Detect USB tethering on android

you can also use reflection to access the hidden function for setting usb tethering. Here is my code.

    ConnectivityManager cm =
        (ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE);
    Log.d(TAG,"test enable usb tethering");
    String[] available = null;
    int code=-1;
    Method[] wmMethods = cm.getClass().getDeclaredMethods();

    for(Method method: wmMethods){
      if(method.getName().equals("getTetherableIfaces")){
        try {
            available = (String[]) method.invoke(cm);
            break;
        } catch (IllegalArgumentException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            return;
        } catch (IllegalAccessException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            return;
        } catch (InvocationTargetException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            return;
        }
      }
    }

    for(Method method: wmMethods){
          if(method.getName().equals("tether")){                  
              try {
                code = (Integer) method.invoke(cm, available[0]);


            } catch (IllegalArgumentException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
                return;
            } catch (IllegalAccessException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
                return;
            } catch (InvocationTargetException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
                return;
            }
            break;
          }
    }

    if (code==0) 
        Log.d(TAG,"Enable usb tethering successfully!");
    else
        Log.d(TAG,"Enable usb tethering failed!");

For disabling usb tethering, you just need to change the reflection method name "getTetherableIfaces" to "getTetheredIfaces", change "tether" to "untether".

Please check.

Looking through the Settings.System documentation points to the answer being no, its not possible to do this.

Link to said documentation

This should work on all phones, confirmed on some Android 7,6 and 5 devices;

Method: interface rndisX (typically rndis0) only shows up when usb tethering is enabled.

Code Example:

private static boolean isTetheringActive(Context context){
    try{
        for(Enumeration<NetworkInterface> en = NetworkInterface.getNetworkInterfaces(); en.hasMoreElements();){
            NetworkInterface intf=en.nextElement();
            for(Enumeration<InetAddress> enumIpAddr = intf.getInetAddresses(); enumIpAddr.hasMoreElements();){
                InetAddress inetAddress=enumIpAddr.nextElement();
                if(!intf.isLoopback()){
                    if(intf.getName().contains("rndis")){
                        return true;
                    }
                }
            }
        }
    }catch(Exception e){e.printStackTrace();}
    return false;
}