Fixing Parsing of masking bytes on slow testcase (would read in reverse order under certain conditions)

jetty-util/src/main/java/org/eclipse/jetty/util/BufferUtil.java

@@ -156,7 +156,7 @@ public class BufferUtil
 
     /* ------------------------------------------------------------ */
     /** Flip the buffer to Flush mode.
-     * The limit is set to the first unused byte(the old position) amd
+     * The limit is set to the first unused byte(the old position) and
      * the position is set to the passed position.
      * <p>
      * This method is used as a replacement of {@link Buffer#flip()}.

jetty-websocket/websocket-core/src/main/java/org/eclipse/jetty/websocket/protocol/Parser.java

@@ -392,8 +392,8 @@ public class Parser
                 case MASK_BYTES:
                 {
                     byte b = buffer.get();
+                    frame.getMask()[4 - cursor] = b;
                     --cursor;
-                    frame.getMask()[cursor] = b;
                     if (cursor == 0)
                     {
                         // special case for empty payloads (no more bytes left in buffer)
@@ -449,6 +449,7 @@ public class Parser
                 getPolicy().assertValidPayloadLength(payloadLength);
                 frame.assertValid();
                 payload = ByteBuffer.allocate(payloadLength);
+                BufferUtil.clearToFill(payload);
             }
 
             BufferUtil.put(buffer,payload);
@@ -457,14 +458,18 @@ public class Parser
             {
                 BufferUtil.flipToFlush(payload,0);
 
+                LOG.debug("PreMask: {}",BufferUtil.toDetailString(payload));
                 // demask (if needed)
                 if (frame.isMasked())
                 {
                     byte mask[] = frame.getMask();
+                    int offset;
+                    int start = payload.position();
                     int end = payload.limit();
-                    for (int i = payload.position(); i < end; i++)
+                    for (int i = start; i < end; i++)
                     {
-                        payload.put(i,(byte)(payload.get(i) ^ mask[i % 4]));
+                        offset = (i - start);
+                        payload.put(i,(byte)(payload.get(i) ^ mask[offset % 4]));
                     }
                 }
 

jetty-websocket/websocket-core/src/test/java/org/eclipse/jetty/websocket/protocol/GeneratorTest.java

@@ -17,6 +17,14 @@ import org.junit.Test;
 public class GeneratorTest
 {
 
+    private void parsePartial(Parser parser, ByteBuffer buf, int numBytes)
+    {
+        int len = Math.min(numBytes,buf.remaining());
+        byte arr[] = new byte[len];
+        buf.get(arr,0,len);
+        parser.parse(ByteBuffer.wrap(arr));
+    }
+
     /**
      * Prevent regression of masking of many packets.
      */
@@ -25,7 +33,7 @@ public class GeneratorTest
     {
         byte[] MASK =
             { 0x11, 0x22, 0x33, 0x44 };
-        int pingCount = 1000;
+        int pingCount = 10;
 
         // the generator
         Generator generator = new UnitGenerator();
@@ -67,13 +75,11 @@ public class GeneratorTest
         int segmentSize = 5;
         while (completeBuf.remaining() > 0)
         {
-            ByteBuffer part = completeBuf.slice();
-            int len = Math.min(segmentSize,part.remaining());
-            part.limit(part.position() + len);
-            parser.parse(part);
-            completeBuf.position(completeBuf.position() + len);
+            parsePartial(parser,completeBuf,segmentSize);
         }
 
+        capture.dump();
+
         // Assert validity of frame
         int frameCount = send.size();
         capture.assertFrameCount(frameCount);

jetty-websocket/websocket-core/src/test/resources/jetty-logging.properties

@@ -1,2 +1,3 @@
 org.eclipse.jetty.util.log.class=org.eclipse.jetty.util.log.StdErrLog
-org.eclipse.jetty.websocket.LEVEL=WARN
+org.eclipse.jetty.websocket.LEVEL=WARN
+# org.eclipse.jetty.websocket.protocol.Parser.LEVEL=DEBUG