/*
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
| |
| / /
| / NAME /
| |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
| TYPE |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
| CLASS |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
| TTL |
| |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
| RDLENGTH |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--|
| / RDATA /
| / /
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
* */
public ResourceRecordInfo ReadRecordInfo()
{
return(new ResourceRecordInfo(
_reader.ReadQuestionQueryString(), // name
(ResourceRecordType)_reader.ReadUInt16NetworkOrder(), // type
(QueryClass)_reader.ReadUInt16NetworkOrder(), // class
(int)_reader.ReadUInt32NetworkOrder(), // ttl - 32bit!!
_reader.ReadUInt16NetworkOrder())); // RDLength
}
public DnsResponseMessage GetResponseMessage(ArraySegment <byte> responseData)
{
var reader = new DnsDatagramReader(responseData);
var id = reader.ReadUInt16NetworkOrder();
var flags = reader.ReadUInt16NetworkOrder();
var questionCount = reader.ReadUInt16NetworkOrder();
var answerCount = reader.ReadUInt16NetworkOrder();
var nameServerCount = reader.ReadUInt16NetworkOrder();
var additionalCount = reader.ReadUInt16NetworkOrder();
var header = new DnsResponseHeader(id, flags, questionCount, answerCount, additionalCount, nameServerCount);
var response = new DnsResponseMessage(header, responseData.Count);
for (var questionIndex = 0; questionIndex < questionCount; questionIndex++)
{
var questionQueryString = reader.ReadQuestionQueryString();
var queryTypeValue = reader.ReadUInt16NetworkOrder();
var queryClass = reader.ReadUInt16NetworkOrder();
if (!_queryTypes.TryGetValue(queryTypeValue, out var queryType))
{
queryType = new PseudoResourceRecordType(
abbreviation: "Unknown",
value: queryTypeValue
);
}
var question = new DnsQuestion(questionQueryString, queryType, (QueryClass)queryClass);
response.AddQuestion(question);
}
for (var answerIndex = 0; answerIndex < answerCount; answerIndex++)
{
var info = ReadRecordInfo(reader);
var record = _dnsRecordFactory.GetRecord(info, reader);
response.AddAnswer(record);
}
for (var serverIndex = 0; serverIndex < nameServerCount; serverIndex++)
{
var info = ReadRecordInfo(reader);
var record = _dnsRecordFactory.GetRecord(info, reader);
response.AddAuthority(record);
}
for (var additionalIndex = 0; additionalIndex < additionalCount; additionalIndex++)
{
var info = ReadRecordInfo(reader);
var record = _dnsRecordFactory.GetRecord(info, reader);
response.AddAdditional(record);
}
return(response);
}
/// <summary>
/// Reads a <see cref="ResourceRecord"/> from this <see cref="DnsDatagramReader"/>.
/// </summary>
private ResourceRecord ReadRecordInfo(DnsDatagramReader reader)
{
var queryString = reader.ReadQuestionQueryString();
var type = reader.ReadUInt16NetworkOrder();
if (!_resourceRecordTypes.TryGetValue(type, out var resourceRecordType))
{
resourceRecordType = new PseudoResourceRecordType(
abbreviation: "Unknown - machine generated",
value: type
);
}
var queryClass = reader.ReadUInt16NetworkOrder();
var ttl = reader.ReadUInt32NetworkOrder();
var rdLength = reader.ReadUInt16NetworkOrder();
return(new ResourceRecord(
queryString, // name
resourceRecordType, // type
(QueryClass)queryClass, // class
(int)ttl, // ttl - 32bit!!
rdLength)); // RDLength
}
public virtual DnsResponseMessage GetResponseMessage(ArraySegment <byte> responseData)
{
var reader = new DnsDatagramReader(responseData);
var factory = new DnsRecordFactory(reader);
var id = reader.ReadUInt16NetworkOrder();
var flags = reader.ReadUInt16NetworkOrder();
var questionCount = reader.ReadUInt16NetworkOrder();
var answerCount = reader.ReadUInt16NetworkOrder();
var nameServerCount = reader.ReadUInt16NetworkOrder();
var additionalCount = reader.ReadUInt16NetworkOrder();
var header = new DnsResponseHeader(id, flags, questionCount, answerCount, additionalCount, nameServerCount);
var response = new DnsResponseMessage(header, responseData.Count);
for (int questionIndex = 0; questionIndex < questionCount; questionIndex++)
{
var question = new DnsQuestion(reader.ReadQuestionQueryString(), (QueryType)reader.ReadUInt16NetworkOrder(), (QueryClass)reader.ReadUInt16NetworkOrder());
response.AddQuestion(question);
}
for (int answerIndex = 0; answerIndex < answerCount; answerIndex++)
{
var info = factory.ReadRecordInfo();
var record = factory.GetRecord(info);
response.AddAnswer(record);
}
for (int serverIndex = 0; serverIndex < nameServerCount; serverIndex++)
{
var info = factory.ReadRecordInfo();
var record = factory.GetRecord(info);
response.AddAuthority(record);
}
for (int additionalIndex = 0; additionalIndex < additionalCount; additionalIndex++)
{
var info = factory.ReadRecordInfo();
var record = factory.GetRecord(info);
response.AddAdditional(record);
}
return(response);
}
