using System.Buffers.Binary; using System.Net.Mail; using System.Net.Sockets; using AscNet.Common.Util; using MessagePack; namespace AscNet.GameServer { public class Session { public readonly string id; public readonly TcpClient client; public readonly Logger c; private long lastPacketTime = DateTimeOffset.UtcNow.ToUnixTimeMilliseconds(); private ushort packetNo = 1; private readonly MessagePackSerializerOptions lz4Options = MessagePackSerializerOptions.Standard.WithCompression(MessagePackCompression.Lz4Block); public Session(string id, TcpClient tcpClient) { this.id = id; client = tcpClient; c = new(id, ConsoleColor.DarkGray); Task.Run(ClientLoop); } public async void ClientLoop() { NetworkStream stream = client.GetStream(); byte[] msg = new byte[1 << 16]; while (client.Connected) { try { Array.Clear(msg, 0, msg.Length); int len = stream.Read(msg, 0, msg.Length); if (len > 0) { lastPacketTime = DateTimeOffset.UtcNow.ToUnixTimeMilliseconds(); List packets = new(); int readbytes = 0; while (readbytes < len) { int packetLen = BinaryPrimitives.ReadInt32LittleEndian(msg.AsSpan()[readbytes..]); readbytes += 4; if (packetLen < 4) break; else { byte[] packet = GC.AllocateUninitializedArray(packetLen); Array.Copy(msg, readbytes, packet, 0, packetLen); readbytes += packetLen; Crypto.HaruCrypt.Decrypt(packet); try { packets.Add(MessagePackSerializer.Deserialize(packet, lz4Options)); } catch (Exception) { c.Error("Failed to deserialize packet: " + BitConverter.ToString(packet).Replace("-", "")); } } } foreach (var packet in packets) { switch (packet.Type) { case Packet.ContentType.Request: Packet.Request request = MessagePackSerializer.Deserialize(packet.Content); c.Log(request.Name); PacketFactory.GetPacketHandler(request.Name)?.Invoke(this, request.Content); break; case Packet.ContentType.Push: Packet.Push push = MessagePackSerializer.Deserialize(packet.Content); c.Log(push.Name); PacketFactory.GetPacketHandler(push.Name)?.Invoke(this, push.Content); break; case Packet.ContentType.Exception: Packet.Exception exception = MessagePackSerializer.Deserialize(packet.Content); c.Error($"Exception packet received: {exception.Code}, {exception.Message}"); break; default: c.Error($"Unknown packet received: {packet}"); break; } } } } catch (Exception) { break; } await Task.Delay(10); // 10 sec timeout if (DateTimeOffset.UtcNow.ToUnixTimeMilliseconds() - lastPacketTime > 10000) break; } DisconnectProtocol(); } public void SendPush(T push) { Packet.Push packet = new() { Name = typeof(T).Name, Content = MessagePackSerializer.Serialize(push) }; Send(new Packet() { No = packetNo, Type = Packet.ContentType.Push, Content = MessagePackSerializer.Serialize(packet) }); c.Log(packet.Name); packetNo++; } public void SendResponse(T response) { Packet.Response packet = new() { Id = 1, Name = typeof(T).Name, Content = MessagePackSerializer.Serialize(response) }; Send(new Packet() { No = packetNo, Type = Packet.ContentType.Response, Content = MessagePackSerializer.Serialize(packet) }); c.Log(packet.Name); packetNo++; } private void Send(Packet packet) { byte[] serializedPacket = MessagePackSerializer.Serialize(packet, lz4Options); Crypto.HaruCrypt.Encrypt(serializedPacket); byte[] sendBytes = GC.AllocateUninitializedArray(serializedPacket.Length + 4); BinaryPrimitives.WriteInt32LittleEndian(sendBytes.AsSpan()[0..4], serializedPacket.Length); Array.Copy(serializedPacket, 0, sendBytes, 4, serializedPacket.Length); client.GetStream().Write(sendBytes); } public void DisconnectProtocol() { if (Server.Instance.Sessions.GetValueOrDefault(id) is null) return; c.Warn($"{id} disconnected"); client.Close(); Server.Instance.Sessions.Remove(id); } } }