public IDnsRecord DecodeRecord(IByteBuffer inputBuffer)
{
int startOffset = inputBuffer.ReaderIndex;
string name = DecodeName(inputBuffer);
int endOffset = inputBuffer.WriterIndex;
if (endOffset - startOffset < 10)
{
inputBuffer.SetReaderIndex(startOffset);
return(null);
}
DnsRecordType type = DnsRecordType.From(inputBuffer.ReadUnsignedShort());
var recordClass = (DnsRecordClass)inputBuffer.ReadUnsignedShort();
long ttl = inputBuffer.ReadUnsignedInt();
int length = inputBuffer.ReadUnsignedShort();
int offset = inputBuffer.ReaderIndex;
if (endOffset - offset < length)
{
inputBuffer.SetReaderIndex(startOffset);
return(null);
}
IDnsRecord record = DecodeRecord(name, type, recordClass, ttl, inputBuffer, offset, length);
inputBuffer.SetReaderIndex(offset + length);
return(record);
}
public IDnsQuestion DecodeQuestion(IByteBuffer inputBuffer)
{
string name = DecodeName(inputBuffer);
DnsRecordType type = DnsRecordType.From(inputBuffer.ReadUnsignedShort());
var recordClass = (DnsRecordClass)inputBuffer.ReadUnsignedShort();
return(new DefaultDnsQuestion(name, type, recordClass));
}
private async Task <IDnsResponse> WriteResponse(TransportMessage message)
{
var response = GetDnsResponse(message);
var dnsQuestion = GetDnsQuestion(message);
var ipAddr = GetIpAddr(message);
if (response != null && dnsQuestion != null)
{
if (ipAddr != null)
{
var buf = Unpooled.WrappedBuffer(ipAddr.GetAddressBytes());
response.AddRecord(DnsSection.ANSWER,
new DefaultDnsRawRecord(dnsQuestion.Name, DnsRecordType.A, 100, buf));
}
else
{
var dnsMessage = await GetDnsMessage(dnsQuestion.Name, dnsQuestion.Type);
if (dnsMessage != null)
{
foreach (var dnsRecord in dnsMessage.AnswerRecords)
{
var aRecord = dnsRecord as ARecord;
var buf = Unpooled.Buffer();
if (dnsRecord.RecordType == RecordType.Ptr)
{
var ptrRecord = dnsRecord as PtrRecord;
response.AddRecord(DnsSection.ANSWER,
new DefaultDnsPtrRecord(ptrRecord.Name.ToString(),
(DnsRecordClass)(int)ptrRecord.RecordClass, ptrRecord.TimeToLive,
ptrRecord.PointerDomainName.ToString()));
}
if (aRecord != null)
{
buf = Unpooled.WrappedBuffer(aRecord.Address.GetAddressBytes());
response.AddRecord(DnsSection.ANSWER,
new DefaultDnsRawRecord(dnsQuestion.Name,
DnsRecordType.From((int)dnsRecord.RecordType),
(DnsRecordClass)(int)aRecord.RecordClass, dnsRecord.TimeToLive, buf));
}
}
}
}
}
return(response);
}