sctp: do trace_sctp_probe after SACK validation and check (356b23c0) · Commits · 戴 / test

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 chunk sanity tests, but keep doing trace if the SACK received is out of order, for the out-of-order SACK is valuable to congestion control debugging. v1->v2: - keep doing SCTP trace if the SACK is out of order as Marcelo's suggestion. v2->v3: - regenerate the patch as v2 generated on top of v1, and add 'net-next' tag to the new one as Marcelo's comments. Signed-off-by:

Kevin Kou <qdkevin.kou@gmail.com> Acked-by:

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

Neil Horman <nhorman@tuxdriver.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

net/sctp/sm_statefuns.c

+9 −9

Original line number	Diff line number	Diff line
		@@ -3281,8 +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);

		@@ -3299,6 +3297,15 @@ enum sctp_disposition sctp_sf_eat_sack_6_2(struct net *net,
		chunk->subh.sack_hdr = sackh;
		ctsn = ntohl(sackh->cum_tsn_ack);

		/* If Cumulative TSN Ack beyond the max tsn currently
		* send, terminating the association and respond to the
		* sender with an ABORT.
		*/
		if (TSN_lte(asoc->next_tsn, ctsn))
		return sctp_sf_violation_ctsn(net, ep, asoc, type, arg, commands);

		trace_sctp_probe(ep, asoc, chunk);

		/* i) If Cumulative TSN Ack is less than the Cumulative TSN
		* Ack Point, then drop the SACK. Since Cumulative TSN
		* Ack is monotonically increasing, a SACK whose
		@@ -3312,13 +3319,6 @@ enum sctp_disposition sctp_sf_eat_sack_6_2(struct net *net,
		return SCTP_DISPOSITION_DISCARD;
		}

		/* If Cumulative TSN Ack beyond the max tsn currently
		* send, terminating the association and respond to the
		* sender with an ABORT.
		*/
		if (!TSN_lt(ctsn, asoc->next_tsn))
		return sctp_sf_violation_ctsn(net, ep, asoc, type, arg, commands);

		/* Return this SACK for further processing. */
		sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK, SCTP_CHUNK(chunk));

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