[PATCH] For for each TSN t being newly acked (Not only cumulatively, but also SELECTIVELY) cacc_saw_newack should be set to 1.

From: Chang Xiangzhong
Date: Tue Oct 15 2013 - 12:59:18 EST


Signed-off-by: Xiangzhong Chang <changxiangzhong@xxxxxxxxx>
---
net/sctp/outqueue.c | 142 ++++++++++++++++++++++++---------------------------
1 file changed, 68 insertions(+), 74 deletions(-)

diff --git a/net/sctp/outqueue.c b/net/sctp/outqueue.c
index 94df758..f10d848 100644
--- a/net/sctp/outqueue.c
+++ b/net/sctp/outqueue.c
@@ -1357,84 +1357,78 @@ static void sctp_check_transmitted(struct sctp_outq *q,

tsn = ntohl(tchunk->subh.data_hdr->tsn);
if (sctp_acked(sack, tsn)) {
- /* If this queue is the retransmit queue, the
- * retransmit timer has already reclaimed
- * the outstanding bytes for this chunk, so only
- * count bytes associated with a transport.
- */
- if (transport) {
- /* If this chunk is being used for RTT
- * measurement, calculate the RTT and update
- * the RTO using this value.
- *
- * 6.3.1 C5) Karn's algorithm: RTT measurements
- * MUST NOT be made using packets that were
- * retransmitted (and thus for which it is
- * ambiguous whether the reply was for the
- * first instance of the packet or a later
- * instance).
- */
- if (!tchunk->tsn_gap_acked &&
- tchunk->rtt_in_progress) {
- tchunk->rtt_in_progress = 0;
- rtt = jiffies - tchunk->sent_at;
- sctp_transport_update_rto(transport,
- rtt);
- }
- }
-
- /* If the chunk hasn't been marked as ACKED,
- * mark it and account bytes_acked if the
- * chunk had a valid transport (it will not
- * have a transport if ASCONF had deleted it
- * while DATA was outstanding).
- */
if (!tchunk->tsn_gap_acked) {
- tchunk->tsn_gap_acked = 1;
- *highest_new_tsn_in_sack = tsn;
- bytes_acked += sctp_data_size(tchunk);
- if (!tchunk->transport)
- migrate_bytes += sctp_data_size(tchunk);
- forward_progress = true;
+ /* If this queue is the retransmit queue, the
+ * retransmit timer has already reclaimed
+ * the outstanding bytes for this chunk, so only
+ * count bytes associated with a transport.
+ *
+ * If this chunk is being used for RTT
+ * measurement, calculate the RTT and update
+ * the RTO using this value.
+ *
+ * 6.3.1 C5) Karn's algorithm: RTT measurements
+ * MUST NOT be made using packets that were
+ * retransmitted (and thus for which it is
+ * ambiguous whether the reply was for the
+ * first instance of the packet or a later
+ * instance).
+ */
+ if (transport && tchunk->rtt_in_progress) {
+ tchunk->rtt_in_progress = 0;
+ rtt = jiffies - tchunk->sent_at;
+ sctp_transport_update_rto(transport,
+ rtt);
+ }
+
+ /* If the chunk hasn't been marked as ACKED,
+ * mark it and account bytes_acked if the
+ * chunk had a valid transport (it will not
+ * have a transport if ASCONF had deleted it
+ * while DATA was outstanding).
+ */
+ tchunk->tsn_gap_acked = 1;
+ *highest_new_tsn_in_sack = tsn;
+ bytes_acked += sctp_data_size(tchunk);
+ if (!tchunk->transport)
+ migrate_bytes += sctp_data_size(tchunk);
+ forward_progress = true;
+
+ /*
+ * SFR-CACC algorithm:
+ * 2) If the SACK contains gap acks
+ * and the flag CHANGEOVER_ACTIVE is
+ * set the receiver of the SACK MUST
+ * take the following action:
+ *
+ * B) For each TSN t being acked that
+ * has not been acked in any SACK so
+ * far, set cacc_saw_newack to 1 for
+ * the destination that the TSN was
+ * sent to.
+ */
+ if (transport &&
+ sack->num_gap_ack_blocks &&
+ q->asoc->peer.primary_path->cacc.
+ changeover_active)
+ transport->cacc.cacc_saw_newack = 1;
}

if (TSN_lte(tsn, sack_ctsn)) {
- /* RFC 2960 6.3.2 Retransmission Timer Rules
- *
- * R3) Whenever a SACK is received
- * that acknowledges the DATA chunk
- * with the earliest outstanding TSN
- * for that address, restart T3-rtx
- * timer for that address with its
- * current RTO.
- */
- restart_timer = 1;
- forward_progress = true;
-
- if (!tchunk->tsn_gap_acked) {
- /*
- * SFR-CACC algorithm:
- * 2) If the SACK contains gap acks
- * and the flag CHANGEOVER_ACTIVE is
- * set the receiver of the SACK MUST
- * take the following action:
- *
- * B) For each TSN t being acked that
- * has not been acked in any SACK so
- * far, set cacc_saw_newack to 1 for
- * the destination that the TSN was
- * sent to.
- */
- if (transport &&
- sack->num_gap_ack_blocks &&
- q->asoc->peer.primary_path->cacc.
- changeover_active)
- transport->cacc.cacc_saw_newack
- = 1;
- }
-
- list_add_tail(&tchunk->transmitted_list,
- &q->sacked);
+ /* RFC 2960 6.3.2 Retransmission Timer Rules
+ *
+ * R3) Whenever a SACK is received
+ * that acknowledges the DATA chunk
+ * with the earliest outstanding TSN
+ * for that address, restart T3-rtx
+ * timer for that address with its
+ * current RTO.
+ */
+ restart_timer = 1;
+ forward_progress = true;
+
+ list_add_tail(&tchunk->transmitted_list,
+ &q->sacked);
} else {
/* RFC2960 7.2.4, sctpimpguide-05 2.8.2
* M2) Each time a SACK arrives reporting
--
1.7.9.5

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