Re: [PATCH net-next v12 11/22] ovpn: implement TCP transport

[Antonio Quartulli]

On 09/12/2024 11:46, Matthieu Baerts wrote:
> Hi Antonio,
>
> Thank you for working on this, and sharing your work here!
>
> On 05/12/2024 00:09, Antonio Quartulli wrote:
> > On 04/12/2024 23:52, Antonio Quartulli wrote:
> > > Paolo,
> > >
> > > On 04/12/2024 12:15, Antonio Quartulli wrote:
> > > [...]
> > > > > > +        mutex_lock(&tcp6_prot_mutex);
> > > > > > +        if (!ovpn_tcp6_prot.recvmsg)
> > > > > > +            ovpn_tcp_build_protos(&ovpn_tcp6_prot, &ovpn_tcp6_ops,
> > > > > > +                          sock->sk->sk_prot,
> > > > > > +                          sock->sk->sk_socket->ops);
> > > > > > +        mutex_unlock(&tcp6_prot_mutex);
> > > > >
> > > > > This looks like an hack to avoid a build dependency on IPV6, I think
> > > > > the
> > > > > explicit
> > > >
> > > > I happily copied this approach from espintcp.c:espintcp_init_sk() :-D
> > > >
> > > > > #if IS_ENABLED(CONFIG_IPV6)
> > > > >
> > > > > at init time should be preferable
> > >
> > > To get this done at init time I need inet6_stream_ops to be
> > > accessible, but it seems there is no EXPORT_SYMBOL() for this object.
> > >
> > > However, I see that mptcp/protocol.c is happily accessing it.
> > > Any clue how this is possible?
> >
> > I answer myself: mptcp is not tristate and it can only be compiled as
> > built-in.
>
> Indeed, that's why.
>
> Talking about MPTCP, by chance, do you plan to support it later on? :)

Hi Matthieu,

It is not on our current roadmap (TCP doesn't get much love in the VPN 
world), but I agree it could be an interesting option to explore!

I have to admit that I haven't played much with MPTCP myself yet, but I 
am more than happy to talk about potential advantages for the ovpn use case.

Cheers,


--
Antonio Quartulli
OpenVPN Inc.