[PATCH nf-next 3/6] netfilter: nf_tables: disable old tracing if listener is present

[Florian Westphal <fw@strlen.de>]

No need to clutter nflog/dmesg ring buffer with the old tracing output
when the 'native' nfnetlink interface is used.

Signed-off-by: Florian Westphal <fw@strlen.de>
---
 net/netfilter/nf_tables_core.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/net/netfilter/nf_tables_core.c b/net/netfilter/nf_tables_core.c
index dabf5ed..69bdd9a 100644
--- a/net/netfilter/nf_tables_core.c
+++ b/net/netfilter/nf_tables_core.c
@@ -55,6 +55,7 @@ static void __nft_trace_packet(const struct nft_pktinfo *pkt,
 		     rulenum);
 }
 
+static bool prefer_native_trace __read_mostly;
 struct static_key nft_trace_enabled __read_mostly;
 EXPORT_SYMBOL_GPL(nft_trace_enabled);
 
@@ -69,7 +70,13 @@ static inline void nft_trace_packet(const struct nft_pktinfo *pkt,
 		if (!pkt->skb->nf_trace)
 			return;
 		nf_tables_trace_notify(pkt, chain, rule, verdict, type);
-		__nft_trace_packet(pkt, chain, rulenum, type);
+		if (prefer_native_trace)
+			return;
+
+		if (nfnetlink_has_listeners(pkt->net, NFNLGRP_NFTABLES))
+			prefer_native_trace = true;
+		else
+			__nft_trace_packet(pkt, chain, rulenum, type);
 	}
 }
 
-- 
2.4.10