/*
* Copyright 2010 NCHOVY
*
* 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.krakenapps.pcap.decoder.udp;
import java.util.Collection;
import java.util.concurrent.CopyOnWriteArraySet;
import org.krakenapps.pcap.Protocol;
import org.krakenapps.pcap.decoder.ip.Ipv4Packet;
import org.krakenapps.pcap.decoder.ip.IpProcessor;
import org.krakenapps.pcap.decoder.ipv6.Ipv6Packet;
import org.krakenapps.pcap.decoder.ipv6.Ipv6Processor;
import org.krakenapps.pcap.util.Buffer;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* @author mindori
*/
public class UdpDecoder implements IpProcessor, Ipv6Processor {
private final Logger logger = LoggerFactory.getLogger(UdpDecoder.class.getName());
private CopyOnWriteArraySet<UdpProcessor> callbacks = new CopyOnWriteArraySet<UdpProcessor>();
private UdpProtocolMapper protocolMapper;
public UdpDecoder(UdpProtocolMapper protocolMapper) {
this.protocolMapper = protocolMapper;
}
public UdpProtocolMapper getProtocolMapper() {
return protocolMapper;
}
public void setProtocolMapper(UdpProtocolMapper protocolMapper) {
this.protocolMapper = protocolMapper;
}
public void registerUdpProcessor(UdpProcessor processor) {
callbacks.add(processor);
}
public void unregisterUdpProcessor(UdpProcessor processor) {
callbacks.remove(processor);
}
public void process(Ipv4Packet packet) {
Buffer b = packet.getData();
int sourcePort = b.getUnsignedShort();
int destinationPort = b.getUnsignedShort();
UdpPacket newUdp = new UdpPacket(packet, sourcePort, destinationPort);
newUdp.setLength(b.getUnsignedShort());
newUdp.setChecksum(b.getUnsignedShort());
if (logger.isDebugEnabled())
logger.debug(newUdp.toString());
b.discardReadBytes();
newUdp.setData(b);
dispatch(newUdp);
}
@Override
public void process(Ipv6Packet p) {
Buffer b = p.getData();
int sourcePort = b.getUnsignedShort();
int destinationPort = b.getUnsignedShort();
int length = b.getUnsignedShort();
short checksum = b.getShort();
UdpPacket pkt = new UdpPacket(p, sourcePort, destinationPort);
pkt.setLength(length);
pkt.setChecksum(checksum);
b.discardReadBytes();
pkt.setData(b);
dispatch(pkt);
}
private void dispatch(UdpPacket newUdp) {
/* manipulate udp packet from outside */
for (UdpProcessor callback : callbacks) {
try {
callback.process(new UdpPacket(newUdp));
} catch (Exception e) {
e.printStackTrace();
}
}
Protocol protocol = protocolMapper.map(newUdp);
if (protocol == null)
return;
Collection<UdpProcessor> processors = protocolMapper.getUdpProcessors(protocol);
if (processors != null) {
for (UdpProcessor processor : processors) {
try {
processor.process(newUdp);
} catch (Exception e) {
logger.warn("kraken pcap: udp processor should now throw any exception", e);
}
}
}
}
}