Re: [PATCH net] net: ovpn: refuse TCP socket layering with an active ULP

From: Sabrina Dubroca

Date: Wed May 20 2026 - 05:17:28 EST


2026-05-20, 09:22:01 +0200, Antonio Quartulli wrote:
> Hi Sabrina,
>
> On 19/05/2026 16:32, Sabrina Dubroca wrote:
> > mptcp calls tcp_set_ulp() from the setup, maybe ovpn can also do
> > that. detach() may be an issue.
>
> What is your exact concern with detach()? if we prevent other protocols from
> stacking, what is there to deal with in detach()?

IIRC, ULP doesn't have a concept of "detach" (without close). So if
you want to detach and then reattach the same socket, I think the ULP
infra will need some work.

--
Sabrina