1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
|
/*
* Copyright (C) 2021 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.android.net.module.util.structs;
import static com.android.net.module.util.NetworkStackConstants.ICMPV6_ND_OPTION_PIO;
import android.net.IpPrefix;
import androidx.annotation.NonNull;
import com.android.net.module.util.Struct;
import com.android.net.module.util.Struct.Field;
import com.android.net.module.util.Struct.Type;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
/**
* ICMPv6 prefix information option, as per https://tools.ietf.org/html/rfc4861.
*
* 0 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Type | Length | Prefix Length |L|A| Reserved1 |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Valid Lifetime |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Preferred Lifetime |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Reserved2 |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | |
* + +
* | |
* + Prefix +
* | |
* + +
* | |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/
public class PrefixInformationOption extends Struct {
@Field(order = 0, type = Type.S8)
public final byte type;
@Field(order = 1, type = Type.S8)
public final byte length; // Length in 8-byte units
@Field(order = 2, type = Type.S8)
public final byte prefixLen;
@Field(order = 3, type = Type.S8)
// On-link flag, Autonomous address configuration flag, 6-reserved bits
public final byte flags;
@Field(order = 4, type = Type.U32)
public final long validLifetime;
@Field(order = 5, type = Type.U32)
public final long preferredLifetime;
@Field(order = 6, type = Type.S32)
public final int reserved;
@Field(order = 7, type = Type.ByteArray, arraysize = 16)
public final byte[] prefix;
PrefixInformationOption(final byte type, final byte length, final byte prefixLen,
final byte flags, final long validLifetime, final long preferredLifetime,
final int reserved, @NonNull final byte[] prefix) {
this.type = type;
this.length = length;
this.prefixLen = prefixLen;
this.flags = flags;
this.validLifetime = validLifetime;
this.preferredLifetime = preferredLifetime;
this.reserved = reserved;
this.prefix = prefix;
}
/**
* Build a Prefix Information option from the required specified parameters.
*/
public static ByteBuffer build(final IpPrefix prefix, final byte flags,
final long validLifetime, final long preferredLifetime) {
final PrefixInformationOption option = new PrefixInformationOption(
(byte) ICMPV6_ND_OPTION_PIO, (byte) 4 /* option len */,
(byte) prefix.getPrefixLength(), flags, validLifetime, preferredLifetime,
(int) 0, prefix.getRawAddress());
return ByteBuffer.wrap(option.writeToBytes(ByteOrder.BIG_ENDIAN));
}
}
|
