sctp: implement validate_ftsn for sctp_stream_interleave

validate_ftsn is added as a member of sctp_stream_interleave, used to
validate ssn/chunk type for fwdtsn or mid (message id)/chunk type for
ifwdtsn, called in sctp_sf_eat_fwd_tsn, just as validate_data.

If this check fails, an abort packet will be sent, as said in section
2.3.1 of RFC8260.

As ifwdtsn and fwdtsn chunks have different length, it also defines
ftsn_chunk_len for sctp_stream_interleave to describe the chunk size.
Then it replaces all sizeof(struct sctp_fwdtsn_chunk) with
sctp_ftsnchk_len.

It also adds the process for ifwdtsn in rx path. As Marcelo pointed
out, there's no need to add event table for ifwdtsn, but just share
prsctp_chunk_event_table with fwdtsn's. It would drop fwdtsn chunk
for ifwdtsn and drop ifwdtsn chunk for fwdtsn by calling validate_ftsn
in sctp_sf_eat_fwd_tsn.

After this patch, the ifwdtsn can be accepted.

Note that this patch also removes the sctp.intl_enable check for
idata chunks in sctp_chunk_event_lookup, as it will do this check
in validate_data later.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo R. Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Xin Long
2017-12-15 00:41:27 +08:00
committed by David S. Miller
parent 8e0c3b73ce
commit 0fc2ea922c
5 changed files with 66 additions and 18 deletions

View File

@@ -985,14 +985,14 @@ static const struct sctp_sm_table_entry *sctp_chunk_event_lookup(
if (state > SCTP_STATE_MAX)
return &bug;
if (net->sctp.intl_enable && cid == SCTP_CID_I_DATA)
if (cid == SCTP_CID_I_DATA)
cid = SCTP_CID_DATA;
if (cid <= SCTP_CID_BASE_MAX)
return &chunk_event_table[cid][state];
if (net->sctp.prsctp_enable) {
if (cid == SCTP_CID_FWD_TSN)
if (cid == SCTP_CID_FWD_TSN || cid == SCTP_CID_I_FWD_TSN)
return &prsctp_chunk_event_table[0][state];
}