Re: [PATCH v18 nf-next 4/4] netfilter: nft_chain_filter: Add bridge double vlan and pppoe

Florian Westphal
2026-02-23T19:15:24Z

Eric Woudstra <ericwouds@gmail.com> wrote:
> In nft_do_chain_bridge() pktinfo is only fully populated for plain packets
> and packets encapsulated in single 802.1q or 802.1ad.
>
> When implementing the software bridge-fastpath and testing all possible
> encapulations, there can be more encapsulations:
>
> The packet could (also) be encapsulated in PPPoE, or the packet could be
> encapsulated in an inner 802.1q, combined with an outer 802.1ad or 802.1q
> encapsulation.
>
> nft_flow_offload_eval() also examines the L4 header, with the L4 protocol
> known from the conntrack-tuplehash. To access the header it uses
> nft_thoff(), but for these packets it returns zero.
>
> Introduce nft_set_bridge_pktinfo() to help populate pktinfo with the
> offsets.

> Signed-off-by: Eric Woudstra <ericwouds@gmail.com>
> ---
> net/netfilter/nft_chain_filter.c | 55 +++++++++++++++++++++++++++++---
> 1 file changed, 51 insertions(+), 4 deletions(-)
>
> diff --git a/net/netfilter/nft_chain_filter.c b/net/netfilter/nft_chain_filter.c
> index d4d5eadaba9c..66ef30c60e56 100644
> --- a/net/netfilter/nft_chain_filter.c
> +++ b/net/netfilter/nft_chain_filter.c
> @@ -227,21 +227,68 @@ static inline void nft_chain_filter_inet_fini(void) {}
> #endif /* CONFIG_NF_TABLES_IPV6 */
>
> #if IS_ENABLED(CONFIG_NF_TABLES_BRIDGE)
> +static int nft_set_bridge_pktinfo(struct nft_pktinfo *pkt, struct sk_buff *skb,
> + const struct nf_hook_state *state,
> + __be16 *proto)
> +{
> + nft_set_pktinfo(pkt, skb, state);
> +
> + switch (*proto) {
> + case htons(ETH_P_PPP_SES): {
> + struct ppp_hdr {
> + struct pppoe_hdr hdr;

Hmm, this seems to trigger warning on NIPAs build_allmodconfig_warn test:

../include/uapi/linux/if_pppox.h:153:29: warning: array of flexible structures

Would you mind a new version? Its the last patch, so I leave it up to
you if you want to resend the whole series or just 4/4.

Sorry, I did not have time to run the entire test pipeline with the
pending patches until today.