From 17bb652aee5e730f9d9f4c39e450af346418ab6d Mon Sep 17 00:00:00 2001
From: Wei Yongjun <yjwei@cn.fujitsu.com>
Date: Sat, 2 Jul 2011 09:28:04 +0000
Subject: [PATCH] --- yaml --- r: 254690 b: refs/heads/master c:
 949123016a2ef578009b6aa3e98d45d1a154ebfb h: refs/heads/master v: v3

---
 [refs]                  |  2 +-
 trunk/net/sctp/socket.c | 23 +++++++++++++++++++++++
 2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/[refs] b/[refs]
index 675370bed8c9..c31f760ebb32 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: f03d78db65085609938fdb686238867e65003181
+refs/heads/master: 949123016a2ef578009b6aa3e98d45d1a154ebfb
diff --git a/trunk/net/sctp/socket.c b/trunk/net/sctp/socket.c
index 6766913a53e6..08c6238802de 100644
--- a/trunk/net/sctp/socket.c
+++ b/trunk/net/sctp/socket.c
@@ -2073,10 +2073,33 @@ static int sctp_setsockopt_disable_fragments(struct sock *sk,
 static int sctp_setsockopt_events(struct sock *sk, char __user *optval,
 				  unsigned int optlen)
 {
+	struct sctp_association *asoc;
+	struct sctp_ulpevent *event;
+
 	if (optlen > sizeof(struct sctp_event_subscribe))
 		return -EINVAL;
 	if (copy_from_user(&sctp_sk(sk)->subscribe, optval, optlen))
 		return -EFAULT;
+
+	/*
+	 * At the time when a user app subscribes to SCTP_SENDER_DRY_EVENT,
+	 * if there is no data to be sent or retransmit, the stack will
+	 * immediately send up this notification.
+	 */
+	if (sctp_ulpevent_type_enabled(SCTP_SENDER_DRY_EVENT,
+				       &sctp_sk(sk)->subscribe)) {
+		asoc = sctp_id2assoc(sk, 0);
+
+		if (asoc && sctp_outq_is_empty(&asoc->outqueue)) {
+			event = sctp_ulpevent_make_sender_dry_event(asoc,
+					GFP_ATOMIC);
+			if (!event)
+				return -ENOMEM;
+
+			sctp_ulpq_tail_event(&asoc->ulpq, event);
+		}
+	}
+
 	return 0;
 }