public void CheckNAT(int port, string remotehost)
{
try
{
this.mRemoteHost = remotehost;
IPEndPoint localEP = new IPEndPoint(IPAddress.Any, port);
this.mClient = new UdpClient(localEP);
UDPState state = new UDPState {
Client = this.mClient,
Endpoint = localEP
};
this.mClient.BeginReceive(new AsyncCallback(this.AcceptCallback), state);
this.mClient.Send(this.mNatHeader, 4, remotehost, this._stunServerPort1);
}
catch (Exception)
{
}
}
public void AcceptCallback(IAsyncResult ar)
{
UdpClient client = ((UDPState) ar.AsyncState).Client;
IPEndPoint endpoint = ((UDPState) ar.AsyncState).Endpoint;
byte[] sourceArray = client.EndReceive(ar, ref endpoint);
if ((((sourceArray.Length == 10) && (sourceArray[0] == 8)) && ((sourceArray[1] == 0) && (sourceArray[2] == 0))) && (sourceArray[3] == 0))
{
if (this.epStun1 == null)
{
byte[] destinationArray = new byte[4];
Array.Copy(sourceArray, 4, destinationArray, 0, 4);
IPAddress address = new IPAddress(destinationArray);
int port = BitConverter.ToUInt16(sourceArray, 8);
this.epStun1 = new IPEndPoint(address, port);
UDPState state = new UDPState {
Client = this.mClient,
Endpoint = this.localEndPoint
};
this.mClient.BeginReceive(new AsyncCallback(this.AcceptCallback), state);
this.mClient.Send(this.mNatHeader, 4, this.mRemoteHost, this._stunServerPort2);
}
else
{
byte[] buffer3 = new byte[4];
Array.Copy(sourceArray, 4, buffer3, 0, 4);
IPAddress address2 = new IPAddress(buffer3);
int num2 = BitConverter.ToUInt16(sourceArray, 8);
IPEndPoint point2 = new IPEndPoint(address2, num2);
this.mClient.Close();
if (this.OnStunResults != null)
{
this.OnStunResults(this.epStun1, point2);
}
}
}
}