private void Process(byte[] data, int length, IPEndPoint receiveAddress)
{
if (length < 16)
{
Console.WriteLine($"Rejecting short message from {receiveAddress}");
return;
}
if (data[0] != 68 || data[1] != 84 || data[2] != 84 || data[3] != 50)
{
Console.WriteLine($"Rejecting non TCPTunnel traffic from {receiveAddress}");
return;
}
int connectionID = BitConverter.ToInt32(data, 4);
short messageType = BitConverter.ToInt16(data, 8);
short messageLength = BitConverter.ToInt16(data, 10);
short messageSequence = BitConverter.ToInt16(data, 12);
short messageACK = BitConverter.ToInt16(data, 14);
if (BitConverter.IsLittleEndian)
{
connectionID = IPAddress.NetworkToHostOrder(connectionID);
messageType = IPAddress.NetworkToHostOrder(messageType);
messageLength = IPAddress.NetworkToHostOrder(messageLength);
messageSequence = IPAddress.NetworkToHostOrder(messageSequence);
messageACK = IPAddress.NetworkToHostOrder(messageACK);
}
if (messageLength != length - 16)
{
Console.WriteLine($"Rejecting bad payload TCPTunnel traffic from {receiveAddress}");
return;
}
//Payload is limited to 500 bytes
if (messageLength > 500)
{
Console.WriteLine($"Broken payload from {connectionID}");
return;
}
if (!connections.ContainsKey(connectionID))
{
//We're the server so we need to grab a new tcp connection for this client
if (ConnectLocalTCPConnection != null)
{
TcpClient newClient = ConnectLocalTCPConnection();
if (newClient == null)
{
//Server down?
Console.WriteLine($"Unable to connect to {settings.tcpPort}, is the server down?");
return;
}
Bucket newBucket = new Bucket(settings.connectionUpload, settings.connectionUpload, globalLimit);
Connection newConnection = new Connection(connectionID, settings, newClient, this, newBucket);
newConnection.sendEndpoint = receiveAddress;
connections[connectionID] = newConnection;
Console.WriteLine($"New connection {connectionID} from {receiveAddress} mapped to {newClient.Client.LocalEndPoint}");
}
else
{
//We can't do anything client side if we don't have an existing TCP connection, ignore the messages
Console.WriteLine($"Unknown UDP connection {connectionID} in client mode");
return;
}
}
Connection c = connections[connectionID];
ByteArray payload = null;
if (messageLength > 0)
{
payload = Recycler.Grab();
Array.Copy(data, 16, payload.data, 0, messageLength);
payload.length = messageLength;
}
c.HandleUDPData(messageType, messageLength, messageSequence, messageACK, payload, receiveAddress);
}
public Connection(int connectionID, TunnelSettings settings, TcpClient tcpClient, UDPServer udpServer, Bucket uploadBucket, Statistics statistics)
{
this.connectionID = connectionID;
this.tcpClient = tcpClient;
this.udpServer = udpServer;
this.uploadBucket = uploadBucket;
this.settings = settings;
this.statistics = statistics;
tcpSendTask = new Thread(new ThreadStart(SendLoop));
tcpSendTask.Name = "Connection.SendLoop." + connectionID;
tcpSendTask.Start();
tcpReceiveTask = new Thread(new ThreadStart(ReceiveLoop));
tcpReceiveTask.Name = "Connection.ReceiveLoop." + connectionID;
tcpReceiveTask.Start();
disconnectTime = DateTime.UtcNow.Ticks + (TimeSpan.TicksPerSecond * 5);
}
