Re: [PATCH net-next] netfilter: conntrack: dccp: try not to drop skb in conntrack

[Jason Xing <kerneljasonxing@gmail.com>]

On Fri, Mar 8, 2024 at 5:29 PM Jason Xing <kerneljasonxing@gmail.com> wrote:
>
> From: Jason Xing <kernelxing@tencent.com>
>
> It would be better not to drop skb in conntrack unless we have good
> alternative as Florian said[1]. So we can treat the result of testing
> skb's header pointer as nf_conntrack_tcp_packet() does.
>
> [1]
> Link: https://lore.kernel.org/all/20240307141025.GL4420@breakpoint.cc/
>
> Signed-off-by: Jason Xing <kernelxing@tencent.com>
> ---
>  net/netfilter/nf_conntrack_proto_dccp.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/net/netfilter/nf_conntrack_proto_dccp.c b/net/netfilter/nf_conntrack_proto_dccp.c
> index e2db1f4ec2df..ebc4f733bb2e 100644
> --- a/net/netfilter/nf_conntrack_proto_dccp.c
> +++ b/net/netfilter/nf_conntrack_proto_dccp.c
> @@ -525,7 +525,7 @@ int nf_conntrack_dccp_packet(struct nf_conn *ct, struct sk_buff *skb,
>
>         dh = skb_header_pointer(skb, dataoff, sizeof(*dh), &_dh.dh);
>         if (!dh)
> -               return NF_DROP;
> +               return -NF_ACCEPT;
>
>         if (dccp_error(dh, skb, dataoff, state))
>                 return -NF_ACCEPT;
> @@ -533,7 +533,7 @@ int nf_conntrack_dccp_packet(struct nf_conn *ct, struct sk_buff *skb,
>         /* pull again, including possible 48 bit sequences and subtype header */
>         dh = dccp_header_pointer(skb, dataoff, dh, &_dh);
>         if (!dh)
> -               return NF_DROP;
> +               return -NF_ACCEPT;
>
>         type = dh->dccph_type;
>         if (!nf_ct_is_confirmed(ct) && !dccp_new(ct, skb, dh, state))
> --
> 2.37.3
>

I saw the status in patchwork was changed, but I've not received the
comments. So I spent some time learning how it works in the netfilter
area.

I just noticed that there are two trees (nf and nf-next), so should I
target nf-next and resend this patch and another one[1]?

[1]: https://lore.kernel.org/netfilter-devel/20240308092915.9751-2-kerneljasonxing@gmail.com/T/#m0ced362b380cff7e031d020e906ec2aa00669ce6

Thanks,
Jason