2005-10-14 Ulrich Drepper <drepper@redhat.com>
+ [BZ #1460]
+ * time/asctime.c (asctime_internal): New function, derived from
+ asctime_r. Takes additional parameter which is the buffer length.
+ Use snprintf instead sprintf, if it overflows, fail.
+ (asctime_r): Call asctime_internal with 26 as buffer length.
+ (asctime): Call asctime_internal with length of internal buffer.
+ * time/Makefile (tests): Add bug-asctime_r.
+ * time/bug-asctime_r.c: New file.
+
[BZ #1459]
* time/asctime.c (__asctime_r): Check for tm_year computation to
overflow and fail in this case.
static const char format[] = "%.3s %.3s%3d %.2d:%.2d:%.2d %d\n";
static char result[ 3+1+ 3+1+20+1+20+1+20+1+20+1+20+1 + 1];
-/* Returns a string of the form "Day Mon dd hh:mm:ss yyyy\n"
- which is the representation of TP in that form. */
-char *
-asctime (const struct tm *tp)
-{
- return __asctime_r (tp, result);
-}
-libc_hidden_def (asctime)
-char *
-__asctime_r (const struct tm *tp, char *buf)
+static char *
+asctime_internal (const struct tm *tp, char *buf, size_t buflen)
{
if (tp == NULL)
{
a buffer size would be passed. */
if (__builtin_expect (tp->tm_year > INT_MAX - 1900, 0))
{
+ eoverflow:
__set_errno (EOVERFLOW);
return NULL;
}
- if (sprintf (buf, format,
- (tp->tm_wday < 0 || tp->tm_wday >= 7 ?
- "???" : ab_day_name (tp->tm_wday)),
- (tp->tm_mon < 0 || tp->tm_mon >= 12 ?
- "???" : ab_month_name (tp->tm_mon)),
- tp->tm_mday, tp->tm_hour, tp->tm_min,
- tp->tm_sec, 1900 + tp->tm_year) < 0)
+ int n = snprintf (buf, buflen, format,
+ (tp->tm_wday < 0 || tp->tm_wday >= 7 ?
+ "???" : ab_day_name (tp->tm_wday)),
+ (tp->tm_mon < 0 || tp->tm_mon >= 12 ?
+ "???" : ab_month_name (tp->tm_mon)),
+ tp->tm_mday, tp->tm_hour, tp->tm_min,
+ tp->tm_sec, 1900 + tp->tm_year);
+ if (n < 0)
return NULL;
+ if (n >= buflen)
+ goto eoverflow;
return buf;
}
+
+
+/* Like asctime, but write result to the user supplied buffer. The
+ buffer is only guaranteed to be 26 bytes in length. */
+char *
+__asctime_r (const struct tm *tp, char *buf)
+{
+ return asctime_internal (tp, buf, 26);
+}
weak_alias (__asctime_r, asctime_r)
+
+
+/* Returns a string of the form "Day Mon dd hh:mm:ss yyyy\n"
+ which is the representation of TP in that form. */
+char *
+asctime (const struct tm *tp)
+{
+ return asctime_internal (tp, result, sizeof (result));
+}
+libc_hidden_def (asctime)
--- /dev/null
+#include <errno.h>
+#include <limits.h>
+#include <stdio.h>
+#include <time.h>
+
+
+static int
+do_test (void)
+{
+ int result = 0;
+ time_t t = time (NULL);
+ struct tm *tp = localtime (&t);
+ tp->tm_year = 10000 - 1900;
+ char buf[1000];
+ errno = 0;
+ char *s = asctime_r (tp, buf);
+ if (s != NULL || errno != EOVERFLOW)
+ {
+ puts ("asctime_r did not fail correctly");
+ result = 1;
+ }
+ return result;
+}
+
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"