Re: FreeBSD 7 TCP syncache fix: request for testers

From: Eygene Ryabinkin <rea-fbsd_at_codelabs.ru>
Date: Thu, 12 Jul 2007 08:01:15 +0400
Good day.

Wed, Jul 11, 2007 at 10:04:23AM +0400, Eygene Ryabinkin wrote:
> OK, maybe I have something that can be related to this bug.  It
> provokes another message, 'Spurious RST', but can be correlated
> with your guess.  What is happening is that when one side closes
> the connection and releases the socket (running -CURRENT) while the
> other one is still pushing data through the connection, we are
> getting 'Spurious RST' messages.  This happens, because we are
> checking the 'so->so_state' for the presence of the 'SS_NOFDREF'
> flag (tcp_input.c, version 1.361, line 1581) and dropping such
> connections with RST.  But the connection was already closed (living
> in the FIN-WAIT-2 state, to be precise) from that side, so it
> provokes the debug message.

To clarify one point: the first RST is due to the SS_NOFDREF flag.
The rest of RSTs are spitted out because the corresponding connection
was closed by tcp_close() just before the first RST.
-- 
Eygene
Received on Thu Jul 12 2007 - 02:01:23 UTC

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