Shuyi Chen | d7955ce | 2013-05-22 14:51:55 -0700 | [diff] [blame] | 1 | // Copyright (c) 1999-2004 Brian Wellington (bwelling@xbill.org) |
| 2 | |
| 3 | package org.xbill.DNS; |
| 4 | |
| 5 | import java.net.*; |
| 6 | import java.io.*; |
| 7 | |
| 8 | /** |
| 9 | * Address Record - maps a domain name to an Internet address |
| 10 | * |
| 11 | * @author Brian Wellington |
| 12 | */ |
| 13 | |
| 14 | public class ARecord extends Record { |
| 15 | |
| 16 | private static final long serialVersionUID = -2172609200849142323L; |
| 17 | |
| 18 | private int addr; |
| 19 | |
| 20 | ARecord() {} |
| 21 | |
| 22 | Record |
| 23 | getObject() { |
| 24 | return new ARecord(); |
| 25 | } |
| 26 | |
| 27 | private static final int |
| 28 | fromArray(byte [] array) { |
| 29 | return (((array[0] & 0xFF) << 24) | |
| 30 | ((array[1] & 0xFF) << 16) | |
| 31 | ((array[2] & 0xFF) << 8) | |
| 32 | (array[3] & 0xFF)); |
| 33 | } |
| 34 | |
| 35 | private static final byte [] |
| 36 | toArray(int addr) { |
| 37 | byte [] bytes = new byte[4]; |
| 38 | bytes[0] = (byte) ((addr >>> 24) & 0xFF); |
| 39 | bytes[1] = (byte) ((addr >>> 16) & 0xFF); |
| 40 | bytes[2] = (byte) ((addr >>> 8) & 0xFF); |
| 41 | bytes[3] = (byte) (addr & 0xFF); |
| 42 | return bytes; |
| 43 | } |
| 44 | |
| 45 | /** |
| 46 | * Creates an A Record from the given data |
| 47 | * @param address The address that the name refers to |
| 48 | */ |
| 49 | public |
| 50 | ARecord(Name name, int dclass, long ttl, InetAddress address) { |
| 51 | super(name, Type.A, dclass, ttl); |
| 52 | if (Address.familyOf(address) != Address.IPv4) |
| 53 | throw new IllegalArgumentException("invalid IPv4 address"); |
| 54 | addr = fromArray(address.getAddress()); |
| 55 | } |
| 56 | |
| 57 | void |
| 58 | rrFromWire(DNSInput in) throws IOException { |
| 59 | addr = fromArray(in.readByteArray(4)); |
| 60 | } |
| 61 | |
| 62 | void |
| 63 | rdataFromString(Tokenizer st, Name origin) throws IOException { |
| 64 | InetAddress address = st.getAddress(Address.IPv4); |
| 65 | addr = fromArray(address.getAddress()); |
| 66 | } |
| 67 | |
| 68 | /** Converts rdata to a String */ |
| 69 | String |
| 70 | rrToString() { |
| 71 | return (Address.toDottedQuad(toArray(addr))); |
| 72 | } |
| 73 | |
| 74 | /** Returns the Internet address */ |
| 75 | public InetAddress |
| 76 | getAddress() { |
| 77 | try { |
| 78 | return InetAddress.getByAddress(name.toString(), |
| 79 | toArray(addr)); |
| 80 | } catch (UnknownHostException e) { |
| 81 | return null; |
| 82 | } |
| 83 | } |
| 84 | |
| 85 | void |
| 86 | rrToWire(DNSOutput out, Compression c, boolean canonical) { |
| 87 | out.writeU32(((long)addr) & 0xFFFFFFFFL); |
| 88 | } |
| 89 | |
| 90 | } |