1 /*
2 * Copyright 2015 The Netty Project
3 *
4 * The Netty Project licenses this file to you under the Apache License,
5 * version 2.0 (the "License"); you may not use this file except in compliance
6 * with the License. You may obtain a copy of the License at:
7 *
8 * https://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
12 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
13 * License for the specific language governing permissions and limitations
14 * under the License.
15 */
16 package io.netty.handler.codec.dns;
17
18 import static io.netty.util.internal.ObjectUtil.checkNotNull;
19
20 /**
21 * The DNS {@code OpCode} as defined in <a href="https://tools.ietf.org/html/rfc2929">RFC2929</a>.
22 */
23 public class DnsOpCode implements Comparable<DnsOpCode> {
24
25 /**
26 * The 'Query' DNS OpCode, as defined in <a href="https://tools.ietf.org/html/rfc1035">RFC1035</a>.
27 */
28 public static final DnsOpCode QUERY = new DnsOpCode(0x00, "QUERY");
29
30 /**
31 * The 'IQuery' DNS OpCode, as defined in <a href="https://tools.ietf.org/html/rfc1035">RFC1035</a>.
32 */
33 public static final DnsOpCode IQUERY = new DnsOpCode(0x01, "IQUERY");
34
35 /**
36 * The 'Status' DNS OpCode, as defined in <a href="https://tools.ietf.org/html/rfc1035">RFC1035</a>.
37 */
38 public static final DnsOpCode STATUS = new DnsOpCode(0x02, "STATUS");
39
40 /**
41 * The 'Notify' DNS OpCode, as defined in <a href="https://tools.ietf.org/html/rfc1996">RFC1996</a>.
42 */
43 public static final DnsOpCode NOTIFY = new DnsOpCode(0x04, "NOTIFY");
44
45 /**
46 * The 'Update' DNS OpCode, as defined in <a href="https://tools.ietf.org/html/rfc2136">RFC2136</a>.
47 */
48 public static final DnsOpCode UPDATE = new DnsOpCode(0x05, "UPDATE");
49
50 /**
51 * Returns the {@link DnsOpCode} instance of the specified byte value.
52 */
53 public static DnsOpCode valueOf(int b) {
54 switch (b) {
55 case 0x00:
56 return QUERY;
57 case 0x01:
58 return IQUERY;
59 case 0x02:
60 return STATUS;
61 case 0x04:
62 return NOTIFY;
63 case 0x05:
64 return UPDATE;
65 default:
66 break;
67 }
68
69 return new DnsOpCode(b);
70 }
71
72 private final byte byteValue;
73 private final String name;
74 private String text;
75
76 private DnsOpCode(int byteValue) {
77 this(byteValue, "UNKNOWN");
78 }
79
80 public DnsOpCode(int byteValue, String name) {
81 this.byteValue = (byte) byteValue;
82 this.name = checkNotNull(name, "name");
83 }
84
85 public byte byteValue() {
86 return byteValue;
87 }
88
89 @Override
90 public int hashCode() {
91 return byteValue;
92 }
93
94 @Override
95 public boolean equals(Object obj) {
96 if (this == obj) {
97 return true;
98 }
99
100 if (!(obj instanceof DnsOpCode)) {
101 return false;
102 }
103
104 return byteValue == ((DnsOpCode) obj).byteValue;
105 }
106
107 @Override
108 public int compareTo(DnsOpCode o) {
109 return byteValue - o.byteValue;
110 }
111
112 @Override
113 public String toString() {
114 String text = this.text;
115 if (text == null) {
116 this.text = text = name + '(' + (byteValue & 0xFF) + ')';
117 }
118 return text;
119 }
120 }