org.pcap4j.packet.TcpSackPermittedOption Maven / Gradle / Ivy
/*_##########################################################################
_##
_## Copyright (C) 2014 Pcap4J.org
_##
_##########################################################################
*/
package org.pcap4j.packet;
import java.io.ObjectStreamException;
import org.pcap4j.packet.TcpPacket.TcpOption;
import org.pcap4j.packet.namednumber.TcpOptionKind;
import org.pcap4j.util.ByteArrays;
/**
* @author Kaito Yamada
* @since pcap4j 1.2.0
*/
public final class TcpSackPermittedOption implements TcpOption {
/*
* http://tools.ietf.org/html/rfc2018
*
* +---------+---------+
* | Kind=4 | Length=2|
* +---------+---------+
*/
/** */
private static final long serialVersionUID = -5364948716212977767L;
private static final TcpSackPermittedOption INSTANCE = new TcpSackPermittedOption();
private static final TcpOptionKind kind = TcpOptionKind.SACK_PERMITTED;
private static final byte length = 2;
private TcpSackPermittedOption() {}
/** @return the singleton instance of TcpSackPermittedOption. */
public static TcpSackPermittedOption getInstance() {
return INSTANCE;
}
/**
* 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 the singleton instance of TcpSackPermittedOption.
* @throws IllegalRawDataException if parsing the raw data fails.
*/
public static TcpSackPermittedOption newInstance(byte[] rawData, int offset, int length)
throws IllegalRawDataException {
ByteArrays.validateBounds(rawData, offset, length);
if (length < 2) {
StringBuilder sb = new StringBuilder(50);
sb.append("The raw data length must be more than 1. rawData: ")
.append(ByteArrays.toHexString(rawData, " "))
.append(", offset: ")
.append(offset)
.append(", length: ")
.append(length);
throw new IllegalRawDataException(sb.toString());
}
if (rawData[offset] != kind.value()) {
StringBuilder sb = new StringBuilder(100);
sb.append("The kind must be: ")
.append(kind.valueAsString())
.append(" rawData: ")
.append(ByteArrays.toHexString(rawData, " "))
.append(", offset: ")
.append(offset)
.append(", length: ")
.append(length);
throw new IllegalRawDataException(sb.toString());
}
if (rawData[1 + offset] != 2) {
throw new IllegalRawDataException(
"The value of length field must be 2 but: " + rawData[1 + offset]);
}
return INSTANCE;
}
@Override
public TcpOptionKind getKind() {
return kind;
}
/** @return length */
public byte getLength() {
return length;
}
/** @return length */
public int getLengthAsInt() {
return 0xFF & length;
}
@Override
public int length() {
return 2;
}
@Override
public byte[] getRawData() {
byte[] rawData = new byte[length()];
rawData[0] = kind.value();
rawData[1] = length;
return rawData;
}
@Override
public String toString() {
StringBuilder sb = new StringBuilder();
sb.append("[Kind: ").append(kind);
sb.append("] [Length: ").append(getLengthAsInt()).append(" bytes]");
return sb.toString();
}
// Override deserializer to keep singleton
@SuppressWarnings("static-method")
private Object readResolve() throws ObjectStreamException {
return INSTANCE;
}
}
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