From: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
To: Kevin Kou <qdkevin.kou@gmail.com>
Cc: vyasevich@gmail.com, nhorman@tuxdriver.com, davem@davemloft.net,
linux-sctp@vger.kernel.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] sctp: do trace_sctp_probe after SACK validation and check
Date: Fri, 20 Dec 2019 13:17:56 -0300 [thread overview]
Message-ID: <20191220161756.GE5058@localhost.localdomain> (raw)
In-Reply-To: <20191220044703.88-1-qdkevin.kou@gmail.com>
On Fri, Dec 20, 2019 at 04:47:03AM +0000, Kevin Kou wrote:
> The function sctp_sf_eat_sack_6_2 now performs
> the Verification Tag validation, Chunk length validation, Bogu check,
> and also the detection of out-of-order SACK based on the RFC2960
> Section 6.2 at the beginning, and finally performs the further
> processing of SACK. The trace_sctp_probe now triggered before
> the above necessary validation and check.
>
> This patch is to do the trace_sctp_probe after the necessary check
> and validation to SACK.
>
> Signed-off-by: Kevin Kou <qdkevin.kou@gmail.com>
> ---
> net/sctp/sm_statefuns.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c
> index 42558fa..b4a54df 100644
> --- a/net/sctp/sm_statefuns.c
> +++ b/net/sctp/sm_statefuns.c
> @@ -3281,7 +3281,6 @@ enum sctp_disposition sctp_sf_eat_sack_6_2(struct net *net,
> struct sctp_sackhdr *sackh;
> __u32 ctsn;
>
> - trace_sctp_probe(ep, asoc, chunk);
>
> if (!sctp_vtag_verify(chunk, asoc))
> return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
> @@ -3319,6 +3318,8 @@ enum sctp_disposition sctp_sf_eat_sack_6_2(struct net *net,
> if (!TSN_lt(ctsn, asoc->next_tsn))
> return sctp_sf_violation_ctsn(net, ep, asoc, type, arg, commands);
>
> + trace_sctp_probe(ep, asoc, chunk);
> +
Moving it here will be after the check against ctsn_ack_point, which
could cause duplicated SACKs to be missed from the log.
Yes, from the sender-side CC we don't care about it (yet), but it
helps to spot probably avoidable retransmissions.
I think this is cleaning up the noise too much. I can agree with
moving it to after the chunk sanity tests, though.
> /* Return this SACK for further processing. */
> sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK, SCTP_CHUNK(chunk));
>
> --
> 1.8.3.1
>
next prev parent reply other threads:[~2019-12-20 16:18 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-20 4:47 [PATCH] sctp: do trace_sctp_probe after SACK validation and check Kevin Kou
2019-12-20 12:32 ` Neil Horman
2019-12-20 16:17 ` Marcelo Ricardo Leitner [this message]
2019-12-21 5:52 ` kevin kou
2019-12-22 4:22 ` Kevin Kou
2019-12-23 13:26 ` Marcelo Ricardo Leitner
2019-12-24 6:56 ` Kevin Kou
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