Modify tzset_r.c to handle errors

- change __tzset_r so errors end up setting the timezone to
  unnamed UTC
This commit is contained in:
Jeff Johnston 2022-04-27 15:27:00 -04:00
parent 9af21ada23
commit 2dbdf66b91
1 changed files with 48 additions and 20 deletions

View File

@ -12,8 +12,8 @@
#define TZNAME_MIN 3 /* POSIX min TZ abbr size local def */
#define TZNAME_MAX 10 /* POSIX max TZ abbr size local def */
static char __tzname_std[TZNAME_MAX + 1];
static char __tzname_dst[TZNAME_MAX + 1];
static char __tzname_std[TZNAME_MAX + 2];
static char __tzname_dst[TZNAME_MAX + 2];
static char *prev_tzenv = NULL;
void
@ -23,7 +23,9 @@ _tzset_unlocked_r (struct _reent *reent_ptr)
unsigned short hh, mm, ss, m, w, d;
int sign, n;
int i, ch;
long offset0, offset1;
__tzinfo_type *tz = __gettzinfo ();
struct __tzrule_struct default_tzrule = {'J', 0, 0, 0, 0, (time_t)0, 0L };
if ((tzenv = _getenv_r (reent_ptr, "TZ")) == NULL)
{
@ -31,6 +33,8 @@ _tzset_unlocked_r (struct _reent *reent_ptr)
_daylight = 0;
_tzname[0] = "GMT";
_tzname[1] = "GMT";
tz->__tzrule[0] = default_tzrule;
tz->__tzrule[1] = default_tzrule;
free(prev_tzenv);
prev_tzenv = NULL;
return;
@ -44,6 +48,14 @@ _tzset_unlocked_r (struct _reent *reent_ptr)
if (prev_tzenv != NULL)
strcpy (prev_tzenv, tzenv);
/* default to unnamed UTC in case of error */
_timezone = 0;
_daylight = 0;
_tzname[0] = "";
_tzname[1] = "";
tz->__tzrule[0] = default_tzrule;
tz->__tzrule[1] = default_tzrule;
/* ignore implementation-specific format specifier */
if (*tzenv == ':')
++tzenv;
@ -54,7 +66,7 @@ _tzset_unlocked_r (struct _reent *reent_ptr)
++tzenv;
/* quit if no items, too few or too many chars, or no close quote '>' */
if (sscanf (tzenv, "%10[-+0-9A-Za-z]%n", __tzname_std, &n) <= 0
if (sscanf (tzenv, "%11[-+0-9A-Za-z]%n", __tzname_std, &n) <= 0
|| n < TZNAME_MIN || TZNAME_MAX < n || '>' != tzenv[n])
return;
@ -63,7 +75,7 @@ _tzset_unlocked_r (struct _reent *reent_ptr)
else
{
/* allow POSIX unquoted alphabetic tz abbr e.g. MESZ */
if (sscanf (tzenv, "%10[A-Za-z]%n", __tzname_std, &n) <= 0
if (sscanf (tzenv, "%11[A-Za-z]%n", __tzname_std, &n) <= 0
|| n < TZNAME_MIN || TZNAME_MAX < n)
return;
}
@ -85,8 +97,7 @@ _tzset_unlocked_r (struct _reent *reent_ptr)
if (sscanf (tzenv, "%hu%n:%hu%n:%hu%n", &hh, &n, &mm, &n, &ss, &n) < 1)
return;
tz->__tzrule[0].offset = sign * (ss + SECSPERMIN * mm + SECSPERHOUR * hh);
_tzname[0] = __tzname_std;
offset0 = sign * (ss + SECSPERMIN * mm + SECSPERHOUR * hh);
tzenv += n;
/* allow POSIX angle bracket < > quoted signed alphanumeric tz abbr e.g. <MESZ+0330> */
@ -95,12 +106,16 @@ _tzset_unlocked_r (struct _reent *reent_ptr)
++tzenv;
/* quit if no items, too few or too many chars, or no close quote '>' */
if (sscanf (tzenv, "%10[-+0-9A-Za-z]%n", __tzname_dst, &n) <= 0
|| n < TZNAME_MIN || TZNAME_MAX < n || '>' != tzenv[n])
if (sscanf (tzenv, "%11[-+0-9A-Za-z]%n", __tzname_dst, &n) <= 0 && tzenv[0] == '>')
{ /* No dst */
_tzname[0] = __tzname_std;
_tzname[1] = _tzname[0];
_timezone = tz->__tzrule[0].offset;
_daylight = 0;
tz->__tzrule[0].offset = offset0;
_timezone = offset0;
return;
}
else if (n < TZNAME_MIN || TZNAME_MAX < n || '>' != tzenv[n])
{ /* error */
return;
}
@ -109,17 +124,20 @@ _tzset_unlocked_r (struct _reent *reent_ptr)
else
{
/* allow POSIX unquoted alphabetic tz abbr e.g. MESZ */
if (sscanf (tzenv, "%10[A-Za-z]%n", __tzname_dst, &n) <= 0
|| n < TZNAME_MIN || TZNAME_MAX < n)
if (sscanf (tzenv, "%11[A-Za-z]%n", __tzname_dst, &n) <= 0)
{ /* No dst */
_tzname[0] = __tzname_std;
_tzname[1] = _tzname[0];
_timezone = tz->__tzrule[0].offset;
_daylight = 0;
tz->__tzrule[0].offset = offset0;
_timezone = offset0;
return;
}
else if (n < TZNAME_MIN || TZNAME_MAX < n)
{ /* error */
return;
}
}
_tzname[1] = __tzname_dst;
tzenv += n;
/* otherwise we have a dst name, look for the offset */
@ -138,9 +156,9 @@ _tzset_unlocked_r (struct _reent *reent_ptr)
n = 0;
if (sscanf (tzenv, "%hu%n:%hu%n:%hu%n", &hh, &n, &mm, &n, &ss, &n) <= 0)
tz->__tzrule[1].offset = tz->__tzrule[0].offset - 3600;
offset1 = offset0 - 3600;
else
tz->__tzrule[1].offset = sign * (ss + SECSPERMIN * mm + SECSPERHOUR * hh);
offset1 = sign * (ss + SECSPERMIN * mm + SECSPERHOUR * hh);
tzenv += n;
@ -211,13 +229,23 @@ _tzset_unlocked_r (struct _reent *reent_ptr)
n = 0;
if (*tzenv == '/')
sscanf (tzenv, "/%hu%n:%hu%n:%hu%n", &hh, &n, &mm, &n, &ss, &n);
if (sscanf (tzenv, "/%hu%n:%hu%n:%hu%n", &hh, &n, &mm, &n, &ss, &n) <= 0)
{
/* error in time format, restore tz rules to default and return */
tz->__tzrule[0] = default_tzrule;
tz->__tzrule[1] = default_tzrule;
return;
}
tz->__tzrule[i].s = ss + SECSPERMIN * mm + SECSPERHOUR * hh;
tzenv += n;
}
tz->__tzrule[0].offset = offset0;
tz->__tzrule[1].offset = offset1;
_tzname[0] = __tzname_std;
_tzname[1] = __tzname_dst;
__tzcalc_limits (tz->__tzyear);
_timezone = tz->__tzrule[0].offset;
_daylight = tz->__tzrule[0].offset != tz->__tzrule[1].offset;