#3693: Compile natives as C instead of C++, check malloc/calloc return values for null

Bumps [com.mysql:mysql-connector-j](https://github.com/mysql/mysql-connector-j) from 8.3.0 to 8.4.0.
- [Changelog](https://github.com/mysql/mysql-connector-j/blob/release/8.x/CHANGES)
- [Commits](https://github.com/mysql/mysql-connector-j/compare/8.3.0...8.4.0)

---
updated-dependencies:
- dependency-name: com.mysql:mysql-connector-j
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

api/pom.xml

@@ -6,13 +6,13 @@
     <parent>
         <groupId>net.md-5</groupId>
         <artifactId>bungeecord-parent</artifactId>
-        <version>1.20-R0.3-SNAPSHOT</version>
+        <version>1.21-R0.1-SNAPSHOT</version>
         <relativePath>../pom.xml</relativePath>
     </parent>
 
     <groupId>net.md-5</groupId>
     <artifactId>bungeecord-api</artifactId>
-    <version>1.20-R0.3-SNAPSHOT</version>
+    <version>1.21-R0.1-SNAPSHOT</version>
     <packaging>jar</packaging>
 
     <name>BungeeCord-API</name>

bootstrap/pom.xml

@@ -6,13 +6,13 @@
     <parent>
         <groupId>net.md-5</groupId>
         <artifactId>bungeecord-parent</artifactId>
-        <version>1.20-R0.3-SNAPSHOT</version>
+        <version>1.21-R0.1-SNAPSHOT</version>
         <relativePath>../pom.xml</relativePath>
     </parent>
 
     <groupId>net.md-5</groupId>
     <artifactId>bungeecord-bootstrap</artifactId>
-    <version>1.20-R0.3-SNAPSHOT</version>
+    <version>1.21-R0.1-SNAPSHOT</version>
     <packaging>jar</packaging>
 
     <name>BungeeCord-Bootstrap</name>

chat/pom.xml

@@ -6,13 +6,13 @@
     <parent>
         <groupId>net.md-5</groupId>
         <artifactId>bungeecord-parent</artifactId>
-        <version>1.20-R0.3-SNAPSHOT</version>
+        <version>1.21-R0.1-SNAPSHOT</version>
         <relativePath>../pom.xml</relativePath>
     </parent>
 
     <groupId>net.md-5</groupId>
     <artifactId>bungeecord-chat</artifactId>
-    <version>1.20-R0.3-SNAPSHOT</version>
+    <version>1.21-R0.1-SNAPSHOT</version>
     <packaging>jar</packaging>
 
     <name>BungeeCord-Chat</name>

config/pom.xml

@@ -6,13 +6,13 @@
     <parent>
         <groupId>net.md-5</groupId>
         <artifactId>bungeecord-parent</artifactId>
-        <version>1.20-R0.3-SNAPSHOT</version>
+        <version>1.21-R0.1-SNAPSHOT</version>
         <relativePath>../pom.xml</relativePath>
     </parent>
 
     <groupId>net.md-5</groupId>
     <artifactId>bungeecord-config</artifactId>
-    <version>1.20-R0.3-SNAPSHOT</version>
+    <version>1.21-R0.1-SNAPSHOT</version>
     <packaging>jar</packaging>
 
     <name>BungeeCord-Config</name>

event/pom.xml

@@ -6,13 +6,13 @@
     <parent>
         <groupId>net.md-5</groupId>
         <artifactId>bungeecord-parent</artifactId>
-        <version>1.20-R0.3-SNAPSHOT</version>
+        <version>1.21-R0.1-SNAPSHOT</version>
         <relativePath>../pom.xml</relativePath>
     </parent>
 
     <groupId>net.md-5</groupId>
     <artifactId>bungeecord-event</artifactId>
-    <version>1.20-R0.3-SNAPSHOT</version>
+    <version>1.21-R0.1-SNAPSHOT</version>
     <packaging>jar</packaging>
 
     <name>BungeeCord-Event</name>

log/pom.xml

@@ -6,13 +6,13 @@
     <parent>
         <groupId>net.md-5</groupId>
         <artifactId>bungeecord-parent</artifactId>
-        <version>1.20-R0.3-SNAPSHOT</version>
+        <version>1.21-R0.1-SNAPSHOT</version>
         <relativePath>../pom.xml</relativePath>
     </parent>
 
     <groupId>net.md-5</groupId>
     <artifactId>bungeecord-log</artifactId>
-    <version>1.20-R0.3-SNAPSHOT</version>
+    <version>1.21-R0.1-SNAPSHOT</version>
     <packaging>jar</packaging>
 
     <name>BungeeCord-Log</name>

module/cmd-alert/pom.xml

@@ -6,13 +6,13 @@
     <parent>
         <groupId>net.md-5</groupId>
         <artifactId>bungeecord-module</artifactId>
-        <version>1.20-R0.3-SNAPSHOT</version>
+        <version>1.21-R0.1-SNAPSHOT</version>
         <relativePath>../pom.xml</relativePath>
     </parent>
 
     <groupId>net.md-5</groupId>
     <artifactId>bungeecord-module-cmd-alert</artifactId>
-    <version>1.20-R0.3-SNAPSHOT</version>
+    <version>1.21-R0.1-SNAPSHOT</version>
     <packaging>jar</packaging>
 
     <name>cmd_alert</name>

module/cmd-find/pom.xml

@@ -6,13 +6,13 @@
     <parent>
         <groupId>net.md-5</groupId>
         <artifactId>bungeecord-module</artifactId>
-        <version>1.20-R0.3-SNAPSHOT</version>
+        <version>1.21-R0.1-SNAPSHOT</version>
         <relativePath>../pom.xml</relativePath>
     </parent>
 
     <groupId>net.md-5</groupId>
     <artifactId>bungeecord-module-cmd-find</artifactId>
-    <version>1.20-R0.3-SNAPSHOT</version>
+    <version>1.21-R0.1-SNAPSHOT</version>
     <packaging>jar</packaging>
 
     <name>cmd_find</name>

module/cmd-kick/pom.xml

@@ -6,13 +6,13 @@
     <parent>
         <groupId>net.md-5</groupId>
         <artifactId>bungeecord-module</artifactId>
-        <version>1.20-R0.3-SNAPSHOT</version>
+        <version>1.21-R0.1-SNAPSHOT</version>
         <relativePath>../pom.xml</relativePath>
     </parent>
 
     <groupId>net.md-5</groupId>
     <artifactId>bungeecord-module-cmd-kick</artifactId>
-    <version>1.20-R0.3-SNAPSHOT</version>
+    <version>1.21-R0.1-SNAPSHOT</version>
     <packaging>jar</packaging>
 
     <name>cmd_kick</name>

module/cmd-list/pom.xml

@@ -6,13 +6,13 @@
     <parent>
         <groupId>net.md-5</groupId>
         <artifactId>bungeecord-module</artifactId>
-        <version>1.20-R0.3-SNAPSHOT</version>
+        <version>1.21-R0.1-SNAPSHOT</version>
         <relativePath>../pom.xml</relativePath>
     </parent>
 
     <groupId>net.md-5</groupId>
     <artifactId>bungeecord-module-cmd-list</artifactId>
-    <version>1.20-R0.3-SNAPSHOT</version>
+    <version>1.21-R0.1-SNAPSHOT</version>
     <packaging>jar</packaging>
 
     <name>cmd_list</name>

module/cmd-send/pom.xml

@@ -6,13 +6,13 @@
     <parent>
         <groupId>net.md-5</groupId>
         <artifactId>bungeecord-module</artifactId>
-        <version>1.20-R0.3-SNAPSHOT</version>
+        <version>1.21-R0.1-SNAPSHOT</version>
         <relativePath>../pom.xml</relativePath>
     </parent>
 
     <groupId>net.md-5</groupId>
     <artifactId>bungeecord-module-cmd-send</artifactId>
-    <version>1.20-R0.3-SNAPSHOT</version>
+    <version>1.21-R0.1-SNAPSHOT</version>
     <packaging>jar</packaging>
 
     <name>cmd_send</name>

module/cmd-server/pom.xml

@@ -6,13 +6,13 @@
     <parent>
         <groupId>net.md-5</groupId>
         <artifactId>bungeecord-module</artifactId>
-        <version>1.20-R0.3-SNAPSHOT</version>
+        <version>1.21-R0.1-SNAPSHOT</version>
         <relativePath>../pom.xml</relativePath>
     </parent>
 
     <groupId>net.md-5</groupId>
     <artifactId>bungeecord-module-cmd-server</artifactId>
-    <version>1.20-R0.3-SNAPSHOT</version>
+    <version>1.21-R0.1-SNAPSHOT</version>
     <packaging>jar</packaging>
 
     <name>cmd_server</name>

module/pom.xml

@@ -6,13 +6,13 @@
     <parent>
         <groupId>net.md-5</groupId>
         <artifactId>bungeecord-parent</artifactId>
-        <version>1.20-R0.3-SNAPSHOT</version>
+        <version>1.21-R0.1-SNAPSHOT</version>
         <relativePath>../pom.xml</relativePath>
     </parent>
 
     <groupId>net.md-5</groupId>
     <artifactId>bungeecord-module</artifactId>
-    <version>1.20-R0.3-SNAPSHOT</version>
+    <version>1.21-R0.1-SNAPSHOT</version>
     <packaging>pom</packaging>
 
     <name>BungeeCord Modules</name>

module/reconnect-yaml/pom.xml

@@ -6,13 +6,13 @@
     <parent>
         <groupId>net.md-5</groupId>
         <artifactId>bungeecord-module</artifactId>
-        <version>1.20-R0.3-SNAPSHOT</version>
+        <version>1.21-R0.1-SNAPSHOT</version>
         <relativePath>../pom.xml</relativePath>
     </parent>
 
     <groupId>net.md-5</groupId>
     <artifactId>bungeecord-module-reconnect-yaml</artifactId>
-    <version>1.20-R0.3-SNAPSHOT</version>
+    <version>1.21-R0.1-SNAPSHOT</version>
     <packaging>jar</packaging>
 
     <name>reconnect_yaml</name>

native/compile-native.sh

@@ -8,7 +8,20 @@ echo "Compiling mbedtls"
 echo "Compiling zlib"
 (cd zlib && CFLAGS=-fPIC ./configure --static && make)
 
-CXX="g++ -shared -fPIC -O3 -Wall -Werror -I$JAVA_HOME/include/ -I$JAVA_HOME/include/linux/"
+CC="gcc"
+CFLAGS="-c -fPIC -O3 -Wall -Werror -I$JAVA_HOME/include/ -I$JAVA_HOME/include/linux/"
+LDFLAGS="-shared"
 
-$CXX -Imbedtls/include src/main/c/NativeCipherImpl.cpp -o src/main/resources/native-cipher.so mbedtls/library/libmbedcrypto.a
+echo "Compiling bungee"
-$CXX -Izlib src/main/c/NativeCompressImpl.cpp -o src/main/resources/native-compress.so zlib/libz.a
+$CC $CFLAGS -o shared.o src/main/c/shared.c 
+$CC $CFLAGS -Imbedtls/include -o NativeCipherImpl.o src/main/c/NativeCipherImpl.c
+$CC $CFLAGS -Izlib -o NativeCompressImpl.o src/main/c/NativeCompressImpl.c
+
+echo "Linking native-cipher.so"
+$CC $LDFLAGS -o src/main/resources/native-cipher.so shared.o NativeCipherImpl.o mbedtls/library/libmbedcrypto.a
+
+echo "Linking native-compress.so"
+$CC $LDFLAGS -o src/main/resources/native-compress.so shared.o NativeCompressImpl.o zlib/libz.a
+
+echo "Cleaning up"
+rm shared.o NativeCipherImpl.o NativeCompressImpl.o

native/pom.xml

@@ -6,13 +6,13 @@
     <parent>
         <groupId>net.md-5</groupId>
         <artifactId>bungeecord-parent</artifactId>
-        <version>1.20-R0.3-SNAPSHOT</version>
+        <version>1.21-R0.1-SNAPSHOT</version>
         <relativePath>../pom.xml</relativePath>
     </parent>
 
     <groupId>net.md-5</groupId>
     <artifactId>bungeecord-native</artifactId>
-    <version>1.20-R0.3-SNAPSHOT</version>
+    <version>1.21-R0.1-SNAPSHOT</version>
     <packaging>jar</packaging>
 
     <name>BungeeCord-Native</name>

native/src/main/c/NativeCipherImpl.c

@@ -2,31 +2,33 @@
 #include <string.h>
 
 #include <mbedtls/aes.h>
+#include "shared.h"
 #include "net_md_5_bungee_jni_cipher_NativeCipherImpl.h"
 
 typedef unsigned char byte;
 
-struct crypto_context {
+typedef struct crypto_context {
     int mode;
     mbedtls_aes_context cipher;
-    byte *key;
+    byte key[];
-};
+} crypto_context;
 
 jlong JNICALL Java_net_md_15_bungee_jni_cipher_NativeCipherImpl_init(JNIEnv* env, jobject obj, jboolean forEncryption, jbyteArray key) {
-    jsize keyLen = env->GetArrayLength(key);
+    jsize keyLen = (*env)->GetArrayLength(env, key);
-    jbyte *keyBytes = env->GetByteArrayElements(key, NULL);
+
+    crypto_context *crypto = (crypto_context*) malloc(sizeof (crypto_context) + (size_t) keyLen);
+    if (!crypto) {
+        throwOutOfMemoryError(env, "Failed to malloc new crypto_context");
+        return 0;
+    }
+
+    (*env)->GetByteArrayRegion(env, key, 0, keyLen, (jbyte*) &crypto->key);
 
-    crypto_context *crypto = (crypto_context*) malloc(sizeof (crypto_context));
     mbedtls_aes_init(&crypto->cipher);
-
+    mbedtls_aes_setkey_enc(&crypto->cipher, (byte*) &crypto->key, keyLen * 8);
-    mbedtls_aes_setkey_enc(&crypto->cipher, (byte*) keyBytes, keyLen * 8);
-
-    crypto->key = (byte*) malloc(keyLen);
-    memcpy(crypto->key, keyBytes, keyLen);
 
     crypto->mode = (forEncryption) ? MBEDTLS_AES_ENCRYPT : MBEDTLS_AES_DECRYPT;
 
-    env->ReleaseByteArrayElements(key, keyBytes, JNI_ABORT);
     return (jlong) crypto;
 }
 
@@ -34,7 +36,6 @@ void Java_net_md_15_bungee_jni_cipher_NativeCipherImpl_free(JNIEnv* env, jobject
     crypto_context *crypto = (crypto_context*) ctx;
 
     mbedtls_aes_free(&crypto->cipher);
-    free(crypto->key);
     free(crypto);
 }
 

native/src/main/c/NativeCompressImpl.c

@@ -2,28 +2,28 @@
 #include <string.h>
 
 #include <zlib.h>
+#include "shared.h"
 #include "net_md_5_bungee_jni_zlib_NativeCompressImpl.h"
 
 typedef unsigned char byte;
 
+static jclass classID;
 static jfieldID consumedID;
 static jfieldID finishedID;
+static jmethodID makeExceptionID;
 
 void JNICALL Java_net_md_15_bungee_jni_zlib_NativeCompressImpl_initFields(JNIEnv* env, jclass clazz) {
-    // We trust that these fields will be there
+    classID = clazz;
-    consumedID = env->GetFieldID(clazz, "consumed", "I");
+    // We trust that these will be there
-    finishedID = env->GetFieldID(clazz, "finished", "Z");
+    consumedID = (*env)->GetFieldID(env, clazz, "consumed", "I");
+    finishedID = (*env)->GetFieldID(env, clazz, "finished", "Z");
+    makeExceptionID = (*env)->GetMethodID(env, clazz, "makeException", "(Ljava/lang/String;I)Lnet/md_5/bungee/jni/NativeCodeException;");
 }
 
 jint throwException(JNIEnv *env, const char* message, int err) {
-    // These can't be static for some unknown reason
+    jstring jMessage = (*env)->NewStringUTF(env, message);
-    jclass exceptionClass = env->FindClass("net/md_5/bungee/jni/NativeCodeException");
+    jthrowable throwable = (jthrowable) (*env)->CallStaticObjectMethod(env, classID, makeExceptionID, jMessage, err);
-    jmethodID exceptionInitID = env->GetMethodID(exceptionClass, "<init>", "(Ljava/lang/String;I)V");
+    return (*env)->Throw(env, throwable);
-
-    jstring jMessage = env->NewStringUTF(message);
-
-    jthrowable throwable = (jthrowable) env->NewObject(exceptionClass, exceptionInitID, jMessage, err);
-    return env->Throw(throwable);
 }
 
 void JNICALL Java_net_md_15_bungee_jni_zlib_NativeCompressImpl_reset(JNIEnv* env, jobject obj, jlong ctx, jboolean compress) {
@@ -48,10 +48,17 @@ void JNICALL Java_net_md_15_bungee_jni_zlib_NativeCompressImpl_end(JNIEnv* env,
 
 jlong JNICALL Java_net_md_15_bungee_jni_zlib_NativeCompressImpl_init(JNIEnv* env, jobject obj, jboolean compress, jint level) {
     z_stream* stream = (z_stream*) calloc(1, sizeof (z_stream));
+    if (!stream) {
+        throwOutOfMemoryError(env, "Failed to calloc new z_stream");
+        return 0;
+    }
+
     int ret = (compress) ? deflateInit(stream, level) : inflateInit(stream);
 
     if (ret != Z_OK) {
+        free(stream);
         throwException(env, "Could not init z_stream", ret);
+        return 0;
     }
 
     return (jlong) stream;
@@ -70,15 +77,16 @@ jint JNICALL Java_net_md_15_bungee_jni_zlib_NativeCompressImpl_process(JNIEnv* e
 
     switch (ret) {
         case Z_STREAM_END:
-            env->SetBooleanField(obj, finishedID, true);
+            (*env)->SetBooleanField(env, obj, finishedID, JNI_TRUE);
             break;
         case Z_OK:
             break;
         default:
             throwException(env, "Unknown z_stream return code", ret);
+            return -1;
     }
 
-    env->SetIntField(obj, consumedID, inLength - stream->avail_in);
+    (*env)->SetIntField(env, obj, consumedID, inLength - stream->avail_in);
 
     return outLength - stream->avail_out;
 }

native/src/main/c/shared.c

@@ -0,0 +1,15 @@
+#include "shared.h"
+#include <stdlib.h>
+#include <stdio.h>
+
+void throwOutOfMemoryError(JNIEnv* env, const char* msg) {
+    jclass exceptionClass = (*env)->FindClass(env, "java/lang/OutOfMemoryError");
+    if (!exceptionClass) {
+        // If the proxy ran out of memory, loading this class may fail
+        fprintf(stderr, "OUT OF MEMORY: %s\n", msg);
+        fprintf(stderr, "Could not load class java.lang.OutOfMemoryError!\n");
+        exit(-1);
+        return;
+    }
+    (*env)->ThrowNew(env, exceptionClass, msg);
+}

native/src/main/c/shared.h

@@ -0,0 +1,10 @@
+// This header contains functions to be shared between both native libraries
+
+#include <jni.h>
+
+#ifndef _INCLUDE_SHARED_H
+#define _INCLUDE_SHARED_H
+
+void throwOutOfMemoryError(JNIEnv* env, const char* msg);
+
+#endif

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

@@ -1,6 +1,6 @@
 package net.md_5.bungee.jni;
 
-public class NativeCodeException extends Exception
+public class NativeCodeException extends RuntimeException
 {
 
     public NativeCodeException(String message, int reason)

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

@@ -1,5 +1,7 @@
 package net.md_5.bungee.jni.zlib;
 
+import net.md_5.bungee.jni.NativeCodeException;
+
 public class NativeCompressImpl
 {
 
@@ -20,4 +22,9 @@ public class NativeCompressImpl
     native long init(boolean compress, int compressionLevel);
 
     native int process(long ctx, long in, int inLength, long out, int outLength, boolean compress);
+
+    NativeCodeException makeException(String message, int err)
+    {
+        return new NativeCodeException( message, err );
+    }
 }

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

@@ -4,6 +4,7 @@ import com.google.common.base.Preconditions;
 import io.netty.buffer.ByteBuf;
 import java.util.zip.DataFormatException;
 import lombok.Getter;
+import net.md_5.bungee.jni.NativeCodeException;
 
 public class NativeZlib implements BungeeZlib
 {
@@ -48,7 +49,14 @@ public class NativeZlib implements BungeeZlib
         {
             out.ensureWritable( 8192 );
 
-            int processed = nativeCompress.process( ctx, in.memoryAddress() + in.readerIndex(), in.readableBytes(), out.memoryAddress() + out.writerIndex(), out.writableBytes(), compress );
+            int processed;
+            try
+            {
+                processed = nativeCompress.process( ctx, in.memoryAddress() + in.readerIndex(), in.readableBytes(), out.memoryAddress() + out.writerIndex(), out.writableBytes(), compress );
+            } catch ( NativeCodeException exception )
+            {
+                throw (DataFormatException) new DataFormatException( "Failed to decompress via Zlib!" ).initCause( exception );
+            }
 
             in.readerIndex( in.readerIndex() + nativeCompress.consumed );
             out.writerIndex( out.writerIndex() + processed );

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

@@ -28,6 +28,17 @@ public class NativeZlibTest
         test( new JavaZlib() );
     }
 
+    @Test
+    public void testException() throws DataFormatException
+    {
+        if ( NativeCode.isSupported() )
+        {
+            assertTrue( factory.load(), "Native code failed to load!" );
+            testExceptionImpl( factory.newInstance() );
+        }
+        testExceptionImpl( new JavaZlib() );
+    }
+
     private void test(BungeeZlib zlib) throws DataFormatException
     {
         System.out.println( "Testing: " + zlib );
@@ -66,4 +77,22 @@ public class NativeZlibTest
 
         assertTrue( Arrays.equals( dataBuf, check ), "Results do not match" );
     }
+
+    private void testExceptionImpl(BungeeZlib zlib) throws DataFormatException
+    {
+        System.out.println( "Testing Exception: " + zlib );
+        long start = System.currentTimeMillis();
+
+        byte[] dataBuf = new byte[ 1 << 12 ]; // 4096 random bytes
+        new Random().nextBytes( dataBuf );
+
+        zlib.init( false, 0 );
+
+        ByteBuf originalBuf = Unpooled.directBuffer();
+        originalBuf.writeBytes( dataBuf );
+
+        ByteBuf decompressed = Unpooled.directBuffer();
+
+        assertThrows( DataFormatException.class, () -> zlib.process( originalBuf, decompressed ), "Decompressing random bytes did not result in a DataFormatException!" );
+    }
 }

pom.xml

@@ -5,7 +5,7 @@
 
     <groupId>net.md-5</groupId>
     <artifactId>bungeecord-parent</artifactId>
-    <version>1.20-R0.3-SNAPSHOT</version>
+    <version>1.21-R0.1-SNAPSHOT</version>
     <packaging>pom</packaging>
 
     <name>BungeeCord-Parent</name>
@@ -83,7 +83,7 @@
             <dependency>
                 <groupId>io.netty</groupId>
                 <artifactId>netty-bom</artifactId>
-                <version>4.1.109.Final</version>
+                <version>4.1.110.Final</version>
                 <type>pom</type>
                 <scope>import</scope>
             </dependency>

protocol/pom.xml

@@ -6,13 +6,13 @@
     <parent>
         <groupId>net.md-5</groupId>
         <artifactId>bungeecord-parent</artifactId>
-        <version>1.20-R0.3-SNAPSHOT</version>
+        <version>1.21-R0.1-SNAPSHOT</version>
         <relativePath>../pom.xml</relativePath>
     </parent>
 
     <groupId>net.md-5</groupId>
     <artifactId>bungeecord-protocol</artifactId>
-    <version>1.20-R0.3-SNAPSHOT</version>
+    <version>1.21-R0.1-SNAPSHOT</version>
     <packaging>jar</packaging>
 
     <name>BungeeCord-Protocol</name>

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

@@ -10,6 +10,7 @@ import net.md_5.bungee.protocol.packet.ClientStatus;
 import net.md_5.bungee.protocol.packet.Commands;
 import net.md_5.bungee.protocol.packet.CookieRequest;
 import net.md_5.bungee.protocol.packet.CookieResponse;
+import net.md_5.bungee.protocol.packet.DisconnectReportDetails;
 import net.md_5.bungee.protocol.packet.EncryptionRequest;
 import net.md_5.bungee.protocol.packet.EncryptionResponse;
 import net.md_5.bungee.protocol.packet.EntityStatus;
@@ -38,6 +39,7 @@ import net.md_5.bungee.protocol.packet.ScoreboardObjective;
 import net.md_5.bungee.protocol.packet.ScoreboardScore;
 import net.md_5.bungee.protocol.packet.ScoreboardScoreReset;
 import net.md_5.bungee.protocol.packet.ServerData;
+import net.md_5.bungee.protocol.packet.ServerLinks;
 import net.md_5.bungee.protocol.packet.SetCompression;
 import net.md_5.bungee.protocol.packet.StartConfiguration;
 import net.md_5.bungee.protocol.packet.StatusRequest;
@@ -268,4 +270,12 @@ public abstract class AbstractPacketHandler
     public void handle(CookieResponse cookieResponse) throws Exception
     {
     }
+
+    public void handle(DisconnectReportDetails disconnectReportDetails) throws Exception
+    {
+    }
+
+    public void handle(ServerLinks serverLinks) throws Exception
+    {
+    }
 }

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

@@ -18,6 +18,7 @@ import net.md_5.bungee.protocol.packet.ClientSettings;
 import net.md_5.bungee.protocol.packet.Commands;
 import net.md_5.bungee.protocol.packet.CookieRequest;
 import net.md_5.bungee.protocol.packet.CookieResponse;
+import net.md_5.bungee.protocol.packet.DisconnectReportDetails;
 import net.md_5.bungee.protocol.packet.EncryptionRequest;
 import net.md_5.bungee.protocol.packet.EncryptionResponse;
 import net.md_5.bungee.protocol.packet.EntityStatus;
@@ -44,6 +45,7 @@ import net.md_5.bungee.protocol.packet.ScoreboardObjective;
 import net.md_5.bungee.protocol.packet.ScoreboardScore;
 import net.md_5.bungee.protocol.packet.ScoreboardScoreReset;
 import net.md_5.bungee.protocol.packet.ServerData;
+import net.md_5.bungee.protocol.packet.ServerLinks;
 import net.md_5.bungee.protocol.packet.SetCompression;
 import net.md_5.bungee.protocol.packet.StartConfiguration;
 import net.md_5.bungee.protocol.packet.StatusRequest;
@@ -496,6 +498,16 @@ public enum Protocol
                     Transfer::new,
                     map( ProtocolConstants.MINECRAFT_1_20_5, 0x73 )
             );
+            TO_CLIENT.registerPacket(
+                    DisconnectReportDetails.class,
+                    DisconnectReportDetails::new,
+                    map( ProtocolConstants.MINECRAFT_1_21, 0x7A )
+            );
+            TO_CLIENT.registerPacket(
+                    ServerLinks.class,
+                    ServerLinks::new,
+                    map( ProtocolConstants.MINECRAFT_1_21, 0x7B )
+            );
 
             TO_SERVER.registerPacket(
                     KeepAlive.class,
@@ -742,6 +754,16 @@ public enum Protocol
                     Transfer::new,
                     map( ProtocolConstants.MINECRAFT_1_20_5, 0x0B )
             );
+            TO_CLIENT.registerPacket(
+                    DisconnectReportDetails.class,
+                    DisconnectReportDetails::new,
+                    map( ProtocolConstants.MINECRAFT_1_21, 0x0F )
+            );
+            TO_CLIENT.registerPacket(
+                    ServerLinks.class,
+                    ServerLinks::new,
+                    map( ProtocolConstants.MINECRAFT_1_21, 0x10 )
+            );
 
             TO_SERVER.registerPacket(
                     ClientSettings.class,

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

@@ -46,6 +46,7 @@ public class ProtocolConstants
     public static final int MINECRAFT_1_20_2 = 764;
     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 List<String> SUPPORTED_VERSIONS;
     public static final List<Integer> SUPPORTED_VERSION_IDS;
 
@@ -64,7 +65,8 @@ public class ProtocolConstants
                 "1.17.x",
                 "1.18.x",
                 "1.19.x",
-                "1.20.x"
+                "1.20.x",
+                "1.21.x"
         );
         ImmutableList.Builder<Integer> supportedVersionIds = ImmutableList.<Integer>builder().add(
                 ProtocolConstants.MINECRAFT_1_8,
@@ -105,13 +107,14 @@ public class ProtocolConstants
                 ProtocolConstants.MINECRAFT_1_20,
                 ProtocolConstants.MINECRAFT_1_20_2,
                 ProtocolConstants.MINECRAFT_1_20_3,
-                ProtocolConstants.MINECRAFT_1_20_5
+                ProtocolConstants.MINECRAFT_1_20_5,
+                ProtocolConstants.MINECRAFT_1_21
         );
 
         if ( SNAPSHOT_SUPPORT )
         {
-            // supportedVersions.add( "1.20.x" );
+            // supportedVersions.add( "1.21.x" );
-            // supportedVersionIds.add( ProtocolConstants.MINECRAFT_1_20_5 );
+            // supportedVersionIds.add( ProtocolConstants.MINECRAFT_1_21 );
         }
 
         SUPPORTED_VERSIONS = supportedVersions.build();

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

@@ -0,0 +1,55 @@
+package net.md_5.bungee.protocol.packet;
+
+import com.google.common.base.Preconditions;
+import io.netty.buffer.ByteBuf;
+import java.util.HashMap;
+import java.util.Map;
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+import lombok.NoArgsConstructor;
+import net.md_5.bungee.protocol.AbstractPacketHandler;
+import net.md_5.bungee.protocol.DefinedPacket;
+import net.md_5.bungee.protocol.ProtocolConstants;
+
+@Data
+@NoArgsConstructor
+@AllArgsConstructor
+@EqualsAndHashCode(callSuper = false)
+public class DisconnectReportDetails extends DefinedPacket
+{
+
+    private Map<String, String> details;
+
+    @Override
+    public void read(ByteBuf buf, ProtocolConstants.Direction direction, int protocolVersion)
+    {
+        int len = readVarInt( buf );
+        Preconditions.checkArgument( len <= 32, "Too many details" );
+
+        details = new HashMap<>();
+        for ( int i = 0; i < len; i++ )
+        {
+            details.put( readString( buf, 128 ), readString( buf, 4096 ) );
+        }
+    }
+
+    @Override
+    public void write(ByteBuf buf, ProtocolConstants.Direction direction, int protocolVersion)
+    {
+        Preconditions.checkArgument( details.size() <= 32, "Too many details" );
+        writeVarInt( details.size(), buf );
+
+        for ( Map.Entry<String, String> detail : details.entrySet() )
+        {
+            writeString( detail.getKey(), buf, 128 );
+            writeString( detail.getValue(), buf, 4096 );
+        }
+    }
+
+    @Override
+    public void handle(AbstractPacketHandler handler) throws Exception
+    {
+        handler.handle( this );
+    }
+}

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

@@ -0,0 +1,92 @@
+package net.md_5.bungee.protocol.packet;
+
+import io.netty.buffer.ByteBuf;
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+import lombok.NoArgsConstructor;
+import net.md_5.bungee.api.chat.BaseComponent;
+import net.md_5.bungee.protocol.AbstractPacketHandler;
+import net.md_5.bungee.protocol.DefinedPacket;
+import net.md_5.bungee.protocol.Either;
+import net.md_5.bungee.protocol.ProtocolConstants;
+
+@Data
+@NoArgsConstructor
+@AllArgsConstructor
+@EqualsAndHashCode(callSuper = false)
+public class ServerLinks extends DefinedPacket
+{
+
+    private Link[] links;
+
+    @Override
+    public void read(ByteBuf buf, ProtocolConstants.Direction direction, int protocolVersion)
+    {
+        int len = readVarInt( buf );
+        links = new Link[ len ];
+        for ( int i = 0; i < len; i++ )
+        {
+            Either<LinkType, BaseComponent> type;
+            if ( buf.readBoolean() )
+            {
+                type = Either.left( LinkType.values()[readVarInt( buf )] );
+            } else
+            {
+                type = Either.right( readBaseComponent( buf, protocolVersion ) );
+            }
+            String url = readString( buf );
+
+            links[i] = new Link( type, url );
+        }
+    }
+
+    @Override
+    public void write(ByteBuf buf, ProtocolConstants.Direction direction, int protocolVersion)
+    {
+        writeVarInt( links.length, buf );
+        for ( Link link : links )
+        {
+            Either<LinkType, BaseComponent> type = link.getType();
+            if ( type.isLeft() )
+            {
+                buf.writeBoolean( true );
+                writeVarInt( type.getLeft().ordinal(), buf );
+            } else
+            {
+                buf.writeBoolean( false );
+                writeBaseComponent( type.getRight(), buf, protocolVersion );
+            }
+            writeString( link.getUrl(), buf );
+        }
+    }
+
+    @Override
+    public void handle(AbstractPacketHandler handler) throws Exception
+    {
+        handler.handle( this );
+    }
+
+    public enum LinkType
+    {
+
+        REPORT_BUG,
+        COMMUNITY_GUIDELINES,
+        SUPPORT,
+        STATUS,
+        FEEDBACK,
+        COMMUNITY,
+        WEBSITE,
+        FORUMS,
+        NEWS,
+        ANNOUNCEMENTS;
+    }
+
+    @Data
+    public static class Link
+    {
+
+        private final Either<LinkType, BaseComponent> type;
+        private final String url;
+    }
+}

proxy/pom.xml

@@ -6,13 +6,13 @@
     <parent>
         <groupId>net.md-5</groupId>
         <artifactId>bungeecord-parent</artifactId>
-        <version>1.20-R0.3-SNAPSHOT</version>
+        <version>1.21-R0.1-SNAPSHOT</version>
         <relativePath>../pom.xml</relativePath>
     </parent>
 
     <groupId>net.md-5</groupId>
     <artifactId>bungeecord-proxy</artifactId>
-    <version>1.20-R0.3-SNAPSHOT</version>
+    <version>1.21-R0.1-SNAPSHOT</version>
     <packaging>jar</packaging>
 
     <name>BungeeCord-Proxy</name>
@@ -108,7 +108,7 @@
         <dependency>
             <groupId>com.mysql</groupId>
             <artifactId>mysql-connector-j</artifactId>
-            <version>8.3.0</version>
+            <version>8.4.0</version>
             <scope>runtime</scope>
         </dependency>
         <!-- add these back in as they are not exposed by the API -->

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

@@ -103,7 +103,7 @@ public class DownstreamBridge extends PacketHandler
         {
             server.setObsolete( true );
             con.connectNow( def, ServerConnectEvent.Reason.SERVER_DOWN_REDIRECT );
-            con.sendMessage( bungee.getTranslation( "server_went_down" ) );
+            con.sendMessage( bungee.getTranslation( "server_went_down", def.getName() ) );
         } else
         {
             con.disconnect( Util.exception( t ) );
@@ -120,13 +120,25 @@ public class DownstreamBridge extends PacketHandler
             bungee.getReconnectHandler().setServer( con );
         }
 
-        if ( !server.isObsolete() )
+        ServerDisconnectEvent serverDisconnectEvent = new ServerDisconnectEvent( con, server.getInfo() );
+        bungee.getPluginManager().callEvent( serverDisconnectEvent );
+
+        if ( server.isObsolete() )
+        {
+            // do not perform any actions if the user has already moved
+            return;
+        }
+
+        ServerInfo def = con.updateAndGetNextServer( server.getInfo() );
+        if ( def != null )
+        {
+            server.setObsolete( true );
+            con.connectNow( def, ServerConnectEvent.Reason.SERVER_DOWN_REDIRECT );
+            con.sendMessage( bungee.getTranslation( "server_went_down", def.getName() ) );
+        } else
         {
             con.disconnect( bungee.getTranslation( "lost_connection" ) );
         }
-
-        ServerDisconnectEvent serverDisconnectEvent = new ServerDisconnectEvent( con, server.getInfo() );
-        bungee.getPluginManager().callEvent( serverDisconnectEvent );
     }
 
     @Override

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

@@ -87,6 +87,7 @@ public abstract class EntityMap
             case ProtocolConstants.MINECRAFT_1_20_3:
                 return EntityMap_1_16_2.INSTANCE_1_20_3;
             case ProtocolConstants.MINECRAFT_1_20_5:
+            case ProtocolConstants.MINECRAFT_1_21:
                 return EntityMap_1_16_2.INSTANCE_1_20_5;
         }
         throw new RuntimeException( "Version " + version + " has no entity map" );

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

@@ -30,6 +30,7 @@ public class HandlerBoss extends ChannelInboundHandlerAdapter
 
     private ChannelWrapper channel;
     private PacketHandler handler;
+    private boolean healthCheck;
 
     public void setHandler(PacketHandler handler)
     {
@@ -96,7 +97,7 @@ public class HandlerBoss extends ChannelInboundHandlerAdapter
                     channel.setRemoteAddress( newAddress );
                 } else
                 {
-                    channel.close();
+                    healthCheck = true;
                 }
             } finally
             {
@@ -146,7 +147,7 @@ public class HandlerBoss extends ChannelInboundHandlerAdapter
     {
         if ( ctx.channel().isActive() )
         {
-            boolean logExceptions = !( handler instanceof PingHandler );
+            boolean logExceptions = !( handler instanceof PingHandler ) && !healthCheck;
 
             if ( logExceptions )
             {

query/pom.xml

@@ -6,13 +6,13 @@
     <parent>
         <groupId>net.md-5</groupId>
         <artifactId>bungeecord-parent</artifactId>
-        <version>1.20-R0.3-SNAPSHOT</version>
+        <version>1.21-R0.1-SNAPSHOT</version>
         <relativePath>../pom.xml</relativePath>
     </parent>
 
     <groupId>net.md-5</groupId>
     <artifactId>bungeecord-query</artifactId>
-    <version>1.20-R0.3-SNAPSHOT</version>
+    <version>1.21-R0.1-SNAPSHOT</version>
     <packaging>jar</packaging>
 
     <name>BungeeCord-Query</name>

slf4j/pom.xml

@@ -6,13 +6,13 @@
     <parent>
         <groupId>net.md-5</groupId>
         <artifactId>bungeecord-parent</artifactId>
-        <version>1.20-R0.3-SNAPSHOT</version>
+        <version>1.21-R0.1-SNAPSHOT</version>
         <relativePath>../pom.xml</relativePath>
     </parent>
 
     <groupId>net.md-5</groupId>
     <artifactId>bungeecord-slf4j</artifactId>
-    <version>1.20-R0.3-SNAPSHOT</version>
+    <version>1.21-R0.1-SNAPSHOT</version>
     <packaging>jar</packaging>
 
     <name>BungeeCord-SLF4J</name>