Support Minecraft 1.11/1.11.1+

src/main/java/com/velocitypowered/proxy/protocol/ProtocolConstants.java

@@ -3,11 +3,17 @@ package com.velocitypowered.proxy.protocol;
 import java.util.Arrays;
 
 public enum ProtocolConstants { ;
+    public static final int MINECRAFT_1_11 = 315;
+    public static final int MINECRAFT_1_11_1 = 316;
     public static final int MINECRAFT_1_12 = 335;
     public static final int MINECRAFT_1_12_1 = 338;
     public static final int MINECRAFT_1_12_2 = 340;
 
+    public static final int MINIMUM_VERSION_SUPPORTED = MINECRAFT_1_11;
+
     public static final int[] SUPPORTED_VERSIONS = new int[] {
+            MINECRAFT_1_11,
+            MINECRAFT_1_11_1,
             MINECRAFT_1_12,
             MINECRAFT_1_12_1,
             MINECRAFT_1_12_2

src/main/java/com/velocitypowered/proxy/protocol/StateRegistry.java

@@ -7,9 +7,7 @@ import io.netty.util.collection.IntObjectMap;
 import java.util.*;
 import java.util.function.Supplier;
 
-import static com.velocitypowered.proxy.protocol.ProtocolConstants.MINECRAFT_1_12;
+import static com.velocitypowered.proxy.protocol.ProtocolConstants.*;
-import static com.velocitypowered.proxy.protocol.ProtocolConstants.MINECRAFT_1_12_1;
-import static com.velocitypowered.proxy.protocol.ProtocolConstants.MINECRAFT_1_12_2;
 
 public enum StateRegistry {
     HANDSHAKE {
@@ -34,24 +32,32 @@ public enum StateRegistry {
     PLAY {
         {
             SERVERBOUND.register(Chat.class, Chat::new,
+                    map(0x02, MINECRAFT_1_11),
                     map(0x03, MINECRAFT_1_12),
                     map(0x02, MINECRAFT_1_12_2));
             SERVERBOUND.register(KeepAlive.class, KeepAlive::new,
+                    map(0x0B, MINECRAFT_1_11),
                     map(0x0C, MINECRAFT_1_12),
                     map(0x0B, MINECRAFT_1_12_1));
             SERVERBOUND.register(ClientSettings.class, ClientSettings::new,
+                    map(0x04, MINECRAFT_1_11),
                     map(0x05, MINECRAFT_1_12),
                     map(0x04, MINECRAFT_1_12_1));
 
             CLIENTBOUND.register(Chat.class, Chat::new,
+                    map(0x0F, MINECRAFT_1_11),
                     map(0x0F, MINECRAFT_1_12));
             CLIENTBOUND.register(Disconnect.class, Disconnect::new,
+                    map(0x1A, MINECRAFT_1_11),
                     map(0x1A, MINECRAFT_1_12));
             CLIENTBOUND.register(KeepAlive.class, KeepAlive::new,
+                    map(0x1F, MINECRAFT_1_11),
                     map(0x1F, MINECRAFT_1_12));
             CLIENTBOUND.register(JoinGame.class, JoinGame::new,
+                    map(0x23, MINECRAFT_1_11),
                     map(0x23, MINECRAFT_1_12));
             CLIENTBOUND.register(Respawn.class, Respawn::new,
+                    map(0x33, MINECRAFT_1_11),
                     map(0x34, MINECRAFT_1_12),
                     map(0x35, MINECRAFT_1_12_2));
         }
@@ -81,6 +87,7 @@ public enum StateRegistry {
         private static final IntObjectMap<int[]> LINKED_PROTOCOL_VERSIONS = new IntObjectHashMap<>();
 
         static {
+            LINKED_PROTOCOL_VERSIONS.put(MINECRAFT_1_11, new int[] { MINECRAFT_1_11_1 });
             LINKED_PROTOCOL_VERSIONS.put(MINECRAFT_1_12, new int[] { MINECRAFT_1_12_1 });
             LINKED_PROTOCOL_VERSIONS.put(MINECRAFT_1_12_1, new int[] { MINECRAFT_1_12_2 });
         }
@@ -204,6 +211,6 @@ public enum StateRegistry {
     }
 
     private static PacketMapping lowestVersion(int id) {
-        return new PacketMapping(id, MINECRAFT_1_12);
+        return new PacketMapping(id, MINECRAFT_1_11);
     }
 }

src/main/java/com/velocitypowered/proxy/protocol/netty/MinecraftDecoder.java

@@ -17,7 +17,7 @@ public class MinecraftDecoder extends MessageToMessageDecoder<ByteBuf> {
     public MinecraftDecoder(ProtocolConstants.Direction direction) {
         this.state = StateRegistry.HANDSHAKE;
         this.direction = Preconditions.checkNotNull(direction, "direction");
-        this.setProtocolVersion(ProtocolConstants.MINECRAFT_1_12);
+        this.setProtocolVersion(ProtocolConstants.MINIMUM_VERSION_SUPPORTED);
     }
 
     @Override

src/main/java/com/velocitypowered/proxy/protocol/netty/MinecraftEncoder.java

@@ -17,7 +17,7 @@ public class MinecraftEncoder extends MessageToByteEncoder<MinecraftPacket> {
     public MinecraftEncoder(ProtocolConstants.Direction direction) {
         this.state = StateRegistry.HANDSHAKE;
         this.direction = Preconditions.checkNotNull(direction, "direction");
-        this.setProtocolVersion(ProtocolConstants.MINECRAFT_1_12);
+        this.setProtocolVersion(ProtocolConstants.MINIMUM_VERSION_SUPPORTED);
     }
 
     @Override