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The core module of Pcap4J.
/*_##########################################################################
_##
_## Copyright (C) 2011-2017 Pcap4J.org
_##
_##########################################################################
*/
package org.pcap4j.packet;
import static org.pcap4j.util.ByteArrays.*;
import java.io.Serializable;
import java.net.Inet4Address;
import java.net.Inet6Address;
import java.net.InetAddress;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import org.pcap4j.packet.factory.PacketFactories;
import org.pcap4j.packet.factory.PacketFactory;
import org.pcap4j.packet.namednumber.IpNumber;
import org.pcap4j.packet.namednumber.TcpOptionKind;
import org.pcap4j.packet.namednumber.TcpPort;
import org.pcap4j.util.ByteArrays;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* @author Kaito Yamada
* @since pcap4j 0.9.12
*/
public final class TcpPacket extends AbstractPacket {
// http://tools.ietf.org/html/rfc793
/**
*
*/
private static final long serialVersionUID = 7904566782140471299L;
private final TcpHeader header;
private final Packet payload;
/**
* A static factory method.
* This method validates the arguments by {@link ByteArrays#validateBounds(byte[], int, int)},
* which may throw exceptions undocumented here.
*
* @param rawData rawData
* @param offset offset
* @param length length
* @return a new TcpPacket object.
* @throws IllegalRawDataException if parsing the raw data fails.
*/
public static TcpPacket newPacket(
byte[] rawData, int offset, int length
) throws IllegalRawDataException {
ByteArrays.validateBounds(rawData, offset, length);
return new TcpPacket(rawData, offset, length);
}
private TcpPacket(byte[] rawData, int offset, int length) throws IllegalRawDataException {
this.header = new TcpHeader(rawData, offset, length);
int payloadLength = length - header.length();
if (payloadLength > 0) {
PacketFactory factory
= PacketFactories.getFactory(Packet.class, TcpPort.class);
Class class4UnknownPort = factory.getTargetClass();
Class class4DstPort = factory.getTargetClass(header.getDstPort());
TcpPort serverPort;
if (class4DstPort.equals(class4UnknownPort)) {
serverPort = header.getSrcPort();
}
else {
serverPort = header.getDstPort();
}
this.payload
= PacketFactories.getFactory(Packet.class, TcpPort.class)
.newInstance(rawData, offset + header.length(), payloadLength, serverPort);
}
else {
this.payload = null;
}
}
private TcpPacket(Builder builder) {
if (
builder == null
|| builder.srcPort == null
|| builder.dstPort == null
) {
StringBuilder sb = new StringBuilder();
sb.append("builder: ").append(builder)
.append(" builder.srcPort: ").append(builder.srcPort)
.append(" builder.dstPort: ").append(builder.dstPort);
throw new NullPointerException(sb.toString());
}
if (builder.correctChecksumAtBuild) {
if (builder.srcAddr == null || builder.dstAddr == null) {
StringBuilder sb = new StringBuilder();
sb.append("builder.srcAddr: ").append(builder.srcAddr)
.append(" builder.dstAddr: ").append(builder.dstAddr);
throw new NullPointerException(sb.toString());
}
if (!builder.srcAddr.getClass().isInstance(builder.dstAddr)) {
StringBuilder sb = new StringBuilder();
sb.append("builder.srcAddr: ").append(builder.srcAddr)
.append(" builder.dstAddr: ").append(builder.dstAddr);
throw new IllegalArgumentException(sb.toString());
}
}
this.payload = builder.payloadBuilder != null ? builder.payloadBuilder.build() : null;
this.header = new TcpHeader(
builder,
payload != null ? payload.getRawData() : new byte[0]
);
}
@Override
public TcpHeader getHeader() {
return header;
}
@Override
public Packet getPayload() {
return payload;
}
/**
*
* checksum verification is necessary for IPv6(i.e. acceptZero must be false)
*
* @param srcAddr srcAddr
* @param dstAddr dstAddr
* @param acceptZero acceptZero
* @return true if the packet represented by this object has a valid checksum;
* false otherwise.
*/
public boolean hasValidChecksum(
InetAddress srcAddr, InetAddress dstAddr, boolean acceptZero
) {
if (srcAddr == null || dstAddr == null) {
StringBuilder sb = new StringBuilder();
sb.append("srcAddr: ").append(srcAddr)
.append(" dstAddr: ").append(dstAddr);
throw new NullPointerException(sb.toString());
}
if (!srcAddr.getClass().isInstance(dstAddr)) {
StringBuilder sb = new StringBuilder();
sb.append("srcAddr: ").append(srcAddr)
.append(" dstAddr: ").append(dstAddr);
throw new IllegalArgumentException(sb.toString());
}
byte[] payloadData = payload != null ? payload.getRawData() : new byte[0];
short calculatedChecksum
= header.calcChecksum(srcAddr, dstAddr, header.getRawData(), payloadData);
if (calculatedChecksum == 0) {
return true;
}
if (header.checksum == 0 && acceptZero) {
return true;
}
return false;
}
@Override
public Builder getBuilder() {
return new Builder(this);
}
/**
* @author Kaito Yamada
* @since pcap4j 0.9.12
*/
public static final
class Builder extends AbstractBuilder
implements LengthBuilder, ChecksumBuilder {
private TcpPort srcPort;
private TcpPort dstPort;
private int sequenceNumber;
private int acknowledgmentNumber;
private byte dataOffset;
private byte reserved;
private boolean urg;
private boolean ack;
private boolean psh;
private boolean rst;
private boolean syn;
private boolean fin;
private short window;
private short checksum;
private short urgentPointer;
private List options;
private byte[] padding;
private Packet.Builder payloadBuilder;
private InetAddress srcAddr;
private InetAddress dstAddr;
private boolean correctLengthAtBuild;
private boolean correctChecksumAtBuild;
private boolean paddingAtBuild;
/**
*
*/
public Builder() {}
/**
*
* @param packet packet
*/
public Builder(TcpPacket packet) {
this.srcPort = packet.header.srcPort;
this.dstPort = packet.header.dstPort;
this.sequenceNumber = packet.header.sequenceNumber;
this.acknowledgmentNumber = packet.header.acknowledgmentNumber;
this.dataOffset = packet.header.dataOffset;
this.reserved = packet.header.reserved;
this.urg = packet.header.urg;
this.ack = packet.header.ack;
this.psh = packet.header.psh;
this.rst = packet.header.rst;
this.syn = packet.header.syn;
this.fin = packet.header.fin;
this.window = packet.header.window;
this.checksum = packet.header.checksum;
this.urgentPointer = packet.header.urgentPointer;
this.options = packet.header.options;
this.padding = packet.header.padding;
this.payloadBuilder = packet.payload != null ? packet.payload.getBuilder() : null;
}
/**
*
* @param srcPort srcPort
* @return this Builder object for method chaining.
*/
public Builder srcPort(TcpPort srcPort) {
this.srcPort = srcPort;
return this;
}
/**
*
* @param dstPort dstPort
* @return this Builder object for method chaining.
*/
public Builder dstPort(TcpPort dstPort) {
this.dstPort = dstPort;
return this;
}
/**
*
* @param sequenceNumber sequenceNumber
* @return this Builder object for method chaining.
*/
public Builder sequenceNumber(int sequenceNumber) {
this.sequenceNumber = sequenceNumber;
return this;
}
/**
*
* @param acknowledgmentNumber acknowledgmentNumber
* @return this Builder object for method chaining.
*/
public Builder acknowledgmentNumber(int acknowledgmentNumber) {
this.acknowledgmentNumber = acknowledgmentNumber;
return this;
}
/**
*
* @param dataOffset dataOffset
* @return this Builder object for method chaining.
*/
public Builder dataOffset(byte dataOffset) {
this.dataOffset = dataOffset;
return this;
}
/**
*
* @param reserved reserved
* @return this Builder object for method chaining.
*/
public Builder reserved(byte reserved) {
this.reserved = reserved;
return this;
}
/**
*
* @param urg urg
* @return this Builder object for method chaining.
*/
public Builder urg(boolean urg) {
this.urg = urg;
return this;
}
/**
*
* @param ack ack
* @return this Builder object for method chaining.
*/
public Builder ack(boolean ack) {
this.ack = ack;
return this;
}
/**
*
* @param psh psh
* @return this Builder object for method chaining.
*/
public Builder psh(boolean psh) {
this.psh = psh;
return this;
}
/**
*
* @param rst rst
* @return this Builder object for method chaining.
*/
public Builder rst(boolean rst) {
this.rst = rst;
return this;
}
/**
*
* @param syn syn
* @return this Builder object for method chaining.
*/
public Builder syn(boolean syn) {
this.syn = syn;
return this;
}
/**
*
* @param fin fin
* @return this Builder object for method chaining.
*/
public Builder fin(boolean fin) {
this.fin = fin;
return this;
}
/**
*
* @param window window
* @return this Builder object for method chaining.
*/
public Builder window(short window) {
this.window = window;
return this;
}
/**
*
* @param checksum checksum
* @return this Builder object for method chaining.
*/
public Builder checksum(short checksum) {
this.checksum = checksum;
return this;
}
/**
*
* @param urgentPointer urgentPointer
* @return this Builder object for method chaining.
*/
public Builder urgentPointer(short urgentPointer) {
this.urgentPointer = urgentPointer;
return this;
}
/**
*
* @param options options
* @return this Builder object for method chaining.
*/
public Builder options(List options) {
this.options = options;
return this;
}
/**
*
* @param padding padding
* @return this Builder object for method chaining.
*/
public Builder padding(byte[] padding) {
this.padding = padding;
return this;
}
@Override
public Builder payloadBuilder(Packet.Builder payloadBuilder) {
this.payloadBuilder = payloadBuilder;
return this;
}
@Override
public Packet.Builder getPayloadBuilder() {
return payloadBuilder;
}
/**
*
* used for checksum calculation.
*
* @param srcAddr srcAddr
* @return this Builder object for method chaining.
*/
public Builder srcAddr(InetAddress srcAddr) {
this.srcAddr = srcAddr;
return this;
}
/**
*
* used for checksum calculation
* If the lower-layer packet is a IPv6 packet and
* the extension headers including a routing header,
* this parameter is that of the final destination.
* (i.e. the last element of the Routing header)
*
* @param dstAddr dstAddr
* @return this Builder object for method chaining.
*/
public Builder dstAddr(InetAddress dstAddr) {
this.dstAddr = dstAddr;
return this;
}
@Override
public Builder correctLengthAtBuild(boolean correctLengthAtBuild) {
this.correctLengthAtBuild = correctLengthAtBuild;
return this;
}
@Override
public Builder correctChecksumAtBuild(boolean correctChecksumAtBuild) {
this.correctChecksumAtBuild = correctChecksumAtBuild;
return this;
}
/**
*
* @param paddingAtBuild paddingAtBuild
* @return this Builder object for method chaining.
*/
public Builder paddingAtBuild(boolean paddingAtBuild) {
this.paddingAtBuild = paddingAtBuild;
return this;
}
@Override
public TcpPacket build() {
return new TcpPacket(this);
}
}
/**
* @author Kaito Yamada
* @since pcap4j 0.9.12
*/
public static final class TcpHeader extends AbstractHeader {
/*
* 0 16 31
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Source Port | Destination Port |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Sequence Number |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Acknowledgment Number |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Data | |U|A|P|R|S|F| |
* | Offset| Reserved |R|C|S|S|Y|I| Window |
* | | |G|K|H|T|N|N| |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Checksum | Urgent Pointer |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Options | Padding |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/
/*
* IPv4 Pseudo Header
*
* 0 16 31
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Src IP Address |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Dst IP Address |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | PAD | Protocol(TCP) | Length |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*
* IPv6 Pseudo Header
*
* 0 16 31
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | |
* + +
* | |
* + Source Address +
* | |
* + +
* | |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | |
* + +
* | |
* + Destination Address +
* | |
* + +
* | |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Upper-Layer Packet Length |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | zero | Next Header |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/
private static final Logger logger = LoggerFactory.getLogger(TcpHeader.class);
/**
*
*/
private static final long serialVersionUID = -795185420055823677L;
private static final int SRC_PORT_OFFSET
= 0;
private static final int SRC_PORT_SIZE
= SHORT_SIZE_IN_BYTES;
private static final int DST_PORT_OFFSET
= SRC_PORT_OFFSET + SRC_PORT_SIZE;
private static final int DST_PORT_SIZE
= SHORT_SIZE_IN_BYTES;
private static final int SEQUENCE_NUMBER_OFFSET
= DST_PORT_OFFSET + DST_PORT_SIZE;
private static final int SEQUENCE_NUMBER_SIZE
= INT_SIZE_IN_BYTES;
private static final int ACKNOWLEDGMENT_NUMBER_OFFSET
= SEQUENCE_NUMBER_OFFSET + SEQUENCE_NUMBER_SIZE;
private static final int ACKNOWLEDGMENT_NUMBER_SIZE
= INT_SIZE_IN_BYTES;
private static final int DATA_OFFSET_AND_RESERVED_AND_CONTROL_BITS_OFFSET
= ACKNOWLEDGMENT_NUMBER_OFFSET + ACKNOWLEDGMENT_NUMBER_SIZE;
private static final int DATA_OFFSET_AND_RESERVED_AND_CONTROL_BITS_SIZE
= SHORT_SIZE_IN_BYTES;
private static final int WINDOW_OFFSET
= DATA_OFFSET_AND_RESERVED_AND_CONTROL_BITS_OFFSET
+ DATA_OFFSET_AND_RESERVED_AND_CONTROL_BITS_SIZE;
private static final int WINDOW_SIZE
= SHORT_SIZE_IN_BYTES;
private static final int CHECKSUM_OFFSET
= WINDOW_OFFSET + WINDOW_SIZE;
private static final int CHECKSUM_SIZE
= SHORT_SIZE_IN_BYTES;
private static final int URGENT_POINTER_OFFSET
= CHECKSUM_OFFSET + CHECKSUM_SIZE;
private static final int URGENT_POINTER_SIZE
= SHORT_SIZE_IN_BYTES;
private static final int OPTIONS_OFFSET
= URGENT_POINTER_OFFSET + URGENT_POINTER_SIZE;
private static final int MIN_TCP_HEADER_SIZE
= URGENT_POINTER_OFFSET + URGENT_POINTER_SIZE;
private static final int IPV4_PSEUDO_HEADER_SIZE = 12;
private static final int IPV6_PSEUDO_HEADER_SIZE = 40;
private final TcpPort srcPort;
private final TcpPort dstPort;
private final int sequenceNumber;
private final int acknowledgmentNumber;
private final byte dataOffset;
private final byte reserved;
private final boolean urg;
private final boolean ack;
private final boolean psh;
private final boolean rst;
private final boolean syn;
private final boolean fin;
private final short window;
private final short checksum;
private final short urgentPointer;
private final List options;
private final byte[] padding;
private TcpHeader(byte[] rawData, int offset, int length) throws IllegalRawDataException {
if (length < MIN_TCP_HEADER_SIZE) {
StringBuilder sb = new StringBuilder(80);
sb.append("The data is too short to build this header(")
.append(MIN_TCP_HEADER_SIZE)
.append(" bytes). data: ")
.append(ByteArrays.toHexString(rawData, " "))
.append(", offset: ")
.append(offset)
.append(", length: ")
.append(length);
throw new IllegalRawDataException(sb.toString());
}
this.srcPort
= TcpPort.getInstance(ByteArrays.getShort(rawData, SRC_PORT_OFFSET + offset));
this.dstPort
= TcpPort.getInstance(ByteArrays.getShort(rawData, DST_PORT_OFFSET + offset));
this.sequenceNumber
= ByteArrays.getInt(rawData, SEQUENCE_NUMBER_OFFSET + offset);
this.acknowledgmentNumber
= ByteArrays.getInt(rawData, ACKNOWLEDGMENT_NUMBER_OFFSET + offset);
short dataOffsetAndReservedAndControlBits
= ByteArrays.getShort(rawData, DATA_OFFSET_AND_RESERVED_AND_CONTROL_BITS_OFFSET + offset);
this.dataOffset = (byte)((dataOffsetAndReservedAndControlBits & 0xF000) >> 12);
this.reserved = (byte)((dataOffsetAndReservedAndControlBits & 0x0FC0) >> 6);
this.urg = (dataOffsetAndReservedAndControlBits & 0x0020) != 0;
this.ack = (dataOffsetAndReservedAndControlBits & 0x0010) != 0;
this.psh = (dataOffsetAndReservedAndControlBits & 0x0008) != 0;
this.rst = (dataOffsetAndReservedAndControlBits & 0x0004) != 0;
this.syn = (dataOffsetAndReservedAndControlBits & 0x0002) != 0;
this.fin = (dataOffsetAndReservedAndControlBits & 0x0001) != 0;
this.window = ByteArrays.getShort(rawData, WINDOW_OFFSET + offset);
this.checksum = ByteArrays.getShort(rawData, CHECKSUM_OFFSET + offset);
this.urgentPointer = ByteArrays.getShort(rawData, URGENT_POINTER_OFFSET + offset);
int headerLength = getDataOffsetAsInt() * 4;
if (length < headerLength) {
StringBuilder sb = new StringBuilder(110);
sb.append("The data is too short to build this header(")
.append(headerLength)
.append(" bytes). data: ")
.append(ByteArrays.toHexString(rawData, " "))
.append(", offset: ")
.append(offset)
.append(", length: ")
.append(length);
throw new IllegalRawDataException(sb.toString());
}
if (headerLength < OPTIONS_OFFSET) {
StringBuilder sb = new StringBuilder(100);
sb.append("The data offset must be equal or more than ")
.append(OPTIONS_OFFSET / 4)
.append(", but it is: ")
.append(getDataOffsetAsInt());
throw new IllegalRawDataException(sb.toString());
}
this.options = new ArrayList();
int currentOffsetInHeader = OPTIONS_OFFSET;
try {
while (currentOffsetInHeader < headerLength) {
TcpOptionKind kind
= TcpOptionKind.getInstance(rawData[currentOffsetInHeader + offset]);
TcpOption newOne;
newOne = PacketFactories
.getFactory(TcpOption.class, TcpOptionKind.class)
.newInstance(
rawData,
currentOffsetInHeader + offset,
headerLength - currentOffsetInHeader,
kind
);
options.add(newOne);
currentOffsetInHeader += newOne.length();
if (newOne.getKind().equals(TcpOptionKind.END_OF_OPTION_LIST)) {
break;
}
}
} catch (Exception e) {
logger.error("Exception occurred during analyzing TCP options: ", e);
}
int paddingLength = headerLength - currentOffsetInHeader;
if (paddingLength != 0) { // paddingLength is positive.
this.padding
= ByteArrays.getSubArray(rawData, currentOffsetInHeader + offset, paddingLength);
}
else {
this.padding = new byte[0];
}
}
private TcpHeader(Builder builder, byte[] payload) {
if ((builder.reserved & 0xC0) != 0) {
throw new IllegalArgumentException(
"Invalid reserved: " + builder.reserved
);
}
this.srcPort = builder.srcPort;
this.dstPort = builder.dstPort;
this.sequenceNumber = builder.sequenceNumber;
this.acknowledgmentNumber = builder.acknowledgmentNumber;
this.reserved = builder.reserved;
this.urg = builder.urg;
this.ack = builder.ack;
this.psh = builder.psh;
this.rst = builder.rst;
this.syn = builder.syn;
this.fin = builder.fin;
this.window = builder.window;
this.urgentPointer = builder.urgentPointer;
if (builder.options != null) {
this.options = new ArrayList(builder.options);
}
else {
this.options = new ArrayList(0);
}
if (builder.paddingAtBuild) {
int mod = measureLengthWithoutPadding() % 4;
if (mod != 0) {
this.padding = new byte[4 - mod];
}
else {
this.padding = new byte[0];
}
}
else {
if (builder.padding != null) {
this.padding = new byte[builder.padding.length];
System.arraycopy(builder.padding, 0, padding, 0, padding.length);
}
else {
this.padding = new byte[0];
}
}
if (builder.correctLengthAtBuild) {
this.dataOffset = (byte)(length() / 4);
}
else {
if ((builder.dataOffset & 0xF0) != 0) {
throw new IllegalArgumentException(
"Invalid dataOffset: " + builder.dataOffset
);
}
this.dataOffset = builder.dataOffset;
}
if (builder.correctChecksumAtBuild) {
if (
(
builder.srcAddr instanceof Inet4Address
&& PacketPropertiesLoader.getInstance().tcpV4CalcChecksum()
)
||
(
builder.srcAddr instanceof Inet6Address
&& PacketPropertiesLoader.getInstance().tcpV6CalcChecksum()
)
) {
this.checksum
= calcChecksum(
builder.srcAddr,
builder.dstAddr,
buildRawData(true),
payload
);
}
else {
this.checksum = (short)0;
}
}
else {
this.checksum = builder.checksum;
}
}
private short calcChecksum(
InetAddress srcAddr, InetAddress dstAddr, byte[] header, byte[] payload
) {
byte[] data;
int destPos;
int totalLength = payload.length + length();
boolean lowerLayerIsIpV4 = srcAddr instanceof Inet4Address;
int pseudoHeaderSize
= lowerLayerIsIpV4 ? IPV4_PSEUDO_HEADER_SIZE
: IPV6_PSEUDO_HEADER_SIZE;
if ((totalLength % 2) != 0) {
data = new byte[totalLength + 1 + pseudoHeaderSize];
destPos = totalLength + 1;
}
else {
data = new byte[totalLength + pseudoHeaderSize];
destPos = totalLength;
}
System.arraycopy(header, 0, data, 0, header.length);
System.arraycopy(payload, 0, data, header.length, payload.length);
// pseudo header
System.arraycopy(
srcAddr.getAddress(), 0,
data, destPos, srcAddr.getAddress().length
);
destPos += srcAddr.getAddress().length;
System.arraycopy(
dstAddr.getAddress(), 0,
data, destPos, dstAddr.getAddress().length
);
destPos += dstAddr.getAddress().length;
if (lowerLayerIsIpV4) {
//data[destPos] = (byte)0;
destPos++;
}
else {
destPos += 3;
}
data[destPos] = IpNumber.TCP.value();
destPos++;
System.arraycopy(
ByteArrays.toByteArray((short)totalLength), 0,
data, destPos, SHORT_SIZE_IN_BYTES
);
destPos += SHORT_SIZE_IN_BYTES;
return ByteArrays.calcChecksum(data);
}
/**
*
* @return srcPort
*/
public TcpPort getSrcPort() { return srcPort; }
/**
*
* @return dstPort
*/
public TcpPort getDstPort() { return dstPort; }
/**
* @return sequenceNumber
*/
public int getSequenceNumber() { return sequenceNumber; }
/**
*
* @return sequenceNumber
*/
public long getSequenceNumberAsLong() {
return sequenceNumber & 0xFFFFFFFFL;
}
/**
* @return acknowledgmentNumber
*/
public int getAcknowledgmentNumber() { return acknowledgmentNumber; }
/**
*
* @return acknowledgmentNumber
*/
public long getAcknowledgmentNumberAsLong() {
return acknowledgmentNumber & 0xFFFFFFFFL;
}
/**
* @return dataOffset
*/
public byte getDataOffset() { return dataOffset; }
/**
* @return dataOffset
*/
public int getDataOffsetAsInt() { return 0xFF & dataOffset; }
/**
* @return reserved
*/
public byte getReserved() { return reserved; }
/**
* @return urg
*/
public boolean getUrg() { return urg; }
/**
* @return ack
*/
public boolean getAck() { return ack; }
/**
* @return psh
*/
public boolean getPsh() { return psh; }
/**
* @return rst
*/
public boolean getRst() { return rst; }
/**
* @return syn
*/
public boolean getSyn() { return syn; }
/**
* @return fin
*/
public boolean getFin() { return fin; }
/**
* @return window
*/
public short getWindow() { return window; }
/**
*
* @return window
*/
public int getWindowAsInt() { return 0xFFFF & window; }
/**
* @return checksum
*/
public short getChecksum() { return checksum; }
/**
* @return urgentPointer
*/
public short getUrgentPointer() { return urgentPointer; }
/**
*
* @return urgentPointer
*/
public int getUrgentPointerAsInt() { return urgentPointer & 0xFFFF; }
/**
* @return options
*/
public List getOptions() {
return new ArrayList(options);
}
/**
*
* @return padding
*/
public byte[] getPadding() {
byte[] copy = new byte[padding.length];
System.arraycopy(padding, 0, copy, 0, padding.length);
return copy;
}
@Override
protected List getRawFields() {
return getRawFields(false);
}
private List getRawFields(boolean zeroInsteadOfChecksum) {
byte flags = 0;
if (fin) { flags = (byte)1; }
if (syn) { flags = (byte)(flags | 2); }
if (rst) { flags = (byte)(flags | 4); }
if (psh) { flags = (byte)(flags | 8); }
if (ack) { flags = (byte)(flags | 16); }
if (urg) { flags = (byte)(flags | 32); }
List rawFields = new ArrayList();
rawFields.add(ByteArrays.toByteArray(srcPort.value()));
rawFields.add(ByteArrays.toByteArray(dstPort.value()));
rawFields.add(ByteArrays.toByteArray(sequenceNumber));
rawFields.add(ByteArrays.toByteArray(acknowledgmentNumber));
rawFields.add(
ByteArrays.toByteArray(
(short)(
(dataOffset << 12)
| (reserved << 6)
| flags
)
)
);
rawFields.add(ByteArrays.toByteArray(window));
rawFields.add(ByteArrays.toByteArray(zeroInsteadOfChecksum ? (short) 0 : checksum));
rawFields.add(ByteArrays.toByteArray(urgentPointer));
for (TcpOption o: options) {
rawFields.add(o.getRawData());
}
rawFields.add(padding);
return rawFields;
}
private byte[] buildRawData(boolean zeroInsteadOfChecksum) {
return ByteArrays.concatenate(getRawFields(zeroInsteadOfChecksum));
}
private int measureLengthWithoutPadding() {
int len = 0;
for (TcpOption o: options) {
len += o.length();
}
return len + MIN_TCP_HEADER_SIZE;
}
@Override
protected int calcLength() {
return measureLengthWithoutPadding() + padding.length;
}
@Override
protected String buildString() {
StringBuilder sb = new StringBuilder();
String ls = System.getProperty("line.separator");
sb.append("[TCP Header (")
.append(length())
.append(" bytes)]")
.append(ls);
sb.append(" Source port: ")
.append(getSrcPort())
.append(ls);
sb.append(" Destination port: ")
.append(getDstPort())
.append(ls);
sb.append(" Sequence Number: ")
.append(getSequenceNumberAsLong())
.append(ls);
sb.append(" Acknowledgment Number: ")
.append(getAcknowledgmentNumberAsLong())
.append(ls);
sb.append(" Data Offset: ")
.append(dataOffset)
.append(" (")
.append(dataOffset * 4)
.append(" [bytes])")
.append(ls);
sb.append(" Reserved: ")
.append(reserved)
.append(ls);
sb.append(" URG: ")
.append(urg)
.append(ls);
sb.append(" ACK: ")
.append(ack)
.append(ls);
sb.append(" PSH: ")
.append(psh)
.append(ls);
sb.append(" RST: ")
.append(rst)
.append(ls);
sb.append(" SYN: ")
.append(syn)
.append(ls);
sb.append(" FIN: ")
.append(fin)
.append(ls);
sb.append(" Window: ")
.append(getWindowAsInt())
.append(ls);
sb.append(" Checksum: 0x")
.append(ByteArrays.toHexString(checksum, ""))
.append(ls);
sb.append(" Urgent Pointer: ")
.append(getUrgentPointerAsInt())
.append(ls);
for (TcpOption opt: options) {
sb.append(" Option: ")
.append(opt)
.append(ls);
}
if (padding.length != 0) {
sb.append(" Padding: 0x")
.append(ByteArrays.toHexString(padding, " "))
.append(ls);
}
return sb.toString();
}
@Override
public boolean equals(Object obj) {
if (obj == this) { return true; }
if (!this.getClass().isInstance(obj)) { return false; }
TcpHeader other = (TcpHeader)obj;
return
checksum == other.checksum
&& sequenceNumber == other.sequenceNumber
&& acknowledgmentNumber == other.acknowledgmentNumber
&& dataOffset == other.dataOffset
&& srcPort.equals(other.srcPort)
&& dstPort.equals(other.dstPort)
&& urg == other.urg
&& ack == other.ack
&& psh == other.psh
&& rst == other.rst
&& syn == other.syn
&& fin == other.fin
&& window == other.window
&& urgentPointer == other.urgentPointer
&& reserved == other.reserved
&& options.equals(other.options)
&& Arrays.equals(padding, other.padding);
}
@Override
protected int calcHashCode() {
int result = 17;
result = 31 * result + srcPort.hashCode();
result = 31 * result + dstPort.hashCode();
result = 31 * result + sequenceNumber;
result = 31 * result + acknowledgmentNumber;
result = 31 * result + dataOffset;
result = 31 * result + reserved;
result = 31 * result + (urg ? 1231 : 1237);
result = 31 * result + (ack ? 1231 : 1237);
result = 31 * result + (psh ? 1231 : 1237);
result = 31 * result + (rst ? 1231 : 1237);
result = 31 * result + (syn ? 1231 : 1237);
result = 31 * result + (fin ? 1231 : 1237);
result = 31 * result + window;
result = 31 * result + checksum;
result = 31 * result + urgentPointer;
result = 31 * result + options.hashCode();
result = 31 * result + Arrays.hashCode(padding);
return result;
}
}
/**
* The interface representing a TCP option.
* If you use {@link org.pcap4j.packet.factory.PropertiesBasedPacketFactory PropertiesBasedPacketFactory},
* classes which implement this interface must implement the following method:
* {@code public static TcpOption newInstance(byte[] rawData, int offset, int length)
* throws IllegalRawDataException}
*
* @author Kaito Yamada
* @since pcap4j 0.9.12
*/
public interface TcpOption extends Serializable {
/**
*
* @return kind
*/
public TcpOptionKind getKind();
/**
*
* @return length
*/
public int length();
/**
*
* @return raw data
*/
public byte[] getRawData();
}
}
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