Hi, On Tue, Jul 07, 2026 at 11:10:45AM +0200, Eric Woudstra wrote: > Edit nft_flow_offload_eval() to make it possible to handle a flowtable of > the nft bridge family. > > Use nft_flow_offload_bridge_init() to fill the flow tuples. It uses > nft_dev_fill_bridge_path() in each direction.
I decided to add a bit more boiler plate in my proposal to detach the inet and bridge flowtable dataplanes. More comments below. > Signed-off-by: Eric Woudstra <[email protected]> > --- > include/net/netfilter/nf_flow_table.h | 5 + > net/netfilter/nf_flow_table_path.c | 126 ++++++++++++++++++++++++++ > net/netfilter/nft_flow_offload.c | 20 +++- > 3 files changed, 146 insertions(+), 5 deletions(-) > > diff --git a/include/net/netfilter/nf_flow_table.h > b/include/net/netfilter/nf_flow_table.h > index 5c6e3b65ae85b..a109eda5250c7 100644 > --- a/include/net/netfilter/nf_flow_table.h > +++ b/include/net/netfilter/nf_flow_table.h > @@ -305,6 +305,11 @@ nf_flow_table_offload_del_cb(struct nf_flowtable > *flow_table, > void flow_offload_route_init(struct flow_offload *flow, > struct nf_flow_route *route); > > +int flow_offload_bridge_init(struct flow_offload *flow, > + const struct nft_pktinfo *pkt, > + enum ip_conntrack_dir dir, > + struct nft_flowtable *ft); > + > int flow_offload_add(struct nf_flowtable *flow_table, struct flow_offload > *flow); > void flow_offload_refresh(struct nf_flowtable *flow_table, > struct flow_offload *flow, bool force); > diff --git a/net/netfilter/nf_flow_table_path.c > b/net/netfilter/nf_flow_table_path.c > index 2b6ebb594a9ee..cdd6a822cb811 100644 > --- a/net/netfilter/nf_flow_table_path.c > +++ b/net/netfilter/nf_flow_table_path.c > @@ -1,6 +1,7 @@ > // SPDX-License-Identifier: GPL-2.0-only > #include <linux/kernel.h> > #include <linux/module.h> > +#include <linux/if_vlan.h> > #include <linux/init.h> > #include <linux/etherdevice.h> > #include <linux/netlink.h> > @@ -365,3 +366,128 @@ int nft_flow_route(const struct nft_pktinfo *pkt, const > struct nf_conn *ct, > return -ENOENT; > } > EXPORT_SYMBOL_GPL(nft_flow_route); > + > +static int nft_dev_fill_bridge_path(struct flow_offload *flow, > + struct nft_flowtable *ft, > + enum ip_conntrack_dir dir, > + const struct net_device *src_dev, > + const struct net_device *dst_dev, > + unsigned char *src_ha, > + unsigned char *dst_ha) > +{ > + struct flow_offload_tuple_rhash *th = flow->tuplehash; > + struct net_device_path_ctx ctx = {}; > + struct net_device_path_stack stack; > + struct nft_forward_info info = {}; > + int i, j = 0; > + > + for (i = th[dir].tuple.encap_num - 1; i >= 0 ; i--) { > + if (info.num_encaps >= NF_FLOW_TABLE_ENCAP_MAX) > + return -1; > + > + if (th[dir].tuple.in_vlan_ingress & BIT(i)) > + continue; > + > + info.encap[info.num_encaps].id = th[dir].tuple.encap[i].id; > + info.encap[info.num_encaps].proto = > th[dir].tuple.encap[i].proto; > + info.num_encaps++; > + > + if (th[dir].tuple.encap[i].proto == htons(ETH_P_PPP_SES)) > + continue; > + > + if (ctx.num_vlans >= NET_DEVICE_PATH_VLAN_MAX) > + return -1; > + ctx.vlan[ctx.num_vlans].id = th[dir].tuple.encap[i].id; > + ctx.vlan[ctx.num_vlans].proto = th[dir].tuple.encap[i].proto; > + ctx.num_vlans++; > + } I am not sure why this is needed, in my approach I simplified this, but maybe I broke bridge vlan filtering. I am not sure what test coverage you made. > + ctx.dev = src_dev; > + ether_addr_copy(ctx.daddr, dst_ha); > + > + if (dev_fill_bridge_path(&ctx, &stack) < 0) > + return -1; > + > + nft_dev_path_info(&stack, &info, dst_ha, &ft->data); > + > + if (!info.indev || info.indev != dst_dev) > + return -1; > + > + th[!dir].tuple.iifidx = info.indev->ifindex; > + for (i = info.num_encaps - 1; i >= 0; i--) { > + th[!dir].tuple.encap[j].id = info.encap[i].id; > + th[!dir].tuple.encap[j].proto = info.encap[i].proto; > + if (info.ingress_vlans & BIT(i)) > + th[!dir].tuple.in_vlan_ingress |= BIT(j); > + j++; > + } > + th[!dir].tuple.encap_num = info.num_encaps; > + > + th[dir].tuple.mtu = dst_dev->mtu; > + ether_addr_copy(th[dir].tuple.out.h_source, src_ha); > + ether_addr_copy(th[dir].tuple.out.h_dest, dst_ha); > + th[dir].tuple.out.ifidx = info.outdev->ifindex; > + th[dir].tuple.xmit_type = FLOW_OFFLOAD_XMIT_DIRECT; > + > + return 0; > +} > + > +int flow_offload_bridge_init(struct flow_offload *flow, > + const struct nft_pktinfo *pkt, > + enum ip_conntrack_dir dir, > + struct nft_flowtable *ft) > +{ > + const struct net_device *in_dev, *out_dev; > + struct ethhdr *eth = eth_hdr(pkt->skb); > + struct flow_offload_tuple *tuple; > + int err, i = 0; > + > + in_dev = nft_in(pkt); > + if (!in_dev || !nft_flowtable_find_dev(in_dev, ft)) > + return -1; > + > + out_dev = nft_out(pkt); > + if (!out_dev || !nft_flowtable_find_dev(out_dev, ft)) > + return -1; > + > + tuple = &flow->tuplehash[!dir].tuple; > + > + if (skb_vlan_tag_present(pkt->skb)) { > + tuple->encap[i].id = skb_vlan_tag_get(pkt->skb); > + tuple->encap[i].proto = pkt->skb->vlan_proto; > + i++; > + } > + > + switch (eth_hdr(pkt->skb)->h_proto) { > + case htons(ETH_P_8021Q): { > + struct vlan_hdr *vhdr = (struct vlan_hdr > *)(skb_mac_header(pkt->skb) > + + sizeof(struct ethhdr)); > + tuple->encap[i].id = ntohs(vhdr->h_vlan_TCI); > + tuple->encap[i].proto = htons(ETH_P_8021Q); > + i++; > + break; > + } > + case htons(ETH_P_PPP_SES): { > + struct pppoe_hdr *phdr = (struct pppoe_hdr > *)(skb_mac_header(pkt->skb) > + + sizeof(struct ethhdr)); > + > + tuple->encap[i].id = ntohs(phdr->sid); > + tuple->encap[i].proto = htons(ETH_P_PPP_SES); > + i++; > + break; > + } > + } > + tuple->encap_num = i; I am not sure these lines above can work. The VLAN tag might be already gone by when the packet is observed from the bridge/forward hook. I think populating the encap fields of the tuple by using the observed packet is not good to go. > + err = nft_dev_fill_bridge_path(flow, ft, !dir, out_dev, in_dev, > + eth->h_dest, eth->h_source); > + if (err < 0) > + return err; > + > + err = nft_dev_fill_bridge_path(flow, ft, dir, in_dev, out_dev, > + eth->h_source, eth->h_dest); > + if (err < 0) > + return err; > + > + return 0; > +} > +EXPORT_SYMBOL_GPL(flow_offload_bridge_init); > diff --git a/net/netfilter/nft_flow_offload.c > b/net/netfilter/nft_flow_offload.c > index 0be62841155b6..d0d63ef7cecd5 100644 > --- a/net/netfilter/nft_flow_offload.c > +++ b/net/netfilter/nft_flow_offload.c > @@ -53,6 +53,7 @@ static void nft_flow_offload_eval(const struct nft_expr > *expr, > { > struct nft_flow_offload *priv = nft_expr_priv(expr); > struct nf_flowtable *flowtable = &priv->flowtable->data; > + bool routing = flowtable->type->family != NFPROTO_BRIDGE; > struct tcphdr _tcph, *tcph = NULL; > struct nf_flow_route route = {}; > enum ip_conntrack_info ctinfo; > @@ -109,14 +110,21 @@ static void nft_flow_offload_eval(const struct nft_expr > *expr, > goto out; > > dir = CTINFO2DIR(ctinfo); > - if (nft_flow_route(pkt, ct, &route, dir, priv->flowtable) < 0) > - goto err_flow_route; > + if (routing) { > + if (nft_flow_route(pkt, ct, &route, dir, priv->flowtable) < 0) > + goto err_flow_route; > + } As said, I am leaning towards adding a bit more boilerplate code to separate the bridge and inet flowtable datapaths. > flow = flow_offload_alloc(ct); > if (!flow) > goto err_flow_alloc; > > - flow_offload_route_init(flow, &route); > + if (routing) > + flow_offload_route_init(flow, &route); > + else > + if (flow_offload_bridge_init(flow, pkt, dir, priv->flowtable) < > 0) > + goto err_flow_add; > + > if (tcph) > flow_offload_ct_tcp(ct); > > @@ -164,8 +172,10 @@ static void nft_flow_offload_eval(const struct nft_expr > *expr, > err_flow_add: > flow_offload_free(flow); > err_flow_alloc: > - dst_release(route.tuple[dir].dst); > - dst_release(route.tuple[!dir].dst); > + if (routing) { > + dst_release(route.tuple[dir].dst); > + dst_release(route.tuple[!dir].dst); > + } > err_flow_route: > clear_bit(IPS_OFFLOAD_BIT, &ct->status); > out: > -- > 2.53.0 >
