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/*
* Copyright 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.bgpio.protocol.ver4;
import org.jboss.netty.buffer.ChannelBuffer;
import org.onosproject.bgpio.exceptions.BGPParseException;
import org.onosproject.bgpio.protocol.BGPFactories;
import org.onosproject.bgpio.protocol.BGPMessage;
import org.onosproject.bgpio.protocol.BGPMessageReader;
import org.onosproject.bgpio.types.BGPErrorType;
import org.onosproject.bgpio.types.BGPHeader;
import org.onosproject.bgpio.util.Validation;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Provides BGP messages.
*/
public abstract class BGPMessageVer4 {
protected static final Logger log = LoggerFactory.getLogger(BGPFactories.class);
static final byte OPEN_MSG_TYPE = 0x1;
static final byte KEEPALIVE_MSG_TYPE = 0x4;
static final byte UPDATE_MSG_TYPE = 0x2;
static final byte NOTIFICATION_MSG_TYPE = 0x3;
static final int MINIMUM_COMMON_HEADER_LENGTH = 19;
static final int HEADER_AND_MSG_LEN = 18;
static final int MAXIMUM_PACKET_LENGTH = 4096;
public static final BGPMessageVer4.Reader READER = new Reader();
/**
* Reader class for reading BGP messages from channel buffer.
*
*/
static class Reader implements BGPMessageReader<BGPMessage> {
@Override
public BGPMessage readFrom(ChannelBuffer cb, BGPHeader bgpHeader)
throws BGPParseException {
if (cb.readableBytes() < MINIMUM_COMMON_HEADER_LENGTH) {
log.error("Packet should have minimum length.");
Validation.validateLen(BGPErrorType.MESSAGE_HEADER_ERROR, BGPErrorType.BAD_MESSAGE_LENGTH,
cb.readableBytes());
}
if (cb.readableBytes() > MAXIMUM_PACKET_LENGTH) {
log.error("Packet length should not exceed {}.", MAXIMUM_PACKET_LENGTH);
Validation.validateLen(BGPErrorType.MESSAGE_HEADER_ERROR, BGPErrorType.BAD_MESSAGE_LENGTH,
cb.readableBytes());
}
try {
// fixed value property version == 4
byte[] marker = new byte[BGPHeader.MARKER_LENGTH];
cb.readBytes(marker, 0, BGPHeader.MARKER_LENGTH);
bgpHeader.setMarker(marker);
for (int i = 0; i < BGPHeader.MARKER_LENGTH; i++) {
if (marker[i] != (byte) 0xff) {
throw new BGPParseException(BGPErrorType.MESSAGE_HEADER_ERROR,
BGPErrorType.CONNECTION_NOT_SYNCHRONIZED, null);
}
}
short length = cb.readShort();
if (length != (cb.readableBytes() + HEADER_AND_MSG_LEN)) {
Validation.validateLen(BGPErrorType.MESSAGE_HEADER_ERROR, BGPErrorType.BAD_MESSAGE_LENGTH, length);
}
bgpHeader.setLength(length);
byte type = cb.readByte();
bgpHeader.setType(type);
log.debug("Reading update message of type " + type);
int len = length - MINIMUM_COMMON_HEADER_LENGTH;
switch (type) {
case OPEN_MSG_TYPE:
log.debug("OPEN MESSAGE is received");
return BGPOpenMsgVer4.READER.readFrom(cb.readBytes(len), bgpHeader);
case KEEPALIVE_MSG_TYPE:
log.debug("KEEPALIVE MESSAGE is received");
return BGPKeepaliveMsgVer4.READER.readFrom(cb.readBytes(len), bgpHeader);
case UPDATE_MSG_TYPE:
log.debug("UPDATE MESSAGE is received");
// TODO: Update message version 4
case NOTIFICATION_MSG_TYPE:
log.debug("NOTIFICATION MESSAGE is received");
return BGPNotificationMsgVer4.READER.readFrom(cb.readBytes(len), bgpHeader);
default:
Validation.validateType(BGPErrorType.MESSAGE_HEADER_ERROR, BGPErrorType.BAD_MESSAGE_TYPE, type);
return null;
}
} catch (IndexOutOfBoundsException e) {
throw new BGPParseException(BGPErrorType.MESSAGE_HEADER_ERROR, BGPErrorType.BAD_MESSAGE_LENGTH, null);
}
}
}
}
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