[PATCH] net: fix duplicate logs of iptables TRACE target

kai zhang
2022-01-24T06:06:20Z

Below configuration, mangle,filter and security tables have no rule:

There are 5 logs for incoming ssh packet:

kernel: [ 7018.727278] TRACE: raw:PREROUTING:policy:2 IN=enp9s0 ...
kernel: [ 7018.727304] TRACE: mangle:PREROUTING:policy:1 IN=enp9s0 ...
kernel: [ 7018.727327] TRACE: mangle:INPUT:policy:1 IN=enp9s0 ...
kernel: [ 7018.727343] TRACE: filter:INPUT:policy:1 IN=enp9s0 ...
kernel: [ 7018.727359] TRACE: security:INPUT:policy:1 IN=enp9s0 ...

Signed-off-by: kai zhang <zhangkaiheb@126.com>
---
net/ipv4/netfilter/ip_tables.c | 4 +++-
net/ipv6/netfilter/ip6_tables.c | 4 +++-
2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index 2ed7c58b4..5f0e6096e 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -304,9 +304,11 @@ ipt_do_table(void *priv,

#if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE)
/* The packet is traced: log it */
- if (unlikely(skb->nf_trace))
+ if (unlikely(skb->nf_trace)) {
trace_packet(state->net, skb, hook, state->in,
state->out, table->name, private, e);
+ nf_reset_trace(skb);
+ }
#endif
/* Standard target? */
if (!t->u.kernel.target->target) {
diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c
index 2d816277f..ae842a835 100644
--- a/net/ipv6/netfilter/ip6_tables.c
+++ b/net/ipv6/netfilter/ip6_tables.c
@@ -327,9 +327,11 @@ ip6t_do_table(void *priv, struct sk_buff *skb,

#if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE)
/* The packet is traced: log it */
- if (unlikely(skb->nf_trace))
+ if (unlikely(skb->nf_trace)) {
trace_packet(state->net, skb, hook, state->in,
state->out, table->name, private, e);
+ nf_reset_trace(skb);
+ }
#endif
/* Standard target? */
if (!t->u.kernel.target->target) {
--
2.30.2