[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, 22 insertions, 0 deletions

diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c
index 505c7de10c50..475bfb4972d9 100644
--- a/net/sctp/sm_statefuns.c
+++ b/net/sctp/sm_statefuns.c
@@ -5160,6 +5160,8 @@ static int sctp_eat_data(const struct sctp_association *asoc,
         sctp_verb_t deliver;
         int tmp;
         __u32 tsn;
+        int account_value;
+        struct sock *sk = asoc->base.sk;
 
         data_hdr = chunk->subh.data_hdr = (sctp_datahdr_t *)chunk->skb->data;
         skb_pull(chunk->skb, sizeof(sctp_datahdr_t));
@@ -5169,6 +5171,26 @@ static int sctp_eat_data(const struct sctp_association *asoc,
 
         /* ASSERT:  Now skb->data is really the user data.  */
 
+        /*
+         * if we are established, and we have used up our receive
+         * buffer memory, drop the frame
+         */
+        if (asoc->state == SCTP_STATE_ESTABLISHED) {
+                /*
+                 * If the receive buffer policy is 1, then each
+                 * association can allocate up to sk_rcvbuf bytes
+                 * otherwise, all the associations in aggregate
+                 * may allocate up to sk_rcvbuf bytes
+                 */
+                if (asoc->ep->rcvbuf_policy)
+                        account_value = atomic_read(&asoc->rmem_alloc);
+                else
+                        account_value = atomic_read(&sk->sk_rmem_alloc);
+
+                if (account_value > sk->sk_rcvbuf)
+                        return SCTP_IERROR_IGNORE_TSN;
+        }
+
         /* Process ECN based congestion.
          *
          * Since the chunk structure is reused for all chunks within