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The core module of Pcap4J.
/*_##########################################################################
_##
_## Copyright (C) 2016 Pcap4J.org
_##
_##########################################################################
*/
package org.pcap4j.packet;
import static org.pcap4j.util.ByteArrays.*;
import java.io.Serializable;
import org.pcap4j.packet.namednumber.DnsClass;
import org.pcap4j.packet.namednumber.DnsResourceRecordType;
import org.pcap4j.util.ByteArrays;
/**
* DNS Question
*
*
* 1 1 1 1 1 1
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
* +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
* | |
* / QNAME /
* / /
* +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
* | QTYPE |
* +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
* | QCLASS |
* +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
*
*
* @see RFC 1035
* @author Kaito Yamada
* @since pcap4j 1.7.1
*/
public final class DnsQuestion implements Serializable {
/** */
private static final long serialVersionUID = -709060058515052575L;
private final DnsDomainName qName;
private final DnsResourceRecordType qType;
private final DnsClass qClass;
/**
* 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 DnsQuestion object.
* @throws IllegalRawDataException if parsing the raw data fails.
*/
public static DnsQuestion newInstance(byte[] rawData, int offset, int length)
throws IllegalRawDataException {
ByteArrays.validateBounds(rawData, offset, length);
return new DnsQuestion(rawData, offset, length);
}
private DnsQuestion(byte[] rawData, int offset, int length) throws IllegalRawDataException {
int cursor = 0;
this.qName = DnsDomainName.newInstance(rawData, offset, length);
cursor += qName.length();
if (length - cursor < SHORT_SIZE_IN_BYTES * 2) {
StringBuilder sb = new StringBuilder(200);
sb.append("The data is too short to build qType an qClass of DnsQuestion. data: ")
.append(ByteArrays.toHexString(rawData, " "))
.append(", offset: ")
.append(offset)
.append(", length: ")
.append(length)
.append(", cursor: ")
.append(cursor);
throw new IllegalRawDataException(sb.toString());
}
this.qType = DnsResourceRecordType.getInstance(ByteArrays.getShort(rawData, offset + cursor));
cursor += SHORT_SIZE_IN_BYTES;
this.qClass = DnsClass.getInstance(ByteArrays.getShort(rawData, offset + cursor));
}
private DnsQuestion(Builder builder) {
if (builder == null
|| builder.qName == null
|| builder.qType == null
|| builder.qClass == null) {
StringBuilder sb = new StringBuilder();
sb.append("builder")
.append(builder)
.append(" builder.qName: ")
.append(builder.qName)
.append(" builder.qType: ")
.append(builder.qType)
.append(" builder.qClass: ")
.append(builder.qClass);
throw new NullPointerException(sb.toString());
}
this.qName = builder.qName;
this.qType = builder.qType;
this.qClass = builder.qClass;
}
/** @return qName */
public DnsDomainName getQName() {
return qName;
}
/** @return qType */
public DnsResourceRecordType getQType() {
return qType;
}
/** @return qClass */
public DnsClass getQClass() {
return qClass;
}
/** @return a new Builder object populated with this object's fields. */
public Builder getBuilder() {
return new Builder(this);
}
/** @return the raw data. */
public byte[] getRawData() {
byte[] data = new byte[length()];
int cursor = 0;
byte[] rawQName = qName.getRawData();
System.arraycopy(rawQName, 0, data, 0, rawQName.length);
cursor += rawQName.length;
System.arraycopy(ByteArrays.toByteArray(qType.value()), 0, data, cursor, SHORT_SIZE_IN_BYTES);
cursor += SHORT_SIZE_IN_BYTES;
System.arraycopy(ByteArrays.toByteArray(qClass.value()), 0, data, cursor, SHORT_SIZE_IN_BYTES);
return data;
}
/** @return length */
public int length() {
return qName.length() + SHORT_SIZE_IN_BYTES * 2;
}
@Override
public String toString() {
return convertToString("", null);
}
/**
* @param indent indent
* @return String representation of this object.
*/
public String toString(String indent) {
return convertToString(indent, null);
}
/**
* @param indent indent
* @param headerRawData the raw data of the DNS header including this question.
* @return String representation of this object.
*/
public String toString(String indent, byte[] headerRawData) {
if (headerRawData == null) {
throw new NullPointerException("headerRawData is null.");
}
return convertToString(indent, headerRawData);
}
private String convertToString(String indent, byte[] headerRawData) {
StringBuilder sb = new StringBuilder();
String ls = System.getProperty("line.separator");
sb.append(indent)
.append("QNAME: ")
.append(headerRawData != null ? qName.toString(headerRawData) : qName)
.append(ls)
.append(indent)
.append("QTYPE: ")
.append(qType)
.append(ls)
.append(indent)
.append("QCLASS: ")
.append(qClass)
.append(ls);
return sb.toString();
}
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + qClass.hashCode();
result = prime * result + qName.hashCode();
result = prime * result + qType.hashCode();
return result;
}
@Override
public boolean equals(Object obj) {
if (this == obj) {
return true;
}
if (obj == null) {
return false;
}
if (getClass() != obj.getClass()) {
return false;
}
DnsQuestion other = (DnsQuestion) obj;
if (!qClass.equals(other.qClass)) {
return false;
}
if (!qName.equals(other.qName)) {
return false;
}
if (!qType.equals(other.qType)) {
return false;
}
return true;
}
/**
* @author Kaito Yamada
* @since pcap4j 1.7.1
*/
public static final class Builder {
private DnsDomainName qName;
private DnsResourceRecordType qType;
private DnsClass qClass;
/** */
public Builder() {}
private Builder(DnsQuestion obj) {
this.qName = obj.qName;
this.qType = obj.qType;
this.qClass = obj.qClass;
}
/**
* @param qName qName
* @return this Builder object for method chaining.
*/
public Builder qName(DnsDomainName qName) {
this.qName = qName;
return this;
}
/**
* @param qType qType
* @return this Builder object for method chaining.
*/
public Builder qType(DnsResourceRecordType qType) {
this.qType = qType;
return this;
}
/**
* @param qClass qClass
* @return this Builder object for method chaining.
*/
public Builder qClass(DnsClass qClass) {
this.qClass = qClass;
return this;
}
/** @return a new DnsQuestion object. */
public DnsQuestion build() {
return new DnsQuestion(this);
}
}
}
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