[SCTP]: Include ulpevents in socket receive buffer accounting.

Also introduces a sysctl option to configure the receive buffer
accounting policy to be either at socket or association level.
Default is all the associations on the same socket share the
receive buffer.

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

1 files changed, 7 insertions, 17 deletions

diff --git a/net/sctp/ulpevent.c b/net/sctp/ulpevent.c
index e049f41faa47..ba97f974f57c 100644
--- a/net/sctp/ulpevent.c
+++ b/net/sctp/ulpevent.c
@@ -52,19 +52,6 @@ static void sctp_ulpevent_receive_data(struct sctp_ulpevent *event,
                                        struct sctp_association *asoc);
 static void sctp_ulpevent_release_data(struct sctp_ulpevent *event);
 
-/* Stub skb destructor.  */
-static void sctp_stub_rfree(struct sk_buff *skb)
-{
-/* WARNING:  This function is just a warning not to use the
- * skb destructor.  If the skb is shared, we may get the destructor
- * callback on some processor that does not own the sock_lock.  This
- * was occuring with PACKET socket applications that were monitoring
- * our skbs.   We can't take the sock_lock, because we can't risk
- * recursing if we do really own the sock lock.  Instead, do all
- * of our rwnd manipulation while we own the sock_lock outright.
- */
-}
-
 /* Initialize an ULP event from an given skb.  */
 SCTP_STATIC void sctp_ulpevent_init(struct sctp_ulpevent *event, int msg_flags)
 {
@@ -111,15 +98,19 @@ static inline void sctp_ulpevent_set_owner(struct sctp_ulpevent *event,
          */
         sctp_association_hold((struct sctp_association *)asoc);
         skb = sctp_event2skb(event);
-        skb->sk = asoc->base.sk;
         event->asoc = (struct sctp_association *)asoc;
-        skb->destructor = sctp_stub_rfree;
+        atomic_add(skb->truesize, &event->asoc->rmem_alloc);
+        skb_set_owner_r(skb, asoc->base.sk);
 }
 
 /* A simple destructor to give up the reference to the association. */
 static inline void sctp_ulpevent_release_owner(struct sctp_ulpevent *event)
 {
-        sctp_association_put(event->asoc);
+        struct sctp_association *asoc = event->asoc;
+        struct sk_buff *skb = sctp_event2skb(event);
+
+        atomic_sub(skb->truesize, &asoc->rmem_alloc);
+        sctp_association_put(asoc);
 }
 
 /* Create and initialize an SCTP_ASSOC_CHANGE event.
@@ -922,7 +913,6 @@ done:
 /* Free a ulpevent that has an owner.  It includes releasing the reference
  * to the owner, updating the rwnd in case of a DATA event and freeing the
  * skb.
- * See comments in sctp_stub_rfree().
  */
 void sctp_ulpevent_free(struct sctp_ulpevent *event)
 {