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/*
* Copyright 2014-2015 Open Networking Laboratory
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.onosproject.routing.bgp;
import org.jboss.netty.buffer.ChannelBuffer;
import org.jboss.netty.channel.Channel;
import org.jboss.netty.channel.ChannelHandlerContext;
import org.jboss.netty.handler.codec.frame.FrameDecoder;
import org.onlab.packet.Ip4Address;
import java.util.concurrent.CountDownLatch;
/**
* Class for handling the decoding of the BGP messages at the remote
* BGP peer session.
*/
class TestBgpPeerFrameDecoder extends FrameDecoder {
final BgpSessionInfo remoteInfo = new BgpSessionInfo();
final CountDownLatch receivedOpenMessageLatch = new CountDownLatch(1);
final CountDownLatch receivedKeepaliveMessageLatch = new CountDownLatch(1);
@Override
protected Object decode(ChannelHandlerContext ctx,
Channel channel,
ChannelBuffer buf) throws Exception {
// Test for minimum length of the BGP message
if (buf.readableBytes() < BgpConstants.BGP_HEADER_LENGTH) {
// No enough data received
return null;
}
//
// Mark the current buffer position in case we haven't received
// the whole message.
//
buf.markReaderIndex();
//
// Read and check the BGP message Marker field: it must be all ones
//
byte[] marker = new byte[BgpConstants.BGP_HEADER_MARKER_LENGTH];
buf.readBytes(marker);
for (int i = 0; i < marker.length; i++) {
if (marker[i] != (byte) 0xff) {
// ERROR: Connection Not Synchronized. Close the channel.
ctx.getChannel().close();
return null;
}
}
//
// Read and check the BGP message Length field
//
int length = buf.readUnsignedShort();
if ((length < BgpConstants.BGP_HEADER_LENGTH) ||
(length > BgpConstants.BGP_MESSAGE_MAX_LENGTH)) {
// ERROR: Bad Message Length. Close the channel.
ctx.getChannel().close();
return null;
}
//
// Test whether the rest of the message is received:
// So far we have read the Marker (16 octets) and the
// Length (2 octets) fields.
//
int remainingMessageLen =
length - BgpConstants.BGP_HEADER_MARKER_LENGTH - 2;
if (buf.readableBytes() < remainingMessageLen) {
// No enough data received
buf.resetReaderIndex();
return null;
}
//
// Read the BGP message Type field, and process based on that type
//
int type = buf.readUnsignedByte();
remainingMessageLen--; // Adjust after reading the type
ChannelBuffer message = buf.readBytes(remainingMessageLen);
//
// Process the remaining of the message based on the message type
//
switch (type) {
case BgpConstants.BGP_TYPE_OPEN:
processBgpOpen(ctx, message);
break;
case BgpConstants.BGP_TYPE_UPDATE:
// NOTE: Not used as part of the test, because ONOS does not
// originate UPDATE messages.
break;
case BgpConstants.BGP_TYPE_NOTIFICATION:
// NOTE: Not used as part of the testing (yet)
break;
case BgpConstants.BGP_TYPE_KEEPALIVE:
processBgpKeepalive(ctx, message);
break;
default:
// ERROR: Bad Message Type. Close the channel.
ctx.getChannel().close();
return null;
}
return null;
}
/**
* Processes BGP OPEN message.
*
* @param ctx the Channel Handler Context.
* @param message the message to process.
*/
private void processBgpOpen(ChannelHandlerContext ctx,
ChannelBuffer message) {
int minLength =
BgpConstants.BGP_OPEN_MIN_LENGTH - BgpConstants.BGP_HEADER_LENGTH;
if (message.readableBytes() < minLength) {
// ERROR: Bad Message Length. Close the channel.
ctx.getChannel().close();
return;
}
//
// Parse the OPEN message
//
remoteInfo.setBgpVersion(message.readUnsignedByte());
remoteInfo.setAsNumber(message.readUnsignedShort());
remoteInfo.setHoldtime(message.readUnsignedShort());
remoteInfo.setBgpId(Ip4Address.valueOf((int) message.readUnsignedInt()));
// Optional Parameters
int optParamLen = message.readUnsignedByte();
if (message.readableBytes() < optParamLen) {
// ERROR: Bad Message Length. Close the channel.
ctx.getChannel().close();
return;
}
message.readBytes(optParamLen); // NOTE: data ignored
// BGP OPEN message successfully received
receivedOpenMessageLatch.countDown();
}
/**
* Processes BGP KEEPALIVE message.
*
* @param ctx the Channel Handler Context.
* @param message the message to process.
*/
private void processBgpKeepalive(ChannelHandlerContext ctx,
ChannelBuffer message) {
if (message.readableBytes() + BgpConstants.BGP_HEADER_LENGTH !=
BgpConstants.BGP_KEEPALIVE_EXPECTED_LENGTH) {
// ERROR: Bad Message Length. Close the channel.
ctx.getChannel().close();
return;
}
// BGP KEEPALIVE message successfully received
receivedKeepaliveMessageLatch.countDown();
}
}
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