On Mon, Mar 25, 2024 at 8:36 PM Jason Xing <kerneljasonxing@xxxxxxxxx> wrote:
>
> From: Jason Xing <kernelxing@xxxxxxxxxxx>
>
> At the beginning in 2009 one patch [1] introduced collecting drop
> counter in nf_conntrack_in() by returning -NF_DROP. Later, another
> patch [2] changed the return value of tcp_packet() which now is
> renamed to nf_conntrack_tcp_packet() from -NF_DROP to NF_DROP. As
> we can see, that -NF_DROP should be corrected.
>
> Similarly, there are other two points where the -NF_DROP is used.
>
> Well, as NF_DROP is equal to 0, inverting NF_DROP makes no sense
> as patch [2] said many years ago.
>
> [1]
> commit 7d1e04598e5e ("netfilter: nf_conntrack: account packets drop by tcp_packet()")
> [2]
> commit ec8d540969da ("netfilter: conntrack: fix dropping packet after l4proto->packet()")
>
> Signed-off-by: Jason Xing <kernelxing@xxxxxxxxxxx>
Hello Pablo,
I don't know how it works in the nf area, so I would like to know the
status of this patch and another one (netfilter: conntrack: dccp: try
not to drop skb in conntrack
)? Is there anything I need to change?
Thanks,
Jason
> ---
> v2
> Link: https://lore.kernel.org/all/20240325031945.15760-1-kerneljasonxing@xxxxxxxxx/
> 1. squash three patches into one
> ---
> net/ipv4/netfilter/iptable_filter.c | 2 +-
> net/ipv6/netfilter/ip6table_filter.c | 2 +-
> net/netfilter/nf_conntrack_core.c | 2 +-
> 3 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/net/ipv4/netfilter/iptable_filter.c b/net/ipv4/netfilter/iptable_filter.c
> index b9062f4552ac..3ab908b74795 100644
> --- a/net/ipv4/netfilter/iptable_filter.c
> +++ b/net/ipv4/netfilter/iptable_filter.c
> @@ -44,7 +44,7 @@ static int iptable_filter_table_init(struct net *net)
> return -ENOMEM;
> /* Entry 1 is the FORWARD hook */
> ((struct ipt_standard *)repl->entries)[1].target.verdict =
> - forward ? -NF_ACCEPT - 1 : -NF_DROP - 1;
> + forward ? -NF_ACCEPT - 1 : NF_DROP - 1;
>
> err = ipt_register_table(net, &packet_filter, repl, filter_ops);
> kfree(repl);
> diff --git a/net/ipv6/netfilter/ip6table_filter.c b/net/ipv6/netfilter/ip6table_filter.c
> index df785ebda0ca..e8992693e14a 100644
> --- a/net/ipv6/netfilter/ip6table_filter.c
> +++ b/net/ipv6/netfilter/ip6table_filter.c
> @@ -43,7 +43,7 @@ static int ip6table_filter_table_init(struct net *net)
> return -ENOMEM;
> /* Entry 1 is the FORWARD hook */
> ((struct ip6t_standard *)repl->entries)[1].target.verdict =
> - forward ? -NF_ACCEPT - 1 : -NF_DROP - 1;
> + forward ? -NF_ACCEPT - 1 : NF_DROP - 1;
>
> err = ip6t_register_table(net, &packet_filter, repl, filter_ops);
> kfree(repl);
> diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
> index c63868666bd9..6102dc09cdd3 100644
> --- a/net/netfilter/nf_conntrack_core.c
> +++ b/net/netfilter/nf_conntrack_core.c
> @@ -2024,7 +2024,7 @@ nf_conntrack_in(struct sk_buff *skb, const struct nf_hook_state *state)
> goto repeat;
>
> NF_CT_STAT_INC_ATOMIC(state->net, invalid);
> - if (ret == -NF_DROP)
> + if (ret == NF_DROP)
> NF_CT_STAT_INC_ATOMIC(state->net, drop);
>
> ret = -ret;
> --
> 2.37.3
>
