Subject: Re: [PATCH,RFC] explicit connection confirmation

From: Lennert Buytenhek <[email-masked]>
Date: Thu, 7 Nov 2002 07:09:56 -0500

On Thu, Nov 07, 2002 at 12:27:33PM +0100, bert hubert wrote:

> > - Sockets returned from accept() on this socket after this will be
> >   sockets in the SYN_RECV state instead of the ESTABLISHED state
> >   (unless syncookies had to be used).  By writing to the socket,
> >   you cause a SYN-ACK to be sent, and by immediately closing the
> >   socket you cause a RST to be sent.
> 
> And reading, like a webserver would do?

Will do nothing, but this can easily be changed.

I remind you of the fact that this option has to be explicitly
enabled on a listening socket, so that apps have to be adapted to
use the new interface anyway.

> I think this approach smells, btw - doesn't this mean that processes
> will now be woken up on receiving a SYN instead of after completion
> of the handshake?

Yes, it does mean this.  You are free to suggest alternatives.

> Would make a synflood all the more interesting..

In case of a synflood, the TCP stack will fall back to sending
syncookies as it normally does.

cheers,
Lennert