Subject: [PATCH v4 net-next 03/13] netfilter: nft_chain_filter: Add bridge double vlan and pppoe

From: Eric Woudstra <[email-masked]>
Date: Tue, 7 Jan 2025 10:05:20 +0100

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

Signed-off-by: Eric Woudstra <[email-masked]>
---
 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 7010541fcca6..91aa3fa43d31 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