On Fri, Dec 20, 2019 at 04:47:03AM +0000, Kevin Kou wrote: > 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); > + Moving it here will be after the check against ctsn_ack_point, which could cause duplicated SACKs to be missed from the log. Yes, from the sender-side CC we don't care about it (yet), but it helps to spot probably avoidable retransmissions. I think this is cleaning up the noise too much. I can agree with moving it to after the chunk sanity tests, though. > /* Return this SACK for further processing. */ > sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK, SCTP_CHUNK(chunk)); > > -- > 1.8.3.1 >
