Merge branch '845-wifi-without-internet' into 'maintenance-0.16'

Backport: Use WifiManager to get wifi network information

See merge request akwizgran/briar!748

bramble-android/src/main/java/org/briarproject/bramble/plugin/tcp/AndroidLanTcpPlugin.java

@@ -5,20 +5,33 @@ import android.content.Context;
 import android.content.Intent;
 import android.content.IntentFilter;
 import android.net.ConnectivityManager;
+import android.net.Network;
 import android.net.NetworkInfo;
+import android.net.wifi.WifiInfo;
+import android.net.wifi.WifiManager;
 
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.Backoff;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPluginCallback;
 
+import java.io.IOException;
+import java.net.InetAddress;
+import java.net.Socket;
+import java.net.UnknownHostException;
+import java.util.Collection;
 import java.util.concurrent.Executor;
 import java.util.logging.Logger;
 
 import javax.annotation.Nullable;
+import javax.net.SocketFactory;
 
 import static android.content.Context.CONNECTIVITY_SERVICE;
+import static android.content.Context.WIFI_SERVICE;
 import static android.net.ConnectivityManager.CONNECTIVITY_ACTION;
 import static android.net.ConnectivityManager.TYPE_WIFI;
+import static android.os.Build.VERSION.SDK_INT;
+import static java.util.Collections.emptyList;
+import static java.util.Collections.singletonList;
 
 @NotNullByDefault
 class AndroidLanTcpPlugin extends LanTcpPlugin {
@@ -27,15 +40,26 @@ class AndroidLanTcpPlugin extends LanTcpPlugin {
 			Logger.getLogger(AndroidLanTcpPlugin.class.getName());
 
 	private final Context appContext;
+	private final ConnectivityManager connectivityManager;
+	@Nullable
+	private final WifiManager wifiManager;
 
 	@Nullable
 	private volatile BroadcastReceiver networkStateReceiver = null;
+	private volatile SocketFactory socketFactory;
 
 	AndroidLanTcpPlugin(Executor ioExecutor, Backoff backoff,
 			Context appContext, DuplexPluginCallback callback, int maxLatency,
 			int maxIdleTime) {
 		super(ioExecutor, backoff, callback, maxLatency, maxIdleTime);
 		this.appContext = appContext;
+		ConnectivityManager connectivityManager = (ConnectivityManager)
+				appContext.getSystemService(CONNECTIVITY_SERVICE);
+		if (connectivityManager == null) throw new AssertionError();
+		this.connectivityManager = connectivityManager;
+		wifiManager = (WifiManager) appContext.getApplicationContext()
+				.getSystemService(WIFI_SERVICE);
+		socketFactory = getSocketFactory();
 	}
 
 	@Override
@@ -56,20 +80,60 @@ class AndroidLanTcpPlugin extends LanTcpPlugin {
 		tryToClose(socket);
 	}
 
+	@Override
+	protected Socket createSocket() throws IOException {
+		return socketFactory.createSocket();
+	}
+
+	@Override
+	protected Collection<InetAddress> getLocalIpAddresses() {
+		if (wifiManager == null) return emptyList();
+		WifiInfo info = wifiManager.getConnectionInfo();
+		if (info == null || info.getIpAddress() == 0) return emptyList();
+		return singletonList(intToInetAddress(info.getIpAddress()));
+	}
+
+	private InetAddress intToInetAddress(int ip) {
+		byte[] ipBytes = new byte[4];
+		ipBytes[0] = (byte) (ip & 0xFF);
+		ipBytes[1] = (byte) ((ip >> 8) & 0xFF);
+		ipBytes[2] = (byte) ((ip >> 16) & 0xFF);
+		ipBytes[3] = (byte) ((ip >> 24) & 0xFF);
+		try {
+			return InetAddress.getByAddress(ipBytes);
+		} catch (UnknownHostException e) {
+			// Should only be thrown if address has illegal length
+			throw new AssertionError(e);
+		}
+	}
+
+	// On API 21 and later, a socket that is not created with the wifi
+	// network's socket factory may try to connect via another network
+	private SocketFactory getSocketFactory() {
+		if (SDK_INT < 21) return SocketFactory.getDefault();
+		for (Network net : connectivityManager.getAllNetworks()) {
+			NetworkInfo info = connectivityManager.getNetworkInfo(net);
+			if (info != null && info.getType() == TYPE_WIFI)
+				return net.getSocketFactory();
+		}
+		LOG.warning("Could not find suitable socket factory");
+		return SocketFactory.getDefault();
+	}
+
 	private class NetworkStateReceiver extends BroadcastReceiver {
 
 		@Override
 		public void onReceive(Context ctx, Intent i) {
-			if (!running) return;
+			if (!running || wifiManager == null) return;
-			Object o = ctx.getSystemService(CONNECTIVITY_SERVICE);
+			WifiInfo info = wifiManager.getConnectionInfo();
-			ConnectivityManager cm = (ConnectivityManager) o;
+			if (info == null || info.getIpAddress() == 0) {
-			NetworkInfo net = cm.getActiveNetworkInfo();
+				LOG.info("Not connected to wifi");
-			if (net != null && net.getType() == TYPE_WIFI && net.isConnected()) {
+				socketFactory = SocketFactory.getDefault();
-				LOG.info("Connected to Wi-Fi");
-				if (socket == null || socket.isClosed()) bind();
-			} else {
-				LOG.info("Not connected to Wi-Fi");
 				tryToClose(socket);
+			} else {
+				LOG.info("Connected to wifi");
+				socketFactory = getSocketFactory();
+				if (socket == null || socket.isClosed()) bind();
 			}
 		}
 	}

bramble-core/src/main/java/org/briarproject/bramble/plugin/tcp/LanTcpPlugin.java

@@ -241,10 +241,11 @@ class LanTcpPlugin extends TcpPlugin {
 			}
 			return null;
 		}
-		Socket s = new Socket();
 		try {
 			if (LOG.isLoggable(INFO))
 				LOG.info("Connecting to " + scrubSocketAddress(remote));
+			Socket s = createSocket();
+			s.bind(new InetSocketAddress(socket.getInetAddress(), 0));
 			s.connect(remote);
 			s.setSoTimeout(socketTimeout);
 			if (LOG.isLoggable(INFO))

bramble-core/src/main/java/org/briarproject/bramble/plugin/tcp/TcpPlugin.java

@@ -243,10 +243,11 @@ abstract class TcpPlugin implements DuplexPlugin {
 				}
 				continue;
 			}
-			Socket s = new Socket();
 			try {
 				if (LOG.isLoggable(INFO))
 					LOG.info("Connecting to " + scrubSocketAddress(remote));
+				Socket s = createSocket();
+				s.bind(new InetSocketAddress(socket.getInetAddress(), 0));
 				s.connect(remote);
 				s.setSoTimeout(socketTimeout);
 				if (LOG.isLoggable(INFO))
@@ -261,6 +262,10 @@ abstract class TcpPlugin implements DuplexPlugin {
 		return null;
 	}
 
+	protected Socket createSocket() throws IOException {
+		return new Socket();
+	}
+
 	@Nullable
 	InetSocketAddress parseSocketAddress(String ipPort) {
 		if (StringUtils.isNullOrEmpty(ipPort)) return null;