[NETFILTER]: ctnetlink: avoid unneccessary event message generation
Avoid unneccessary event message generation by checking for netlink
listeners before building a message.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/netfilter/ip_conntrack_netlink.c b/net/ipv4/netfilter/ip_conntrack_netlink.c
index e0b5926..5ce2e3f 100644
--- a/net/ipv4/netfilter/ip_conntrack_netlink.c
+++ b/net/ipv4/netfilter/ip_conntrack_netlink.c
@@ -327,9 +327,10 @@
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 aef3cb4..5eadf00 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -338,9 +338,10 @@
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 f6063e8..b88e82a 100644
--- a/net/netfilter/nfnetlink.c
+++ b/net/netfilter/nfnetlink.c
@@ -191,6 +191,12 @@
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;