private static ZeroconfRecord DnsToZeroconf(DnsMessage message)
{
if (!message.IsResponse)
return null;
var zr = new ZeroconfRecord();
var ptr = message.Records.OfType<PtrRecord>().FirstOrDefault();
if (ptr != null)
zr.Name = ptr.DomainNamePointer.Split('.')[0];
var hst = message.Records.OfType<HostAddressRecord>().FirstOrDefault();
if (hst != null)
{
zr.Host = hst.ResourceName.Split('.')[0];
zr.IPAddress = hst.IPAddress;
}
var srv = message.Records.OfType<SrvRecord>().FirstOrDefault();
if (srv != null)
zr.Port = srv.Port.ToString();
return zr;
}
private static DnsMessage ReadDnsMessage(IDataReader dataReader)
{
var stringReader = new DnsStringReader(dataReader, dataReader.UnconsumedBufferLength);
var msg = new DnsMessage
{
QueryIdentifier = dataReader.ReadUInt16(),
Flags = dataReader.ReadUInt16(),
};
var qCount = dataReader.ReadUInt16();
var aCount = dataReader.ReadUInt16();
var nsCount = dataReader.ReadUInt16();
var arCount = dataReader.ReadUInt16();
var nonQuestions = aCount + nsCount + arCount;
for (var i = 0; i < qCount; i++)
msg.Records.Add(new QuestionRecord
{
ResourceName = stringReader.ReadString(),
QuestionType = dataReader.ReadUInt16(),
Class = dataReader.ReadUInt16()
});
for (var i = 0; i < nonQuestions; i++)
{
var resName = stringReader.ReadString();
var resType = dataReader.ReadUInt16();
var resClass = dataReader.ReadUInt16();
var ttl = dataReader.ReadUInt32();
var resLength = dataReader.ReadUInt16();
var remaining = dataReader.UnconsumedBufferLength;
ResourceRecord rec;
switch (resType)
{
case 1: // A,
rec = new HostAddressRecord
{
IPAddress = string.Format("{0}.{1}.{2}.{3}",
dataReader.ReadByte(), dataReader.ReadByte(),
dataReader.ReadByte(), dataReader.ReadByte())
};
break;
case 12: // PTR
rec = new PtrRecord
{
DomainNamePointer = stringReader.ReadString(resLength)
};
break;
case 16: // TXT
rec = new TxtRecord
{
TextRData = stringReader.ReadString(resLength)
};
break;
case 33: // SRV
rec = new SrvRecord
{
Priority = dataReader.ReadUInt16(),
Weight = dataReader.ReadUInt16(),
Port = dataReader.ReadUInt16(),
Target = stringReader.ReadString(resLength)
};
break;
default:
rec = new UnknownDnsRecord
{
ResourceType = resType
};
break;
}
rec.ResourceName = resName;
rec.Class = resClass;
rec.Ttl = ttl;
msg.Records.Add(rec);
var remainingResourceBytes = (int)(resLength - (remaining - dataReader.UnconsumedBufferLength));
if (remainingResourceBytes < 0)
{
Debug.WriteLine("error reading resource - reached into next record");
return msg;
}
if (remainingResourceBytes > 0)
dataReader.ReadBuffer((uint)remainingResourceBytes);
}
return msg;
}
