEK_CUR) != 0)
|
||
goto lose;
|
||
|
||
goto read_again;
|
||
}
|
||
|
||
if (__builtin_expect (num_transitions
|
||
> ((SIZE_MAX - (__alignof__ (struct ttinfo) - 1))
|
||
/ (sizeof (time_t) + 1)), 0))
|
||
goto lose;
|
||
total_size = num_transitions * (sizeof (time_t) + 1);
|
||
total_size = ((total_size + __alignof__ (struct ttinfo) - 1)
|
||
& ~(__alignof__ (struct ttinfo) - 1));
|
||
types_idx = total_size;
|
||
if (__builtin_expect (num_types
|
||
> (SIZE_MAX - total_size) / sizeof (struct ttinfo), 0))
|
||
goto lose;
|
||
total_size += num_types * sizeof (struct ttinfo);
|
||
if (__glibc_unlikely (chars > SIZE_MAX - total_size))
|
||
goto lose;
|
||
total_size += chars;
|
||
if (__builtin_expect (__alignof__ (struct leap) - 1
|
||
> SIZE_MAX - total_size, 0))
|
||
goto lose;
|
||
total_size = ((total_size + __alignof__ (struct leap) - 1)
|
||
& ~(__alignof__ (struct leap) - 1));
|
||
leaps_idx = total_size;
|
||
if (__builtin_expect (num_leaps
|
||
> (SIZE_MAX - total_size) / sizeof (struct leap), 0))
|
||
goto lose;
|
||
total_size += num_leaps * sizeof (struct leap);
|
||
tzspec_len = 0;
|
||
if (sizeof (time_t) == 8 && trans_width == 8)
|
||
{
|
||
off_t rem = st.st_size - __ftello (f);
|
||
if (__builtin_expect (rem < 0
|
||
|| (size_t) rem < (num_transitions * (8 + 1)
|
||
+ num_types * 6
|
||
+ chars), 0))
|
||
goto lose;
|
||
tzspec_len = (size_t) rem - (num_transitions * (8 + 1)
|
||
+ num_types * 6
|
||
+ chars);
|
||
if (__builtin_expect (num_leaps > SIZE_MAX / 12
|
||
|| tzspec_len < num_leaps * 12, 0))
|
||
goto lose;
|
||
tzspec_len -= num_leaps * 12;
|
||
if (__glibc_unlikely (tzspec_len < num_isstd))
|
||
goto lose;
|
||
tzspec_len -= num_isstd;
|
||
if (__glibc_unlikely (tzspec_len == 0 || tzspec_len - 1 < num_isgmt))
|
||
goto lose;
|
||
tzspec_len -= num_isgmt + 1;
|
||
if (__glibc_unlikely (tzspec_len == 0
|
||
|| SIZE_MAX - total_size < tzspec_len))
|
||
goto lose;
|
||
}
|
||
if (__glibc_unlikely (SIZE_MAX - total_size - tzspec_len < extra))
|
||
goto lose;
|
||
|
||
/* Allocate enough memory including the extra block requested by the
|
||
caller. */
|
||
transitions = (time_t *) malloc (total_size + tzspec_len + extra);
|
||
if (transitions == NULL)
|
||
goto lose;
|
||
|
||
type_idxs = (unsigned char *) transitions + (num_transitions
|
||
* sizeof (time_t));
|
||
types = (struct ttinfo *) ((char *) transitions + types_idx);
|
||
zone_names = (char *) types + num_types * sizeof (struct ttinfo);
|
||
leaps = (struct leap *) ((char *) transitions + leaps_idx);
|
||
if (sizeof (time_t) == 8 && trans_width == 8)
|
||
tzspec = (char *) leaps + num_leaps * sizeof (struct leap) + extra;
|
||
else
|
||
tzspec = NULL;
|
||
if (extra > 0)
|
||
*extrap = (char *) &leaps[num_leaps];
|
||
|
||
if (sizeof (time_t) == 4 || __builtin_expect (trans_width == 8, 1))
|
||
{
|
||
if (__builtin_expect (__fread_unlocked (transitions, trans_width + 1,
|
||
num_transitions, f)
|
||
!= num_transitions, 0))
|
||
goto lose;
|
||
}
|
||
else
|
||
{
|
||
if (__builtin_expect (__fread_unlocked (transitions, 4,
|
||
num_transitions, f)
|
||
!= num_transitions, 0)
|
||
|| __builtin_expect (__fread_unlocked (type_idxs, 1, num_transitions,
|
||
f) != num_transitions, 0))
|
||
goto lose;
|
||
}
|
||
|
||
/* Check for bogus indices in the data file, so we can hereafter
|
||
safely use type_idxs[T] as indices into `types' and never crash. */
|
||
for (i = 0; i < num_transitions; ++i)
|
||
if (__glibc_unlikely (type_idxs[i] >= num_types))
|
||
goto lose;
|
||
|
||
if ((BYTE_ORDER != BIG_ENDIAN && (sizeof (time_t) == 4 || trans_width == 4))
|
||
|| (BYTE_ORDER == BIG_ENDIAN && sizeof (time_t) == 8
|
||
&& trans_width == 4))
|
||
{
|
||
/* Decode the transition times, stored as 4-byte integers in
|
||
network (big-endian) byte order. We work from the end of
|
||
the array so as not to clobber the next element to be
|
||
processed when sizeof (time_t) > 4. */
|
||
i = num_transitions;
|
||
while (i-- > 0)
|
||
transitions[i] = decode ((char *) transitions + i * 4);
|
||
}
|
||
else if (BYTE_ORDER != BIG_ENDIAN && sizeof (time_t) == 8)
|
||
{
|
||
/* Decode the transition times, stored as 8-byte integers in
|
||
network (big-endian) byte order. */
|
||
for (i = 0; i < num_transitions; ++i)
|
||
transitions[i] = decode64 ((char *) transitions + i * 8);
|
||
}
|
||
|
||
for (i = 0; i < num_types; ++i)
|
||
{
|
||
unsigned char x[4];
|
||
int c;
|
||
if (__builtin_expect (__fread_unlocked (x, 1,
|
||
sizeof (x), f) != sizeof (x),
|
||
0))
|
||
goto lose;
|
||
c = getc_unlocked (f);
|
||
if (__glibc_unlikely ((unsigned int) c > 1u))
|
||
goto lose;
|
||
types[i].isdst = c;
|
||
c = getc_unlocked (f);
|
||
if (__glibc_unlikely ((size_t) c > chars))
|
||
/* Bogus index in data file. */
|
||
goto lose;
|
||
types[i].idx = c;
|
||
types[i].offset = (long int) decode (x);
|
||
}
|
||
|
||
if (__glibc_unlikely (__fread_unlocked (zone_names, 1, chars, f) != chars))
|
||
goto lose;
|
||
|
||
for (i = 0; i < num_leaps; ++i)
|
||
{
|
||
unsigned char x[8];
|
||
if (__builtin_expect (__fread_unlocked (x, 1, trans_width, f)
|
||
!= trans_width, 0))
|
||
goto lose;
|
||
if (sizeof (time_t) == 4 || trans_width == 4)
|
||
leaps[i].transition = (time_t) decode (x);
|
||
else
|
||
leaps[i].transition = (time_t) decode64 (x);
|
||
|
||
if (__glibc_unlikely (__fread_unlocked (x, 1, 4, f) != 4))
|
||
goto lose;
|
||
leaps[i].change = (long int) decode (x);
|
||
}
|
||
|
||
for (i = 0; i < num_isstd; ++i)
|
||
{
|
||
int c = getc_unlocked (f);
|
||
if (__glibc_unlikely (c == EOF))
|
||
goto lose;
|
||
types[i].isstd = c != 0;
|
||
}
|
||
while (i < num_types)
|
||
types[i++].isstd = 0;
|
||
|
||
for (i = 0; i < num_isgmt; ++i)
|
||
{
|
||
int c = getc_unlocked (f);
|
||
if (__glibc_unlikely (c == EOF))
|
||
goto lose;
|
||
types[i].isgmt = c != 0;
|
||
}
|
||
while (i < num_types)
|
||
types[i++].isgmt = 0;
|
||
|
||
/* Read the POSIX TZ-style information if possible. */
|
||
if (sizeof (time_t) == 8 && tzspec != NULL)
|
||
{
|
||
/* Skip over the newline first. */
|
||
if (getc_unlocked (f) != '\n'
|
||
|| (__fread_unlocked (tzspec, 1, tzspec_len - 1, f)
|
||
!= tzspec_len - 1))
|
||
tzspec = NULL;
|
||
else
|
||
tzspec[tzspec_len - 1] = '\0';
|
||
}
|
||
else if (sizeof (time_t) == 4 && tzhead.tzh_version[0] != '\0')
|
||
{
|
||
/* Get the TZ string. */
|
||
if (__builtin_expect (__fread_unlocked ((void *) &tzhead,
|
||
sizeof (tzhead), 1, f) != 1, 0)
|
||
|| (memcmp (tzhead.tzh_magic, TZ_MAGIC, sizeof (tzhead.tzh_magic))
|
||
!= 0))
|
||
goto lose;
|
||
|
||
size_t num_transitions2 = (size_t) decode (tzhead.tzh_timecnt);
|
||
size_t num_types2 = (size_t) decode (tzhead.tzh_typecnt);
|
||
size_t chars2 = (size_t) decode (tzhead.tzh_charcnt);
|
||
size_t num_leaps2 = (size_t) decode (tzhead.tzh_leapcnt);
|
||
size_t num_isstd2 = (size_t) decode (tzhead.tzh_ttisstdcnt);
|
||
size_t num_isgmt2 = (size_t) decode (tzhead.tzh_ttisgmtcnt);
|
||
|
||
/* Position the stream before the second header. */
|
||
size_t to_skip = (num_transitions2 * (8 + 1)
|
||
+ num_types2 * 6
|
||
+ chars2
|
||
+ num_leaps2 * 12
|
||
+ num_isstd2
|
||
+ num_isgmt2);
|
||
off_t off;
|
||
if (fseek (f, to_skip, SEEK_CUR) != 0
|
||
|| (off = __ftello (f)) < 0
|
||
|| st.st_size < off + 2)
|
||
goto lose;
|
||
|
||
tzspec_len = st.st_size - off - 1;
|
||
if (tzspec_len == 0)
|
||
goto lose;
|
||
char *tzstr = malloc (tzspec_len);
|
||
if (tzstr == NULL)
|
||
goto lose;
|
||
if (getc_unlocked (f) != '\n'
|
||
|| (__fread_unlocked (tzstr, 1, tzspec_len - 1, f)
|
||
!= tzspec_len - 1))
|
||
{
|
||
free (tzstr);
|
||
goto lose;
|
||
}
|
||
tzstr[tzspec_len - 1] = '\0';
|
||
tzspec = __tzstring (tzstr);
|
||
free (tzstr);
|
||
}
|
||
|
||
/* Don't use an empty TZ string. */
|
||
if (tzspec != NULL && tzspec[0] == '\0')
|
||
tzspec = NULL;
|
||
|
||
fclose (f);
|
||
|
||
/* First "register" all timezone names. */
|
||
for (i = 0; i < num_types; ++i)
|
||
(void) __tzstring (&zone_names[types[i].idx]);
|
||
|
||
/* Find the standard and daylight time offsets used by the rule file.
|
||
We choose the offsets in the types of each flavor that are
|
||
transitioned to earliest in time. */
|
||
__tzname[0] = NULL;
|
||
__tzname[1] = NULL;
|
||
for (i = num_transitions; i > 0; )
|
||
{
|
||
int type = type_idxs[--i];
|
||
int dst = types[type].isdst;
|
||
|
||
if (__tzname[dst] == NULL)
|
||
{
|
||
int idx = types[type].idx;
|
||
|
||
__tzname[dst] = __tzstring (&zone_names[idx]);
|
||
|
||
if (__tzname[1 - dst] != NULL)
|
||
break;
|
||
}
|
||
}
|
||
if (__tzname[0] == NULL)
|
||
{
|
||
/* This should only happen if there are no transition rules.
|
||
In this case there should be only one single type. */
|
||
assert (num_types == 1);
|
||
__tzname[0] = __tzstring (zone_names);
|
||
}
|
||
if (__tzname[1] == NULL)
|
||
__tzname[1] = __tzname[0];
|
||
|
||
compute_tzname_max (chars);
|
||
|
||
if (num_transitions == 0)
|
||
/* Use the first rule (which should also be the only one). */
|
||
rule_stdoff = rule_dstoff = types[0].offset;
|
||
else
|
||
{
|
||
int stdoff_set = 0, dstoff_set = 0;
|
||
rule_stdoff = rule_dstoff = 0;
|
||
i = num_transitions - 1;
|
||
do
|
||
{
|
||
if (!stdoff_set && !types[type_idxs[i]].isdst)
|
||
{
|
||
stdoff_set = 1;
|
||
rule_stdoff = types[type_idxs[i]].offset;
|
||
}
|
||
else if (!dstoff_set && types[type_idxs[i]].isdst)
|
||
{
|
||
dstoff_set = 1;
|
||
rule_dstoff = types[type_idxs[i]].offset;
|
||
}
|
||
if (stdoff_set && dstoff_set)
|
||
break;
|
||
}
|
||
while (i-- > 0);
|
||
|
||
if (!dstoff_set)
|
||
rule_dstoff = rule_stdoff;
|
||
}
|
||
|
||
__daylight = rule_stdoff != rule_dstoff;
|
||
__timezone = -rule_stdoff;
|
||
|
||
done:
|
||
__use_tzfile = 1;
|
||
free (new);
|
||
return;
|
||
|
||
lose:
|
||
fclose (f);
|
||
ret_free_transitions:
|
||
free (new);
|
||
free ((void *) transitions);
|
||
transitions = NULL;
|
||
}
|
||
|
||
/* The user specified a hand-made timezone, but not its DST rules.
|
||
We will use the names and offsets from the user, and the rules
|
||
from the TZDEFRULES file. */
|
||
|
||
void
|
||
__tzfile_default (const char *std, const char *dst,
|
||
long int stdoff, long int dstoff)
|
||
{
|
||
size_t stdlen = strlen (std) + 1;
|
||
size_t dstlen = strlen (dst) + 1;
|
||
size_t i;
|
||
int isdst;
|
||
char *cp;
|
||
|
||
__tzfile_read (TZDEFRULES, stdlen + dstlen, &cp);
|
||
if (!__use_tzfile)
|
||
return;
|
||
|
||
if (num_types < 2)
|
||
{
|
||
__use_tzfile = 0;
|
||
return;
|
||
}
|
||
|
||
/* Ignore the zone names read from the file and use the given ones
|
||
instead. */
|
||
__mempcpy (__mempcpy (cp, std, stdlen), dst, dstlen);
|
||
zone_names = cp;
|
||
|
||
/* Now there are only two zones, regardless of what the file contained. */
|
||
num_types = 2;
|
||
|
||
/* Now correct the transition times for the user-specified standard and
|
||
daylight offsets from GMT. */
|
||
isdst = 0;
|
||
for (i = 0; i < num_transitions; ++i)
|
||
{
|
||
struct ttinfo *trans_type = &types[type_idxs[i]];
|
||
|
||
/* We will use only types 0 (standard) and 1 (daylight).
|
||
Fix up this transition to point to whichever matches
|
||
the flavor of its original type. */
|
||
type_idxs[i] = trans_type->isdst;
|
||
|
||
if (trans_type->isgmt)
|
||
/* The transition time is in GMT. No correction to apply. */ ;
|
||
else if (isdst && !trans_type->isstd)
|
||
/* The type says this transition is in "local wall clock time", and
|
||
wall clock time as of the previous transition was DST. Correct
|
||
for the difference between the rule's DST offset and the user's
|
||
DST offset. */
|
||
transitions[i] += dstoff - rule_dstoff;
|
||
else
|
||
/* This transition is in "local wall clock time", and wall clock
|
||
time as of this iteration is non-DST. Correct for the
|
||
difference between the rule's standard offset and the user's
|
||
standard offset. */
|
||
transitions[i] += stdoff - rule_stdoff;
|
||
|
||
/* The DST state of "local wall clock time" for the next iteration is
|
||
as specified by this transition. */
|
||
isdst = trans_type->isdst;
|
||
}
|
||
|
||
/* Now that we adjusted the transitions to the requested offsets,
|
||
reset the rule_stdoff and rule_dstoff values appropriately. They
|
||
are used elsewhere. */
|
||
rule_stdoff = stdoff;
|
||
rule_dstoff = dstoff;
|
||
|
||
/* Reset types 0 and 1 to describe the user's settings. */
|
||
types[0].idx = 0;
|
||
types[0].offset = stdoff;
|
||
types[0].isdst = 0;
|
||
types[1].idx = stdlen;
|
||
types[1].offset = dstoff;
|
||
types[1].isdst = 1;
|
||
|
||
/* Reset the zone names to point to the user's names. */
|
||
__tzname[0] = (char *) std;
|
||
__tzname[1] = (char *) dst;
|
||
|
||
/* Set the timezone. */
|
||
__timezone = -types[0].offset;
|
||
|
||
compute_tzname_max (stdlen + dstlen);
|
||
}
|
||
|
||
void
|
||
__tzfile_compute (time_t timer, int use_localtime,
|
||
long int *leap_correct, int *leap_hit,
|
||
struct tm *tp)
|
||
{
|
||
size_t i;
|
||
|
||
if (use_localtime)
|
||
{
|
||
__tzname[0] = NULL;
|
||
__tzname[1] = NULL;
|
||
|
||
if (__glibc_unlikely (num_transitions == 0 || timer < transitions[0]))
|
||
{
|
||
/* TIMER is before any transition (or there are no transitions).
|
||
Choose the first non-DST type
|
||
(or the first if they're all DST types). */
|
||
i = 0;
|
||
while (i < num_types && types[i].isdst)
|
||
{
|
||
if (__tzname[1] == NULL)
|
||
__tzname[1] = __tzstring (&zone_names[types[i].idx]);
|
||
|
||
++i;
|
||
}
|
||
|
||
if (i == num_types)
|
||
i = 0;
|
||
__tzname[0] = __tzstring (&zone_names[types[i].idx]);
|
||
if (__tzname[1] == NULL)
|
||
{
|
||
size_t j = i;
|
||
while (j < num_types)
|
||
if (types[j].isdst)
|
||
{
|
||
__tzname[1] = __tzstring (&zone_names[types[j].idx]);
|
||
break;
|
||
}
|
||
else
|
||
++j;
|
||
}
|
||
}
|
||
else if (__glibc_unlikely (timer >= transitions[num_transitions - 1]))
|
||
{
|
||
if (__glibc_unlikely (tzspec == NULL))
|
||
{
|
||
use_last:
|
||
i = num_transitions;
|
||
goto found;
|
||
}
|
||
|
||
/* Parse the POSIX TZ-style string. */
|
||
__tzset_parse_tz (tzspec);
|
||
|
||
/* Convert to broken down structure. If this fails do not
|
||
use the string. */
|
||
if (__glibc_unlikely (! __offtime (&timer, 0, tp)))
|
||
goto use_last;
|
||
|
||
/* Use the rules from the TZ string to compute the change. */
|
||
__tz_compute (timer, tp, 1);
|
||
|
||
/* If tzspec comes from posixrules loaded by __tzfile_default,
|
||
override the STD and DST zone names with the ones user
|
||
requested in TZ envvar. */
|
||
if (__glibc_unlikely (zone_names == (char *) &leaps[num_leaps]))
|
||
{
|
||
assert (num_types == 2);
|
||
__tzname[0] = __tzstring (zone_names);
|
||
__tzname[1] = __tzstring (&zone_names[strlen (zone_names) + 1]);
|
||
}
|
||
|
||
goto leap;
|
||
}
|
||
else
|
||
{
|
||
/* Find the first transition after TIMER, and
|
||
then pick the type of the transition before it. */
|
||
size_t lo = 0;
|
||
size_t hi = num_transitions - 1;
|
||
/* Assume that DST is changing twice a year and guess initial
|
||
search spot from it.
|
||
Half of a gregorian year has on average 365.2425 * 86400 / 2
|
||
= 15778476 seconds. */
|
||
i = (transitions[num_transitions - 1] - timer) / 15778476;
|
||
if (i < num_transitions)
|
||
{
|
||
i = num_transitions - 1 - i;
|
||
if (timer < transitions[i])
|
||
{
|
||
if (i < 10 || timer >= transitions[i - 10])
|
||
{
|
||
/* Linear search. */
|
||
while (timer < transitions[i - 1])
|
||
--i;
|
||
goto found;
|
||
}
|
||
hi = i - 10;
|
||
}
|
||
else
|
||
{
|
||
if (i + 10 >= num_transitions || timer < transitions[i + 10])
|
||
{
|
||
/* Linear search. */
|
||
while (timer >= transitions[i])
|
||
++i;
|
||
goto found;
|
||
}
|
||
lo = i + 10;
|
||
}
|
||
}
|
||
|
||
/* Binary search. */
|
||
/* assert (timer >= transitions[lo] && timer < transitions[hi]); */
|
||
while (lo + 1 < hi)
|
||
{
|
||
i = (lo + hi) / 2;
|
||
if (timer < transitions[i])
|
||
hi = i;
|
||
else
|
||
lo = i;
|
||
}
|
||
i = hi;
|
||
|
||
found:
|
||
/* assert (timer >= transitions[i - 1]
|
||
&& (i == num_transitions || timer < transitions[i])); */
|
||
__tzname[types[type_idxs[i - 1]].isdst]
|
||
= __tzstring (&zone_names[types[type_idxs[i - 1]].idx]);
|
||
size_t j = i;
|
||
while (j < num_transitions)
|
||
{
|
||
int type = type_idxs[j];
|
||
int dst = types[type].isdst;
|
||
int idx = types[type].idx;
|
||
|
||
if (__tzname[dst] == NULL)
|
||
{
|
||
__tzname[dst] = __tzstring (&zone_names[idx]);
|
||
|
||
if (__tzname[1 - dst] != NULL)
|
||
break;
|
||
}
|
||
|
||
++j;
|
||
}
|
||
|
||
if (__glibc_unlikely (__tzname[0] == NULL))
|
||
__tzname[0] = __tzname[1];
|
||
|
||
i = type_idxs[i - 1];
|
||
}
|
||
|
||
struct ttinfo *info = &types[i];
|
||
__daylight = rule_stdoff != rule_dstoff;
|
||
__timezone = -rule_stdoff;
|
||
|
||
if (__tzname[0] == NULL)
|
||
{
|
||
/* This should only happen if there are no transition rules.
|
||
In this case there should be only one single type. */
|
||
assert (num_types == 1);
|
||
__tzname[0] = __tzstring (zone_names);
|
||
}
|
||
if (__tzname[1] == NULL)
|
||
/* There is no daylight saving time. */
|
||
__tzname[1] = __tzname[0];
|
||
tp->tm_isdst = info->isdst;
|
||
assert (strcmp (&zone_names[info->idx], __tzname[tp->tm_isdst]) == 0);
|
||
tp->tm_zone = __tzname[tp->tm_isdst];
|
||
tp->tm_gmtoff = info->offset;
|
||
}
|
||
|
||
leap:
|
||
*leap_correct = 0L;
|
||
*leap_hit = 0;
|
||
|
||
/* Find the last leap second correction transition time before TIMER. */
|
||
i = num_leaps;
|
||
do
|
||
if (i-- == 0)
|
||
return;
|
||
while (timer < leaps[i].transition);
|
||
|
||
/* Apply its correction. */
|
||
*leap_correct = leaps[i].change;
|
||
|
||
if (timer == leaps[i].transition && /* Exactly at the transition time. */
|
||
((i == 0 && leaps[i].change > 0) ||
|
||
leaps[i].change > leaps[i - 1].change))
|
||
{
|
||
*leap_hit = 1;
|
||
while (i > 0
|
||
&& leaps[i].transition == leaps[i - 1].transition + 1
|
||
&& leaps[i].change == leaps[i - 1].change + 1)
|
||
{
|
||
++*leap_hit;
|
||
--i;
|
||
}
|
||
}
|
||
}
|
||
|
||
static void
|
||
internal_function
|
||
compute_tzname_max (size_t chars)
|
||
{
|
||
const char *p;
|
||
|
||
p = zone_names;
|
||
do
|
||
{
|
||
const char *start = p;
|
||
while (*p != '\0')
|
||
++p;
|
||
if ((size_t) (p - start) > __tzname_cur_max)
|
||
__tzname_cur_max = p - start;
|
||
}
|
||
while (++p < &zone_names[chars]);
|
||
}
|