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The official Couchbase JVM Core IO Library
// SPDX-License-Identifier: BSD-3-Clause
// Copyright (c) 2003-2004 Brian Wellington ([email protected])
package com.couchbase.client.core.deps.org.xbill.DNS;
import java.net.InetAddress;
import java.net.UnknownHostException;
/**
* A set of functions designed to deal with DNS names used in reverse mappings. For the IPv4 address
* a.b.c.d, the reverse map name is d.c.b.a.in-addr.arpa. For an IPv6 address, the reverse map name
* is ...ip6.arpa.
*
* @author Brian Wellington
*/
public final class ReverseMap {
private static final Name inaddr4 = Name.fromConstantString("in-addr.arpa.");
private static final Name inaddr6 = Name.fromConstantString("ip6.arpa.");
/* Otherwise the class could be instantiated */
private ReverseMap() {}
/**
* Creates a reverse map name corresponding to an address contained in an array of 4 bytes (for an
* IPv4 address) or 16 bytes (for an IPv6 address).
*
* @param addr The address from which to build a name.
* @return The name corresponding to the address in the reverse map.
*/
public static Name fromAddress(byte[] addr) {
if (addr.length != 4 && addr.length != 16) {
throw new IllegalArgumentException("array must contain 4 or 16 elements");
}
StringBuilder sb = new StringBuilder();
if (addr.length == 4) {
for (int i = addr.length - 1; i >= 0; i--) {
sb.append(addr[i] & 0xFF);
if (i > 0) {
sb.append(".");
}
}
} else {
int[] nibbles = new int[2];
for (int i = addr.length - 1; i >= 0; i--) {
nibbles[0] = (addr[i] & 0xFF) >> 4;
nibbles[1] = addr[i] & 0xF;
for (int j = nibbles.length - 1; j >= 0; j--) {
sb.append(Integer.toHexString(nibbles[j]));
if (i > 0 || j > 0) {
sb.append(".");
}
}
}
}
try {
if (addr.length == 4) {
return Name.fromString(sb.toString(), inaddr4);
} else {
return Name.fromString(sb.toString(), inaddr6);
}
} catch (TextParseException e) {
throw new IllegalStateException("name cannot be invalid");
}
}
/**
* Creates a reverse map name corresponding to an address contained in an array of 4 integers
* between 0 and 255 (for an IPv4 address) or 16 integers between 0 and 255 (for an IPv6 address).
*
* @param addr The address from which to build a name.
* @return The name corresponding to the address in the reverse map.
*/
public static Name fromAddress(int[] addr) {
byte[] bytes = new byte[addr.length];
for (int i = 0; i < addr.length; i++) {
if (addr[i] < 0 || addr[i] > 0xFF) {
throw new IllegalArgumentException("array must contain values between 0 and 255");
}
bytes[i] = (byte) addr[i];
}
return fromAddress(bytes);
}
/**
* Creates a reverse map name corresponding to an address contained in an InetAddress.
*
* @param addr The address from which to build a name.
* @return The name corresponding to the address in the reverse map.
*/
public static Name fromAddress(InetAddress addr) {
return fromAddress(addr.getAddress());
}
/**
* Creates a reverse map name corresponding to an address contained in a String.
*
* @param addr The address from which to build a name.
* @return The name corresponding to the address in the reverse map.
* @throws UnknownHostException The string does not contain a valid address.
*/
public static Name fromAddress(String addr, int family) throws UnknownHostException {
byte[] array = Address.toByteArray(addr, family);
if (array == null) {
throw new UnknownHostException("Invalid IP address: " + addr);
}
return fromAddress(array);
}
/**
* Creates a reverse map name corresponding to an address contained in a String.
*
* @param addr The address from which to build a name.
* @return The name corresponding to the address in the reverse map.
* @throws UnknownHostException The string does not contain a valid address.
*/
public static Name fromAddress(String addr) throws UnknownHostException {
byte[] array = Address.toByteArray(addr, Address.IPv4);
if (array == null) {
array = Address.toByteArray(addr, Address.IPv6);
}
if (array == null) {
throw new UnknownHostException("Invalid IP address: " + addr);
}
return fromAddress(array);
}
/**
* Parses the address from a reverse map string.
*
* @param name The string from which to build an address.
* @return The address corresponding to the reverse map string.
* @throws UnknownHostException the passed name is not a valid reverse map.
* @since 3.1
*/
public static InetAddress fromName(String name) throws UnknownHostException, TextParseException {
return fromName(Name.fromString(name));
}
/**
* Parses the address from a reverse map name.
*
* @param name The name from which to build an address.
* @return The address corresponding to the reverse map name.
* @throws UnknownHostException the passed name is not a valid reverse map.
* @since 3.1
*/
public static InetAddress fromName(Name name) throws UnknownHostException {
if (name.labels() <= 3) {
throw new UnknownHostException("Not an arpa address: " + name.toString());
}
byte[] ipBytes;
if (name.subdomain(inaddr4)) {
Name ip = name.relativize(inaddr4);
if (ip.labels() > 4) {
throw new UnknownHostException("Invalid IPv4 arpa address: " + name.toString());
}
ipBytes = new byte[4];
try {
for (int i = 0; i < ip.labels(); i++) {
ipBytes[ip.labels() - i - 1] = (byte) Integer.parseInt(ip.getLabelString(i));
}
} catch (NumberFormatException e) {
throw new UnknownHostException("Invalid IPv4 arpa address: " + name.toString());
}
return InetAddress.getByAddress(ipBytes);
} else if (name.subdomain(inaddr6)) {
Name ip = name.relativize(inaddr6);
if (ip.labels() > 32) {
throw new UnknownHostException("Invalid IPv6 arpa address: " + name.toString());
}
ipBytes = new byte[16];
try {
for (int i = 0; i < ip.labels(); i++) {
ipBytes[(ip.labels() - i - 1) / 2] |=
Byte.parseByte(ip.getLabelString(i), 16) << ((ip.labels() - i) % 2 == 0 ? 0 : 4);
}
} catch (NumberFormatException e) {
throw new UnknownHostException("Invalid IPv6 arpa address: " + name.toString());
}
} else {
throw new UnknownHostException("Not an arpa address: " + name.toString());
}
return InetAddress.getByAddress(ipBytes);
}
}