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>
This commit is contained in:
Kevin Kou 2019-12-25 08:27:25 +00:00 committed by David S. Miller
parent 0df9528736
commit 356b23c073

View File

@ -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));