/*
* Copyright 2014-present 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.onlab.packet;
import java.nio.ByteBuffer;
import java.util.Arrays;
import static com.google.common.base.MoreObjects.toStringHelper;
import static org.onlab.packet.PacketUtils.*;
/**
* Implements TCP packet format.
*/
public class TCP extends BasePacket {
private static final short TCP_HEADER_LENGTH = 20;
protected int sourcePort;
protected int destinationPort;
protected int sequence;
protected int acknowledge;
protected byte dataOffset;
protected short flags;
protected short windowSize;
protected short checksum;
protected short urgentPointer;
protected byte[] options;
/**
* Gets TCP source port.
*
* @return TCP source port
*/
public int getSourcePort() {
return this.sourcePort;
}
/**
* Sets TCP source port.
*
* @param sourcePort the sourcePort to set (unsigned 16 bits integer)
* @return this
*/
public TCP setSourcePort(final int sourcePort) {
this.sourcePort = sourcePort;
return this;
}
/**
* Gets TCP destination port.
*
* @return the destinationPort
*/
public int getDestinationPort() {
return this.destinationPort;
}
/**
* Sets TCP destination port.
*
* @param destinationPort the destinationPort to set (unsigned 16 bits integer)
* @return this
*/
public TCP setDestinationPort(final int destinationPort) {
this.destinationPort = destinationPort;
return this;
}
/**
* Gets checksum.
*
* @return the checksum
*/
public short getChecksum() {
return this.checksum;
}
/**
* Sets checksum.
*
* @param checksum the checksum to set
* @return this
*/
public TCP setChecksum(final short checksum) {
this.checksum = checksum;
return this;
}
/**
* Gets sequence number.
*
* @return the sequence number
*/
public int getSequence() {
return this.sequence;
}
/**
* Sets sequence number.
*
* @param seq the sequence number to set
* @return this
*/
public TCP setSequence(final int seq) {
this.sequence = seq;
return this;
}
/**
* Gets acknowledge number.
*
* @return the acknowledge number
*/
public int getAcknowledge() {
return this.acknowledge;
}
/**
* Sets acknowledge number.
*
* @param ack the acknowledge number to set
* @return this
*/
public TCP setAcknowledge(final int ack) {
this.acknowledge = ack;
return this;
}
/**
* Gets offset.
*
* @return the offset
*/
public byte getDataOffset() {
return this.dataOffset;
}
/**
* Sets offset.
*
* @param offset the offset to set
* @return this
*/
public TCP setDataOffset(final byte offset) {
this.dataOffset = offset;
return this;
}
/**
* Gets TCP flags.
*
* @return the TCP flags
*/
public short getFlags() {
return this.flags;
}
/**
* Sets TCP flags.
*
* @param flags the TCP flags to set
* @return this
*/
public TCP setFlags(final short flags) {
this.flags = flags;
return this;
}
/**
* Gets TCP window size.
*
* @return the TCP window size
*/
public short getWindowSize() {
return this.windowSize;
}
/**
* Sets TCP window size.
*
* @param windowSize the TCP window size to set
* @return this
*/
public TCP setWindowSize(final short windowSize) {
this.windowSize = windowSize;
return this;
}
@Override
public void resetChecksum() {
this.checksum = 0;
super.resetChecksum();
}
/**
* Gets urgent pointer.
*
* @return the urgent pointer
*/
public short getUrgentPointer() {
return this.urgentPointer;
}
/**
* Sets urgent pointer.
*
* @param urgentPointer the urgent pointer to set
* @return this
*/
public TCP setUrgentPointer(final short urgentPointer) {
this.urgentPointer = urgentPointer;
return this;
}
/**
* Gets TCP options.
*
* @return the TCP options
*/
public byte[] getOptions() {
return this.options;
}
/**
* Sets TCP options.
*
* @param options the options to set
* @return this
*/
public TCP setOptions(final byte[] options) {
this.options = options;
this.dataOffset = (byte) (20 + options.length + 3 >> 2);
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;
if (this.dataOffset == 0) {
this.dataOffset = 5; // default header length
}
length = this.dataOffset << 2;
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.putShort((short) (this.sourcePort & 0xffff));
bb.putShort((short) (this.destinationPort & 0xffff));
bb.putInt(this.sequence);
bb.putInt(this.acknowledge);
bb.putShort((short) (this.flags | this.dataOffset << 12));
bb.putShort(this.windowSize);
bb.putShort(this.checksum);
bb.putShort(this.urgentPointer);
if (this.dataOffset > 5) {
int padding;
bb.put(this.options);
padding = (this.dataOffset << 2) - 20 - this.options.length;
for (int i = 0; i < padding; i++) {
bb.put((byte) 0);
}
}
if (payloadData != null) {
bb.put(payloadData);
}
if (this.parent != null && this.parent instanceof IPv4) {
((IPv4) this.parent).setProtocol(IPv4.PROTOCOL_TCP);
}
// compute checksum if needed
if (this.checksum == 0) {
bb.rewind();
int accumulation = 0;
// compute pseudo header mac
if (this.parent != null) {
if (this.parent instanceof IPv4) {
final IPv4 ipv4 = (IPv4) this.parent;
accumulation += (ipv4.getSourceAddress() >> 16 & 0xffff)
+ (ipv4.getSourceAddress() & 0xffff);
accumulation += (ipv4.getDestinationAddress() >> 16 & 0xffff)
+ (ipv4.getDestinationAddress() & 0xffff);
accumulation += ipv4.getProtocol() & 0xff;
accumulation += length & 0xffff;
} else if (this.parent instanceof IPv6) {
final IPv6 ipv6 = (IPv6) this.parent;
final int bbLength =
Ip6Address.BYTE_LENGTH * 2 // IPv6 src, dst
+ 2 // nextHeader (with padding)
+ 4; // length
final ByteBuffer bbChecksum = ByteBuffer.allocate(bbLength);
bbChecksum.put(ipv6.getSourceAddress());
bbChecksum.put(ipv6.getDestinationAddress());
bbChecksum.put((byte) 0); // padding
bbChecksum.put(ipv6.getNextHeader());
bbChecksum.putInt(length);
bbChecksum.rewind();
for (int i = 0; i < bbLength / 2; ++i) {
accumulation += 0xffff & bbChecksum.getShort();
}
}
}
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(16, 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.sourcePort = (bb.getShort() & 0xffff);
this.destinationPort = (bb.getShort() & 0xffff);
this.sequence = bb.getInt();
this.acknowledge = bb.getInt();
this.flags = bb.getShort();
this.dataOffset = (byte) (this.flags >> 12 & 0xf);
this.flags = (short) (this.flags & 0x1ff);
this.windowSize = bb.getShort();
this.checksum = bb.getShort();
this.urgentPointer = bb.getShort();
if (this.dataOffset > 5) {
int optLength = (this.dataOffset << 2) - 20;
if (bb.limit() < bb.position() + optLength) {
optLength = bb.limit() - bb.position();
}
try {
this.options = new byte[optLength];
bb.get(this.options, 0, optLength);
} catch (final IndexOutOfBoundsException e) {
this.options = null;
}
}
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.checksum;
result = prime * result + this.destinationPort;
result = prime * result + this.sourcePort;
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 TCP)) {
return false;
}
final TCP other = (TCP) obj;
// May want to compare fields based on the flags set
return this.checksum == other.checksum
&& this.destinationPort == other.destinationPort
&& this.sourcePort == other.sourcePort
&& this.sequence == other.sequence
&& this.acknowledge == other.acknowledge
&& this.dataOffset == other.dataOffset
&& this.flags == other.flags
&& this.windowSize == other.windowSize
&& this.urgentPointer == other.urgentPointer
&& (this.dataOffset == 5 || Arrays.equals(this.options, other.options));
}
/**
* Deserializer function for TCP packets.
*
* @return deserializer function
*/
public static Deserializer<TCP> deserializer() {
return (data, offset, length) -> {
checkInput(data, offset, length, TCP_HEADER_LENGTH);
TCP tcp = new TCP();
final ByteBuffer bb = ByteBuffer.wrap(data, offset, length);
tcp.sourcePort = (bb.getShort() & 0xffff);
tcp.destinationPort = (bb.getShort() & 0xffff);
tcp.sequence = bb.getInt();
tcp.acknowledge = bb.getInt();
tcp.flags = bb.getShort();
tcp.dataOffset = (byte) (tcp.flags >> 12 & 0xf);
tcp.flags = (short) (tcp.flags & 0x1ff);
tcp.windowSize = bb.getShort();
tcp.checksum = bb.getShort();
tcp.urgentPointer = bb.getShort();
if (tcp.dataOffset > 5) {
int optLength = (tcp.dataOffset << 2) - 20;
checkHeaderLength(length, TCP_HEADER_LENGTH + tcp.dataOffset);
tcp.options = new byte[optLength];
bb.get(tcp.options, 0, optLength);
}
tcp.payload = Data.deserializer()
.deserialize(data, bb.position(), bb.limit() - bb.position());
tcp.payload.setParent(tcp);
return tcp;
};
}
@Override
public String toString() {
return toStringHelper(getClass())
.add("sourcePort", Integer.toString(sourcePort))
.add("destinationPort", Integer.toString(destinationPort))
.add("sequence", Integer.toString(sequence))
.add("acknowledge", Integer.toString(acknowledge))
.add("dataOffset", Byte.toString(dataOffset))
.add("flags", Short.toString(flags))
.add("windowSize", Short.toString(windowSize))
.add("checksum", Short.toString(checksum))
.add("urgentPointer", Short.toString(urgentPointer))
.add("options", Arrays.toString(options))
.toString();
}
}