I want to run a VPN software inside an lxc guest, but the required TUN/TAP device (/dev/net/tun) is missing in the container. Anyone knows how to enable this device ? Here is the definition XML:

<domain type="lxc">
  <name>centos</name>
  <memory unit="MiB">1024</memory>
  <os>
    <type>exe</type>
    <init>/sbin/init</init>
  </os>
  <devices>
    <console type="pty"/>
    <filesystem type="mount">
      <source dir="/virsh/centos"/>
      <target dir="/"/>
    </filesystem>
    <interface type="bridge">
      <source bridge="br0"/>
      <model type="virtio"/>
    </interface>
  </devices>
</domain>