sctp: implement assign_number for sctp_stream_interleave

assign_number is added as a member of sctp_stream_interleave, used
to assign ssn for data or mid (message id) for idata, called in
sctp_packet_append_data. sctp_chunk_assign_ssn is left as it is,
and sctp_chunk_assign_mid is added for sctp_stream_interleave_1.

This procedure is described in section 2.2.2 of RFC8260.

All sizeof(struct sctp_data_chunk) in tx path is replaced with
sctp_datachk_len, to make it right for idata as well. And also
adjust sctp_chunk_is_data for SCTP_CID_I_DATA.

After this patch, idata can be built and sent in tx path.

Note that if sp strm_interleave is set, it has to wait_connect in
sctp_sendmsg, as asoc intl_enable need to be known after 4 shake-
hands, to decide if it should use data or idata later. data and
idata can't be mixed to send in one asoc.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

5 files changed, 26 insertions, 8 deletions

diff --git a/include/net/sctp/constants.h b/include/net/sctp/constants.h
index deaafa9..20ff237 100644
--- a/include/net/sctp/constants.h
+++ b/include/net/sctp/constants.h
@@ -145,12 +145,13 @@ SCTP_SUBTYPE_CONSTRUCTOR(OTHER,		enum sctp_event_other,	other)
 SCTP_SUBTYPE_CONSTRUCTOR(PRIMITIVE,	enum sctp_event_primitive, primitive)
 
 
-#define sctp_chunk_is_data(a) (a->chunk_hdr->type == SCTP_CID_DATA)
+#define sctp_chunk_is_data(a) (a->chunk_hdr->type == SCTP_CID_DATA || \
+			       a->chunk_hdr->type == SCTP_CID_I_DATA)
 
 /* Calculate the actual data size in a data chunk */
-#define SCTP_DATA_SNDSIZE(c) ((int)((unsigned long)(c->chunk_end)\
-		       		- (unsigned long)(c->chunk_hdr)\
-				- sizeof(struct sctp_data_chunk)))
+#define SCTP_DATA_SNDSIZE(c) ((int)((unsigned long)(c->chunk_end) - \
+				    (unsigned long)(c->chunk_hdr) - \
+				    sctp_datachk_len(&c->asoc->stream)))
 
 /* Internal error codes */
 enum sctp_ierror {
diff --git a/include/net/sctp/sctp.h b/include/net/sctp/sctp.h
index 6f79415..20c0c1b 100644
--- a/include/net/sctp/sctp.h
+++ b/include/net/sctp/sctp.h
@@ -444,13 +444,13 @@ static inline int sctp_frag_point(const struct sctp_association *asoc, int pmtu)
 	int frag = pmtu;
 
 	frag -= sp->pf->af->net_header_len;
-	frag -= sizeof(struct sctphdr) + sizeof(struct sctp_data_chunk);
+	frag -= sizeof(struct sctphdr) + sctp_datachk_len(&asoc->stream);
 
 	if (asoc->user_frag)
 		frag = min_t(int, frag, asoc->user_frag);
 
 	frag = SCTP_TRUNC4(min_t(int, frag, SCTP_MAX_CHUNK_LEN -
-					    sizeof(struct sctp_data_chunk)));
+					    sctp_datachk_len(&asoc->stream)));
 
 	return frag;
 }
diff --git a/include/net/sctp/sm.h b/include/net/sctp/sm.h
index f950186..ca1db89 100644
--- a/include/net/sctp/sm.h
+++ b/include/net/sctp/sm.h
@@ -343,7 +343,7 @@ static inline __u16 sctp_data_size(struct sctp_chunk *chunk)
 	__u16 size;
 
 	size = ntohs(chunk->chunk_hdr->length);
-	size -= sizeof(struct sctp_data_chunk);
+	size -= sctp_datahdr_len(&chunk->asoc->stream);
 
 	return size;
 }
diff --git a/include/net/sctp/stream_interleave.h b/include/net/sctp/stream_interleave.h
index 7b9fa8d..99f399e 100644
--- a/include/net/sctp/stream_interleave.h
+++ b/include/net/sctp/stream_interleave.h
@@ -37,6 +37,7 @@ struct sctp_stream_interleave {
 	struct sctp_chunk *(*make_datafrag)(const struct sctp_association *asoc,
 					    const struct sctp_sndrcvinfo *sinfo,
 					    int len, __u8 flags, gfp_t gfp);
+	void	(*assign_number)(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 96cc898..fd93973 100644
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -399,6 +399,18 @@ void sctp_stream_update(struct sctp_stream *stream, struct sctp_stream *new);
 #define sctp_ssn_skip(stream, type, sid, ssn) \
 	((stream)->type[sid].ssn = ssn + 1)
 
+/* What is the current MID number for this stream? */
+#define sctp_mid_peek(stream, type, sid) \
+	((stream)->type[sid].mid)
+
+/* Return the next MID number for this stream.  */
+#define sctp_mid_next(stream, type, sid) \
+	((stream)->type[sid].mid++)
+
+/* Skip over this mid and all below. */
+#define sctp_mid_skip(stream, type, sid, mid) \
+	((stream)->type[sid].mid = mid + 1)
+
 /*
  * Pointers to address related SCTP functions.
  * (i.e. things that depend on the address family.)
@@ -623,6 +635,7 @@ struct sctp_chunk {
 	__u16	rtt_in_progress:1,	/* This chunk used for RTT calc? */
 		has_tsn:1,		/* Does this chunk have a TSN yet? */
 		has_ssn:1,		/* Does this chunk have a SSN yet? */
+#define has_mid has_ssn
 		singleton:1,		/* Only chunk in the packet? */
 		end_of_packet:1,	/* Last chunk in the packet? */
 		ecn_ce_done:1,		/* Have we processed the ECN CE bit? */
@@ -1360,7 +1373,10 @@ struct sctp_stream_out_ext {
 };
 
 struct sctp_stream_out {
-	__u16	ssn;
+	union {
+		__u32 mid;
+		__u16 ssn;
+	};
 	__u8	state;
 	struct sctp_stream_out_ext *ext;
 };