private ByteArray GetUDPMessageData(short type, short sequence, ByteArray payload)
{
ByteArray byteArray = Recycler.Grab();
byteArray.length = 16;
//Write magic header, DTT2
byteArray.data[0] = 68;
byteArray.data[1] = 84;
byteArray.data[2] = 84;
byteArray.data[3] = 50;
WriteInt32(connectionID, byteArray.data, 4);
WriteInt16(type, byteArray.data, 8);
if (payload == null)
{
WriteInt16(0, byteArray.data, 10);
}
else
{
byteArray.length += payload.length;
WriteInt16(payload.length, byteArray.data, 10);
Array.Copy(payload.data, 0, byteArray.data, 16, payload.length);
Recycler.Release(payload);
}
WriteInt16(sequence, byteArray.data, 12);
WriteInt16(receiveSequence, byteArray.data, 14);
return(byteArray);
}
public ByteArray GetRate()
{
ByteArray sendData = Recycler.Grab();
sendData.length = 4;
WriteInt32(settings.connectionDownload, sendData.data, 0);
return(GetUDPMessageData(10, 0, sendData));
}
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($"Unable to connect to {settings.tcpPort}, is the server down?");
return;
}
Bucket newBucket = new Bucket(settings.connectionUpload, settings.connectionUpload, null);
Connection newConnection = new Connection(connectionID, settings, newClient, this, newBucket, statistics);
newConnection.sendEndpoint = receiveAddress;
connections.TryAdd(connectionID, newConnection);
Console.WriteLine($"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 bool GetUDPMessage(out ByteArray sendMessage)
{
sendMessage = null;
//Not enough data to send a packet
if (!uploadBucket.TestBytes(500))
{
return(false);
}
long currentTime = DateTime.UtcNow.Ticks;
//Let the other side know they can stop sending the rate setup message
if (sendRateAcknowledge)
{
sendRateAcknowledge = false;
sendMessage = GetRateAcknowledge();
return(true);
}
//Connection setup, prevents the other side from sending too fast
if (!receivedRateMessage && currentTime > nextRateMessageTime)
{
nextRateMessageTime = currentTime + TimeSpan.TicksPerSecond;
sendMessage = GetRate();
return(true);
}
//If we have more than 1 second of data to send, or our bucket is low, let's skip the double send
double uploadMaxed = uploadBucket.bucketBytes / (double)uploadBucket.bucketMax;
bool efficencyMode = queuedBytes > uploadBucket.bucketMax || uploadMaxed < 0.5d;
//Retransmit half as often
long efficencyOffset = 0;
if (efficencyMode)
{
efficencyOffset = TimeSpan.TicksPerMillisecond * settings.retransmit;
}
OutgoingMessage om;
//Send retransmits
if (sendMessage == null && udpRetransmitSendQueue.TryPeek(out om))
{
if (currentTime > om.sendTime + efficencyOffset)
{
bool skipping = true;
while (skipping)
{
if (udpRetransmitSendQueue.TryDequeue(out om))
{
//Don't send messages they have acknowledged
if (AckGreaterThan(om.sequence, sendAck))
{
//Send back to the retransmit queue
om.sendTime = currentTime + (settings.retransmit * TimeSpan.TicksPerMillisecond);
udpRetransmitSendQueue.Enqueue(om);
//Send
sendMessage = om.data;
break;
}
else
{
Recycler.Release(om.data);
}
}
else
{
skipping = false;
}
}
}
}
//Send double sends
if (sendMessage == null)
{
bool skipping = true;
while (skipping)
{
if (udpDoubleSendQueue.TryPeek(out om))
{
//This isn't ready to transmit yet.
if (om.sendTime > currentTime + efficencyOffset)
{
break;
}
}
if (udpDoubleSendQueue.TryDequeue(out om))
{
if (AckGreaterThan(om.sequence, sendAck))
{
//Send to the retransmit queue
om.sendTime = currentTime + (settings.retransmit * TimeSpan.TicksPerMillisecond);
udpRetransmitSendQueue.Enqueue(om);
//Send
sendMessage = om.data;
break;
}
else
{
//Already ACK'd, skip it
Recycler.Release(om.data);
}
}
else
{
skipping = false;
}
}
}
//Take new waiting data and build a message if we have less than 10000 queue'd packets
int ackDiff = sendSequence - sendAck;
if (ackDiff < 0)
{
ackDiff = ackDiff + ushort.MaxValue;
}
if (sendMessage == null && ackDiff < 10000 && udpSendQueue.Count > 0)
{
ByteArray payload = Recycler.Grab();
ByteArray addMessage;
//Grab upto 500 bytes
while (udpSendQueue.TryPeek(out addMessage))
{
if (payload.length + addMessage.length > 500)
{
break;
}
else
{
udpSendQueue.TryDequeue(out addMessage);
Interlocked.Add(ref queuedBytes, -addMessage.length);
Array.Copy(addMessage.data, 0, payload.data, payload.length, addMessage.length);
payload.length += addMessage.length;
Recycler.Release(addMessage);
}
}
om = new OutgoingMessage();
om.sequence = sendSequence++;
om.data = GetUDPMessageData(1, om.sequence, payload);
//Send it to the correct retransmit queue
if (!efficencyMode && settings.initialRetransmit > 0)
{
om.sendTime = currentTime + (settings.initialRetransmit * TimeSpan.TicksPerMillisecond);
udpDoubleSendQueue.Enqueue(om);
}
else
{
om.sendTime = currentTime + (settings.retransmit * TimeSpan.TicksPerMillisecond);
udpRetransmitSendQueue.Enqueue(om);
}
//Send
sendMessage = om.data;
statistics.sentUniquePackets++;
statistics.sentUniqueBytes += payload.length;
}
//Send heartbeats
if (sendMessage == null && currentTime > sendTime)
{
sendMessage = GetHeartbeat();
}
//Send
if (sendMessage != null)
{
sendTime = currentTime + (TimeSpan.TicksPerMillisecond * 100);
//Update ACK
WriteInt16(receiveSequence - 1, sendMessage.data, 14);
while (!uploadBucket.RequestBytes(sendMessage.length))
{
Thread.Sleep(1);
}
return(true);
}
return(false);
}
public bool GetUDPMessage(out ByteArray sendMessage)
{
sendMessage = null;
//Not enough data to send a packet
if (!uploadBucket.TestBytes(500))
{
return(false);
}
long currentTime = DateTime.UtcNow.Ticks;
//Send retransmits
OutgoingMessage om;
if (udpDoubleSendQueue.TryPeek(out om))
{
if (currentTime > om.sendTime)
{
if (udpDoubleSendQueue.TryDequeue(out om))
{
//Send to the retransmit queue
om.sendTime = currentTime + (settings.retransmit * TimeSpan.TicksPerMillisecond);
udpRetransmitSendQueue.Enqueue(om);
//Send
sendMessage = om.data;
}
}
}
if (sendMessage == null && udpRetransmitSendQueue.TryPeek(out om))
{
if (currentTime > om.sendTime)
{
bool skipping = true;
while (skipping)
{
if (udpRetransmitSendQueue.TryDequeue(out om))
{
//Don't send messages they have acknowledged
if (AckGreaterThan(om.sequence, sendAck))
{
//Send back to the retransmit queue
om.sendTime = currentTime + (settings.retransmit * TimeSpan.TicksPerMillisecond);
udpRetransmitSendQueue.Enqueue(om);
//Send
sendMessage = om.data;
break;
}
else
{
Recycler.Release(om.data);
}
}
else
{
skipping = false;
}
}
}
}
//Take new waiting data and build a message if we have less than 1000 queue'd packets
int ackDiff = sendSequence - sendAck;
if (ackDiff < 0)
{
ackDiff = ackDiff + ushort.MaxValue;
}
if (sendMessage == null && ackDiff < 1000 && udpSendQueue.Count > 0)
{
ByteArray payload = Recycler.Grab();
ByteArray addMessage;
//Grab upto 500 bytes
while (udpSendQueue.TryPeek(out addMessage))
{
if (payload.length + addMessage.length > 500)
{
break;
}
else
{
udpSendQueue.TryDequeue(out addMessage);
Array.Copy(addMessage.data, 0, payload.data, payload.length, addMessage.length);
payload.length += addMessage.length;
Recycler.Release(addMessage);
}
}
om = new OutgoingMessage();
om.sequence = sendSequence++;
om.data = GetUDPMessageData(1, om.sequence, payload);
//Send it to the correct retransmit queue
if (settings.initialRetransmit > 0)
{
om.sendTime = currentTime + (settings.initialRetransmit * TimeSpan.TicksPerMillisecond);
udpDoubleSendQueue.Enqueue(om);
}
else
{
om.sendTime = currentTime + (settings.retransmit * TimeSpan.TicksPerMillisecond);
udpRetransmitSendQueue.Enqueue(om);
}
//Send
sendMessage = om.data;
}
//Send heartbeats
if (sendMessage == null && currentTime > sendTime)
{
sendMessage = GetHeartbeat();
}
if (sendMessage != null)
{
sendTime = currentTime + (TimeSpan.TicksPerMillisecond * 100);
//Update ACK
WriteInt16(receiveSequence - 1, sendMessage.data, 14);
while (!uploadBucket.RequestBytes(sendMessage.length))
{
Thread.Sleep(1);
}
return(true);
}
return(false);
}