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Date:   Fri, 12 Aug 2022 11:44:27 -0700
From:   Stephen Hemminger <stephen@networkplumber.org>
To:     Sergey Ryazanov <ryazanov.s.a@gmail.com>
Cc:     Antonio Quartulli <antonio@openvpn.net>, netdev@vger.kernel.org,
        David Miller <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>,
        open list <linux-kernel@vger.kernel.org>
Subject: Re: [RFC v2] net: introduce OpenVPN Data Channel Offload (ovpn-dco)
Message-ID: <20220812114427.05f7393a@hermes.local>
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References: <20220719014704.21346-2-antonio@openvpn.net>
        <20220803153152.11189-1-antonio@openvpn.net>
        <CAHNKnsQnHAdxC-XhC9RP-cFp0d-E4YGb+7ie3WymXVL9N-QS6A@mail.gmail.com>
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On Fri, 12 Aug 2022 21:34:33 +0300
Sergey Ryazanov <ryazanov.s.a@gmail.com> 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>