[PATCH] sctp: do trace_sctp_probe after SACK validation and check

From: Kevin Kou
Date: Thu Dec 19 2019 - 23:47:25 EST


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@xxxxxxxxx>
---
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);
+
/* Return this SACK for further processing. */
sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK, SCTP_CHUNK(chunk));

--
1.8.3.1