1 /*
2 * Copyright 2014 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.haproxy;
17
18 /**
19 * The command of an HAProxy proxy protocol header
20 */
21 public enum HAProxyCommand {
22 /**
23 * The LOCAL command represents a connection that was established on purpose by the proxy
24 * without being relayed.
25 */
26 LOCAL(HAProxyConstants.COMMAND_LOCAL_BYTE),
27 /**
28 * The PROXY command represents a connection that was established on behalf of another node,
29 * and reflects the original connection endpoints.
30 */
31 PROXY(HAProxyConstants.COMMAND_PROXY_BYTE);
32
33 /**
34 * The command is specified in the lowest 4 bits of the protocol version and command byte
35 */
36 private static final byte COMMAND_MASK = 0x0f;
37
38 private final byte byteValue;
39
40 /**
41 * Creates a new instance
42 */
43 HAProxyCommand(byte byteValue) {
44 this.byteValue = byteValue;
45 }
46
47 /**
48 * Returns the {@link HAProxyCommand} represented by the lowest 4 bits of the specified byte.
49 *
50 * @param verCmdByte protocol version and command byte
51 */
52 public static HAProxyCommand valueOf(byte verCmdByte) {
53 int cmd = verCmdByte & COMMAND_MASK;
54 switch ((byte) cmd) {
55 case HAProxyConstants.COMMAND_PROXY_BYTE:
56 return PROXY;
57 case HAProxyConstants.COMMAND_LOCAL_BYTE:
58 return LOCAL;
59 default:
60 throw new IllegalArgumentException("unknown command: " + cmd);
61 }
62 }
63
64 /**
65 * Returns the byte value of this command.
66 */
67 public byte byteValue() {
68 return byteValue;
69 }
70 }