Re: [PATCH net 1/2] sctp: Fix bundling of SHUTDOWN with COOKIE-ACK

[Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>]

On Tue, Apr 21, 2020 at 10:03:41PM +0300, Jere Leppänen wrote:
> When we start shutdown in sctp_sf_do_dupcook_a(), we want to bundle
> the SHUTDOWN with the COOKIE-ACK to ensure that the peer receives them
> at the same time and in the correct order. This bundling was broken by
> commit 4ff40b86262b ("sctp: set chunk transport correctly when it's a
> new asoc"), which assigns a transport for the COOKIE-ACK, but not for
> the SHUTDOWN.
> 
> Fix this by passing a reference to the COOKIE-ACK chunk as an argument
> to sctp_sf_do_9_2_start_shutdown() and onward to
> sctp_make_shutdown(). This way the SHUTDOWN chunk is assigned the same
> transport as the COOKIE-ACK chunk, which allows them to be bundled.
> 
> In sctp_sf_do_9_2_start_shutdown(), the void *arg parameter was
> previously unused. Now that we're taking it into use, it must be a
> valid pointer to a chunk, or NULL. There is only one call site where
> it's not, in sctp_sf_autoclose_timer_expire(). Fix that too.
> 
> Fixes: 4ff40b86262b ("sctp: set chunk transport correctly when it's a new asoc")
> Signed-off-by: Jere Leppänen <jere.leppanen@nokia.com>

Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>