protected override Response SendRequest(Request request)
{
// RFC1035 max. size of a UDP datagram is 512 bytes
byte[] responseMessage = new byte[512];
for (int intAttempts = 0; intAttempts < Options.RetryCount; intAttempts++)
{
using (var datagramSocket = m_datagramSocketFactory.CreateDatagramSocket(Options.Timeout))
{
try
{
var address = IPAddress.Parse(DnsServerEndpoint.Address.ToString());
var endpoint = new IPEndpoint(address, (ushort)DnsServerEndpoint.Port);
datagramSocket.SendTo(request.Data, endpoint);
int intReceived = datagramSocket.Receive(responseMessage);
byte[] data = new byte[intReceived];
Array.Copy(responseMessage, data, intReceived);
Response response = new Response(DnsServerEndpoint, data);
CacheResponse(response);
return response;
}
catch (Exception/*SocketException*/)
{
continue;
}
finally
{
IncrementSequenceNumber();
}
}
}
Response responseTimeout = new Response();
responseTimeout.Error = "Timeout Error";
return responseTimeout;
}
protected override Response SendRequest(Request request)
{
//System.Diagnostics.Stopwatch sw = new System.Diagnostics.Stopwatch();
//sw.Start();
byte[] responseMessage = new byte[512];
for (int intAttempts = 0; intAttempts < Options.RetryCount; intAttempts++)
{
using (var streamSocket = m_streamSocketFactory.CreateStreamSocket(Options.Timeout))
{
try
{
var result = streamSocket.BeginConnect(DnsServerEndpoint.Address, DnsServerEndpoint.Port, null, null);
var success = result.AsyncWaitHandle.WaitOne(Options.Timeout);
if (!success || !streamSocket.Connected)
{
continue;
}
var sendStream = streamSocket.GetSendStream();
byte[] data = request.Data;
sendStream.WriteByte((byte)((data.Length >> 8) & 0xff));
sendStream.WriteByte((byte)(data.Length & 0xff));
sendStream.Write(data, 0, data.Length);
sendStream.Flush();
var receiveStream = streamSocket.GetReceiveStream();
Response TransferResponse = new Response();
int intSoa = 0;
int intMessageSize = 0;
//Debug.WriteLine("Sending "+ (request.Length+2) + " bytes in "+ sw.ElapsedMilliseconds+" mS");
while (true)
{
int intLength = receiveStream.ReadByte() << 8 | receiveStream.ReadByte();
if (intLength <= 0)
{
throw new Exception/*SocketException*/(); // next try
}
intMessageSize += intLength;
data = new byte[intLength];
receiveStream.Read(data, 0, intLength);
Response response = new Response(DnsServerEndpoint, data);
//Debug.WriteLine("Received "+ (intLength+2)+" bytes in "+sw.ElapsedMilliseconds +" mS");
if (response.header.RCODE != RCode.NoError)
return response;
if (response.Questions[0].QType != QType.AXFR)
{
CacheResponse(response);
return response;
}
// Zone transfer!!
if (TransferResponse.Questions.Count == 0)
TransferResponse.Questions.AddRange(response.Questions);
TransferResponse.Answers.AddRange(response.Answers);
TransferResponse.Authorities.AddRange(response.Authorities);
TransferResponse.Additionals.AddRange(response.Additionals);
if (response.Answers[0].Type == RecordType.SOA)
intSoa++;
if (intSoa == 2)
{
TransferResponse.header.QDCOUNT = (ushort)TransferResponse.Questions.Count;
TransferResponse.header.ANCOUNT = (ushort)TransferResponse.Answers.Count;
TransferResponse.header.NSCOUNT = (ushort)TransferResponse.Authorities.Count;
TransferResponse.header.ARCOUNT = (ushort)TransferResponse.Additionals.Count;
TransferResponse.MessageSize = intMessageSize;
return TransferResponse;
}
}
} // try
catch (Exception/*SocketException*/)
{
continue; // next try
}
finally
{
IncrementSequenceNumber();
}
}
}
Response responseTimeout = new Response();
responseTimeout.Error = "Timeout Error";
return responseTimeout;
}
private Response GetResponse(Request request)
{
request.header.ID = m_sequenceNumber;
request.header.RD = Options.Recursion;
var result = SendRequest(request);
return result;
}
public Response Query(string hostName, QType type, QClass @class)
{
if (String.IsNullOrWhiteSpace(hostName))
{
throw new ArgumentException("Invalid host name", "hostName");
}
var question = new Question(hostName, type, @class);
var response = FindResponse(question);
if (response != null)
{
return response;
}
var request = new Request();
request.AddQuestion(question);
response = GetResponse(request);
return response;
}
protected abstract Response SendRequest(Request request);
