Network.java revision 32a58f00d388584f5f47c0d5d4c74ce7c8457d78
1/* 2 * Copyright (C) 2014 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.net.NetworkUtils; 20import android.os.Parcelable; 21import android.os.Parcel; 22 23import java.io.IOException; 24import java.net.InetAddress; 25import java.net.InetSocketAddress; 26import java.net.Socket; 27import java.net.SocketException; 28import java.net.UnknownHostException; 29import javax.net.SocketFactory; 30 31/** 32 * Identifies a {@code Network}. This is supplied to applications via 33 * {@link ConnectivityManager.NetworkCallback} in response to the active 34 * {@link ConnectivityManager#requestNetwork} or passive 35 * {@link ConnectivityManager#registerNetworkCallback} calls. 36 * It is used to direct traffic to the given {@code Network}, either on a {@link Socket} basis 37 * through a targeted {@link SocketFactory} or process-wide via 38 * {@link ConnectivityManager#setProcessDefaultNetwork}. 39 */ 40public class Network implements Parcelable { 41 42 /** 43 * @hide 44 */ 45 public final int netId; 46 47 private NetworkBoundSocketFactory mNetworkBoundSocketFactory = null; 48 49 /** 50 * @hide 51 */ 52 public Network(int netId) { 53 this.netId = netId; 54 } 55 56 /** 57 * @hide 58 */ 59 public Network(Network that) { 60 this.netId = that.netId; 61 } 62 63 /** 64 * Operates the same as {@code InetAddress.getAllByName} except that host 65 * resolution is done on this network. 66 * 67 * @param host the hostname or literal IP string to be resolved. 68 * @return the array of addresses associated with the specified host. 69 * @throws UnknownHostException if the address lookup fails. 70 */ 71 public InetAddress[] getAllByName(String host) throws UnknownHostException { 72 return InetAddress.getAllByNameOnNet(host, netId); 73 } 74 75 /** 76 * Operates the same as {@code InetAddress.getByName} except that host 77 * resolution is done on this network. 78 * 79 * @param host 80 * the hostName to be resolved to an address or {@code null}. 81 * @return the {@code InetAddress} instance representing the host. 82 * @throws UnknownHostException 83 * if the address lookup fails. 84 */ 85 public InetAddress getByName(String host) throws UnknownHostException { 86 return InetAddress.getByNameOnNet(host, netId); 87 } 88 89 /** 90 * A {@code SocketFactory} that produces {@code Socket}'s bound to this network. 91 */ 92 private class NetworkBoundSocketFactory extends SocketFactory { 93 private final int mNetId; 94 95 public NetworkBoundSocketFactory(int netId) { 96 super(); 97 mNetId = netId; 98 } 99 100 private void connectToHost(Socket socket, String host, int port) throws IOException { 101 // Lookup addresses only on this Network. 102 InetAddress[] hostAddresses = getAllByName(host); 103 // Try all but last address ignoring exceptions. 104 for (int i = 0; i < hostAddresses.length - 1; i++) { 105 try { 106 socket.connect(new InetSocketAddress(hostAddresses[i], port)); 107 return; 108 } catch (IOException e) { 109 } 110 } 111 // Try last address. Do throw exceptions. 112 socket.connect(new InetSocketAddress(hostAddresses[hostAddresses.length - 1], port)); 113 } 114 115 @Override 116 public Socket createSocket(String host, int port, InetAddress localHost, int localPort) throws IOException { 117 Socket socket = createSocket(); 118 socket.bind(new InetSocketAddress(localHost, localPort)); 119 connectToHost(socket, host, port); 120 return socket; 121 } 122 123 @Override 124 public Socket createSocket(InetAddress address, int port, InetAddress localAddress, 125 int localPort) throws IOException { 126 Socket socket = createSocket(); 127 socket.bind(new InetSocketAddress(localAddress, localPort)); 128 socket.connect(new InetSocketAddress(address, port)); 129 return socket; 130 } 131 132 @Override 133 public Socket createSocket(InetAddress host, int port) throws IOException { 134 Socket socket = createSocket(); 135 socket.connect(new InetSocketAddress(host, port)); 136 return socket; 137 } 138 139 @Override 140 public Socket createSocket(String host, int port) throws IOException { 141 Socket socket = createSocket(); 142 connectToHost(socket, host, port); 143 return socket; 144 } 145 146 @Override 147 public Socket createSocket() throws IOException { 148 Socket socket = new Socket(); 149 // Query a property of the underlying socket to ensure the underlying 150 // socket exists so a file descriptor is available to bind to a network. 151 socket.getReuseAddress(); 152 if (!NetworkUtils.bindSocketToNetwork(socket.getFileDescriptor$().getInt$(), mNetId)) { 153 throw new SocketException("Failed to bind socket to network."); 154 } 155 return socket; 156 } 157 } 158 159 /** 160 * Returns a {@link SocketFactory} bound to this network. Any {@link Socket} created by 161 * this factory will have its traffic sent over this {@code Network}. Note that if this 162 * {@code Network} ever disconnects, this factory and any {@link Socket} it produced in the 163 * past or future will cease to work. 164 * 165 * @return a {@link SocketFactory} which produces {@link Socket} instances bound to this 166 * {@code Network}. 167 */ 168 public SocketFactory getSocketFactory() { 169 if (mNetworkBoundSocketFactory == null) { 170 mNetworkBoundSocketFactory = new NetworkBoundSocketFactory(netId); 171 } 172 return mNetworkBoundSocketFactory; 173 } 174 175 // implement the Parcelable interface 176 public int describeContents() { 177 return 0; 178 } 179 public void writeToParcel(Parcel dest, int flags) { 180 dest.writeInt(netId); 181 } 182 183 public static final Creator<Network> CREATOR = 184 new Creator<Network>() { 185 public Network createFromParcel(Parcel in) { 186 int netId = in.readInt(); 187 188 return new Network(netId); 189 } 190 191 public Network[] newArray(int size) { 192 return new Network[size]; 193 } 194 }; 195 196 @Override 197 public boolean equals(Object obj) { 198 if (obj instanceof Network == false) return false; 199 Network other = (Network)obj; 200 return this.netId == other.netId; 201 } 202 203 @Override 204 public int hashCode() { 205 return netId * 11; 206 } 207 208 @Override 209 public String toString() { 210 return Integer.toString(netId); 211 } 212} 213