/// <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);
}
public void ReadRecordInfo_should_return_BaseResourceRecordInfo_from_responseMessage()
{
// Arrange.
const string query = "www.msn.com";
const string queryRoot = query + ".";
const ushort recordType = 1; // A - Host Address.
const ushort queryClass = 1; // IN
const int timeToLive = 1000;
const int rawDataLen = 10;
ArraySegment <byte> responseData = GetSampleData(ResponseDataSampleFile.QuestionAndAnswerQuery);
mockReader.Setup(r => r.ReadQuestionQueryString(responseData))
.Returns(new DnsString(query, queryRoot));
mockReader.SetupSequence(r => r.ReadUInt16NetworkOrder(responseData))
.Returns(recordType)
.Returns(queryClass)
.Returns(rawDataLen);
mockReader.Setup(r => r.ReadUInt32NetworkOrder(responseData))
.Returns(timeToLive);
IDnsRecordFactory factory = new DnsRecordFactory(mockReader.Object);
// Act.
BaseResourceRecordInfo recordInfo = factory.ReadRecordInfo(responseData);
// Assert.
// no need to check id recordInfo is null because we are already asserting on its properties.
Assert.AreEqual(queryRoot, recordInfo.DomainName.ToString());
Assert.AreEqual(recordType, (int)recordInfo.RecordType);
Assert.AreEqual(queryClass, (int)recordInfo.RecordClass);
Assert.AreEqual(rawDataLen, recordInfo.RawDataLength);
Assert.AreEqual(timeToLive, recordInfo.TimeToLive);
}