LinkAddress.java revision 96ca91761e6857c1ca2e4fafe5b35e4b5fefe5a1 
1/*
2 * Copyright (C) 2010 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://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,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package android.net;
18
19import android.os.Parcel;
20import android.os.Parcelable;
21
22import java.net.InetAddress;
23import java.net.InterfaceAddress;
24import java.net.UnknownHostException;
25
26/**
27 * Identifies an address of a network link
28 * @hide
29 */
30public class LinkAddress implements Parcelable {
31    /**
32     * IPv4 or IPv6 address.
33     */
34    private final InetAddress address;
35
36    /**
37     * Network prefix length
38     */
39    private final int prefixLength;
40
41    public LinkAddress(InetAddress address, InetAddress mask) {
42        this.address = address;
43        this.prefixLength = computeprefixLength(mask);
44    }
45
46    public LinkAddress(InetAddress address, int prefixLength) {
47        this.address = address;
48        this.prefixLength = prefixLength;
49    }
50
51    public LinkAddress(InterfaceAddress interfaceAddress) {
52        this.address = interfaceAddress.getAddress();
53        this.prefixLength = interfaceAddress.getNetworkPrefixLength();
54    }
55
56    private static int computeprefixLength(InetAddress mask) {
57        int count = 0;
58        for (byte b : mask.getAddress()) {
59            for (int i = 0; i < 8; ++i) {
60                if ((b & (1 << i)) != 0) {
61                    ++count;
62                }
63            }
64        }
65        return count;
66    }
67
68    @Override
69    public String toString() {
70        return (address == null ? "" : (address.getHostAddress() + "/" + prefixLength));
71    }
72
73    /**
74     * Compares this {@code LinkAddress} instance against the specified address
75     * in {@code obj}. Two addresses are equal if their InetAddress and prefixLength
76     * are equal
77     *
78     * @param obj the object to be tested for equality.
79     * @return {@code true} if both objects are equal, {@code false} otherwise.
80     */
81    @Override
82    public boolean equals(Object obj) {
83        if (!(obj instanceof LinkAddress)) {
84            return false;
85        }
86        LinkAddress linkAddress = (LinkAddress) obj;
87        return this.address.equals(linkAddress.address) &&
88            this.prefixLength == linkAddress.prefixLength;
89    }
90
91    /**
92     * Returns the InetAddress for this address.
93     */
94    public InetAddress getAddress() {
95        return address;
96    }
97
98    /**
99     * Get network prefix length
100     */
101    public int getNetworkPrefixLength() {
102        return prefixLength;
103    }
104
105    /**
106     * Implement the Parcelable interface
107     * @hide
108     */
109    public int describeContents() {
110        return 0;
111    }
112
113    /**
114     * Implement the Parcelable interface.
115     * @hide
116     */
117    public void writeToParcel(Parcel dest, int flags) {
118        if (address != null) {
119            dest.writeByte((byte)1);
120            dest.writeByteArray(address.getAddress());
121            dest.writeInt(prefixLength);
122        } else {
123            dest.writeByte((byte)0);
124        }
125    }
126
127    /**
128     * Implement the Parcelable interface.
129     * @hide
130     */
131    public static final Creator<LinkAddress> CREATOR =
132        new Creator<LinkAddress>() {
133            public LinkAddress createFromParcel(Parcel in) {
134                InetAddress address = null;
135                int prefixLength = 0;
136                if (in.readByte() == 1) {
137                    try {
138                        address = InetAddress.getByAddress(in.createByteArray());
139                        prefixLength = in.readInt();
140                    } catch (UnknownHostException e) { }
141                }
142                return new LinkAddress(address, prefixLength);
143            }
144
145            public LinkAddress[] newArray(int size) {
146                return new LinkAddress[size];
147            }
148        };
149}
150