Proxy configurators

src/org/adblockplus/android/configurators/NativeProxyConfigurator.java

+/*
+ * This file is part of Adblock Plus <http://adblockplus.org/>,
+ * Copyright (C) 2006-2014 Eyeo GmbH
+ *
+ * Adblock Plus is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 3 as
+ * published by the Free Software Foundation.
+ *
+ * Adblock Plus is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package org.adblockplus.android.configurators;
+
+import java.net.InetAddress;
+
+import org.adblockplus.android.compat.CompatibilityException;
+import org.adblockplus.android.compat.LinkProperties;
+import org.adblockplus.android.compat.ProxyProperties;
+
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+import android.content.IntentFilter;
+import android.net.ConnectivityManager;
+import android.net.NetworkInfo;
+import android.os.Parcelable;
+
+/**
+ * Proxy registrator setting native proxy using {@code android.net.LinkProperties} via reflection.
+ */
+public class NativeProxyConfigurator implements ProxyConfigurator
+{
+  private final Context context;
+  private final WiFiChangeReceiver wiFiChangeReceiver;
+  private ProxyProperties proxyProperties;
+  private boolean isRegistered = false;
+
+  public NativeProxyConfigurator(final Context context)
+  {
+    this.context = context;
+    this.wiFiChangeReceiver = new WiFiChangeReceiver(this);
+  }
+
+  /**
+   * Reliably checks for setHttpProxy hack using {@code android.net.wifi.LINK_CONFIGURATION_CHANGED}.
+   *
+   * @param context
+   *          The context used for querying the {@code ConnectivityManager}
+   * @return {@code true} if we can set a WiFi proxy using this method
+   */
+  public static boolean canUse(final Context context)
+  {
+    try
+    {
+      final ConnectivityManager conMan = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
+      final NetworkInfo ni = conMan.getActiveNetworkInfo();
+
+      final Object lp;
+
+      // Check if we're currently running on WiFi
+      if (ni != null && ni.getType() == ConnectivityManager.TYPE_WIFI)
+      {
+        // I'm using reflection directly here to keep this method self-contained.
+        lp = conMan.getClass()
+            .getMethod("getActiveLinkProperties")
+            .invoke(conMan);
+      }
+      else
+      // We're not running on WiFi so get the last used WiFi link properties
+      {
+        // I'm using reflection directly here to keep this method self-contained.
+        lp = conMan.getClass()
+            .getMethod("getLinkProperties", int.class)
+            .invoke(conMan, ConnectivityManager.TYPE_WIFI);
+      }
+
+      if (lp == null)
+      {
+        // Is this even possible?
+        throw new IllegalStateException("No WiFi?");
+      }
+
+      context.sendBroadcast(
+          new Intent("android.net.wifi.LINK_CONFIGURATION_CHANGED")
+              .putExtra("linkProperties", (Parcelable) lp));
+    }
+    catch (final Throwable t)
+    {
+      return false;
+    }
+
+    return true;
+  }
+
+  @Override
+  public boolean initialize()
+  {
+    if (canUse(this.context))
+    {
+      this.context.registerReceiver(this.wiFiChangeReceiver, new IntentFilter(ConnectivityManager.CONNECTIVITY_ACTION));
+      return true;
+    }
+
+    return false;
+  }
+
+  private boolean sendIntent(final LinkProperties lp, final ProxyProperties proxyProperties)
+  {
+    boolean success = true;
+
+    final ConnectivityManager conMan = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
+    final NetworkInfo ni = conMan.getActiveNetworkInfo();
+
+    if (ni != null && ni.getType() == ConnectivityManager.TYPE_WIFI)
+    {
+      final Intent intent = new Intent("android.net.wifi.LINK_CONFIGURATION_CHANGED");
+
+      if (lp.isValid())
+      {
+        try
+        {
+          lp.setHttpProxy(proxyProperties);
+          intent.putExtra("linkProperties", (Parcelable) lp.getLinkProperties());
+          context.sendBroadcast(intent);
+        }
+        catch (final Exception e)
+        {
+          // Catch all, again
+          success = false;
+        }
+      }
+    }
+
+    return success;
+  }
+
+  private boolean registerProxy(final ProxyProperties proxyProperties)
+  {
+    try
+    {
+      final ConnectivityManager conMan = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
+
+      return this.sendIntent(LinkProperties.getActiveLinkProperties(conMan), proxyProperties);
+    }
+    catch (final CompatibilityException e)
+    {
+      return false;
+    }
+  }
+
+  private boolean reRegisterProxy()
+  {
+    return this.registerProxy(this.proxyProperties);
+  }
+
+  @Override
+  public boolean registerProxy(final InetAddress address, final int port)
+  {
+    this.proxyProperties = new ProxyProperties(address.getHostName(), port, "");
+
+    return this.isRegistered = this.registerProxy(this.proxyProperties);
+  }
+
+  @Override
+  public void unregisterProxy()
+  {
+    this.proxyProperties = null;
+    this.isRegistered = false;
+    this.registerProxy(this.proxyProperties);
+  }
+
+  @Override
+  public void shutdown()
+  {
+    this.context.unregisterReceiver(this.wiFiChangeReceiver);
+  }
+
+  @Override
+  public ProxyRegistrationType getType()
+  {
+    return ProxyRegistrationType.NATIVE;
+  }
+
+  @Override
+  public boolean isRegistered()
+  {
+    return this.isRegistered;
+  }
+
+  @Override
+  public boolean isSticky()
+  {
+    return false;
+  }
+
+  @Override
+  public String toString()
+  {
+    return "[ProxyConfigurator: " + this.getType() + "]";
+  }
+
+  private final static class WiFiChangeReceiver extends BroadcastReceiver
+  {
+    private final NativeProxyConfigurator configurator;
+
+    private WiFiChangeReceiver(final NativeProxyConfigurator configurator)
+    {
+      this.configurator = configurator;
+    }
+
+    @Override
+    public void onReceive(final Context context, final Intent intent)
+    {
+      if (ConnectivityManager.CONNECTIVITY_ACTION.equals(intent.getAction()))
+      {
+        final ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
+        final NetworkInfo ni = connectivityManager.getActiveNetworkInfo();
+
+        if (ni != null && ni.getType() == ConnectivityManager.TYPE_WIFI && ni.isAvailable() && ni.isConnected())
+        {
+          this.configurator.reRegisterProxy();
+        }
+      }
+    }
+  }
+}