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sctp: implement validate_ftsn for sctp_stream_interleave

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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
Download Patch File Download Diff File Expand all files Collapse all files

24
net/sctp/sm_statefuns.c
View File

@@ -3957,7 +3957,6 @@ enum sctp_disposition sctp_sf_eat_fwd_tsn(struct net *net,
{
struct sctp_fwdtsn_hdr *fwdtsn_hdr;
struct sctp_chunk *chunk = arg;
struct sctp_fwdtsn_skip *skip;
__u16 len;
__u32 tsn;
@@ -3971,7 +3970,7 @@ enum sctp_disposition sctp_sf_eat_fwd_tsn(struct net *net,
return sctp_sf_unk_chunk(net, ep, asoc, type, arg, commands);
/* Make sure that the FORWARD_TSN chunk has valid length. */
if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk)))
if (!sctp_chunk_length_valid(chunk, sctp_ftsnchk_len(&asoc->stream)))
return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
commands);
@@ -3990,14 +3989,11 @@ enum sctp_disposition sctp_sf_eat_fwd_tsn(struct net *net,
if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
goto discard_noforce;
/* Silently discard the chunk if stream-id is not valid */
sctp_walk_fwdtsn(skip, chunk) {
if (ntohs(skip->stream) >= asoc->stream.incnt)
goto discard_noforce;
}
if (!asoc->stream.si->validate_ftsn(chunk))
goto discard_noforce;
sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
if (len > sizeof(struct sctp_fwdtsn_hdr))
if (len > sctp_ftsnhdr_len(&asoc->stream))
sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
SCTP_CHUNK(chunk));
@@ -4028,7 +4024,6 @@ enum sctp_disposition sctp_sf_eat_fwd_tsn_fast(
{
struct sctp_fwdtsn_hdr *fwdtsn_hdr;
struct sctp_chunk *chunk = arg;
struct sctp_fwdtsn_skip *skip;
__u16 len;
__u32 tsn;
@@ -4042,7 +4037,7 @@ enum sctp_disposition sctp_sf_eat_fwd_tsn_fast(
return sctp_sf_unk_chunk(net, ep, asoc, type, arg, commands);
/* Make sure that the FORWARD_TSN chunk has a valid length. */
if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk)))
if (!sctp_chunk_length_valid(chunk, sctp_ftsnchk_len(&asoc->stream)))
return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
commands);
@@ -4061,14 +4056,11 @@ enum sctp_disposition sctp_sf_eat_fwd_tsn_fast(
if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
goto gen_shutdown;
/* Silently discard the chunk if stream-id is not valid */
sctp_walk_fwdtsn(skip, chunk) {
if (ntohs(skip->stream) >= asoc->stream.incnt)
goto gen_shutdown;
}
if (!asoc->stream.si->validate_ftsn(chunk))
goto gen_shutdown;
sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
if (len > sizeof(struct sctp_fwdtsn_hdr))
if (len > sctp_ftsnhdr_len(&asoc->stream))
sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
SCTP_CHUNK(chunk));