[PATCH net 1/1] tipc: don't send FIN message from connectionless socket

[PATCH net 1/1] tipc: don't send FIN message from connectionless socket

[Jon Maloy]

In commit 6f00089c7372 ("tipc: remove SS_DISCONNECTING state") the
check for socket type is in the wrong place, causing a closing socket
to always send out a FIN message even when the socket was never
connected. This is normally harmless, since the destination node for
such messages most often is zero, and the message will be dropped, but
it is still a wrong and confusing behavior.

We fix this in this commit.

Reviewed-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
---
 net/tipc/socket.c | 24 +++++++++++++-----------
 1 file changed, 13 insertions(+), 11 deletions(-)

diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index 333c5da..800caaa 100644
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -441,15 +441,19 @@ static void __tipc_shutdown(struct socket *sock, int error)
 	while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
 		if (TIPC_SKB_CB(skb)->bytes_read) {
 			kfree_skb(skb);
-		} else {
-			if (!tipc_sk_type_connectionless(sk) &&
-			    sk->sk_state != TIPC_DISCONNECTING) {
-				tipc_set_sk_state(sk, TIPC_DISCONNECTING);
-				tipc_node_remove_conn(net, dnode, tsk->portid);
-			}
-			tipc_sk_respond(sk, skb, error);
+			continue;
+		}
+		if (!tipc_sk_type_connectionless(sk) &&
+		    sk->sk_state != TIPC_DISCONNECTING) {
+			tipc_set_sk_state(sk, TIPC_DISCONNECTING);
+			tipc_node_remove_conn(net, dnode, tsk->portid);
 		}
+		tipc_sk_respond(sk, skb, error);
 	}
+
+	if (tipc_sk_type_connectionless(sk))
+		return;
+
 	if (sk->sk_state != TIPC_DISCONNECTING) {
 		skb = tipc_msg_create(TIPC_CRITICAL_IMPORTANCE,
 				      TIPC_CONN_MSG, SHORT_H_SIZE, 0, dnode,
@@ -457,10 +461,8 @@ static void __tipc_shutdown(struct socket *sock, int error)
 				      tsk->portid, error);
 		if (skb)
 			tipc_node_xmit_skb(net, skb, dnode, tsk->portid);
-		if (!tipc_sk_type_connectionless(sk)) {
-			tipc_node_remove_conn(net, dnode, tsk->portid);
-			tipc_set_sk_state(sk, TIPC_DISCONNECTING);
-		}
+		tipc_node_remove_conn(net, dnode, tsk->portid);
+		tipc_set_sk_state(sk, TIPC_DISCONNECTING);
 	}
 }
 
-- 
2.7.4

Re: [PATCH net 1/1] tipc: don't send FIN message from connectionless socket

[David Miller]

From: Jon Maloy <jon.maloy@ericsson.com>
Date: Thu, 22 Dec 2016 07:22:29 -0500

> In commit 6f00089c7372 ("tipc: remove SS_DISCONNECTING state") the
> check for socket type is in the wrong place, causing a closing socket
> to always send out a FIN message even when the socket was never
> connected. This is normally harmless, since the destination node for
> such messages most often is zero, and the message will be dropped, but
> it is still a wrong and confusing behavior.
> 
> We fix this in this commit.
> 
> Reviewed-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>

Applied.

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