netdev - Re: tcp: disallow bind() to reuse addr/port regression in 2.6.38

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Date:	Sat, 2 Apr 2011 23:00:33 +0200
From:	Cyril Bonté <cyril.bonte@...e.fr>
To:	Eric Dumazet <eric.dumazet@...il.com>
Cc:	Willy Tarreau <w@....eu>, netdev@...r.kernel.org,
	Daniel Baluta <daniel.baluta@...il.com>,
	Gaspar Chilingarov <gasparch@...il.com>,
	Charles Duffy <charles@...is.net>
Subject: Re: tcp: disallow bind() to reuse addr/port regression in 2.6.38

Le samedi 2 avril 2011 22:37:27, Willy Tarreau a écrit :
> On Sat, Apr 02, 2011 at 09:44:55PM +0200, Eric Dumazet wrote:
> > Is Cyril program running OK on FreeBsd ?
> 
> I don't think so, as from memories, both FreeBSD and OpenBSD fail
> on isten() after a shutdown(SHUT_RD), hence the strange looking
> shut+listen+shut sequence you noticed (in order to detect whether
> listen will work again or not).

Well, I've just tested it on FreeBSD 8.1.
As Willy said, the listen() fails but what I observe is that as soon as 
shutdown(SHUT_RW) is called, it is possible to bind a new socket on the same 
port. A modified version of the program to sleep after the shutdown shows that 
launching 3 processes in parallel (delayed to let them bind then shutdown) 
will give 3 connections in CLOSE state.

-- 
Cyril Bonté
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