void IncomingPacketHandler()
{
IncomingPacket incomingPacket = new IncomingPacket();
Packet packet = null;
UDPClient client = null;
while (IsRunning)
{
// Reset packet to null for the check below
packet = null;
if (packetInbox.Dequeue(100, ref incomingPacket))
{
packet = incomingPacket.Packet;
client = incomingPacket.Client;
if (packet != null)
{
#region ACK accounting
// Check the archives to see whether we already received this packet
lock (client.PacketArchive)
{
if (client.PacketArchive.Contains(packet.Header.Sequence))
{
if (packet.Header.Resent)
{
Logger.DebugLog("Received resent packet #" + packet.Header.Sequence);
}
else
{
Logger.Log(String.Format("Received a duplicate of packet #{0}, current type: {1}",
packet.Header.Sequence, packet.Type), Helpers.LogLevel.Warning);
}
// Avoid firing a callback twice for the same packet
continue;
}
else
{
// Keep the PacketArchive size within a certain capacity
while (client.PacketArchive.Count >= Settings.PACKET_ARCHIVE_SIZE)
{
client.PacketArchive.Dequeue(); client.PacketArchive.Dequeue();
client.PacketArchive.Dequeue(); client.PacketArchive.Dequeue();
}
client.PacketArchive.Enqueue(packet.Header.Sequence);
}
}
#endregion ACK accounting
#region ACK handling
// Handle appended ACKs
if (packet.Header.AppendedAcks)
{
lock (client.NeedAcks)
{
for (int i = 0; i < packet.Header.AckList.Length; i++)
{
client.NeedAcks.Remove(packet.Header.AckList[i]);
}
}
}
// Handle PacketAck packets
if (packet.Type == PacketType.PacketAck)
{
PacketAckPacket ackPacket = (PacketAckPacket)packet;
lock (client.NeedAcks)
{
for (int i = 0; i < ackPacket.Packets.Length; i++)
{
client.NeedAcks.Remove(ackPacket.Packets[i].ID);
}
}
}
#endregion ACK handling
packetEvents.BeginRaiseEvent(packet.Type, packet, client.Agent);
}
}
}
}
void SendPacket(UDPClient client, Packet packet, PacketCategory category, bool setSequence)
{
byte[] buffer;
int bytes;
// Set sequence implies that this is not a resent packet
if (setSequence)
{
// Reset to zero if we've hit the upper sequence number limit
Interlocked.CompareExchange(ref client.CurrentSequence, 0, 0xFFFFFF);
// Increment and fetch the current sequence number
uint sequence = (uint)Interlocked.Increment(ref client.CurrentSequence);
packet.Header.Sequence = sequence;
if (packet.Header.Reliable)
{
OutgoingPacket outgoing;
if (packet.Header.Resent && client.NeedAcks.TryGetValue(packet.Header.Sequence, out outgoing))
{
// This packet has already been sent out once, strip any appended ACKs
// off it and reinsert them into the outgoing ACK queue under the
// assumption that this packet will continually be rejected from the
// client or that the appended ACKs are possibly making the delivery fail
if (packet.Header.AckList.Length > 0)
{
Logger.DebugLog(String.Format("Purging ACKs from packet #{0} ({1}) which will be resent.",
packet.Header.Sequence, packet.GetType()));
lock (client.PendingAcks)
{
foreach (uint ack in packet.Header.AckList)
{
if (!client.PendingAcks.ContainsKey(ack))
{
client.PendingAcks[ack] = ack;
}
}
}
packet.Header.AppendedAcks = false;
packet.Header.AckList = new uint[0];
}
}
else
{
// Wrap this packet in a struct to track timeouts and resends
outgoing = new OutgoingPacket(packet);
// Add this packet to the list of ACK responses we are waiting on from this client
lock (client.NeedAcks)
client.NeedAcks[sequence] = outgoing;
// This packet is not a resend, check if the conditions are favorable
// to ACK appending
if (packet.Type != PacketType.PacketAck)
{
lock (client.PendingAcks)
{
int count = client.PendingAcks.Count;
if (count > 0 && count < 10)
{
// Append all of the queued up outgoing ACKs to this packet
packet.Header.AckList = new uint[count];
for (int i = 0; i < count; i++)
{
packet.Header.AckList[i] = client.PendingAcks.Values[i];
}
client.PendingAcks.Clear();
packet.Header.AppendedAcks = true;
}
}
}
}
// Update the sent time for this packet
outgoing.TickCount = Environment.TickCount;
}
else if (packet.Header.AckList.Length > 0)
{
// Sanity check for ACKS appended on an unreliable packet, this is bad form
Logger.Log("Sending appended ACKs on an unreliable packet", Helpers.LogLevel.Warning);
}
}
// Serialize the packet
buffer = packet.ToBytes();
bytes = buffer.Length;
//Stats.SentBytes += (ulong)bytes;
//++Stats.SentPackets;
UDPPacketBuffer buf = new UDPPacketBuffer(client.Address);
// Zerocode if needed
if (packet.Header.Zerocoded)
{
bytes = Helpers.ZeroEncode(buffer, bytes, buf.Data);
}
else
{
Buffer.BlockCopy(buffer, 0, buf.Data, 0, bytes);
}
buf.DataLength = bytes;
AsyncBeginSend(buf);
}
protected override void PacketReceived(UDPPacketBuffer buffer)
{
UDPClient client = null;
Packet packet = null;
int packetEnd = buffer.DataLength - 1;
IPEndPoint address = (IPEndPoint)buffer.RemoteEndPoint;
// Decoding
try
{
packet = Packet.BuildPacket(buffer.Data, ref packetEnd, buffer.ZeroData);
}
catch (MalformedDataException)
{
Logger.Log(String.Format("Malformed data, cannot parse packet:\n{0}",
Utils.BytesToHexString(buffer.Data, buffer.DataLength, null)), Helpers.LogLevel.Error);
}
// Fail-safe check
if (packet == null)
{
Logger.Log("Couldn't build a message from the incoming data", Helpers.LogLevel.Warning);
return;
}
//Stats.RecvBytes += (ulong)buffer.DataLength;
//++Stats.RecvPackets;
if (packet.Type == PacketType.UseCircuitCode)
{
UseCircuitCodePacket useCircuitCode = (UseCircuitCodePacket)packet;
Agent agent;
if (CompleteAgentConnection(useCircuitCode.CircuitCode.Code, out agent))
{
AddClient(agent, address);
if (clients.TryGetValue(agent.AgentID, out client))
{
Logger.Log("Activated UDP circuit " + useCircuitCode.CircuitCode.Code, Helpers.LogLevel.Info);
}
else
{
Logger.Log("Failed to locate newly created UDPClient", Helpers.LogLevel.Error);
return;
}
}
else
{
Logger.Log("Received a UseCircuitCode packet for an unrecognized circuit: " +
useCircuitCode.CircuitCode.Code.ToString(), Helpers.LogLevel.Warning);
return;
}
}
else
{
// Determine which agent this packet came from
if (!clients.TryGetValue(address, out client))
{
Logger.Log("Received UDP packet from an unrecognized source: " + address.ToString(),
Helpers.LogLevel.Warning);
return;
}
}
client.Agent.TickLastPacketReceived = Environment.TickCount;
// Reliable handling
if (packet.Header.Reliable)
{
// Queue up this sequence number for acknowledgement
QueueAck(client, (uint)packet.Header.Sequence);
//if (packet.Header.Resent) ++Stats.ReceivedResends;
}
// Inbox insertion
IncomingPacket incomingPacket;
incomingPacket.Client = client;
incomingPacket.Packet = packet;
// TODO: Prioritize the queue
packetInbox.Enqueue(incomingPacket);
}
public void AddClient(Agent agent, IPEndPoint endpoint)
{
UDPClient client = new UDPClient(this, agent, endpoint);
clients.Add(agent.AgentID, endpoint, client);
}
