/// <summary>
/// Handle the bytes received from a socket.
/// </summary>
private static void HandlePayload(PhysicalSocket physical, byte[] payload, int length, IPEndPoint sender,
out RUDPPacketChannel channel,
out int packetId,
out int advertisedWindowSize,
out SACKSlot slot1,
out SACKSlot slot2,
out SACKSlot slot3,
out SACKSlot slot4,
out byte[] packetPayload)
{
int offset = 0;
//-- Protocol version
byte version = payload[offset];
offset++;
//-- Header information
byte sacksSlotCount = payload[offset];
offset++;
//-- Channel
byte channelByte = payload[offset];
offset++;
switch (channelByte)
{
case 0:
channel = RUDPPacketChannel.Undefined;
break;
case 10:
channel = RUDPPacketChannel.Ping;
break;
case 20:
channel = RUDPPacketChannel.PingRendezVous;
break;
case 30:
channel = RUDPPacketChannel.TearDown;
break;
case 40:
channel = RUDPPacketChannel.UserPacket;
break;
case 50:
channel = RUDPPacketChannel.ACK;
break;
case 70:
channel = RUDPPacketChannel.OutOfOrder;
break;
case 100:
channel = RUDPPacketChannel.KeepAlive;
break;
case 120:
channel = RUDPPacketChannel.MTUTuning;
break;
case 121:
channel = RUDPPacketChannel.MTUTuningACK;
break;
case 150:
channel = RUDPPacketChannel.Bandwidth01;
break;
case 151:
channel = RUDPPacketChannel.BandwidthResponse01;
break;
case 155:
channel = RUDPPacketChannel.Bandwidth02;
break;
case 156:
channel = RUDPPacketChannel.BandwidthResponse02;
break;
default:
throw new Exception("Unsupported channel type");
}
//-- Packet Id
packetId = BinaryHelper.ReadInt(payload, offset);
offset += 4;
//-- Control information : Advertised window
advertisedWindowSize = BinaryHelper.ReadInt(payload, offset);
offset += 4;
//-- Payload length
int payloadLength = BinaryHelper.ReadInt(payload, offset);
offset += 4;
//---- SACK Slots
slot1 = null;
slot2 = null;
slot3 = null;
slot4 = null;
int startPacketId;
int endPacketId;
if (sacksSlotCount > 0)
{
startPacketId = BinaryHelper.ReadInt(payload, offset);
offset += 4;
endPacketId = BinaryHelper.ReadInt(payload, offset);
offset += 4;
slot1 = new SACKSlot(startPacketId, endPacketId);
}
else offset += 8;
if (sacksSlotCount > 1)
{
startPacketId = BinaryHelper.ReadInt(payload, offset);
offset += 4;
endPacketId = BinaryHelper.ReadInt(payload, offset);
offset += 4;
slot2 = new SACKSlot(startPacketId, endPacketId);
}
else offset += 8;
if (sacksSlotCount > 2)
{
startPacketId = BinaryHelper.ReadInt(payload, offset);
offset += 4;
endPacketId = BinaryHelper.ReadInt(payload, offset);
offset += 4;
slot3 = new SACKSlot(startPacketId, endPacketId);
}
else offset += 8;
if (sacksSlotCount > 3)
{
startPacketId = BinaryHelper.ReadInt(payload, offset);
offset += 4;
endPacketId = BinaryHelper.ReadInt(payload, offset);
offset += 4;
slot4 = new SACKSlot(startPacketId, endPacketId);
}
else offset += 8;
//-- Payload
packetPayload = new byte[payloadLength];
if (payloadLength > 0)
Buffer.BlockCopy(payload, offset, packetPayload, 0, payloadLength);
}
static private void RegisterPhysicalSocket(PhysicalSocket physical)
{
EndPoint tempEndPoint = (EndPoint)physical._canReceiveFromEndPoint;
physical._socket.BeginReceiveFrom(physical._receiveBuffer, 0, physical._receiveBuffer.Length, SocketFlags.None, ref tempEndPoint, new AsyncCallback(OnEndReceive), physical);
}
private static bool SocketSendACK(RUDPSocket rudp,
PhysicalSocket physical,
IPEndPoint remoteEndPoint,
byte[] rudpPayload)
{
try
{
physical._socket.SendTo(rudpPayload, remoteEndPoint);
//physical._socket.BeginSendTo(rudpPayload, 0, rudpPayload.Length, SocketFlags.None, rudp._remoteEndPoint, null, null);
}
catch (SocketException exception)
{
if (rudp != null)
OnSocketUnhandledError(rudp, SocketErrorToRUDPSocketError(exception.SocketErrorCode), null);
return false;
}
if (rudp != null)
rudp._lastACKSendTS = HiResTimer.MicroSeconds;
return true;
}
/// <summary>
/// Static method to get/create a PhysicalSocket
/// </summary>
/// <param name="endPoint">The binded end point</param>
internal static PhysicalSocket GetInstance(IPEndPoint endPoint)
{
lock (_physicals)
{
PhysicalSocket physical;
bool isAnyEndPoint = endPoint.Equals(new IPEndPoint(IPAddress.Any, 0));
// Check if there is already an existing instance
if (!isAnyEndPoint)
{
if (_physicals.TryGetValue(endPoint, out physical))
return physical;
// In case no instance exists, create one
physical = new PhysicalSocket();
physical.Bind(endPoint);
RegisterPhysicalSocket(physical);
_physicals.Add(endPoint, physical);
}
else
{
physical = new PhysicalSocket();
while (true)
{
int port = new Random().Next(Int16.MaxValue);
IPAddress localAddress = LocalIPAddress(ProtocolType.IPv4);
endPoint = new IPEndPoint(localAddress, port);
// In case no instance exists, create one
try
{
physical.Bind(endPoint);
break;
}
catch { }
}
RegisterPhysicalSocket(physical);
_physicals.Add(endPoint, physical);
}
return physical;
}
}
/// <summary>
/// Release a PhysicalSocket instance and all its resources.
/// </summary>
/// <param name="physical">The socket to release</param>
internal static void ReleaseInstance(PhysicalSocket physical)
{
lock (_physicals)
{
physical.Dispose();
_physicals.Remove((IPEndPoint)physical._socket.LocalEndPoint);
}
}
/// <summary>
/// Called when we have an error on a socket.
/// </summary>
static internal void OnSocketUnhandledError(PhysicalSocket physical, IPEndPoint remoteEndPoint, SocketError error)
{
//---- Get the socket
RUDPSocket rudp;
physical._connectedRDUPsLock.EnterReadLock();
try
{
if (!physical._connectedRDUPs.TryGetValue(remoteEndPoint, out rudp))
return; // Released socket
}
finally
{
physical._connectedRDUPsLock.ExitReadLock();
}
//---- Handle the error
OnSocketUnhandledError(rudp, SocketErrorToRUDPSocketError(error), null);
}
private static RUDPSocket HandlePing(PhysicalSocket physical, IPEndPoint sender, int packetId, RUDPPacketChannel channel)
{
RUDPSocket rudp = null;
physical._connectedRDUPsLock.EnterReadLock();
physical._connectedRDUPs.TryGetValue(sender, out rudp);
physical._connectedRDUPsLock.ExitReadLock();
//---- Ping
if (channel == RUDPPacketChannel.Ping)
{
//-- This connection already exist, duplicated Ping
if (rudp != null)
{
// Resend the ACK
rudp._sackWindow.OnReceivePacket(packetId);
return null;
}
//-- No accepting socket
if (physical._acceptingRDUP == null)
{
// Maybe the socket is not yet ready for accepting, do nothing
return null;
}
//-- Accept
rudp = physical.OnEndAccept(sender, packetId);
//-- ACK connection
rudp._sackWindow.OnReceivePacket(packetId);
//return physical._acceptingRDUP;
return rudp;
}
//---- Ping , with Rendez vous
if (rudp != null && rudp._status == RUDPSocketStatus.Connecting && rudp._isRendezVousMode)
{
//---- End of connection
rudp._status = RUDPSocketStatus.Connected;
rudp.OnEndConnect(RUDPSocketError.Success);
//---- Accept the rendez vous connection
rudp._sackWindow.OnReceivePacket(packetId);
return rudp;
}
return null;
}
private static void HandlePacket(PhysicalSocket physical,
IPEndPoint sender,
RUDPPacketChannel channel,
int packetId,
int advertisedWindowSize,
SACKSlot slot1, SACKSlot slot2, SACKSlot slot3, SACKSlot slot4,
byte[] payload)
{
RUDPSocket rudp = null;
//---- PING
if (channel == RUDPPacketChannel.Ping || channel == RUDPPacketChannel.PingRendezVous)
{
rudp = HandlePing(physical, sender, packetId, channel);
// Do not handle this message
if (rudp == null)
return;
}
//---- Search the socket
if (rudp == null)
{
physical._connectedRDUPsLock.EnterReadLock();
physical._connectedRDUPs.TryGetValue(sender, out rudp);
physical._connectedRDUPsLock.ExitReadLock();
}
//---- Direct send of ACK, because socket can be shutdowned and removed
if (channel == RUDPPacketChannel.TearDown)
{
byte[] packetPayload = MakePacketPayload(rudp, -1, RUDPPacketChannel.ACK, new SACKSlot(packetId, packetId), null, null, null, null, 0, 0);
SocketSendACK(rudp, physical, sender, packetPayload);
PayloadManager.Deallocate(RUDPPacketChannel.ACK, packetPayload);
}
//---- Released socket
if (rudp == null)
return;
#if CONSOLE_TRACE
if (packetId > -1)
Trace("Handle packet (" + rudp.Handle + ")(" + channel + "):" + packetId);
#endif
//---- Advertised window
rudp._controlWindow.OnReceiveAdvertisedWindow(advertisedWindowSize);
//---- Handle ACKs
HandleACKs(rudp, slot1, slot2, slot3, slot4);
if (channel == RUDPPacketChannel.ACK)
return;
//---- Non reliable messages
if (packetId < 0)
{
//-- Bandwidth
if (channel == RUDPPacketChannel.Bandwidth01)
{
PushPacketToSend(rudp, false, RUDPPacketChannel.BandwidthResponse01, null, 0, 0);
return;
}
else if (channel == RUDPPacketChannel.Bandwidth02)
{
PushPacketToSend(rudp, false, RUDPPacketChannel.BandwidthResponse02, payload, 0, 8);
return;
}
else if (channel == RUDPPacketChannel.BandwidthResponse01)
{
rudp._bandwidthResponse01TS = HiResTimer.MicroSeconds;
}
else if (channel == RUDPPacketChannel.BandwidthResponse02)
{
//---- Calculate bandwidth
// Bdw (Bytes / milli-sec)
long now = HiResTimer.MicroSeconds;
double delay = (now - rudp._bandwidthResponse01TS) / 1000;
if (delay < 0.001)
delay = 0.001;
// Arrival Speed
double arrivalSpeed = (RUDPHeaderLength + UDPHeaderLength) / delay;
// RTT
double currentRtt = (now - BinaryHelper.ReadInt(payload, 0)) / 1000;
if (currentRtt < 0.001)
currentRtt = 0.001;
// BDP = Bandwidth(Byte / Ms) * RTT;
double bandwidth = (long)(arrivalSpeed * currentRtt);
rudp._bandwidth = (long)(rudp._bandwidth * 0.875f + bandwidth * 0.125f);
}
//-- MTU Tuning
else if (channel == RUDPPacketChannel.MTUTuning)
{
rudp._pmtuDiscovery.OnReceiveProbe(payload.Length);
return;
}
else if (channel == RUDPPacketChannel.MTUTuningACK)
{
rudp._pmtuDiscovery.OnReceiveProbeACK(payload);
return;
}
//if ((rudp._incomingNonReliablePackets.Count * rudp._mtu) >= rudp._receiveSize)
//return;
RUDPIngoingPacket nonReliablePacket = new RUDPIngoingPacket(rudp, packetId, payload, channel, HiResTimer.MicroSeconds);
rudp._incomingPackets.AddPacket(nonReliablePacket);
rudp.HandleNextUserPacket(false);
return;
}
//---- Do not process a duplicated packets
bool isDuplicatedPacket;
isDuplicatedPacket = (packetId <= rudp._incomingPackets.CurrentPacketId);
if (!isDuplicatedPacket)
isDuplicatedPacket = rudp._incomingPackets.ContainsPacket(packetId);
//---- Can I receive the packet now ?
bool canReceive = rudp._controlWindow.CanReceive(packetId, payload.Length);
//---- Send the ACK
if (channel != RUDPPacketChannel.Ping && channel != RUDPPacketChannel.PingRendezVous)
if (canReceive || // Can receive, then we send ACK
(!canReceive && isDuplicatedPacket)) // Is duplicated, then already in the list -> send another ACK
rudp._sackWindow.OnReceivePacket(packetId);
//---- Check if we can handle this message
if (!canReceive || isDuplicatedPacket)
return;
//---- If we are not connected, we cannot hanlde messages ! We need a connection before.
if (rudp._status != RUDPSocketStatus.Connected && channel == RUDPPacketChannel.UserPacket)
return;
//---- Check for Out of order packets
if (rudp._incomingPackets.Count > 0)
{
int greaterPacketId = rudp._incomingPackets.LastPacketId;
if (packetId != greaterPacketId + 1)
{
byte[] oooPayload = new byte[8];
// start packet
BinaryHelper.WriteInt(greaterPacketId + 1, oooPayload, 0);
// end packet
BinaryHelper.WriteInt(packetId - 1, oooPayload, 4);
PushPacketToSend(rudp, false, RUDPPacketChannel.OutOfOrder, oooPayload, 0, 8);
}
}
//---- Receive Out of order notification
if (channel == RUDPPacketChannel.OutOfOrder)
{
rudp._controlWindow.OnOutOfOrder(BinaryHelper.ReadInt(payload, 0), BinaryHelper.ReadInt(payload, 4));
}
//---- TEAR DOWN
if (channel == RUDPPacketChannel.TearDown)
{
// Initiate the close process
if (rudp._status == RUDPSocketStatus.Connected)
{
// Notify control window
rudp._controlWindow.OnReceive(null);
// Start shutdown
AsyncShutdown(rudp);
}
return;
}
//---- Add the packet to incoming list
RUDPIngoingPacket packet = new RUDPIngoingPacket(rudp, packetId, payload, channel, HiResTimer.MicroSeconds);
// Notify control window
rudp._controlWindow.OnReceive(packet);
rudp._incomingPackets.AddPacket(packet);
//------ Handle the ordered ingoing packets
rudp.HandleNextUserPacket(false);
}
public void Bind(IPEndPoint endPoint)
{
// Get the associated physical socket
_physical = RUDPStack.GetInstance(endPoint);
}
public void Bind(IPEndPoint endPoint)
{
// Get the associated physical socket
_physical = RUDPStack.GetInstance(endPoint);
}
