From mboxrd@z Thu Jan  1 00:00:00 1970
From: Hannes Frederic Sowa <hannes@stressinduktion.org>
Subject: Re: Add a SOCK_DESTROY operation to close sockets from userspace
Date: Wed, 18 Nov 2015 15:56:30 +0100
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Cc: Eric Dumazet <eric.dumazet@gmail.com>,
	Stephen Hemminger <stephen@networkplumber.org>,
	netdev@vger.kernel.org, Eric Dumazet <edumazet@google.com>,
	Erik Kline <ek@google.com>,
	=?UTF-8?Q?Maciej=20=C5=BBenczykowski?= <maze@google.com>,
	Dmitry Torokhov <dtor@google.com>
To: Lorenzo Colitti <lorenzo@google.com>
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On Wed, Nov 18, 2015, at 15:45, Lorenzo Colitti wrote:
> On Wed, Nov 18, 2015 at 10:31 PM, Hannes Frederic Sowa
> <hannes@stressinduktion.org> wrote:
> > I was not saying using tcp_close literally, sorry for not making that
> > clear, but just model the state transitions after tcp_close. At least it
> > seems like a normal close to me.
> 
> But it shouldn't be a normal close. Consider calling SOCK_DESTROY on a
> socket that is streaming data to a peer. If SOCK_DESTROY results in
> the kernel sending a FIN, the remote side might think that the sender
> closed the connection gracefully, even though the local side aborted
> the connection.

Oh, yes, I understand. The connection wasn't closed by the application
but by the administrator forcefully. So we should never indicate a
successful TCP shutdown with FIN but with RST. A TIME_WAIT period
actuallty still seems useful to me, maybe with different semantics, only
RST incoming data?

Bye,
Hannes