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>

4 files changed, 57 insertions, 6 deletions

diff --git a/net/sctp/output.c b/net/sctp/output.c
index 4a865cd..01a26ee0 100644
--- a/net/sctp/output.c
+++ b/net/sctp/output.c
@@ -313,6 +313,7 @@ static enum sctp_xmit __sctp_packet_append_chunk(struct sctp_packet *packet,
 	/* We believe that this chunk is OK to add to the packet */
 	switch (chunk->chunk_hdr->type) {
 	case SCTP_CID_DATA:
+	case SCTP_CID_I_DATA:
 		/* Account for the data being in the packet */
 		sctp_packet_append_data(packet, chunk);
 		/* Disallow SACK bundling after DATA. */
@@ -724,7 +725,7 @@ static enum sctp_xmit sctp_packet_can_append_data(struct sctp_packet *packet,
 	 * or delay in hopes of bundling a full sized packet.
 	 */
 	if (chunk->skb->len + q->out_qlen > transport->pathmtu -
-		packet->overhead - sizeof(struct sctp_data_chunk) - 4)
+	    packet->overhead - sctp_datachk_len(&chunk->asoc->stream) - 4)
 		/* Enough data queued to fill a packet */
 		return SCTP_XMIT_OK;
 
@@ -759,7 +760,7 @@ static void sctp_packet_append_data(struct sctp_packet *packet,
 
 	asoc->peer.rwnd = rwnd;
 	sctp_chunk_assign_tsn(chunk);
-	sctp_chunk_assign_ssn(chunk);
+	asoc->stream.si->assign_number(chunk);
 }
 
 static enum sctp_xmit sctp_packet_will_fit(struct sctp_packet *packet,
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 306c737..3654e1e 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -2002,7 +2002,20 @@ static int sctp_sendmsg(struct sock *sk, struct msghdr *msg, size_t msg_len)
 		if (err < 0)
 			goto out_free;
 
-		wait_connect = true;
+		/* If stream interleave is enabled, wait_connect has to be
+		 * done earlier than data enqueue, as it needs to make data
+		 * or idata according to asoc->intl_enable which is set
+		 * after connection is done.
+		 */
+		if (sctp_sk(asoc->base.sk)->strm_interleave) {
+			timeo = sock_sndtimeo(sk, 0);
+			err = sctp_wait_for_connect(asoc, &timeo);
+			if (err)
+				goto out_unlock;
+		} else {
+			wait_connect = true;
+		}
+
 		pr_debug("%s: we associated primitively\n", __func__);
 	}
 
@@ -3180,7 +3193,7 @@ static int sctp_setsockopt_maxseg(struct sock *sk, char __user *optval, unsigned
 		if (val == 0) {
 			val = asoc->pathmtu - sp->pf->af->net_header_len;
 			val -= sizeof(struct sctphdr) +
-			       sizeof(struct sctp_data_chunk);
+			       sctp_datachk_len(&asoc->stream);
 		}
 		asoc->user_frag = val;
 		asoc->frag_point = sctp_frag_point(asoc, asoc->pathmtu);
diff --git a/net/sctp/stream_interleave.c b/net/sctp/stream_interleave.c
index 397c3c1..3ac47e7 100644
--- a/net/sctp/stream_interleave.c
+++ b/net/sctp/stream_interleave.c
@@ -57,16 +57,53 @@ static struct sctp_chunk *sctp_make_idatafrag_empty(
 	return retval;
 }
 
+static void sctp_chunk_assign_mid(struct sctp_chunk *chunk)
+{
+	struct sctp_stream *stream;
+	struct sctp_chunk *lchunk;
+	__u32 cfsn = 0;
+	__u16 sid;
+
+	if (chunk->has_mid)
+		return;
+
+	sid = sctp_chunk_stream_no(chunk);
+	stream = &chunk->asoc->stream;
+
+	list_for_each_entry(lchunk, &chunk->msg->chunks, frag_list) {
+		struct sctp_idatahdr *hdr;
+
+		lchunk->has_mid = 1;
+
+		if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED)
+			continue;
+
+		hdr = lchunk->subh.idata_hdr;
+
+		if (lchunk->chunk_hdr->flags & SCTP_DATA_FIRST_FRAG)
+			hdr->ppid = lchunk->sinfo.sinfo_ppid;
+		else
+			hdr->fsn = htonl(cfsn++);
+
+		if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG)
+			hdr->mid = htonl(sctp_mid_next(stream, out, sid));
+		else
+			hdr->mid = htonl(sctp_mid_peek(stream, out, sid));
+	}
+}
+
 static struct sctp_stream_interleave sctp_stream_interleave_0 = {
 	.data_chunk_len		= sizeof(struct sctp_data_chunk),
 	/* DATA process functions */
 	.make_datafrag		= sctp_make_datafrag_empty,
+	.assign_number		= sctp_chunk_assign_ssn,
 };
 
 static struct sctp_stream_interleave sctp_stream_interleave_1 = {
 	.data_chunk_len		= sizeof(struct sctp_idata_chunk),
 	/* I-DATA process functions */
 	.make_datafrag		= sctp_make_idatafrag_empty,
+	.assign_number		= sctp_chunk_assign_mid,
 };
 
 void sctp_stream_interleave_init(struct sctp_stream *stream)
diff --git a/net/sctp/ulpevent.c b/net/sctp/ulpevent.c
index 5447228..650b634 100644
--- a/net/sctp/ulpevent.c
+++ b/net/sctp/ulpevent.c
@@ -443,8 +443,8 @@ struct sctp_ulpevent *sctp_ulpevent_make_send_failed(
 		goto fail;
 
 	/* Pull off the common chunk header and DATA header.  */
-	skb_pull(skb, sizeof(struct sctp_data_chunk));
-	len -= sizeof(struct sctp_data_chunk);
+	skb_pull(skb, sctp_datachk_len(&asoc->stream));
+	len -= sctp_datachk_len(&asoc->stream);
 
 	/* Embed the event fields inside the cloned skb.  */
 	event = sctp_skb2event(skb);