diff options
Diffstat (limited to 'net/sctp/sm_statefuns.c')
| -rw-r--r-- | net/sctp/sm_statefuns.c | 74 |
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 |