new event TabCompleteRequestEvent and deprecate TabCompleteEvent

Players with permission bungeecord.multiple_connect can have multiple connections with the same Minecraft account.
The UUID and player name is altered to avoid collision with other player:
UUID : xxxxxxxx-xxxx-VIxx-xxxx-xxxxxxxxxxxx
- The UUID version (V above) is now the provided version + 8 (for online player, it is 4, so it becomes C).
- The I digit will follow the index of the duplicated player : first duplicated player is 1, second one is 2.
- The name of the player will be the real player name, followed by the character "." (dot) followed by the duplication index.

Bedrock accounts connected using the Floodgate plugin will not be able to connect multiple times due to the risk of xUID collision.

api/src/main/java/net/md_5/bungee/api/connection/PendingConnection.java

@@ -113,4 +113,18 @@ public interface PendingConnection extends Connection
      */
     @ApiStatus.Experimental
     CompletableFuture<byte[]> retrieveCookie(String cookie);
+
+    /**
+     * Sends a login payload request to the client.
+     *
+     * @param channel the channel to send this data via
+     * @param data the data to send
+     * @return a {@link CompletableFuture} that will be completed when the Login
+     * Payload response is received. If the Vanilla client doesn't know the
+     * channel, the {@link CompletableFuture} will complete with a null value
+     * @throws IllegalStateException if the player's version is not at least
+     * 1.13
+     */
+    @ApiStatus.Experimental
+    CompletableFuture<byte[]> sendData(String channel, byte[] data);
 }

chat/pom.xml

@@ -21,7 +21,7 @@
         <dependency>
             <groupId>com.google.code.gson</groupId>
             <artifactId>gson</artifactId>
-            <version>2.10.1</version>
+            <version>2.11.0</version>
             <scope>compile</scope>
         </dependency>
     </dependencies>

chat/src/main/java/net/md_5/bungee/api/chat/BaseComponent.java

@@ -1,5 +1,6 @@
 package net.md_5.bungee.api.chat;
 
+import java.awt.Color;
 import java.util.ArrayList;
 import java.util.List;
 import lombok.AccessLevel;
@@ -129,6 +130,10 @@ public abstract class BaseComponent
             {
                 setColor( component.getColorRaw() );
             }
+            if ( replace || !style.hasShadowColor() )
+            {
+                setShadowColor( component.getShadowColorRaw() );
+            }
             if ( replace || !style.hasFont() )
             {
                 setFont( component.getFontRaw() );
@@ -175,6 +180,7 @@ public abstract class BaseComponent
         if ( retention == FormatRetention.EVENTS || retention == FormatRetention.NONE )
         {
             setColor( null );
+            setShadowColor( null );
             setBold( null );
             setItalic( null );
             setUnderlined( null );
@@ -295,6 +301,46 @@ public abstract class BaseComponent
         return style.getColor();
     }
 
+    /**
+     * Set this component's shadow color.
+     *
+     * @param color the component shadow color, or null to use the default
+     */
+    public void setShadowColor(Color color)
+    {
+        this.style.setShadowColor( color );
+    }
+
+    /**
+     * Returns the shadow color of this component. This uses the parent's shadow color if this
+     * component doesn't have one. null is returned if no shadow color is found.
+     *
+     * @return the shadow color of this component
+     */
+    public Color getShadowColor()
+    {
+        if ( !style.hasShadowColor() )
+        {
+            if ( parent == null )
+            {
+                return null;
+            }
+            return parent.getShadowColor();
+        }
+        return style.getShadowColor();
+    }
+
+    /**
+     * Returns the shadow color of this component without checking the parents
+     * shadow color. May return null
+     *
+     * @return the shadow color of this component
+     */
+    public Color getShadowColorRaw()
+    {
+        return style.getShadowColor();
+    }
+
     /**
      * Set this component's font.
      *
@@ -536,6 +582,10 @@ public abstract class BaseComponent
         {
             setColor( style.getColor() );
         }
+        if ( style.hasShadowColor() )
+        {
+            setShadowColor( style.getShadowColor() );
+        }
         if ( style.hasFont() )
         {
             setFont( style.getFont() );

chat/src/main/java/net/md_5/bungee/api/chat/ComponentStyle.java

@@ -1,5 +1,6 @@
 package net.md_5.bungee.api.chat;
 
+import java.awt.Color;
 import lombok.AllArgsConstructor;
 import lombok.EqualsAndHashCode;
 import lombok.NoArgsConstructor;
@@ -23,6 +24,10 @@ public final class ComponentStyle implements Cloneable
      * {@link ChatColor#color} should not be null).</b>
      */
     private ChatColor color;
+    /**
+     * The shadow color of this style.
+     */
+    private Color shadowColor;
     /**
      * The font of this style.
      */
@@ -68,6 +73,26 @@ public final class ComponentStyle implements Cloneable
         return ( color != null );
     }
 
+    /**
+     * Returns the shadow color of this style. May return null.
+     *
+     * @return the shadow color of this style, or null if default color
+     */
+    public Color getShadowColor()
+    {
+        return shadowColor;
+    }
+
+    /**
+     * Returns whether or not this style has a shadow color set.
+     *
+     * @return whether a shadow color is set
+     */
+    public boolean hasShadowColor()
+    {
+        return ( shadowColor != null );
+    }
+
     /**
      * Returns the font of this style. May return null.
      *
@@ -195,7 +220,7 @@ public final class ComponentStyle implements Cloneable
      */
     public boolean isEmpty()
     {
-        return color == null && font == null && bold == null
+        return color == null && shadowColor == null && font == null && bold == null
                 && italic == null && underlined == null
                 && strikethrough == null && obfuscated == null;
     }
@@ -203,7 +228,7 @@ public final class ComponentStyle implements Cloneable
     @Override
     public ComponentStyle clone()
     {
-        return new ComponentStyle( color, font, bold, italic, underlined, strikethrough, obfuscated );
+        return new ComponentStyle( color, shadowColor, font, bold, italic, underlined, strikethrough, obfuscated );
     }
 
     /**
@@ -227,6 +252,7 @@ public final class ComponentStyle implements Cloneable
     {
         return new ComponentStyleBuilder()
                 .color( other.color )
+                .shadowColor( other.shadowColor )
                 .font( other.font )
                 .bold( other.bold )
                 .italic( other.italic )

chat/src/main/java/net/md_5/bungee/api/chat/ComponentStyleBuilder.java

@@ -1,5 +1,6 @@
 package net.md_5.bungee.api.chat;
 
+import java.awt.Color;
 import net.md_5.bungee.api.ChatColor;
 
 /**
@@ -26,6 +27,7 @@ public final class ComponentStyleBuilder
 {
 
     private ChatColor color;
+    private Color shadowColor;
     private String font;
     private Boolean bold, italic, underlined, strikethrough, obfuscated;
 
@@ -41,6 +43,18 @@ public final class ComponentStyleBuilder
         return this;
     }
 
+    /**
+     * Set the style shadow color.
+     *
+     * @param shadowColor the shadow color to set, or null to use the default
+     * @return this ComponentStyleBuilder for chaining
+     */
+    public ComponentStyleBuilder shadowColor(Color shadowColor)
+    {
+        this.shadowColor = shadowColor;
+        return this;
+    }
+
     /**
      * Set the style font.
      *
@@ -121,6 +135,6 @@ public final class ComponentStyleBuilder
      */
     public ComponentStyle build()
     {
-        return new ComponentStyle( color, font, bold, italic, underlined, strikethrough, obfuscated );
+        return new ComponentStyle( color, shadowColor, font, bold, italic, underlined, strikethrough, obfuscated );
     }
 }

chat/src/main/java/net/md_5/bungee/chat/ComponentSerializer.java

@@ -20,6 +20,7 @@ import net.md_5.bungee.api.chat.ScoreComponent;
 import net.md_5.bungee.api.chat.SelectorComponent;
 import net.md_5.bungee.api.chat.TextComponent;
 import net.md_5.bungee.api.chat.TranslatableComponent;
+import net.md_5.bungee.api.chat.hover.content.Content;
 import net.md_5.bungee.api.chat.hover.content.Entity;
 import net.md_5.bungee.api.chat.hover.content.EntitySerializer;
 import net.md_5.bungee.api.chat.hover.content.Item;
@@ -158,11 +159,28 @@ public class ComponentSerializer implements JsonDeserializer<BaseComponent>
         return gson.toJsonTree( style );
     }
 
+    /**
+     * @param object the object to serialize
+     * @return the JSON string representation of the object
+     * @deprecated Error-prone, be careful which object you input here
+     */
+    @Deprecated
     public static String toString(Object object)
     {
         return gson.toJson( object );
     }
 
+    /**
+     * @param content the content to serialize
+     * @return the JSON string representation of the object
+     * @deprecated for legacy internal use only
+     */
+    @Deprecated
+    public static String toString(Content content)
+    {
+        return gson.toJson( content );
+    }
+
     public static String toString(BaseComponent component)
     {
         return gson.toJson( component );

chat/src/main/java/net/md_5/bungee/chat/ComponentStyleSerializer.java

@@ -1,5 +1,6 @@
 package net.md_5.bungee.chat;
 
+import com.google.gson.JsonArray;
 import com.google.gson.JsonDeserializationContext;
 import com.google.gson.JsonDeserializer;
 import com.google.gson.JsonElement;
@@ -8,6 +9,7 @@ import com.google.gson.JsonParseException;
 import com.google.gson.JsonPrimitive;
 import com.google.gson.JsonSerializationContext;
 import com.google.gson.JsonSerializer;
+import java.awt.Color;
 import java.lang.reflect.Type;
 import java.util.Map;
 import net.md_5.bungee.api.ChatColor;
@@ -67,6 +69,10 @@ public class ComponentStyleSerializer implements JsonSerializer<ComponentStyle>,
         {
             object.addProperty( "color", style.getColor().getName() );
         }
+        if ( style.hasShadowColor() )
+        {
+            object.addProperty( "shadow_color", style.getShadowColor().getRGB() );
+        }
         if ( style.hasFont() )
         {
             object.addProperty( "font", style.getFont() );
@@ -102,6 +108,17 @@ public class ComponentStyleSerializer implements JsonSerializer<ComponentStyle>,
                 case "color":
                     builder.color( ChatColor.of( value.getAsString() ) );
                     break;
+                case "shadow_color":
+                    if ( value.isJsonArray() )
+                    {
+                        JsonArray array = value.getAsJsonArray();
+
+                        builder.shadowColor( new Color( array.get( 0 ).getAsFloat(), array.get( 1 ).getAsFloat(), array.get( 2 ).getAsFloat(), array.get( 3 ).getAsFloat() ) );
+                    } else if ( value.isJsonPrimitive() )
+                    {
+                        builder.shadowColor( new Color( value.getAsNumber().intValue(), true ) );
+                    }
+                    break;
                 case "font":
                     builder.font( value.getAsString() );
                     break;

config/pom.xml

@@ -21,7 +21,7 @@
         <dependency>
             <groupId>com.google.code.gson</groupId>
             <artifactId>gson</artifactId>
-            <version>2.10.1</version>
+            <version>2.11.0</version>
             <scope>compile</scope>
             <optional>true</optional>
         </dependency>

native/compile-native-arm.sh

@@ -0,0 +1,29 @@
+#!/bin/sh
+
+set -eu
+
+CWD=$(pwd)
+
+echo "Compiling mbedtls"
+(cd mbedtls && CFLAGS="-fPIC -I$CWD/src/main/c -DMBEDTLS_USER_CONFIG_FILE='<mbedtls_custom_config.h>'" make CC=aarch64-linux-gnu-gcc AR=aarch64-linux-gnu-ar no_test)
+
+echo "Compiling zlib"
+(cd zlib && CFLAGS="-fPIC -DNO_GZIP" CC=aarch64-linux-gnu-gcc CHOST=arm64 ./configure --target="aarch64" --static && make CFLAGS="-fPIC -march=armv8-a+crc" CC=aarch64-linux-gnu-gcc AR=aarch64-linux-gnu-ar)
+
+CC="aarch64-linux-gnu-gcc"
+CFLAGS="-c -fPIC -O3 -Wall -Werror -I$JAVA_HOME/include/ -I$JAVA_HOME/include/linux/"
+LDFLAGS="-shared"
+
+echo "Compiling bungee"
+$CC $CFLAGS -o shared.o src/main/c/shared.c
+$CC $CFLAGS -Imbedtls/include -o NativeCipherImpl.o src/main/c/NativeCipherImpl.c
+$CC $CFLAGS -Izlib -o NativeCompressImpl.o src/main/c/NativeCompressImpl.c
+
+echo "Linking native-cipher-arm.so"
+$CC $LDFLAGS -o src/main/resources/native-cipher-arm.so shared.o NativeCipherImpl.o mbedtls/library/libmbedcrypto.a
+
+echo "Linking native-compress-arm.so"
+$CC $LDFLAGS -o src/main/resources/native-compress-arm.so shared.o NativeCompressImpl.o zlib/libz.a
+
+echo "Cleaning up"
+rm shared.o NativeCipherImpl.o NativeCompressImpl.o

native/compile-native.sh

@@ -2,11 +2,13 @@
 
 set -eu
 
+CWD=$(pwd)
+
 echo "Compiling mbedtls"
-(cd mbedtls && make no_test)
+(cd mbedtls && CFLAGS="-fPIC -I$CWD/src/main/c -DMBEDTLS_USER_CONFIG_FILE='<mbedtls_custom_config.h>'" make no_test)
 
 echo "Compiling zlib"
-(cd zlib && CFLAGS=-fPIC ./configure --static && make)
+(cd zlib && CFLAGS="-fPIC -DNO_GZIP" ./configure --static && make)
 
 CC="gcc"
 CFLAGS="-c -fPIC -O3 -Wall -Werror -I$JAVA_HOME/include/ -I$JAVA_HOME/include/linux/"

native/src/main/c/NativeCipherImpl.c

@@ -5,11 +5,15 @@
 #include "shared.h"
 #include "net_md_5_bungee_jni_cipher_NativeCipherImpl.h"
 
+// Hack to keep the compiler from optimizing the memset away
+static void *(*const volatile memset_func)(void *, int, size_t) = memset;
+
 typedef unsigned char byte;
 
 typedef struct crypto_context {
     int mode;
     mbedtls_aes_context cipher;
+    int keyLen;
     byte key[];
 } crypto_context;
 
@@ -22,6 +26,7 @@ jlong JNICALL Java_net_md_15_bungee_jni_cipher_NativeCipherImpl_init(JNIEnv* env
         return 0;
     }
 
+    crypto->keyLen = (int) keyLen;
     (*env)->GetByteArrayRegion(env, key, 0, keyLen, (jbyte*) &crypto->key);
 
     mbedtls_aes_init(&crypto->cipher);
@@ -36,6 +41,7 @@ void Java_net_md_15_bungee_jni_cipher_NativeCipherImpl_free(JNIEnv* env, jobject
     crypto_context *crypto = (crypto_context*) ctx;
 
     mbedtls_aes_free(&crypto->cipher);
+    memset_func(crypto->key, 0, (size_t) crypto->keyLen);
     free(crypto);
 }
 

native/src/main/c/NativeCompressImpl.c

@@ -3,6 +3,9 @@
 
 #include <zlib.h>
 #include "shared.h"
+#if !defined(__aarch64__)
+#include "cpuid_helper.h"
+#endif
 #include "net_md_5_bungee_jni_zlib_NativeCompressImpl.h"
 
 typedef unsigned char byte;
@@ -26,6 +29,14 @@ jint throwException(JNIEnv *env, const char* message, int err) {
     return (*env)->Throw(env, throwable);
 }
 
+JNIEXPORT jboolean JNICALL Java_net_md_15_bungee_jni_zlib_NativeCompressImpl_checkSupported(JNIEnv* env, jobject obj) {
+	#if !defined(__aarch64__)
+	return (jboolean) checkCompressionNativesSupport();
+	#else
+	return JNI_TRUE;
+	#endif
+}
+
 void JNICALL Java_net_md_15_bungee_jni_zlib_NativeCompressImpl_reset(JNIEnv* env, jobject obj, jlong ctx, jboolean compress) {
     z_stream* stream = (z_stream*) ctx;
     int ret = (compress) ? deflateReset(stream) : inflateReset(stream);

native/src/main/c/cpuid_helper.h

@@ -0,0 +1,19 @@
+// Header to check for SSE 2, SSSE 3, and SSE 4.2 support in compression natives
+// GCC only!
+
+#ifndef _INCLUDE_CPUID_HELPER_H
+#define _INCLUDE_CPUID_HELPER_H
+
+#include <stdbool.h>
+#include <cpuid.h>
+
+static inline bool checkCompressionNativesSupport() {
+    unsigned int eax, ebx, ecx, edx;
+    if(__get_cpuid(1, &eax, &ebx, &ecx, &edx)) {
+        return (edx & bit_SSE2) != 0 && (ecx & bit_SSSE3) != 0 && (ecx & bit_SSE4_2) != 0;
+    }else {
+        return false;
+    }
+}
+
+#endif // _INCLUDE_CPUID_HELPER_H

native/src/main/c/mbedtls_custom_config.h

@@ -0,0 +1,31 @@
+
+// This is a hack to deal with a glitch that happens when mbedtls is compiled against glibc
+// but then run on a linux distro that uses musl libc. This implementation of the zeroize
+// is compatible with both glibc and musl without requiring the library to be recompiled.
+
+// I checked with a disassembler and for BungeeCord's usage of the library, implementing
+// this function as a static function only resulted in 2 different subroutines referencing
+// different versions of memset_func, so we might as well keep things simple and use a
+// static function here instead of requiring the mbedtls makefile to be modified to add
+// additional source files.
+
+#ifndef _INCLUDE_MBEDTLS_CUSTOM_CONFIG_H
+#define _INCLUDE_MBEDTLS_CUSTOM_CONFIG_H
+
+#include <string.h>
+
+#define MBEDTLS_PLATFORM_ZEROIZE_ALT
+
+#define mbedtls_platform_zeroize mbedtls_platform_zeroize_impl
+
+// hack to prevent compilers from optimizing the memset away
+static void *(*const volatile memset_func)(void *, int, size_t) = memset;
+
+static void mbedtls_platform_zeroize_impl(void *buf, size_t len) {
+    if (len > 0) {
+        memset_func(buf, 0, len);
+    }
+}
+
+#endif // _INCLUDE_MBEDTLS_CUSTOM_CONFIG_H
+

native/src/main/c/net_md_5_bungee_jni_zlib_NativeCompressImpl.h

@@ -15,6 +15,14 @@ extern "C" {
 JNIEXPORT void JNICALL Java_net_md_15_bungee_jni_zlib_NativeCompressImpl_initFields
   (JNIEnv *, jclass);
 
+/*
+ * Class:     net_md_5_bungee_jni_zlib_NativeCompressImpl
+ * Method:    checkSupported
+ * Signature: ()Z
+ */
+JNIEXPORT jboolean JNICALL Java_net_md_15_bungee_jni_zlib_NativeCompressImpl_checkSupported
+  (JNIEnv *, jobject);
+
 /*
  * Class:     net_md_5_bungee_jni_zlib_NativeCompressImpl
  * Method:    end

native/src/main/java/net/md_5/bungee/jni/NativeCode.java

@@ -15,14 +15,23 @@ public final class NativeCode<T>
     private final String name;
     private final Supplier<? extends T> javaImpl;
     private final Supplier<? extends T> nativeImpl;
+    private final boolean enableNativeFlag;
+    private final boolean extendedSupportCheck;
     //
     private boolean loaded;
 
     public NativeCode(String name, Supplier<? extends T> javaImpl, Supplier<? extends T> nativeImpl)
+    {
+        this( name, javaImpl, nativeImpl, false );
+    }
+
+    public NativeCode(String name, Supplier<? extends T> javaImpl, Supplier<? extends T> nativeImpl, boolean extendedSupportCheck)
     {
         this.name = name;
         this.javaImpl = javaImpl;
         this.nativeImpl = nativeImpl;
+        this.enableNativeFlag = Boolean.parseBoolean( System.getProperty( "net.md_5.bungee.jni." + name + ".enable", "true" ) );
+        this.extendedSupportCheck = extendedSupportCheck;
     }
 
     public T newInstance()
@@ -32,8 +41,9 @@ public final class NativeCode<T>
 
     public boolean load()
     {
-        if ( !loaded && isSupported() )
+        if ( enableNativeFlag && !loaded && isSupported() )
         {
+            String name = this.name + ( isAarch64() ? "-arm" : "" );
             String fullName = "bungeecord-" + name;
 
             try
@@ -59,6 +69,13 @@ public final class NativeCode<T>
                     }
 
                     System.load( temp.getPath() );
+
+                    if ( extendedSupportCheck )
+                    {
+                        // Should throw NativeCodeException if incompatible
+                        nativeImpl.get();
+                    }
+
                     loaded = true;
                 } catch ( IOException ex )
                 {
@@ -66,6 +83,9 @@ public final class NativeCode<T>
                 } catch ( UnsatisfiedLinkError ex )
                 {
                     System.out.println( "Could not load native library: " + ex.getMessage() );
+                } catch ( NativeCodeException ex )
+                {
+                    System.out.println( "Native library " + name + " is incompatible: " + ex.getMessage() );
                 }
             }
         }
@@ -75,6 +95,16 @@ public final class NativeCode<T>
 
     public static boolean isSupported()
     {
-        return "Linux".equals( System.getProperty( "os.name" ) ) && "amd64".equals( System.getProperty( "os.arch" ) );
+        return "Linux".equals( System.getProperty( "os.name" ) ) && ( isAmd64() || isAarch64() );
+    }
+
+    private static boolean isAmd64()
+    {
+        return "amd64".equals( System.getProperty( "os.arch" ) );
+    }
+
+    private static boolean isAarch64()
+    {
+        return "aarch64".equals( System.getProperty( "os.arch" ) );
     }
 }

native/src/main/java/net/md_5/bungee/jni/NativeCodeException.java

@@ -7,4 +7,10 @@ public class NativeCodeException extends RuntimeException
     {
         super( message + " : " + reason );
     }
+
+    public NativeCodeException(String message)
+    {
+        super( message );
+    }
+
 }

native/src/main/java/net/md_5/bungee/jni/cipher/BungeeCipher.java

@@ -18,4 +18,10 @@ public interface BungeeCipher
     void cipher(ByteBuf in, ByteBuf out) throws GeneralSecurityException;
 
     ByteBuf cipher(ChannelHandlerContext ctx, ByteBuf in) throws GeneralSecurityException;
+
+    /*
+     * This indicates whether the input ByteBuf is allowed to be a CompositeByteBuf.
+     * If you need access to a memory address, you should not allow composite buffers.
+     */
+    boolean allowComposite();
 }

native/src/main/java/net/md_5/bungee/jni/cipher/JavaCipher.java

@@ -2,6 +2,7 @@ package net.md_5.bungee.jni.cipher;
 
 import io.netty.buffer.ByteBuf;
 import io.netty.channel.ChannelHandlerContext;
+import io.netty.util.concurrent.FastThreadLocal;
 import java.security.GeneralSecurityException;
 import javax.crypto.Cipher;
 import javax.crypto.SecretKey;
@@ -12,10 +13,10 @@ public class JavaCipher implements BungeeCipher
 {
 
     private final Cipher cipher;
-    private static final ThreadLocal<byte[]> heapInLocal = new EmptyByteThreadLocal();
-    private static final ThreadLocal<byte[]> heapOutLocal = new EmptyByteThreadLocal();
+    private static final FastThreadLocal<byte[]> heapInLocal = new EmptyByteThreadLocal();
+    private static final FastThreadLocal<byte[]> heapOutLocal = new EmptyByteThreadLocal();
 
-    private static class EmptyByteThreadLocal extends ThreadLocal<byte[]>
+    private static class EmptyByteThreadLocal extends FastThreadLocal<byte[]>
     {
 
         @Override
@@ -88,4 +89,10 @@ public class JavaCipher implements BungeeCipher
         in.readBytes( heapIn, 0, readableBytes );
         return heapIn;
     }
+
+    @Override
+    public boolean allowComposite()
+    {
+        return true;
+    }
 }

native/src/main/java/net/md_5/bungee/jni/cipher/NativeCipher.java

@@ -71,4 +71,10 @@ public class NativeCipher implements BungeeCipher
 
         return heapOut;
     }
+
+    @Override
+    public boolean allowComposite()
+    {
+        return false;
+    }
 }

native/src/main/java/net/md_5/bungee/jni/zlib/BungeeZlib.java

@@ -6,9 +6,17 @@ import java.util.zip.DataFormatException;
 public interface BungeeZlib
 {
 
+    public static final int OUTPUT_BUFFER_SIZE = 8192;
+
     void init(boolean compress, int level);
 
     void free();
 
     void process(ByteBuf in, ByteBuf out) throws DataFormatException;
+
+    /*
+     * This indicates whether the input ByteBuf is allowed to be a CompositeByteBuf.
+     * If you need access to a memory address, you should not allow composite buffers.
+     */
+    boolean allowComposite();
 }

native/src/main/java/net/md_5/bungee/jni/zlib/JavaZlib.java

@@ -73,4 +73,10 @@ public class JavaZlib implements BungeeZlib
             inflater.reset();
         }
     }
+
+    @Override
+    public boolean allowComposite()
+    {
+        return true;
+    }
 }

native/src/main/java/net/md_5/bungee/jni/zlib/NativeCompressImpl.java

@@ -15,6 +15,8 @@ public class NativeCompressImpl
 
     static native void initFields();
 
+    native boolean checkSupported();
+
     native void end(long ctx, boolean compress);
 
     native void reset(long ctx, boolean compress);

native/src/main/java/net/md_5/bungee/jni/zlib/NativeZlib.java

@@ -15,6 +15,14 @@ public class NativeZlib implements BungeeZlib
     private boolean compress;
     private long ctx;
 
+    public NativeZlib()
+    {
+        if ( !nativeCompress.checkSupported() )
+        {
+            throw new NativeCodeException( "This CPU does not support the required SSE 4.2 and/or PCLMUL extensions!" );
+        }
+    }
+
     @Override
     public void init(boolean compress, int level)
     {
@@ -47,7 +55,7 @@ public class NativeZlib implements BungeeZlib
 
         while ( !nativeCompress.finished && ( compress || in.isReadable() ) )
         {
-            out.ensureWritable( 8192 );
+            out.ensureWritable( OUTPUT_BUFFER_SIZE );
 
             int processed;
             try
@@ -66,4 +74,10 @@ public class NativeZlib implements BungeeZlib
         nativeCompress.consumed = 0;
         nativeCompress.finished = false;
     }
+
+    @Override
+    public boolean allowComposite()
+    {
+        return false;
+    }
 }

native/src/test/java/net/md_5/bungee/NativeZlibTest.java

@@ -15,7 +15,7 @@ import org.junit.jupiter.api.Test;
 public class NativeZlibTest
 {
 
-    private final NativeCode<BungeeZlib> factory = new NativeCode<>( "native-compress", JavaZlib::new, NativeZlib::new );
+    private final NativeCode<BungeeZlib> factory = new NativeCode<>( "native-compress", JavaZlib::new, NativeZlib::new, true );
 
     @Test
     public void doTest() throws DataFormatException

pom.xml

@@ -82,7 +82,7 @@
             <dependency>
                 <groupId>io.netty</groupId>
                 <artifactId>netty-bom</artifactId>
-                <version>4.1.110.Final</version>
+                <version>4.1.115.Final</version>
                 <type>pom</type>
                 <scope>import</scope>
             </dependency>
@@ -98,7 +98,7 @@
         <dependency>
             <groupId>com.google.guava</groupId>
             <artifactId>guava</artifactId>
-            <version>32.1.2-jre</version>
+            <version>33.3.1-jre</version>
             <scope>compile</scope>
         </dependency>
         <dependency>

protocol/src/main/java/net/md_5/bungee/protocol/DefinedPacket.java

@@ -499,7 +499,7 @@ public abstract class DefinedPacket
 
     public static BitSet readFixedBitSet(int i, ByteBuf buf)
     {
-        byte[] bits = new byte[ ( i + 8 ) >> 3 ];
+        byte[] bits = new byte[ ( i + 7 ) >> 3 ];
         buf.readBytes( bits );
 
         return BitSet.valueOf( bits );
@@ -511,7 +511,7 @@ public abstract class DefinedPacket
         {
             throw new OverflowPacketException( "BitSet too large (expected " + size + " got " + bits.size() + ")" );
         }
-        buf.writeBytes( Arrays.copyOf( bits.toByteArray(), ( size + 8 ) >> 3 ) );
+        buf.writeBytes( Arrays.copyOf( bits.toByteArray(), ( size + 7 ) >> 3 ) );
     }
 
     public void read(ByteBuf buf)

protocol/src/main/java/net/md_5/bungee/protocol/Protocol.java

@@ -98,7 +98,8 @@ public enum Protocol
                     map( ProtocolConstants.MINECRAFT_1_19_3, 0x1F ),
                     map( ProtocolConstants.MINECRAFT_1_19_4, 0x23 ),
                     map( ProtocolConstants.MINECRAFT_1_20_2, 0x24 ),
-                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x26 )
+                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x26 ),
+                    map( ProtocolConstants.MINECRAFT_1_21_2, 0x27 )
             );
             TO_CLIENT.registerPacket(
                     Login.class,
@@ -115,7 +116,8 @@ public enum Protocol
                     map( ProtocolConstants.MINECRAFT_1_19_3, 0x24 ),
                     map( ProtocolConstants.MINECRAFT_1_19_4, 0x28 ),
                     map( ProtocolConstants.MINECRAFT_1_20_2, 0x29 ),
-                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x2B )
+                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x2B ),
+                    map( ProtocolConstants.MINECRAFT_1_21_2, 0x2C )
             );
             TO_CLIENT.registerPacket( Chat.class,
                     Chat::new,
@@ -146,7 +148,8 @@ public enum Protocol
                     map( ProtocolConstants.MINECRAFT_1_19_4, 0x41 ),
                     map( ProtocolConstants.MINECRAFT_1_20_2, 0x43 ),
                     map( ProtocolConstants.MINECRAFT_1_20_3, 0x45 ),
-                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x47 )
+                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x47 ),
+                    map( ProtocolConstants.MINECRAFT_1_21_2, 0x4C )
             );
             TO_CLIENT.registerPacket(
                     BossBar.class,
@@ -206,7 +209,8 @@ public enum Protocol
                     map( ProtocolConstants.MINECRAFT_1_19_4, 0x58 ),
                     map( ProtocolConstants.MINECRAFT_1_20_2, 0x5A ),
                     map( ProtocolConstants.MINECRAFT_1_20_3, 0x5C ),
-                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x5E )
+                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x5E ),
+                    map( ProtocolConstants.MINECRAFT_1_21_2, 0x64 )
             );
             TO_CLIENT.registerPacket(
                     ScoreboardScore.class,
@@ -224,13 +228,15 @@ public enum Protocol
                     map( ProtocolConstants.MINECRAFT_1_19_4, 0x5B ),
                     map( ProtocolConstants.MINECRAFT_1_20_2, 0x5D ),
                     map( ProtocolConstants.MINECRAFT_1_20_3, 0x5F ),
-                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x61 )
+                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x61 ),
+                    map( ProtocolConstants.MINECRAFT_1_21_2, 0x68 )
             );
             TO_CLIENT.registerPacket(
                     ScoreboardScoreReset.class,
                     ScoreboardScoreReset::new,
                     map( ProtocolConstants.MINECRAFT_1_20_3, 0x42 ),
-                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x44 )
+                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x44 ),
+                    map( ProtocolConstants.MINECRAFT_1_21_2, 0x49 )
             );
             TO_CLIENT.registerPacket(
                     ScoreboardDisplay.class,
@@ -248,7 +254,8 @@ public enum Protocol
                     map( ProtocolConstants.MINECRAFT_1_19_4, 0x51 ),
                     map( ProtocolConstants.MINECRAFT_1_20_2, 0x53 ),
                     map( ProtocolConstants.MINECRAFT_1_20_3, 0x55 ),
-                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x57 )
+                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x57 ),
+                    map( ProtocolConstants.MINECRAFT_1_21_2, 0x5C )
             );
             TO_CLIENT.registerPacket(
                     Team.class,
@@ -266,7 +273,8 @@ public enum Protocol
                     map( ProtocolConstants.MINECRAFT_1_19_4, 0x5A ),
                     map( ProtocolConstants.MINECRAFT_1_20_2, 0x5C ),
                     map( ProtocolConstants.MINECRAFT_1_20_3, 0x5E ),
-                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x60 )
+                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x60 ),
+                    map( ProtocolConstants.MINECRAFT_1_21_2, 0x67 )
             );
             TO_CLIENT.registerPacket(
                     PluginMessage.class,
@@ -321,7 +329,8 @@ public enum Protocol
                     map( ProtocolConstants.MINECRAFT_1_19_4, 0x5F ),
                     map( ProtocolConstants.MINECRAFT_1_20_2, 0x61 ),
                     map( ProtocolConstants.MINECRAFT_1_20_3, 0x63 ),
-                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x65 )
+                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x65 ),
+                    map( ProtocolConstants.MINECRAFT_1_21_2, 0x6C )
             );
             TO_CLIENT.registerPacket(
                     ClearTitles.class,
@@ -342,7 +351,8 @@ public enum Protocol
                     map( ProtocolConstants.MINECRAFT_1_19_4, 0x5D ),
                     map( ProtocolConstants.MINECRAFT_1_20_2, 0x5F ),
                     map( ProtocolConstants.MINECRAFT_1_20_3, 0x61 ),
-                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x63 )
+                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x63 ),
+                    map( ProtocolConstants.MINECRAFT_1_21_2, 0x6A )
             );
             TO_CLIENT.registerPacket(
                     TitleTimes.class,
@@ -354,7 +364,8 @@ public enum Protocol
                     map( ProtocolConstants.MINECRAFT_1_19_4, 0x60 ),
                     map( ProtocolConstants.MINECRAFT_1_20_2, 0x62 ),
                     map( ProtocolConstants.MINECRAFT_1_20_3, 0x64 ),
-                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x66 )
+                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x66 ),
+                    map( ProtocolConstants.MINECRAFT_1_21_2, 0x6D )
             );
             TO_CLIENT.registerPacket(
                     SystemChat.class,
@@ -365,7 +376,8 @@ public enum Protocol
                     map( ProtocolConstants.MINECRAFT_1_19_4, 0x64 ),
                     map( ProtocolConstants.MINECRAFT_1_20_2, 0x67 ),
                     map( ProtocolConstants.MINECRAFT_1_20_3, 0x69 ),
-                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x6C )
+                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x6C ),
+                    map( ProtocolConstants.MINECRAFT_1_21_2, 0x73 )
             );
             TO_CLIENT.registerPacket(
                     PlayerListHeaderFooter.class,
@@ -387,7 +399,8 @@ public enum Protocol
                     map( ProtocolConstants.MINECRAFT_1_19_4, 0x65 ),
                     map( ProtocolConstants.MINECRAFT_1_20_2, 0x68 ),
                     map( ProtocolConstants.MINECRAFT_1_20_3, 0x6A ),
-                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x6D )
+                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x6D ),
+                    map( ProtocolConstants.MINECRAFT_1_21_2, 0x74 )
             );
             TO_CLIENT.registerPacket(
                     EntityStatus.class,
@@ -432,7 +445,8 @@ public enum Protocol
                     map( ProtocolConstants.MINECRAFT_1_19_3, 0x1C ),
                     map( ProtocolConstants.MINECRAFT_1_19_4, 0x1F ),
                     map( ProtocolConstants.MINECRAFT_1_20_2, 0x20 ),
-                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x22 )
+                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x22 ),
+                    map( ProtocolConstants.MINECRAFT_1_21_2, 0x23 )
             );
             TO_CLIENT.registerPacket(
                     ViewDistance.class,
@@ -447,7 +461,8 @@ public enum Protocol
                     map( ProtocolConstants.MINECRAFT_1_19_4, 0x4F ),
                     map( ProtocolConstants.MINECRAFT_1_20_2, 0x51 ),
                     map( ProtocolConstants.MINECRAFT_1_20_3, 0x53 ),
-                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x55 )
+                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x55 ),
+                    map( ProtocolConstants.MINECRAFT_1_21_2, 0x59 )
             );
             TO_CLIENT.registerPacket(
                     ServerData.class,
@@ -458,7 +473,8 @@ public enum Protocol
                     map( ProtocolConstants.MINECRAFT_1_19_4, 0x45 ),
                     map( ProtocolConstants.MINECRAFT_1_20_2, 0x47 ),
                     map( ProtocolConstants.MINECRAFT_1_20_3, 0x49 ),
-                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x4B )
+                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x4B ),
+                    map( ProtocolConstants.MINECRAFT_1_21_2, 0x50 )
             );
             TO_CLIENT.registerPacket(
                     PlayerListItemRemove.class,
@@ -466,7 +482,8 @@ public enum Protocol
                     map( ProtocolConstants.MINECRAFT_1_19_3, 0x35 ),
                     map( ProtocolConstants.MINECRAFT_1_19_4, 0x39 ),
                     map( ProtocolConstants.MINECRAFT_1_20_2, 0x3B ),
-                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x3D )
+                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x3D ),
+                    map( ProtocolConstants.MINECRAFT_1_21_2, 0x3F )
             );
             TO_CLIENT.registerPacket(
                     PlayerListItemUpdate.class,
@@ -474,14 +491,16 @@ public enum Protocol
                     map( ProtocolConstants.MINECRAFT_1_19_3, 0x36 ),
                     map( ProtocolConstants.MINECRAFT_1_19_4, 0x3A ),
                     map( ProtocolConstants.MINECRAFT_1_20_2, 0x3C ),
-                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x3E )
+                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x3E ),
+                    map( ProtocolConstants.MINECRAFT_1_21_2, 0x40 )
             );
             TO_CLIENT.registerPacket(
                     StartConfiguration.class,
                     StartConfiguration::new,
                     map( ProtocolConstants.MINECRAFT_1_20_2, 0x65 ),
                     map( ProtocolConstants.MINECRAFT_1_20_3, 0x67 ),
-                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x69 )
+                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x69 ),
+                    map( ProtocolConstants.MINECRAFT_1_21_2, 0x70 )
             );
             TO_CLIENT.registerPacket(
                     CookieRequest.class,
@@ -491,22 +510,26 @@ public enum Protocol
             TO_CLIENT.registerPacket(
                     StoreCookie.class,
                     StoreCookie::new,
-                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x6B )
+                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x6B ),
+                    map( ProtocolConstants.MINECRAFT_1_21_2, 0x72 )
             );
             TO_CLIENT.registerPacket(
                     Transfer.class,
                     Transfer::new,
-                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x73 )
+                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x73 ),
+                    map( ProtocolConstants.MINECRAFT_1_21_2, 0x7A )
             );
             TO_CLIENT.registerPacket(
                     DisconnectReportDetails.class,
                     DisconnectReportDetails::new,
-                    map( ProtocolConstants.MINECRAFT_1_21, 0x7A )
+                    map( ProtocolConstants.MINECRAFT_1_21, 0x7A ),
+                    map( ProtocolConstants.MINECRAFT_1_21_2, 0x81 )
             );
             TO_CLIENT.registerPacket(
                     ServerLinks.class,
                     ServerLinks::new,
-                    map( ProtocolConstants.MINECRAFT_1_21, 0x7B )
+                    map( ProtocolConstants.MINECRAFT_1_21, 0x7B ),
+                    map( ProtocolConstants.MINECRAFT_1_21_2, 0x82 )
             );
 
             TO_SERVER.registerPacket(
@@ -526,7 +549,8 @@ public enum Protocol
                     map( ProtocolConstants.MINECRAFT_1_19_4, 0x12 ),
                     map( ProtocolConstants.MINECRAFT_1_20_2, 0x14 ),
                     map( ProtocolConstants.MINECRAFT_1_20_3, 0x15 ),
-                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x18 )
+                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x18 ),
+                    map( ProtocolConstants.MINECRAFT_1_21_2, 0x1A )
             );
             TO_SERVER.registerPacket( Chat.class,
                     Chat::new,
@@ -542,19 +566,23 @@ public enum Protocol
                     ClientCommand::new,
                     map( ProtocolConstants.MINECRAFT_1_19, 0x03 ),
                     map( ProtocolConstants.MINECRAFT_1_19_1, 0x04 ),
-                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x05 )
+                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x05 ),
+                    map( ProtocolConstants.MINECRAFT_1_21_2, 0x06 )
             );
             TO_SERVER.registerPacket(
                     UnsignedClientCommand.class,
                     UnsignedClientCommand::new,
-                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x04 )
+                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x04 ),
+                    map( ProtocolConstants.MINECRAFT_1_21_2, 0x05 )
+
             );
             TO_SERVER.registerPacket(
                     ClientChat.class,
                     ClientChat::new,
                     map( ProtocolConstants.MINECRAFT_1_19, 0x04 ),
                     map( ProtocolConstants.MINECRAFT_1_19_1, 0x05 ),
-                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x06 )
+                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x06 ),
+                    map( ProtocolConstants.MINECRAFT_1_21_2, 0x07 )
             );
             TO_SERVER.registerPacket(
                     TabCompleteRequest.class,
@@ -570,7 +598,8 @@ public enum Protocol
                     map( ProtocolConstants.MINECRAFT_1_19_3, 0x08 ),
                     map( ProtocolConstants.MINECRAFT_1_19_4, 0x09 ),
                     map( ProtocolConstants.MINECRAFT_1_20_2, 0x0A ),
-                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x0B )
+                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x0B ),
+                    map( ProtocolConstants.MINECRAFT_1_21_2, 0x0D )
             );
             TO_SERVER.registerPacket(
                     ClientSettings.class,
@@ -585,7 +614,8 @@ public enum Protocol
                     map( ProtocolConstants.MINECRAFT_1_19_3, 0x07 ),
                     map( ProtocolConstants.MINECRAFT_1_19_4, 0x08 ),
                     map( ProtocolConstants.MINECRAFT_1_20_2, 0x09 ),
-                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x0A )
+                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x0A ),
+                    map( ProtocolConstants.MINECRAFT_1_21_2, 0x0C )
             );
             TO_SERVER.registerPacket(
                     PluginMessage.class,
@@ -603,18 +633,21 @@ public enum Protocol
                     map( ProtocolConstants.MINECRAFT_1_19_4, 0x0D ),
                     map( ProtocolConstants.MINECRAFT_1_20_2, 0x0F ),
                     map( ProtocolConstants.MINECRAFT_1_20_3, 0x10 ),
-                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x12 )
+                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x12 ),
+                    map( ProtocolConstants.MINECRAFT_1_21_2, 0x14 )
             );
             TO_SERVER.registerPacket(
                     StartConfiguration.class,
                     StartConfiguration::new,
                     map( ProtocolConstants.MINECRAFT_1_20_2, 0x0B ),
-                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x0C )
+                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x0C ),
+                    map( ProtocolConstants.MINECRAFT_1_21_2, 0x0E )
             );
             TO_SERVER.registerPacket(
                     CookieResponse.class,
                     CookieResponse::new,
-                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x11 )
+                    map( ProtocolConstants.MINECRAFT_1_20_5, 0x11 ),
+                    map( ProtocolConstants.MINECRAFT_1_21_2, 0x13 )
             );
         }
     },

protocol/src/main/java/net/md_5/bungee/protocol/ProtocolConstants.java

@@ -47,6 +47,8 @@ public class ProtocolConstants
     public static final int MINECRAFT_1_20_3 = 765;
     public static final int MINECRAFT_1_20_5 = 766;
     public static final int MINECRAFT_1_21 = 767;
+    public static final int MINECRAFT_1_21_2 = 768;
+    public static final int MINECRAFT_1_21_4 = 769;
     public static final List<String> SUPPORTED_VERSIONS;
     public static final List<Integer> SUPPORTED_VERSION_IDS;
 
@@ -108,13 +110,15 @@ public class ProtocolConstants
                 ProtocolConstants.MINECRAFT_1_20_2,
                 ProtocolConstants.MINECRAFT_1_20_3,
                 ProtocolConstants.MINECRAFT_1_20_5,
-                ProtocolConstants.MINECRAFT_1_21
+                ProtocolConstants.MINECRAFT_1_21,
+                ProtocolConstants.MINECRAFT_1_21_2,
+                ProtocolConstants.MINECRAFT_1_21_4
         );
 
         if ( SNAPSHOT_SUPPORT )
         {
             // supportedVersions.add( "1.21.x" );
-            // supportedVersionIds.add( ProtocolConstants.MINECRAFT_1_21 );
+            // supportedVersionIds.add( ProtocolConstants.MINECRAFT_1_21_4 );
         }
 
         SUPPORTED_VERSIONS = supportedVersions.build();

protocol/src/main/java/net/md_5/bungee/protocol/Varint21LengthFieldPrepender.java

@@ -1,27 +1,38 @@
 package net.md_5.bungee.protocol;
 
 import io.netty.buffer.ByteBuf;
-import io.netty.channel.ChannelHandler;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.handler.codec.MessageToByteEncoder;
+import io.netty.handler.codec.MessageToMessageEncoder;
+import java.util.List;
+import lombok.Setter;
 
 /**
  * Prepend length of the message as a Varint21 by writing length and data to a
  * new buffer
  */
-@ChannelHandler.Sharable
-public class Varint21LengthFieldPrepender extends MessageToByteEncoder<ByteBuf>
+public class Varint21LengthFieldPrepender extends MessageToMessageEncoder<ByteBuf>
 {
 
+    @Setter
+    private boolean compose = true;
+
     @Override
-    protected void encode(ChannelHandlerContext ctx, ByteBuf msg, ByteBuf out) throws Exception
+    protected void encode(ChannelHandlerContext ctx, ByteBuf msg, List<Object> list) throws Exception
     {
         int bodyLen = msg.readableBytes();
         int headerLen = varintSize( bodyLen );
-        out.ensureWritable( headerLen + bodyLen );
-
-        DefinedPacket.writeVarInt( bodyLen, out );
-        out.writeBytes( msg );
+        if ( compose )
+        {
+            ByteBuf buf = ctx.alloc().directBuffer( headerLen );
+            DefinedPacket.writeVarInt( bodyLen, buf );
+            list.add( ctx.alloc().compositeDirectBuffer( 2 ).addComponents( true, buf, msg.retain() ) );
+        } else
+        {
+            ByteBuf buf = ctx.alloc().directBuffer( headerLen + bodyLen );
+            DefinedPacket.writeVarInt( bodyLen, buf );
+            buf.writeBytes( msg );
+            list.add( buf );
+        }
     }
 
     static int varintSize(int paramInt)

protocol/src/main/java/net/md_5/bungee/protocol/packet/ClientCommand.java

@@ -32,7 +32,7 @@ public class ClientCommand extends DefinedPacket
     @Override
     public void read(ByteBuf buf, ProtocolConstants.Direction direction, int protocolVersion)
     {
-        command = readString( buf, 256 );
+        command = readString( buf, ( protocolVersion >= ProtocolConstants.MINECRAFT_1_20_5 ) ? 32767 : 256 );
         timestamp = buf.readLong();
         salt = buf.readLong();
 

protocol/src/main/java/net/md_5/bungee/protocol/packet/ClientSettings.java

@@ -25,6 +25,7 @@ public class ClientSettings extends DefinedPacket
     private int mainHand;
     private boolean disableTextFiltering;
     private boolean allowServerListing;
+    private ParticleStatus particleStatus;
 
     @Override
     public void read(ByteBuf buf, ProtocolConstants.Direction direction, int protocolVersion)
@@ -46,6 +47,10 @@ public class ClientSettings extends DefinedPacket
         {
             allowServerListing = buf.readBoolean();
         }
+        if ( protocolVersion >= ProtocolConstants.MINECRAFT_1_21_2 )
+        {
+            particleStatus = ParticleStatus.values()[readVarInt( buf )];
+        }
     }
 
     @Override
@@ -74,6 +79,10 @@ public class ClientSettings extends DefinedPacket
         {
             buf.writeBoolean( allowServerListing );
         }
+        if ( protocolVersion >= ProtocolConstants.MINECRAFT_1_21_2 )
+        {
+            writeVarInt( particleStatus.ordinal(), buf );
+        }
     }
 
     @Override
@@ -81,4 +90,11 @@ public class ClientSettings extends DefinedPacket
     {
         handler.handle( this );
     }
+
+    public enum ParticleStatus
+    {
+        ALL,
+        DECREASED,
+        MINIMAL;
+    }
 }

protocol/src/main/java/net/md_5/bungee/protocol/packet/CookieResponse.java

@@ -23,7 +23,7 @@ public class CookieResponse extends DefinedPacket
     public void read(ByteBuf buf, ProtocolConstants.Direction direction, int protocolVersion)
     {
         cookie = readString( buf );
-        data = readNullable( DefinedPacket::readArray, buf );
+        data = readNullable( read -> DefinedPacket.readArray( read, 5120 ), buf );
     }
 
     @Override

protocol/src/main/java/net/md_5/bungee/protocol/packet/EncryptionResponse.java

@@ -45,6 +45,10 @@ public class EncryptionResponse extends DefinedPacket
             writeArray( verifyToken, buf );
         } else
         {
+            if ( protocolVersion >= ProtocolConstants.MINECRAFT_1_19 && protocolVersion <= ProtocolConstants.MINECRAFT_1_19_3 )
+            {
+                buf.writeBoolean( false );
+            }
             buf.writeLong( encryptionData.getSalt() );
             writeArray( encryptionData.getSignature(), buf );
         }

protocol/src/main/java/net/md_5/bungee/protocol/packet/Login.java

@@ -41,6 +41,7 @@ public class Login extends DefinedPacket
     private boolean flat;
     private Location deathLocation;
     private int portalCooldown;
+    private int seaLevel;
     private boolean secureProfile;
 
     @Override
@@ -161,7 +162,10 @@ public class Login extends DefinedPacket
         {
             portalCooldown = readVarInt( buf );
         }
-
+        if ( protocolVersion >= ProtocolConstants.MINECRAFT_1_21_2 )
+        {
+            seaLevel = readVarInt( buf );
+        }
         if ( protocolVersion >= ProtocolConstants.MINECRAFT_1_20_5 )
         {
             secureProfile = buf.readBoolean();
@@ -293,7 +297,10 @@ public class Login extends DefinedPacket
         {
             writeVarInt( portalCooldown, buf );
         }
-
+        if ( protocolVersion >= ProtocolConstants.MINECRAFT_1_21_2 )
+        {
+            writeVarInt( seaLevel, buf );
+        }
         if ( protocolVersion >= ProtocolConstants.MINECRAFT_1_20_5 )
         {
             buf.writeBoolean( secureProfile );

protocol/src/main/java/net/md_5/bungee/protocol/packet/LoginSuccess.java

@@ -37,7 +37,7 @@ public class LoginSuccess extends DefinedPacket
         {
             properties = readProperties( buf );
         }
-        if ( protocolVersion >= ProtocolConstants.MINECRAFT_1_20_5 )
+        if ( protocolVersion >= ProtocolConstants.MINECRAFT_1_20_5 && protocolVersion < ProtocolConstants.MINECRAFT_1_21_2 )
         {
             // Whether the client should disconnect on its own if it receives invalid data from the server
             buf.readBoolean();
@@ -59,7 +59,7 @@ public class LoginSuccess extends DefinedPacket
         {
             writeProperties( properties, buf );
         }
-        if ( protocolVersion >= ProtocolConstants.MINECRAFT_1_20_5 )
+        if ( protocolVersion >= ProtocolConstants.MINECRAFT_1_20_5 && protocolVersion < ProtocolConstants.MINECRAFT_1_21_2 )
         {
             // Whether the client should disconnect on its own if it receives invalid data from the server
             // Vanilla sends true so we also send true

protocol/src/main/java/net/md_5/bungee/protocol/packet/PlayerListItem.java

@@ -145,5 +145,10 @@ public class PlayerListItem extends DefinedPacket
         // ADD_PLAYER & UPDATE_DISPLAY_NAME
         BaseComponent displayName;
 
+        // UPDATE_LIST_ORDER 1.21.2
+        Integer listOrder;
+
+        // UPDATE_HAT 1.21.4
+        Boolean showHat;
     }
 }

protocol/src/main/java/net/md_5/bungee/protocol/packet/PlayerListItemUpdate.java

@@ -61,6 +61,12 @@ public class PlayerListItemUpdate extends DefinedPacket
                             item.displayName = DefinedPacket.readBaseComponent( buf, protocolVersion );
                         }
                         break;
+                    case UPDATE_LIST_ORDER:
+                        item.listOrder = DefinedPacket.readVarInt( buf );
+                        break;
+                    case UPDATE_HAT:
+                        item.showHat = buf.readBoolean();
+                        break;
                 }
             }
         }
@@ -109,6 +115,12 @@ public class PlayerListItemUpdate extends DefinedPacket
                             DefinedPacket.writeBaseComponent( item.displayName, buf, protocolVersion );
                         }
                         break;
+                    case UPDATE_LIST_ORDER:
+                        DefinedPacket.writeVarInt( item.listOrder, buf );
+                        break;
+                    case UPDATE_HAT:
+                        buf.writeBoolean( item.showHat );
+                        break;
                 }
             }
         }
@@ -128,6 +140,8 @@ public class PlayerListItemUpdate extends DefinedPacket
         UPDATE_GAMEMODE,
         UPDATE_LISTED,
         UPDATE_LATENCY,
-        UPDATE_DISPLAY_NAME;
+        UPDATE_DISPLAY_NAME,
+        UPDATE_LIST_ORDER,
+        UPDATE_HAT;
     }
 }

protocol/src/main/java/net/md_5/bungee/protocol/packet/Respawn.java

@@ -30,6 +30,7 @@ public class Respawn extends DefinedPacket
     private byte copyMeta;
     private Location deathLocation;
     private int portalCooldown;
+    private int seaLevel;
 
     @Override
     public void read(ByteBuf buf, ProtocolConstants.Direction direction, int protocolVersion)
@@ -84,6 +85,10 @@ public class Respawn extends DefinedPacket
         {
             portalCooldown = readVarInt( buf );
         }
+        if ( protocolVersion >= ProtocolConstants.MINECRAFT_1_21_2 )
+        {
+            seaLevel = readVarInt( buf );
+        }
         if ( protocolVersion >= ProtocolConstants.MINECRAFT_1_20_2 )
         {
             copyMeta = buf.readByte();
@@ -148,6 +153,10 @@ public class Respawn extends DefinedPacket
         {
             writeVarInt( portalCooldown, buf );
         }
+        if ( protocolVersion >= ProtocolConstants.MINECRAFT_1_21_2 )
+        {
+            writeVarInt( seaLevel, buf );
+        }
         if ( protocolVersion >= ProtocolConstants.MINECRAFT_1_20_2 )
         {
             buf.writeByte( copyMeta );

protocol/src/main/java/net/md_5/bungee/protocol/packet/UnsignedClientCommand.java

@@ -21,7 +21,7 @@ public class UnsignedClientCommand extends DefinedPacket
     @Override
     public void read(ByteBuf buf, ProtocolConstants.Direction direction, int protocolVersion)
     {
-        command = readString( buf, 256 );
+        command = readString( buf );
     }
 
     @Override

proxy/src/main/java/net/md_5/bungee/EncryptionUtil.java

@@ -11,19 +11,18 @@ import java.security.Key;
 import java.security.KeyFactory;
 import java.security.KeyPair;
 import java.security.KeyPairGenerator;
+import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
 import java.security.PublicKey;
 import java.security.Signature;
 import java.security.spec.InvalidKeySpecException;
 import java.security.spec.X509EncodedKeySpec;
-import java.util.Arrays;
 import java.util.Base64;
 import java.util.Random;
 import java.util.UUID;
 import javax.crypto.Cipher;
 import javax.crypto.SecretKey;
 import javax.crypto.spec.SecretKeySpec;
-import lombok.Getter;
 import net.md_5.bungee.jni.NativeCode;
 import net.md_5.bungee.jni.cipher.BungeeCipher;
 import net.md_5.bungee.jni.cipher.JavaCipher;
@@ -41,8 +40,6 @@ public class EncryptionUtil
     private static final Random random = new Random();
     private static final Base64.Encoder MIME_ENCODER = Base64.getMimeEncoder( 76, "\n".getBytes( StandardCharsets.UTF_8 ) );
     public static final KeyPair keys;
-    @Getter
-    private static final SecretKey secret = new SecretKeySpec( new byte[ 16 ], "AES" );
     public static final NativeCode<BungeeCipher> nativeFactory = new NativeCode<>( "native-cipher", JavaCipher::new, NativeCipher::new );
     private static final PublicKey MOJANG_KEY;
 
@@ -111,17 +108,17 @@ public class EncryptionUtil
             return signature.verify( resp.getEncryptionData().getSignature() );
         } else
         {
-            Cipher cipher = Cipher.getInstance( "RSA" );
+            Cipher cipher = Cipher.getInstance( "RSA/ECB/PKCS1Padding" );
             cipher.init( Cipher.DECRYPT_MODE, keys.getPrivate() );
             byte[] decrypted = cipher.doFinal( resp.getVerifyToken() );
 
-            return Arrays.equals( request.getVerifyToken(), decrypted );
+            return MessageDigest.isEqual( request.getVerifyToken(), decrypted );
         }
     }
 
     public static SecretKey getSecret(EncryptionResponse resp, EncryptionRequest request) throws GeneralSecurityException
     {
-        Cipher cipher = Cipher.getInstance( "RSA" );
+        Cipher cipher = Cipher.getInstance( "RSA/ECB/PKCS1Padding" );
         cipher.init( Cipher.DECRYPT_MODE, keys.getPrivate() );
         return new SecretKeySpec( cipher.doFinal( resp.getSharedSecret() ), "AES" );
     }
@@ -146,7 +143,7 @@ public class EncryptionUtil
 
     public static byte[] encrypt(Key key, byte[] b) throws GeneralSecurityException
     {
-        Cipher hasher = Cipher.getInstance( "RSA" );
+        Cipher hasher = Cipher.getInstance( "RSA/ECB/PKCS1Padding" );
         hasher.init( Cipher.ENCRYPT_MODE, key );
         return hasher.doFinal( b );
     }

proxy/src/main/java/net/md_5/bungee/ServerConnection.java

@@ -5,7 +5,6 @@ import java.net.InetSocketAddress;
 import java.net.SocketAddress;
 import java.util.ArrayDeque;
 import java.util.Queue;
-import java.util.concurrent.ConcurrentLinkedQueue;
 import lombok.Data;
 import lombok.Getter;
 import lombok.RequiredArgsConstructor;
@@ -32,7 +31,7 @@ public class ServerConnection implements Server
     private final boolean forgeServer = false;
     @Getter
     private final Queue<KeepAliveData> keepAlives = new ArrayDeque<>();
-    private final Queue<DefinedPacket> packetQueue = new ConcurrentLinkedQueue<>();
+    private final Queue<DefinedPacket> packetQueue = new ArrayDeque<>();
 
     private final Unsafe unsafe = new Unsafe()
     {
@@ -45,23 +44,37 @@ public class ServerConnection implements Server
 
     public void sendPacketQueued(DefinedPacket packet)
     {
-        Protocol encodeProtocol = ch.getEncodeProtocol();
-        if ( !encodeProtocol.TO_SERVER.hasPacket( packet.getClass(), ch.getEncodeVersion() ) )
+        ch.scheduleIfNecessary( () ->
         {
-            packetQueue.add( packet );
-        } else
-        {
-            unsafe().sendPacket( packet );
-        }
+            if ( ch.isClosed() )
+            {
+                return;
+            }
+            Protocol encodeProtocol = ch.getEncodeProtocol();
+            if ( !encodeProtocol.TO_SERVER.hasPacket( packet.getClass(), ch.getEncodeVersion() ) )
+            {
+                packetQueue.add( packet );
+            } else
+            {
+                unsafe().sendPacket( packet );
+            }
+        } );
     }
 
     public void sendQueuedPackets()
     {
-        DefinedPacket packet;
-        while ( ( packet = packetQueue.poll() ) != null )
+        ch.scheduleIfNecessary( () ->
         {
-            unsafe().sendPacket( packet );
-        }
+            if ( ch.isClosed() )
+            {
+                return;
+            }
+            DefinedPacket packet;
+            while ( ( packet = packetQueue.poll() ) != null )
+            {
+                unsafe().sendPacket( packet );
+            }
+        } );
     }
 
     @Override
@@ -81,6 +94,7 @@ public class ServerConnection implements Server
     {
         Preconditions.checkArgument( reason.length == 0, "Server cannot have disconnect reason" );
 
+        isObsolete = true;
         ch.close();
     }
 

proxy/src/main/java/net/md_5/bungee/ServerConnector.java

@@ -137,6 +137,15 @@ public class ServerConnector extends PacketHandler
     public void disconnected(ChannelWrapper channel) throws Exception
     {
         user.getPendingConnects().remove( target );
+
+        if ( user.getServer() == null && !obsolete && user.getPendingConnects().isEmpty() && thisState == State.LOGIN_SUCCESS )
+        {
+            // this is called if we get disconnected but not have received any response after we send the handshake
+            // in this case probably an exception was thrown because the handshake could not be read correctly
+            // because of the extra ip forward data, also we skip the disconnect if another server is also in the
+            // pendingConnects queue because we don't want to lose the player
+            user.disconnect( "Unexpected disconnect during server login, did you forget to enable BungeeCord / IP forwarding on your server?" );
+        }
     }
 
     @Override
@@ -252,7 +261,7 @@ public class ServerConnector extends PacketHandler
             // Set tab list size, TODO: what shall we do about packet mutability
             Login modLogin = new Login( login.getEntityId(), login.isHardcore(), login.getGameMode(), login.getPreviousGameMode(), login.getWorldNames(), login.getDimensions(), login.getDimension(), login.getWorldName(), login.getSeed(), login.getDifficulty(),
                     (byte) user.getPendingConnection().getListener().getTabListSize(), login.getLevelType(), login.getViewDistance(), login.getSimulationDistance(), login.isReducedDebugInfo(), login.isNormalRespawn(), login.isLimitedCrafting(), login.isDebug(), login.isFlat(), login.getDeathLocation(),
-                    login.getPortalCooldown(), login.isSecureProfile() );
+                    login.getPortalCooldown(), login.getSeaLevel(), login.isSecureProfile() );
 
             user.unsafe().sendPacket( modLogin );
 
@@ -270,7 +279,7 @@ public class ServerConnector extends PacketHandler
                 user.getSentBossBars().clear();
 
                 user.unsafe().sendPacket( new Respawn( login.getDimension(), login.getWorldName(), login.getSeed(), login.getDifficulty(), login.getGameMode(), login.getPreviousGameMode(), login.getLevelType(), login.isDebug(), login.isFlat(), (byte) 0, login.getDeathLocation(),
-                        login.getPortalCooldown() ) );
+                        login.getPortalCooldown(), login.getSeaLevel() ) );
             } else
             {
                 user.unsafe().sendPacket( BungeeCord.getInstance().registerChannels( user.getPendingConnection().getVersion() ) );
@@ -332,12 +341,12 @@ public class ServerConnector extends PacketHandler
             if ( login.getDimension() == user.getDimension() )
             {
                 user.unsafe().sendPacket( new Respawn( (Integer) login.getDimension() >= 0 ? -1 : 0, login.getWorldName(), login.getSeed(), login.getDifficulty(), login.getGameMode(), login.getPreviousGameMode(), login.getLevelType(), login.isDebug(), login.isFlat(),
-                        (byte) 0, login.getDeathLocation(), login.getPortalCooldown() ) );
+                        (byte) 0, login.getDeathLocation(), login.getPortalCooldown(), login.getSeaLevel() ) );
             }
 
             user.setServerEntityId( login.getEntityId() );
             user.unsafe().sendPacket( new Respawn( login.getDimension(), login.getWorldName(), login.getSeed(), login.getDifficulty(), login.getGameMode(), login.getPreviousGameMode(), login.getLevelType(), login.isDebug(), login.isFlat(),
-                    (byte) 0, login.getDeathLocation(), login.getPortalCooldown() ) );
+                    (byte) 0, login.getDeathLocation(), login.getPortalCooldown(), login.getSeaLevel() ) );
             if ( user.getPendingConnection().getVersion() >= ProtocolConstants.MINECRAFT_1_14 )
             {
                 user.unsafe().sendPacket( new ViewDistance( login.getViewDistance() ) );
@@ -361,7 +370,10 @@ public class ServerConnector extends PacketHandler
             if ( user.getServer() != null )
             {
                 // Begin config mode
-                user.unsafe().sendPacket( new StartConfiguration() );
+                if ( user.getCh().getEncodeProtocol() != Protocol.CONFIGURATION )
+                {
+                    user.unsafe().sendPacket( new StartConfiguration() );
+                }
             } else
             {
                 LoginResult loginProfile = user.getPendingConnection().getLoginProfile();
@@ -373,7 +385,6 @@ public class ServerConnector extends PacketHandler
         // Remove from old servers
         if ( user.getServer() != null )
         {
-            user.getServer().setObsolete( true );
             user.getServer().disconnect( "Quitting" );
         }
 

proxy/src/main/java/net/md_5/bungee/UserConnection.java

@@ -11,6 +11,7 @@ import io.netty.channel.ChannelOption;
 import io.netty.util.internal.PlatformDependent;
 import java.net.InetSocketAddress;
 import java.net.SocketAddress;
+import java.util.ArrayDeque;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashSet;
@@ -21,7 +22,6 @@ import java.util.Objects;
 import java.util.Queue;
 import java.util.UUID;
 import java.util.concurrent.CompletableFuture;
-import java.util.concurrent.ConcurrentLinkedQueue;
 import java.util.logging.Level;
 import lombok.Getter;
 import lombok.NonNull;
@@ -146,7 +146,7 @@ public final class UserConnection implements ProxiedPlayer
     @Setter
     private ForgeServerHandler forgeServerHandler;
     /*========================================================================*/
-    private final Queue<DefinedPacket> packetQueue = new ConcurrentLinkedQueue<>();
+    private final Queue<DefinedPacket> packetQueue = new ArrayDeque<>();
     private final Unsafe unsafe = new Unsafe()
     {
         @Override
@@ -186,23 +186,37 @@ public final class UserConnection implements ProxiedPlayer
 
     public void sendPacketQueued(DefinedPacket packet)
     {
-        Protocol encodeProtocol = ch.getEncodeProtocol();
-        if ( !encodeProtocol.TO_CLIENT.hasPacket( packet.getClass(), getPendingConnection().getVersion() ) )
+        ch.scheduleIfNecessary( () ->
         {
-            packetQueue.add( packet );
-        } else
-        {
-            unsafe().sendPacket( packet );
-        }
+            if ( ch.isClosed() )
+            {
+                return;
+            }
+            Protocol encodeProtocol = ch.getEncodeProtocol();
+            if ( !encodeProtocol.TO_CLIENT.hasPacket( packet.getClass(), getPendingConnection().getVersion() ) )
+            {
+                packetQueue.add( packet );
+            } else
+            {
+                unsafe().sendPacket( packet );
+            }
+        } );
     }
 
     public void sendQueuedPackets()
     {
-        DefinedPacket packet;
-        while ( ( packet = packetQueue.poll() ) != null )
+        ch.scheduleIfNecessary( () ->
         {
-            unsafe().sendPacket( packet );
-        }
+            if ( ch.isClosed() )
+            {
+                return;
+            }
+            DefinedPacket packet;
+            while ( ( packet = packetQueue.poll() ) != null )
+            {
+                unsafe().sendPacket( packet );
+            }
+        } );
     }
 
     @Deprecated
@@ -306,6 +320,11 @@ public final class UserConnection implements ProxiedPlayer
     {
         Preconditions.checkNotNull( request, "request" );
 
+        ch.getHandle().eventLoop().execute( () -> connect0( request ) );
+    }
+
+    private void connect0(final ServerConnectRequest request)
+    {
         final Callback<ServerConnectRequest.Result> callback = request.getCallback();
         ServerConnectEvent event = new ServerConnectEvent( this, request.getTarget(), request.getReason(), request );
         if ( bungee.getPluginManager().callEvent( event ).isCancelled() )
@@ -315,10 +334,6 @@ public final class UserConnection implements ProxiedPlayer
                 callback.done( ServerConnectRequest.Result.EVENT_CANCEL, null );
             }
 
-            if ( getServer() == null && !ch.isClosing() )
-            {
-                throw new IllegalStateException( "Cancelled ServerConnectEvent with no server or disconnect." );
-            }
             return;
         }
 
@@ -439,7 +454,6 @@ public final class UserConnection implements ProxiedPlayer
 
             if ( server != null )
             {
-                server.setObsolete( true );
                 server.disconnect( "Quitting" );
             }
         }

proxy/src/main/java/net/md_5/bungee/compress/CompressFactory.java

@@ -8,5 +8,5 @@ import net.md_5.bungee.jni.zlib.NativeZlib;
 public class CompressFactory
 {
 
-    public static final NativeCode<BungeeZlib> zlib = new NativeCode<>( "native-compress", JavaZlib::new, NativeZlib::new );
+    public static final NativeCode<BungeeZlib> zlib = new NativeCode<>( "native-compress", JavaZlib::new, NativeZlib::new, true );
 }

proxy/src/main/java/net/md_5/bungee/compress/PacketCompressor.java

@@ -2,18 +2,23 @@ package net.md_5.bungee.compress;
 
 import io.netty.buffer.ByteBuf;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.handler.codec.MessageToByteEncoder;
+import io.netty.handler.codec.MessageToMessageEncoder;
+import java.util.List;
 import java.util.zip.Deflater;
+import lombok.Getter;
 import lombok.Setter;
 import net.md_5.bungee.jni.zlib.BungeeZlib;
 import net.md_5.bungee.protocol.DefinedPacket;
 
-public class PacketCompressor extends MessageToByteEncoder<ByteBuf>
+public class PacketCompressor extends MessageToMessageEncoder<ByteBuf>
 {
 
+    @Getter
     private final BungeeZlib zlib = CompressFactory.zlib.newInstance();
     @Setter
     private int threshold = 256;
+    @Setter
+    private boolean compose = true;
 
     @Override
     public void handlerAdded(ChannelHandlerContext ctx) throws Exception
@@ -28,18 +33,25 @@ public class PacketCompressor extends MessageToByteEncoder<ByteBuf>
     }
 
     @Override
-    protected void encode(ChannelHandlerContext ctx, ByteBuf msg, ByteBuf out) throws Exception
+    protected void encode(ChannelHandlerContext ctx, ByteBuf msg, List<Object> out) throws Exception
     {
         int origSize = msg.readableBytes();
         if ( origSize < threshold )
         {
-            DefinedPacket.writeVarInt( 0, out );
-            out.writeBytes( msg );
+            if ( compose )
+            {
+                // create a virtual buffer to avoid copying of data
+                out.add( ctx.alloc().compositeDirectBuffer( 2 ).addComponents( true, ctx.alloc().directBuffer( 1 ).writeByte( 0 ), msg.retain() ) );
+            } else
+            {
+                out.add( ctx.alloc().directBuffer( origSize + 1 ).writeByte( 0 ).writeBytes( msg ) );
+            }
         } else
         {
-            DefinedPacket.writeVarInt( origSize, out );
-
-            zlib.process( msg, out );
+            ByteBuf buf = ctx.alloc().directBuffer( BungeeZlib.OUTPUT_BUFFER_SIZE );
+            DefinedPacket.writeVarInt( origSize, buf );
+            zlib.process( msg, buf );
+            out.add( buf );
         }
     }
 }

proxy/src/main/java/net/md_5/bungee/conf/YamlConfig.java

@@ -95,7 +95,7 @@ public class YamlConfig implements ConfigurationAdapter
             } ) );
             set( "permissions.admin", Arrays.asList( new String[]
             {
-                "bungeecord.command.alert", "bungeecord.command.end", "bungeecord.command.ip", "bungeecord.command.reload", "bungeecord.command.kick"
+                "bungeecord.command.alert", "bungeecord.command.end", "bungeecord.command.ip", "bungeecord.command.reload", "bungeecord.command.kick", "bungeecord.command.send", "bungeecord.command.find"
             } ) );
         }
 

proxy/src/main/java/net/md_5/bungee/connection/InitialHandler.java

@@ -10,8 +10,10 @@ import java.nio.charset.StandardCharsets;
 import java.security.GeneralSecurityException;
 import java.security.MessageDigest;
 import java.time.Instant;
+import java.util.HashMap;
 import java.util.HashSet;
 import java.util.LinkedList;
+import java.util.Map;
 import java.util.Queue;
 import java.util.Set;
 import java.util.UUID;
@@ -66,6 +68,8 @@ import net.md_5.bungee.protocol.packet.Handshake;
 import net.md_5.bungee.protocol.packet.Kick;
 import net.md_5.bungee.protocol.packet.LegacyHandshake;
 import net.md_5.bungee.protocol.packet.LegacyPing;
+import net.md_5.bungee.protocol.packet.LoginAcknowledged;
+import net.md_5.bungee.protocol.packet.LoginPayloadRequest;
 import net.md_5.bungee.protocol.packet.LoginPayloadResponse;
 import net.md_5.bungee.protocol.packet.LoginRequest;
 import net.md_5.bungee.protocol.packet.LoginSuccess;
@@ -95,6 +99,8 @@ public class InitialHandler extends PacketHandler implements PendingConnection
     @Getter
     private final Set<String> registeredChannels = new HashSet<>();
     private State thisState = State.HANDSHAKE;
+    private int loginPayloadId;
+    private final Map<Integer, CompletableFuture<byte[]>> requestedLoginPayloads = new HashMap<>();
     private final Queue<CookieFuture> requestedCookies = new LinkedList<>();
 
     @Data
@@ -199,6 +205,7 @@ public class InitialHandler extends PacketHandler implements PendingConnection
     @Override
     public void handle(LegacyHandshake legacyHandshake) throws Exception
     {
+        Preconditions.checkState( !this.legacy, "Not expecting LegacyHandshake" );
         this.legacy = true;
         ch.close( bungee.getTranslation( "outdated_client", bungee.getGameVersion() ) );
     }
@@ -206,6 +213,7 @@ public class InitialHandler extends PacketHandler implements PendingConnection
     @Override
     public void handle(LegacyPing ping) throws Exception
     {
+        Preconditions.checkState( !this.legacy, "Not expecting LegacyPing" );
         this.legacy = true;
         final boolean v1_5 = ping.isV1_5();
 
@@ -345,7 +353,7 @@ public class InitialHandler extends PacketHandler implements PendingConnection
     @Override
     public void handle(Handshake handshake) throws Exception
     {
-        Preconditions.checkState( thisState == State.HANDSHAKE, "Not expecting HANDSHAKE" );
+        Preconditions.checkState( thisState == State.HANDSHAKE && !this.legacy, "Not expecting HANDSHAKE" );
         this.handshake = handshake;
         ch.setVersion( handshake.getProtocolVersion() );
         ch.getHandle().pipeline().remove( PipelineUtils.LEGACY_KICKER );
@@ -423,7 +431,7 @@ public class InitialHandler extends PacketHandler implements PendingConnection
     @Override
     public void handle(LoginRequest loginRequest) throws Exception
     {
-        Preconditions.checkState( thisState == State.USERNAME, "Not expecting USERNAME" );
+        Preconditions.checkState( thisState == State.USERNAME && this.loginRequest == null, "Not expecting USERNAME" );
 
         if ( !AllowedCharacters.isValidName( loginRequest.getData(), onlineMode ) )
         {
@@ -519,6 +527,8 @@ public class InitialHandler extends PacketHandler implements PendingConnection
         ch.addBefore( PipelineUtils.FRAME_DECODER, PipelineUtils.DECRYPT_HANDLER, new CipherDecoder( decrypt ) );
         BungeeCipher encrypt = EncryptionUtil.getCipher( true, sharedKey );
         ch.addBefore( PipelineUtils.FRAME_PREPENDER, PipelineUtils.ENCRYPT_HANDLER, new CipherEncoder( encrypt ) );
+        // disable use of composite buffers if we use natives
+        ch.updateComposite();
 
         String encName = URLEncoder.encode( InitialHandler.this.getName(), "UTF-8" );
 
@@ -607,34 +617,24 @@ public class InitialHandler extends PacketHandler implements PendingConnection
             }
         }
 
+        ProxiedPlayer oldName = bungee.getPlayer( getName() );
+        if ( oldName != null )
+        {
+            // TODO See #1218
+            disconnect( bungee.getTranslation( "already_connected_proxy" ) );
+            return;
+        }
+
         if ( isOnlineMode() )
         {
-            // Check for multiple connections
-            // We have to check for the old name first
-            ProxiedPlayer oldName = bungee.getPlayer( getName() );
-            if ( oldName != null )
-            {
-                // TODO See #1218
-                disconnect( bungee.getTranslation( "already_connected_proxy" ) );
-            }
             // And then also for their old UUID
             ProxiedPlayer oldID = bungee.getPlayer( getUniqueId() );
             if ( oldID != null )
-            {
-                // TODO See #1218
-                disconnect( bungee.getTranslation( "already_connected_proxy" ) );
-            }
-        } else
-        {
-            // In offline mode the existing user stays and we kick the new one
-            ProxiedPlayer oldName = bungee.getPlayer( getName() );
-            if ( oldName != null )
             {
                 // TODO See #1218
                 disconnect( bungee.getTranslation( "already_connected_proxy" ) );
                 return;
             }
-
         }
 
         Callback<LoginEvent> complete = new Callback<LoginEvent>()
@@ -724,7 +724,20 @@ public class InitialHandler extends PacketHandler implements PendingConnection
     @Override
     public void handle(LoginPayloadResponse response) throws Exception
     {
-        disconnect( "Unexpected custom LoginPayloadResponse" );
+        CompletableFuture<byte[]> future;
+        synchronized ( requestedLoginPayloads )
+        {
+            future = requestedLoginPayloads.remove( response.getId() );
+        }
+        Preconditions.checkState( future != null, "Unexpected custom LoginPayloadResponse" );
+        future.complete( response.getData() );
+    }
+
+    @Override
+    public void handle(LoginAcknowledged loginAcknowledged) throws Exception
+    {
+        // this packet should only be sent after the login success (it should be handled in the UpstreamBridge)
+        disconnect( "Unexpected LoginAcknowledged" );
     }
 
     @Override
@@ -753,6 +766,10 @@ public class InitialHandler extends PacketHandler implements PendingConnection
 
             throw CancelSendSignal.INSTANCE;
         }
+
+        // if there is no userCon we can't have a connection to a backend server that could have requested this cookie
+        // which means that this cookie is invalid as the proxy also has not requested it
+        Preconditions.checkState( userCon != null, "not requested cookie received" );
     }
 
     @Override
@@ -962,4 +979,22 @@ public class InitialHandler extends PacketHandler implements PendingConnection
 
         return future;
     }
+
+    @Override
+    public CompletableFuture<byte[]> sendData(String channel, byte[] data)
+    {
+        Preconditions.checkState( getVersion() >= ProtocolConstants.MINECRAFT_1_13, "LoginPayloads are only supported in 1.13 and above" );
+        Preconditions.checkState( ch.getEncodeProtocol() == Protocol.LOGIN, "LoginPayloads are only supported in the login phase" );
+
+        CompletableFuture<byte[]> future = new CompletableFuture<>();
+        final int id;
+        synchronized ( requestedLoginPayloads )
+        {
+            // thread safe loginPayloadId
+            id = loginPayloadId++;
+            requestedLoginPayloads.put( id, future );
+        }
+        unsafe.sendPacket( new LoginPayloadRequest( id, channel, data ) );
+        return future;
+    }
 }

proxy/src/main/java/net/md_5/bungee/connection/UpstreamBridge.java

@@ -36,6 +36,7 @@ import net.md_5.bungee.protocol.packet.CookieResponse;
 import net.md_5.bungee.protocol.packet.FinishConfiguration;
 import net.md_5.bungee.protocol.packet.KeepAlive;
 import net.md_5.bungee.protocol.packet.LoginAcknowledged;
+import net.md_5.bungee.protocol.packet.LoginPayloadResponse;
 import net.md_5.bungee.protocol.packet.PlayerListItem;
 import net.md_5.bungee.protocol.packet.PlayerListItemRemove;
 import net.md_5.bungee.protocol.packet.PluginMessage;
@@ -101,7 +102,8 @@ public class UpstreamBridge extends PacketHandler
             {
                 if ( player.getPendingConnection().getVersion() >= ProtocolConstants.MINECRAFT_1_19_3 )
                 {
-                    player.unsafe().sendPacket( newPacket );
+                    // need to queue, because players in config state could receive it
+                    ( (UserConnection) player ).sendPacketQueued( newPacket );
                 } else
                 {
                     player.unsafe().sendPacket( oldPacket );
@@ -387,6 +389,12 @@ public class UpstreamBridge extends PacketHandler
         con.getPendingConnection().handle( cookieResponse );
     }
 
+    @Override
+    public void handle(LoginPayloadResponse loginPayloadResponse) throws Exception
+    {
+        con.getPendingConnection().handle( loginPayloadResponse );
+    }
+
     @Override
     public String toString()
     {

proxy/src/main/java/net/md_5/bungee/entitymap/EntityMap.java

@@ -89,6 +89,10 @@ public abstract class EntityMap
             case ProtocolConstants.MINECRAFT_1_20_5:
             case ProtocolConstants.MINECRAFT_1_21:
                 return EntityMap_1_16_2.INSTANCE_1_20_5;
+            case ProtocolConstants.MINECRAFT_1_21_2:
+                return EntityMap_1_16_2.INSTANCE_1_21_2;
+            case ProtocolConstants.MINECRAFT_1_21_4:
+                return EntityMap_1_16_2.INSTANCE_1_21_4;
         }
         throw new RuntimeException( "Version " + version + " has no entity map" );
     }

proxy/src/main/java/net/md_5/bungee/entitymap/EntityMap_1_16_2.java

@@ -23,6 +23,8 @@ class EntityMap_1_16_2 extends EntityMap
     static final EntityMap_1_16_2 INSTANCE_1_20_2 = new EntityMap_1_16_2( -1, 0x33 );
     static final EntityMap_1_16_2 INSTANCE_1_20_3 = new EntityMap_1_16_2( -1, 0x34 );
     static final EntityMap_1_16_2 INSTANCE_1_20_5 = new EntityMap_1_16_2( -1, 0x37 );
+    static final EntityMap_1_16_2 INSTANCE_1_21_2 = new EntityMap_1_16_2( -1, 0x39 );
+    static final EntityMap_1_16_2 INSTANCE_1_21_4 = new EntityMap_1_16_2( -1, 0x3B );
     //
     private final int spawnPlayerId;
     private final int spectateId;
@@ -31,6 +33,10 @@ class EntityMap_1_16_2 extends EntityMap
     @SuppressFBWarnings("DLS_DEAD_LOCAL_STORE")
     public void rewriteClientbound(ByteBuf packet, int oldId, int newId, int protocolVersion)
     {
+        if ( spawnPlayerId == -1 )
+        {
+            return;
+        }
         // Special cases
         int readerIndex = packet.readerIndex();
         int packetId = DefinedPacket.readVarInt( packet );

proxy/src/main/java/net/md_5/bungee/netty/ChannelWrapper.java

@@ -7,15 +7,19 @@ import io.netty.channel.ChannelHandler;
 import io.netty.channel.ChannelHandlerContext;
 import java.net.SocketAddress;
 import java.util.concurrent.TimeUnit;
+import java.util.logging.Level;
 import lombok.Getter;
 import lombok.Setter;
+import net.md_5.bungee.api.ProxyServer;
 import net.md_5.bungee.compress.PacketCompressor;
 import net.md_5.bungee.compress.PacketDecompressor;
+import net.md_5.bungee.netty.cipher.CipherEncoder;
 import net.md_5.bungee.protocol.DefinedPacket;
 import net.md_5.bungee.protocol.MinecraftDecoder;
 import net.md_5.bungee.protocol.MinecraftEncoder;
 import net.md_5.bungee.protocol.PacketWrapper;
 import net.md_5.bungee.protocol.Protocol;
+import net.md_5.bungee.protocol.Varint21LengthFieldPrepender;
 import net.md_5.bungee.protocol.packet.Kick;
 
 public class ChannelWrapper
@@ -38,23 +42,22 @@ public class ChannelWrapper
 
     public Protocol getDecodeProtocol()
     {
-        return ch.pipeline().get( MinecraftDecoder.class ).getProtocol();
+        return getMinecraftDecoder().getProtocol();
     }
 
     public void setDecodeProtocol(Protocol protocol)
     {
-        ch.pipeline().get( MinecraftDecoder.class ).setProtocol( protocol );
+        getMinecraftDecoder().setProtocol( protocol );
     }
 
     public Protocol getEncodeProtocol()
     {
-        return ch.pipeline().get( MinecraftEncoder.class ).getProtocol();
-
+        return getMinecraftEncoder().getProtocol();
     }
 
     public void setEncodeProtocol(Protocol protocol)
     {
-        ch.pipeline().get( MinecraftEncoder.class ).setProtocol( protocol );
+        getMinecraftEncoder().setProtocol( protocol );
     }
 
     public void setProtocol(Protocol protocol)
@@ -65,13 +68,23 @@ public class ChannelWrapper
 
     public void setVersion(int protocol)
     {
-        ch.pipeline().get( MinecraftDecoder.class ).setProtocolVersion( protocol );
-        ch.pipeline().get( MinecraftEncoder.class ).setProtocolVersion( protocol );
+        getMinecraftDecoder().setProtocolVersion( protocol );
+        getMinecraftEncoder().setProtocolVersion( protocol );
+    }
+
+    public MinecraftDecoder getMinecraftDecoder()
+    {
+        return ch.pipeline().get( MinecraftDecoder.class );
+    }
+
+    public MinecraftEncoder getMinecraftEncoder()
+    {
+        return ch.pipeline().get( MinecraftEncoder.class );
     }
 
     public int getEncodeVersion()
     {
-        return ch.pipeline().get( MinecraftEncoder.class ).getProtocolVersion();
+        return getMinecraftEncoder().getProtocolVersion();
     }
 
     public void write(Object packet)
@@ -187,5 +200,47 @@ public class ChannelWrapper
         {
             ch.pipeline().remove( "decompress" );
         }
+        // disable use of composite buffers if we use natives
+        updateComposite();
+    }
+
+    /*
+     * Should be called on encryption add and on compressor add or remove
+     */
+    public void updateComposite()
+    {
+        CipherEncoder cipherEncoder = ch.pipeline().get( CipherEncoder.class );
+        PacketCompressor packetCompressor = ch.pipeline().get( PacketCompressor.class );
+        Varint21LengthFieldPrepender prepender = ch.pipeline().get( Varint21LengthFieldPrepender.class );
+        boolean compressorCompose = cipherEncoder == null || cipherEncoder.getCipher().allowComposite();
+        boolean prependerCompose = compressorCompose && ( packetCompressor == null || packetCompressor.getZlib().allowComposite() );
+
+        if ( prepender != null )
+        {
+            ProxyServer.getInstance().getLogger().log( Level.FINE, "set prepender compose to {0} for {1}", new Object[]
+            {
+                prependerCompose, ch
+            } );
+            prepender.setCompose( prependerCompose );
+        }
+        if ( packetCompressor != null )
+        {
+            ProxyServer.getInstance().getLogger().log( Level.FINE, "set packetCompressor compose to {0} for {1}", new Object[]
+            {
+                compressorCompose, ch
+            } );
+            packetCompressor.setCompose( compressorCompose );
+        }
+    }
+
+    public void scheduleIfNecessary(Runnable task)
+    {
+        if ( ch.eventLoop().inEventLoop() )
+        {
+            task.run();
+            return;
+        }
+
+        ch.eventLoop().execute( task );
     }
 }

proxy/src/main/java/net/md_5/bungee/netty/PipelineUtils.java

@@ -93,7 +93,6 @@ public class PipelineUtils
     public static final Base BASE = new Base( false );
     public static final Base BASE_SERVERSIDE = new Base( true );
     private static final KickStringWriter legacyKicker = new KickStringWriter();
-    private static final Varint21LengthFieldPrepender framePrepender = new Varint21LengthFieldPrepender();
     private static final Varint21LengthFieldExtraBufPrepender serverFramePrepender = new Varint21LengthFieldExtraBufPrepender();
     public static final String TIMEOUT_HANDLER = "timeout";
     public static final String PACKET_DECODER = "packet-decoder";
@@ -202,7 +201,7 @@ public class PipelineUtils
             ch.pipeline().addLast( TIMEOUT_HANDLER, new ReadTimeoutHandler( BungeeCord.getInstance().config.getTimeout(), TimeUnit.MILLISECONDS ) );
             // No encryption bungee -> server, therefore use extra buffer to avoid copying everything for length prepending
             // Not used bungee -> client as header would need to be encrypted separately through expensive JNI call
-            ch.pipeline().addLast( FRAME_PREPENDER, ( toServer ) ? serverFramePrepender : framePrepender );
+            ch.pipeline().addLast( FRAME_PREPENDER, ( toServer ) ? serverFramePrepender : new Varint21LengthFieldPrepender() );
 
             ch.pipeline().addLast( BOSS_HANDLER, new HandlerBoss() );
         }

proxy/src/main/java/net/md_5/bungee/netty/cipher/CipherEncoder.java

@@ -3,6 +3,7 @@ package net.md_5.bungee.netty.cipher;
 import io.netty.buffer.ByteBuf;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.handler.codec.MessageToByteEncoder;
+import lombok.Getter;
 import lombok.RequiredArgsConstructor;
 import net.md_5.bungee.jni.cipher.BungeeCipher;
 
@@ -10,6 +11,7 @@ import net.md_5.bungee.jni.cipher.BungeeCipher;
 public class CipherEncoder extends MessageToByteEncoder<ByteBuf>
 {
 
+    @Getter
     private final BungeeCipher cipher;
 
     @Override