Re: [PATCH net 3/5] sctp: only allow the asoc reset when the asoc outq is empty

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

On Sat, Nov 25, 2017 at 09:05:34PM +0800, Xin Long wrote:
> As it says in rfc6525#section5.1.4, before sending the request,
> 
>    C2:  The sender has either no outstanding TSNs or considers all
>         outstanding TSNs abandoned.
> 
> Prior to this patch, it tried to consider all outstanding TSNs abandoned
> by dropping all chunks in all outqs with sctp_outq_free (even including
> sacked, retransmit and transmitted queues) when doing this reset, which
> is too aggressive.
> 
> To make it work gently, this patch will only allow the asoc reset when
> the sender has no outstanding TSNs by checking if unsent, transmitted
> and retransmit are all empty with sctp_outq_is_empty before sending
> and processing the request.
> 
> Fixes: 692787cef651 ("sctp: implement receiver-side procedures for the SSN/TSN Reset Request Parameter")
> Signed-off-by: Xin Long <lucien.xin@gmail.com>

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

> ---
>  net/sctp/stream.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/net/sctp/stream.c b/net/sctp/stream.c
> index b209037..f3b7d27 100644
> --- a/net/sctp/stream.c
> +++ b/net/sctp/stream.c
> @@ -406,6 +406,9 @@ int sctp_send_reset_assoc(struct sctp_association *asoc)
>  	if (asoc->strreset_outstanding)
>  		return -EINPROGRESS;
>  
> +	if (!sctp_outq_is_empty(&asoc->outqueue))
> +		return -EAGAIN;
> +
>  	chunk = sctp_make_strreset_tsnreq(asoc);
>  	if (!chunk)
>  		return -ENOMEM;
> @@ -728,6 +731,12 @@ struct sctp_chunk *sctp_process_strreset_tsnreq(
>  		}
>  		goto err;
>  	}
> +
> +	if (!sctp_outq_is_empty(&asoc->outqueue)) {
> +		result = SCTP_STRRESET_IN_PROGRESS;
> +		goto err;
> +	}
> +
>  	asoc->strreset_inseq++;
>  
>  	if (!(asoc->strreset_enable & SCTP_ENABLE_RESET_ASSOC_REQ))
> -- 
> 2.1.0
> 
> --
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