1 files changed, 31 insertions, 5 deletions

diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 6766913a53e6..d3ccf7973c59 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -1384,6 +1384,7 @@ SCTP_STATIC void sctp_close(struct sock *sk, long timeout)
         struct sctp_endpoint *ep;
         struct sctp_association *asoc;
         struct list_head *pos, *temp;
+        unsigned int data_was_unread;
 
         SCTP_DEBUG_PRINTK("sctp_close(sk: 0x%p, timeout:%ld)\n", sk, timeout);
 
@@ -1393,6 +1394,10 @@ SCTP_STATIC void sctp_close(struct sock *sk, long timeout)
 
         ep = sctp_sk(sk)->ep;
 
+        /* Clean up any skbs sitting on the receive queue.  */
+        data_was_unread = sctp_queue_purge_ulpevents(&sk->sk_receive_queue);
+        data_was_unread += sctp_queue_purge_ulpevents(&sctp_sk(sk)->pd_lobby);
+
         /* Walk all associations on an endpoint.  */
         list_for_each_safe(pos, temp, &ep->asocs) {
                 asoc = list_entry(pos, struct sctp_association, asocs);
@@ -1410,7 +1415,9 @@ SCTP_STATIC void sctp_close(struct sock *sk, long timeout)
                         }
                 }
 
-                if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
+                if (data_was_unread || !skb_queue_empty(&asoc->ulpq.lobby) ||
+                    !skb_queue_empty(&asoc->ulpq.reasm) ||
+                    (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime)) {
                         struct sctp_chunk *chunk;
 
                         chunk = sctp_make_abort_user(asoc, NULL, 0);
@@ -1420,10 +1427,6 @@ SCTP_STATIC void sctp_close(struct sock *sk, long timeout)
                         sctp_primitive_SHUTDOWN(asoc, NULL);
         }
 
-        /* Clean up any skbs sitting on the receive queue.  */
-        sctp_queue_purge_ulpevents(&sk->sk_receive_queue);
-        sctp_queue_purge_ulpevents(&sctp_sk(sk)->pd_lobby);
-
         /* On a TCP-style socket, block for at most linger_time if set. */
         if (sctp_style(sk, TCP) && timeout)
                 sctp_wait_for_close(sk, timeout);
@@ -2073,10 +2076,33 @@ 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;
 }