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Date: Tue, 12 Dec 2017 17:25:54 +0800
From: Xin Long <lucien.xin@...il.com>
To: network dev <netdev@...r.kernel.org>, linux-sctp@...r.kernel.org
Cc: Marcelo Ricardo Leitner <marcelo.leitner@...il.com>,
Neil Horman <nhorman@...driver.com>, davem@...emloft.net
Subject: [PATCH net-next 3/8] 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.
Signed-off-by: Xin Long <lucien.xin@...il.com>
---
include/net/sctp/stream_interleave.h | 2 ++
include/net/sctp/structs.h | 10 ++++++++
net/sctp/sm_statefuns.c | 24 +++++++-------------
net/sctp/sm_statetable.c | 3 ++-
net/sctp/stream_interleave.c | 44 ++++++++++++++++++++++++++++++++++++
5 files changed, 66 insertions(+), 17 deletions(-)
diff --git a/include/net/sctp/stream_interleave.h b/include/net/sctp/stream_interleave.h
index 66267db..0db15b5 100644
--- a/include/net/sctp/stream_interleave.h
+++ b/include/net/sctp/stream_interleave.h
@@ -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);
diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index b7720d6..8ac4d5c 100644
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -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
diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c
index c609c54..541f347 100644
--- a/net/sctp/sm_statefuns.c
+++ b/net/sctp/sm_statefuns.c
@@ -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));
diff --git a/net/sctp/sm_statetable.c b/net/sctp/sm_statetable.c
index 8c9bb41..03a5d7e 100644
--- a/net/sctp/sm_statetable.c
+++ b/net/sctp/sm_statetable.c
@@ -992,7 +992,8 @@ static const struct sctp_sm_table_entry *sctp_chunk_event_lookup(
return &chunk_event_table[cid][state];
if (net->sctp.prsctp_enable) {
- if (cid == SCTP_CID_FWD_TSN)
+ if (cid == SCTP_CID_FWD_TSN ||
+ (net->sctp.intl_enable && cid == SCTP_CID_I_FWD_TSN))
return &prsctp_chunk_event_table[0][state];
}
diff --git a/net/sctp/stream_interleave.c b/net/sctp/stream_interleave.c
index 2ead372..cc4a5e3 100644
--- a/net/sctp/stream_interleave.c
+++ b/net/sctp/stream_interleave.c
@@ -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)
--
2.1.0
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