org.onlab.packet.ICMP Maven / Gradle / Ivy
/*
* Copyright 2014-present Open Networking Foundation
*
* 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.onlab.packet;
import java.nio.ByteBuffer;
import static com.google.common.base.MoreObjects.toStringHelper;
import static org.onlab.packet.PacketUtils.*;
/**
* Implements ICMP packet format.
*/
public class ICMP extends BasePacket {
protected byte icmpType;
protected byte icmpCode;
protected short checksum;
public static final byte TYPE_ECHO_REQUEST = 0x08;
public static final byte TYPE_ECHO_REPLY = 0x00;
public static final byte CODE_ECHO_REPLY = 0x00;
public static final byte CODE_ECHO_REQEUST = 0x00;
public static final short ICMP_HEADER_LENGTH = 4;
/**
* @return the icmpType
*/
public byte getIcmpType() {
return this.icmpType;
}
/**
* @param icmpType to set
* @return this
*/
public ICMP setIcmpType(final byte icmpType) {
this.icmpType = icmpType;
return this;
}
/**
* @return the icmp code
*/
public byte getIcmpCode() {
return this.icmpCode;
}
/**
* @param icmpCode code to set
* @return this
*/
public ICMP setIcmpCode(final byte icmpCode) {
this.icmpCode = icmpCode;
return this;
}
/**
* @return the checksum
*/
public short getChecksum() {
return this.checksum;
}
/**
* @param checksum the checksum to set
* @return this
*/
public ICMP setChecksum(final short checksum) {
this.checksum = checksum;
return this;
}
/**
* Serializes the packet. Will compute and set the following fields if they
* are set to specific values at the time serialize is called: -checksum : 0
* -length : 0
*/
@Override
public byte[] serialize() {
int length = 4;
byte[] payloadData = null;
if (this.payload != null) {
this.payload.setParent(this);
payloadData = this.payload.serialize();
length += payloadData.length;
}
final byte[] data = new byte[length];
final ByteBuffer bb = ByteBuffer.wrap(data);
bb.put(this.icmpType);
bb.put(this.icmpCode);
bb.putShort(this.checksum);
if (payloadData != null) {
bb.put(payloadData);
}
if (this.parent != null && this.parent instanceof IPv4) {
((IPv4) this.parent).setProtocol(IPv4.PROTOCOL_ICMP);
}
// compute checksum if needed
if (this.checksum == 0) {
bb.rewind();
int accumulation = 0;
for (int i = 0; i < length / 2; ++i) {
accumulation += 0xffff & bb.getShort();
}
// pad to an even number of shorts
if (length % 2 > 0) {
accumulation += (bb.get() & 0xff) << 8;
}
accumulation = (accumulation >> 16 & 0xffff)
+ (accumulation & 0xffff);
this.checksum = (short) (~accumulation & 0xffff);
bb.putShort(2, this.checksum);
}
return data;
}
/*
* (non-Javadoc)
*
* @see java.lang.Object#hashCode()
*/
@Override
public int hashCode() {
final int prime = 5807;
int result = super.hashCode();
result = prime * result + this.icmpType;
result = prime * result + this.icmpCode;
result = prime * result + this.checksum;
return result;
}
/*
* (non-Javadoc)
*
* @see java.lang.Object#equals(java.lang.Object)
*/
@Override
public boolean equals(final Object obj) {
if (this == obj) {
return true;
}
if (!super.equals(obj)) {
return false;
}
if (!(obj instanceof ICMP)) {
return false;
}
final ICMP other = (ICMP) obj;
if (this.icmpType != other.icmpType) {
return false;
}
if (this.icmpCode != other.icmpCode) {
return false;
}
if (this.checksum != other.checksum) {
return false;
}
return true;
}
/**
* Deserializer function for ICMP packets.
*
* @return deserializer function
*/
public static Deserializer deserializer() {
return (data, offset, length) -> {
checkInput(data, offset, length, ICMP_HEADER_LENGTH);
ICMP icmp = new ICMP();
final ByteBuffer bb = ByteBuffer.wrap(data, offset, length);
icmp.icmpType = bb.get();
icmp.icmpCode = bb.get();
icmp.checksum = bb.getShort();
switch (icmp.icmpType) {
case ICMP.TYPE_ECHO_REQUEST:
case ICMP.TYPE_ECHO_REPLY:
Deserializer deserializer = ICMPEcho.deserializer();
icmp.payload = deserializer.deserialize(data, bb.position(), ICMPEcho.ICMP_ECHO_HEADER_LENGTH);
bb.position(bb.position() + ICMPEcho.ICMP_ECHO_HEADER_LENGTH);
icmp.payload.setPayload(Data.deserializer().deserialize(
data,
bb.position(),
bb.limit()
- bb.position()
));
break;
default:
icmp.payload = Data.deserializer()
.deserialize(data, bb.position(), bb.limit()
- bb.position());
break;
}
icmp.payload.setParent(icmp);
return icmp;
};
}
@Override
public String toString() {
return toStringHelper(getClass())
.add("icmpType", Byte.toString(icmpType))
.add("icmpCode", Byte.toString(icmpCode))
.add("checksum", Short.toString(checksum))
.toString();
}
/**
* Builds an ICMP reply using the supplied ICMP request.
*
* @param ethRequest the Ethernet packet containing the ICMP ECHO request
* @return the Ethernet packet containing the ICMP ECHO reply
*/
public static Ethernet buildIcmpReply(Ethernet ethRequest) {
if (ethRequest.getEtherType() != Ethernet.TYPE_IPV4) {
return null;
}
IPv4 ipRequest = (IPv4) ethRequest.getPayload();
if (ipRequest.getProtocol() != IPv4.PROTOCOL_ICMP) {
return null;
}
Ethernet ethReply = new Ethernet();
IPv4 ipReply = new IPv4();
int destAddress = ipRequest.getDestinationAddress();
ipReply.setDestinationAddress(ipRequest.getSourceAddress());
ipReply.setSourceAddress(destAddress);
ipReply.setTtl((byte) 64);
ipReply.setDiffServ(ipRequest.getDiffServ());
ipReply.setChecksum((short) 0);
ipReply.setProtocol(IPv4.PROTOCOL_ICMP);
ICMP icmpRequest = (ICMP) ipRequest.getPayload();
ICMP icmpReply = new ICMP();
icmpReply.setPayload(icmpRequest.getPayload());
icmpReply.setIcmpType(ICMP.TYPE_ECHO_REPLY);
icmpReply.setIcmpCode(ICMP.CODE_ECHO_REPLY);
icmpReply.setChecksum((short) 0);
ipReply.setPayload(icmpReply);
ethReply.setEtherType(Ethernet.TYPE_IPV4);
ethReply.setQinQVID(ethRequest.getQinQVID());
ethReply.setQinQTPID(ethRequest.getQinQTPID());
ethReply.setVlanID(ethRequest.getVlanID());
ethReply.setDestinationMACAddress(ethRequest.getSourceMACAddress());
ethReply.setSourceMACAddress(ethRequest.getDestinationMACAddress());
ethReply.setPayload(ipReply);
return ethReply;
}
}