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Diffstat (limited to 'net/sctp/sm_statefuns.c')
-rw-r--r--net/sctp/sm_statefuns.c74
1 files changed, 18 insertions, 56 deletions
diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c
index a583d67cab63..ec0328b1cdb1 100644
--- a/net/sctp/sm_statefuns.c
+++ b/net/sctp/sm_statefuns.c
@@ -5428,10 +5428,8 @@ static int sctp_eat_data(const struct sctp_association *asoc,
sctp_verb_t deliver;
int tmp;
__u32 tsn;
- int account_value;
struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
struct sock *sk = asoc->base.sk;
- int rcvbuf_over = 0;
data_hdr = chunk->subh.data_hdr = (sctp_datahdr_t *)chunk->skb->data;
skb_pull(chunk->skb, sizeof(sctp_datahdr_t));
@@ -5441,48 +5439,6 @@ 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, 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;
- }
- }
-
/* Process ECN based congestion.
*
* Since the chunk structure is reused for all chunks within
@@ -5542,18 +5498,9 @@ static int sctp_eat_data(const struct sctp_association *asoc,
* seems a bit troublesome in that frag_point varies based on
* PMTU. In cases, such as loopback, this might be a rather
* large spill over.
- * NOTE: If we have a full receive buffer here, we only renege if
- * our receiver can still make progress without the tsn being
- * received. We do this because in the event that the associations
- * receive queue is empty we are filling a leading gap, and since
- * reneging moves the gap to the end of the tsn stream, we are likely
- * to stall again very shortly. Avoiding the renege when we fill a
- * leading gap is a good heuristic for avoiding such steady state
- * stalls.
- */
- if (!asoc->rwnd || asoc->rwnd_over ||
- (datalen > asoc->rwnd + asoc->frag_point) ||
- (rcvbuf_over && (!skb_queue_len(&sk->sk_receive_queue)))) {
+ */
+ if ((!chunk->data_accepted) && (!asoc->rwnd || asoc->rwnd_over ||
+ (datalen > asoc->rwnd + asoc->frag_point))) {
/* If this is the next TSN, consider reneging to make
* room. Note: Playing nice with a confused sender. A
@@ -5574,6 +5521,21 @@ static int sctp_eat_data(const struct sctp_association *asoc,
}
/*
+ * Also try to renege to limit our memory usage in the event that
+ * we are under memory pressure
+ * If we can't renege, don't worry about it, the sk_stream_rmem_schedule
+ * in sctp_ulpevent_make_rcvmsg will drop the frame if we grow our
+ * memory usage too much
+ */
+ if (*sk->sk_prot_creator->memory_pressure) {
+ if (sctp_tsnmap_has_gap(map) &&
+ (sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
+ SCTP_DEBUG_PRINTK("Under Pressure! Reneging for tsn:%u\n", tsn);
+ deliver = SCTP_CMD_RENEGE;
+ }
+ }
+
+ /*
* Section 3.3.10.9 No User Data (9)
*
* Cause of error