Issue 1498 - Look for iptables on the system first

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

Index: src/org/adblockplus/android/configurators/IptablesProxyConfigurator.java
===================================================================
--- a/src/org/adblockplus/android/configurators/IptablesProxyConfigurator.java
+++ b/src/org/adblockplus/android/configurators/IptablesProxyConfigurator.java
@@ -58,14 +58,7 @@
         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();
+      final String path = getIptablesExecutablePath();
 
       RootTools.sendShell("chmod 700 " + path, DEFAULT_TIMEOUT);
 
@@ -103,6 +96,19 @@
     }
   }
 
+  private String getIptablesExecutablePath() throws FileNotFoundException
+  {
+    File iptablesExecutable = new File("/system/bin/iptables");
+    if (!iptablesExecutable.exists())
+    {
+      Log.i(TAG, "iptables not found on the system, using embedded binary");
+      iptablesExecutable = context.getFileStreamPath("iptables");
+    }
+    if (!iptablesExecutable.exists())
+      throw new FileNotFoundException("No iptables executable");
+    return iptablesExecutable.getAbsolutePath();
+  }
+
   @Override
   public boolean registerProxy(final InetAddress address, final int port)
   {