Network support with VPNKit
===========================

The simulation can be configured to use VPNKit to provide network support.
While this was developed for macOS, it should work on other platforms
as well.

Configuration
-------------

.. code-block:: bash

    CONFIG_SIM_NETDEV=y
    CONFIG_SIM_NETDEV_TAP is not set
    CONFIG_SIM_NETDEV_VPNKIT=y
    CONFIG_SIM_NETDEV_VPNKIT_PATH="/tmp/vpnkit-nuttx"

You can use the ``sim:vpnkit`` configuration, which includes the above
settings.

.. code-block:: bash

    ./tools/configure.sh sim:vpnkit

VPNKit setup
------------

See `https://github.com/moby/vpnkit` for build instructions.

If you have Docker Desktop for Mac installed on your machine,
you can find a vpnkit binary at:

.. code-block:: bash

    /Applications/Docker.app/Contents/Resources/bin/com.docker.vpnkit

A docker image containing a static Linux binary is also available:

`https://hub.docker.com/r/djs55/vpnkit`

How to run
----------

You can use it as the following:

.. code-block:: bash

    % vpnkit --ethernet /tmp/vpnkit-nuttx &
    % ./nuttx

NuttX's ``CONFIG_SIM_NETDEV_VPNKIT_PATH`` should match vpnkit's
``--ethernet`` option.