- /*
- * If we are established, and we have used up our receive buffer
- * memory, think about droping the frame.
- * Note that we have an opportunity to improve performance here.
- * If we accept one chunk from an skbuff, we have to keep all the
- * memory of that skbuff around until the chunk is read into user
- * space. Therefore, once we accept 1 chunk we may as well accept all
- * remaining chunks in the skbuff. The data_accepted flag helps us do
- * that.
- */
- if ((asoc->state == SCTP_STATE_ESTABLISHED) && (!chunk->data_accepted)) {
- /*
- * 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) {
- /*
- * We need to make forward progress, even when we are
- * under memory pressure, so we always allow the
- * next tsn after the ctsn ack point to be accepted.
- * This lets us avoid deadlocks in which we have to
- * drop frames that would otherwise let us drain the
- * receive queue.
- */
- if ((sctp_tsnmap_get_ctsn(map) + 1) != tsn)
- return SCTP_IERROR_IGNORE_TSN;
-
- /*
- * We're going to accept the frame but we should renege
- * to make space for it. This will send us down that
- * path later in this function.
- */
- rcvbuf_over = 1;
- }
- }
-