LinkAddress.java revision 6eb8a62a26f35ed1c2938945bb86a65f486a8052 
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.Inet4Address;
23import java.net.InetAddress;
24import java.net.InterfaceAddress;
25import java.net.UnknownHostException;
26
27/**
28 * Identifies an address of a network link
29 * @hide
30 */
31public class LinkAddress implements Parcelable {
32    /**
33     * IPv4 or IPv6 address.
34     */
35    private InetAddress address;
36
37    /**
38     * Network prefix length
39     */
40    private int prefixLength;
41
42    private void init(InetAddress address, int prefixLength) {
43        if (address == null || prefixLength < 0 ||
44                ((address instanceof Inet4Address) && prefixLength > 32) ||
45                (prefixLength > 128)) {
46            throw new IllegalArgumentException("Bad LinkAddress params " + address +
47                    "/" + prefixLength);
48        }
49        this.address = address;
50        this.prefixLength = prefixLength;
51    }
52
53    public LinkAddress(InetAddress address, int prefixLength) {
54        init(address, prefixLength);
55    }
56
57    public LinkAddress(InterfaceAddress interfaceAddress) {
58        init(interfaceAddress.getAddress(),
59             interfaceAddress.getNetworkPrefixLength());
60    }
61
62    /**
63     * Constructs a new {@code LinkAddress} from a string such as "192.0.2.5/24" or
64     * "2001:db8::1/64".
65     * @param string The string to parse.
66     */
67    public LinkAddress(String address) {
68        InetAddress inetAddress = null;
69        int prefixLength = -1;
70        try {
71            String [] pieces = address.split("/", 2);
72            prefixLength = Integer.parseInt(pieces[1]);
73            inetAddress = InetAddress.parseNumericAddress(pieces[0]);
74        } catch (NullPointerException e) {            // Null string.
75        } catch (ArrayIndexOutOfBoundsException e) {  // No prefix length.
76        } catch (NumberFormatException e) {           // Non-numeric prefix.
77        } catch (IllegalArgumentException e) {        // Invalid IP address.
78        }
79
80        if (inetAddress == null || prefixLength == -1) {
81            throw new IllegalArgumentException("Bad LinkAddress params " + address);
82        }
83
84        init(inetAddress, prefixLength);
85    }
86
87    @Override
88    public String toString() {
89        return (address == null ? "" : (address.getHostAddress() + "/" + prefixLength));
90    }
91
92    /**
93     * Compares this {@code LinkAddress} instance against the specified address
94     * in {@code obj}. Two addresses are equal if their InetAddress and prefixLength
95     * are equal
96     *
97     * @param obj the object to be tested for equality.
98     * @return {@code true} if both objects are equal, {@code false} otherwise.
99     */
100    @Override
101    public boolean equals(Object obj) {
102        if (!(obj instanceof LinkAddress)) {
103            return false;
104        }
105        LinkAddress linkAddress = (LinkAddress) obj;
106        return this.address.equals(linkAddress.address) &&
107            this.prefixLength == linkAddress.prefixLength;
108    }
109
110    @Override
111    /*
112     * generate hashcode based on significant fields
113     */
114    public int hashCode() {
115        return ((null == address) ? 0 : address.hashCode()) + prefixLength;
116    }
117
118    /**
119     * Returns the InetAddress for this address.
120     */
121    public InetAddress getAddress() {
122        return address;
123    }
124
125    /**
126     * Get network prefix length
127     */
128    public int getNetworkPrefixLength() {
129        return prefixLength;
130    }
131
132    /**
133     * Implement the Parcelable interface
134     * @hide
135     */
136    public int describeContents() {
137        return 0;
138    }
139
140    /**
141     * Implement the Parcelable interface.
142     * @hide
143     */
144    public void writeToParcel(Parcel dest, int flags) {
145        if (address != null) {
146            dest.writeByte((byte)1);
147            dest.writeByteArray(address.getAddress());
148            dest.writeInt(prefixLength);
149        } else {
150            dest.writeByte((byte)0);
151        }
152    }
153
154    /**
155     * Implement the Parcelable interface.
156     * @hide
157     */
158    public static final Creator<LinkAddress> CREATOR =
159        new Creator<LinkAddress>() {
160            public LinkAddress createFromParcel(Parcel in) {
161                InetAddress address = null;
162                int prefixLength = 0;
163                if (in.readByte() == 1) {
164                    try {
165                        address = InetAddress.getByAddress(in.createByteArray());
166                        prefixLength = in.readInt();
167                    } catch (UnknownHostException e) { }
168                }
169                return new LinkAddress(address, prefixLength);
170            }
171
172            public LinkAddress[] newArray(int size) {
173                return new LinkAddress[size];
174            }
175        };
176}
177