[PATCH v9 nf 05/15] netfilter: nft_chain_filter: Add bridge double vlan and pppoe

Eric Woudstra
2025-03-05T10:30:11Z

This adds the capability to evaluate 802.1ad, QinQ, PPPoE and PPPoE-in-Q
packets in the bridge filter chain.

Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Eric Woudstra <ericwouds@gmail.com>
---
net/netfilter/nft_chain_filter.c | 20 +++++++++++++++++++-
1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/net/netfilter/nft_chain_filter.c b/net/netfilter/nft_chain_filter.c
index 19a553550c76..7c7080c1a67d 100644
--- a/net/netfilter/nft_chain_filter.c
+++ b/net/netfilter/nft_chain_filter.c
@@ -232,11 +232,27 @@ nft_do_chain_bridge(void *priv,
struct sk_buff *skb,
const struct nf_hook_state *state)
{
+ struct ethhdr *ethh = eth_hdr(skb);
struct nft_pktinfo pkt;
+ int thoff;

nft_set_pktinfo(&pkt, skb, state);

- switch (eth_hdr(skb)->h_proto) {
+ switch (ethh->h_proto) {
+ case htons(ETH_P_PPP_SES):
+ thoff = PPPOE_SES_HLEN;
+ ethh += thoff;
+ break;
+ case htons(ETH_P_8021Q):
+ thoff = VLAN_HLEN;
+ ethh += thoff;
+ break;
+ default:
+ thoff = 0;
+ break;
+ }
+
+ switch (ethh->h_proto) {
case htons(ETH_P_IP):
nft_set_pktinfo_ipv4_validate(&pkt);
break;
@@ -248,6 +264,8 @@ nft_do_chain_bridge(void *priv,
break;
}

+ pkt.thoff += thoff;
+
return nft_do_chain(&pkt, priv);
}

--
2.47.1