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 <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>
diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c
index 42558fa..748e3b1 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));