| /* |
| * 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 SUBTYPE_ECHO_REPLY = 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; |
| } |
| |
| @Override |
| public IPacket deserialize(final byte[] data, final int offset, |
| final int length) { |
| final ByteBuffer bb = ByteBuffer.wrap(data, offset, length); |
| this.icmpType = bb.get(); |
| this.icmpCode = bb.get(); |
| this.checksum = bb.getShort(); |
| |
| this.payload = new Data(); |
| this.payload = this.payload.deserialize(data, bb.position(), bb.limit() |
| - bb.position()); |
| this.payload.setParent(this); |
| return this; |
| } |
| |
| /* |
| * (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<ICMP> 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(); |
| |
| icmp.payload = Data.deserializer() |
| .deserialize(data, bb.position(), bb.limit() |
| - bb.position()); |
| 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.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.SUBTYPE_ECHO_REPLY); |
| icmpReply.setChecksum((short) 0); |
| ipReply.setPayload(icmpReply); |
| |
| ethReply.setEtherType(Ethernet.TYPE_IPV4); |
| ethReply.setVlanID(ethRequest.getVlanID()); |
| ethReply.setDestinationMACAddress(ethRequest.getSourceMACAddress()); |
| ethReply.setSourceMACAddress(ethRequest.getDestinationMACAddress()); |
| ethReply.setPayload(ipReply); |
| |
| |
| return ethReply; |
| } |
| } |