[PATCH 08/25] SCTP: Send only 1 window update SACK per message.

Chris Wright
2006-06-27T20:13:49Z

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-stable review patch. If anyone has any objections, please let us know.
------------------

From: Tsutomu Fujii <t-fujii@nb.jp.nec.com>

Right now, every time we increase our rwnd by more then MTU bytes, we
trigger a SACK. When processing large messages, this will generate a
SACK for almost every other SCTP fragment. However since we are freeing
the entire message at the same time, we might as well collapse the SACK
generation to 1.

Signed-off-by: Tsutomu Fujii <t-fujii@nb.jp.nec.com>
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
---

net/sctp/ulpevent.c | 30 ++++++++++++++++++++++++++++--
1 file changed, 28 insertions(+), 2 deletions(-)

--- linux-2.6.17.1.orig/net/sctp/ulpevent.c
+++ linux-2.6.17.1/net/sctp/ulpevent.c
@@ -51,6 +51,8 @@
static void sctp_ulpevent_receive_data(struct sctp_ulpevent *event,
struct sctp_association *asoc);
static void sctp_ulpevent_release_data(struct sctp_ulpevent *event);
+static void sctp_ulpevent_release_frag_data(struct sctp_ulpevent *event);
+

/* Initialize an ULP event from an given skb. */
SCTP_STATIC void sctp_ulpevent_init(struct sctp_ulpevent *event, int msg_flags)
@@ -883,6 +885,7 @@ static void sctp_ulpevent_receive_data(s
static void sctp_ulpevent_release_data(struct sctp_ulpevent *event)
{
struct sk_buff *skb, *frag;
+ unsigned int len;

/* Current stack structures assume that the rcv buffer is
* per socket. For UDP style sockets this is not true as
@@ -892,7 +895,30 @@ static void sctp_ulpevent_release_data(s
*/

skb = sctp_event2skb(event);
- sctp_assoc_rwnd_increase(event->asoc, skb_headlen(skb));
+ len = skb->len;
+
+ if (!skb->data_len)
+ goto done;
+
+ /* Don't forget the fragments. */
+ for (frag = skb_shinfo(skb)->frag_list; frag; frag = frag->next) {
+ /* NOTE: skb_shinfos are recursive. Although IP returns
+ * skb's with only 1 level of fragments, SCTP reassembly can
+ * increase the levels.
+ */
+ sctp_ulpevent_release_frag_data(sctp_skb2event(frag));
+ }
+
+done:
+ sctp_assoc_rwnd_increase(event->asoc, len);
+ sctp_ulpevent_release_owner(event);
+}
+
+static void sctp_ulpevent_release_frag_data(struct sctp_ulpevent *event)
+{
+ struct sk_buff *skb, *frag;
+
+ skb = sctp_event2skb(event);

if (!skb->data_len)
goto done;
@@ -903,7 +929,7 @@ static void sctp_ulpevent_release_data(s
* skb's with only 1 level of fragments, SCTP reassembly can
* increase the levels.
*/
- sctp_ulpevent_release_data(sctp_skb2event(frag));
+ sctp_ulpevent_release_frag_data(sctp_skb2event(frag));
}

done:

--