netfilter: ctnetlink: fix echo if not subscribed to any multicast group

This patch fixes echoing if the socket that has sent the request to
create/update/delete an entry is not subscribed to any multicast
group. With the current code, ctnetlink would not send the echo
message via unicast as nfnetlink_send() would be skip.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/netfilter/nf_conntrack_netlink.c

@@ -434,7 +434,7 @@ static int ctnetlink_conntrack_event(struct notifier_block *this,
 	} else
 		return NOTIFY_DONE;
 
-	if (!nfnetlink_has_listeners(group))
+	if (!item->report && !nfnetlink_has_listeners(group))
 		return NOTIFY_DONE;
 
 	skb = alloc_skb(NLMSG_GOODSIZE, GFP_ATOMIC);
@@ -1502,7 +1502,8 @@ static int ctnetlink_expect_event(struct notifier_block *this,
 	} else
 		return NOTIFY_DONE;
 
-	if (!nfnetlink_has_listeners(NFNLGRP_CONNTRACK_EXP_NEW))
+	if (!item->report &&
+	    !nfnetlink_has_listeners(NFNLGRP_CONNTRACK_EXP_NEW))
 		return NOTIFY_DONE;
 
 	skb = alloc_skb(NLMSG_GOODSIZE, GFP_ATOMIC);