11 #define malloc __libc_malloc
18 char *__tzname
[2] = { 0, 0 };
20 weak_alias(__timezone
, timezone
);
21 weak_alias(__daylight
, daylight
);
22 weak_alias(__tzname
, tzname
);
24 static char std_name
[TZNAME_MAX
+1];
25 static char dst_name
[TZNAME_MAX
+1];
26 const char __utc
[] = "UTC";
29 static int r0
[5], r1
[5];
31 static const unsigned char *zi
, *trans
, *index
, *types
, *abbrevs
, *abbrevs_end
;
32 static size_t map_size
;
34 static char old_tz_buf
[32];
35 static char *old_tz
= old_tz_buf
;
36 static size_t old_tz_size
= sizeof old_tz_buf
;
38 static volatile int lock
[1];
39 volatile int *const __timezone_lockptr
= lock
;
41 static int getint(const char **p
)
44 for (x
=0; **p
-'0'<10U; (*p
)++) x
= **p
-'0' + 10*x
;
48 static int getoff(const char **p
)
54 } else if (**p
== '+') {
57 int off
= 3600*getint(p
);
66 return neg
? -off
: off
;
69 static void getrule(const char **p
, int rule
[5])
71 int r
= rule
[0] = **p
;
78 ++*p
; rule
[1] = getint(p
);
79 ++*p
; rule
[2] = getint(p
);
80 ++*p
; rule
[3] = getint(p
);
91 static void getname(char *d
, const char **p
)
96 for (i
=0; (*p
)[i
] && (*p
)[i
]!='>'; i
++)
97 if (i
<TZNAME_MAX
) d
[i
] = (*p
)[i
];
100 for (i
=0; ((*p
)[i
]|32)-'a'<26U; i
++)
101 if (i
<TZNAME_MAX
) d
[i
] = (*p
)[i
];
104 d
[i
<TZNAME_MAX
?i
:TZNAME_MAX
] = 0;
107 #define VEC(...) ((const unsigned char[]){__VA_ARGS__})
109 static uint32_t zi_read32(const unsigned char *z
)
111 return (unsigned)z
[0]<<24 | z
[1]<<16 | z
[2]<<8 | z
[3];
114 static size_t zi_dotprod(const unsigned char *z
, const unsigned char *v
, size_t n
)
118 for (y
=0; n
; n
--, z
+=4, v
++) {
125 static void do_tzset()
127 char buf
[NAME_MAX
+25], *pathname
=buf
+24;
128 const char *try, *s
, *p
;
129 const unsigned char *map
= 0;
131 static const char search
[] =
132 "/usr/share/zoneinfo/\0/share/zoneinfo/\0/etc/zoneinfo/\0";
135 if (!s
) s
= "/etc/localtime";
138 if (old_tz
&& !strcmp(s
, old_tz
)) return;
140 for (i
=0; i
<5; i
++) r0
[i
] = r1
[i
] = 0;
142 if (zi
) __munmap((void *)zi
, map_size
);
144 /* Cache the old value of TZ to check if it has changed. Avoid
145 * free so as not to pull it into static programs. Growth
146 * strategy makes it so free would have minimal benefit anyway. */
148 if (i
> PATH_MAX
+1) s
= __utc
, i
= 3;
149 if (i
>= old_tz_size
) {
151 if (i
>= old_tz_size
) old_tz_size
= i
+1;
152 if (old_tz_size
> PATH_MAX
+2) old_tz_size
= PATH_MAX
+2;
153 old_tz
= malloc(old_tz_size
);
155 if (old_tz
) memcpy(old_tz
, s
, i
+1);
157 /* Non-suid can use an absolute tzfile pathname or a relative
158 * pathame beginning with "."; in secure mode, only the
159 * standard path will be searched. */
160 if (*s
== ':' || ((p
=strchr(s
, '/')) && !memchr(s
, ',', p
-s
))) {
162 if (*s
== '/' || *s
== '.') {
163 if (!libc
.secure
|| !strcmp(s
, "/etc/localtime"))
164 map
= __map_file(s
, &map_size
);
166 size_t l
= strlen(s
);
167 if (l
<= NAME_MAX
&& !strchr(s
, '.')) {
168 memcpy(pathname
, s
, l
+1);
170 for (try=search
; !map
&& *try; try+=l
+1) {
172 memcpy(pathname
-l
, try, l
);
173 map
= __map_file(pathname
-l
, &map_size
);
179 if (map
&& (map_size
< 44 || memcmp(map
, "TZif", 4))) {
180 __munmap((void *)map
, map_size
);
189 size_t skip
= zi_dotprod(zi
+20, VEC(1,1,8,5,6,1), 6);
190 trans
= zi
+skip
+44+44;
195 index
= trans
+ (zi_read32(trans
-12) << scale
);
196 types
= index
+ zi_read32(trans
-12);
197 abbrevs
= types
+ 6*zi_read32(trans
-8);
198 abbrevs_end
= abbrevs
+ zi_read32(trans
-4);
199 if (zi
[map_size
-1] == '\n') {
200 for (s
= (const char *)zi
+map_size
-2; *s
!='\n'; s
--);
203 const unsigned char *p
;
204 __tzname
[0] = __tzname
[1] = 0;
205 __daylight
= __timezone
= dst_off
= 0;
206 for (p
=types
; p
<abbrevs
; p
+=6) {
207 if (!p
[4] && !__tzname
[0]) {
208 __tzname
[0] = (char *)abbrevs
+ p
[5];
209 __timezone
= -zi_read32(p
);
211 if (p
[4] && !__tzname
[1]) {
212 __tzname
[1] = (char *)abbrevs
+ p
[5];
213 dst_off
= -zi_read32(p
);
217 if (!__tzname
[0]) __tzname
[0] = __tzname
[1];
218 if (!__tzname
[0]) __tzname
[0] = (char *)__utc
;
220 __tzname
[1] = __tzname
[0];
221 dst_off
= __timezone
;
228 getname(std_name
, &s
);
229 __tzname
[0] = std_name
;
230 __timezone
= getoff(&s
);
231 getname(dst_name
, &s
);
232 __tzname
[1] = dst_name
;
235 if (*s
== '+' || *s
=='-' || *s
-'0'<10U)
236 dst_off
= getoff(&s
);
238 dst_off
= __timezone
- 3600;
241 dst_off
= __timezone
;
244 if (*s
== ',') s
++, getrule(&s
, r0
);
245 if (*s
== ',') s
++, getrule(&s
, r1
);
248 /* Search zoneinfo rules to find the one that applies to the given time,
249 * and determine alternate opposite-DST-status rule that may be needed. */
251 static size_t scan_trans(long long t
, int local
, size_t *alt
)
253 int scale
= 3 - (trans
== zi
+44);
257 size_t a
= 0, n
= (index
-trans
)>>scale
, m
;
264 /* Binary search for 'most-recent rule before t'. */
267 x
= zi_read32(trans
+ (m
<<scale
));
268 if (scale
== 3) x
= x
<<32 | zi_read32(trans
+ (m
<<scale
) + 4);
270 if (local
) off
= (int32_t)zi_read32(types
+ 6 * index
[m
-1]);
271 if (t
- off
< (int64_t)x
) {
279 /* First and last entry are special. First means to use lowest-index
280 * non-DST type. Last means to apply POSIX-style rule if available. */
281 n
= (index
-trans
)>>scale
;
282 if (a
== n
-1) return -1;
284 x
= zi_read32(trans
+ (a
<<scale
));
285 if (scale
== 3) x
= x
<<32 | zi_read32(trans
+ (a
<<scale
) + 4);
287 if (local
) off
= (int32_t)zi_read32(types
+ 6 * index
[a
-1]);
288 if (t
- off
< (int64_t)x
) {
289 for (a
=0; a
<(abbrevs
-types
)/6; a
++) {
290 if (types
[6*a
+4] != types
[4]) break;
292 if (a
== (abbrevs
-types
)/6) a
= 0;
303 /* Try to find a neighboring opposite-DST-status rule. */
305 if (a
&& types
[6*index
[a
-1]+4] != types
[6*index
[a
]+4])
307 else if (a
+1<n
&& types
[6*index
[a
+1]+4] != types
[6*index
[a
]+4])
316 static int days_in_month(int m
, int is_leap
)
318 if (m
==2) return 28+is_leap
;
319 else return 30+((0xad5>>(m
-1))&1);
322 /* Convert a POSIX DST rule plus year to seconds since epoch. */
324 static long long rule_to_secs(const int *rule
, int year
)
327 long long t
= __year_to_secs(year
, &is_leap
);
331 if (rule
[0]=='J' && (x
< 60 || !is_leap
)) x
--;
337 t
+= __month_to_secs(m
-1, is_leap
);
338 int wday
= (int)((t
+ 4*86400) % (7*86400)) / 86400;
340 if (days
< 0) days
+= 7;
341 if (n
== 5 && days
+28 >= days_in_month(m
, is_leap
)) n
= 4;
342 t
+= 86400 * (days
+ 7*(n
-1));
348 /* Determine the time zone in effect for a given time in seconds since the
349 * epoch. It can be given in local or universal time. The results will
350 * indicate whether DST is in effect at the queried time, and will give both
351 * the GMT offset for the active zone/DST rule and the opposite DST. This
352 * enables a caller to efficiently adjust for the case where an explicit
353 * DST specification mismatches what would be in effect at the time. */
355 void __secs_to_zone(long long t
, int local
, int *isdst
, long *offset
, long *oppoff
, const char **zonename
)
362 size_t alt
, i
= scan_trans(t
, local
, &alt
);
364 *isdst
= types
[6*i
+4];
365 *offset
= (int32_t)zi_read32(types
+6*i
);
366 *zonename
= (const char *)abbrevs
+ types
[6*i
+5];
367 if (oppoff
) *oppoff
= (int32_t)zi_read32(types
+6*alt
);
373 if (!__daylight
) goto std
;
375 /* FIXME: may be broken if DST changes right at year boundary?
376 * Also, this could be more efficient.*/
377 long long y
= t
/ 31556952 + 70;
378 while (__year_to_secs(y
, 0) > t
) y
--;
379 while (__year_to_secs(y
+1, 0) < t
) y
++;
381 long long t0
= rule_to_secs(r0
, y
);
382 long long t1
= rule_to_secs(r1
, y
);
389 if (t
>= t0
&& t
< t1
) goto dst
;
392 if (t
>= t1
&& t
< t0
) goto std
;
397 *offset
= -__timezone
;
398 if (oppoff
) *oppoff
= -dst_off
;
399 *zonename
= __tzname
[0];
405 if (oppoff
) *oppoff
= -__timezone
;
406 *zonename
= __tzname
[1];
410 static void __tzset()
417 weak_alias(__tzset
, tzset
);
419 const char *__tm_to_tzname(const struct tm
*tm
)
421 const void *p
= tm
->__tm_zone
;
424 if (p
!= __utc
&& p
!= __tzname
[0] && p
!= __tzname
[1] &&
425 (!zi
|| (uintptr_t)p
-(uintptr_t)abbrevs
>= abbrevs_end
- abbrevs
))