/* * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ | | | / / | / NAME / | | +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ | TYPE | +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ | CLASS | +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ | TTL | | | +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ | RDLENGTH | +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| | / RDATA / | / / +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ */ public BaseResourceRecordInfo ReadRecordInfo(ArraySegment <byte> data) { IDnsString domainName = _reader.ReadQuestionQueryString(data); // domain name ResourceRecordType recordType = (ResourceRecordType)_reader.ReadUInt16NetworkOrder(data); // record type QueryClass queryClass = (QueryClass)_reader.ReadUInt16NetworkOrder(data); // query class int timeToLive = (int)_reader.ReadUInt32NetworkOrder(data); // ttl - 32bit!! int rawDataLength = _reader.ReadUInt16NetworkOrder(data); // RDLength return(new BaseResourceRecordInfo( recordType, // record type queryClass, // query class timeToLive, // ttl - 32bit!! rawDataLength, // RDLength domainName // domain name )); }
/// <summary> Constructs the response object based upon the data received from the DNS server. </summary> /// <param name="responseData">The data (byte[]) from the DNS server.</param> /// <returns>Response message object.</returns> public DnsResponseMessage ProcessResponse(ArraySegment <byte> responseData) { IDnsRecordFactory factory = new DnsRecordFactory(reader); /* * From index 0 till 11 bytes in the responseData array, we have the header items. */ ushort id = reader.ReadUInt16NetworkOrder(responseData); ushort flags = reader.ReadUInt16NetworkOrder(responseData); ushort questionCount = reader.ReadUInt16NetworkOrder(responseData); ushort answerCount = reader.ReadUInt16NetworkOrder(responseData); ushort nameServerCount = reader.ReadUInt16NetworkOrder(responseData); ushort additionalCount = reader.ReadUInt16NetworkOrder(responseData); /* * We have got above data, now build the response header. */ DnsResponseHeader header = new DnsResponseHeader(id, flags, questionCount, answerCount, additionalCount, nameServerCount); DnsResponseMessage response = new DnsResponseMessage(header, responseData.Count); /* * Next item in the response data is question that we sent to the DNS server which the server has copied onto the response message. */ for (int questionIndex = 0; questionIndex < questionCount; questionIndex++) { IDnsString questionString = reader.ReadQuestionQueryString(responseData); DnsQuestion question = new DnsQuestion(questionString, (QueryType)reader.ReadUInt16NetworkOrder(responseData), (QueryClass)reader.ReadUInt16NetworkOrder(responseData)); response.AddQuestion(question); } for (int answerIndex = 0; answerIndex < answerCount; answerIndex++) { BaseResourceRecordInfo info = factory.ReadRecordInfo(responseData); DnsResourceRecord record = factory.GetRecord(info, responseData); response.AddAnswer(record); } for (int serverIndex = 0; serverIndex < nameServerCount; serverIndex++) { BaseResourceRecordInfo info = factory.ReadRecordInfo(responseData); DnsResourceRecord record = factory.GetRecord(info, responseData); response.AddAuthority(record); } for (int additionalIndex = 0; additionalIndex < additionalCount; additionalIndex++) { BaseResourceRecordInfo info = factory.ReadRecordInfo(responseData); DnsResourceRecord record = factory.GetRecord(info, responseData); response.AddAdditional(record); } return(response); }