org.pcap4j.packet.DnsRDataCaa Maven / Gradle / Ivy
/*_##########################################################################
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_## Copyright (C) 2017 Pcap4J.org
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_##########################################################################
*/
package org.pcap4j.packet;
import org.pcap4j.packet.DnsResourceRecord.DnsRData;
import org.pcap4j.util.ByteArrays;
/**
* DNS CAA RDATA
*
*
* +0-1-2-3-4-5-6-7-|0-1-2-3-4-5-6-7-|
* | Flags | Tag Length = n |
* +----------------+----------------+...+---------------+
* | Tag char 0 | Tag char 1 |...| Tag char n-1 |
* +----------------+----------------+...+---------------+
* +----------------+----------------+.....+----------------+
* | Value byte 0 | Value byte 1 |.....| Value byte m-1 |
* +----------------+----------------+.....+----------------+
* (m = d - n - 2) where d is the length of the RDATA section.)
*
* where:
* Flags: One octet containing bit flags for record. See rfc for details.
*
* Bit 0, Issuer Critical Flag
* All other bit positions are reserved for future use.
*
* Tag: The property identifier, a sequence of US-ASCII characters.
* Value: A sequence of octets representing the property value.
*
*
* @see RFC 6844
* @author Paulo Pacheco
* @since pcap4j 1.7.2
*/
public final class DnsRDataCaa implements DnsRData {
private static final int CAA_RR_MIN_LEN = 2;
/** A serial UID for serialization. */
private static final long serialVersionUID = -1015182073420031158L;
private final boolean critical;
private final byte reservedFlags;
private final String tag;
private final String value;
/**
* 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 DnsRDataCaa object.
* @throws IllegalRawDataException if parsing the raw data fails.
*/
public static DnsRDataCaa newInstance(byte[] rawData, int offset, int length)
throws IllegalRawDataException {
ByteArrays.validateBounds(rawData, offset, length);
return new DnsRDataCaa(rawData, offset, length);
}
private DnsRDataCaa(byte[] rawData, int offset, int length) throws IllegalRawDataException {
if (length < CAA_RR_MIN_LEN) {
StringBuilder sb = new StringBuilder(200);
sb.append("The data is too short to build a DnsRDataCaa (Min: ")
.append(CAA_RR_MIN_LEN)
.append(" bytes). data: ")
.append(ByteArrays.toHexString(rawData, " "))
.append(", offset: ")
.append(offset)
.append(", length: ")
.append(length);
throw new IllegalRawDataException(sb.toString());
}
this.critical = (rawData[offset] & 0x80) != 0;
this.reservedFlags = (byte) (rawData[offset] & 0x7F);
/* Reading single property entry consisting of a tag-value pair. */
/* Read tag */
int cursor = 1;
int tagLen = rawData[offset + cursor] & 0xFF;
cursor++; /* tag len */
if (length < cursor + tagLen) {
StringBuilder sb = new StringBuilder(200);
sb.append("The data is too short to build a DnsRDataCaa (Tag Length: ")
.append(tagLen)
.append(" bytes). data: ")
.append(ByteArrays.toHexString(rawData, " "))
.append(", offset: ")
.append(offset)
.append(", length: ")
.append(length);
throw new IllegalRawDataException(sb.toString());
}
this.tag = new String(rawData, offset + cursor, tagLen);
cursor += tagLen;
/* Read value */
this.value = new String(rawData, offset + cursor, length - cursor);
}
private DnsRDataCaa(Builder builder) {
if (builder.tag == null || builder.value == null) {
StringBuilder sb = new StringBuilder();
sb.append(" builder.tag: ")
.append(builder.tag)
.append(" builder.value: ")
.append(builder.value);
throw new NullPointerException(sb.toString());
}
if ((builder.reservedFlags & 0x80) != 0) {
StringBuilder sb = new StringBuilder();
sb.append("(builder.reservedFlags & 0x80) must be zero. builder.reservedFlags: ")
.append(builder.reservedFlags);
throw new IllegalArgumentException(sb.toString());
}
if (builder.tag.getBytes().length > 255) {
StringBuilder sb = new StringBuilder();
sb.append("builder.tag.getBytes().length must be less than 256. builder.tag: ")
.append(builder.tag);
throw new IllegalArgumentException(sb.toString());
}
this.critical = builder.critical;
this.reservedFlags = builder.reservedFlags;
this.tag = builder.tag;
this.value = builder.value;
}
/** @return true if the Issuer Critical Flag is set to 1; false otherwise. */
public boolean isCritical() {
return critical;
}
/** @return reservedFlags (Bit 1 to 7 of the Flags field) */
public byte getReservedFlags() {
return reservedFlags;
}
/** @return tag */
public String getTag() {
return tag;
}
/** @return value */
public String getValue() {
return value;
}
@Override
public int length() {
return 1 + 1 + tag.getBytes().length + value.getBytes().length;
}
@Override
public byte[] getRawData() {
byte rawData[] = new byte[length()];
rawData[0] = reservedFlags;
if (critical) {
rawData[0] |= 0x80;
}
byte[] tagBytes = tag.getBytes();
rawData[1] = (byte) tagBytes.length;
int cursor = 2;
System.arraycopy(tagBytes, 0, rawData, cursor, tagBytes.length);
cursor += tagBytes.length;
byte[] valueBytes = value.getBytes();
System.arraycopy(valueBytes, 0, rawData, cursor, valueBytes.length);
return rawData;
}
/** @return a new Builder object populated with this object's fields. */
public Builder getBuilder() {
return new Builder(this);
}
@Override
public String toString(String indent) {
String ls = System.getProperty("line.separator");
StringBuilder sb = new StringBuilder();
sb.append(indent)
.append("CAA RDATA:")
.append(ls)
.append(indent)
.append(" Issuer Critical: ")
.append(critical)
.append(ls)
.append(indent)
.append(" Reserved Flags: 0x")
.append(ByteArrays.toHexString(reservedFlags, ""))
.append(ls)
.append(indent)
.append(" Tag: ")
.append(tag)
.append(ls)
.append(indent)
.append(" Value: ")
.append(value)
.append(ls);
return sb.toString();
}
@Override
public String toString() {
return toString("");
}
@Override
public String toString(String indent, byte[] headerRawData) {
return toString(indent);
}
@Override
public boolean equals(Object o) {
if (this == o) {
return true;
}
if (o == null || getClass() != o.getClass()) {
return false;
}
org.pcap4j.packet.DnsRDataCaa that = (org.pcap4j.packet.DnsRDataCaa) o;
if (critical != that.critical) {
return false;
}
if (reservedFlags != that.reservedFlags) {
return false;
}
if (!tag.equals(that.tag)) {
return false;
}
return value.equals(that.value);
}
@Override
public int hashCode() {
int result = (critical ? 1 : 0);
result = 31 * result + (int) reservedFlags;
result = 31 * result + tag.hashCode();
result = 31 * result + value.hashCode();
return result;
}
/**
* @author Paulo Pacheco
* @since pcap4j 1.7.2
*/
public static final class Builder {
private boolean critical;
private byte reservedFlags;
private String tag;
private String value;
public Builder() {}
private Builder(DnsRDataCaa obj) {
this.critical = obj.critical;
this.reservedFlags = obj.reservedFlags;
this.tag = obj.tag;
this.value = obj.value;
}
/**
* @param critical critical
* @return this Builder object for method chaining.
*/
public Builder critical(boolean critical) {
this.critical = critical;
return this;
}
/**
* @param reservedFlags reservedFlags. The value is between 0 and 127 (inclusive).
* @return this Builder object for method chaining.
*/
public Builder reservedFlags(byte reservedFlags) {
this.reservedFlags = reservedFlags;
return this;
}
/**
* @param tag tag
* @return this Builder object for method chaining.
*/
public Builder tag(String tag) {
this.tag = tag;
return this;
}
/**
* @param value value
* @return this Builder object for method chaining.
*/
public Builder value(String value) {
this.value = value;
return this;
}
/** @return a new DnsRDataCaa object. */
public DnsRDataCaa build() {
return new DnsRDataCaa(this);
}
}
}
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