sctp: Fix the RTO-doubling on idle-link heartbeats
SCTP incorrectly doubles rto ever time a Hearbeat chunk
is generated. However RFC 4960 states:
On an idle destination address that is allowed to heartbeat, it is
recommended that a HEARTBEAT chunk is sent once per RTO of that
destination address plus the protocol parameter 'HB.interval', with
jittering of +/- 50% of the RTO value, and exponential backoff of the
RTO if the previous HEARTBEAT is unanswered.
Essentially, of if the heartbean is unacknowledged, do we double the RTO.
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index 9f70d54..23f08fe 100644
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -910,8 +910,10 @@
* should be set. Every time the RTT
* calculation completes (i.e. the DATA chunk
* is SACK'd) clear this flag.
+ * hb_sent : a flag that signals that we have a pending heartbeat.
*/
__u8 rto_pending;
+ __u8 hb_sent;
/* Flag to track the current fast recovery state */
__u8 fast_recovery;