+/**
+ * Test if visitor's IP is authorized to upload.
+ * @param $ip IP to be challenged
+ * @return true if IP is authorized, false otherwise.
+ */
+function jirafeau_challenge_upload_ip ($cfg, $ip)
+{
+ if (count ($cfg['upload_ip']) == 0)
+ return true;
+ forEach ($cfg['upload_ip'] as $i)
+ {
+ if ($i == $ip)
+ return true;
+ // CIDR test for IPv4 only.
+ if (strpos ($i, '/') !== false)
+ {
+ list ($subnet, $mask) = explode('/', $i);
+ if ((ip2long ($ip) & ~((1 << (32 - $mask)) - 1) ) == ip2long ($subnet))
+ return true;
+ }
+ }
+ return false;
+}
+