utils: add lxc_safe_long_long()

src/lxc/utils.c

@@ -2003,6 +2003,26 @@ int lxc_safe_long(const char *numstr, long int *converted)
 	return 0;
 }
 
+int lxc_safe_long_long(const char *numstr, long long int *converted)
+{
+	char *err = NULL;
+	signed long long int sli;
+
+	errno = 0;
+	sli = strtoll(numstr, &err, 0);
+	if (errno == ERANGE && (sli == LLONG_MAX || sli == LLONG_MIN))
+		return -ERANGE;
+
+	if (errno != 0 && sli == 0)
+		return -EINVAL;
+
+	if (err == numstr || *err != '\0')
+		return -EINVAL;
+
+	*converted = sli;
+	return 0;
+}
+
 int lxc_switch_uid_gid(uid_t uid, gid_t gid)
 {
 	if (setgid(gid) < 0) {

src/lxc/utils.h

@@ -419,6 +419,7 @@ extern bool task_blocking_signal(pid_t pid, int signal);
 extern int lxc_safe_uint(const char *numstr, unsigned int *converted);
 extern int lxc_safe_int(const char *numstr, int *converted);
 extern int lxc_safe_long(const char *numstr, long int *converted);
+extern int lxc_safe_long_long(const char *numstr, long long int *converted);
 extern int lxc_safe_ulong(const char *numstr, unsigned long *converted);
 
 /* Switch to a new uid and gid. */