Do not interleave non-fragments when in partial delivery

Hi David

This is a bug fix, but done on top of 2.6.22 tree. I am trying to minimize the amount of conflict this would cause during merge by doing it this way. However, if you would rather keep all the bugfixes in net-2.6, I can do that too, but that _will_ give you conflicts.

-vlad
---

[SCTP] Do not interleave non-fragments when in partial delivery

The way partial delivery is currently implemented, it is possible to interleave a message (either from another stream, or unordered) that is not part of partial delivery process. The only way to this is for a message to not be a fragment and be 'in order' or unordered for a given stream. This will result in bypassing the reassembly/ordering queues where things live during partial delivery, and the message will be delivered to the socket in the middle of partial delivery.

This is a two-fold problem, in that:
1. the app now must check the stream-id and flags which it may not be doing.
2. this clears partial delivery state from the association and results in app communication hanging.

This patch is a band-aid over a much bigger problem in that we don't do stream interleave.

---
 net/sctp/ulpqueue.c |    9 ++++++++-
 1 files changed, 8 insertions(+), 1 deletions(-)

index ae374a9..fb2ec63 100644
@@ -224,7 +224,14 @@ int sctp_ulpq_tail_event(struct sctp_ulpq *ulpq, struct sctp_ulpevent *event)
 		queue = &sk->sk_receive_queue;
 	} else {
 		if (ulpq->pd_mode) {
-			if (event->msg_flags & MSG_NOTIFICATION)
+			/* If the association is in partial delivery, we
+			 * need to finish delivering the partially processed
+			 * packet before passing any other data.  This is
+			 * because we don't truly support stream interleaving.
+			 */
+			if ((event->msg_flags & MSG_NOTIFICATION) ||
+			    (SCTP_DATA_NOT_FRAG ==
+				    (event->msg_flags & SCTP_DATA_FRAG_MASK)))
 				queue = &sctp_sk(sk)->pd_lobby;
 			else {
 				clear_pd = event->msg_flags & MSG_EOR;

1.5.0.3.438.gc49b2

From: Vlad Yasevich <[email protected]>
Date: Wed, 18 Apr 2007 14:38:15 -0400

I've already determined that I'm destined to deal with tons of conclicts anyways :-)

I'll backport this to net-2.6 unless you beat me to it :-)

Thanks!

attached :)

-vlad

From: Vlad Yasevich <[email protected]>
Date: Wed, 18 Apr 2007 16:48:24 -0400
Subject: [PATCH] [SCTP] Do not interleave non-fragments when in partial delivery

The way partial delivery is currently implemnted, it is possible to intereleave a message (either from another steram, or unordered) that is not part of partial delivery process. The only way to this is for a message to not be a fragment and be 'in order' or unorderd for a given stream. This will result in bypassing the reassembly/ordering queues where things live duing partial delivery, and the message will be delivered to the socket in the middle of partial delivery.

This is a two-fold problem, in that:
1. the app now must check the stream-id and flags which it may not be doing.
2. this clearing partial delivery state from the association and results in ulp hanging.

This patch is a band-aid over a much bigger problem in that we don't do stream interleave.

---
 net/sctp/ulpqueue.c |    9 ++++++++-
 1 files changed, 8 insertions(+), 1 deletions(-)

index bfb197e..b29e3e4 100644
@@ -190,7 +190,14 @@ int sctp_ulpq_tail_event(struct sctp_ulpq *ulpq, struct sctp_ulpevent *event)
 	if (!sctp_sk(sk)->pd_mode) {
 		queue = &sk->sk_receive_queue;
 	} else if (ulpq->pd_mode) {
-		if (event->msg_flags & MSG_NOTIFICATION)
+		/* If the association is in partial delivery, we
+		 * need to finish delivering the partially processed
+		 * packet before passing any other data.  This is
+		 * because we don't truly support stream interleaving.
+		 */
+		if ((event->msg_flags & MSG_NOTIFICATION) ||
+		    (SCTP_DATA_NOT_FRAG ==
+			    (event->msg_flags & SCTP_DATA_FRAG_MASK)))
 			queue = &sctp_sk(sk)->pd_lobby;
 		else {
 			clear_pd = event->msg_flags & MSG_EOR;

1.5.0.3.438.gc49b2

From: Vlad Yasevich <[email protected]>
Date: Wed, 18 Apr 2007 16:52:26 -0400

Thanks a lot, applied.