Re: [PATCH v5 bpf-next 2/3] netfilter: add bpf_xdp_flow_lookup kfunc

Lorenzo Bianconi
2024-06-29T19:57:57Z

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> On 6/14/24 5:40 PM, Lorenzo Bianconi wrote:
> [...]
> > +enum {
> > + NF_BPF_FLOWTABLE_OPTS_SZ = 4,
> > +};
> > +
> > +__diag_push();
> > +__diag_ignore_all("-Wmissing-prototypes",
> > + "Global functions as their definitions will be in nf_flow_table BTF");
>
> nit: __bpf_kfunc_start_defs();

ack, I will fix it in v6.

>
> > +static struct flow_offload_tuple_rhash *
> > +bpf_xdp_flow_tuple_lookup(struct net_device *dev,
> > + struct flow_offload_tuple *tuple, __be16 proto)
> > +{
> > + struct flow_offload_tuple_rhash *tuplehash;
> > + struct nf_flowtable *nf_flow_table;
> > + struct flow_offload *nf_flow;
> > +
> > + nf_flow_table = nf_flowtable_by_dev(dev);
> > + if (!nf_flow_table)
> > + return ERR_PTR(-ENOENT);
> > +
> > + tuplehash = flow_offload_lookup(nf_flow_table, tuple);
> > + if (!tuplehash)
> > + return ERR_PTR(-ENOENT);
> > +
> > + nf_flow = container_of(tuplehash, struct flow_offload,
> > + tuplehash[tuplehash->tuple.dir]);
> > + flow_offload_refresh(nf_flow_table, nf_flow, false);
> > +
> > + return tuplehash;
> > +}
> > +
> > +__bpf_kfunc struct flow_offload_tuple_rhash *
> > +bpf_xdp_flow_lookup(struct xdp_md *ctx, struct bpf_fib_lookup *fib_tuple,
> > + struct bpf_flowtable_opts *opts, u32 opts_len)
> > +{
> > + struct xdp_buff *xdp = (struct xdp_buff *)ctx;
> > + struct flow_offload_tuple tuple = {
> > + .iifidx = fib_tuple->ifindex,
> > + .l3proto = fib_tuple->family,
> > + .l4proto = fib_tuple->l4_protocol,
> > + .src_port = fib_tuple->sport,
> > + .dst_port = fib_tuple->dport,
> > + };
> > + struct flow_offload_tuple_rhash *tuplehash;
> > + __be16 proto;
> > +
> > + if (opts_len != NF_BPF_FLOWTABLE_OPTS_SZ) {
> > + opts->error = -EINVAL;
> > + return NULL;
> > + }
> > +
> > + switch (fib_tuple->family) {
> > + case AF_INET:
> > + tuple.src_v4.s_addr = fib_tuple->ipv4_src;
> > + tuple.dst_v4.s_addr = fib_tuple->ipv4_dst;
> > + proto = htons(ETH_P_IP);
> > + break;
> > + case AF_INET6:
> > + tuple.src_v6 = *(struct in6_addr *)&fib_tuple->ipv6_src;
> > + tuple.dst_v6 = *(struct in6_addr *)&fib_tuple->ipv6_dst;
> > + proto = htons(ETH_P_IPV6);
> > + break;
> > + default:
> > + opts->error = -EAFNOSUPPORT;
> > + return NULL;
> > + }
> > +
> > + tuplehash = bpf_xdp_flow_tuple_lookup(xdp->rxq->dev, &tuple, proto);
> > + if (IS_ERR(tuplehash)) {
> > + opts->error = PTR_ERR(tuplehash);
> > + return NULL;
> > + }
> > +
> > + return tuplehash;
> > +}
> > +
> > +__diag_pop()
>
> __bpf_kfunc_end_defs();

ack, I will fix it in v6.

Regards,
Lorenzo

>
> Otherwise LGTM!

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