示例#1
0
        /// <summary>
        /// Construct a Response object from the supplied byte array
        /// </summary>
        /// <param name="message">a byte array returned from a DNS server query</param>
        internal Response(byte[] message)
        {
            // the bit flags are in bytes 2 and 3
            byte flags1 = message[2];
            byte flags2 = message[3];

            // get return code from lowest 4 bits of byte 3
            int returnCode = flags2 & 15;

            // if its in the reserved section, set to other
            if (returnCode > 6) returnCode = 6;
            _returnCode = (ReturnCode)returnCode;

            // other bit flags
            _authoritativeAnswer = ((flags1 & 4) != 0);
            _recursionAvailable = ((flags2 & 128) != 0);
            _truncated = ((flags1 & 2) != 0);

            // create the arrays of response objects
            _questions = new Question[GetShort(message, 4)];
            _answers = new Answer[GetShort(message, 6)];
            _nameServers = new NameServer[GetShort(message, 8)];
            _additionalRecords = new AdditionalRecord[GetShort(message, 10)];

            // need a pointer to do this, position just after the header
            Pointer pointer = new Pointer(message, 12);

            // and now populate them, they always follow this order
            for (int index = 0; index < _questions.Length; index++)
            {
                try
                {
                    // try to build a quesion from the response
                    _questions[index] = new Question(pointer);
                }
                catch (Exception ex)
                {
                    // something grim has happened, we can't continue
                    throw new InvalidResponseException(ex);
                }
            }
            for (int index = 0; index < _answers.Length; index++)
            {
                _answers[index] = new Answer(pointer);
            }
            for (int index = 0; index < _nameServers.Length; index++)
            {
                _nameServers[index] = new NameServer(pointer);
            }
            for (int index = 0; index < _additionalRecords.Length; index++)
            {
                _additionalRecords[index] = new AdditionalRecord(pointer);
            }
        }
示例#2
0
        /// <summary>
        /// Adds a question to the request to be sent to the DNS server.
        /// </summary>
        /// <param name="question">The question to add to the request</param>
        public void AddQuestion(Question question)
        {
            // abandon if null
            if (question == null) throw new ArgumentNullException("question");

            // add this question to our collection
            _questions.Add(question);
        }