private unsafe void ReceiveDatagram(IAsyncResult ar)
{
IPEndPoint fromAddr = new IPEndPoint(IPAddress.Any, 0);
byte[] data = connection.EndReceive(ar, ref fromAddr);
if (!shuttingDown) connection.BeginReceive(ReceiveDatagram, null);
#region "ENet Structure Handling"
var handle = GCHandle.Alloc(data, GCHandleType.Pinned);
IntPtr dataStart = handle.AddrOfPinnedObject();
ENetProtocolHeader header = (ENetProtocolHeader)Marshal.PtrToStructure(dataStart, typeof(ENetProtocolHeader));
Util.ToHostOrder(ref header.PeerID);
ushort flag = (ushort)(header.PeerID & PROTOCOL_HEADER_FLAG_MASK);
header.PeerID &= unchecked((ushort)~(uint)PROTOCOL_HEADER_FLAG_MASK);
ENetPeer? peer = null;
if (header.PeerID != PROTOCOL_MAXIMUM_PEER_ID) //peer remains null if the first command is expected to be a connect
{
try
{
peer = Peers[header.PeerID];
if (peer.Value.State == ENetPeerState.Disconnected ||
peer.Value.State == ENetPeerState.Zombie ||
//Don't include ENET_HOST_BROADCAST, it's meant for clients broadcasting the connect packet and communicating with any server that responds
!peer.Value.Address.Equals(fromAddr) /* && peer.Value.Address != ENET_HOST_BROADCAST */)
{
goto finalPacket; //The peer is disconnected, dead or the packets origin doesn't match the peer - Ignore them
}
}
catch (System.Collections.Generic.KeyNotFoundException)
{
goto finalPacket; //The client doesn't exist and this doesn't follow connection protocol - Ignore them
}
}
int currentDataOffset = ((flag & PROTOCOL_HEADER_FLAG_SENT_TIME) != 0) ? sizeof(ENetProtocolHeader) : sizeof(ENetProtocolHeader) - 2; //sentTime is 2 bytes
while (currentDataOffset < data.Length)
{
ENetProtocol packet = (ENetProtocol)Marshal.PtrToStructure(dataStart + currentDataOffset, typeof(ENetProtocol));
Util.ToHostOrder(ref packet.Header.ReliableSequenceNumber);
if (packet.Header.ChannelID >= ChannelLayout.ChannelCount()) continue;
ENetCommand command = (ENetCommand)(packet.Header.Command & (byte)ENetCommand.COMMAND_MASK);
if(command >= ENetCommand.COUNT) continue;
if (peer == null && command != ENetCommand.CONNECT) return; //Peer was following connection protocol but didn't send the connect first
currentDataOffset += command.Size();
if (currentDataOffset > data.Length) return; //The ENetCommand is larger than the remaining data
switch (command)
{
case ENetCommand.ACKNOWLEDGE:
Util.ToHostOrder(ref packet.Acknowledge.ReceivedReliableSequenceNumber);
Util.ToHostOrder(ref packet.Acknowledge.ReceivedSentTime);
//TODO: Handle Acknowledge
break;
case ENetCommand.BANDWIDTH_LIMIT:
Util.ToHostOrder(ref packet.BandwidthLimit.IncomingBandwidth);
Util.ToHostOrder(ref packet.BandwidthLimit.OutgoingBandwidth);
//TODO: Handle Bandwidth Limit
break;
case ENetCommand.CONNECT:
Console.WriteLine("A connected peer sent a connect packet. WTF are they doing?");
Util.ToHostOrder(ref packet.Connect.MTU);
Util.ToHostOrder(ref packet.Connect.WindowSize);
Util.ToHostOrder(ref packet.Connect.ChannelCount);
Util.ToHostOrder(ref packet.Connect.IncomingBandwidth);
Util.ToHostOrder(ref packet.Connect.OutgoingBandwidth);
Util.ToHostOrder(ref packet.Connect.PacketThrottleInterval);
Util.ToHostOrder(ref packet.Connect.PacketThrottleAcceleration);
Util.ToHostOrder(ref packet.Connect.PacketThrottleDeceleration);
Util.ToHostOrder(ref packet.Connect.SessionID);
peer = HandleConnect(fromAddr, packet.Connect);
break;
case ENetCommand.DISCONNECT:
Util.ToHostOrder(ref packet.Disconnect.Data);
//TODO: Handle Disconnect
break;
case ENetCommand.PING:
//Ping has no handling in the real ENet
break;
case ENetCommand.SEND_FRAGMENT:
Util.ToHostOrder(ref packet.SendFragment.DataLength); //We have to assume the fragment is the right type for the channel until I figure out how it indicates it
Util.ToHostOrder(ref packet.SendFragment.StartSequenceNumber);
Util.ToHostOrder(ref packet.SendFragment.FragmentCount);
Util.ToHostOrder(ref packet.SendFragment.FragmentNumber);
Util.ToHostOrder(ref packet.SendFragment.TotalLength);
Util.ToHostOrder(ref packet.SendFragment.FragmentOffset);
byte[] fragmentData = new byte[packet.SendFragment.DataLength];
Marshal.Copy(dataStart + currentDataOffset, fragmentData, 0, packet.SendFragment.DataLength);
currentDataOffset += packet.SendFragment.DataLength;
HandleReliable(peer.Value, packet, true, fragmentData);
break;
case ENetCommand.SEND_RELIABLE:
Util.ToHostOrder(ref packet.SendReliable.DataLength);
if ((ChannelLayout[packet.Header.ChannelID] & ENetSendType.RELIABLE) == 0) //Each of the data handlers uses this to quickly discard any data not matching the channels send type
{
currentDataOffset += packet.SendReliable.DataLength;
break;
}
byte[] reliableData = new byte[packet.SendReliable.DataLength];
Marshal.Copy(dataStart + currentDataOffset, reliableData, 0, packet.SendReliable.DataLength);
currentDataOffset += packet.SendReliable.DataLength;
HandleReliable(peer.Value, packet, false, reliableData);
break;
case ENetCommand.SEND_UNRELIABLE:
Util.ToHostOrder(ref packet.SendUnreliable.DataLength);
if ((ChannelLayout[packet.Header.ChannelID] & ENetSendType.UNRELIABLE) == 0)
{
currentDataOffset += packet.SendUnreliable.DataLength;
break;
}
Util.ToHostOrder(ref packet.SendUnreliable.UnreliableSequenceNumber);
byte[] unreliableData = new byte[packet.SendUnreliable.DataLength];
Marshal.Copy(dataStart + currentDataOffset, unreliableData, 0, packet.SendUnreliable.DataLength);
currentDataOffset += packet.SendUnreliable.DataLength;
HandleUnreliable(peer.Value, packet.SendUnreliable, unreliableData);
break;
case ENetCommand.SEND_UNSEQUENCED:
Util.ToHostOrder(ref packet.SendUnsequenced.DataLength);
if ((ChannelLayout[packet.Header.ChannelID] & ENetSendType.UNSEQUENCED) == 0)
{
currentDataOffset += packet.SendUnsequenced.DataLength;
break;
}
Util.ToHostOrder(ref packet.SendUnsequenced.UnsequencedGroup);
byte[] unsequencedData = new byte[packet.SendUnsequenced.DataLength];
Marshal.Copy(dataStart + currentDataOffset, unsequencedData, 0, packet.SendUnsequenced.DataLength);
currentDataOffset += packet.SendUnsequenced.DataLength;
HandleUnsequenced(peer.Value, packet.SendUnsequenced, unsequencedData);
break;
case ENetCommand.THROTTLE_CONFIGURE:
Util.ToHostOrder(ref packet.ThrottleConfigure.PacketThrottleInterval);
Util.ToHostOrder(ref packet.ThrottleConfigure.PacketThrottleAcceleration);
Util.ToHostOrder(ref packet.ThrottleConfigure.PacketThrottleDeceleration);
//TODO: Handle Throttle Configure
break;
case ENetCommand.VERIFY_CONNECT:
Util.ToHostOrder(ref packet.VerifyConnect.MTU);
Util.ToHostOrder(ref packet.VerifyConnect.WindowSize);
Util.ToHostOrder(ref packet.VerifyConnect.ChannelCount);
Util.ToHostOrder(ref packet.VerifyConnect.IncomingBandwidth);
Util.ToHostOrder(ref packet.VerifyConnect.OutgoingBandwidth);
Util.ToHostOrder(ref packet.VerifyConnect.PacketThrottleInterval);
Util.ToHostOrder(ref packet.VerifyConnect.PacketThrottleAcceleration);
Util.ToHostOrder(ref packet.VerifyConnect.PacketThrottleDeceleration);
//TODO: Handle Verify Connect
break;
default:
goto finalPacket;
}
}
finalPacket:
handle.Free();
#endregion
if (shuttingDown) shutdownComplete.Set();
}
