From: Willy Tarreau <w@1wt.eu>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Nebojsa Miljanovic <neb@alcatel-lucent.com>,
linux-kernel@vger.kernel.org, "Kittlitz,
Edward (Ned)" <nkittlitz@alcatel-lucent.com>,
asweeney@alcatel-lucent.com, "Polhemus,
William (Bart)" <bpolhemus@alcatel-lucent.com>
Subject: Re: SO_REUSEADDR not allowing server and client to use same port
Date: Thu, 28 Feb 2008 21:41:47 +0100 [thread overview]
Message-ID: <20080228204146.GE8953@1wt.eu> (raw)
In-Reply-To: <20080228201926.558c4e7c@core>
On Thu, Feb 28, 2008 at 08:19:26PM +0000, Alan Cox wrote:
> > Currently, Linux does not allow reuse of same local port for both TCP server and
> > TCP client. I understand that there may be a need to prevent two servers from
>
> Think about what happens for simultaneous connect (that obscure little
> corner of the tcp/ip spec). Now think about what it means for security.
>
> ALan
exactly. That's why I think that requiring the server to explicitly allow
socket reuse is mandatory. On another side of the problem, I really think
that we should make the simultaneous connect configurable. I've been patching
all of my own 2.4 kernels for a while to add a config option to turn it off
because there is a real security issue with this on. At least for mainline,
it should be a sysctl. No stateful firewall I know supports the feature, so
legitimate uses of this feature are likely very very small.
Willy
next prev parent reply other threads:[~2008-02-28 20:42 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-02-28 18:15 SO_REUSEADDR not allowing server and client to use same port Nebojsa Miljanovic
2008-02-28 18:30 ` Phil Oester
2008-02-28 20:19 ` Alan Cox
2008-02-28 20:41 ` Willy Tarreau [this message]
2008-03-13 19:18 ` Nebojsa Miljanovic
2008-03-15 13:34 ` Alan Cox
2008-03-17 16:43 ` Nebojsa Miljanovic
2008-03-17 17:30 ` Alan Cox
2008-03-17 18:17 ` Nebojsa Miljanovic
2008-03-18 5:48 ` Willy Tarreau
2008-02-28 20:36 ` Willy Tarreau
2008-02-28 20:44 ` Nebojsa Miljanovic
-- strict thread matches above, loose matches on Subject: below --
2008-02-28 19:00 Nebojsa Miljanovic
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