From 356b23c073dd063427102329b296061855b912d9 Mon Sep 17 00:00:00 2001 From: Kevin Kou Date: Wed, 25 Dec 2019 08:27:25 +0000 Subject: sctp: do trace_sctp_probe after SACK validation and check 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 Acked-by: Marcelo Ricardo Leitner Acked-by: Neil Horman Signed-off-by: David S. Miller --- net/sctp/sm_statefuns.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) (limited to 'net/sctp/sm_statefuns.c') diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c index 42558fa3f3e4..748e3b19ec1d 100644 --- a/net/sctp/sm_statefuns.c +++ b/net/sctp/sm_statefuns.c @@ -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)); -- cgit v1.2.3-59-g8ed1b