private static STUN_Message DoTransaction(STUN_Message request, Socket socket, IPEndPoint remoteEndPoint)
{
byte[] buffer = request.ToByteData();
DateTime now = DateTime.Now;
while (now.AddSeconds(2.0) > DateTime.Now)
{
try
{
socket.SendTo(buffer, remoteEndPoint);
// MessageBox.Show(string.Concat(new object[] { "My local IpAddress is :", IPAddress.Parse(((IPEndPoint)socket.LocalEndPoint).Address.ToString()), " I am connected on port number ", ((IPEndPoint)socket.LocalEndPoint).Port.ToString() }));
if (socket.Poll(100, SelectMode.SelectRead))
{
byte[] buffer2 = new byte[0x200];
socket.Receive(buffer2);
STUN_Message message = new STUN_Message();
message.Parse(buffer2);
if (request.TransactionID.Equals(message.TransactionID))
{
return(message);
}
}
}
catch (Exception)
{
}
}
return(null);
}
public static STUN_Result Query(string host, int port, Socket socket)
{
if (host == null)
{
throw new ArgumentNullException("host");
}
if (socket == null)
{
throw new ArgumentNullException("socket");
}
if (port < 1)
{
throw new ArgumentException("Port value must be >= 1 !");
}
if (socket.ProtocolType != ProtocolType.Udp)
{
throw new ArgumentException("Socket must be UDP socket !");
}
IPEndPoint remoteEndPoint = null;
try
{
remoteEndPoint = new IPEndPoint(Dns.GetHostAddresses(host)[0], port);
}
catch (Exception)
{
try
{
if (connectNet())
{
return(new STUN_Result(STUN_NetType.HttpPort80, null));
}
return(new STUN_Result(STUN_NetType.NoInternetSupport, null));
}
catch (Exception)
{
return(new STUN_Result(STUN_NetType.NoInternetSupport, null));
}
}
socket.ReceiveTimeout = 0xbb8;
socket.SendTimeout = 0xbb8;
STUN_Message request = new STUN_Message();
request.Type = STUN_MessageType.BindingRequest;
STUN_Message message2 = DoTransaction(request, socket, remoteEndPoint);
if (message2 == null)
{
return(new STUN_Result(STUN_NetType.UdpBlocked, null));
}
STUN_Message message3 = new STUN_Message();
message3.Type = STUN_MessageType.BindingRequest;
message3.ChangeRequest = new STUN_t_ChangeRequest(true, true);
if (socket.LocalEndPoint.Equals(message2.MappedAddress))
{
if (DoTransaction(message3, socket, remoteEndPoint) != null)
{
return(new STUN_Result(STUN_NetType.OpenInternet, message2.MappedAddress));
}
return(new STUN_Result(STUN_NetType.SymmetricUdpFirewall, message2.MappedAddress));
}
if (DoTransaction(message3, socket, remoteEndPoint) != null)
{
return(new STUN_Result(STUN_NetType.FullCone, message2.MappedAddress));
}
STUN_Message message5 = new STUN_Message();
message5.Type = STUN_MessageType.BindingRequest;
STUN_Message message6 = DoTransaction(message5, socket, message2.ChangedAddress);
if (message6 == null)
{
return(new STUN_Result(STUN_NetType.RestrictedCone, message2.MappedAddress));
//throw new Exception("STUN Test I(II) dind't get resonse !");
}
if (!message6.MappedAddress.Equals(message2.MappedAddress))
{
return(new STUN_Result(STUN_NetType.Symmetric, message2.MappedAddress));
}
STUN_Message message7 = new STUN_Message();
message7.Type = STUN_MessageType.BindingRequest;
message7.ChangeRequest = new STUN_t_ChangeRequest(false, true);
if (DoTransaction(message7, socket, message2.ChangedAddress) != null)
{
return(new STUN_Result(STUN_NetType.RestrictedCone, message2.MappedAddress));
}
return(new STUN_Result(STUN_NetType.PortRestrictedCone, message2.MappedAddress));
}