[PATCH net] sctp: improve the events for sctp stream adding

[PATCH net] sctp: improve the events for sctp stream adding

[Xin Long]

This patch is to improve sctp stream adding events in 2 places:

  1. In sctp_process_strreset_addstrm_out(), move up SCTP_MAX_STREAM
     and in stream allocation failure checks, as the adding has to
     succeed after reconf_timer stops for the in stream adding
     request retransmission.

  3. In sctp_process_strreset_addstrm_in(), no event should be sent,
     as no in or out stream is added here.

Fixes: 50a41591f110 ("sctp: implement receiver-side procedures for the Add Outgoing Streams Request Parameter")
Fixes: c5c4ebb3ab87 ("sctp: implement receiver-side procedures for the Add Incoming Streams Request Parameter")
Reported-by: Ying Xu <yinxu@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
---
 net/sctp/stream.c | 19 ++++++++-----------
 1 file changed, 8 insertions(+), 11 deletions(-)

diff --git a/net/sctp/stream.c b/net/sctp/stream.c
index 6c188b0..80e0ae5 100644
--- a/net/sctp/stream.c
+++ b/net/sctp/stream.c
@@ -866,6 +866,14 @@ struct sctp_chunk *sctp_process_strreset_addstrm_out(
 	if (!(asoc->strreset_enable & SCTP_ENABLE_CHANGE_ASSOC_REQ))
 		goto out;
 
+	in = ntohs(addstrm->number_of_streams);
+	incnt = stream->incnt + in;
+	if (!in || incnt > SCTP_MAX_STREAM)
+		goto out;
+
+	if (sctp_stream_alloc_in(stream, incnt, GFP_ATOMIC))
+		goto out;
+
 	if (asoc->strreset_chunk) {
 		if (!sctp_chunk_lookup_strreset_param(
 			asoc, 0, SCTP_PARAM_RESET_ADD_IN_STREAMS)) {
@@ -889,14 +897,6 @@ struct sctp_chunk *sctp_process_strreset_addstrm_out(
 		}
 	}
 
-	in = ntohs(addstrm->number_of_streams);
-	incnt = stream->incnt + in;
-	if (!in || incnt > SCTP_MAX_STREAM)
-		goto out;
-
-	if (sctp_stream_alloc_in(stream, incnt, GFP_ATOMIC))
-		goto out;
-
 	stream->incnt = incnt;
 
 	result = SCTP_STRRESET_PERFORMED;
@@ -966,9 +966,6 @@ struct sctp_chunk *sctp_process_strreset_addstrm_in(
 
 	result = SCTP_STRRESET_PERFORMED;
 
-	*evp = sctp_ulpevent_make_stream_change_event(asoc,
-		0, 0, ntohs(addstrm->number_of_streams), GFP_ATOMIC);
-
 out:
 	sctp_update_strreset_result(asoc, result);
 err:
-- 
2.1.0

Re: [PATCH net] sctp: improve the events for sctp stream adding

[David Miller]

From: Xin Long <lucien.xin@gmail.com>
Date: Tue, 22 Jan 2019 02:40:12 +0800

> This patch is to improve sctp stream adding events in 2 places:
> 
>   1. In sctp_process_strreset_addstrm_out(), move up SCTP_MAX_STREAM
>      and in stream allocation failure checks, as the adding has to
>      succeed after reconf_timer stops for the in stream adding
>      request retransmission.
> 
>   3. In sctp_process_strreset_addstrm_in(), no event should be sent,
>      as no in or out stream is added here.
> 
> Fixes: 50a41591f110 ("sctp: implement receiver-side procedures for the Add Outgoing Streams Request Parameter")
> Fixes: c5c4ebb3ab87 ("sctp: implement receiver-side procedures for the Add Incoming Streams Request Parameter")
> Reported-by: Ying Xu <yinxu@redhat.com>
> Signed-off-by: Xin Long <lucien.xin@gmail.com>

Applied and queued up for -stable.