private static IDnsQuery NewQuery(DatagramPacket packet, IByteBuffer buffer)
{
int id = buffer.ReadUnsignedShort();
int flags = buffer.ReadUnsignedShort();
if (flags >> 15 == 1)
{
throw new CorruptedFrameException("not a query");
}
IDnsQuery query = new DatagramDnsQuery(
packet.Sender, packet.Recipient, id,
DnsOpCode.From((byte)(flags >> 11 & 0xf)));
query.IsRecursionDesired = (flags >> 8 & 1) == 1;
query.Z = flags >> 4 & 0x7;
return(query);
}
private static IDnsResponse NewResponse(DatagramPacket packet, IByteBuffer buffer)
{
int id = buffer.ReadUnsignedShort();
int flags = buffer.ReadUnsignedShort();
if (flags >> 15 == 0)
{
throw new CorruptedFrameException("not a response");
}
IDnsResponse response = new DatagramDnsResponse(
packet.Sender,
packet.Recipient,
id,
DnsOpCode.From((byte)(flags >> 1 & 0xf)),
DnsResponseCode.From((byte)(flags & 0xf)));
return(response);
}
protected virtual IDnsResponse NewResponse(T sender, T recipient, int id,
DnsOpCode opCode, DnsResponseCode responseCode) => new DefaultDnsResponse(id, opCode, responseCode);