tipc: fix lost member events bug

Group messages are not supposed to be returned to sender when the
destination socket disappears. This is done correctly for regular
traffic messages, by setting the 'dest_droppable' bit in the header.
But we forget to do that in group protocol messages. This has the effect
that such messages may sometimes bounce back to the sender, be perceived
as a legitimate peer message, and wreak general havoc for the rest of
the session. In particular, we have seen that a member in state LEAVING
may go back to state RECLAIMED or REMITTED, hence causing suppression
of an otherwise expected 'member down' event to the user.

We fix this by setting the 'dest_droppable' bit even in group protocol
messages.

Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/tipc/group.c b/net/tipc/group.c
index 95fec2c057d6ebdb223e19ef83bf9c383cb2156e..efb5714e7a85c601a9a5440496e6b9413454a681 100644 (file)
--- a/net/tipc/group.c
+++ b/net/tipc/group.c
@@ -648,6 +648,7 @@ static void tipc_group_proto_xmit(struct tipc_group *grp, struct tipc_member *m,
        } else if (mtyp == GRP_REMIT_MSG) {
                msg_set_grp_remitted(hdr, m->window);
        }
+       msg_set_dest_droppable(hdr, true);
        __skb_queue_tail(xmitq, skb);
 }