def serve(self): """Start serving requests""" sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) sock.bind(("", self.port)) while not self.done: data, address = sock.recvfrom(65565) message = Message.from_bytes(data) rd = message.header.rd rcode = 0 aa = 1 self.log("REQUEST RECIEVED:", address) answers, authorities, additionals = self.zone_resolution(message.questions) if answers == []: if authorities == [] and additionals == []: self.log("\tZONE RESOLUTION FAILED") answers = self.consult_cache(message.questions) if answers == []: self.log("\tCACHE LOOKUP FAILED") rcode = 3 else: aa = 0 if rcode == 3 and rd == 1: rcode = 0 self.log("\tCALLING RESOLVER") resolver = Resolver(5, True, 0) resolver.rd = 0 resolver.rootip = "198.41.0.4" for q in message.questions: self.log("\t\tRESOLVING:", q.qname) hostname, namelist, iplist = resolver.gethostbyname(str(q.qname)) if hostname == str(q.qname): for ip in iplist: answers.append(ResourceRecord(q.qname, Type.A, Class.IN, self.ttl, ARecordData(ip))) for n in namelist: answers.append(ResourceRecord(q.qname, Type.CNAME, Class.IN, self.ttl, CNAMERecordData(n))) self.log("SENDING RESPONSE:", rcode, "\n") mess = self.build_message(message.header.ident, rd, aa, rcode, message.questions, answers, authorities, additionals) sock.sendto(mess.to_bytes(), address)