public void Stop()
{
//_stopTokenSource?.Cancel();
if (_stopTokenSource != null)
{
_stopTokenSource.Cancel();
}
if (_UdpListener != null)
{
_UdpListener.Close();
}
if (_UdpForwarder != null)
{
_UdpForwarder.Close();
}
//_udpListener?.Close();
//_udpForwarder?.Close();
/*try
* {
* _listeningTask?.Wait();
* _forwardingTask?.Wait();*/
if (_ListeningTask != null)
{
_ListeningTask.Abort();
}
if (_ForwardingTask != null)
{
_ForwardingTask.Abort();
}
/* }
* catch (AggregateException)
* {
* }*/
_stopTokenSource = null;
_UdpListener = null;
_UdpForwarder = null;
_ListeningTask = null;
_ForwardingTask = null;
_transactionClients = null;
_transactionTimeoutCancellationTokenSources = null;
OnStopped();
}
public bool Start()
{
_IPEndPoint = Utils.CreateIpEndPoint(_listenOn, 53);
_stopTokenSource = new MrTe.Threading.Tasks.CancellationTokenSource();
_transactionClients = new System.Collections.Generic.Dictionary <ushort, IPEndPoint>();
_transactionTimeoutCancellationTokenSources = new System.Collections.Generic.Dictionary <ushort, MrTe.Threading.Tasks.CancellationTokenSource>();
try
{
_UdpListener = new UdpClient(_IPEndPoint);
_UdpForwarder = new UdpClient(0);
}
catch (SocketException e)
{
Logger.Error("[Listener] Failed to start DNSAgent:\n{0}", e);
Stop();
return(false);
}
/*_listeningTask = Task.Run(async () =>
* {
*
* }, _stopTokenSource.Token);
*/
_ListeningTask = new Thread(new ThreadStart(ListeningTask_Run));
_ListeningTask.Start();
/*
* _forwardingTask = Task.Run(async () =>
* {
*
* }, _stopTokenSource.Token);
*
*/
_ForwardingTask = new Thread(new ThreadStart(ForwardingTask_Run));
_ForwardingTask.Start();
Logger.Info("Listening on {0}...", _IPEndPoint);
OnStarted();
return(true);
}
private bool ForwardMessage(DnsMessage message, IPEndPoint revicepoint, byte[] buf,
IPEndPoint targetNameServer, int queryTimeout,
bool useCompressionMutation)
{
DnsQuestion question = null;
if (message.Questions.Count > 0)
{
question = message.Questions[0];
}
byte[] responseBuffer = null;
try
{
if ((Equals(targetNameServer.Address, IPAddress.Loopback) ||
Equals(targetNameServer.Address, IPAddress.IPv6Loopback)) &&
targetNameServer.Port == ((IPEndPoint)_UdpListener.Client.LocalEndPoint).Port)
{
throw new InfiniteForwardingException(question);
}
byte[] sendBuffer;
if (useCompressionMutation)
{
message.Encode(false, out sendBuffer, true);
}
else
{
sendBuffer = buf;
}
_transactionClients[message.TransactionID] = revicepoint;
// Send to Forwarder
/*await _udpForwarder.SendAsync(sendBuffer, sendBuffer.Length, targetNameServer);*/
_UdpForwarder.Send(sendBuffer, sendBuffer.Length, targetNameServer);
if (_transactionTimeoutCancellationTokenSources.ContainsKey(message.TransactionID))
{
_transactionTimeoutCancellationTokenSources[message.TransactionID].Cancel();
}
MrTe.Threading.Tasks.CancellationTokenSource cancellationTokenSource = new MrTe.Threading.Tasks.CancellationTokenSource();
_transactionTimeoutCancellationTokenSources[message.TransactionID] = cancellationTokenSource;
return(true);
// Timeout task to cancel the request
/*try
* {*/
/*await Task.Delay(queryTimeout, cancellationTokenSource.Token);*/
Task.Delay(queryTimeout, cancellationTokenSource.Token);
if (!_transactionClients.ContainsKey(message.TransactionID))
{
return(false);
}
IPEndPoint ignoreEndPoint;
MrTe.Threading.Tasks.CancellationTokenSource ignoreTokenSource;
/*
* _transactionClients.TryRemove(message.TransactionID, out ignoreEndPoint);
* _transactionTimeoutCancellationTokenSources.TryRemove(message.TransactionID,
* out ignoreTokenSource);
*/
ignoreEndPoint = _transactionClients[message.TransactionID];
ignoreTokenSource = _transactionTimeoutCancellationTokenSources[message.TransactionID];
string warningText = message.Questions.Count > 0
? message.Questions[0].Name + " (Type " + message.Questions[0].RecordType + ")"
: "Transaction #" + message.TransactionID + "";
Logger.Warning("Query timeout for: {0}", warningText);
_transactionClients.Remove(message.TransactionID);
_transactionTimeoutCancellationTokenSources.Remove(message.TransactionID);
/*
* }
* catch (TaskCanceledException)
* {
* }
*/
}
catch (InfiniteForwardingException e)
{
Logger.Warning("[Forwarder.Send] Infinite forwarding detected for: {0} (Type {1})", e.Question.Name,
e.Question.RecordType);
Utils.ReturnDnsMessageServerFailure(message, out responseBuffer);
}
catch (SocketException e)
{
if (e.SocketErrorCode == SocketError.ConnectionReset) // Target name server port unreachable
{
Logger.Warning("[Forwarder.Send] Name server port unreachable: {0}", targetNameServer);
}
else
{
Logger.Error("[Forwarder.Send] Unhandled socket error: {0}", e.Message);
}
Utils.ReturnDnsMessageServerFailure(message, out responseBuffer);
}
catch (Exception e)
{
Logger.Error("[Forwarder] Unexpected exception:\n{0}", e);
Utils.ReturnDnsMessageServerFailure(message, out responseBuffer);
}
// If we got some errors
if (responseBuffer != null)
{
/*await _udpListener.SendAsync(responseBuffer, responseBuffer.Length, originalUdpMessage.RemoteEndPoint);*/
_UdpListener.Send(responseBuffer, responseBuffer.Length, revicepoint);
}
return(true);
}
