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.opendaylight.openflowjava.protocol.impl.util.ByteBufUtils;
12 import org.slf4j.Logger;
13 import org.slf4j.LoggerFactory;
16 * Decodes incoming messages into message frames.
17 * @author michal.polkorab
19 public class OFFrameDecoder extends ByteToMessageDecoder {
21 /** Length of OpenFlow 1.3 header */
22 public static final byte LENGTH_OF_HEADER = 8;
23 private static final byte LENGTH_INDEX_IN_HEADER = 2;
24 private static final Logger LOGGER = LoggerFactory.getLogger(OFFrameDecoder.class);
27 * Constructor of class.
29 public OFFrameDecoder() {
30 LOGGER.debug("Creating OFFrameDecoder");
34 public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
35 LOGGER.warn("Unexpected exception from downstream.", cause);
40 protected void decode(ChannelHandlerContext chc, ByteBuf bb, List<Object> list) throws Exception {
41 int readableBytes = bb.readableBytes();
42 if (readableBytes < LENGTH_OF_HEADER) {
43 LOGGER.debug("skipping bb - too few data for header: " + readableBytes);
47 int length = bb.getUnsignedShort(bb.readerIndex() + LENGTH_INDEX_IN_HEADER);
48 LOGGER.debug("length of actual message: {}", length);
50 if (readableBytes < length) {
51 if (LOGGER.isDebugEnabled()) {
52 LOGGER.debug("skipping bb - too few data for msg: " +
53 readableBytes + " < " + length);
54 LOGGER.debug("bb: " + ByteBufUtils.byteBufToHexString(bb));
55 LOGGER.debug("readableBytes: " + readableBytes);
60 LOGGER.debug("[enough bytes] readableBytes: " + readableBytes);
62 LOGGER.info("OF Protocol message received, type:{}", bb.getByte(bb.readerIndex() + 1));
64 ByteBuf messageBuffer = bb.slice(bb.readerIndex(), length);
65 list.add(messageBuffer);
66 messageBuffer.retain();