public static OperationStatus ValidateDataLength(NetConnection connection, int dataLength)
{
if (connection == null)
{
throw new ArgumentNullException(nameof(connection));
}
if (dataLength > NetManager.MaxClientPacketSize)
{
connection.Kick($"Packet data length {dataLength} exceeds {NetManager.MaxClientPacketSize}.");
return(OperationStatus.InvalidData);
}
return(OperationStatus.Done);
}
/// <summary>
/// Connection flow/lifetime:
/// Every connection begins in <see cref="EngageClientConnection"/>, where a loop reads
/// asynchrounsly from the client socket.
/// Successful reads get copied to the connection's receive buffer.
/// </summary>
public async Task EngageClientConnection(NetConnection connection, CancellationToken cancellationToken)
{
if (connection == null)
{
throw new ArgumentNullException(nameof(connection));
}
var readBuffer = new byte[1024 * 4]; // Clients don't really need a big read buffer.
var readMemory = readBuffer.AsMemory();
var socket = connection.Socket;
var receiveBuffer = connection.ReceiveBuffer;
var state = new ReceiveState(
connection,
new NetBinaryReader(receiveBuffer),
cancellationToken);
try
{
int read;
while ((read = await socket.ReceiveAsync(
readMemory, SocketFlags.None, state.CancellationToken).Unchain()) != 0)
{
// Insert received data into beginning of receive buffer.
var readSlice = readMemory.Slice(0, read);
receiveBuffer.Seek(0, SeekOrigin.End);
receiveBuffer.Write(readSlice.Span);
receiveBuffer.Seek(0, SeekOrigin.Begin);
connection.BytesReceived += readSlice.Length;
// We process by the message length (unless it's a legacy server list ping),
// so don't worry if we received parts of the next message.
OperationStatus handleStatus;
while ((handleStatus = HandlePacket(ref state)) == OperationStatus.Done)
{
if (!connection.IsAlive)
{
break;
}
}
if (!connection.IsAlive)
{
break;
}
receiveBuffer.TrimStart((int)receiveBuffer.Position);
}
}
catch (SocketException sockEx) when(sockEx.SocketErrorCode == SocketError.ConnectionReset)
{
// TODO: increment statistic?
}
catch (SocketException sockEx) when(sockEx.SocketErrorCode == SocketError.ConnectionAborted)
{
Console.WriteLine("Connection aborted for " + connection.RemoteEndPoint);
// TODO: increment statistic?
}
catch (Exception ex)
{
Console.WriteLine(ex);
connection.Kick(ex);
return;
}
connection.Close(immediate: false);
}