Merge branch 'sctp-stream-reconfig-fixes'

Xin Long says:

====================
sctp: a bunch of fixes for stream reconfig

This patchset is to make stream reset and asoc reset work more correctly
for stream reconfig.

Thank to Marcelo making them very clear.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sctp/stream.c

@@ -254,6 +254,30 @@ static int sctp_send_reconf(struct sctp_association *asoc,
 	return retval;
 }
 
+static bool sctp_stream_outq_is_empty(struct sctp_stream *stream,
+				      __u16 str_nums, __be16 *str_list)
+{
+	struct sctp_association *asoc;
+	__u16 i;
+
+	asoc = container_of(stream, struct sctp_association, stream);
+	if (!asoc->outqueue.out_qlen)
+		return true;
+
+	if (!str_nums)
+		return false;
+
+	for (i = 0; i < str_nums; i++) {
+		__u16 sid = ntohs(str_list[i]);
+
+		if (stream->out[sid].ext &&
+		    !list_empty(&stream->out[sid].ext->outq))
+			return false;
+	}
+
+	return true;
+}
+
 int sctp_send_reset_streams(struct sctp_association *asoc,
 			    struct sctp_reset_streams *params)
 {
@@ -317,6 +341,11 @@ int sctp_send_reset_streams(struct sctp_association *asoc,
 	for (i = 0; i < str_nums; i++)
 		nstr_list[i] = htons(str_list[i]);
 
+	if (out && !sctp_stream_outq_is_empty(stream, str_nums, nstr_list)) {
+		retval = -EAGAIN;
+		goto out;
+	}
+
 	chunk = sctp_make_strreset_req(asoc, str_nums, nstr_list, out, in);
 
 	kfree(nstr_list);
@@ -377,6 +406,9 @@ int sctp_send_reset_assoc(struct sctp_association *asoc)
 	if (asoc->strreset_outstanding)
 		return -EINPROGRESS;
 
+	if (!sctp_outq_is_empty(&asoc->outqueue))
+		return -EAGAIN;
+
 	chunk = sctp_make_strreset_tsnreq(asoc);
 	if (!chunk)
 		return -ENOMEM;
@@ -563,7 +595,7 @@ struct sctp_chunk *sctp_process_strreset_outreq(
 		flags = SCTP_STREAM_RESET_INCOMING_SSN;
 	}
 
-	nums = (ntohs(param.p->length) - sizeof(*outreq)) / 2;
+	nums = (ntohs(param.p->length) - sizeof(*outreq)) / sizeof(__u16);
 	if (nums) {
 		str_p = outreq->list_of_streams;
 		for (i = 0; i < nums; i++) {
@@ -627,7 +659,7 @@ struct sctp_chunk *sctp_process_strreset_inreq(
 		goto out;
 	}
 
-	nums = (ntohs(param.p->length) - sizeof(*inreq)) / 2;
+	nums = (ntohs(param.p->length) - sizeof(*inreq)) / sizeof(__u16);
 	str_p = inreq->list_of_streams;
 	for (i = 0; i < nums; i++) {
 		if (ntohs(str_p[i]) >= stream->outcnt) {
@@ -636,6 +668,12 @@ struct sctp_chunk *sctp_process_strreset_inreq(
 		}
 	}
 
+	if (!sctp_stream_outq_is_empty(stream, nums, str_p)) {
+		result = SCTP_STRRESET_IN_PROGRESS;
+		asoc->strreset_inseq--;
+		goto err;
+	}
+
 	chunk = sctp_make_strreset_req(asoc, nums, str_p, 1, 0);
 	if (!chunk)
 		goto out;
@@ -687,12 +725,18 @@ struct sctp_chunk *sctp_process_strreset_tsnreq(
 		i = asoc->strreset_inseq - request_seq - 1;
 		result = asoc->strreset_result[i];
 		if (result == SCTP_STRRESET_PERFORMED) {
-			next_tsn = asoc->next_tsn;
+			next_tsn = asoc->ctsn_ack_point + 1;
 			init_tsn =
 				sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map) + 1;
 		}
 		goto err;
 	}
+
+	if (!sctp_outq_is_empty(&asoc->outqueue)) {
+		result = SCTP_STRRESET_IN_PROGRESS;
+		goto err;
+	}
+
 	asoc->strreset_inseq++;
 
 	if (!(asoc->strreset_enable & SCTP_ENABLE_RESET_ASSOC_REQ))
@@ -703,9 +747,10 @@ struct sctp_chunk *sctp_process_strreset_tsnreq(
 		goto out;
 	}
 
-	/* G3: The same processing as though a SACK chunk with no gap report
-	 *     and a cumulative TSN ACK of the Sender's Next TSN minus 1 were
-	 *     received MUST be performed.
+	/* G4: The same processing as though a FWD-TSN chunk (as defined in
+	 *     [RFC3758]) with all streams affected and a new cumulative TSN
+	 *     ACK of the Receiver's Next TSN minus 1 were received MUST be
+	 *     performed.
 	 */
 	max_tsn_seen = sctp_tsnmap_get_max_tsn_seen(&asoc->peer.tsn_map);
 	sctp_ulpq_reasm_flushtsn(&asoc->ulpq, max_tsn_seen);
@@ -720,10 +765,9 @@ struct sctp_chunk *sctp_process_strreset_tsnreq(
 	sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL,
 			 init_tsn, GFP_ATOMIC);
 
-	/* G4: The same processing as though a FWD-TSN chunk (as defined in
-	 *     [RFC3758]) with all streams affected and a new cumulative TSN
-	 *     ACK of the Receiver's Next TSN minus 1 were received MUST be
-	 *     performed.
+	/* G3: The same processing as though a SACK chunk with no gap report
+	 *     and a cumulative TSN ACK of the Sender's Next TSN minus 1 were
+	 *     received MUST be performed.
 	 */
 	sctp_outq_free(&asoc->outqueue);
 
@@ -927,7 +971,8 @@ struct sctp_chunk *sctp_process_strreset_resp(
 
 		outreq = (struct sctp_strreset_outreq *)req;
 		str_p = outreq->list_of_streams;
-		nums = (ntohs(outreq->param_hdr.length) - sizeof(*outreq)) / 2;
+		nums = (ntohs(outreq->param_hdr.length) - sizeof(*outreq)) /
+		       sizeof(__u16);
 
 		if (result == SCTP_STRRESET_PERFORMED) {
 			if (nums) {
@@ -956,7 +1001,8 @@ struct sctp_chunk *sctp_process_strreset_resp(
 
 		inreq = (struct sctp_strreset_inreq *)req;
 		str_p = inreq->list_of_streams;
-		nums = (ntohs(inreq->param_hdr.length) - sizeof(*inreq)) / 2;
+		nums = (ntohs(inreq->param_hdr.length) - sizeof(*inreq)) /
+		       sizeof(__u16);
 
 		*evp = sctp_ulpevent_make_stream_reset_event(asoc, flags,
 			nums, str_p, GFP_ATOMIC);
@@ -975,6 +1021,7 @@ struct sctp_chunk *sctp_process_strreset_resp(
 		if (result == SCTP_STRRESET_PERFORMED) {
 			__u32 mtsn = sctp_tsnmap_get_max_tsn_seen(
 						&asoc->peer.tsn_map);
+			LIST_HEAD(temp);
 
 			sctp_ulpq_reasm_flushtsn(&asoc->ulpq, mtsn);
 			sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
@@ -983,7 +1030,13 @@ struct sctp_chunk *sctp_process_strreset_resp(
 					 SCTP_TSN_MAP_INITIAL,
 					 stsn, GFP_ATOMIC);
 
+			/* Clean up sacked and abandoned queues only. As the
+			 * out_chunk_list may not be empty, splice it to temp,
+			 * then get it back after sctp_outq_free is done.
+			 */
+			list_splice_init(&asoc->outqueue.out_chunk_list, &temp);
 			sctp_outq_free(&asoc->outqueue);
+			list_splice_init(&temp, &asoc->outqueue.out_chunk_list);
 
 			asoc->next_tsn = rtsn;
 			asoc->ctsn_ack_point = asoc->next_tsn - 1;