Re: [regression] TCP_MD5SIG on established sockets

[Eric Dumazet]

On Tue, Jun 30, 2020 at 1:44 PM David Miller <davem@xxxxxxxxxxxxx> wrote:
>
> From: Eric Dumazet <edumazet@xxxxxxxxxx>
> Date: Tue, 30 Jun 2020 13:39:27 -0700
>
> > The (C) & (B) case are certainly doable.
> >
> > A) case is more complex, I have no idea of breakages of various TCP
> > stacks if a flow got SACK
> > at some point (in 3WHS) but suddenly becomes Reno.
>
> I agree that C and B are the easiest to implement without having to
> add complicated code to handle various negotiated TCP option
> scenerios.
>
> It does seem to be that some entities do A, or did I misread your
> behavioral analysis of various implementations Mathieu?
>
> Thanks.

Yes, another question about Mathieu cases is do determine the behavior
of all these stacks vs :
SACK option
TCP TS option.