pcap/org.eclipse.tracecompass.pcap.core/src/org/eclipse/tracecompass/internal/pcap/core/protocol/tcp/TCPPacket.java - tracecompass/org.eclipse.tracecompass - Git at Google

 /*******************************************************************************
  * Copyright (c) 2014, 2019 Ericsson
  *
  * All rights reserved. This program and the accompanying materials are
  * made available under the terms of the Eclipse Public License 2.0 which
  * accompanies this distribution, and is available at
  * https://www.eclipse.org/legal/epl-2.0/
  *
  * SPDX-License-Identifier: EPL-2.0
  *
  * Contributors:
  *   Vincent Perot - Initial API and implementation
  *******************************************************************************/

 package org.eclipse.tracecompass.internal.pcap.core.protocol.tcp;

 import java.nio.ByteBuffer;
 import java.nio.ByteOrder;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.Objects;

 import org.eclipse.jdt.annotation.NonNull;
 import org.eclipse.jdt.annotation.Nullable;
 import org.eclipse.tracecompass.common.core.NonNullUtils;
 import org.eclipse.tracecompass.internal.pcap.core.packet.BadPacketException;
 import org.eclipse.tracecompass.internal.pcap.core.packet.Packet;
 import org.eclipse.tracecompass.internal.pcap.core.protocol.PcapProtocol;
 import org.eclipse.tracecompass.internal.pcap.core.protocol.unknown.UnknownPacket;
 import org.eclipse.tracecompass.internal.pcap.core.trace.PcapFile;
 import org.eclipse.tracecompass.internal.pcap.core.util.ConversionHelper;

 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableMap.Builder;

 /**
  * Class that represents a TCP packet.
  *
  * @author Vincent Perot
  */
 public class TCPPacket extends Packet {

     private final @Nullable Packet fChildPacket;
     private final @Nullable ByteBuffer fPayload;

     private final int fSourcePort;
     private final int fDestinationPort;
     private final long fSequenceNumber;
     private final long fAcknowledgmentNumber;
     private final int fDataOffset; // in 4 bytes block
     private final byte fReservedField;
     private final boolean fNSFlag;
     private final boolean fCWRFlag;
     private final boolean fECEFlag;
     private final boolean fURGFlag;
     private final boolean fACKFlag;
     private final boolean fPSHFlag;
     private final boolean fRSTFlag;
     private final boolean fSYNFlag;
     private final boolean fFINFlag;
     private final int fWindowSize;
     private final int fChecksum;
     private final int fUrgentPointer;
     private final byte @Nullable [] fOptions; // TODO Interpret options.

     private @Nullable TCPEndpoint fSourceEndpoint;
     private @Nullable TCPEndpoint fDestinationEndpoint;

     private @Nullable Map<String, String> fFields;

     /**
      * Constructor of the TCP Packet class.
      *
      * @param file
      *            The file that contains this packet.
      * @param parent
      *            The parent packet of this packet (the encapsulating packet).
      * @param packet
      *            The entire packet (header and payload).
      * @throws BadPacketException
      *             Thrown when the packet is erroneous.
      */
     public TCPPacket(PcapFile file, @Nullable Packet parent, ByteBuffer packet) throws BadPacketException {
         super(file, parent, PcapProtocol.TCP);

         // The endpoints are lazy loaded. They are defined in the get*Endpoint()
         // methods.
         fSourceEndpoint = null;
         fDestinationEndpoint = null;

         fFields = null;

         packet.order(ByteOrder.BIG_ENDIAN);
         packet.position(0);

         fSourcePort = ConversionHelper.unsignedShortToInt(packet.getShort());
         fDestinationPort = ConversionHelper.unsignedShortToInt(packet.getShort());
         fSequenceNumber = ConversionHelper.unsignedIntToLong(packet.getInt());
         fAcknowledgmentNumber = ConversionHelper.unsignedIntToLong(packet.getInt());

         byte storage = packet.get();
         fDataOffset = ((storage & 0b11110000) >>> 4) & 0x000000FF;
         fReservedField = (byte) ((storage & 0b00001110) >>> 1);
         fNSFlag = isBitSet(storage, 0);

         storage = packet.get();
         fCWRFlag = isBitSet(storage, 7);
         fECEFlag = isBitSet(storage, 6);
         fURGFlag = isBitSet(storage, 5);
         fACKFlag = isBitSet(storage, 4);
         fPSHFlag = isBitSet(storage, 3);
         fRSTFlag = isBitSet(storage, 2);
         fSYNFlag = isBitSet(storage, 1);
         fFINFlag = isBitSet(storage, 0);

         fWindowSize = ConversionHelper.unsignedShortToInt(packet.getShort());
         fChecksum = ConversionHelper.unsignedShortToInt(packet.getShort());
         fUrgentPointer = ConversionHelper.unsignedShortToInt(packet.getShort());

         // Get options if any
         if (fDataOffset > TCPValues.DEFAULT_HEADER_LENGTH) {
             fOptions = new byte[(fDataOffset - TCPValues.DEFAULT_HEADER_LENGTH) * TCPValues.BLOCK_SIZE];
             packet.get(fOptions);
         } else {
             fOptions = null;
         }

         // Get payload if any.
         if (packet.remaining() > 0) {
             ByteBuffer payload = packet.slice();
             payload.order(ByteOrder.BIG_ENDIAN);
             fPayload = payload;
         } else {
             fPayload = null;
         }

         // find child packet
         fChildPacket = findChildPacket();

     }

     @Override
     public @Nullable Packet getChildPacket() {
         return fChildPacket;
     }

     @Override
     public @Nullable ByteBuffer getPayload() {
         return fPayload;
     }

     /**
      * {@inheritDoc}
      *
      * See http://www.iana.org/assignments/service-names-port-numbers/service-
      * names-port-numbers.xhtml or
      * http://en.wikipedia.org/wiki/List_of_TCP_and_UDP_port_numbers
      */
     @Override
     protected @Nullable Packet findChildPacket() throws BadPacketException {
         // TODO implement further protocols and update this
         ByteBuffer payload = fPayload;
         if (payload == null) {
             return null;
         }

         return new UnknownPacket(getPcapFile(), this, payload);
     }

     @Override
     public String toString() {
         final ByteBuffer payload = fPayload;
         int length = 0;
         if (payload != null) {
             length = payload.limit();
         }

         String flagString = ""; // TODO Finish it. Im just too lazy. //$NON-NLS-1$
         String string = getProtocol().getName() + ", Source Port: " + fSourcePort + ", Destination Port: " + fDestinationPort + //$NON-NLS-1$ //$NON-NLS-2$
                 "\nSequence Number: " + fSequenceNumber + ", Acknowledgment Number: " + fAcknowledgmentNumber + //$NON-NLS-1$ //$NON-NLS-2$
                 "\nHeader length: " + fDataOffset * TCPValues.BLOCK_SIZE + " bytes, Data length: " + length + //$NON-NLS-1$ //$NON-NLS-2$
                 "\n" + flagString + "Window size value: " + fWindowSize + ", Urgent Pointer: " + String.format("%s%04x", "0x", fUrgentPointer) + //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$ //$NON-NLS-4$ //$NON-NLS-5$
                 "\nChecksum: " + String.format("%s%04x", "0x", fChecksum) + "\n"; //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$ //$NON-NLS-4$
         final Packet child = fChildPacket;
         if (child != null) {
             return string + child.toString();
         }
         return string;
     }

     /**
      * Getter method that returns the TCP Source Port.
      *
      * @return The source Port.
      */
     public int getSourcePort() {
         return fSourcePort;
     }

     /**
      * Getter method that returns the TCP Destination Port.
      *
      * @return The destination Port.
      */
     public int getDestinationPort() {
         return fDestinationPort;
     }

     /**
      * Getter method that returns the Sequence Number. The sequence number has a
      * dual role:
      * <ul>
      * <li>If the SYN flag is set (1), then this is the initial sequence number.
      * The sequence number of the actual first data byte and the acknowledged
      * number in the corresponding ACK are then this sequence number plus 1.</li>
      * <li>If the SYN flag is clear (0), then this is the accumulated sequence
      * number of the first data byte of this segment for the current session.</li>
      * </ul>
      *
      * Source: http://en.wikipedia.org/wiki/Transmission_Control_Protocol
      *
      * @return The Sequence Number.
      */
     public long getSequenceNumber() {
         return fSequenceNumber;
     }

     /**
      * Getter method that returns the Acknowledgment Number.
      *
      * If the ACK flag is set then the value of this field is the next sequence
      * number that the receiver is expecting. This acknowledges receipt of all
      * prior bytes (if any). The first ACK sent by each end acknowledges the
      * other end's initial sequence number itself, but no data.
      *
      * Source: http://en.wikipedia.org/wiki/Transmission_Control_Protocol
      *
      * @return The Acknowledgment Number.
      */
     public long getAcknowledgmentNumber() {
         return fAcknowledgmentNumber;
     }

     /**
      * Getter method that returns the size of the TCP header in 4 bytes data
      * block. The minimum size is 5 words and the maximum is 15 words.
      *
      * @return The Data Offset.
      */
     public int getDataOffset() {
         return fDataOffset;
     }

     /**
      * Getter method that returns the Reserved field. This field is for future
      * use and should always be zero. In this library, it is used as a mean to
      * verify the validity of a TCP packet.
      *
      * @return The Reserved Field.
      */
     public byte getReservedField() {
         return fReservedField;
     }

     /**
      * Getter method that returns the state of the NS flag.
      *
      * @return The state of the NS flag.
      */
     public boolean isNSFlagSet() {
         return fNSFlag;
     }

     /**
      * Getter method that returns the state of the CWR flag.
      *
      * @return The state of the CWR flag.
      */
     public boolean isCongestionWindowReducedFlagSet() {
         return fCWRFlag;
     }

     /**
      * Getter method that returns the state of the ECE flag.
      *
      * @return The state of the ECE flag.
      */
     public boolean isECNEchoFlagSet() {
         return fECEFlag;
     }

     /**
      * Getter method that returns the state of the URG flag.
      *
      * @return The state of the URG flag.
      */
     public boolean isUrgentFlagSet() {
         return fURGFlag;
     }

     /**
      * Getter method that returns the state of the ACK flag.
      *
      * @return The state of the ACK flag.
      */
     public boolean isAcknowledgeFlagSet() {
         return fACKFlag;
     }

     /**
      * Getter method that returns the state of the PSH flag.
      *
      * @return The state of the PSH flag.
      */
     public boolean isPushFlagSet() {
         return fPSHFlag;
     }

     /**
      * Getter method that returns the state of the RST flag.
      *
      * @return The state of the RST flag.
      */
     public boolean isResetFlagSet() {
         return fRSTFlag;
     }

     /**
      * Getter method that returns the state of the SYN flag.
      *
      * @return The state of the SYN flag.
      */
     public boolean isSynchronizationFlagSet() {
         return fSYNFlag;
     }

     /**
      * Getter method that returns the state of the FIN flag.
      *
      * @return The state of the FIN flag.
      */
     public boolean isFinalFlagSet() {
         return fFINFlag;
     }

     /**
      * Getter method that returns the size of the windows, in windows size unit
      * (by default, bytes), that the sender of this packet is willing to
      * receive.
      *
      * @return The Window Size.
      */
     public int getWindowSize() {
         return fWindowSize;
     }

     /**
      * Getter method that returns the checksum of this packet. This checksum may
      * be wrong if the packet is erroneous.
      *
      * @return The data and header checksum.
      */
     public int getChecksum() {
         return fChecksum;
     }

     /**
      * Getter method that returns the Urgent Pointer. If the URG flag is set,
      * this field is an offset from the sequence number indicating the last
      * urgent data byte.
      *
      * @return The Urgent Pointer.
      */
     public int getUrgentPointer() {
         return fUrgentPointer;
     }

     /**
      * Getter method that returns the options. This method returns null if no
      * options are present.
      *
      * @return The options of the packet.
      */
     public byte @Nullable [] getOptions() {
         byte[] options = fOptions;
         if (options == null) {
             return null;
         }
         return Arrays.copyOf(options, options.length);
     }

     @Override
     public boolean validate() {
         // Not yet implemented. ATM, we consider that all packets are valid.
         // This is the case for all packets.
         // TODO Implement it.
         return true;
     }

     @Override
     public TCPEndpoint getSourceEndpoint() {
         @Nullable
         TCPEndpoint endpoint = fSourceEndpoint;
         if (endpoint == null) {
             endpoint = new TCPEndpoint(this, true);
         }
         fSourceEndpoint = endpoint;
         return fSourceEndpoint;
     }

     @Override
     public TCPEndpoint getDestinationEndpoint() {
         @Nullable
         TCPEndpoint endpoint = fDestinationEndpoint;

         if (endpoint == null) {
             endpoint = new TCPEndpoint(this, false);
         }
         fDestinationEndpoint = endpoint;
         return fDestinationEndpoint;
     }

     @Override
     public Map<String, String> getFields() {
         Map<String, String> map = fFields;
         if (map == null) {
             Builder<String, String> builder = ImmutableMap.<@NonNull String, @NonNull String> builder()
                     .put("Source Port", String.valueOf(fSourcePort)) //$NON-NLS-1$
                     .put("Destination Port", String.valueOf(fDestinationPort)) //$NON-NLS-1$
                     .put("Sequence Number", String.valueOf(fSequenceNumber)) //$NON-NLS-1$
                     .put("Acknowledgement Number", String.valueOf(fAcknowledgmentNumber)) //$NON-NLS-1$
                     .put("Length", String.valueOf(fDataOffset * TCPValues.BLOCK_SIZE) + " bytes") //$NON-NLS-1$ //$NON-NLS-2$
                     .put("ECN-Nonce Flag", String.valueOf(fNSFlag)) //$NON-NLS-1$
                     .put("Congestion Window Reduced Flag", String.valueOf(fCWRFlag)) //$NON-NLS-1$
                     .put("ECN-Echo Flag", String.valueOf(fECEFlag)) //$NON-NLS-1$
                     .put("Urgent Flag", String.valueOf(fURGFlag)) //$NON-NLS-1$
                     .put("ACK Flag", String.valueOf(fACKFlag)) //$NON-NLS-1$
                     .put("PSH Flag", String.valueOf(fPSHFlag)) //$NON-NLS-1$
                     .put("RST Flag", String.valueOf(fRSTFlag)) //$NON-NLS-1$
                     .put("SYN Flag", String.valueOf(fSYNFlag)) //$NON-NLS-1$
                     .put("FIN Flag", String.valueOf(fFINFlag)) //$NON-NLS-1$
                     .put("Window Size Value", String.valueOf(fWindowSize)) //$NON-NLS-1$
                     .put("Checksum", String.format("%s%04x", "0x", fChecksum)) //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
                     .put("Urgent Pointer", String.format("%s%04x", "0x", fUrgentPointer)); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
             byte[] options = fOptions;
             if (options == null) {
                 builder.put("Options", EMPTY_STRING); //$NON-NLS-1$
             } else {
                 builder.put("Options", ConversionHelper.bytesToHex(options, true)); //$NON-NLS-1$

             }
             fFields = builder.build();
             return fFields;
         }
         return map;
     }

     @Override
     public String getLocalSummaryString() {
         return "Src Port: " + fSourcePort + ", Dst Port: " + fDestinationPort + //$NON-NLS-1$ //$NON-NLS-2$
                 ", Seq: " + fSequenceNumber + ", Ack: " + fAcknowledgmentNumber + //$NON-NLS-1$ //$NON-NLS-2$
                 ", Len: " + (fDataOffset * TCPValues.BLOCK_SIZE); //$NON-NLS-1$
     }

     @Override
     protected String getSignificationString() {
         StringBuilder sb = new StringBuilder();
         sb.append(fSourcePort)
                 .append(" > ") //$NON-NLS-1$
                 .append(fDestinationPort);

         if (!(generateFlagString().equals(EMPTY_STRING))) {
             sb.append(' ')
                     .append('[')
                     .append(generateFlagString())
                     .append(']');
         }
         sb.append(" Seq=") //$NON-NLS-1$
         .append(fSequenceNumber);

         if (fACKFlag) {
             sb.append(" Ack=") //$NON-NLS-1$
             .append(fAcknowledgmentNumber);
         }

         sb.append(" Len=") //$NON-NLS-1$
         .append((fDataOffset * TCPValues.BLOCK_SIZE));

         return NonNullUtils.nullToEmptyString(sb);    }

     private String generateFlagString() {
         StringBuilder sb = new StringBuilder();
         boolean start = true;

         if (fSYNFlag) {
             if (!start) {
                 sb.append(", "); //$NON-NLS-1$
             }
             sb.append("SYN"); //$NON-NLS-1$
             start = false;
         }
         if (fACKFlag) {
             if (!start) {
                 sb.append(", "); //$NON-NLS-1$
             }
             sb.append("ACK"); //$NON-NLS-1$
             start = false;
         }
         if (fFINFlag) {
             if (!start) {
                 sb.append(", "); //$NON-NLS-1$
             }
             sb.append("FIN"); //$NON-NLS-1$
             start = false;
         }
         if (fRSTFlag) {
             if (!start) {
                 sb.append(", "); //$NON-NLS-1$
             }
             sb.append("RST"); //$NON-NLS-1$
             start = false;
         }
         if (fPSHFlag) {
             if (!start) {
                 sb.append(", "); //$NON-NLS-1$
             }
             sb.append("PSH"); //$NON-NLS-1$
             start = false;
         }
         if (fURGFlag) {
             if (!start) {
                 sb.append(", "); //$NON-NLS-1$
             }
             sb.append("URG"); //$NON-NLS-1$
             start = false;
         }
         if (fNSFlag) {
             if (!start) {
                 sb.append(", "); //$NON-NLS-1$
             }
             sb.append("NS"); //$NON-NLS-1$
             start = false;
         }
         if (fCWRFlag) {
             if (!start) {
                 sb.append(", "); //$NON-NLS-1$
             }
             sb.append("CWR"); //$NON-NLS-1$
             start = false;
         }
         if (fECEFlag) {
             if (!start) {
                 sb.append(", "); //$NON-NLS-1$
             }
             sb.append("ECE"); //$NON-NLS-1$
             start = false;
         }
         return NonNullUtils.nullToEmptyString(sb);
     }

     @Override
     public int hashCode() {
         final int prime = 31;
         int result = 1;
         result = prime * result + (fACKFlag ? 1231 : 1237);
         result = prime * result + (int) (fAcknowledgmentNumber ^ (fAcknowledgmentNumber >>> 32));
         result = prime * result + (fCWRFlag ? 1231 : 1237);
         result = prime * result + fChecksum;
         final Packet child = fChildPacket;
         if (child != null) {
             result = prime * result + child.hashCode();
         } else {
             result = prime * result;
         }
         result = prime * result + fDataOffset;
         result = prime * result + fDestinationPort;
         result = prime * result + (fECEFlag ? 1231 : 1237);
         result = prime * result + (fFINFlag ? 1231 : 1237);
         result = prime * result + (fNSFlag ? 1231 : 1237);
         result = prime * result + Arrays.hashCode(fOptions);
         result = prime * result + (fPSHFlag ? 1231 : 1237);
         if (child == null) {
             result = prime * result + payloadHashCode(fPayload);
         }
         result = prime * result + (fRSTFlag ? 1231 : 1237);
         result = prime * result + fReservedField;
         result = prime * result + (fSYNFlag ? 1231 : 1237);
         result = prime * result + (int) (fSequenceNumber ^ (fSequenceNumber >>> 32));
         result = prime * result + fSourcePort;
         result = prime * result + (fURGFlag ? 1231 : 1237);
         result = prime * result + fUrgentPointer;
         result = prime * result + fWindowSize;
         return result;
     }

     @Override
     public boolean equals(@Nullable Object obj) {
         if (this == obj) {
             return true;
         }
         if (obj == null) {
             return false;
         }
         if (getClass() != obj.getClass()) {
             return false;
         }
         TCPPacket other = (TCPPacket) obj;
         if (fACKFlag != other.fACKFlag) {
             return false;
         }
         if (fAcknowledgmentNumber != other.fAcknowledgmentNumber) {
             return false;
         }
         if (fCWRFlag != other.fCWRFlag) {
             return false;
         }
         if (fChecksum != other.fChecksum) {
             return false;
         }
         if(!Objects.equals(fChildPacket, other.fChildPacket)){
             return false;
         }
         if (fDataOffset != other.fDataOffset) {
             return false;
         }
         if (fDestinationPort != other.fDestinationPort) {
             return false;
         }
         if (fECEFlag != other.fECEFlag) {
             return false;
         }
         if (fFINFlag != other.fFINFlag) {
             return false;
         }
         if (fNSFlag != other.fNSFlag) {
             return false;
         }
         if (!Arrays.equals(fOptions, other.fOptions)) {
             return false;
         }
         if (fPSHFlag != other.fPSHFlag) {
             return false;
         }
         if (fChildPacket == null && !payloadEquals(fPayload, other.fPayload)) {
             return false;
         }
         if (fRSTFlag != other.fRSTFlag) {
             return false;
         }
         if (fReservedField != other.fReservedField) {
             return false;
         }
         if (fSYNFlag != other.fSYNFlag) {
             return false;
         }
         if (fSequenceNumber != other.fSequenceNumber) {
             return false;
         }
         if (fSourcePort != other.fSourcePort) {
             return false;
         }
         if (fURGFlag != other.fURGFlag) {
             return false;
         }
         if (fUrgentPointer != other.fUrgentPointer) {
             return false;
         }
         return (fWindowSize == other.fWindowSize) ;
     }

 }
	/*******************************************************************************
	* Copyright (c) 2014, 2019 Ericsson
	*
	* All rights reserved. This program and the accompanying materials are
	* made available under the terms of the Eclipse Public License 2.0 which
	* accompanies this distribution, and is available at
	* https://www.eclipse.org/legal/epl-2.0/
	*
	* SPDX-License-Identifier: EPL-2.0
	*
	* Contributors:
	* Vincent Perot - Initial API and implementation
	*******************************************************************************/

	package org.eclipse.tracecompass.internal.pcap.core.protocol.tcp;

	import java.nio.ByteBuffer;
	import java.nio.ByteOrder;
	import java.util.Arrays;
	import java.util.Map;
	import java.util.Objects;

	import org.eclipse.jdt.annotation.NonNull;
	import org.eclipse.jdt.annotation.Nullable;
	import org.eclipse.tracecompass.common.core.NonNullUtils;
	import org.eclipse.tracecompass.internal.pcap.core.packet.BadPacketException;
	import org.eclipse.tracecompass.internal.pcap.core.packet.Packet;
	import org.eclipse.tracecompass.internal.pcap.core.protocol.PcapProtocol;
	import org.eclipse.tracecompass.internal.pcap.core.protocol.unknown.UnknownPacket;
	import org.eclipse.tracecompass.internal.pcap.core.trace.PcapFile;
	import org.eclipse.tracecompass.internal.pcap.core.util.ConversionHelper;

	import com.google.common.collect.ImmutableMap;
	import com.google.common.collect.ImmutableMap.Builder;

	/**
	* Class that represents a TCP packet.
	*
	* @author Vincent Perot
	*/
	public class TCPPacket extends Packet {

	private final @Nullable Packet fChildPacket;
	private final @Nullable ByteBuffer fPayload;

	private final int fSourcePort;
	private final int fDestinationPort;
	private final long fSequenceNumber;
	private final long fAcknowledgmentNumber;
	private final int fDataOffset; // in 4 bytes block
	private final byte fReservedField;
	private final boolean fNSFlag;
	private final boolean fCWRFlag;
	private final boolean fECEFlag;
	private final boolean fURGFlag;
	private final boolean fACKFlag;
	private final boolean fPSHFlag;
	private final boolean fRSTFlag;
	private final boolean fSYNFlag;
	private final boolean fFINFlag;
	private final int fWindowSize;
	private final int fChecksum;
	private final int fUrgentPointer;
	private final byte @Nullable [] fOptions; // TODO Interpret options.

	private @Nullable TCPEndpoint fSourceEndpoint;
	private @Nullable TCPEndpoint fDestinationEndpoint;

	private @Nullable Map<String, String> fFields;

	/**
	* Constructor of the TCP Packet class.
	*
	* @param file
	* The file that contains this packet.
	* @param parent
	* The parent packet of this packet (the encapsulating packet).
	* @param packet
	* The entire packet (header and payload).
	* @throws BadPacketException
	* Thrown when the packet is erroneous.
	*/
	public TCPPacket(PcapFile file, @Nullable Packet parent, ByteBuffer packet) throws BadPacketException {
	super(file, parent, PcapProtocol.TCP);

	// The endpoints are lazy loaded. They are defined in the get*Endpoint()
	// methods.
	fSourceEndpoint = null;
	fDestinationEndpoint = null;

	fFields = null;

	packet.order(ByteOrder.BIG_ENDIAN);
	packet.position(0);

	fSourcePort = ConversionHelper.unsignedShortToInt(packet.getShort());
	fDestinationPort = ConversionHelper.unsignedShortToInt(packet.getShort());
	fSequenceNumber = ConversionHelper.unsignedIntToLong(packet.getInt());
	fAcknowledgmentNumber = ConversionHelper.unsignedIntToLong(packet.getInt());

	byte storage = packet.get();
	fDataOffset = ((storage & 0b11110000) >>> 4) & 0x000000FF;
	fReservedField = (byte) ((storage & 0b00001110) >>> 1);
	fNSFlag = isBitSet(storage, 0);

	storage = packet.get();
	fCWRFlag = isBitSet(storage, 7);
	fECEFlag = isBitSet(storage, 6);
	fURGFlag = isBitSet(storage, 5);
	fACKFlag = isBitSet(storage, 4);
	fPSHFlag = isBitSet(storage, 3);
	fRSTFlag = isBitSet(storage, 2);
	fSYNFlag = isBitSet(storage, 1);
	fFINFlag = isBitSet(storage, 0);

	fWindowSize = ConversionHelper.unsignedShortToInt(packet.getShort());
	fChecksum = ConversionHelper.unsignedShortToInt(packet.getShort());
	fUrgentPointer = ConversionHelper.unsignedShortToInt(packet.getShort());

	// Get options if any
	if (fDataOffset > TCPValues.DEFAULT_HEADER_LENGTH) {
	fOptions = new byte[(fDataOffset - TCPValues.DEFAULT_HEADER_LENGTH) * TCPValues.BLOCK_SIZE];
	packet.get(fOptions);
	} else {
	fOptions = null;
	}

	// Get payload if any.
	if (packet.remaining() > 0) {
	ByteBuffer payload = packet.slice();
	payload.order(ByteOrder.BIG_ENDIAN);
	fPayload = payload;
	} else {
	fPayload = null;
	}

	// find child packet
	fChildPacket = findChildPacket();

	}

	@Override
	public @Nullable Packet getChildPacket() {
	return fChildPacket;
	}

	@Override
	public @Nullable ByteBuffer getPayload() {
	return fPayload;
	}

	/**
	* {@inheritDoc}
	*
	* See http://www.iana.org/assignments/service-names-port-numbers/service-
	* names-port-numbers.xhtml or
	* http://en.wikipedia.org/wiki/List_of_TCP_and_UDP_port_numbers
	*/
	@Override
	protected @Nullable Packet findChildPacket() throws BadPacketException {
	// TODO implement further protocols and update this
	ByteBuffer payload = fPayload;
	if (payload == null) {
	return null;
	}

	return new UnknownPacket(getPcapFile(), this, payload);
	}

	@Override
	public String toString() {
	final ByteBuffer payload = fPayload;
	int length = 0;
	if (payload != null) {
	length = payload.limit();
	}

	String flagString = ""; // TODO Finish it. Im just too lazy. //$NON-NLS-1$
	String string = getProtocol().getName() + ", Source Port: " + fSourcePort + ", Destination Port: " + fDestinationPort + //$NON-NLS-1$ //$NON-NLS-2$
	"\nSequence Number: " + fSequenceNumber + ", Acknowledgment Number: " + fAcknowledgmentNumber + //$NON-NLS-1$ //$NON-NLS-2$
	"\nHeader length: " + fDataOffset * TCPValues.BLOCK_SIZE + " bytes, Data length: " + length + //$NON-NLS-1$ //$NON-NLS-2$
	"\n" + flagString + "Window size value: " + fWindowSize + ", Urgent Pointer: " + String.format("%s%04x", "0x", fUrgentPointer) + //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$ //$NON-NLS-4$ //$NON-NLS-5$
	"\nChecksum: " + String.format("%s%04x", "0x", fChecksum) + "\n"; //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$ //$NON-NLS-4$
	final Packet child = fChildPacket;
	if (child != null) {
	return string + child.toString();
	}
	return string;
	}

	/**
	* Getter method that returns the TCP Source Port.
	*
	* @return The source Port.
	*/
	public int getSourcePort() {
	return fSourcePort;
	}

	/**
	* Getter method that returns the TCP Destination Port.
	*
	* @return The destination Port.
	*/
	public int getDestinationPort() {
	return fDestinationPort;
	}

	/**
	* Getter method that returns the Sequence Number. The sequence number has a
	* dual role:
	* <ul>
	* <li>If the SYN flag is set (1), then this is the initial sequence number.
	* The sequence number of the actual first data byte and the acknowledged
	* number in the corresponding ACK are then this sequence number plus 1.</li>
	* <li>If the SYN flag is clear (0), then this is the accumulated sequence
	* number of the first data byte of this segment for the current session.</li>
	* </ul>
	*
	* Source: http://en.wikipedia.org/wiki/Transmission_Control_Protocol
	*
	* @return The Sequence Number.
	*/
	public long getSequenceNumber() {
	return fSequenceNumber;
	}

	/**
	* Getter method that returns the Acknowledgment Number.
	*
	* If the ACK flag is set then the value of this field is the next sequence
	* number that the receiver is expecting. This acknowledges receipt of all
	* prior bytes (if any). The first ACK sent by each end acknowledges the
	* other end's initial sequence number itself, but no data.
	*
	* Source: http://en.wikipedia.org/wiki/Transmission_Control_Protocol
	*
	* @return The Acknowledgment Number.
	*/
	public long getAcknowledgmentNumber() {
	return fAcknowledgmentNumber;
	}

	/**
	* Getter method that returns the size of the TCP header in 4 bytes data
	* block. The minimum size is 5 words and the maximum is 15 words.
	*
	* @return The Data Offset.
	*/
	public int getDataOffset() {
	return fDataOffset;
	}

	/**
	* Getter method that returns the Reserved field. This field is for future
	* use and should always be zero. In this library, it is used as a mean to
	* verify the validity of a TCP packet.
	*
	* @return The Reserved Field.
	*/
	public byte getReservedField() {
	return fReservedField;
	}

	/**
	* Getter method that returns the state of the NS flag.
	*
	* @return The state of the NS flag.
	*/
	public boolean isNSFlagSet() {
	return fNSFlag;
	}

	/**
	* Getter method that returns the state of the CWR flag.
	*
	* @return The state of the CWR flag.
	*/
	public boolean isCongestionWindowReducedFlagSet() {
	return fCWRFlag;
	}

	/**
	* Getter method that returns the state of the ECE flag.
	*
	* @return The state of the ECE flag.
	*/
	public boolean isECNEchoFlagSet() {
	return fECEFlag;
	}

	/**
	* Getter method that returns the state of the URG flag.
	*
	* @return The state of the URG flag.
	*/
	public boolean isUrgentFlagSet() {
	return fURGFlag;
	}

	/**
	* Getter method that returns the state of the ACK flag.
	*
	* @return The state of the ACK flag.
	*/
	public boolean isAcknowledgeFlagSet() {
	return fACKFlag;
	}

	/**
	* Getter method that returns the state of the PSH flag.
	*
	* @return The state of the PSH flag.
	*/
	public boolean isPushFlagSet() {
	return fPSHFlag;
	}

	/**
	* Getter method that returns the state of the RST flag.
	*
	* @return The state of the RST flag.
	*/
	public boolean isResetFlagSet() {
	return fRSTFlag;
	}

	/**
	* Getter method that returns the state of the SYN flag.
	*
	* @return The state of the SYN flag.
	*/
	public boolean isSynchronizationFlagSet() {
	return fSYNFlag;
	}

	/**
	* Getter method that returns the state of the FIN flag.
	*
	* @return The state of the FIN flag.
	*/
	public boolean isFinalFlagSet() {
	return fFINFlag;
	}

	/**
	* Getter method that returns the size of the windows, in windows size unit
	* (by default, bytes), that the sender of this packet is willing to
	* receive.
	*
	* @return The Window Size.
	*/
	public int getWindowSize() {
	return fWindowSize;
	}

	/**
	* Getter method that returns the checksum of this packet. This checksum may
	* be wrong if the packet is erroneous.
	*
	* @return The data and header checksum.
	*/
	public int getChecksum() {
	return fChecksum;
	}

	/**
	* Getter method that returns the Urgent Pointer. If the URG flag is set,
	* this field is an offset from the sequence number indicating the last
	* urgent data byte.
	*
	* @return The Urgent Pointer.
	*/
	public int getUrgentPointer() {
	return fUrgentPointer;
	}

	/**
	* Getter method that returns the options. This method returns null if no
	* options are present.
	*
	* @return The options of the packet.
	*/
	public byte @Nullable [] getOptions() {
	byte[] options = fOptions;
	if (options == null) {
	return null;
	}
	return Arrays.copyOf(options, options.length);
	}

	@Override
	public boolean validate() {
	// Not yet implemented. ATM, we consider that all packets are valid.
	// This is the case for all packets.
	// TODO Implement it.
	return true;
	}

	@Override
	public TCPEndpoint getSourceEndpoint() {
	@Nullable
	TCPEndpoint endpoint = fSourceEndpoint;
	if (endpoint == null) {
	endpoint = new TCPEndpoint(this, true);
	}
	fSourceEndpoint = endpoint;
	return fSourceEndpoint;
	}

	@Override
	public TCPEndpoint getDestinationEndpoint() {
	@Nullable
	TCPEndpoint endpoint = fDestinationEndpoint;

	if (endpoint == null) {
	endpoint = new TCPEndpoint(this, false);
	}
	fDestinationEndpoint = endpoint;
	return fDestinationEndpoint;
	}

	@Override
	public Map<String, String> getFields() {
	Map<String, String> map = fFields;
	if (map == null) {
	Builder<String, String> builder = ImmutableMap.<@NonNull String, @NonNull String> builder()
	.put("Source Port", String.valueOf(fSourcePort)) //$NON-NLS-1$
	.put("Destination Port", String.valueOf(fDestinationPort)) //$NON-NLS-1$
	.put("Sequence Number", String.valueOf(fSequenceNumber)) //$NON-NLS-1$
	.put("Acknowledgement Number", String.valueOf(fAcknowledgmentNumber)) //$NON-NLS-1$
	.put("Length", String.valueOf(fDataOffset * TCPValues.BLOCK_SIZE) + " bytes") //$NON-NLS-1$ //$NON-NLS-2$
	.put("ECN-Nonce Flag", String.valueOf(fNSFlag)) //$NON-NLS-1$
	.put("Congestion Window Reduced Flag", String.valueOf(fCWRFlag)) //$NON-NLS-1$
	.put("ECN-Echo Flag", String.valueOf(fECEFlag)) //$NON-NLS-1$
	.put("Urgent Flag", String.valueOf(fURGFlag)) //$NON-NLS-1$
	.put("ACK Flag", String.valueOf(fACKFlag)) //$NON-NLS-1$
	.put("PSH Flag", String.valueOf(fPSHFlag)) //$NON-NLS-1$
	.put("RST Flag", String.valueOf(fRSTFlag)) //$NON-NLS-1$
	.put("SYN Flag", String.valueOf(fSYNFlag)) //$NON-NLS-1$
	.put("FIN Flag", String.valueOf(fFINFlag)) //$NON-NLS-1$
	.put("Window Size Value", String.valueOf(fWindowSize)) //$NON-NLS-1$
	.put("Checksum", String.format("%s%04x", "0x", fChecksum)) //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
	.put("Urgent Pointer", String.format("%s%04x", "0x", fUrgentPointer)); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
	byte[] options = fOptions;
	if (options == null) {
	builder.put("Options", EMPTY_STRING); //$NON-NLS-1$
	} else {
	builder.put("Options", ConversionHelper.bytesToHex(options, true)); //$NON-NLS-1$

	}
	fFields = builder.build();
	return fFields;
	}
	return map;
	}

	@Override
	public String getLocalSummaryString() {
	return "Src Port: " + fSourcePort + ", Dst Port: " + fDestinationPort + //$NON-NLS-1$ //$NON-NLS-2$
	", Seq: " + fSequenceNumber + ", Ack: " + fAcknowledgmentNumber + //$NON-NLS-1$ //$NON-NLS-2$
	", Len: " + (fDataOffset * TCPValues.BLOCK_SIZE); //$NON-NLS-1$
	}

	@Override
	protected String getSignificationString() {
	StringBuilder sb = new StringBuilder();
	sb.append(fSourcePort)
	.append(" > ") //$NON-NLS-1$
	.append(fDestinationPort);

	if (!(generateFlagString().equals(EMPTY_STRING))) {
	sb.append(' ')
	.append('[')
	.append(generateFlagString())
	.append(']');
	}
	sb.append(" Seq=") //$NON-NLS-1$
	.append(fSequenceNumber);

	if (fACKFlag) {
	sb.append(" Ack=") //$NON-NLS-1$
	.append(fAcknowledgmentNumber);
	}

	sb.append(" Len=") //$NON-NLS-1$
	.append((fDataOffset * TCPValues.BLOCK_SIZE));

	return NonNullUtils.nullToEmptyString(sb); }

	private String generateFlagString() {
	StringBuilder sb = new StringBuilder();
	boolean start = true;

	if (fSYNFlag) {
	if (!start) {
	sb.append(", "); //$NON-NLS-1$
	}
	sb.append("SYN"); //$NON-NLS-1$
	start = false;
	}
	if (fACKFlag) {
	if (!start) {
	sb.append(", "); //$NON-NLS-1$
	}
	sb.append("ACK"); //$NON-NLS-1$
	start = false;
	}
	if (fFINFlag) {
	if (!start) {
	sb.append(", "); //$NON-NLS-1$
	}
	sb.append("FIN"); //$NON-NLS-1$
	start = false;
	}
	if (fRSTFlag) {
	if (!start) {
	sb.append(", "); //$NON-NLS-1$
	}
	sb.append("RST"); //$NON-NLS-1$
	start = false;
	}
	if (fPSHFlag) {
	if (!start) {
	sb.append(", "); //$NON-NLS-1$
	}
	sb.append("PSH"); //$NON-NLS-1$
	start = false;
	}
	if (fURGFlag) {
	if (!start) {
	sb.append(", "); //$NON-NLS-1$
	}
	sb.append("URG"); //$NON-NLS-1$
	start = false;
	}
	if (fNSFlag) {
	if (!start) {
	sb.append(", "); //$NON-NLS-1$
	}
	sb.append("NS"); //$NON-NLS-1$
	start = false;
	}
	if (fCWRFlag) {
	if (!start) {
	sb.append(", "); //$NON-NLS-1$
	}
	sb.append("CWR"); //$NON-NLS-1$
	start = false;
	}
	if (fECEFlag) {
	if (!start) {
	sb.append(", "); //$NON-NLS-1$
	}
	sb.append("ECE"); //$NON-NLS-1$
	start = false;
	}
	return NonNullUtils.nullToEmptyString(sb);
	}

	@Override
	public int hashCode() {
	final int prime = 31;
	int result = 1;
	result = prime * result + (fACKFlag ? 1231 : 1237);
	result = prime * result + (int) (fAcknowledgmentNumber ^ (fAcknowledgmentNumber >>> 32));
	result = prime * result + (fCWRFlag ? 1231 : 1237);
	result = prime * result + fChecksum;
	final Packet child = fChildPacket;
	if (child != null) {
	result = prime * result + child.hashCode();
	} else {
	result = prime * result;
	}
	result = prime * result + fDataOffset;
	result = prime * result + fDestinationPort;
	result = prime * result + (fECEFlag ? 1231 : 1237);
	result = prime * result + (fFINFlag ? 1231 : 1237);
	result = prime * result + (fNSFlag ? 1231 : 1237);
	result = prime * result + Arrays.hashCode(fOptions);
	result = prime * result + (fPSHFlag ? 1231 : 1237);
	if (child == null) {
	result = prime * result + payloadHashCode(fPayload);
	}
	result = prime * result + (fRSTFlag ? 1231 : 1237);
	result = prime * result + fReservedField;
	result = prime * result + (fSYNFlag ? 1231 : 1237);
	result = prime * result + (int) (fSequenceNumber ^ (fSequenceNumber >>> 32));
	result = prime * result + fSourcePort;
	result = prime * result + (fURGFlag ? 1231 : 1237);
	result = prime * result + fUrgentPointer;
	result = prime * result + fWindowSize;
	return result;
	}

	@Override
	public boolean equals(@Nullable Object obj) {
	if (this == obj) {
	return true;
	}
	if (obj == null) {
	return false;
	}
	if (getClass() != obj.getClass()) {
	return false;
	}
	TCPPacket other = (TCPPacket) obj;
	if (fACKFlag != other.fACKFlag) {
	return false;
	}
	if (fAcknowledgmentNumber != other.fAcknowledgmentNumber) {
	return false;
	}
	if (fCWRFlag != other.fCWRFlag) {
	return false;
	}
	if (fChecksum != other.fChecksum) {
	return false;
	}
	if(!Objects.equals(fChildPacket, other.fChildPacket)){
	return false;
	}
	if (fDataOffset != other.fDataOffset) {
	return false;
	}
	if (fDestinationPort != other.fDestinationPort) {
	return false;
	}
	if (fECEFlag != other.fECEFlag) {
	return false;
	}
	if (fFINFlag != other.fFINFlag) {
	return false;
	}
	if (fNSFlag != other.fNSFlag) {
	return false;
	}
	if (!Arrays.equals(fOptions, other.fOptions)) {
	return false;
	}
	if (fPSHFlag != other.fPSHFlag) {
	return false;
	}
	if (fChildPacket == null && !payloadEquals(fPayload, other.fPayload)) {
	return false;
	}
	if (fRSTFlag != other.fRSTFlag) {
	return false;
	}
	if (fReservedField != other.fReservedField) {
	return false;
	}
	if (fSYNFlag != other.fSYNFlag) {
	return false;
	}
	if (fSequenceNumber != other.fSequenceNumber) {
	return false;
	}
	if (fSourcePort != other.fSourcePort) {
	return false;
	}
	if (fURGFlag != other.fURGFlag) {
	return false;
	}
	if (fUrgentPointer != other.fUrgentPointer) {
	return false;
	}
	return (fWindowSize == other.fWindowSize) ;
	}

	}