1 /* Copyright (C)2013 Pantheon Technologies, s.r.o. All rights reserved. */
3 package org.opendaylight.openflowjava.protocol.impl.core;
5 import io.netty.buffer.ByteBuf;
6 import io.netty.channel.ChannelHandlerContext;
7 import io.netty.handler.codec.ByteToMessageDecoder;
11 import org.slf4j.Logger;
12 import org.slf4j.LoggerFactory;
15 * Decodes incoming messages into message frames.
16 * @author michal.polkorab
18 public class OFFrameDecoder extends ByteToMessageDecoder {
20 /** Length of OpenFlow 1.3 header */
21 public static final byte LENGTH_OF_HEADER = 8;
22 private static final byte LENGTH_INDEX_IN_HEADER = 2;
23 private static final Logger LOGGER = LoggerFactory.getLogger(OFFrameDecoder.class);
26 * Constructor of class.
28 public OFFrameDecoder() {
29 LOGGER.debug("Creating OFFrameDecoder");
33 public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
34 LOGGER.warn("Unexpected exception from downstream.", cause);
39 protected void decode(ChannelHandlerContext chc, ByteBuf bb, List<Object> list) throws Exception {
40 if (bb.readableBytes() < LENGTH_OF_HEADER) {
41 LOGGER.debug("skipping bb - too few data for header: " + bb.readableBytes());
45 int length = bb.getUnsignedShort(LENGTH_INDEX_IN_HEADER);
46 if (bb.readableBytes() < length) {
47 LOGGER.debug("skipping bb - too few data for msg: " +
48 bb.readableBytes() + " < " + length);
51 LOGGER.info("OF Protocol message received, type:{}", bb.getByte(1));
53 ByteBuf messageBuffer = bb.slice(bb.readerIndex(), length);
54 list.add(messageBuffer);
55 messageBuffer.retain();