Re: [PATCH 3/4] sctp: Fix to handle SHUTDOWN in SHUTDOWN-PENDING state

[David Miller <davem@davemloft.net>]

From: Vlad Yasevich <vladislav.yasevich@hp.com>
Date: Tue, 21 Oct 2008 22:08:46 -0400

> If SHUTDOWN is received in SHUTDOWN-PENDING state, enpoint should enter
> the SHUTDOWN-RECEIVED state and check the Cumulative TSN Ack field of
> the SHUTDOWN chunk (RFC 4960 Section 9.2). If the SHUTDOWN chunk can
> acknowledge all of the send DATA chunks, SHUTDOWN-ACK should be sent.
> 
> But now endpoint just silently discarded the SHUTDOWN chunk.
> 
> SHUTDOWN received in SHUTDOWN-PENDING state can happend when the last
> SACK is lost by network, or the SHUTDOWN chunk can acknowledge all of
> the received DATA chunks. The packet sequence(SACK lost) is like this:
> 
> Endpoint A                       Endpoint B       ULP
> (ESTABLISHED)                    (ESTABLISHED)
> 
>                <-----------      DATA
>                                              <--- shutdown
>                                  Enter SHUTDOWN-PENDING state
>   SACK         ----lost---->
> 
>   SHUTDOWN(*1) ------------>
> 
>                <-----------      SHUTDOWN-ACK
> 
>  (*1) silently discarded now.
> 
> This patch fix to handle SHUTDOWN in SHUTDOWN-PENDING state as the same
> as ESTABLISHED state.
> 
> Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
> Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>

Applied.