Commit 0fc2ea92 authored by Xin Long's avatar Xin Long Committed by David S. Miller

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: default avatarXin Long <lucien.xin@gmail.com>
Acked-by: default avatarMarcelo R. Leitner <marcelo.leitner@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 8e0c3b73
......@@ -33,6 +33,7 @@
struct sctp_stream_interleave {
__u16 data_chunk_len;
__u16 ftsn_chunk_len;
/* (I-)DATA process */
struct sctp_chunk *(*make_datafrag)(const struct sctp_association *asoc,
const struct sctp_sndrcvinfo *sinfo,
......@@ -49,6 +50,7 @@ struct sctp_stream_interleave {
void (*abort_pd)(struct sctp_ulpq *ulpq, gfp_t gfp);
/* (I-)FORWARD-TSN process */
void (*generate_ftsn)(struct sctp_outq *q, __u32 ctsn);
bool (*validate_ftsn)(struct sctp_chunk *chunk);
};
void sctp_stream_interleave_init(struct sctp_stream *stream);
......
......@@ -1443,6 +1443,16 @@ static inline __u16 sctp_datahdr_len(const struct sctp_stream *stream)
return stream->si->data_chunk_len - sizeof(struct sctp_chunkhdr);
}
static inline __u16 sctp_ftsnchk_len(const struct sctp_stream *stream)
{
return stream->si->ftsn_chunk_len;
}
static inline __u16 sctp_ftsnhdr_len(const struct sctp_stream *stream)
{
return stream->si->ftsn_chunk_len - sizeof(struct sctp_chunkhdr);
}
/* SCTP_GET_ASSOC_STATS counters */
struct sctp_priv_assoc_stats {
/* Maximum observed rto in the association during subsequent
......
......@@ -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)
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)
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));
......
......@@ -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];
}
......
......@@ -1153,8 +1153,49 @@ static void sctp_generate_iftsn(struct sctp_outq *q, __u32 ctsn)
}
}
#define _sctp_walk_ifwdtsn(pos, chunk, end) \
for (pos = chunk->subh.ifwdtsn_hdr->skip; \
(void *)pos < (void *)chunk->subh.ifwdtsn_hdr->skip + (end); pos++)
#define sctp_walk_ifwdtsn(pos, ch) \
_sctp_walk_ifwdtsn((pos), (ch), ntohs((ch)->chunk_hdr->length) - \
sizeof(struct sctp_ifwdtsn_chunk))
static bool sctp_validate_fwdtsn(struct sctp_chunk *chunk)
{
struct sctp_fwdtsn_skip *skip;
__u16 incnt;
if (chunk->chunk_hdr->type != SCTP_CID_FWD_TSN)
return false;
incnt = chunk->asoc->stream.incnt;
sctp_walk_fwdtsn(skip, chunk)
if (ntohs(skip->stream) >= incnt)
return false;
return true;
}
static bool sctp_validate_iftsn(struct sctp_chunk *chunk)
{
struct sctp_ifwdtsn_skip *skip;
__u16 incnt;
if (chunk->chunk_hdr->type != SCTP_CID_I_FWD_TSN)
return false;
incnt = chunk->asoc->stream.incnt;
sctp_walk_ifwdtsn(skip, chunk)
if (ntohs(skip->stream) >= incnt)
return false;
return true;
}
static struct sctp_stream_interleave sctp_stream_interleave_0 = {
.data_chunk_len = sizeof(struct sctp_data_chunk),
.ftsn_chunk_len = sizeof(struct sctp_fwdtsn_chunk),
/* DATA process functions */
.make_datafrag = sctp_make_datafrag_empty,
.assign_number = sctp_chunk_assign_ssn,
......@@ -1166,10 +1207,12 @@ static struct sctp_stream_interleave sctp_stream_interleave_0 = {
.abort_pd = sctp_ulpq_abort_pd,
/* FORWARD-TSN process functions */
.generate_ftsn = sctp_generate_fwdtsn,
.validate_ftsn = sctp_validate_fwdtsn,
};
static struct sctp_stream_interleave sctp_stream_interleave_1 = {
.data_chunk_len = sizeof(struct sctp_idata_chunk),
.ftsn_chunk_len = sizeof(struct sctp_ifwdtsn_chunk),
/* I-DATA process functions */
.make_datafrag = sctp_make_idatafrag_empty,
.assign_number = sctp_chunk_assign_mid,
......@@ -1181,6 +1224,7 @@ static struct sctp_stream_interleave sctp_stream_interleave_1 = {
.abort_pd = sctp_intl_abort_pd,
/* I-FORWARD-TSN process functions */
.generate_ftsn = sctp_generate_iftsn,
.validate_ftsn = sctp_validate_iftsn,
};
void sctp_stream_interleave_init(struct sctp_stream *stream)
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment