Fix weird session bugs

blokk-api/src/main/kotlin/space/blokk/net/DisconnectedCancellationException.kt

@@ -2,4 +2,4 @@ package space.blokk.net
 
 import java.util.concurrent.CancellationException
 
-class DisconnectedCancellationException(val reason: String? = null) : CancellationException("The connection was closed")
+class DisconnectedCancellationException : CancellationException("The player disconnected")

blokk-api/src/main/kotlin/space/blokk/net/Session.kt

@@ -1,10 +1,8 @@
 package space.blokk.net
 
 import io.netty.buffer.ByteBuf
-import kotlinx.coroutines.CoroutineScope
 import space.blokk.chat.TextComponent
 import space.blokk.event.EventBusWrapper
-import space.blokk.net.event.SessionEvent
 import space.blokk.net.packet.OutgoingPacket
 import space.blokk.net.packet.Protocol
 import space.blokk.player.GameMode
@@ -83,7 +81,7 @@ abstract class Session {
         class Joining(override val player: Player) : State(), WithPlayer
         class Playing(override val player: Player) : State(), WithPlayer
 
-        class Disconnected(val reason: String?) : State()
+        object Disconnected : State()
 
         inline fun <reified T : State> getOrFail(): T =
             if (this is T) this
@@ -99,12 +97,11 @@ abstract class Session {
      * Closes the connection with the client.
      *
      * @param reason The message shown to the player. Only used if [currentProtocol] is `LOGIN` or `PLAY`.
-     * @param loggableReason A short, loggable representation of [reason]. Not shown to the player, except
+     * @param internalReason A short, loggable representation of [reason] only shown to the player in development mode.
-     * in development mode.
      */
     abstract suspend fun disconnect(
         reason: TextComponent = TextComponent of "Disconnected.",
-        loggableReason: String = reason.text
+        internalReason: String? = null
     )
 
     /**

blokk-api/src/main/kotlin/space/blokk/util/CoroutineContextSupervisorChild.kt

@@ -0,0 +1,10 @@
+package space.blokk.util
+
+import kotlinx.coroutines.CoroutineName
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.SupervisorJob
+import kotlinx.coroutines.job
+import space.blokk.Blokk
+import kotlin.coroutines.CoroutineContext
+
+fun CoroutineContext.supervisorChild(name: String) = this + CoroutineName(name) + SupervisorJob(this.job)

blokk-api/src/main/kotlin/space/blokk/world/Chunk.kt

@@ -5,6 +5,7 @@ import kotlinx.coroutines.Job
 import kotlinx.coroutines.SupervisorJob
 import space.blokk.Blokk
 import space.blokk.player.Player
+import space.blokk.util.supervisorChild
 import kotlin.coroutines.CoroutineContext
 import kotlin.math.floor
 
@@ -41,8 +42,7 @@ abstract class Chunk(
      *
      * Is cancelled when the chunk is unloaded.
      */
-    val coroutineContext: CoroutineContext =
+    val coroutineContext: CoroutineContext = world.coroutineContext.supervisorChild(identifier)
-        world.coroutineContext + CoroutineName(identifier) + SupervisorJob(world.coroutineContext[Job])
 
     /**
      * A list of all players who have locked this chunk.

blokk-api/src/main/kotlin/space/blokk/world/World.kt

@@ -1,8 +1,10 @@
 package space.blokk.world
 
 import kotlinx.coroutines.*
+import space.blokk.Blokk
 import space.blokk.entity.Entity
 import space.blokk.util.newSingleThreadDispatcher
+import space.blokk.util.supervisorChild
 import java.util.*
 import kotlin.coroutines.CoroutineContext
 
@@ -18,8 +20,7 @@ abstract class World(val uuid: UUID) {
      *
      * Is cancelled when the world is unloaded.
      */
-    val coroutineContext: CoroutineContext =
+    val coroutineContext: CoroutineContext = Blokk.coroutineContext.supervisorChild(identifier) + threadExecutor
-        CoroutineName(identifier) + SupervisorJob() + threadExecutor
 
     abstract val dimension: Dimension
     abstract val loadedChunks: Map<Chunk.Key, Chunk>

blokk-packet-codecs/src/main/kotlin/space/blokk/net/packet/play/PlayProtocol.kt

@@ -19,6 +19,7 @@ object PlayProtocol : Protocol(
     PlayerInfoPacketCodec,
     PlayerPositionAndLookPacketCodec,
     ServerDifficultyPacketCodec,
+    SetCompassTargetPacketCodec,
     SetSelectedHotbarSlotPacketCodec,
     TagsPacketCodec,
     UpdateViewPositionPacketCodec

blokk-server/src/main/kotlin/space/blokk/BlokkServer.kt

@@ -3,10 +3,7 @@ package space.blokk
 import com.sksamuel.hoplite.ConfigFilePropertySource
 import com.sksamuel.hoplite.ConfigLoader
 import com.sksamuel.hoplite.ConfigSource
-import kotlinx.coroutines.CoroutineName
+import kotlinx.coroutines.*
-import kotlinx.coroutines.SupervisorJob
-import kotlinx.coroutines.asCoroutineDispatcher
-import kotlinx.coroutines.runBlocking
 import space.blokk.command.Command
 import space.blokk.config.BlokkConfig
 import space.blokk.event.BlokkEventBus
@@ -46,7 +43,14 @@ class BlokkServer internal constructor() : Server {
     val x509EncodedPublicKey: ByteArray = EncryptionUtils.generateX509Key(keyPair.public).encoded
 
     override val coroutineContext: CoroutineContext =
-        CoroutineName("Server") + Executors.newSingleThreadExecutor().asCoroutineDispatcher() + SupervisorJob()
+        CoroutineName("Server") + SupervisorJob() +
+                Executors.newSingleThreadExecutor { r -> Thread(r, "server") }.asCoroutineDispatcher()
+
+    init {
+        coroutineContext.job.invokeOnCompletion {
+            println(it)
+        }
+    }
 
     override val sessions by socketServer::sessions
     override val players get() = sessions.mapNotNull { it.player }

blokk-server/src/main/kotlin/space/blokk/config/BlokkConfig.kt

@@ -11,5 +11,6 @@ data class BlokkConfig(
     val developmentMode: Boolean,
     val minLogLevel: Logger.Level,
     val packetCompressionThreshold: Int,
-    val timeout: Duration
+    val timeout: Duration,
+    val packetsBufferSize: Int
 )

blokk-server/src/main/kotlin/space/blokk/event/BlokkEventBus.kt

@@ -11,7 +11,7 @@ import kotlin.reflect.KClass
 import kotlin.system.measureTimeMillis
 
 class BlokkEventBus(private val developmentMode: Boolean) : EventBus() {
-    private val logger = Logger("EventBus", false)
+    private val logger = Logger("EventBus")
 
     /**
      * Invokes all previously registered event handlers sorted by their handlerPosition.

blokk-server/src/main/kotlin/space/blokk/net/BlokkChannelInitializer.kt

@@ -1,31 +1,22 @@
 package space.blokk.net
 
-import io.netty.channel.Channel
+import io.netty.channel.*
-import io.netty.channel.ChannelException
-import io.netty.channel.ChannelInitializer
-import io.netty.channel.ChannelOption
 import io.netty.handler.timeout.IdleStateHandler
+import space.blokk.BlokkServer
 
-class BlokkChannelInitializer(private val blokkSocketServer: BlokkSocketServer) : ChannelInitializer<Channel>() {
+class BlokkChannelInitializer(private val server: BlokkServer) : ChannelInitializer<Channel>() {
     override fun initChannel(channel: Channel) {
         if (!ipTOSFailed) try {
             channel.config().setOption(ChannelOption.IP_TOS, 0x18)
         } catch (e: ChannelException) {
             ipTOSFailed = true
-            blokkSocketServer.server.logger warn "Your OS does not support IP type of service"
+            server.logger warn "Your OS does not support IP type of service"
         }
 
-        val session = BlokkSession(channel, blokkSocketServer.server)
+        channel.pipeline().addLast("framing", FramingCodec(server))
-
-        channel.pipeline()
-            .addLast("idle", IdleStateHandler(20, 15, 0))
-            .addLast("framing", FramingCodec())
-            .addLast("packets", PacketMessageCodec(session))
-            .addLast("handler", PacketMessageHandler(session))
     }
 
     companion object {
-        @Volatile
         private var ipTOSFailed = false
     }
 }

blokk-server/src/main/kotlin/space/blokk/net/BlokkSession.kt

@@ -1,47 +1,43 @@
 package space.blokk.net
 
 import io.netty.buffer.ByteBuf
-import io.netty.channel.Channel
 import kotlinx.coroutines.*
+import kotlinx.coroutines.channels.Channel
 import space.blokk.BlokkServer
 import space.blokk.chat.ChatColor
 import space.blokk.chat.ChatComponent
 import space.blokk.chat.TextComponent
 import space.blokk.event.*
 import space.blokk.logging.Logger
-import space.blokk.net.Session.State
+import space.blokk.net.MinecraftProtocolDataTypes.readVarInt
-import space.blokk.net.event.ClientBrandReceivedEvent
 import space.blokk.net.event.PacketReceivedEvent
 import space.blokk.net.event.PacketSendEvent
-import space.blokk.net.event.SessionEvent
 import space.blokk.net.packet.IncomingPacket
 import space.blokk.net.packet.OutgoingPacket
-import space.blokk.net.packet.Packet
 import space.blokk.net.packet.Protocol
 import space.blokk.net.packet.handshaking.HandshakingProtocol
 import space.blokk.net.packet.login.LoginProtocol
-import space.blokk.net.packet.play.IncomingKeepAlivePacket
 import space.blokk.net.packet.play.OutgoingKeepAlivePacket
 import space.blokk.net.packet.play.OutgoingPluginMessagePacket
 import space.blokk.net.packet.play.PlayProtocol
 import space.blokk.net.packet.status.StatusProtocol
 import space.blokk.server.event.SessionInitializedEvent
 import space.blokk.util.awaitSuspending
+import space.blokk.util.supervisorChild
+import java.io.IOException
 import java.net.InetAddress
 import java.net.InetSocketAddress
 import javax.crypto.SecretKey
 import kotlin.coroutines.CoroutineContext
 import kotlin.properties.Delegates
 
-class BlokkSession(private val channel: Channel, val server: BlokkServer) : Session() {
+class BlokkSession(private val channel: io.netty.channel.Channel, val server: BlokkServer) : Session() {
     override val address: InetAddress = (channel.remoteAddress() as InetSocketAddress).address
 
-    private val identifier = "BlokkSession(${address.hostAddress})"
+    private val identifier = "BlokkSession(${address.hostAddress})" + System.identityHashCode(this)
     val logger = Logger(identifier)
 
-    override val coroutineContext: CoroutineContext =
+    override val coroutineContext: CoroutineContext = server.coroutineContext.supervisorChild(identifier)
-        CoroutineName(identifier) + Dispatchers.Unconfined + SupervisorJob()
-
     val scope = CoroutineScope(coroutineContext)
 
     override var brand: String? = null
@@ -67,40 +63,96 @@ class BlokkSession(private val channel: Channel, val server: BlokkServer) : Sess
             is State.Disconnected -> null
         }
 
-    private var disconnectReason: String? = null
+    private var packetsChannel: Channel<IncomingPacket>? = null
+    private val packetDataChannel: Channel<ByteBuf> = Channel(Channel.UNLIMITED)
+
+    fun launchPacketsChannelWorker() {
+        val channel = Channel<IncomingPacket>(Channel.UNLIMITED)
+        packetsChannel = channel
+
+        scope.launch {
+            for (packet in channel) {
+                handlePacket(packet)
+            }
+        }
+    }
+
+    private suspend fun handlePacket(packet: IncomingPacket) {
+        logger.trace { "Packet received: $packet" }
+
+        server.eventBus.emit(PacketReceivedEvent(this@BlokkSession, packet)).ifNotCancelled {
+            SessionPacketReceivedEventHandler.handle(this@BlokkSession, packet)
+        }
+    }
+
+    init {
+        logger trace "Created"
+
+        scope.launch {
+            for (data in packetDataChannel) {
+                val packetID = data.readVarInt()
+                val codec = currentProtocol!!.incomingPacketCodecsByID[packetID]
+
+                if (codec == null) {
+                    val message = "Client sent an unknown packet (ID: $packetID)"
 
-    override suspend fun disconnect(reason: TextComponent, loggableReason: String) {
-        fun getReason() =
                     if (server.config.developmentMode) {
+                        logger warn "$message. This will cause the client to disconnect in production mode."
+                        continue
+                    } else throw IOException(message)
+                }
+
+                val packet = codec.decode(data)
+
+                if (packetsChannel != null) {
+                    // The protocol will not change anymore, so we can safely decode all packets with the current one
+                    if (!packetsChannel!!.offer(packet)) {
+                        logger.warn("The packet buffer is full (size: ${server.config.packetsBufferSize})")
+                        disconnect(internalReason = "You sent more packets than the packet buffer can handle")
+                    }
+                } else {
+                    // The protocol could change because of this packet, so we must wait
+                    handlePacket(packet)
+                }
+            }
+        }
+    }
+
+    override suspend fun disconnect(reason: TextComponent, internalReason: String?) {
+        if (currentProtocol == LoginProtocol || currentProtocol == PlayProtocol) {
+            logger info "Disconnected." + (internalReason?.let { " Internal reason: $it" } ?: "")
+
+            val finalReason = if (server.config.developmentMode && internalReason != null) {
                 val additional = listOf<ChatComponent>(
                     TextComponent(
                         "\n\nLogged reason (only shown in development mode): \n",
                         color = ChatColor.GRAY
                     ),
-                    TextComponent.of(loggableReason)
+                    TextComponent of internalReason
                 )
 
                 reason.copy(extra = reason.extra + additional)
             } else reason
 
-        disconnectReason = loggableReason
-
             when (currentProtocol) {
-            LoginProtocol -> send(space.blokk.net.packet.login.DisconnectPacket(getReason()))
+                LoginProtocol -> send(space.blokk.net.packet.login.DisconnectPacket(finalReason))
-            PlayProtocol -> send(space.blokk.net.packet.play.DisconnectPacket(getReason()))
+                PlayProtocol -> send(space.blokk.net.packet.play.DisconnectPacket(finalReason))
+            }
         }
 
+        onDisconnect(true)
         channel.close()
     }
 
     var lastKeepAlivePacketTimestamp by Delegates.notNull<Long>()
     lateinit var keepAliveDisconnectJob: Job
 
-    fun scheduleKeepAlivePacket() {
+    fun scheduleKeepAlivePacket(isFirst: Boolean = false) {
-        val timeSinceLastPacket = (System.currentTimeMillis() - lastKeepAlivePacketTimestamp).toInt()
-
         scope.launch {
+            if (!isFirst) {
+                val timeSinceLastPacket = (System.currentTimeMillis() - lastKeepAlivePacketTimestamp).toInt()
                 delay(KEEP_ALIVE_PACKET_INTERVAL.toLong() - timeSinceLastPacket)
+            }
 
             lastKeepAlivePacketTimestamp = System.currentTimeMillis()
             send(OutgoingKeepAlivePacket(lastKeepAlivePacketTimestamp))
@@ -120,41 +172,35 @@ class BlokkSession(private val channel: Channel, val server: BlokkServer) : Sess
 
     fun onConnect() = scope.launch {
         logger trace "Connected"
+        state = State.WaitingForHandshake
         if (server.eventBus.emit(SessionInitializedEvent(this@BlokkSession)).cancelled) channel.close()
         else server.sessions.add(this@BlokkSession)
     }
 
-    fun onDisconnect() {
+    fun onDisconnect(expected: Boolean) {
-        if (state is State.Disconnected) return
+        if (state == State.Disconnected) return
-        val reason = disconnectReason
+        if (!expected && currentProtocol != HandshakingProtocol && currentProtocol != StatusProtocol)
+            logger trace "The client disconnected unexpectedly"
 
-        logger.trace {
+        val closeException = DisconnectedCancellationException()
-            val message = "Disconnected."
-            if (reason != null) "$message Reason: $reason"
-            else message
-        }
-
-        coroutineContext.cancel(DisconnectedCancellationException(reason))
-        state = State.Disconnected(reason)
 
+        state = State.Disconnected
         server.sessions.remove(this)
+
+        packetDataChannel.close(closeException)
+        packetsChannel?.close(closeException)
+
+        coroutineContext.cancel(closeException)
     }
 
-    fun onPacketReceived(packet: IncomingPacket) {
+    fun onPacketDataReceived(packetData: ByteBuf) {
-        logger.trace { "Packet received: $packet" }
+        packetDataChannel.offer(packetData)
-
-        scope.launch {
-            server.eventBus.emit(PacketReceivedEvent(this@BlokkSession, packet)).ifNotCancelled {
-                SessionPacketReceivedEventHandler.handle(this@BlokkSession, packet)
-            }
-        }
     }
 
     fun failBecauseOfClient(message: String) {
-        val messageGetter = { "A connection error caused by the client occurred: $message" }
+        val messageGetter = { "The client caused a connection error: $message" }
         if (server.config.silentNonServerErrors) logger debug messageGetter else logger error messageGetter
-        channel.close()
+        onDisconnect(true)
-        onDisconnect()
     }
 
     fun enableEncryptionCodec(key: SecretKey) {
@@ -166,6 +212,7 @@ class BlokkSession(private val channel: Channel, val server: BlokkServer) : Sess
     fun enableCompressionCodec() {
         logger trace "Enabling compression codec"
         if (channel.pipeline().get("compression") != null) return
+
         channel.pipeline()
             .addAfter("framing", "compression", CompressionCodec(server.config.packetCompressionThreshold))
     }
@@ -174,9 +221,9 @@ class BlokkSession(private val channel: Channel, val server: BlokkServer) : Sess
         if (state is State.Disconnected) throw IllegalStateException("The session is not active anymore")
 
         logger.trace { "Sending packet: $packet" }
-        server.eventBus.emit(PacketSendEvent(this@BlokkSession, packet)).ifNotCancelled {
+        server.eventBus.emit(PacketSendEvent(this, packet)).ifNotCancelled {
             try {
-                channel.writeAndFlush(OutgoingPacketMessage(this@BlokkSession, it.packet)).awaitSuspending()
+                channel.writeAndFlush(it.packet).awaitSuspending()
             } catch (t: Throwable) {
                 if (!channel.isActive) return
                 logger.error("Sending packet failed", t)

blokk-server/src/main/kotlin/space/blokk/net/BlokkSocketServer.kt

@@ -14,9 +14,7 @@ import space.blokk.BlokkServer
 import space.blokk.logging.Logger
 import java.util.concurrent.CopyOnWriteArraySet
 
-class BlokkSocketServer(val server: BlokkServer) {
+class BlokkSocketServer(private val server: BlokkServer) {
-    private val logger = Logger("BlokkSocketServer")
-
     private val bossGroup = createEventLoopGroup()
     private val workerGroup = createEventLoopGroup()
     private val bootstrap: ServerBootstrap = ServerBootstrap()
@@ -30,7 +28,7 @@ class BlokkSocketServer(val server: BlokkServer) {
         )
         .childOption(ChannelOption.SO_KEEPALIVE, true)
         .childOption(ChannelOption.TCP_NODELAY, true)
-        .childHandler(BlokkChannelInitializer(this))
+        .childHandler(BlokkChannelInitializer(server))
 
     internal val sessions: MutableSet<BlokkSession> = CopyOnWriteArraySet()
 

blokk-server/src/main/kotlin/space/blokk/net/FramingCodec.kt

@@ -3,13 +3,23 @@ package space.blokk.net
 import io.netty.buffer.ByteBuf
 import io.netty.channel.ChannelHandlerContext
 import io.netty.handler.codec.ByteToMessageCodec
+import space.blokk.BlokkServer
 import space.blokk.net.MinecraftProtocolDataTypes.readVarInt
 import space.blokk.net.MinecraftProtocolDataTypes.varIntReadable
 import space.blokk.net.MinecraftProtocolDataTypes.writeVarInt
 
-class FramingCodec : ByteToMessageCodec<ByteBuf>() {
+class FramingCodec(private val server: BlokkServer) : ByteToMessageCodec<ByteBuf>() {
     private var currentLength: Int? = null
 
+    override fun channelActive(ctx: ChannelHandlerContext) {
+        val session = BlokkSession(ctx.channel(), server)
+
+        ctx.channel().pipeline()
+            .addLast("packets", PacketMessageDuplexHandler(session))
+
+        ctx.fireChannelActive()
+    }
+
     override fun encode(ctx: ChannelHandlerContext, msg: ByteBuf, out: ByteBuf) {
         out.writeVarInt(msg.readableBytes())
         msg.readerIndex(0)

blokk-server/src/main/kotlin/space/blokk/net/LoginAndJoinProcedure.kt

@@ -35,6 +35,7 @@ class LoginAndJoinProcedure(val session: BlokkSession) {
             val uuid = UUID.nameUUIDFromBytes("OfflinePlayer:${packet.username}".toByteArray())
             session.send(LoginSuccessPacket(uuid, packet.username))
             session.state = Session.State.LoginSucceeded(packet.username, uuid)
+            session.launchPacketsChannelWorker()
 
             afterLogin()
         }
@@ -86,7 +87,7 @@ class LoginAndJoinProcedure(val session: BlokkSession) {
             event.cancelled -> session.disconnect()
             initialWorldAndLocation == null -> {
                 session.logger warn "Could not join because no spawn location was set"
-                session.disconnect(loggableReason = "No spawn location set")
+                session.disconnect(internalReason = "No spawn location set")
             }
             else -> {
                 // TODO: Spawn the player entity
@@ -145,7 +146,7 @@ class LoginAndJoinProcedure(val session: BlokkSession) {
         val event = session.server.eventBus.emit(PlayerInitializationEvent(session, settings))
 
         event.ifCancelled {
-            session.disconnect(loggableReason = "PlayerInitializationEvent was cancelled")
+            session.disconnect(internalReason = "PlayerInitializationEvent was cancelled")
             return
         }
 
@@ -200,9 +201,7 @@ class LoginAndJoinProcedure(val session: BlokkSession) {
 
         session.send(UpdateViewPositionPacket(Chunk.Key.from(player.location.toVoxelLocation())))
 
-        session.lastKeepAlivePacketTimestamp = System.currentTimeMillis()
         session.scheduleKeepAlivePacket()
-
         player.sendChunksAndLight()
 
         // WorldBorder

blokk-server/src/main/kotlin/space/blokk/net/OutgoingPacketMessage.kt

@@ -1,17 +0,0 @@
-package space.blokk.net
-
-import io.netty.buffer.ByteBuf
-import space.blokk.net.packet.IncomingPacket
-import space.blokk.net.packet.OutgoingPacket
-import space.blokk.net.packet.OutgoingPacketCodec
-import space.blokk.net.packet.Packet
-
-abstract class PacketMessage<T : Packet>(val session: BlokkSession, val packet: T)
-
-class OutgoingPacketMessage<T : OutgoingPacket>(session: BlokkSession, packet: T) : PacketMessage<T>(session, packet) {
-    @Suppress("UNCHECKED_CAST")
-    val packetCodec = session.currentProtocol!!.getCodecByType(packet::class) as OutgoingPacketCodec<T>
-    fun encodePacket(dst: ByteBuf) = packetCodec.encode(packet, dst)
-}
-
-class IncomingPacketMessage<T : IncomingPacket>(session: BlokkSession, packet: T) : PacketMessage<T>(session, packet)

blokk-server/src/main/kotlin/space/blokk/net/PacketMessageCodec.kt

@@ -1,44 +0,0 @@
-package space.blokk.net
-
-import io.netty.buffer.ByteBuf
-import io.netty.channel.ChannelHandlerContext
-import io.netty.handler.codec.MessageToMessageCodec
-import space.blokk.net.MinecraftProtocolDataTypes.readVarInt
-import space.blokk.net.MinecraftProtocolDataTypes.writeVarInt
-import java.io.IOException
-
-class PacketMessageCodec(private val session: BlokkSession) : MessageToMessageCodec<ByteBuf, PacketMessage<*>>() {
-    override fun channelActive(ctx: ChannelHandlerContext) {
-        session.onConnect()
-    }
-
-    override fun channelInactive(ctx: ChannelHandlerContext) {
-        session.onDisconnect()
-    }
-
-    override fun encode(ctx: ChannelHandlerContext, msg: PacketMessage<*>, out: MutableList<Any>) {
-        if (msg !is OutgoingPacketMessage<*>) throw UnsupportedOperationException("Only outgoing packets can get encoded")
-
-        val dst = ctx.alloc().buffer()
-        dst.writeVarInt(msg.packetCodec.id)
-        msg.encodePacket(dst)
-        out.add(dst)
-    }
-
-    override fun decode(ctx: ChannelHandlerContext, msg: ByteBuf, out: MutableList<Any>) {
-        val packetID = msg.readVarInt()
-
-        val codec = session.currentProtocol!!.incomingPacketCodecsByID[packetID]
-
-        if (codec == null) {
-            val message = "Client sent an unknown packet (ID: $packetID)"
-            if (session.server.config.developmentMode)
-                session.logger warn "$message. This will cause the client to disconnect in production mode."
-            else throw IOException(message)
-        } else out.add(IncomingPacketMessage(session, codec.decode(msg)))
-    }
-
-    override fun exceptionCaught(ctx: ChannelHandlerContext, cause: Throwable) {
-        session.failBecauseOfClient("${cause::class.java.name}: ${cause.message}")
-    }
-}

blokk-server/src/main/kotlin/space/blokk/net/PacketMessageDuplexHandler.kt

@@ -0,0 +1,44 @@
+package space.blokk.net
+
+import io.netty.buffer.ByteBuf
+import io.netty.channel.ChannelDuplexHandler
+import io.netty.channel.ChannelHandlerContext
+import io.netty.channel.ChannelPromise
+import io.netty.handler.codec.MessageToMessageCodec
+import space.blokk.net.MinecraftProtocolDataTypes.readVarInt
+import space.blokk.net.MinecraftProtocolDataTypes.writeVarInt
+import space.blokk.net.packet.OutgoingPacket
+import space.blokk.net.packet.OutgoingPacketCodec
+import java.io.IOException
+
+class PacketMessageDuplexHandler(private val session: BlokkSession) : ChannelDuplexHandler() {
+    override fun channelActive(ctx: ChannelHandlerContext) {
+        session.onConnect()
+    }
+
+    override fun channelInactive(ctx: ChannelHandlerContext) {
+        session.onDisconnect(false)
+    }
+
+    override fun write(ctx: ChannelHandlerContext, msg: Any, promise: ChannelPromise) {
+        val packet = msg as OutgoingPacket
+
+        @Suppress("UNCHECKED_CAST")
+        val codec =
+            session.currentProtocol!!.getCodecByType(packet::class) as OutgoingPacketCodec<OutgoingPacket>
+
+        val dst = ctx.alloc().buffer()
+        dst.writeVarInt(codec.id)
+        codec.encode(packet, dst)
+        ctx.write(dst, promise)
+    }
+
+    override fun channelRead(ctx: ChannelHandlerContext, msg: Any) {
+        // TODO: Check if the ByteBuf needs to be released
+        session.onPacketDataReceived(msg as ByteBuf)
+    }
+
+    override fun exceptionCaught(ctx: ChannelHandlerContext, cause: Throwable) {
+        session.failBecauseOfClient("${cause::class.java.name}: ${cause.message}")
+    }
+}

blokk-server/src/main/kotlin/space/blokk/net/PacketMessageHandler.kt

@@ -1,13 +0,0 @@
-package space.blokk.net
-
-import io.netty.channel.ChannelHandlerContext
-import io.netty.channel.SimpleChannelInboundHandler
-import kotlinx.coroutines.launch
-import space.blokk.net.event.PacketReceivedEvent
-
-class PacketMessageHandler(private val session: BlokkSession) :
-    SimpleChannelInboundHandler<IncomingPacketMessage<*>>() {
-    override fun channelRead0(ctx: ChannelHandlerContext, msg: IncomingPacketMessage<*>) {
-        session.onPacketReceived(msg.packet)
-    }
-}

blokk-server/src/main/kotlin/space/blokk/net/packet/play/IncomingKeepAlivePacketHandler.kt

@@ -10,7 +10,7 @@ object IncomingKeepAlivePacketHandler : PacketReceivedEventHandler<IncomingKeepA
             session.keepAliveDisconnectJob.cancel()
             session.scheduleKeepAlivePacket()
         } else {
-            session.disconnect(loggableReason = "The ID of the last IncomingKeepAlive packet does not match the expected one.")
+            session.disconnect(internalReason = "The ID of the last IncomingKeepAlive packet does not match the expected one.")
         }
     }
 }

blokk-server/src/main/kotlin/space/blokk/net/packet/status/StatusProtocolHandler.kt

@@ -10,14 +10,15 @@ object StatusProtocolHandler : ProtocolPacketReceivedEventHandler(mapOf(
         val response = event.response
 
         when {
-            event.cancelled -> session.disconnect(loggableReason = "The ServerListInfoRequestEvent was cancelled.")
+            event.cancelled -> session.disconnect(internalReason = "The ServerListInfoRequestEvent was cancelled.")
             response == null ->
-                session.disconnect(loggableReason = "The response property of the ServerListInfoRequestEvent is null.")
+                session.disconnect(internalReason = "The response property of the ServerListInfoRequestEvent is null.")
 
             else -> session.send(ResponsePacket(response))
         }
     },
     PingPacket::class to PacketReceivedEventHandler.of<PingPacket> { session, packet ->
         session.send(PongPacket(packet.payload))
+        session.disconnect()
     }
 ))

blokk-server/src/main/resources/default-config.yml

@@ -6,3 +6,4 @@ developmentMode: false
 minLogLevel: INFO
 packetCompressionThreshold: 256
 timeout: 30s
+packetsBufferSize: 40

test-plugin/src/main/kotlin/space/blokk/testplugin/TestPlugin.kt

@@ -1,6 +1,9 @@
 package space.blokk.testplugin
 
 import space.blokk.Blokk
+import space.blokk.chat.TextComponent
+import space.blokk.net.ServerListInfo
+import space.blokk.net.event.ServerListInfoRequestEvent
 import space.blokk.net.event.SessionAfterLoginEvent
 import space.blokk.player.GameMode
 import space.blokk.plugin.Plugin
@@ -30,6 +33,10 @@ class TestPlugin: Plugin("Test", "1.0.0") {
 
         world.getVoxel(VoxelLocation.of(-1, 2, -1)).block = CraftingTable()
 
+        Blokk.eventBus.on<ServerListInfoRequestEvent> { event ->
+            event.response = ServerListInfo("1.16.4", 754, TextComponent of "Test", 10, 0, emptyList())
+        }
+
         Blokk.eventBus.on<SessionAfterLoginEvent> { event ->
             event.initialWorldAndLocation = WorldAndLocationWithRotation(
                 world,