Thread (7 messages) 7 messages, 2 authors, 2026-02-23

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

From: Florian Westphal <fw@strlen.de>
Date: 2026-02-23 19:15:24
Also in: bridge, netfilter-devel

Eric Woudstra [off-list ref] 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.
 
quoted hunk ↗ jump to hunk
Signed-off-by: Eric Woudstra <redacted>
---
 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.
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