ABP/Android proxy service

src/org/adblockplus/android/ProxyService.java

Index: src/org/adblockplus/android/ProxyService.java
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+package org.adblockplus.android;
+
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.lang.reflect.Method;
+import java.net.InetAddress;
+import java.net.ServerSocket;
+import java.util.List;
+import java.util.Properties;
+import java.util.concurrent.TimeoutException;
+
+import sunlabs.brazil.server.Server;
+import sunlabs.brazil.util.Base64;
+import android.app.Notification;
+import android.app.NotificationManager;
+import android.app.PendingIntent;
+import android.app.Service;
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+import android.content.IntentFilter;
+import android.content.SharedPreferences;
+import android.content.SharedPreferences.OnSharedPreferenceChangeListener;
+import android.content.pm.PackageManager.NameNotFoundException;
+import android.net.ConnectivityManager;
+import android.net.NetworkInfo;
+import android.os.Binder;
+import android.os.Build;
+import android.os.Handler;
+import android.os.IBinder;
+import android.preference.PreferenceManager;
+import android.util.Log;
+import android.widget.Toast;
+
+import com.stericson.RootTools.RootTools;
+import com.stericson.RootTools.RootToolsException;
+
+public class ProxyService extends Service implements OnSharedPreferenceChangeListener
+{
+  private static final String LOCALHOST = "127.0.0.1";
+  /**
+   * Indicates that system supports native proxy configuration.
+   */
+  public static boolean hasNativeProxy = Build.VERSION.SDK_INT >= 12; // Honeycomb 3.1
+
+  static
+  {
+    RootTools.debugMode = false;
+  }
+
+  private static final String TAG = "ProxyService";
+  private static final boolean logRequests = false;
+
+  private final static int DEFAULT_TIMEOUT = 3000;
+  private final static int NO_TRAFFIC_TIMEOUT = 5 * 60 * 1000; // 5 minutes
+
+  final static int ONGOING_NOTIFICATION_ID = R.string.app_name;
+  private final static int NOTRAFFIC_NOTIFICATION_ID = R.string.app_name + 3;
+
+  /**
+   * Broadcasted when service starts or stops.
+   */
+  public final static String BROADCAST_STATE_CHANGED = "org.adblockplus.android.service.state";
+  /**
+   * Broadcasted if proxy fails to start.
+   */
+  public final static String BROADCAST_PROXY_FAILED = "org.adblockplus.android.proxy.failure";
+
+  private final static String IPTABLES_RETURN = " -t nat -m owner --uid-owner {{UID}} -A OUTPUT -p tcp -j RETURN\n";
+  private final static String IPTABLES_ADD_HTTP = " -t nat -A OUTPUT -p tcp --dport 80 -j REDIRECT --to {{PORT}}\n";
+
+  private Notification ongoingNotification;
+  private PendingIntent contentIntent;
+
+  private Handler notrafficHandler;
+
+  protected ProxyServer proxy = null;
+  protected int port;
+
+  /**
+   * Indicates that service is working with root privileges.
+   */
+  private boolean transparent = false;
+  /**
+   * Indicates that service has autoconfigured Android proxy settings (version
+   * 3.1+).
+   */
+  private boolean nativeProxy = false;
+
+  private String iptables = null;
+
+  @Override
+  public void onCreate()
+  {
+    super.onCreate();
+
+    // Get port for local proxy
+    SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
+    String p = prefs.getString(getString(R.string.pref_port), null);
+    try
+    {
+      port = p != null ? Integer.valueOf(p) : getResources().getInteger(R.integer.def_port);
+    }
+    catch (NumberFormatException e)
+    {
+      Toast.makeText(this, getString(R.string.msg_badport) + ": " + p, Toast.LENGTH_LONG).show();
+      port = getResources().getInteger(R.integer.def_port);
+    }
+
+    // Try to read user proxy settings
+    String proxyHost = null;
+    String proxyPort = null;
+    String proxyExcl = null;
+    String proxyUser = null;
+    String proxyPass = null;
+
+    if (hasNativeProxy)
+    {
+      // Read system settings
+      proxyHost = System.getProperty("http.proxyHost");
+      proxyPort = System.getProperty("http.proxyPort");
+      proxyExcl = System.getProperty("http.nonProxyHosts");
+
+      Log.d(TAG, "PRX: " + proxyHost + ":" + proxyPort + "(" + proxyExcl + ")");
+      String[] px = ProxySettings.getUserProxy(getApplicationContext()); // not used but left for future reference
+      if (px != null)
+        Log.d(TAG, "PRX: " + px[0] + ":" + px[1] + "(" + px[2] + ")");
+    }
+    else
+    {
+      // Read application settings
+      proxyHost = prefs.getString(getString(R.string.pref_proxyhost), null);
+      proxyPort = prefs.getString(getString(R.string.pref_proxyport), null);
+      proxyUser = prefs.getString(getString(R.string.pref_proxyuser), null);
+      proxyPass = prefs.getString(getString(R.string.pref_proxypass), null);
+    }
+
+    // Check for root privileges and try to install transparent proxy
+    if (RootTools.isAccessGiven())
+    {
+      try
+      {
+        initIptables();
+
+        StringBuffer cmd = new StringBuffer();
+        int uid = getPackageManager().getPackageInfo(getPackageName(), 0).applicationInfo.uid;
+        cmd.append(iptables);
+        cmd.append(IPTABLES_RETURN.replace("{{UID}}", String.valueOf(uid)));
+        cmd.append(iptables);
+        cmd.append(IPTABLES_ADD_HTTP.replace("{{PORT}}", String.valueOf(port)));
+        String rules = cmd.toString();
+        RootTools.sendShell(rules, DEFAULT_TIMEOUT);
+        transparent = true;
+      }
+      catch (FileNotFoundException e)
+      {
+        // ignore - this is "normal" case
+      }
+      catch (NameNotFoundException e)
+      {
+        Log.e(TAG, "Failed to initialize iptables", e);
+      }
+      catch (IOException e)
+      {
+        Log.e(TAG, "Failed to initialize iptables", e);
+      }
+      catch (RootToolsException e)
+      {
+        Log.e(TAG, "Failed to initialize iptables", e);
+      }
+      catch (TimeoutException e)
+      {
+        Log.e(TAG, "Failed to initialize iptables", e);
+      }
+    }
+
+    if (!transparent)
+    {
+      // Try to set native proxy
+      nativeProxy = ProxySettings.setConnectionProxy(getApplicationContext(), LOCALHOST, port, "");
+
+      if (nativeProxy)
+      {
+        registerReceiver(connectionReceiver, new IntentFilter(ConnectivityManager.CONNECTIVITY_ACTION));
+        registerReceiver(connectionReceiver, new IntentFilter("android.net.wifi.LINK_CONFIGURATION_CHANGED"));
+      }
+    }
+
+    // Start engine
+    AdblockPlus.getApplication().startEngine();
+
+    registerReceiver(proxyReceiver, new IntentFilter(ProxyService.BROADCAST_PROXY_FAILED));
+    registerReceiver(matchesReceiver, new IntentFilter(AdblockPlus.BROADCAST_FILTER_MATCHES));
+
+    // Start proxy
+    if (proxy == null)
+    {
+      ServerSocket listen = null;
+      try
+      {
+        // TODO Add port travel
+        listen = new ServerSocket(port, 1024);
+      }
+      catch (IOException e)
+      {
+        sendBroadcast(new Intent(BROADCAST_PROXY_FAILED).putExtra("msg", e.getMessage()));
+        Log.e(TAG, null, e);
+        return;
+      }
+
+      Properties config = new Properties();
+      config.put("handler", "main");
+      config.put("main.prefix", "");
+      config.put("main.class", "sunlabs.brazil.server.ChainHandler");
+      if (transparent)
+      {
+        config.put("main.handlers", "urlmodifier adblock");
+        config.put("urlmodifier.class", "org.adblockplus.brazil.TransparentProxyHandler");
+      }
+      else
+      {
+        config.put("main.handlers", "https adblock");
+        config.put("https.class", "org.adblockplus.brazil.SSLConnectionHandler");
+      }
+      config.put("adblock.class", "org.adblockplus.brazil.RequestHandler");
+      if (logRequests)
+        config.put("adblock.proxylog", "yes");
+
+      configureUserProxy(config, proxyHost, proxyPort, proxyExcl, proxyUser, proxyPass);
+
+      proxy = new ProxyServer();
+      proxy.logLevel = Server.LOG_DIAGNOSTIC;
+      proxy.setup(listen, config.getProperty("handler"), config);
+      proxy.start();
+    }
+
+    prefs.registerOnSharedPreferenceChangeListener(this);
+
+    String msg = getString(transparent ? R.string.notif_all : nativeProxy ? R.string.notif_wifi : R.string.notif_waiting);
+    if (!transparent && !nativeProxy)
+    {
+      // Initiate no traffic check
+      notrafficHandler = new Handler();
+      notrafficHandler.postDelayed(noTraffic, NO_TRAFFIC_TIMEOUT);
+    }
+    // Lock service
+    ongoingNotification = new Notification();
+    ongoingNotification.when = 0;
+    contentIntent = PendingIntent.getActivity(this, 0, new Intent(this, Preferences.class).addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_NEW_TASK), 0);
+    ongoingNotification.icon = R.drawable.ic_stat_blocking;
+    ongoingNotification.setLatestEventInfo(getApplicationContext(), getText(R.string.app_name), msg, contentIntent);
+    startForeground(ONGOING_NOTIFICATION_ID, ongoingNotification);
+
+    sendBroadcast(new Intent(BROADCAST_STATE_CHANGED).putExtra("enabled", true).putExtra("port", port).putExtra("manual", !transparent && !nativeProxy));
+    Log.i(TAG, "Service started");
+  }
+
+  @Override
+  public void onDestroy()
+  {
+    super.onDestroy();
+
+    stopNoTrafficCheck(false);
+
+    unregisterReceiver(matchesReceiver);
+    unregisterReceiver(proxyReceiver);
+
+    // Stop IP redirecting
+    if (transparent)
+    {
+      new Thread() {
+        @Override
+        public void run()
+        {
+          try
+          {
+            RootTools.sendShell(iptables + " -t nat -F OUTPUT", DEFAULT_TIMEOUT);
+          }
+          catch (Exception e)
+          {
+            Log.e(TAG, "Failed to clear iptables", e);
+          }
+        }
+      }.start();
+    }
+
+    // Clear native proxy
+    if (nativeProxy)
+    {
+      unregisterReceiver(connectionReceiver);
+      clearConnectionProxy();
+    }
+
+    sendBroadcast(new Intent(BROADCAST_STATE_CHANGED).putExtra("enabled", false));
+
+    // Stop proxy server
+    proxy.close();
+
+    // Stop engine if not in interactive mode
+    AdblockPlus.getApplication().stopEngine(false);
+
+    // Release service lock
+    stopForeground(true);
+
+    Log.i(TAG, "Service stopped");
+  }
+
+  /**
+   * Restores system proxy settings via native call on Android 3.1+ devices using
+   * Java reflection.
+   */
+  private void clearConnectionProxy()
+  {
+    String proxyHost = (String) proxy.props.getProperty("adblock.proxyHost");
+    String proxyPort = (String) proxy.props.getProperty("adblock.proxyPort");
+    String proxyExcl = (String) proxy.props.getProperty("adblock.proxyExcl");
+    int port = 0;
+    try
+    {
+      if (proxyHost != null)
+        port = Integer.valueOf(proxyPort);
+    }
+    catch (NumberFormatException e)
+    {
+      Log.e(TAG, "Bad port setting", e);
+    }
+    ProxySettings.setConnectionProxy(getApplicationContext(), proxyHost, port, proxyExcl);
+  }
+
+  /**
+   * Sets user proxy settings in proxy service properties.
+   */
+  private void configureUserProxy(Properties config, String proxyHost, String proxyPort, String proxyExcl, String proxyUser, String proxyPass)
+  {
+    // Clean previous settings
+    config.remove("adblock.proxyHost");
+    config.remove("adblock.proxyPort");
+    config.remove("adblock.auth");
+    config.remove("adblock.proxyExcl");
+    if (!transparent)
+    {
+      config.remove("https.proxyHost");
+      config.remove("https.proxyPort");
+      config.remove("https.auth");
+    }
+
+    if (nativeProxy)
+      passProxySettings(proxyHost, proxyPort, proxyExcl);
+
+    // Check if there are any settings
+    if (proxyHost == null || "".equals(proxyHost))
+      return;
+
+    // Check for dirty proxy settings - this indicated previous crash:
+    // proxy points to ourselves
+    // proxy port is null, 0 or not a number
+    // proxy is 127.0.0.1:8080
+    if (proxyPort == null)
+      return;
+    int p = 0;
+    try
+    {
+      p = Integer.valueOf(proxyPort);
+    }
+    catch (NumberFormatException e)
+    {
+      return;
+    }
+    if (p == 0 || isLocalHost(proxyHost) && (p == port || p == 8080))
+    {
+      if (nativeProxy)
+        passProxySettings(null, null, null);
+      return;
+    }
+
+    config.put("adblock.proxyHost", proxyHost);
+    config.put("adblock.proxyPort", proxyPort);
+    if (!transparent)
+    {
+      config.put("https.proxyHost", proxyHost);
+      config.put("https.proxyPort", proxyPort);
+    }
+
+    // TODO Not implemented in our proxy but needed to restore settings
+    if (proxyExcl != null)
+      config.put("adblock.proxyExcl", proxyExcl);
+
+    if (proxyUser != null && !"".equals(proxyUser) && proxyPass != null && !"".equals(proxyPass))
+    {
+      // Base64 encode user:password
+      String proxyAuth = "Basic " + new String(Base64.encode(proxyUser + ":" + proxyPass));
+      config.put("adblock.auth", proxyAuth);
+      if (!transparent)
+        config.put("https.auth", proxyAuth);
+    }
+  }
+
+  private void passProxySettings(String proxyHost, String proxyPort, String proxyExcl)
+  {
+    try
+    {
+      CrashHandler handler = (CrashHandler) Thread.getDefaultUncaughtExceptionHandler();
+      handler.saveProxySettings(proxyHost, proxyPort, proxyExcl);
+    }
+    catch (ClassCastException e)
+    {
+      // ignore - default handler in use
+    }
+  }
+
+  @Override
+  public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key)
+  {
+    if (hasNativeProxy)
+    {
+      String ketHost = getString(R.string.pref_proxyhost);
+      String keyPort = getString(R.string.pref_proxyport);
+      String keyUser = getString(R.string.pref_proxyuser);
+      String keyPass = getString(R.string.pref_proxypass);
+      if (key.equals(ketHost) || key.equals(keyPort) || key.equals(keyUser) || key.equals(keyPass))
+      {
+        String proxyHost = sharedPreferences.getString(ketHost, null);
+        String proxyPort = sharedPreferences.getString(keyPort, null);
+        String proxyUser = sharedPreferences.getString(keyUser, null);
+        String proxyPass = sharedPreferences.getString(keyPass, null);
+        if (proxy != null)
+        {
+          configureUserProxy(proxy.props, proxyHost, proxyPort, null, proxyUser, proxyPass);
+          proxy.restart(proxy.props.getProperty("handler"));
+        }
+      }
+    }
+  }
+
+  public boolean isTransparent()
+  {
+    return transparent;
+  }
+
+  public boolean isNativeProxy()
+  {
+    return nativeProxy;
+  }
+
+  /**
+   * Checks if specified host is local.
+   */
+  private static final boolean isLocalHost(String host)
+  {
+    if (host == null)
+      return false;
+
+    try
+    {
+      if (host.equalsIgnoreCase("localhost"))
+        return true;
+
+      String className = "android.net.NetworkUtils";
+      Class<?> c = Class.forName(className);
+      /*
+       * InetAddress address = NetworkUtils.numericToInetAddress(host);
+       */
+      Method method = c.getMethod("numericToInetAddress", String.class);
+      InetAddress address = (InetAddress) method.invoke(null, host);
+
+      if (address.isLoopbackAddress())
+        return true;
+    }
+    catch (Exception e)
+    {
+      Log.w(TAG, null, e);
+    }
+    return false;
+  }
+
+  /**
+   * Initializes iptables executable.
+   * 
+   * @throws FileNotFoundException If iptables initialization failed due to provided reasons.
+   */
+  private void initIptables() throws IOException, RootToolsException, TimeoutException, FileNotFoundException
+  {
+    if (!RootTools.isAccessGiven())
+      throw new FileNotFoundException("No root access");
+
+    File ipt = getFileStreamPath("iptables");
+
+    if (!ipt.exists())
+    {
+      Log.e(TAG, "No iptables excutable found");
+      throw new FileNotFoundException("No iptables executable");
+    }
+    
+    String path = ipt.getAbsolutePath();
+
+    RootTools.sendShell("chmod 700 " + path, DEFAULT_TIMEOUT);
+
+    boolean compatible = false;
+    boolean version = false;
+
+    String command = path + " --version\n" + path + " -L -t nat -n\n";
+
+    List<String> result = RootTools.sendShell(command, DEFAULT_TIMEOUT);
+    for (String line : result)
+    {
+      if (line.contains("OUTPUT"))
+        compatible = true;
+      if (line.contains("v1.4."))
+        version = true;
+    }
+
+    if (!compatible || !version)
+    {
+      Log.e(TAG, "Incompatible iptables excutable");
+      throw new FileNotFoundException("Incompatible iptables excutable");
+    }
+
+    iptables = path;
+  }
+  
+  public List<String> getIptablesOutput()
+  {
+    if (iptables == null)
+      return null;
+
+    String command = iptables + " -L -t nat -n\n";
+    try
+    {
+      return RootTools.sendShell(command, DEFAULT_TIMEOUT);
+    }
+    catch (Exception e)
+    {
+      Log.e(TAG, "Failed to get iptables configuration", e);
+      return null;
+    }
+  }
+
+  /**
+   * Stops no traffic check, optionally resetting notification message.
+   * 
+   * @param changeStatus
+   *          true if notification message should be set to normal operating
+   *          mode
+   */
+  private void stopNoTrafficCheck(boolean changeStatus)
+  {
+    if (notrafficHandler != null)
+    {
+      notrafficHandler.removeCallbacks(noTraffic);
+      if (changeStatus)
+      {
+        NotificationManager notificationManager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
+        ongoingNotification.setLatestEventInfo(ProxyService.this, getText(R.string.app_name), getText(R.string.notif_wifi), contentIntent);
+        notificationManager.notify(ONGOING_NOTIFICATION_ID, ongoingNotification);
+      }
+    }
+    notrafficHandler = null;
+  }
+
+  private final IBinder binder = new LocalBinder();
+
+  public final class LocalBinder extends Binder
+  {
+    public ProxyService getService()
+    {
+      return ProxyService.this;
+    }
+  }
+
+  @Override
+  public IBinder onBind(Intent intent)
+  {
+    return binder;
+  }
+
+  /**
+   * Executed if no traffic is detected after a period of time. Notifies user
+   * about possible configuration problems.
+   */
+  private Runnable noTraffic = new Runnable() {
+    public void run()
+    {
+      // Show warning notification
+      Notification notification = new Notification();
+      notification.icon = R.drawable.ic_stat_warning;
+      notification.when = System.currentTimeMillis();
+      notification.flags |= Notification.FLAG_AUTO_CANCEL;
+      notification.defaults |= Notification.DEFAULT_SOUND;
+      Intent intent = new Intent(ProxyService.this, ConfigurationActivity.class).addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
+      intent.putExtra("port", port);
+      PendingIntent contentIntent = PendingIntent.getActivity(ProxyService.this, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT);
+      notification.setLatestEventInfo(ProxyService.this, getText(R.string.app_name), getString(R.string.notif_notraffic), contentIntent);
+      NotificationManager notificationManager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
+      notificationManager.notify(NOTRAFFIC_NOTIFICATION_ID, notification);
+    }
+  };
+
+  /**
+   * Stops no traffic check if traffic is detected by proxy service.
+   */
+  private BroadcastReceiver matchesReceiver = new BroadcastReceiver() {
+    @Override
+    public void onReceive(final Context context, Intent intent)
+    {
+      if (intent.getAction().equals(AdblockPlus.BROADCAST_FILTER_MATCHES))
+        stopNoTrafficCheck(true);
+    }
+  };
+
+  /**
+   * Stops service if proxy fails.
+   */
+  private BroadcastReceiver proxyReceiver = new BroadcastReceiver() {
+    @Override
+    public void onReceive(final Context context, Intent intent)
+    {
+      if (intent.getAction().equals(ProxyService.BROADCAST_PROXY_FAILED))
+      {
+        stopSelf();
+      }
+    }
+  };
+
+  /**
+   * Monitors system network connection settings changes and updates proxy
+   * settings accordingly.
+   */
+  private BroadcastReceiver connectionReceiver = new BroadcastReceiver() {
+    @Override
+    public void onReceive(Context ctx, Intent intent)
+    {
+      String action = intent.getAction();
+      Log.i(TAG, "Action: " + action);
+      if (ConnectivityManager.CONNECTIVITY_ACTION.equals(action))
+      {
+        NetworkInfo info = intent.getParcelableExtra(ConnectivityManager.EXTRA_NETWORK_INFO);
+        String typeName = info.getTypeName();
+        String subtypeName = info.getSubtypeName();
+        boolean available = info.isAvailable();
+        Log.i(TAG, "Network Type: " + typeName + ", subtype: " + subtypeName + ", available: " + available);
+        if (info.getType() == ConnectivityManager.TYPE_WIFI)
+          ProxySettings.setConnectionProxy(getApplicationContext(), LOCALHOST, port, "");
+      }
+      else if ("android.net.wifi.LINK_CONFIGURATION_CHANGED".equals(action))
+      {
+        Object lp = intent.getParcelableExtra("linkProperties");
+        Method method;
+        try
+        {
+          /*
+           * lp.getHttpProxy();
+           */
+          method = lp.getClass().getMethod("getHttpProxy");
+          Object pp = method.invoke(lp);
+
+          String[] userProxy = ProxySettings.getUserProxy(pp);
+          if (userProxy != null && Integer.valueOf(userProxy[1]) != port)
+          {
+            Log.i(TAG, "User has set new proxy: " + userProxy[0] + ":" + userProxy[1] + "(" + userProxy[2] + ")");
+            if (proxy != null)
+            {
+              configureUserProxy(proxy.props, userProxy[0], userProxy[1], userProxy[2], null, null);
+              proxy.restart(proxy.props.getProperty("handler"));
+            }
+          }
+        }
+        catch (Exception e)
+        {
+          // This should not happen
+          Log.e(TAG, null, e);
+        }
+
+      }
+    }
+  };
+
+  final class ProxyServer extends Server
+  {
+    @Override
+    public void close()
+    {
+      try
+      {
+        listen.close();
+        this.interrupt();
+        this.join();
+      }
+      catch (Exception e)
+      {
+        // ignore - it always happens
+      }
+      log(LOG_WARNING, null, "server stopped");
+    }
+
+    @Override
+    public void log(int level, Object obj, String message)
+    {
+      if (level <= logLevel)
+      {
+        Log.println(7 - level, obj != null ? obj.toString() : TAG, message);
+      }
+    }
+  }
+}