sctp: implement sender-side procedures for SSN Reset Request Parameter

This patch is to implement sender-side procedures for the Outgoing
and Incoming SSN Reset Request Parameter described in rfc6525 section
5.1.2 and 5.1.3.

It is also add sockopt SCTP_RESET_STREAMS in rfc6525 section 6.3.2
for users.

Note that the new asoc member strreset_outstanding is to make sure
only one reconf request chunk on the fly as rfc6525 section 5.1.1
demands.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 23 insertions, 10 deletions

diff --git a/net/sctp/outqueue.c b/net/sctp/outqueue.c
index 34efaa4ef2f6..65abe22d8691 100644
--- a/net/sctp/outqueue.c
+++ b/net/sctp/outqueue.c
@@ -915,22 +915,28 @@ static void sctp_outq_flush(struct sctp_outq *q, int rtx_timeout, gfp_t gfp)
                 case SCTP_CID_ECN_ECNE:
                 case SCTP_CID_ASCONF:
                 case SCTP_CID_FWD_TSN:
+                case SCTP_CID_RECONF:
                         status = sctp_packet_transmit_chunk(packet, chunk,
                                                             one_packet, gfp);
                         if (status  != SCTP_XMIT_OK) {
                                 /* put the chunk back */
                                 list_add(&chunk->list, &q->control_chunk_list);
-                        } else {
-                                asoc->stats.octrlchunks++;
-                                /* PR-SCTP C5) If a FORWARD TSN is sent, the
-                                 * sender MUST assure that at least one T3-rtx
-                                 * timer is running.
-                                 */
-                                if (chunk->chunk_hdr->type == SCTP_CID_FWD_TSN) {
-                                        sctp_transport_reset_t3_rtx(transport);
-                                        transport->last_time_sent = jiffies;
-                                }
+                                break;
+                        }
+
+                        asoc->stats.octrlchunks++;
+                        /* PR-SCTP C5) If a FORWARD TSN is sent, the
+                         * sender MUST assure that at least one T3-rtx
+                         * timer is running.
+                         */
+                        if (chunk->chunk_hdr->type == SCTP_CID_FWD_TSN) {
+                                sctp_transport_reset_t3_rtx(transport);
+                                transport->last_time_sent = jiffies;
                         }
+
+                        if (chunk == asoc->strreset_chunk)
+                                sctp_transport_reset_reconf_timer(transport);
+
                         break;
 
                 default:
@@ -1016,6 +1022,8 @@ static void sctp_outq_flush(struct sctp_outq *q, int rtx_timeout, gfp_t gfp)
 
                 /* Finally, transmit new packets.  */
                 while ((chunk = sctp_outq_dequeue_data(q)) != NULL) {
+                        __u32 sid = ntohs(chunk->subh.data_hdr->stream);
+
                         /* RFC 2960 6.5 Every DATA chunk MUST carry a valid
                          * stream identifier.
                          */
@@ -1038,6 +1046,11 @@ static void sctp_outq_flush(struct sctp_outq *q, int rtx_timeout, gfp_t gfp)
                                 continue;
                         }
 
+                        if (asoc->stream->out[sid].state == SCTP_STREAM_CLOSED) {
+                                sctp_outq_head_data(q, chunk);
+                                goto sctp_flush_out;
+                        }
+
                         /* If there is a specified transport, use it.
                          * Otherwise, we want to use the active path.
                          */