[SCTP]: Remove temporary associations from backlog and hash.

Every time SCTP creates a temporary association, the stack hashes it,
puts it on a list of endpoint associations and increments the backlog.
However, the lifetime of a temporary association is the processing time
of a current packet and it's destroyed after that. In fact, we don't
really want anyone else finding this association. There is no reason to
do this extra work.

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>

net/sctp/endpointola.c

@@ -144,6 +144,13 @@ void sctp_endpoint_add_asoc(struct sctp_endpoint *ep,
 {
 	struct sock *sk = ep->base.sk;
 
+	/* If this is a temporary association, don't bother
+	 * since we'll be removing it shortly and don't
+	 * want anyone to find it anyway.
+	 */
+	if (asoc->temp)
+		return;
+
 	/* Now just add it to our list of asocs */
 	list_add_tail(&asoc->asocs, &ep->asocs);