Mask layout with rounded corner xml shape

I have this LinearLayout:

And I want to mask it with rounded corner, like this:

I tried to put it in a FrameLayout with another layout with shape.xml on top of it,

But the most I got was:

or

I'm looking for a way to use shape.xml background,

But with transparent inside the border, and white color outside.

My shape.xml:

<shape
xmlns:android="http://ift.tt/nIICcg"
android:shape="rectangle">
<solid
    android:color="#FFFFFF">
</solid>

<stroke
android:width="2dp"
android:color="#000000" >
</stroke>

<padding
    android:left="5dp"
    android:top="5dp"
    android:right="5dp"
    android:bottom="5dp">
</padding>

<corners
    android:radius="50dp">
</corners>
</shape>