title: Os permission error when trying to create a `tun` device
body: <p>I'm trying to create a tun device with rust's <code>tun_tap</code> create, I'm following documentation and trying to create an interface with the <code>tun_tap::Iface::new(..);</code>, but I'm getting the error below.</p>
  <pre class="lang-sh prettyprint-override"><code>Error: Os { code: 1, kind: PermissionDenied, message: &quot;Operation not permitted&quot; }
  </code></pre>
  <p>I'm running Ubuntu 20.04 Lts version on this machine,
  How can I run this code without giving it root permission? Is this anything that I can do
  with the code or with Linux permission itself?
  any ideas would be appreciated ;)</p>