Merge pull request #2695 from ViaVersion/legacy-injector-cleanup

Cleanup Bukkit/Sponge injectors

api/src/main/java/com/viaversion/viaversion/api/platform/ViaInjector.java

@@ -78,14 +78,18 @@ public interface ViaInjector {
      *
      * @return The name
      */
-    String getEncoderName();
+    default String getEncoderName() {
+        return "via-encoder";
+    }
 
     /**
      * Get the name of the decoder for then netty pipeline for this platform.
      *
      * @return The name
      */
-    String getDecoderName();
+    default String getDecoderName() {
+        return "via-decoder";
+    }
 
     /**
      * Get any relevant data for debugging injection issues.

bukkit/src/main/java/com/viaversion/viaversion/ViaVersionPlugin.java

@@ -84,14 +84,6 @@ public class ViaVersionPlugin extends JavaPlugin implements ViaPlatform<Player>
 
         // Check if we're using protocol support too
         protocolSupport = Bukkit.getPluginManager().getPlugin("ProtocolSupport") != null;
-        if (protocolSupport) {
-            getLogger().info("Hooking into ProtocolSupport, to prevent issues!");
-            try {
-                BukkitViaInjector.patchLists();
-            } catch (Exception e) {
-                e.printStackTrace();
-            }
-        }
     }
 
     @Override
@@ -124,7 +116,7 @@ public class ViaVersionPlugin extends JavaPlugin implements ViaPlatform<Player>
 
         // Generate classes needed (only works if it's compat or ps)
         ClassGenerator.generate();
-        lateBind = !BukkitViaInjector.isBinded();
+        lateBind = !((BukkitViaInjector) Via.getManager().getInjector()).isBinded();
 
         getLogger().info("ViaVersion " + getDescription().getVersion() + (compatSpigotBuild ? "compat" : "") + " is now loaded" + (lateBind ? ", waiting for boot. (late-bind)" : ", injecting!"));
         if (!lateBind) {

bukkit/src/main/java/com/viaversion/viaversion/bukkit/handlers/BukkitChannelInitializer.java

@@ -22,6 +22,7 @@ import com.viaversion.viaversion.bukkit.classgenerator.ClassGenerator;
 import com.viaversion.viaversion.bukkit.platform.PaperViaInjector;
 import com.viaversion.viaversion.classgenerator.generated.HandlerConstructor;
 import com.viaversion.viaversion.connection.UserConnectionImpl;
+import com.viaversion.viaversion.platform.WrappedChannelInitializer;
 import com.viaversion.viaversion.protocol.ProtocolPipelineImpl;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelInitializer;
@@ -30,21 +31,25 @@ import io.netty.handler.codec.MessageToByteEncoder;
 
 import java.lang.reflect.Method;
 
-public class BukkitChannelInitializer extends ChannelInitializer<Channel> {
+public class BukkitChannelInitializer extends ChannelInitializer<Channel> implements WrappedChannelInitializer {
 
+    private static final Method INIT_CHANNEL_METHOD;
     private final ChannelInitializer<Channel> original;
-    private Method method;
 
-    public BukkitChannelInitializer(ChannelInitializer<Channel> oldInit) {
+    static {
-        this.original = oldInit;
         try {
-            this.method = ChannelInitializer.class.getDeclaredMethod("initChannel", Channel.class);
+            INIT_CHANNEL_METHOD = ChannelInitializer.class.getDeclaredMethod("initChannel", Channel.class);
-            this.method.setAccessible(true);
+            INIT_CHANNEL_METHOD.setAccessible(true);
         } catch (NoSuchMethodException e) {
-            e.printStackTrace();
+            throw new RuntimeException(e);
         }
     }
 
+    public BukkitChannelInitializer(ChannelInitializer<Channel> oldInit) {
+        this.original = oldInit;
+    }
+
+    @Deprecated/*(forRemoval = true)*/
     public ChannelInitializer<Channel> getOriginal() {
         return original;
     }
@@ -52,7 +57,7 @@ public class BukkitChannelInitializer extends ChannelInitializer<Channel> {
     @Override
     protected void initChannel(Channel channel) throws Exception {
         // Add originals
-        this.method.invoke(this.original, channel);
+        INIT_CHANNEL_METHOD.invoke(this.original, channel);
         afterChannelInitialize(channel);
     }
 
@@ -72,4 +77,9 @@ public class BukkitChannelInitializer extends ChannelInitializer<Channel> {
         channel.pipeline().replace("encoder", "encoder", encoder);
         channel.pipeline().replace("decoder", "decoder", decoder);
     }
+
+    @Override
+    public ChannelInitializer<Channel> original() {
+        return original;
+    }
 }

bukkit/src/main/java/com/viaversion/viaversion/bukkit/platform/BukkitViaInjector.java

@@ -17,15 +17,10 @@
  */
 package com.viaversion.viaversion.bukkit.platform;
 
-import com.google.gson.JsonArray;
-import com.google.gson.JsonObject;
-import com.viaversion.viaversion.api.Via;
-import com.viaversion.viaversion.api.platform.ViaInjector;
 import com.viaversion.viaversion.bukkit.handlers.BukkitChannelInitializer;
 import com.viaversion.viaversion.bukkit.util.NMSUtil;
-import com.viaversion.viaversion.util.ConcurrentList;
+import com.viaversion.viaversion.platform.LegacyViaInjector;
-import com.viaversion.viaversion.util.ListWrapper;
+import com.viaversion.viaversion.platform.WrappedChannelInitializer;
-import com.viaversion.viaversion.util.Pair;
 import com.viaversion.viaversion.util.ReflectionUtil;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelFuture;
@@ -33,230 +28,88 @@ import io.netty.channel.ChannelHandler;
 import io.netty.channel.ChannelInitializer;
 import org.bukkit.Bukkit;
 import org.bukkit.plugin.PluginDescriptionFile;
+import org.checkerframework.checker.nullness.qual.Nullable;
 
 import java.lang.reflect.Field;
 import java.lang.reflect.Method;
-import java.util.ArrayList;
-import java.util.Collection;
 import java.util.List;
 
-//TODO screams
+public class BukkitViaInjector extends LegacyViaInjector {
-public class BukkitViaInjector implements ViaInjector {
-    private final List<ChannelFuture> injectedFutures = new ArrayList<>();
-    private final List<Pair<Field, Object>> injectedLists = new ArrayList<>();
-
     private boolean protocolLib;
 
     @Override
-    public void inject() throws Exception {
+    public void inject() throws ReflectiveOperationException {
         if (PaperViaInjector.PAPER_INJECTION_METHOD) {
             PaperViaInjector.setPaperChannelInitializeListener();
             return;
         }
 
-        try {
+        super.inject();
-            Object connection = getServerConnection();
-            if (connection == null) {
-                throw new Exception("We failed to find the core component 'ServerConnection', please file an issue on our GitHub.");
-            }
-            for (Field field : connection.getClass().getDeclaredFields()) {
-                field.setAccessible(true);
-                Object value = field.get(connection);
-                if (value instanceof List) {
-                    // Inject the list
-                    List wrapper = new ListWrapper((List) value) {
-                        @Override
-                        public void handleAdd(Object o) {
-                            if (o instanceof ChannelFuture) {
-                                try {
-                                    injectChannelFuture((ChannelFuture) o);
-                                } catch (Exception e) {
-                                    e.printStackTrace();
-                                }
-                            }
-                        }
-                    };
-                    injectedLists.add(new Pair<>(field, connection));
-                    field.set(connection, wrapper);
-                    // Iterate through current list
-                    synchronized (wrapper) {
-                        for (Object o : (List) value) {
-                            if (o instanceof ChannelFuture) {
-                                injectChannelFuture((ChannelFuture) o);
-                            } else {
-                                break; // not the right list.
-                            }
-                        }
-                    }
-                }
-            }
-
-        } catch (Exception e) {
-            Via.getPlatform().getLogger().severe("Unable to inject ViaVersion, please post these details on our GitHub and ensure you're using a compatible server version.");
-            throw e;
-        }
-    }
-
-    private void injectChannelFuture(ChannelFuture future) throws Exception {
-        try {
-            List<String> names = future.channel().pipeline().names();
-            ChannelHandler bootstrapAcceptor = null;
-            // Pick best
-            for (String name : names) {
-                ChannelHandler handler = future.channel().pipeline().get(name);
-                try {
-                    ReflectionUtil.get(handler, "childHandler", ChannelInitializer.class);
-                    bootstrapAcceptor = handler;
-                } catch (Exception e) {
-                    // Not this one
-                }
-            }
-            // Default to first (Also allows blame to work)
-            if (bootstrapAcceptor == null) {
-                bootstrapAcceptor = future.channel().pipeline().first();
-            }
-            try {
-                ChannelInitializer<Channel> oldInit = ReflectionUtil.get(bootstrapAcceptor, "childHandler", ChannelInitializer.class);
-                ChannelInitializer newInit = new BukkitChannelInitializer(oldInit);
-
-                ReflectionUtil.set(bootstrapAcceptor, "childHandler", newInit);
-                injectedFutures.add(future);
-            } catch (NoSuchFieldException e) {
-                // let's find who to blame!
-                ClassLoader cl = bootstrapAcceptor.getClass().getClassLoader();
-                if (cl.getClass().getName().equals("org.bukkit.plugin.java.PluginClassLoader")) {
-                    PluginDescriptionFile yaml = ReflectionUtil.get(cl, "description", PluginDescriptionFile.class);
-                    throw new Exception("Unable to inject, due to " + bootstrapAcceptor.getClass().getName() + ", try without the plugin " + yaml.getName() + "?");
-                } else {
-                    throw new Exception("Unable to find core component 'childHandler', please check your plugins. issue: " + bootstrapAcceptor.getClass().getName());
-                }
-
-            }
-        } catch (Exception e) {
-            Via.getPlatform().getLogger().severe("We failed to inject ViaVersion, have you got late-bind enabled with something else?");
-            throw e;
-        }
     }
 
     @Override
-    public void uninject() throws Exception {
+    public void uninject() throws ReflectiveOperationException {
-        // TODO: Uninject from players currently online to prevent protocol lib issues.
         if (PaperViaInjector.PAPER_INJECTION_METHOD) {
             PaperViaInjector.removePaperChannelInitializeListener();
             return;
         }
 
-        for (ChannelFuture future : injectedFutures) {
+        super.uninject();
-            List<String> names = future.channel().pipeline().names();
-            ChannelHandler bootstrapAcceptor = null;
-            // Pick best
-            for (String name : names) {
-                ChannelHandler handler = future.channel().pipeline().get(name);
-                try {
-                    ChannelInitializer<Channel> oldInit = ReflectionUtil.get(handler, "childHandler", ChannelInitializer.class);
-                    if (oldInit instanceof BukkitChannelInitializer) {
-                        bootstrapAcceptor = handler;
-                    }
-                } catch (Exception e) {
-                    // Not this one
-                }
-            }
-            // Default to first
-            if (bootstrapAcceptor == null) {
-                bootstrapAcceptor = future.channel().pipeline().first();
-            }
-
-            try {
-                ChannelInitializer<Channel> oldInit = ReflectionUtil.get(bootstrapAcceptor, "childHandler", ChannelInitializer.class);
-                if (oldInit instanceof BukkitChannelInitializer) {
-                    ReflectionUtil.set(bootstrapAcceptor, "childHandler", ((BukkitChannelInitializer) oldInit).getOriginal());
-                }
-            } catch (Exception e) {
-                Via.getPlatform().getLogger().severe("Failed to remove injection handler, reload won't work with connections, please reboot!");
-            }
-        }
-        injectedFutures.clear();
-
-        for (Pair<Field, Object> pair : injectedLists) {
-            try {
-                Object o = pair.key().get(pair.value());
-                if (o instanceof ListWrapper) {
-                    pair.key().set(pair.value(), ((ListWrapper) o).getOriginalList());
-                }
-            } catch (IllegalAccessException e) {
-                Via.getPlatform().getLogger().severe("Failed to remove injection, reload won't work with connections, please reboot!");
-            }
-        }
-
-        injectedLists.clear();
     }
 
     @Override
-    public boolean lateProtocolVersionSetting() {
+    public int getServerProtocolVersion() throws ReflectiveOperationException {
-        return true;
-    }
-
-    @Override
-    public int getServerProtocolVersion() throws Exception {
         if (PaperViaInjector.PAPER_PROTOCOL_METHOD) {
             //noinspection deprecation
             return Bukkit.getUnsafe().getProtocolVersion();
         }
 
-        try {
+        // Time to go on a journey! The protocol version is hidden inside an int in ServerPing.ServerData
-            // Grab a static instance of the server
+        // Grab a static instance of the server
-            Class<?> serverClazz = NMSUtil.nms("MinecraftServer", "net.minecraft.server.MinecraftServer");
+        Class<?> serverClazz = NMSUtil.nms("MinecraftServer", "net.minecraft.server.MinecraftServer");
-            Object server = ReflectionUtil.invokeStatic(serverClazz, "getServer");
+        Object server = ReflectionUtil.invokeStatic(serverClazz, "getServer");
 
-            // Grab the ping class and find the field to access it
+        // Grab the ping class and find the field to access it
-            Class<?> pingClazz = NMSUtil.nms(
+        Class<?> pingClazz = NMSUtil.nms(
-                    "ServerPing",
+                "ServerPing",
-                    "net.minecraft.network.protocol.status.ServerPing"
+                "net.minecraft.network.protocol.status.ServerPing"
-            );
+        );
-            Object ping = null;
+        Object ping = null;
-            // Search for ping method
+        for (Field field : serverClazz.getDeclaredFields()) {
-            for (Field f : serverClazz.getDeclaredFields()) {
+            if (field.getType() == pingClazz) {
-                if (f.getType() != null) {
+                field.setAccessible(true);
-                    if (f.getType().getSimpleName().equals("ServerPing")) {
+                ping = field.get(server);
-                        f.setAccessible(true);
+                break;
-                        ping = f.get(server);
-                    }
-                }
             }
-            if (ping != null) {
-                Object serverData = null;
-                for (Field f : pingClazz.getDeclaredFields()) {
-                    if (f.getType() != null) {
-                        if (f.getType().getSimpleName().endsWith("ServerData")) {
-                            f.setAccessible(true);
-                            serverData = f.get(ping);
-                        }
-                    }
-                }
-                if (serverData != null) {
-                    int protocolVersion = -1;
-                    for (Field f : serverData.getClass().getDeclaredFields()) {
-                        if (f.getType() != null) {
-                            if (f.getType() == int.class) {
-                                f.setAccessible(true);
-                                protocolVersion = (int) f.get(serverData);
-                            }
-                        }
-                    }
-                    if (protocolVersion != -1) {
-                        return protocolVersion;
-                    }
-                }
-            }
-        } catch (Exception e) {
-            throw new Exception("Failed to get server", e);
         }
-        throw new Exception("Failed to get server");
-    }
 
-    @Override
+        // Now get the ServerData inside ServerPing
-    public String getEncoderName() {
+        Class<?> serverDataClass = NMSUtil.nms(
-        return "encoder";
+                "ServerPing$ServerData",
+                "net.minecraft.network.protocol.status.ServerPing$ServerData"
+        );
+        Object serverData = null;
+        for (Field field : pingClazz.getDeclaredFields()) {
+            if (field.getType() == serverDataClass) {
+                field.setAccessible(true);
+                serverData = field.get(ping);
+                break;
+            }
+        }
+
+        // Get protocol version field
+        for (Field field : serverDataClass.getDeclaredFields()) {
+            if (field.getType() != int.class) {
+                continue;
+            }
+
+            field.setAccessible(true);
+            int protocolVersion = (int) field.get(serverData);
+            if (protocolVersion != -1) {
+                return protocolVersion;
+            }
+        }
+        throw new RuntimeException("Failed to get server");
     }
 
     @Override
@@ -264,135 +117,79 @@ public class BukkitViaInjector implements ViaInjector {
         return protocolLib ? "protocol_lib_decoder" : "decoder";
     }
 
-    public static Object getServerConnection() throws Exception {
+    @Override
-        Class<?> serverClazz = NMSUtil.nms(
+    protected @Nullable Object getServerConnection() throws ReflectiveOperationException {
+        Class<?> serverClass = NMSUtil.nms(
                 "MinecraftServer",
                 "net.minecraft.server.MinecraftServer"
         );
-        Object server = ReflectionUtil.invokeStatic(serverClazz, "getServer");
+        Class<?> connectionClass = NMSUtil.nms(
-        Object connection = null;
+                "ServerConnection",
-        for (Method m : serverClazz.getDeclaredMethods()) {
+                "net.minecraft.server.network.ServerConnection"
-            if (m.getReturnType() != null) {
+        );
-                if (m.getReturnType().getSimpleName().equals("ServerConnection")) {
+
-                    if (m.getParameterTypes().length == 0) {
+        Object server = ReflectionUtil.invokeStatic(serverClass, "getServer");
-                        connection = m.invoke(server);
+        for (Method method : serverClass.getDeclaredMethods()) {
-                    }
+            if (method.getReturnType() != connectionClass || method.getParameterTypes().length != 0) {
-                }
+                continue;
+            }
+
+            // We need the method that initiates the connection if not yet set
+            Object connection = method.invoke(server);
+            if (connection != null) {
+                return connection;
             }
         }
-        return connection;
+        return null;
     }
 
-    public static boolean isBinded() {
+    @Override
-        if (PaperViaInjector.PAPER_INJECTION_METHOD) return true;
+    protected WrappedChannelInitializer createChannelInitializer(ChannelInitializer<Channel> oldInitializer) {
+        return new BukkitChannelInitializer(oldInitializer);
+    }
+
+    @Override
+    protected void blame(ChannelHandler bootstrapAcceptor) throws ReflectiveOperationException {
+        // Let's find who to blame!
+        ClassLoader classLoader = bootstrapAcceptor.getClass().getClassLoader();
+        if (classLoader.getClass().getName().equals("org.bukkit.plugin.java.PluginClassLoader")) {
+            PluginDescriptionFile description = ReflectionUtil.get(classLoader, "description", PluginDescriptionFile.class);
+            throw new RuntimeException("Unable to inject, due to " + bootstrapAcceptor.getClass().getName() + ", try without the plugin " + description.getName() + "?");
+        } else {
+            throw new RuntimeException("Unable to find core component 'childHandler', please check your plugins. issue: " + bootstrapAcceptor.getClass().getName());
+        }
+    }
+
+    public boolean isBinded() {
+        if (PaperViaInjector.PAPER_INJECTION_METHOD) {
+            return true;
+        }
         try {
             Object connection = getServerConnection();
             if (connection == null) {
                 return false;
             }
+
             for (Field field : connection.getClass().getDeclaredFields()) {
+                if (!List.class.isAssignableFrom(field.getType())) {
+                    continue;
+                }
+
                 field.setAccessible(true);
-                final Object value = field.get(connection);
+                List<?> value = (List<?>) field.get(connection);
-                if (value instanceof List) {
+                // Check if the list has at least one element
-                    // Inject the list
+                synchronized (value) {
-                    synchronized (value) {
+                    if (!value.isEmpty() && value.get(0) instanceof ChannelFuture) {
-                        for (Object o : (List) value) {
+                        return true;
-                            if (o instanceof ChannelFuture) {
-                                return true;
-                            } else {
-                                break; // not the right list.
-                            }
-                        }
                     }
                 }
             }
-        } catch (Exception e) {
+        } catch (ReflectiveOperationException e) {
+            e.printStackTrace();
         }
         return false;
     }
 
-    @Override
-    public JsonObject getDump() {
-        JsonObject data = new JsonObject();
-
-        // Generate information about current injections
-        JsonArray injectedChannelInitializers = new JsonArray();
-        for (ChannelFuture cf : injectedFutures) {
-            JsonObject info = new JsonObject();
-            info.addProperty("futureClass", cf.getClass().getName());
-            info.addProperty("channelClass", cf.channel().getClass().getName());
-
-            // Get information about the pipes for this channel future
-            JsonArray pipeline = new JsonArray();
-            for (String pipeName : cf.channel().pipeline().names()) {
-                JsonObject pipe = new JsonObject();
-                pipe.addProperty("name", pipeName);
-                if (cf.channel().pipeline().get(pipeName) != null) {
-                    pipe.addProperty("class", cf.channel().pipeline().get(pipeName).getClass().getName());
-                    try {
-                        Object child = ReflectionUtil.get(cf.channel().pipeline().get(pipeName), "childHandler", ChannelInitializer.class);
-                        pipe.addProperty("childClass", child.getClass().getName());
-                        if (child instanceof BukkitChannelInitializer) {
-                            pipe.addProperty("oldInit", ((BukkitChannelInitializer) child).getOriginal().getClass().getName());
-                        }
-                    } catch (Exception e) {
-                        // Don't display
-                    }
-                }
-                // Add to the pipeline array
-                pipeline.add(pipe);
-            }
-            info.add("pipeline", pipeline);
-
-            // Add to the list
-            injectedChannelInitializers.add(info);
-        }
-        data.add("injectedChannelInitializers", injectedChannelInitializers);
-
-        // Generate information about lists we've injected into
-        JsonObject wrappedLists = new JsonObject();
-        JsonObject currentLists = new JsonObject();
-        try {
-            for (Pair<Field, Object> pair : injectedLists) {
-                Object list = pair.key().get(pair.value());
-                // Note down the current value (could be overridden by another plugin)
-                currentLists.addProperty(pair.key().getName(), list.getClass().getName());
-                // Also if it's not overridden we can display what's inside our list (possibly another plugin)
-                if (list instanceof ListWrapper) {
-                    wrappedLists.addProperty(pair.key().getName(), ((ListWrapper) list).getOriginalList().getClass().getName());
-                }
-            }
-            data.add("wrappedLists", wrappedLists);
-            data.add("currentLists", currentLists);
-        } catch (Exception e) {
-            // Ignored, fields won't be present
-        }
-
-        data.addProperty("binded", isBinded());
-        return data;
-    }
-
-    public static void patchLists() throws Exception {
-        if (PaperViaInjector.PAPER_INJECTION_METHOD) return;
-
-        Object connection = getServerConnection();
-        if (connection == null) {
-            Via.getPlatform().getLogger().warning("We failed to find the core component 'ServerConnection', please file an issue on our GitHub.");
-            return;
-        }
-
-        for (Field field : connection.getClass().getDeclaredFields()) {
-            field.setAccessible(true);
-            Object value = field.get(connection);
-            if (!(value instanceof List)) continue;
-            if (value instanceof ConcurrentList) continue;
-
-            ConcurrentList list = new ConcurrentList();
-            list.addAll((Collection) value);
-            field.set(connection, list);
-        }
-    }
-
     public void setProtocolLib(boolean protocolLib) {
         this.protocolLib = protocolLib;
     }

bungee/src/main/java/com/viaversion/viaversion/bungee/platform/BungeeViaInjector.java

@@ -80,16 +80,6 @@ public class BungeeViaInjector implements ViaInjector {
         return ReflectionUtil.getStatic(Class.forName("net.md_5.bungee.protocol.ProtocolConstants"), "SUPPORTED_VERSION_IDS", List.class);
     }
 
-    @Override
-    public String getEncoderName() {
-        return "via-encoder";
-    }
-
-    @Override
-    public String getDecoderName() {
-        return "via-decoder";
-    }
-
     private ChannelInitializer<Channel> getChannelInitializer() throws Exception {
         Class<?> pipelineUtils = Class.forName("net.md_5.bungee.netty.PipelineUtils");
         Field field = pipelineUtils.getDeclaredField("SERVER_CHILD");

common/src/main/java/com/viaversion/viaversion/platform/LegacyViaInjector.java

@@ -0,0 +1,264 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package com.viaversion.viaversion.platform;
+
+import com.google.gson.JsonArray;
+import com.google.gson.JsonObject;
+import com.viaversion.viaversion.api.Via;
+import com.viaversion.viaversion.api.platform.ViaInjector;
+import com.viaversion.viaversion.util.Pair;
+import com.viaversion.viaversion.util.ReflectionUtil;
+import com.viaversion.viaversion.util.SynchronizedListWrapper;
+import io.netty.channel.Channel;
+import io.netty.channel.ChannelFuture;
+import io.netty.channel.ChannelHandler;
+import io.netty.channel.ChannelInitializer;
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+import java.lang.reflect.Field;
+import java.util.ArrayList;
+import java.util.List;
+
+public abstract class LegacyViaInjector implements ViaInjector {
+    protected final List<ChannelFuture> injectedFutures = new ArrayList<>();
+    protected final List<Pair<Field, Object>> injectedLists = new ArrayList<>();
+
+    @Override
+    public void inject() throws ReflectiveOperationException {
+        Object connection = getServerConnection();
+        if (connection == null) {
+            throw new RuntimeException("Failed to find the core component 'ServerConnection'");
+        }
+
+        // Inject into channels list
+        for (Field field : connection.getClass().getDeclaredFields()) {
+            // Check for list with the correct generic type
+            if (!List.class.isAssignableFrom(field.getType()) || !field.getGenericType().getTypeName().contains(ChannelFuture.class.getName())) {
+                continue;
+            }
+
+            field.setAccessible(true);
+            List<ChannelFuture> list = (List<ChannelFuture>) field.get(connection);
+            List<ChannelFuture> wrappedList = new SynchronizedListWrapper(list, o -> {
+                // Inject newly added entries
+                try {
+                    injectChannelFuture((ChannelFuture) o);
+                } catch (ReflectiveOperationException e) {
+                    throw new RuntimeException(e);
+                }
+            });
+
+            // Synchronize over original list before setting the field
+            synchronized (list) {
+                // Iterate through current list
+                for (ChannelFuture future : list) {
+                    injectChannelFuture(future);
+                }
+
+                field.set(connection, wrappedList);
+            }
+
+            injectedLists.add(new Pair<>(field, connection));
+        }
+    }
+
+    private void injectChannelFuture(ChannelFuture future) throws ReflectiveOperationException {
+        List<String> names = future.channel().pipeline().names();
+        ChannelHandler bootstrapAcceptor = null;
+        // Find the right channelhandler
+        for (String name : names) {
+            ChannelHandler handler = future.channel().pipeline().get(name);
+            try {
+                ReflectionUtil.get(handler, "childHandler", ChannelInitializer.class);
+                bootstrapAcceptor = handler;
+                break;
+            } catch (ReflectiveOperationException ignored) {
+                // Not this one
+            }
+        }
+
+        if (bootstrapAcceptor == null) {
+            // Default to first (also allows blame to work)
+            bootstrapAcceptor = future.channel().pipeline().first();
+        }
+
+        try {
+            ChannelInitializer<Channel> oldInitializer = ReflectionUtil.get(bootstrapAcceptor, "childHandler", ChannelInitializer.class);
+            ReflectionUtil.set(bootstrapAcceptor, "childHandler", createChannelInitializer(oldInitializer));
+            injectedFutures.add(future);
+        } catch (NoSuchFieldException ignored) {
+            blame(bootstrapAcceptor);
+        }
+    }
+
+    @Override
+    public void uninject() throws ReflectiveOperationException {
+        //TODO uninject connections
+        for (ChannelFuture future : injectedFutures) {
+            List<String> names = future.channel().pipeline().names();
+            ChannelHandler bootstrapAcceptor = null;
+            // Pick best
+            for (String name : names) {
+                ChannelHandler handler = future.channel().pipeline().get(name);
+                try {
+                    if (ReflectionUtil.get(handler, "childHandler", ChannelInitializer.class) instanceof WrappedChannelInitializer) {
+                        bootstrapAcceptor = handler;
+                        break;
+                    }
+                } catch (ReflectiveOperationException ignored) {
+                }
+            }
+
+            if (bootstrapAcceptor == null) {
+                // Default to first
+                bootstrapAcceptor = future.channel().pipeline().first();
+            }
+
+            try {
+                ChannelInitializer<Channel> initializer = ReflectionUtil.get(bootstrapAcceptor, "childHandler", ChannelInitializer.class);
+                if (initializer instanceof WrappedChannelInitializer) {
+                    ReflectionUtil.set(bootstrapAcceptor, "childHandler", ((WrappedChannelInitializer) initializer).original());
+                }
+            } catch (Exception e) {
+                Via.getPlatform().getLogger().severe("Failed to remove injection handler, reload won't work with connections, please reboot!");
+                e.printStackTrace();
+            }
+        }
+
+        injectedFutures.clear();
+
+        for (Pair<Field, Object> pair : injectedLists) {
+            try {
+                Field field = pair.key();
+                Object o = field.get(pair.value());
+                if (o instanceof SynchronizedListWrapper) {
+                    List<ChannelFuture> originalList = ((SynchronizedListWrapper) o).originalList();
+                    synchronized (originalList) {
+                        field.set(pair.value(), originalList);
+                    }
+                }
+            } catch (ReflectiveOperationException e) {
+                Via.getPlatform().getLogger().severe("Failed to remove injection, reload won't work with connections, please reboot!");
+            }
+        }
+
+        injectedLists.clear();
+    }
+
+    @Override
+    public boolean lateProtocolVersionSetting() {
+        return true;
+    }
+
+    @Override
+    public JsonObject getDump() {
+        JsonObject data = new JsonObject();
+
+        // Generate information about current injections
+        JsonArray injectedChannelInitializers = new JsonArray();
+        data.add("injectedChannelInitializers", injectedChannelInitializers);
+        for (ChannelFuture future : injectedFutures) {
+            JsonObject futureInfo = new JsonObject();
+            injectedChannelInitializers.add(futureInfo);
+
+            futureInfo.addProperty("futureClass", future.getClass().getName());
+            futureInfo.addProperty("channelClass", future.channel().getClass().getName());
+
+            // Get information about the pipes for this channel future
+            JsonArray pipeline = new JsonArray();
+            futureInfo.add("pipeline", pipeline);
+            for (String pipeName : future.channel().pipeline().names()) {
+                JsonObject handlerInfo = new JsonObject();
+                pipeline.add(handlerInfo);
+
+                handlerInfo.addProperty("name", pipeName);
+                ChannelHandler channelHandler = future.channel().pipeline().get(pipeName);
+                if (channelHandler == null) {
+                    handlerInfo.addProperty("status", "INVALID");
+                    continue;
+                }
+
+                handlerInfo.addProperty("class", channelHandler.getClass().getName());
+                try {
+                    Object child = ReflectionUtil.get(channelHandler, "childHandler", ChannelInitializer.class);
+                    handlerInfo.addProperty("childClass", child.getClass().getName());
+                    if (child instanceof WrappedChannelInitializer) {
+                        handlerInfo.addProperty("oldInit", ((WrappedChannelInitializer) child).original().getClass().getName());
+                    }
+                } catch (ReflectiveOperationException ignored) {
+                    // Don't display
+                }
+            }
+        }
+
+        // Generate information about lists we've injected into
+        JsonObject wrappedLists = new JsonObject();
+        JsonObject currentLists = new JsonObject();
+        try {
+            for (Pair<Field, Object> pair : injectedLists) {
+                Field field = pair.key();
+                Object list = field.get(pair.value());
+                // Note down the current value (could be overridden by another plugin)
+                currentLists.addProperty(field.getName(), list.getClass().getName());
+                // Also, if it's not overridden we can display what's inside our list (possibly another plugin)
+                if (list instanceof SynchronizedListWrapper) {
+                    wrappedLists.addProperty(field.getName(), ((SynchronizedListWrapper) list).originalList().getClass().getName());
+                }
+            }
+            data.add("wrappedLists", wrappedLists);
+            data.add("currentLists", currentLists);
+        } catch (ReflectiveOperationException ignored) {
+            // Ignored, fields won't be present
+        }
+        return data;
+    }
+
+    @Override
+    public String getEncoderName() {
+        return "encoder";
+    }
+
+    @Override
+    public String getDecoderName() {
+        return "decoder";
+    }
+
+    /**
+     * Returns the Vanilla server connection object the channels to be injected should be searched in.
+     *
+     * @return server connection object, or null if failed
+     */
+    protected abstract @Nullable Object getServerConnection() throws ReflectiveOperationException;
+
+    /**
+     * Returns a new Via channel initializer wrapping the original one.
+     *
+     * @param oldInitializer original channel initializer
+     * @return wrapped Via channel initializer
+     */
+    protected abstract WrappedChannelInitializer createChannelInitializer(ChannelInitializer<Channel> oldInitializer);
+
+    /**
+     * Should throw a {@link RuntimeException} with information on what/who might have caused an issue.
+     * Called when injection fails.
+     *
+     * @param bootstrapAcceptor head channel handler to be used when blaming
+     * @throws ReflectiveOperationException during reflective operation
+     */
+    protected abstract void blame(ChannelHandler bootstrapAcceptor) throws ReflectiveOperationException;
+}

common/src/main/java/com/viaversion/viaversion/platform/WrappedChannelInitializer.java

@@ -0,0 +1,26 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package com.viaversion.viaversion.platform;
+
+import io.netty.channel.Channel;
+import io.netty.channel.ChannelInitializer;
+
+public interface WrappedChannelInitializer {
+
+    ChannelInitializer<Channel> original();
+}

common/src/main/java/com/viaversion/viaversion/util/ConcurrentList.java

@@ -1,283 +0,0 @@
-/*
- * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
- * Copyright (C) 2016-2021 ViaVersion and contributors
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
-package com.viaversion.viaversion.util;
-
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.Iterator;
-import java.util.List;
-import java.util.ListIterator;
-import java.util.NoSuchElementException;
-
-/**
- * Created by wea_ondara licensed under MIT
- * Same license as in LICENSE
- * <p>
- * Taken from:
- * https://github.com/weaondara/BungeePerms/blob/master/src/main/java/net/alpenblock/bungeeperms/util/ConcurrentList.java
- *
- * @param <E> List Type
- * @deprecated get rid of this at some point
- */
-@Deprecated/*(forRemoval = true)*/
-public class ConcurrentList<E> extends ArrayList<E> {
-
-    private final Object lock = new Object();
-
-    @Override
-    public boolean add(E e) {
-        synchronized (lock) {
-            return super.add(e);
-        }
-    }
-
-    @Override
-    public void add(int index, E element) {
-        synchronized (lock) {
-            super.add(index, element);
-        }
-    }
-
-    @Override
-    public boolean addAll(Collection<? extends E> c) {
-        synchronized (lock) {
-            return super.addAll(c);
-        }
-    }
-
-    @Override
-    public boolean addAll(int index, Collection<? extends E> c) {
-        synchronized (lock) {
-            return super.addAll(index, c);
-        }
-    }
-
-    @Override
-    public void clear() {
-        synchronized (lock) {
-            super.clear();
-        }
-    }
-
-    @Override
-    public Object clone() {
-        synchronized (lock) {
-            return super.clone();
-        }
-    }
-
-    @Override
-    public boolean contains(Object o) {
-        synchronized (lock) {
-            return super.contains(o);
-        }
-    }
-
-    @Override
-    public void ensureCapacity(int minCapacity) {
-        synchronized (lock) {
-            super.ensureCapacity(minCapacity);
-        }
-    }
-
-    @Override
-    public E get(int index) {
-        synchronized (lock) {
-            return super.get(index);
-        }
-    }
-
-    @Override
-    public int indexOf(Object o) {
-        synchronized (lock) {
-            return super.indexOf(o);
-        }
-    }
-
-    @Override
-    public int lastIndexOf(Object o) {
-        synchronized (lock) {
-            return super.lastIndexOf(o);
-        }
-    }
-
-    @Override
-    public E remove(int index) {
-        synchronized (lock) {
-            return super.remove(index);
-        }
-    }
-
-    @Override
-    public boolean remove(Object o) {
-        synchronized (lock) {
-            return super.remove(o);
-        }
-    }
-
-    @Override
-    public boolean removeAll(Collection<?> c) {
-        synchronized (lock) {
-            return super.removeAll(c);
-        }
-    }
-
-    @Override
-    public boolean retainAll(Collection<?> c) {
-        synchronized (lock) {
-            return super.retainAll(c);
-        }
-    }
-
-    @Override
-    public E set(int index, E element) {
-        synchronized (lock) {
-            return super.set(index, element);
-        }
-    }
-
-    @Override
-    public List<E> subList(int fromIndex, int toIndex) {
-        synchronized (lock) {
-            return super.subList(fromIndex, toIndex);
-        }
-    }
-
-    @Override
-    public Object[] toArray() {
-        synchronized (lock) {
-            return super.toArray();
-        }
-    }
-
-    @Override
-    public <T> T[] toArray(T[] a) {
-        synchronized (lock) {
-            return super.toArray(a);
-        }
-    }
-
-    @Override
-    public void trimToSize() {
-        synchronized (lock) {
-            super.trimToSize();
-        }
-    }
-
-    @Override
-    public ListIterator<E> listIterator() {
-        return new ListItr(0);
-    }
-
-    @Override
-    public Iterator<E> iterator() {
-        return new Itr();
-    }
-
-    private class Itr implements Iterator<E> {
-
-        protected int cursor;
-        protected int lastRet;
-        final ConcurrentList l;
-
-        public Itr() {
-            cursor = 0;
-            lastRet = -1;
-            l = (ConcurrentList) ConcurrentList.this.clone();
-        }
-
-        @Override
-        public boolean hasNext() {
-            return cursor < l.size();
-        }
-
-        @Override
-        public E next() {
-            int i = cursor;
-            if (i >= l.size()) {
-                throw new NoSuchElementException();
-            }
-            cursor = i + 1;
-            return (E) l.get(lastRet = i);
-        }
-
-        @Override
-        public void remove() {
-            if (lastRet < 0) {
-                throw new IllegalStateException();
-            }
-
-            l.remove(lastRet);
-            ConcurrentList.this.remove(lastRet);
-            cursor = lastRet;
-            lastRet = -1;
-        }
-    }
-
-    public class ListItr extends Itr implements ListIterator<E> {
-
-        ListItr(int index) {
-            super();
-            cursor = index;
-        }
-
-        @Override
-        public boolean hasPrevious() {
-            return cursor > 0;
-        }
-
-        @Override
-        public int nextIndex() {
-            return cursor;
-        }
-
-        @Override
-        public int previousIndex() {
-            return cursor - 1;
-        }
-
-        @Override
-        public E previous() {
-            int i = cursor - 1;
-            if (i < 0) {
-                throw new NoSuchElementException();
-            }
-            cursor = i;
-            return (E) l.get(lastRet = i);
-        }
-
-        @Override
-        public void set(E e) {
-            if (lastRet < 0) {
-                throw new IllegalStateException();
-            }
-
-            l.set(lastRet, e);
-            ConcurrentList.this.set(lastRet, e);
-        }
-
-        @Override
-        public void add(E e) {
-            int i = cursor;
-            l.add(i, e);
-            ConcurrentList.this.add(i, e);
-            cursor = i + 1;
-            lastRet = -1;
-        }
-    }
-}

common/src/main/java/com/viaversion/viaversion/util/SynchronizedListWrapper.java

@@ -17,28 +17,38 @@
  */
 package com.viaversion.viaversion.util;
 
+import org.checkerframework.checker.nullness.qual.NonNull;
+
 import java.util.Collection;
+import java.util.Comparator;
 import java.util.Iterator;
 import java.util.List;
 import java.util.ListIterator;
+import java.util.function.Consumer;
+import java.util.function.Predicate;
 
 /**
- * @deprecated scary
+ * Synchronized list wrapper with the addition of an add handler called when an element is added to the list.
+ *
+ * @param <E> list type
  */
-@Deprecated/*(forRemoval = true)*/
+public final class SynchronizedListWrapper<E> implements List<E> {
-public abstract class ListWrapper implements List {
+    private final List<E> list;
-    private final List list;
+    private final Consumer<E> addHandler;
 
-    public ListWrapper(List inputList) {
+    public SynchronizedListWrapper(final List<E> inputList, final Consumer<E> addHandler) {
         this.list = inputList;
+        this.addHandler = addHandler;
     }
 
-    public abstract void handleAdd(Object o);
+    public List<E> originalList() {
-
-    public List getOriginalList() {
         return list;
     }
 
+    private void handleAdd(E o) {
+        addHandler.accept(o);
+    }
+
     @Override
     public int size() {
         synchronized (this) {
@@ -53,59 +63,57 @@ public abstract class ListWrapper implements List {
         }
     }
 
-
     @Override
-    public boolean contains(Object o) {
+    public boolean contains(final Object o) {
         synchronized (this) {
             return this.list.contains(o);
         }
     }
 
     @Override
-    public Iterator iterator() {
+    public @NonNull Iterator<E> iterator() {
-        synchronized (this) {
+        // Has to be manually synched
-            return listIterator();
+        return listIterator();
-        }
     }
 
     @Override
-    public Object[] toArray() {
+    public Object @NonNull [] toArray() {
         synchronized (this) {
             return this.list.toArray();
         }
     }
 
     @Override
-    public boolean add(Object o) {
+    public boolean add(final E o) {
-        handleAdd(o);
         synchronized (this) {
+            handleAdd(o);
             return this.list.add(o);
         }
     }
 
     @Override
-    public boolean remove(Object o) {
+    public boolean remove(final Object o) {
         synchronized (this) {
             return this.list.remove(o);
         }
     }
 
     @Override
-    public boolean addAll(Collection c) {
+    public boolean addAll(final Collection<? extends E> c) {
-        for (Object o : c) {
-            handleAdd(o);
-        }
         synchronized (this) {
+            for (final E o : c) {
+                handleAdd(o);
+            }
             return this.list.addAll(c);
         }
     }
 
     @Override
-    public boolean addAll(int index, Collection c) {
+    public boolean addAll(final int index, final Collection<? extends E> c) {
-        for (Object o : c) {
-            handleAdd(o);
-        }
         synchronized (this) {
+            for (final E o : c) {
+                handleAdd(o);
+            }
             return this.list.addAll(index, c);
         }
     }
@@ -118,93 +126,135 @@ public abstract class ListWrapper implements List {
     }
 
     @Override
-    public Object get(int index) {
+    public E get(final int index) {
         synchronized (this) {
             return this.list.get(index);
         }
     }
 
     @Override
-    public Object set(int index, Object element) {
+    public E set(final int index, final E element) {
         synchronized (this) {
             return this.list.set(index, element);
         }
     }
 
     @Override
-    public void add(int index, Object element) {
+    public void add(final int index, final E element) {
         synchronized (this) {
             this.list.add(index, element);
         }
     }
 
     @Override
-    public Object remove(int index) {
+    public E remove(final int index) {
         synchronized (this) {
             return this.list.remove(index);
         }
     }
 
     @Override
-    public int indexOf(Object o) {
+    public int indexOf(final Object o) {
         synchronized (this) {
             return this.list.indexOf(o);
         }
     }
 
     @Override
-    public int lastIndexOf(Object o) {
+    public int lastIndexOf(final Object o) {
         synchronized (this) {
             return this.list.lastIndexOf(o);
         }
     }
 
     @Override
-    public ListIterator listIterator() {
+    public @NonNull ListIterator<E> listIterator() {
-        synchronized (this) {
+        // Has to be manually synched
-            return this.list.listIterator();
+        return this.list.listIterator();
-        }
     }
 
     @Override
-    public ListIterator listIterator(int index) {
+    public @NonNull ListIterator<E> listIterator(final int index) {
-        synchronized (this) {
+        // Has to be manually synched
-            return this.list.listIterator(index);
+        return this.list.listIterator(index);
-        }
     }
 
     @Override
-    public List subList(int fromIndex, int toIndex) {
+    public @NonNull List<E> subList(final int fromIndex, final int toIndex) {
+        // Not perfect
         synchronized (this) {
             return this.list.subList(fromIndex, toIndex);
         }
     }
 
     @Override
-    public boolean retainAll(Collection c) {
+    public boolean retainAll(@NonNull final Collection<?> c) {
         synchronized (this) {
             return this.list.retainAll(c);
         }
     }
 
     @Override
-    public boolean removeAll(Collection c) {
+    public boolean removeAll(@NonNull final Collection<?> c) {
         synchronized (this) {
             return this.list.removeAll(c);
         }
     }
 
     @Override
-    public boolean containsAll(Collection c) {
+    public boolean containsAll(@NonNull final Collection<?> c) {
         synchronized (this) {
             return this.list.containsAll(c);
         }
     }
 
     @Override
-    public Object[] toArray(Object[] a) {
+    public <T> T @NonNull [] toArray(final T @NonNull [] a) {
         synchronized (this) {
             return this.list.toArray(a);
         }
     }
+
+    @Override
+    public void sort(final Comparator<? super E> c) {
+        synchronized (this) {
+            list.sort(c);
+        }
+    }
+
+    @Override
+    public void forEach(Consumer<? super E> consumer) {
+        synchronized (this) {
+            list.forEach(consumer);
+        }
+    }
+
+    @Override
+    public boolean removeIf(Predicate<? super E> filter) {
+        synchronized (this) {
+            return list.removeIf(filter);
+        }
+    }
+
+    @Override
+    public boolean equals(final Object o) {
+        if (this == o) return true;
+        synchronized (this) {
+            return list.equals(o);
+        }
+    }
+
+    @Override
+    public int hashCode() {
+        synchronized (this) {
+            return list.hashCode();
+        }
+    }
+
+    @Override
+    public String toString() {
+        synchronized (this) {
+            return list.toString();
+        }
+    }
 }

sponge/src/main/java/com/viaversion/viaversion/sponge/handlers/SpongeChannelInitializer.java

@@ -20,6 +20,7 @@ package com.viaversion.viaversion.sponge.handlers;
 import com.viaversion.viaversion.api.Via;
 import com.viaversion.viaversion.api.connection.UserConnection;
 import com.viaversion.viaversion.connection.UserConnectionImpl;
+import com.viaversion.viaversion.platform.WrappedChannelInitializer;
 import com.viaversion.viaversion.protocol.ProtocolPipelineImpl;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelInitializer;
@@ -29,21 +30,23 @@ import io.netty.handler.codec.MessageToByteEncoder;
 
 import java.lang.reflect.Method;
 
-public class SpongeChannelInitializer extends ChannelInitializer<Channel> {
+public class SpongeChannelInitializer extends ChannelInitializer<Channel> implements WrappedChannelInitializer {
 
+    private static final Method INIT_CHANNEL_METHOD;
     private final ChannelInitializer<Channel> original;
-    private Method method;
 
-    public SpongeChannelInitializer(ChannelInitializer<Channel> oldInit) {
+    static {
-        this.original = oldInit;
         try {
-            this.method = ChannelInitializer.class.getDeclaredMethod("initChannel", Channel.class);
+            INIT_CHANNEL_METHOD = ChannelInitializer.class.getDeclaredMethod("initChannel", Channel.class);
-            this.method.setAccessible(true);
+            INIT_CHANNEL_METHOD.setAccessible(true);
         } catch (NoSuchMethodException e) {
-            e.printStackTrace();
+            throw new RuntimeException(e);
         }
     }
 
+    public SpongeChannelInitializer(ChannelInitializer<Channel> oldInit) {
+        this.original = oldInit;
+    }
 
     @Override
     protected void initChannel(Channel channel) throws Exception {
@@ -54,7 +57,7 @@ public class SpongeChannelInitializer extends ChannelInitializer<Channel> {
             // init protocol
             new ProtocolPipelineImpl(info);
             // Add originals
-            this.method.invoke(this.original, channel);
+            INIT_CHANNEL_METHOD.invoke(this.original, channel);
             // Add our transformers
             MessageToByteEncoder encoder = new SpongeEncodeHandler(info, (MessageToByteEncoder) channel.pipeline().get("encoder"));
             ByteToMessageDecoder decoder = new SpongeDecodeHandler(info, (ByteToMessageDecoder) channel.pipeline().get("decoder"));
@@ -62,11 +65,17 @@ public class SpongeChannelInitializer extends ChannelInitializer<Channel> {
             channel.pipeline().replace("encoder", "encoder", encoder);
             channel.pipeline().replace("decoder", "decoder", decoder);
         } else {
-            this.method.invoke(this.original, channel);
+            INIT_CHANNEL_METHOD.invoke(this.original, channel);
         }
     }
 
+    /*@Deprecated(forRemoval = true)*/
     public ChannelInitializer<Channel> getOriginal() {
         return original;
     }
+
+    @Override
+    public ChannelInitializer<Channel> original() {
+        return original;
+    }
 }

sponge/src/main/java/com/viaversion/viaversion/sponge/platform/SpongeViaInjector.java

@@ -17,260 +17,47 @@
  */
 package com.viaversion.viaversion.sponge.platform;
 
-import com.google.gson.JsonArray;
+import com.viaversion.viaversion.platform.LegacyViaInjector;
-import com.google.gson.JsonObject;
+import com.viaversion.viaversion.platform.WrappedChannelInitializer;
-import com.viaversion.viaversion.api.Via;
-import com.viaversion.viaversion.api.platform.ViaInjector;
 import com.viaversion.viaversion.sponge.handlers.SpongeChannelInitializer;
-import com.viaversion.viaversion.util.ListWrapper;
-import com.viaversion.viaversion.util.Pair;
-import com.viaversion.viaversion.util.ReflectionUtil;
 import io.netty.channel.Channel;
-import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelHandler;
 import io.netty.channel.ChannelInitializer;
+import org.checkerframework.checker.nullness.qual.Nullable;
 import org.spongepowered.api.MinecraftVersion;
 import org.spongepowered.api.Sponge;
 
-import java.lang.reflect.Field;
 import java.lang.reflect.Method;
-import java.util.ArrayList;
-import java.util.List;
 
-//TODO screams
+public class SpongeViaInjector extends LegacyViaInjector {
-public class SpongeViaInjector implements ViaInjector {
-    private List<ChannelFuture> injectedFutures = new ArrayList<>();
-    private List<Pair<Field, Object>> injectedLists = new ArrayList<>();
 
     @Override
-    public void inject() throws Exception {
+    public int getServerProtocolVersion() throws ReflectiveOperationException {
-        try {
+        MinecraftVersion version = Sponge.getPlatform().getMinecraftVersion();
-            Object connection = getServerConnection();
+        return (int) version.getClass().getDeclaredMethod("getProtocol").invoke(version);
-            if (connection == null) {
-                throw new Exception("We failed to find the core component 'ServerConnection', please file an issue on our GitHub.");
-            }
-            for (Field field : connection.getClass().getDeclaredFields()) {
-                field.setAccessible(true);
-                final Object value = field.get(connection);
-                if (value instanceof List) {
-                    // Inject the list
-                    List wrapper = new ListWrapper((List) value) {
-                        @Override
-                        public void handleAdd(Object o) {
-                            if (o instanceof ChannelFuture) {
-                                try {
-                                    injectChannelFuture((ChannelFuture) o);
-                                } catch (Exception e) {
-                                    e.printStackTrace();
-                                }
-                            }
-                        }
-                    };
-                    injectedLists.add(new Pair<>(field, connection));
-                    field.set(connection, wrapper);
-                    // Iterate through current list
-                    synchronized (wrapper) {
-                        for (Object o : (List) value) {
-                            if (o instanceof ChannelFuture) {
-                                injectChannelFuture((ChannelFuture) o);
-                            } else {
-                                break; // not the right list.
-                            }
-                        }
-                    }
-                }
-            }
-
-        } catch (Exception e) {
-            Via.getPlatform().getLogger().severe("Unable to inject ViaVersion, please post these details on our GitHub and ensure you're using a compatible server version.");
-            throw e;
-        }
-    }
-
-    private void injectChannelFuture(ChannelFuture future) throws Exception {
-        try {
-            List<String> names = future.channel().pipeline().names();
-            ChannelHandler bootstrapAcceptor = null;
-            // Pick best
-            for (String name : names) {
-                ChannelHandler handler = future.channel().pipeline().get(name);
-                try {
-                    ReflectionUtil.get(handler, "childHandler", ChannelInitializer.class);
-                    bootstrapAcceptor = handler;
-                } catch (Exception e) {
-                    // Not this one
-                }
-            }
-            // Default to first (Also allows blame to work)
-            if (bootstrapAcceptor == null) {
-                bootstrapAcceptor = future.channel().pipeline().first();
-            }
-            try {
-                ChannelInitializer<Channel> oldInit = ReflectionUtil.get(bootstrapAcceptor, "childHandler", ChannelInitializer.class);
-                ChannelInitializer newInit = new SpongeChannelInitializer(oldInit);
-
-                ReflectionUtil.set(bootstrapAcceptor, "childHandler", newInit);
-                injectedFutures.add(future);
-            } catch (NoSuchFieldException e) {
-                throw new Exception("Unable to find core component 'childHandler', please check your plugins. issue: " + bootstrapAcceptor.getClass().getName());
-
-            }
-        } catch (Exception e) {
-            Via.getPlatform().getLogger().severe("We failed to inject ViaVersion, have you got late-bind enabled with something else?");
-            throw e;
-        }
     }
 
     @Override
-    public boolean lateProtocolVersionSetting() {
+    protected @Nullable Object getServerConnection() throws ReflectiveOperationException {
-        return true;
-    }
-
-    @Override
-    public void uninject() {
-        // TODO: Uninject from players currently online
-        for (ChannelFuture future : injectedFutures) {
-            List<String> names = future.channel().pipeline().names();
-            ChannelHandler bootstrapAcceptor = null;
-            // Pick best
-            for (String name : names) {
-                ChannelHandler handler = future.channel().pipeline().get(name);
-                try {
-                    ChannelInitializer<Channel> oldInit = ReflectionUtil.get(handler, "childHandler", ChannelInitializer.class);
-                    if (oldInit instanceof SpongeChannelInitializer) {
-                        bootstrapAcceptor = handler;
-                    }
-                } catch (Exception e) {
-                    // Not this one
-                }
-            }
-            // Default to first
-            if (bootstrapAcceptor == null) {
-                bootstrapAcceptor = future.channel().pipeline().first();
-            }
-
-            try {
-                ChannelInitializer<Channel> oldInit = ReflectionUtil.get(bootstrapAcceptor, "childHandler", ChannelInitializer.class);
-                if (oldInit instanceof SpongeChannelInitializer) {
-                    ReflectionUtil.set(bootstrapAcceptor, "childHandler", ((SpongeChannelInitializer) oldInit).getOriginal());
-                }
-            } catch (Exception e) {
-                Via.getPlatform().getLogger().severe("Failed to remove injection handler, reload won't work with connections, please reboot!");
-            }
-        }
-        injectedFutures.clear();
-
-        for (Pair<Field, Object> pair : injectedLists) {
-            try {
-                Object o = pair.key().get(pair.value());
-                if (o instanceof ListWrapper) {
-                    pair.key().set(pair.value(), ((ListWrapper) o).getOriginalList());
-                }
-            } catch (IllegalAccessException e) {
-                Via.getPlatform().getLogger().severe("Failed to remove injection, reload won't work with connections, please reboot!");
-            }
-        }
-
-        injectedLists.clear();
-    }
-
-    public static Object getServer() throws Exception {
-        return Sponge.getServer();
-    }
-
-    @Override
-    public int getServerProtocolVersion() throws Exception {
-        MinecraftVersion mcv = Sponge.getPlatform().getMinecraftVersion();
-        try {
-            return (int) mcv.getClass().getDeclaredMethod("getProtocol").invoke(mcv);
-        } catch (Exception e) {
-            throw new Exception("Failed to get server protocol", e);
-        }
-    }
-
-    @Override
-    public String getEncoderName() {
-        return "encoder";
-    }
-
-    @Override
-    public String getDecoderName() {
-        return "decoder";
-    }
-
-    public static Object getServerConnection() throws Exception {
         Class<?> serverClazz = Class.forName("net.minecraft.server.MinecraftServer");
-        Object server = getServer();
+        for (Method method : serverClazz.getDeclaredMethods()) {
-        Object connection = null;
+            if (method.getReturnType().getSimpleName().equals("NetworkSystem") && method.getParameterTypes().length == 0) {
-        for (Method m : serverClazz.getDeclaredMethods()) {
+                Object connection = method.invoke(Sponge.getServer());
-            if (m.getReturnType() != null) {
+                if (connection != null) {
-                if (m.getReturnType().getSimpleName().equals("NetworkSystem")) {
+                    return connection;
-                    if (m.getParameterTypes().length == 0) {
-                        connection = m.invoke(server);
-                    }
                 }
             }
         }
-        return connection;
+        return null;
     }
 
     @Override
-    public JsonObject getDump() {
+    protected WrappedChannelInitializer createChannelInitializer(ChannelInitializer<Channel> oldInitializer) {
-        JsonObject data = new JsonObject();
+        return new SpongeChannelInitializer(oldInitializer);
-
-        // Generate information about current injections
-        JsonArray injectedChannelInitializers = new JsonArray();
-        for (ChannelFuture cf : injectedFutures) {
-            JsonObject info = new JsonObject();
-            info.addProperty("futureClass", cf.getClass().getName());
-            info.addProperty("channelClass", cf.channel().getClass().getName());
-
-            // Get information about the pipes for this channel future
-            JsonArray pipeline = new JsonArray();
-            for (String pipeName : cf.channel().pipeline().names()) {
-                JsonObject pipe = new JsonObject();
-                pipe.addProperty("name", pipeName);
-                if (cf.channel().pipeline().get(pipeName) != null) {
-                    pipe.addProperty("class", cf.channel().pipeline().get(pipeName).getClass().getName());
-                    try {
-                        Object child = ReflectionUtil.get(cf.channel().pipeline().get(pipeName), "childHandler", ChannelInitializer.class);
-                        pipe.addProperty("childClass", child.getClass().getName());
-                        if (child instanceof SpongeChannelInitializer) {
-                            pipe.addProperty("oldInit", ((SpongeChannelInitializer) child).getOriginal().getClass().getName());
-                        }
-                    } catch (Exception e) {
-                        // Don't display
-                    }
-                }
-                // Add to the pipeline array
-                pipeline.add(pipe);
-            }
-            info.add("pipeline", pipeline);
-
-            // Add to the list
-            injectedChannelInitializers.add(info);
-        }
-        data.add("injectedChannelInitializers", injectedChannelInitializers);
-
-        // Generate information about lists we've injected into
-        JsonObject wrappedLists = new JsonObject();
-        JsonObject currentLists = new JsonObject();
-        try {
-            for (Pair<Field, Object> pair : injectedLists) {
-                Object list = pair.key().get(pair.value());
-                // Note down the current value (could be overridden by another plugin)
-                currentLists.addProperty(pair.key().getName(), list.getClass().getName());
-                // Also if it's not overridden we can display what's inside our list (possibly another plugin)
-                if (list instanceof ListWrapper) {
-                    wrappedLists.addProperty(pair.key().getName(), ((ListWrapper) list).getOriginalList().getClass().getName());
-                }
-            }
-            data.add("wrappedLists", wrappedLists);
-            data.add("currentLists", currentLists);
-        } catch (Exception e) {
-            // Ignored, fields won't be present
-        }
-
-        return data;
     }
-}
+
+    @Override
+    protected void blame(ChannelHandler bootstrapAcceptor) {
+        throw new RuntimeException("Unable to find core component 'childHandler', please check your plugins. Issue: " + bootstrapAcceptor.getClass().getName());
+    }
+}

velocity/src/main/java/com/viaversion/viaversion/velocity/platform/VelocityViaInjector.java

@@ -106,16 +106,6 @@ public class VelocityViaInjector implements ViaInjector {
         return com.velocitypowered.api.network.ProtocolVersion.MINIMUM_VERSION.getProtocol();
     }
 
-    @Override
-    public String getEncoderName() {
-        return "via-encoder";
-    }
-
-    @Override
-    public String getDecoderName() {
-        return "via-decoder";
-    }
-
     @Override
     public JsonObject getDump() {
         JsonObject data = new JsonObject();