sctp: add stream reconf timer

This patch is to add a per transport timer based on sctp timer frame
for stream reconf chunk retransmission. It would start after sending
a reconf request chunk, and stop after receiving the response chunk.

If the timer expires, besides retransmitting the reconf request chunk,
it would also do the same thing with data RTO timer. like to increase
the appropriate error counts, and perform threshold management, possibly
destroying the asoc if sctp retransmission thresholds are exceeded, just
as section 5.1.1 describes.

This patch is also to add asoc strreset_chunk, it is used to save the
reconf request chunk, so that it can be retransmitted, and to check if
the response is really for this request by comparing the information
inside with the response chunk as well.

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

1 files changed, 15 insertions, 2 deletions

diff --git a/net/sctp/transport.c b/net/sctp/transport.c
index a1652ab63918..baa1ac00d7b5 100644
--- a/net/sctp/transport.c
+++ b/net/sctp/transport.c
@@ -88,9 +88,11 @@ static struct sctp_transport *sctp_transport_init(struct net *net,
 	INIT_LIST_HEAD(&peer->transports);
 
 	setup_timer(&peer->T3_rtx_timer, sctp_generate_t3_rtx_event,
-			(unsigned long)peer);
+		    (unsigned long)peer);
 	setup_timer(&peer->hb_timer, sctp_generate_heartbeat_event,
-			(unsigned long)peer);
+		    (unsigned long)peer);
+	setup_timer(&peer->reconf_timer, sctp_generate_reconf_event,
+		    (unsigned long)peer);
 	setup_timer(&peer->proto_unreach_timer,
 		    sctp_generate_proto_unreach_event, (unsigned long)peer);
 
@@ -144,6 +146,9 @@ void sctp_transport_free(struct sctp_transport *transport)
 	if (del_timer(&transport->T3_rtx_timer))
 		sctp_transport_put(transport);
 
+	if (del_timer(&transport->reconf_timer))
+		sctp_transport_put(transport);
+
 	/* Delete the ICMP proto unreachable timer if it's active. */
 	if (del_timer(&transport->proto_unreach_timer))
 		sctp_association_put(transport->asoc);
@@ -211,6 +216,14 @@ void sctp_transport_reset_hb_timer(struct sctp_transport *transport)
 		sctp_transport_hold(transport);
 }
 
+void sctp_transport_reset_reconf_timer(struct sctp_transport *transport)
+{
+	if (!timer_pending(&transport->reconf_timer))
+		if (!mod_timer(&transport->reconf_timer,
+			       jiffies + transport->rto))
+			sctp_transport_hold(transport);
+}
+
 /* This transport has been assigned to an association.
  * Initialize fields from the association or from the sock itself.
  * Register the reference count in the association.