cutils: Fix qemu_strtosz() & friends to reject non-finite sizes

qemu_strtosz() & friends reject NaNs, but happily accept infinities.
They shouldn't. Fix that.

The fix makes use of qemu_strtod_finite(). To avoid ugly casts,
change the @end parameter of qemu_strtosz() & friends from char **
to const char **.

Also, add two test cases, testing that "inf" and "NaN" are properly
rejected. While at it, also fixup the function documentation.

Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20181121164421.20780-3-david@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

1 files changed, 8 insertions, 10 deletions

diff --git a/util/cutils.c b/util/cutils.c
index ec0a401..e098deb 100644
--- a/util/cutils.c
+++ b/util/cutils.c
@@ -203,23 +203,21 @@ static int64_t suffix_mul(char suffix, int64_t unit)
 /*
  * Convert string to bytes, allowing either B/b for bytes, K/k for KB,
  * M/m for MB, G/g for GB or T/t for TB. End pointer will be returned
- * in *end, if not NULL. Return -ERANGE on overflow, Return -EINVAL on
+ * in *end, if not NULL. Return -ERANGE on overflow, and -EINVAL on
  * other error.
  */
-static int do_strtosz(const char *nptr, char **end,
+static int do_strtosz(const char *nptr, const char **end,
                       const char default_suffix, int64_t unit,
                       uint64_t *result)
 {
     int retval;
-    char *endptr;
+    const char *endptr;
     unsigned char c;
     int mul_required = 0;
     double val, mul, integral, fraction;
 
-    errno = 0;
-    val = strtod(nptr, &endptr);
-    if (isnan(val) || endptr == nptr || errno != 0) {
-        retval = -EINVAL;
+    retval = qemu_strtod_finite(nptr, &endptr, &val);
+    if (retval) {
         goto out;
     }
     fraction = modf(val, &integral);
@@ -259,17 +257,17 @@ out:
     return retval;
 }
 
-int qemu_strtosz(const char *nptr, char **end, uint64_t *result)
+int qemu_strtosz(const char *nptr, const char **end, uint64_t *result)
 {
     return do_strtosz(nptr, end, 'B', 1024, result);
 }
 
-int qemu_strtosz_MiB(const char *nptr, char **end, uint64_t *result)
+int qemu_strtosz_MiB(const char *nptr, const char **end, uint64_t *result)
 {
     return do_strtosz(nptr, end, 'M', 1024, result);
 }
 
-int qemu_strtosz_metric(const char *nptr, char **end, uint64_t *result)
+int qemu_strtosz_metric(const char *nptr, const char **end, uint64_t *result)
 {
     return do_strtosz(nptr, end, 'B', 1000, result);
 }