Proxy configurators

src/org/adblockplus/android/configurators/IptablesProxyConfigurator.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.io.File;
+import java.io.FileNotFoundException;
+import java.net.InetAddress;
+import java.util.List;
+
+import org.adblockplus.android.Utils;
+
+import com.stericson.RootTools.RootTools;
+
+import android.content.Context;
+import android.util.Log;
+
+/**
+ * Proxy registration using RootTools and iptables.
+ */
+public class IptablesProxyConfigurator implements ProxyConfigurator
+{
+  private static final String TAG = Utils.getTag(IptablesProxyConfigurator.class);
+  private static final int DEFAULT_TIMEOUT = 3000;
+  private static final String IPTABLES_RETURN = " -t nat -m owner --uid-owner {{UID}} -A OUTPUT -p tcp -j RETURN\n";
+  private static final String IPTABLES_ADD_HTTP = " -t nat -A OUTPUT -p tcp --dport 80 -j REDIRECT --to {{PORT}}\n";
+
+  private final Context context;
+  private String iptables;
+  private boolean isRegistered = false;
+
+  public IptablesProxyConfigurator(final Context context)
+  {
+    this.context = context;
+  }
+
+  @Override
+  public boolean initialize()
+  {
+    try
+    {
+      if (!RootTools.isAccessGiven())
+      {
+        throw new IllegalStateException("No root access");
+      }
+
+      final File ipt = this.context.getFileStreamPath("iptables");
+
+      if (!ipt.exists())
+      {
+        throw new FileNotFoundException("No iptables executable");
+      }
+
+      final String path = ipt.getAbsolutePath();
+
+      RootTools.sendShell("chmod 700 " + path, DEFAULT_TIMEOUT);
+
+      boolean compatible = false;
+      boolean version = false;
+
+      final String command = path + " --version\n" + path + " -L -t nat -n\n";
+
+      final List<String> result = RootTools.sendShell(command, DEFAULT_TIMEOUT);
+
+      for (final String line : result)
+      {
+        if (line.contains("OUTPUT"))
+        {
+          compatible = true;
+        }
+        if (line.contains("v1.4."))
+        {
+          version = true;
+        }
+      }
+
+      if (!(compatible && version))
+      {
+        throw new IllegalStateException("Incompatible iptables excutable");
+      }
+
+      this.iptables = path;
+
+      return true;
+    }
+    catch (final Exception e)
+    {
+      return false;
+    }
+  }
+
+  @Override
+  public boolean registerProxy(final InetAddress address, final int port)
+  {
+    try
+    {
+      final int uid = this.context.getPackageManager().getPackageInfo(this.context.getPackageName(), 0).applicationInfo.uid;
+
+      final StringBuilder cmd = new StringBuilder();
+      cmd.append(this.iptables);
+      cmd.append(IPTABLES_RETURN.replace("{{UID}}", String.valueOf(uid)));
+      cmd.append('\n');
+      cmd.append(this.iptables);
+      cmd.append(IPTABLES_ADD_HTTP.replace("{{PORT}}", String.valueOf(port)));
+
+      RootTools.sendShell(cmd.toString(), DEFAULT_TIMEOUT);
+
+      this.isRegistered = true;
+
+      return true;
+    }
+    catch (final Exception e)
+    {
+      // I leave this logging message for now, passing 'init' and failing 'register' definitely is a failure
+      Log.e(TAG, "Couldn't register proxy using iptables.", e);
+      return false;
+    }
+  }
+
+  @Override
+  public void unregisterProxy()
+  {
+    try
+    {
+      RootTools.sendShell(this.iptables + " -t nat -F OUTPUT", DEFAULT_TIMEOUT);
+    }
+    catch (final Exception e)
+    {
+      Log.w(TAG, "Failed to unregister proxy using iptables.", e);
+    }
+    finally
+    {
+      this.isRegistered = false;
+    }
+  }
+
+  @Override
+  public void shutdown()
+  {
+    // Nothing to do here
+  }
+
+  public static List<String> getIptablesOutput(final Context context)
+  {
+    try
+    {
+      if (!RootTools.isAccessGiven())
+      {
+        throw new IllegalStateException("No root access");
+      }
+
+      final File ipt = context.getFileStreamPath("iptables");
+
+      if (!ipt.exists())
+      {
+        throw new FileNotFoundException("No iptables executable");
+      }
+
+      final 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";
+
+      final List<String> result = RootTools.sendShell(command, DEFAULT_TIMEOUT);
+
+      for (final String line : result)
+      {
+        if (line.contains("OUTPUT"))
+        {
+          compatible = true;
+        }
+        if (line.contains("v1.4."))
+        {
+          version = true;
+        }
+      }
+
+      if (!(compatible && version))
+      {
+        throw new IllegalStateException("Incompatible iptables excutable");
+      }
+
+      command = path + " -L -t nat -n\n";
+
+      return RootTools.sendShell(command, DEFAULT_TIMEOUT);
+    }
+    catch (final Throwable t)
+    {
+      return null;
+    }
+  }
+
+  @Override
+  public ProxyRegistrationType getType()
+  {
+    return ProxyRegistrationType.IPTABLES;
+  }
+
+  @Override
+  public boolean isRegistered()
+  {
+    return this.isRegistered;
+  }
+
+  @Override
+  public boolean isSticky()
+  {
+    return false;
+  }
+
+  @Override
+  public String toString()
+  {
+    return "[ProxyConfigurator: " + this.getType() + "]";
+  }
+}