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authorDaniel P. Berrange <berrange@redhat.com>2017-12-22 12:46:23 +0000
committerDaniel P. Berrangé <berrange@redhat.com>2018-03-13 18:06:05 +0000
commit473a2a331ee382703f7ca0067ba2545350cfa06c (patch)
tree4c1eef0279b4a65ff55c20ec0b39d6c09fc8aefa /util
parent63bab2b69688dee0ddadff7449143830e59567cd (diff)
cutils: add qemu_strtoi & qemu_strtoui parsers for int/unsigned int types
There are qemu_strtoNN functions for various sized integers. This adds two more for plain int & unsigned int types, with suitable range checking. Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Diffstat (limited to 'util')
-rw-r--r--util/cutils.c109
1 files changed, 109 insertions, 0 deletions
diff --git a/util/cutils.c b/util/cutils.c
index b33ede83d1..0de69e6db4 100644
--- a/util/cutils.c
+++ b/util/cutils.c
@@ -298,6 +298,115 @@ static int check_strtox_error(const char *nptr, char *ep,
}
/**
+ * Convert string @nptr to an integer, and store it in @result.
+ *
+ * This is a wrapper around strtol() that is harder to misuse.
+ * Semantics of @nptr, @endptr, @base match strtol() with differences
+ * noted below.
+ *
+ * @nptr may be null, and no conversion is performed then.
+ *
+ * If no conversion is performed, store @nptr in *@endptr and return
+ * -EINVAL.
+ *
+ * If @endptr is null, and the string isn't fully converted, return
+ * -EINVAL. This is the case when the pointer that would be stored in
+ * a non-null @endptr points to a character other than '\0'.
+ *
+ * If the conversion overflows @result, store INT_MAX in @result,
+ * and return -ERANGE.
+ *
+ * If the conversion underflows @result, store INT_MIN in @result,
+ * and return -ERANGE.
+ *
+ * Else store the converted value in @result, and return zero.
+ */
+int qemu_strtoi(const char *nptr, const char **endptr, int base,
+ int *result)
+{
+ char *ep;
+ long long lresult;
+
+ if (!nptr) {
+ if (endptr) {
+ *endptr = nptr;
+ }
+ return -EINVAL;
+ }
+
+ errno = 0;
+ lresult = strtoll(nptr, &ep, base);
+ if (lresult < INT_MIN) {
+ *result = INT_MIN;
+ errno = ERANGE;
+ } else if (lresult > INT_MAX) {
+ *result = INT_MAX;
+ errno = ERANGE;
+ } else {
+ *result = lresult;
+ }
+ return check_strtox_error(nptr, ep, endptr, errno);
+}
+
+/**
+ * Convert string @nptr to an unsigned integer, and store it in @result.
+ *
+ * This is a wrapper around strtoul() that is harder to misuse.
+ * Semantics of @nptr, @endptr, @base match strtoul() with differences
+ * noted below.
+ *
+ * @nptr may be null, and no conversion is performed then.
+ *
+ * If no conversion is performed, store @nptr in *@endptr and return
+ * -EINVAL.
+ *
+ * If @endptr is null, and the string isn't fully converted, return
+ * -EINVAL. This is the case when the pointer that would be stored in
+ * a non-null @endptr points to a character other than '\0'.
+ *
+ * If the conversion overflows @result, store UINT_MAX in @result,
+ * and return -ERANGE.
+ *
+ * Else store the converted value in @result, and return zero.
+ *
+ * Note that a number with a leading minus sign gets converted without
+ * the minus sign, checked for overflow (see above), then negated (in
+ * @result's type). This is exactly how strtoul() works.
+ */
+int qemu_strtoui(const char *nptr, const char **endptr, int base,
+ unsigned int *result)
+{
+ char *ep;
+ long long lresult;
+
+ if (!nptr) {
+ if (endptr) {
+ *endptr = nptr;
+ }
+ return -EINVAL;
+ }
+
+ errno = 0;
+ lresult = strtoull(nptr, &ep, base);
+
+ /* Windows returns 1 for negative out-of-range values. */
+ if (errno == ERANGE) {
+ *result = -1;
+ } else {
+ if (lresult > UINT_MAX) {
+ *result = UINT_MAX;
+ errno = ERANGE;
+ } else if (lresult < INT_MIN) {
+ *result = UINT_MAX;
+ errno = ERANGE;
+ } else {
+ *result = lresult;
+ }
+ }
+ return check_strtox_error(nptr, ep, endptr, errno);
+}
+
+/**
* Convert string @nptr to a long integer, and store it in @result.
*
* This is a wrapper around strtol() that is harder to misuse.