Re: netfilter expected behavior for established connections

On Wed, 12 Mar 2025 at 19:20, Florian Westphal <[email protected]> wrote:
>
> Antonio Ojea <[email protected]> wrote:
> > heh, I got bitten for that too, that is why I have
> >
> > echo PING >&3 && read line <&3
> >
> > the moment that you read it from the fd, it does not come back to the
> > socket and you break the loop.
>
> AFAIU the read could happen before socat managed to read from
> the pipe (so nothing is sent over network).
>
> Or there could have been several writes over the network,
> not just 'exactly one write'.

I tcpdumped to verify the behavior, but let me work on it and use a
different approach that is not so racy and random, I just wanted to
validate my assumption on the expected behavior