Correctly pass velocity native compressor (#11509)

patches/server/0980-Use-Velocity-compression-and-cipher-natives.patch

@@ -3,6 +3,8 @@ From: Andrew Steinborn <git@steinborn.me>
 Date: Mon, 26 Jul 2021 02:15:17 -0400
 Subject: [PATCH] Use Velocity compression and cipher natives
 
+== AT ==
+private-f net.minecraft.network.CompressionDecoder inflater
 
 diff --git a/build.gradle.kts b/build.gradle.kts
 index 25001d6cf4f70bd01ab304625b49ec45f5b1f525..9966576652ed6007d2228237f292c1dc83ede485 100644
@@ -102,18 +104,19 @@ index 0f3d502a9680006bcdcd7d272240a2e5c3b46790..ffa1c48585fbbc1d30826d435043527f
 +    // Paper end - Use Velocity cipher
  }
 diff --git a/src/main/java/net/minecraft/network/CompressionDecoder.java b/src/main/java/net/minecraft/network/CompressionDecoder.java
-index 5927c928b27f64bd3973e95d5867b59f67476d41..ba3619b03ea73e4ea55ae2eb79d3b6cd1f48a191 100644
+index a57e8516b3fafd7060dc1b30550164e74e17fc84..3a853d7401a8275b1a3d525bbda8095de12d0038 100644
 --- a/src/main/java/net/minecraft/network/CompressionDecoder.java
 +++ b/src/main/java/net/minecraft/network/CompressionDecoder.java
-@@ -13,13 +13,20 @@ public class CompressionDecoder extends ByteToMessageDecoder {
+@@ -13,13 +13,21 @@ public class CompressionDecoder extends ByteToMessageDecoder {
      public static final int MAXIMUM_COMPRESSED_LENGTH = 2097152;
      public static final int MAXIMUM_UNCOMPRESSED_LENGTH = 8388608;
-     private final Inflater inflater;
+     private Inflater inflater;
 +    private com.velocitypowered.natives.compression.VelocityCompressor compressor; // Paper - Use Velocity cipher
      private int threshold;
      private boolean validateDecompressed;
  
 +    // Paper start - Use Velocity cipher
++    @io.papermc.paper.annotation.DoNotUse
      public CompressionDecoder(int compressionThreshold, boolean rejectsBadPackets) {
 +        this(null, compressionThreshold, rejectsBadPackets);
 +    }
@@ -127,7 +130,7 @@ index 5927c928b27f64bd3973e95d5867b59f67476d41..ba3619b03ea73e4ea55ae2eb79d3b6cd
      }
  
      protected void decode(ChannelHandlerContext channelHandlerContext, ByteBuf byteBuf, List<Object> list) throws Exception {
-@@ -38,14 +45,42 @@ public class CompressionDecoder extends ByteToMessageDecoder {
+@@ -38,14 +46,42 @@ public class CompressionDecoder extends ByteToMessageDecoder {
                      }
                  }
  
@@ -170,12 +173,18 @@ index 5927c928b27f64bd3973e95d5867b59f67476d41..ba3619b03ea73e4ea55ae2eb79d3b6cd
      private void setupInflaterInput(ByteBuf buf) {
          ByteBuffer byteBuffer;
          if (buf.nioBufferCount() > 0) {
-@@ -82,7 +117,7 @@ public class CompressionDecoder extends ByteToMessageDecoder {
+@@ -82,7 +118,13 @@ public class CompressionDecoder extends ByteToMessageDecoder {
          }
      }
  
 -    public void setThreshold(int compressionThreshold, boolean rejectsBadPackets) {
-+    public void setThreshold(com.velocitypowered.natives.compression.VelocityCompressor compressor, int compressionThreshold, boolean rejectsBadPackets) { // Paper - Use Velocity cipher
++    // Paper start - Use Velocity cipher
++    public void setThreshold(com.velocitypowered.natives.compression.VelocityCompressor compressor, int compressionThreshold, boolean rejectsBadPackets) {
++        if (this.compressor == null && compressor != null) { // Only re-configure once. Re-reconfiguring would require closing the native compressor.
++            this.compressor = compressor;
++            this.inflater = null;
++        }
++    // Paper end - Use Velocity cipher
          this.threshold = compressionThreshold;
          this.validateDecompressed = rejectsBadPackets;
      }
@@ -275,7 +284,7 @@ index 34a80d2f34555663ab1b394972957089214cb337..ec30c291188ac3bba7f1c3bc397576d1
          return this.threshold;
      }
 diff --git a/src/main/java/net/minecraft/network/Connection.java b/src/main/java/net/minecraft/network/Connection.java
-index 7dc7aeb1d94d26cf54bd4e4ab13972a3a60c1f98..90a2c61c42cba7e38f167eccdd7a951a947963c4 100644
+index 7dc7aeb1d94d26cf54bd4e4ab13972a3a60c1f98..36624d3dc7e3f2a64f88b01c5e906018fcee0015 100644
 --- a/src/main/java/net/minecraft/network/Connection.java
 +++ b/src/main/java/net/minecraft/network/Connection.java
 @@ -792,11 +792,28 @@ public class Connection extends SimpleChannelInboundHandler<Packet<?>> {
@@ -311,7 +320,7 @@ index 7dc7aeb1d94d26cf54bd4e4ab13972a3a60c1f98..90a2c61c42cba7e38f167eccdd7a951a
  
      public boolean isEncrypted() {
          return this.encrypted;
-@@ -829,12 +846,13 @@ public class Connection extends SimpleChannelInboundHandler<Packet<?>> {
+@@ -829,14 +846,15 @@ public class Connection extends SimpleChannelInboundHandler<Packet<?>> {
  
      public void setupCompression(int compressionThreshold, boolean rejectsBadPackets) {
          if (compressionThreshold >= 0) {
@@ -324,8 +333,11 @@ index 7dc7aeb1d94d26cf54bd4e4ab13972a3a60c1f98..90a2c61c42cba7e38f167eccdd7a951a
 -                packetdecompressor.setThreshold(compressionThreshold, rejectsBadPackets);
 +                packetdecompressor.setThreshold(compressor, compressionThreshold, rejectsBadPackets); // Paper - Use Velocity cipher
              } else {
-                 this.channel.pipeline().addAfter("splitter", "decompress", new CompressionDecoder(compressionThreshold, rejectsBadPackets));
+-                this.channel.pipeline().addAfter("splitter", "decompress", new CompressionDecoder(compressionThreshold, rejectsBadPackets));
++                this.channel.pipeline().addAfter("splitter", "decompress", new CompressionDecoder(compressor, compressionThreshold, rejectsBadPackets)); // Paper - Use Velocity cipher
              }
+ 
+             channelhandler = this.channel.pipeline().get("compress");
 @@ -845,7 +863,7 @@ public class Connection extends SimpleChannelInboundHandler<Packet<?>> {
  
                  packetcompressor.setThreshold(compressionThreshold);