Forward keep alive packets to the client (#1344)

* Forward keep alive packets to the client

Previously, MCProtocolLib (our Java protocol library) handled keep alive packets for us. This commit disables that option and 'forwards' the keep alive packets to the client, and sending the keep alive packet back once Bedrock sends us a ping response.

* Delete DataCache

* Update to latest MCProtocolLib

* Swap values around as a sanity check

connector/pom.xml

@@ -109,9 +109,9 @@
             <scope>compile</scope>
         </dependency>
         <dependency>
-            <groupId>com.github.GeyserMC</groupId>
+            <groupId>com.github.steveice10</groupId>
             <artifactId>mcprotocollib</artifactId>
-            <version>e4a3aa636a</version>
+            <version>976c2d0f89</version>
             <scope>compile</scope>
             <exclusions>
                 <exclusion>

connector/src/main/java/org/geysermc/connector/network/session/GeyserSession.java

@@ -28,6 +28,7 @@ package org.geysermc.connector.network.session;
 import com.github.steveice10.mc.auth.data.GameProfile;
 import com.github.steveice10.mc.auth.exception.request.InvalidCredentialsException;
 import com.github.steveice10.mc.auth.exception.request.RequestException;
+import com.github.steveice10.mc.protocol.MinecraftConstants;
 import com.github.steveice10.mc.protocol.MinecraftProtocol;
 import com.github.steveice10.mc.protocol.data.SubProtocol;
 import com.github.steveice10.mc.protocol.data.game.entity.player.GameMode;
@@ -117,8 +118,6 @@ public class GeyserSession implements CommandSender {
      */
     private final Object2LongMap<Vector3i> itemFrameCache = new Object2LongOpenHashMap<>();
 
-    private DataCache<Packet> javaPacketCache;
-
     @Setter
     private Vector2i lastChunkPosition = null;
     private int renderDistance;
@@ -176,6 +175,12 @@ public class GeyserSession implements CommandSender {
     @Setter
     private long lastWindowCloseTime = 0;
 
+    /**
+     * Saves the timestamp of the last keep alive packet
+     */
+    @Setter
+    private long lastKeepAliveTimestamp = 0;
+
     @Setter
     private VillagerTrade[] villagerTrades;
     @Setter
@@ -276,8 +281,6 @@ public class GeyserSession implements CommandSender {
         this.playerEntity = new PlayerEntity(new GameProfile(UUID.randomUUID(), "unknown"), 1, 1, Vector3f.ZERO, Vector3f.ZERO, Vector3f.ZERO);
         this.inventory = new PlayerInventory();
 
-        this.javaPacketCache = new DataCache<>();
-
         this.spawned = false;
         this.loggedIn = false;
 
@@ -384,6 +387,8 @@ public class GeyserSession implements CommandSender {
                 }
 
                 downstream = new Client(remoteServer.getAddress(), remoteServer.getPort(), protocol, new TcpSessionFactory());
+                // Let Geyser handle sending the keep alive
+                downstream.getSession().setFlag(MinecraftConstants.AUTOMATIC_KEEP_ALIVE_MANAGEMENT, false);
                 downstream.getSession().addListener(new SessionAdapter() {
                     @Override
                     public void packetSending(PacketSendingEvent event) {

connector/src/main/java/org/geysermc/connector/network/translators/PacketTranslatorRegistry.java

@@ -25,7 +25,6 @@
 
 package org.geysermc.connector.network.translators;
 
-import com.github.steveice10.mc.protocol.packet.ingame.server.ServerKeepAlivePacket;
 import com.github.steveice10.mc.protocol.packet.ingame.server.ServerPlayerListDataPacket;
 import com.github.steveice10.mc.protocol.packet.ingame.server.world.ServerUpdateLightPacket;
 import com.github.steveice10.packetlib.packet.Packet;
@@ -75,7 +74,6 @@ public class PacketTranslatorRegistry<T> {
             }
         }
 
-        IGNORED_PACKETS.add(ServerKeepAlivePacket.class); // Handled by MCProtocolLib
         IGNORED_PACKETS.add(ServerUpdateLightPacket.class); // Light is handled on Bedrock for us
         IGNORED_PACKETS.add(ServerPlayerListDataPacket.class); // Cant be implemented in bedrock
     }

connector/src/main/java/org/geysermc/connector/network/translators/bedrock/BedrockNetworkStackLatencyTranslator.java

@@ -23,15 +23,24 @@
  * @link https://github.com/GeyserMC/Geyser
  */
 
-package org.geysermc.connector.network.session.cache;
+package org.geysermc.connector.network.translators.bedrock;
 
-import lombok.Getter;
+import com.github.steveice10.mc.protocol.packet.ingame.client.ClientKeepAlivePacket;
+import com.nukkitx.protocol.bedrock.packet.NetworkStackLatencyPacket;
+import org.geysermc.connector.network.session.GeyserSession;
+import org.geysermc.connector.network.translators.PacketTranslator;
+import org.geysermc.connector.network.translators.Translator;
 
-import java.util.HashMap;
-import java.util.Map;
+/**
+ * Used to send the keep alive packet back to the server
+ */
+@Translator(packet = NetworkStackLatencyPacket.class)
+public class BedrockNetworkStackLatencyTranslator extends PacketTranslator<NetworkStackLatencyPacket> {
 
-public class DataCache<T> {
-
-    @Getter
-    private Map<String, T> cachedValues = new HashMap<String, T>();
+    @Override
+    public void translate(NetworkStackLatencyPacket packet, GeyserSession session) {
+        // The client sends a timestamp back but it's rounded and therefore unreliable when we need the exact number
+        ClientKeepAlivePacket keepAlivePacket = new ClientKeepAlivePacket(session.getLastKeepAliveTimestamp());
+        session.sendDownstreamPacket(keepAlivePacket);
+    }
 }

connector/src/main/java/org/geysermc/connector/network/translators/java/JavaKeepAliveTranslator.java

@@ -0,0 +1,48 @@
+/*
+ * Copyright (c) 2019-2020 GeyserMC. http://geysermc.org
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @author GeyserMC
+ * @link https://github.com/GeyserMC/Geyser
+ */
+
+package org.geysermc.connector.network.translators.java;
+
+import com.github.steveice10.mc.protocol.packet.ingame.server.ServerKeepAlivePacket;
+import com.nukkitx.protocol.bedrock.packet.NetworkStackLatencyPacket;
+import org.geysermc.connector.network.session.GeyserSession;
+import org.geysermc.connector.network.translators.PacketTranslator;
+import org.geysermc.connector.network.translators.Translator;
+
+/**
+ * Used to forward the keep alive packet to the client in order to get back a reliable ping.
+ */
+@Translator(packet = ServerKeepAlivePacket.class)
+public class JavaKeepAliveTranslator extends PacketTranslator<ServerKeepAlivePacket> {
+
+    @Override
+    public void translate(ServerKeepAlivePacket packet, GeyserSession session) {
+        session.setLastKeepAliveTimestamp(packet.getPingId());
+        NetworkStackLatencyPacket latencyPacket = new NetworkStackLatencyPacket();
+        latencyPacket.setFromServer(true);
+        latencyPacket.setTimestamp(packet.getPingId());
+        session.sendUpstreamPacket(latencyPacket);
+    }
+}