[SCTP]: Include sk_buff overhead while updating the peer's receive window.

Currently if the sender is sending small messages, it can cause a receiver
to run out of receive buffer space even when the advertised receive window
is still open and results in packet drops and retransmissions. Including
a overhead while updating the sender's view of peer receive window will
reduce the chances of receive buffer space overshooting the receive window.

Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 1 deletions

diff --git a/net/sctp/outqueue.c b/net/sctp/outqueue.c
index 37074a39ecbb..739582415bf6 100644
--- a/net/sctp/outqueue.c
+++ b/net/sctp/outqueue.c
@@ -416,7 +416,8 @@ void sctp_retransmit_mark(struct sctp_outq *q,
                          * (Section 7.2.4)), add the data size of those
                          * chunks to the rwnd.
                          */
-                        q->asoc->peer.rwnd += sctp_data_size(chunk);
+                        q->asoc->peer.rwnd += (sctp_data_size(chunk) +
+                                                sizeof(struct sk_buff));
                         q->outstanding_bytes -= sctp_data_size(chunk);
                         transport->flight_size -= sctp_data_size(chunk);