diff options
| -rw-r--r-- | net/sctp/transport.c | 54 |
1 files changed, 33 insertions, 21 deletions
diff --git a/net/sctp/transport.c b/net/sctp/transport.c index 721eeebfcd8a..7cdd6bcddbc5 100644 --- a/net/sctp/transport.c +++ b/net/sctp/transport.c @@ -405,14 +405,6 @@ void sctp_transport_raise_cwnd(struct sctp_transport *transport, TSN_lte(asoc->fast_recovery_exit, sack_ctsn)) asoc->fast_recovery = 0; - /* The appropriate cwnd increase algorithm is performed if, and only - * if the cumulative TSN whould advanced and the congestion window is - * being fully utilized. - */ - if (TSN_lte(sack_ctsn, transport->asoc->ctsn_ack_point) || - (flight_size < cwnd)) - return; - ssthresh = transport->ssthresh; pba = transport->partial_bytes_acked; pmtu = transport->asoc->pathmtu; @@ -435,6 +427,14 @@ void sctp_transport_raise_cwnd(struct sctp_transport *transport, if (asoc->fast_recovery) return; + /* The appropriate cwnd increase algorithm is performed + * if, and only if the congestion window is being fully + * utilized. Note that RFC4960 Errata 3.22 removed the + * other condition on ctsn moving. + */ + if (flight_size < cwnd) + return; + if (bytes_acked > pmtu) cwnd += pmtu; else @@ -446,23 +446,33 @@ void sctp_transport_raise_cwnd(struct sctp_transport *transport, flight_size, pba); } else { /* RFC 2960 7.2.2 Whenever cwnd is greater than ssthresh, - * upon each SACK arrival that advances the Cumulative TSN Ack - * Point, increase partial_bytes_acked by the total number of - * bytes of all new chunks acknowledged in that SACK including - * chunks acknowledged by the new Cumulative TSN Ack and by - * Gap Ack Blocks. + * upon each SACK arrival, increase partial_bytes_acked + * by the total number of bytes of all new chunks + * acknowledged in that SACK including chunks + * acknowledged by the new Cumulative TSN Ack and by Gap + * Ack Blocks. (updated by RFC4960 Errata 3.22) + * + * When partial_bytes_acked is greater than cwnd and + * before the arrival of the SACK the sender had less + * bytes of data outstanding than cwnd (i.e., before + * arrival of the SACK, flightsize was less than cwnd), + * reset partial_bytes_acked to cwnd. (RFC 4960 Errata + * 3.26) * - * When partial_bytes_acked is equal to or greater than cwnd - * and before the arrival of the SACK the sender had cwnd or - * more bytes of data outstanding (i.e., before arrival of the - * SACK, flightsize was greater than or equal to cwnd), - * increase cwnd by MTU, and reset partial_bytes_acked to - * (partial_bytes_acked - cwnd). + * When partial_bytes_acked is equal to or greater than + * cwnd and before the arrival of the SACK the sender + * had cwnd or more bytes of data outstanding (i.e., + * before arrival of the SACK, flightsize was greater + * than or equal to cwnd), partial_bytes_acked is reset + * to (partial_bytes_acked - cwnd). Next, cwnd is + * increased by MTU. (RFC 4960 Errata 3.12) */ pba += bytes_acked; - if (pba >= cwnd) { + if (pba > cwnd && flight_size < cwnd) + pba = cwnd; + if (pba >= cwnd && flight_size >= cwnd) { + pba = pba - cwnd; cwnd += pmtu; - pba = ((cwnd < pba) ? (pba - cwnd) : 0); } pr_debug("%s: congestion avoidance: transport:%p, " @@ -559,6 +569,8 @@ void sctp_transport_lower_cwnd(struct sctp_transport *transport, */ transport->cwnd = max(transport->cwnd/2, 4*asoc->pathmtu); + /* RFC 4960 Errata 3.27.2: also adjust sshthresh */ + transport->ssthresh = transport->cwnd; break; } |