Fix context and window sizes sides. (#8395)

Motivation:

As mentioned in RFC 7692 :

The "server_no_context_takeover" Extension Parameter should be used on server side for compression and on client side for decompression.

The "client_no_context_takeover" Extension Parameter should be used on client side for compression and on server side for decompression.

Right now, in PerMessageDeflateClientExtensionHandshaker, the decoder uses clientNoContext instead of serverNoContext and the encoder uses serverNoContext instead of clientNoContext.

The same inversion is present in PerMessageDeflateServerExtensionHandshaker: the decoder uses
serverNoContext instead of clientNoContext, while the encoder uses serverNoContext instead of clientNoContext. Besides the context inversion, the sliding window sizes seem to be inversed as well.

Modification:

Inverse clientNoContext with serverNoContext and clientWindowSize with serverWindowSize for both the Decoder and Encoder in PerMessageDeflateServerExtensionHandshaker and PerMessageDeflateClientExtensionHandshaker.

Result:

This fixes the decompression fail in the case that one of the contexts is set and the other one is not.

codec-http/src/main/java/io/netty/handler/codec/http/websocketx/extensions/compression/PerMessageDeflateClientExtensionHandshaker.java

@@ -186,12 +186,12 @@ public final class PerMessageDeflateClientExtensionHandshaker implements WebSock
 
         @Override
         public WebSocketExtensionEncoder newExtensionEncoder() {
-            return new PerMessageDeflateEncoder(compressionLevel, serverWindowSize, serverNoContext);
+            return new PerMessageDeflateEncoder(compressionLevel, clientWindowSize, clientNoContext);
         }
 
         @Override
         public WebSocketExtensionDecoder newExtensionDecoder() {
-            return new PerMessageDeflateDecoder(clientNoContext);
+            return new PerMessageDeflateDecoder(serverNoContext);
         }
     }
 

codec-http/src/main/java/io/netty/handler/codec/http/websocketx/extensions/compression/PerMessageDeflateServerExtensionHandshaker.java

@@ -167,12 +167,12 @@ public final class PerMessageDeflateServerExtensionHandshaker implements WebSock
 
         @Override
         public WebSocketExtensionEncoder newExtensionEncoder() {
-            return new PerMessageDeflateEncoder(compressionLevel, clientWindowSize, clientNoContext);
+            return new PerMessageDeflateEncoder(compressionLevel, serverWindowSize, serverNoContext);
         }
 
         @Override
         public WebSocketExtensionDecoder newExtensionDecoder() {
-            return new PerMessageDeflateDecoder(serverNoContext);
+            return new PerMessageDeflateDecoder(clientNoContext);
         }
 
         @Override

codec-http/src/test/java/io/netty/handler/codec/http/websocketx/extensions/compression/PerFrameDeflateDecoderTest.java

@@ -15,6 +15,8 @@
  */
 package io.netty.handler.codec.http.websocketx.extensions.compression;
 
+import static io.netty.handler.codec.http.websocketx.extensions.WebSocketExtension.RSV1;
+import static io.netty.handler.codec.http.websocketx.extensions.WebSocketExtension.RSV3;
 import static org.junit.Assert.*;
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.Unpooled;
@@ -22,6 +24,7 @@ import io.netty.channel.embedded.EmbeddedChannel;
 import io.netty.handler.codec.compression.ZlibCodecFactory;
 import io.netty.handler.codec.compression.ZlibWrapper;
 import io.netty.handler.codec.http.websocketx.BinaryWebSocketFrame;
+import io.netty.handler.codec.http.websocketx.TextWebSocketFrame;
 import io.netty.handler.codec.http.websocketx.extensions.WebSocketExtension;
 
 import java.util.Arrays;
@@ -47,7 +50,7 @@ public class PerFrameDeflateDecoderTest {
         ByteBuf compressedPayload = encoderChannel.readOutbound();
 
         BinaryWebSocketFrame compressedFrame = new BinaryWebSocketFrame(true,
-                WebSocketExtension.RSV1 | WebSocketExtension.RSV3,
+                RSV1 | RSV3,
                 compressedPayload.slice(0, compressedPayload.readableBytes() - 4));
 
         // execute
@@ -58,7 +61,7 @@ public class PerFrameDeflateDecoderTest {
         assertNotNull(uncompressedFrame);
         assertNotNull(uncompressedFrame.content());
         assertTrue(uncompressedFrame instanceof BinaryWebSocketFrame);
-        assertEquals(WebSocketExtension.RSV3, uncompressedFrame.rsv());
+        assertEquals(RSV3, uncompressedFrame.rsv());
         assertEquals(300, uncompressedFrame.content().readableBytes());
 
         byte[] finalPayload = new byte[300];
@@ -76,7 +79,7 @@ public class PerFrameDeflateDecoderTest {
         random.nextBytes(payload);
 
         BinaryWebSocketFrame frame = new BinaryWebSocketFrame(true,
-                WebSocketExtension.RSV3, Unpooled.wrappedBuffer(payload));
+                RSV3, Unpooled.wrappedBuffer(payload));
 
         // execute
         decoderChannel.writeInbound(frame);
@@ -86,7 +89,7 @@ public class PerFrameDeflateDecoderTest {
         assertNotNull(newFrame);
         assertNotNull(newFrame.content());
         assertTrue(newFrame instanceof BinaryWebSocketFrame);
-        assertEquals(WebSocketExtension.RSV3, newFrame.rsv());
+        assertEquals(RSV3, newFrame.rsv());
         assertEquals(300, newFrame.content().readableBytes());
 
         byte[] finalPayload = new byte[300];
@@ -105,7 +108,7 @@ public class PerFrameDeflateDecoderTest {
         encoderChannel.writeOutbound(Unpooled.EMPTY_BUFFER);
         ByteBuf compressedPayload = encoderChannel.readOutbound();
         BinaryWebSocketFrame compressedFrame =
-                new BinaryWebSocketFrame(true, WebSocketExtension.RSV1 | WebSocketExtension.RSV3, compressedPayload);
+                new BinaryWebSocketFrame(true, RSV1 | RSV3, compressedPayload);
 
         // execute
         decoderChannel.writeInbound(compressedFrame);
@@ -115,9 +118,8 @@ public class PerFrameDeflateDecoderTest {
         assertNotNull(uncompressedFrame);
         assertNotNull(uncompressedFrame.content());
         assertTrue(uncompressedFrame instanceof BinaryWebSocketFrame);
-        assertEquals(WebSocketExtension.RSV3, uncompressedFrame.rsv());
+        assertEquals(RSV3, uncompressedFrame.rsv());
         assertEquals(0, uncompressedFrame.content().readableBytes());
         uncompressedFrame.release();
     }
-
 }

codec-http/src/test/java/io/netty/handler/codec/http/websocketx/extensions/compression/PerMessageDeflateClientExtensionHandshakerTest.java

@@ -15,11 +15,15 @@
  */
 package io.netty.handler.codec.http.websocketx.extensions.compression;
 
+import static io.netty.handler.codec.http.websocketx.extensions.WebSocketExtension.RSV1;
 import static io.netty.handler.codec.http.websocketx.extensions.compression.
         PerMessageDeflateServerExtensionHandshaker.*;
 import static org.junit.Assert.*;
 
+import io.netty.buffer.Unpooled;
+import io.netty.channel.embedded.EmbeddedChannel;
 import io.netty.handler.codec.compression.ZlibCodecFactory;
+import io.netty.handler.codec.http.websocketx.TextWebSocketFrame;
 import io.netty.handler.codec.http.websocketx.extensions.WebSocketClientExtension;
 import io.netty.handler.codec.http.websocketx.extensions.WebSocketExtensionData;
 
@@ -66,7 +70,7 @@ public class PerMessageDeflateClientExtensionHandshakerTest {
                 new WebSocketExtensionData(PERMESSAGE_DEFLATE_EXTENSION, Collections.<String, String>emptyMap()));
 
         assertNotNull(extension);
-        assertEquals(WebSocketClientExtension.RSV1, extension.rsv());
+        assertEquals(RSV1, extension.rsv());
         assertTrue(extension.newExtensionDecoder() instanceof PerMessageDeflateDecoder);
         assertTrue(extension.newExtensionEncoder() instanceof PerMessageDeflateEncoder);
     }
@@ -92,7 +96,7 @@ public class PerMessageDeflateClientExtensionHandshakerTest {
 
         // test
         assertNotNull(extension);
-        assertEquals(WebSocketClientExtension.RSV1, extension.rsv());
+        assertEquals(RSV1, extension.rsv());
         assertTrue(extension.newExtensionDecoder() instanceof PerMessageDeflateDecoder);
         assertTrue(extension.newExtensionEncoder() instanceof PerMessageDeflateEncoder);
 
@@ -107,7 +111,7 @@ public class PerMessageDeflateClientExtensionHandshakerTest {
 
         // test
         assertNotNull(extension);
-        assertEquals(WebSocketClientExtension.RSV1, extension.rsv());
+        assertEquals(RSV1, extension.rsv());
         assertTrue(extension.newExtensionDecoder() instanceof PerMessageDeflateDecoder);
         assertTrue(extension.newExtensionEncoder() instanceof PerMessageDeflateEncoder);
 
@@ -121,4 +125,61 @@ public class PerMessageDeflateClientExtensionHandshakerTest {
         // test
         assertNull(extension);
     }
+
+    @Test
+    public void testDecoderNoClientContext() {
+        PerMessageDeflateClientExtensionHandshaker handshaker =
+                new PerMessageDeflateClientExtensionHandshaker(6, true, MAX_WINDOW_SIZE, true, false);
+
+        byte[] firstPayload = new byte[] {
+                76, -50, -53, 10, -62, 48, 20, 4, -48, 95, 41, 89, -37, 36, 77, 90, 31, -39, 41, -72, 112, 33, -120, 20,
+                20, 119, -79, 70, 123, -95, 121, -48, 92, -116, 80, -6, -17, -58, -99, -37, -31, 12, 51, 19, 1, -9, -12,
+                68, -111, -117, 25, 58, 111, 77, -127, -66, -64, -34, 20, 59, -64, -29, -2, 90, -100, -115, 30, 16, 114,
+                -68, 61, 29, 40, 89, -112, -73, 25, 35, 120, -105, -67, -32, -43, -70, -84, 120, -55, 69, 43, -124, 106,
+                -92, 18, -110, 114, -50, 111, 25, -3, 10, 17, -75, 13, 127, -84, 106, 90, -66, 84, -75, 84, 53, -89,
+                -75, 92, -3, -40, -61, 119, 49, -117, 30, 49, 68, -59, 88, 74, -119, -34, 1, -83, -7, -48, 124, -124,
+                -23, 16, 88, -118, 121, 54, -53, 1, 44, 32, 81, 19, 25, -115, -43, -32, -64, -67, -120, -110, -101, 121,
+                -2, 2
+        };
+
+        byte[] secondPayload = new byte[] {
+                -86, 86, 42, 46, 77, 78, 78, 45, 6, 26, 83, 82, 84, -102, -86, 3, -28, 38, 21, 39, 23, 101, 38, -91, 2,
+                -51, -51, 47, 74, 73, 45, 114, -54, -49, -49, -10, 49, -78, -118, 112, 10, 9, 13, 118, 1, -102, 84,
+                -108, 90, 88, 10, 116, 27, -56, -84, 124, -112, -13, 16, 26, 116, -108, 18, -117, -46, -127, 6, 69, 99,
+                -45, 24, 91, 91, 11, 0
+        };
+
+        Map<String, String> parameters =  Collections.singletonMap(CLIENT_NO_CONTEXT, null);
+
+        WebSocketClientExtension extension = handshaker.handshakeExtension(
+                new WebSocketExtensionData(PERMESSAGE_DEFLATE_EXTENSION, parameters));
+        assertNotNull(extension);
+
+        EmbeddedChannel decoderChannel = new EmbeddedChannel(extension.newExtensionDecoder());
+        assertTrue(
+                decoderChannel.writeInbound(new TextWebSocketFrame(true, RSV1, Unpooled.copiedBuffer(firstPayload))));
+        TextWebSocketFrame firstFrameDecompressed = decoderChannel.readInbound();
+        assertTrue(
+                decoderChannel.writeInbound(new TextWebSocketFrame(true, RSV1, Unpooled.copiedBuffer(secondPayload))));
+        TextWebSocketFrame secondFrameDecompressed = decoderChannel.readInbound();
+
+        assertNotNull(firstFrameDecompressed);
+        assertNotNull(firstFrameDecompressed.content());
+        assertTrue(firstFrameDecompressed instanceof TextWebSocketFrame);
+        assertEquals(firstFrameDecompressed.text(),
+                     "{\"info\":\"Welcome to the BitMEX Realtime API.\",\"version\"" +
+                     ":\"2018-10-02T22:53:23.000Z\",\"timestamp\":\"2018-10-15T06:43:40.437Z\"," +
+                     "\"docs\":\"https://www.bitmex.com/app/wsAPI\",\"limit\":{\"remaining\":39}}");
+        assertTrue(firstFrameDecompressed.release());
+
+        assertNotNull(secondFrameDecompressed);
+        assertNotNull(secondFrameDecompressed.content());
+        assertTrue(secondFrameDecompressed instanceof TextWebSocketFrame);
+        assertEquals(secondFrameDecompressed.text(),
+                     "{\"success\":true,\"subscribe\":\"orderBookL2:XBTUSD\"," +
+                     "\"request\":{\"op\":\"subscribe\",\"args\":[\"orderBookL2:XBTUSD\"]}}");
+        assertTrue(secondFrameDecompressed.release());
+
+        assertFalse(decoderChannel.finish());
+    }
 }