diff options
Diffstat (limited to 'net/sctp/transport.c')
| -rw-r--r-- | net/sctp/transport.c | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/net/sctp/transport.c b/net/sctp/transport.c index 2df29cbdaf5a..9a6cb22d129f 100644 --- a/net/sctp/transport.c +++ b/net/sctp/transport.c @@ -576,6 +576,43 @@ void sctp_transport_lower_cwnd(struct sctp_transport *transport, transport->cwnd, transport->ssthresh); } +/* Apply Max.Burst limit to the congestion window: + * sctpimpguide-05 2.14.2 + * D) When the time comes for the sender to + * transmit new DATA chunks, the protocol parameter Max.Burst MUST + * first be applied to limit how many new DATA chunks may be sent. + * The limit is applied by adjusting cwnd as follows: + * if ((flightsize+ Max.Burst * MTU) < cwnd) + * cwnd = flightsize + Max.Burst * MTU + */ + +void sctp_transport_burst_limited(struct sctp_transport *t) +{ + struct sctp_association *asoc = t->asoc; + u32 old_cwnd = t->cwnd; + u32 max_burst_bytes; + + if (t->burst_limited) + return; + + max_burst_bytes = t->flight_size + (asoc->max_burst * asoc->pathmtu); + if (max_burst_bytes < old_cwnd) { + t->cwnd = max_burst_bytes; + t->burst_limited = old_cwnd; + } +} + +/* Restore the old cwnd congestion window, after the burst had it's + * desired effect. + */ +void sctp_transport_burst_reset(struct sctp_transport *t) +{ + if (t->burst_limited) { + t->cwnd = t->burst_limited; + t->burst_limited = 0; + } +} + /* What is the next timeout value for this transport? */ unsigned long sctp_transport_timeout(struct sctp_transport *t) { @@ -598,6 +635,7 @@ void sctp_transport_reset(struct sctp_transport *t) * (see Section 6.2.1) */ t->cwnd = min(4*asoc->pathmtu, max_t(__u32, 2*asoc->pathmtu, 4380)); + t->burst_limited = 0; t->ssthresh = asoc->peer.i.a_rwnd; t->last_rto = t->rto = asoc->rto_initial; t->rtt = 0; |