3 files changed, 14 insertions, 6 deletions
diff --git a/net/ipv4/netfilter/ip_conntrack_netlink.c b/net/ipv4/netfilter/ip_conntrack_netlink.c
index e0b5926c76f9..5ce2e3fc2c7f 100644
--- a/net/ipv4/netfilter/ip_conntrack_netlink.c
+++ b/net/ipv4/netfilter/ip_conntrack_netlink.c
@@ -327,9 +327,10 @@ static int ctnetlink_conntrack_event(struct notifier_block *this,
 		group = NFNLGRP_CONNTRACK_UPDATE;
 	} else 
 		return NOTIFY_DONE;
-	
-  /* FIXME: Check if there are any listeners before, don't hurt performance */
-	
+
+	if (!nfnetlink_has_listeners(group))
+		return NOTIFY_DONE;
+
 	skb = alloc_skb(NLMSG_GOODSIZE, GFP_ATOMIC);
 	if (!skb)
 		return NOTIFY_DONE;
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index aef3cb41131f..5eadf009bb15 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -338,9 +338,10 @@ static int ctnetlink_conntrack_event(struct notifier_block *this,
 		group = NFNLGRP_CONNTRACK_UPDATE;
 	} else
 		return NOTIFY_DONE;
-	
-  /* FIXME: Check if there are any listeners before, don't hurt performance */
-	
+
+	if (!nfnetlink_has_listeners(group))
+		return NOTIFY_DONE;
+
 	skb = alloc_skb(NLMSG_GOODSIZE, GFP_ATOMIC);
 	if (!skb)
 		return NOTIFY_DONE;
diff --git a/net/netfilter/nfnetlink.c b/net/netfilter/nfnetlink.c
index f6063e8f0050..b88e82a1a987 100644
--- a/net/netfilter/nfnetlink.c
+++ b/net/netfilter/nfnetlink.c
@@ -191,6 +191,12 @@ nfnetlink_check_attributes(struct nfnetlink_subsystem *subsys,
         return 0;
 }
 
+int nfnetlink_has_listeners(unsigned int group)
+{
+	return netlink_has_listeners(nfnl, group);
+}
+EXPORT_SYMBOL_GPL(nfnetlink_has_listeners);
+
 int nfnetlink_send(struct sk_buff *skb, u32 pid, unsigned group, int echo)
 {
 	gfp_t allocation = in_interrupt() ? GFP_ATOMIC : GFP_KERNEL;