Re: [RFC v2] net: introduce OpenVPN Data Channel Offload (ovpn-dco)

From: Stephen Hemminger
Date: Fri Aug 12 2022 - 14:44:37 EST


On Fri, 12 Aug 2022 21:34:33 +0300
Sergey Ryazanov <ryazanov.s.a@xxxxxxxxx> wrote:

> What is the purpose of creating and destroying interfaces via RTNL,
> but performing all other operations using the dedicated netlink
> protocol?
>
> RTNL interface usually implemented for some standalone interface
> types, e.g. VLAN, GRE, etc. Here we need a userspace application
> anyway to be able to use the network device to forward traffic, and
> the module implements the dedicated GENL protocol. So why not just
> introduce OVPN_CMD_NEW_IFACE and OVPN_CMD_DEL_IFACE commands to the
> GENL interface? It looks like this will simplify the userspace part by
> using the single GENL interface for any management operations.

RTNL is netlink. The standard way to create network devices should
be available with newlink message as in:

# ip link add dev myvpn type ovpn <options>