/*
* Copyright (C) 2014 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 android.net;
import android.net.NetworkUtils;
import android.os.Parcelable;
import android.os.Parcel;
import android.system.ErrnoException;
import java.io.FileDescriptor;
import java.io.IOException;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.MalformedURLException;
import java.net.ProxySelector;
import java.net.Socket;
import java.net.SocketAddress;
import java.net.SocketException;
import java.net.UnknownHostException;
import java.net.URL;
import java.net.URLConnection;
import java.net.URLStreamHandler;
import java.util.concurrent.atomic.AtomicReference;
import javax.net.SocketFactory;
import com.android.okhttp.ConnectionPool;
import com.android.okhttp.HostResolver;
import com.android.okhttp.HttpHandler;
import com.android.okhttp.HttpsHandler;
import com.android.okhttp.OkHttpClient;
/**
* Identifies a {@code Network}. This is supplied to applications via
* {@link ConnectivityManager.NetworkCallback} in response to the active
* {@link ConnectivityManager#requestNetwork} or passive
* {@link ConnectivityManager#registerNetworkCallback} calls.
* It is used to direct traffic to the given {@code Network}, either on a {@link Socket} basis
* through a targeted {@link SocketFactory} or process-wide via
* {@link ConnectivityManager#setProcessDefaultNetwork}.
*/
public class Network implements Parcelable {
/**
* @hide
*/
public final int netId;
// Objects used to perform per-network operations such as getSocketFactory
// and openConnection, and a lock to protect access to them.
private volatile NetworkBoundSocketFactory mNetworkBoundSocketFactory = null;
// mLock should be used to control write access to mConnectionPool and mHostResolver.
// maybeInitHttpClient() must be called prior to reading either variable.
private volatile ConnectionPool mConnectionPool = null;
private volatile HostResolver mHostResolver = null;
private Object mLock = new Object();
// Default connection pool values. These are evaluated at startup, just
// like the OkHttp code. Also like the OkHttp code, we will throw parse
// exceptions at class loading time if the properties are set but are not
// valid integers.
private static final boolean httpKeepAlive =
Boolean.parseBoolean(System.getProperty("http.keepAlive", "true"));
private static final int httpMaxConnections =
httpKeepAlive ? Integer.parseInt(System.getProperty("http.maxConnections", "5")) : 0;
private static final long httpKeepAliveDurationMs =
Long.parseLong(System.getProperty("http.keepAliveDuration", "300000")); // 5 minutes.
/**
* @hide
*/
public Network(int netId) {
this.netId = netId;
}
/**
* @hide
*/
public Network(Network that) {
this.netId = that.netId;
}
/**
* Operates the same as {@code InetAddress.getAllByName} except that host
* resolution is done on this network.
*
* @param host the hostname or literal IP string to be resolved.
* @return the array of addresses associated with the specified host.
* @throws UnknownHostException if the address lookup fails.
*/
public InetAddress[] getAllByName(String host) throws UnknownHostException {
return InetAddress.getAllByNameOnNet(host, netId);
}
/**
* Operates the same as {@code InetAddress.getByName} except that host
* resolution is done on this network.
*
* @param host
* the hostName to be resolved to an address or {@code null}.
* @return the {@code InetAddress} instance representing the host.
* @throws UnknownHostException
* if the address lookup fails.
*/
public InetAddress getByName(String host) throws UnknownHostException {
return InetAddress.getByNameOnNet(host, netId);
}
/**
* A {@code SocketFactory} that produces {@code Socket}'s bound to this network.
*/
private class NetworkBoundSocketFactory extends SocketFactory {
private final int mNetId;
public NetworkBoundSocketFactory(int netId) {
super();
mNetId = netId;
}
private Socket connectToHost(String host, int port, SocketAddress localAddress)
throws IOException {
// Lookup addresses only on this Network.
InetAddress[] hostAddresses = getAllByName(host);
// Try all addresses.
for (int i = 0; i < hostAddresses.length; i++) {
try {
Socket socket = createSocket();
if (localAddress != null) socket.bind(localAddress);
socket.connect(new InetSocketAddress(hostAddresses[i], port));
return socket;
} catch (IOException e) {
if (i == (hostAddresses.length - 1)) throw e;
}
}
throw new UnknownHostException(host);
}
@Override
public Socket createSocket(String host, int port, InetAddress localHost, int localPort) throws IOException {
return connectToHost(host, port, new InetSocketAddress(localHost, localPort));
}
@Override
public Socket createSocket(InetAddress address, int port, InetAddress localAddress,
int localPort) throws IOException {
Socket socket = createSocket();
socket.bind(new InetSocketAddress(localAddress, localPort));
socket.connect(new InetSocketAddress(address, port));
return socket;
}
@Override
public Socket createSocket(InetAddress host, int port) throws IOException {
Socket socket = createSocket();
socket.connect(new InetSocketAddress(host, port));
return socket;
}
@Override
public Socket createSocket(String host, int port) throws IOException {
return connectToHost(host, port, null);
}
@Override
public Socket createSocket() throws IOException {
Socket socket = new Socket();
bindSocket(socket);
return socket;
}
}
/**
* Returns a {@link SocketFactory} bound to this network. Any {@link Socket} created by
* this factory will have its traffic sent over this {@code Network}. Note that if this
* {@code Network} ever disconnects, this factory and any {@link Socket} it produced in the
* past or future will cease to work.
*
* @return a {@link SocketFactory} which produces {@link Socket} instances bound to this
* {@code Network}.
*/
public SocketFactory getSocketFactory() {
if (mNetworkBoundSocketFactory == null) {
synchronized (mLock) {
if (mNetworkBoundSocketFactory == null) {
mNetworkBoundSocketFactory = new NetworkBoundSocketFactory(netId);
}
}
}
return mNetworkBoundSocketFactory;
}
// TODO: This creates a connection pool and host resolver for
// every Network object, instead of one for every NetId. This is
// suboptimal, because an app could potentially have more than one
// Network object for the same NetId, causing increased memory footprint
// and performance penalties due to lack of connection reuse (connection
// setup time, congestion window growth time, etc.).
//
// Instead, investigate only having one connection pool and host resolver
// for every NetId, perhaps by using a static HashMap of NetIds to
// connection pools and host resolvers. The tricky part is deciding when
// to remove a map entry; a WeakHashMap shouldn't be used because whether
// a Network is referenced doesn't correlate with whether a new Network
// will be instantiated in the near future with the same NetID. A good
// solution would involve purging empty (or when all connections are timed
// out) ConnectionPools.
private void maybeInitHttpClient() {
synchronized (mLock) {
if (mHostResolver == null) {
mHostResolver = new HostResolver() {
@Override
public InetAddress[] getAllByName(String host) throws UnknownHostException {
return Network.this.getAllByName(host);
}
};
}
if (mConnectionPool == null) {
mConnectionPool = new ConnectionPool(httpMaxConnections,
httpKeepAliveDurationMs);
}
}
}
/**
* Opens the specified {@link URL} on this {@code Network}, such that all traffic will be sent
* on this Network. The URL protocol must be {@code HTTP} or {@code HTTPS}.
*
* @return a {@code URLConnection} to the resource referred to by this URL.
* @throws MalformedURLException if the URL protocol is not HTTP or HTTPS.
* @throws IOException if an error occurs while opening the connection.
* @see java.net.URL#openConnection()
*/
public URLConnection openConnection(URL url) throws IOException {
final ConnectivityManager cm = ConnectivityManager.getInstance();
// TODO: Should this be optimized to avoid fetching the global proxy for every request?
ProxyInfo proxyInfo = cm.getGlobalProxy();
if (proxyInfo == null) {
// TODO: Should this be optimized to avoid fetching LinkProperties for every request?
final LinkProperties lp = cm.getLinkProperties(this);
if (lp != null) proxyInfo = lp.getHttpProxy();
}
java.net.Proxy proxy = null;
if (proxyInfo != null) {
proxy = proxyInfo.makeProxy();
} else {
proxy = java.net.Proxy.NO_PROXY;
}
return openConnection(url, proxy);
}
/**
* Opens the specified {@link URL} on this {@code Network}, such that all traffic will be sent
* on this Network. The URL protocol must be {@code HTTP} or {@code HTTPS}.
*
* @param proxy the proxy through which the connection will be established.
* @return a {@code URLConnection} to the resource referred to by this URL.
* @throws MalformedURLException if the URL protocol is not HTTP or HTTPS.
* @throws IllegalArgumentException if the argument proxy is null.
* @throws IOException if an error occurs while opening the connection.
* @see java.net.URL#openConnection()
* @hide
*/
public URLConnection openConnection(URL url, java.net.Proxy proxy) throws IOException {
if (proxy == null) throw new IllegalArgumentException("proxy is null");
maybeInitHttpClient();
String protocol = url.getProtocol();
OkHttpClient client;
// TODO: HttpHandler creates OkHttpClients that share the default ResponseCache.
// Could this cause unexpected behavior?
if (protocol.equals("http")) {
client = HttpHandler.createHttpOkHttpClient(proxy);
} else if (protocol.equals("https")) {
client = HttpsHandler.createHttpsOkHttpClient(proxy);
} else {
// OkHttpClient only supports HTTP and HTTPS and returns a null URLStreamHandler if
// passed another protocol.
throw new MalformedURLException("Invalid URL or unrecognized protocol " + protocol);
}
return client.setSocketFactory(getSocketFactory())
.setHostResolver(mHostResolver)
.setConnectionPool(mConnectionPool)
.open(url);
}
/**
* Binds the specified {@link DatagramSocket} to this {@code Network}. All data traffic on the
* socket will be sent on this {@code Network}, irrespective of any process-wide network binding
* set by {@link ConnectivityManager#setProcessDefaultNetwork}. The socket must not be
* connected.
*/
public void bindSocket(DatagramSocket socket) throws IOException {
// Apparently, the kernel doesn't update a connected UDP socket's routing upon mark changes.
if (socket.isConnected()) {
throw new SocketException("Socket is connected");
}
// Query a property of the underlying socket to ensure that the socket's file descriptor
// exists, is available to bind to a network and is not closed.
socket.getReuseAddress();
bindSocketFd(socket.getFileDescriptor$());
}
/**
* Binds the specified {@link Socket} to this {@code Network}. All data traffic on the socket
* will be sent on this {@code Network}, irrespective of any process-wide network binding set by
* {@link ConnectivityManager#setProcessDefaultNetwork}. The socket must not be connected.
*/
public void bindSocket(Socket socket) throws IOException {
// Apparently, the kernel doesn't update a connected TCP socket's routing upon mark changes.
if (socket.isConnected()) {
throw new SocketException("Socket is connected");
}
// Query a property of the underlying socket to ensure that the socket's file descriptor
// exists, is available to bind to a network and is not closed.
socket.getReuseAddress();
bindSocketFd(socket.getFileDescriptor$());
}
private void bindSocketFd(FileDescriptor fd) throws IOException {
int err = NetworkUtils.bindSocketToNetwork(fd.getInt$(), netId);
if (err != 0) {
// bindSocketToNetwork returns negative errno.
throw new ErrnoException("Binding socket to network " + netId, -err)
.rethrowAsSocketException();
}
}
// implement the Parcelable interface
public int describeContents() {
return 0;
}
public void writeToParcel(Parcel dest, int flags) {
dest.writeInt(netId);
}
public static final Creator<Network> CREATOR =
new Creator<Network>() {
public Network createFromParcel(Parcel in) {
int netId = in.readInt();
return new Network(netId);
}
public Network[] newArray(int size) {
return new Network[size];
}
};
@Override
public boolean equals(Object obj) {
if (obj instanceof Network == false) return false;
Network other = (Network)obj;
return this.netId == other.netId;
}
@Override
public int hashCode() {
return netId * 11;
}
@Override
public String toString() {
return Integer.toString(netId);
}
}
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