/*
* Copyright 2014 Anton Tananaev (anton@traccar.org)
*
* 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.traccar.protocol;
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;
public class OrionFrameDecoder extends FrameDecoder {
@Override
protected Object decode(
ChannelHandlerContext ctx,
Channel channel,
ChannelBuffer buf) throws Exception {
int length = 6;
if (buf.readableBytes() >= length) {
int type = buf.getUnsignedByte(buf.readerIndex() + 2) & 0x0f;
if (type == OrionProtocolDecoder.MSG_USERLOG && buf.readableBytes() >= length + 5) {
int index = buf.readerIndex() + 3;
int count = buf.getUnsignedByte(index) & 0x0f;
index += 5;
length += 5;
for (int i = 0; i < count; i++) {
if (buf.readableBytes() < length) {
return null;
}
int logLength = buf.getUnsignedByte(index + 1);
index += logLength;
length += logLength;
}
if (buf.readableBytes() >= length) {
return buf.readBytes(length);
}
} else if (type == OrionProtocolDecoder.MSG_SYSLOG && buf.readableBytes() >= length + 12) {
length += buf.getUnsignedShort(buf.readerIndex() + 8);
if (buf.readableBytes() >= length) {
return buf.readBytes(length);
}
}
}
return null;
}
}