bool SendRawPacketInternal(RawPacket packet, byte[] buffer, Socket socket,
GameEncryptionSession encryption, bool server)
{
if (packet == null)
{
throw new ArgumentNullException(nameof(packet));
}
if (packet.Payload.Length > PacketHeader.MaxPayloadSize)
{
throw new ArgumentException("Packet is too big.", nameof(packet));
}
var header = new PacketHeader((ushort)packet.Payload.Length,
Proxy.Processor.Serializer.GameMessages.NameToCode[packet.Name]);
lock (socket)
{
PacketProcessor.WriteHeader(header, buffer);
Buffer.BlockCopy(packet.Payload, 0, buffer, PacketHeader.HeaderSize, header.Length);
try
{
return(SendInternal(buffer, header.FullLength, false, socket, encryption, server));
}
catch (SocketDisconnectedException)
{
// Normal disconnection.
return(false);
}
}
}
bool SendPacketInternal(Direction direction, SerializablePacket packet, Memory <byte> buffer,
GameBinaryWriter writer, Socket socket, GameEncryptionSession encryption, bool server,
bool direct)
{
if (packet == null)
{
throw new ArgumentNullException(nameof(packet));
}
var payload = Proxy.Serializer.Serialize(packet).AsMemory();
if (payload.Length > PacketHeader.MaxPayloadSize)
{
throw new ArgumentException("Packet is too large.", nameof(packet));
}
var code = Proxy.Serializer.GameMessages.NameToCode[packet.Name];
var original = payload;
var send = Proxy.InvokeSent(this, direction, code, ref payload, direct);
if (!send)
{
return(false);
}
// A handler might have created a packet that's too large.
if (payload.Length > PacketHeader.MaxPayloadSize)
{
_log.Error(
"{0}: Forged packet {1} is too large ({2} bytes) to be sent correctly after running handlers; sending original",
direction.ToDirectionString(), packet.Name, payload.Length);
payload = original;
}
lock (socket)
{
var header = new PacketHeader((ushort)payload.Length, code);
WriteHeader(writer, header);
payload.CopyTo(buffer.Slice(PacketHeader.HeaderSize, header.Length));
try
{
return(SendInternal(buffer.Slice(0, header.FullLength), false, socket, encryption, server));
}
catch (SocketDisconnectedException)
{
// Normal disconnection.
return(false);
}
}
}
void ReceiveInternal(Memory <byte> data, Socket socket, GameEncryptionSession encryption,
bool server)
{
RunGuarded(true, server, () =>
{
socket.ReceiveFull(data.GetArray());
lock (_encryptionLock)
if (encryption != null)
{
encryption.Decrypt(data);
}
});
}
void ReceiveInternal(byte[] data, int length, Socket socket, GameEncryptionSession encryption,
bool server)
{
RunGuarded(true, server, () =>
{
socket.ReceiveFull(data, 0, length);
if (encryption != null)
{
lock (encryption)
encryption.Decrypt(data, 0, length);
}
});
}
bool SendInternal(Memory <byte> data, bool rethrow, Socket socket,
GameEncryptionSession encryption, bool server)
{
return(RunGuarded(rethrow, server, () =>
{
lock (_encryptionLock)
if (encryption != null)
{
encryption.Encrypt(data);
}
lock (socket)
socket.SendFull(data.GetArray());
}));
}
bool SendInternal(byte[] data, int length, bool rethrow, Socket socket,
GameEncryptionSession encryption, bool server)
{
return(RunGuarded(rethrow, server, () =>
{
if (encryption != null)
{
lock (encryption)
encryption.Encrypt(data, 0, length);
}
lock (socket)
socket.SendFull(data, 0, length);
}));
}
void DisconnectInternal()
{
Proxy.RemoveClient(this);
_disconnected = true;
_serverSocket.SafeClose();
_clientSocket.SafeClose();
lock (_encryptionLock)
{
_clientEncryption.Dispose();
_clientEncryption = null;
_serverEncryption.Dispose();
_serverEncryption = null;
}
Proxy.InvokeDisconnected(this);
}
void OnConnect(object sender, SocketAsyncEventArgs args)
{
var error = args.SocketError;
args.Completed -= OnConnect;
Proxy.ArgsPool.TryPut(args);
if (error != SocketError.Success && error != SocketError.OperationAborted)
{
DisconnectInternal();
_log.Error("Could not connect to {0} ({1}) for client {2}: {3}", Proxy.Info.Name,
Proxy.Info.RealEndPoint, EndPoint, error);
return;
}
_log.Info("Connected to {0} ({1}) for client {2}", Proxy.Info.Name,
Proxy.Info.RealEndPoint, EndPoint);
byte[] ckey1;
byte[] ckey2;
byte[] skey1;
byte[] skey2;
try
{
var magic = ReceiveFromServerInternal(_magic.Length);
SendToClientInternal(magic, true);
if (!magic.SequenceEqual(_magic))
{
DisconnectInternal();
_log.Error("Disconnected client {0} from {1} due to incorrect magic bytes: {2}",
EndPoint, Proxy.Info.Name, magic.Aggregate("0x", (acc, x) => acc + x.ToString("X2")));
return;
}
ckey1 = ReceiveFromClientInternal(GameEncryptionSession.KeySize);
SendToServerInternal(ckey1, true);
skey1 = ReceiveFromServerInternal(GameEncryptionSession.KeySize);
SendToClientInternal(skey1, true);
ckey2 = ReceiveFromClientInternal(GameEncryptionSession.KeySize);
SendToServerInternal(ckey2, true);
skey2 = ReceiveFromServerInternal(GameEncryptionSession.KeySize);
SendToClientInternal(skey2, true);
}
catch (SocketDisconnectedException)
{
// Normal disconnection.
Disconnect();
return;
}
catch (Exception e) when(IsSocketException(e))
{
// The client is already disconnected.
return;
}
_clientEncryption = new GameEncryptionSession(Direction.ClientToServer, ckey1, ckey2, skey1, skey2);
_serverEncryption = new GameEncryptionSession(Direction.ServerToClient, ckey1, ckey2, skey1, skey2);
_log.Info("Established encrypted session for client {0}", EndPoint);
Receive(Direction.ClientToServer, null, null, null, null, false);
Receive(Direction.ServerToClient, null, null, null, null, false);
Proxy.InvokeConnected(this);
}
