store complete cookie when receiving from downstream. Add function through search through an edns_option list

util/data/msgparse.h

@@ -254,6 +254,15 @@ struct edns_option {
 	uint8_t* opt_data;
 };
 
+
+/**
+ * Search through an EDNS list to find if the specified option.
+ * @param option: The EDNS list which we search in
+ * @param code: the option code that we search for
+ * @return: returns the option if it is there, and NULL when it is not
+ */
+struct edns_option* edns_list_get_option(struct edns_option* option, uint16_t code);
+
 /**
  * Obtain size in the packet of an rr type, that is before dname type.
  * Do TYPE_DNAME, and type STR, yourself. Gives size for most regular types.