/// <summary>
/// Function that processes the incoming data after an async callback returned.
/// </summary>
/// <param name="endpoint">The endpoint the data came from</param>
/// <param name="Data">The dns packet data</param>
/// <returns></returns>
private bool DNSRequestHandler(EndPoint endpoint, byte[] Data)
{
//take out the headers, decide where to send it into the processor.
if (Processor.IsDNSRequest(Data))
{
DNSPacket packet = DNSPacket.RawToPacket(Data);
if (packet.Type == DNSPacket.PacketType.Request)
{
string lookupData = Encoding.ASCII.GetString(packet.Data, 0, packet.Length);
switch (packet.Lookup)
{
case DNSPacket.LookupType.Name:
return(SendResponse(endpoint, packet.Lookup, Processor.LookupByName(lookupData.Split('.').Reverse().ToArray())));
case DNSPacket.LookupType.ARPA:
return(SendResponse(endpoint, packet.Lookup, Processor.LookupByIp(lookupData)));
}
}
else
{
throw new DNSException(packet, "Received a Response package while expecting only Request packages.");
}
}
return(false);
}
/// <summary>
/// Connects with the provided DNS Server and retrieves the DNS name by looking up the given IP.
/// </summary>
/// <param name="ipadd">the ip address you want a DNS name for.</param>
/// <returns></returns>
public string RetrieveDNSName(string ipadd)
{
Connect();
DNSPacket packet = new DNSPacket
{
Type = DNSPacket.PacketType.Request,
Lookup = DNSPacket.LookupType.ARPA,
Data = Encoding.ASCII.GetBytes(ipadd)
};
packet.Length = packet.Data.Length;
byte[] raw = DNSPacket.PacketToRaw(packet);
Client.Send(raw, packet.Length + 3);
IPEndPoint ipep = new IPEndPoint(IPAddress.Parse(Address), 51);
byte[] answer = Client.Receive(ref ipep);
string responseData;
if (answer.Length != 0 && ipep.Address.ToString().Equals(Address))
{
//checks if the response came from the DNS server
DNSPacket response = DNSPacket.RawToPacket(answer);
if (response.Type == DNSPacket.PacketType.Response && response.Lookup == DNSPacket.LookupType.ARPA)
{
responseData = Encoding.ASCII.GetString(response.Data, 0, response.Length);
}
else
{
throw new DNSException(response, "Expected a Response and Name type, got something else.");
}
}
else
{
throw new DNSException(null, "Received empty response or the response came from the wrong host.");
}
Disconnect();
return(responseData);
}