From 31de4105f00d64570139bc5494a201b0bd57349f Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Fri, 17 Feb 2023 12:55:14 -0800 Subject: bpf: Add BPF_FIB_LOOKUP_SKIP_NEIGH for bpf_fib_lookup The bpf_fib_lookup() also looks up the neigh table. This was done before bpf_redirect_neigh() was added. In the use case that does not manage the neigh table and requires bpf_fib_lookup() to lookup a fib to decide if it needs to redirect or not, the bpf prog can depend only on using bpf_redirect_neigh() to lookup the neigh. It also keeps the neigh entries fresh and connected. This patch adds a bpf_fib_lookup flag, SKIP_NEIGH, to avoid the double neigh lookup when the bpf prog always call bpf_redirect_neigh() to do the neigh lookup. The params->smac output is skipped together when SKIP_NEIGH is set because bpf_redirect_neigh() will figure out the smac also. Signed-off-by: Martin KaFai Lau Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20230217205515.3583372-1-martin.lau@linux.dev --- tools/include/uapi/linux/bpf.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'tools/include/uapi/linux') diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 1503f61336b6..62ce1f5d1b1d 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -3134,6 +3134,11 @@ union bpf_attr { * **BPF_FIB_LOOKUP_OUTPUT** * Perform lookup from an egress perspective (default is * ingress). + * **BPF_FIB_LOOKUP_SKIP_NEIGH** + * Skip the neighbour table lookup. *params*->dmac + * and *params*->smac will not be set as output. A common + * use case is to call **bpf_redirect_neigh**\ () after + * doing **bpf_fib_lookup**\ (). * * *ctx* is either **struct xdp_md** for XDP programs or * **struct sk_buff** tc cls_act programs. @@ -6750,6 +6755,7 @@ struct bpf_raw_tracepoint_args { enum { BPF_FIB_LOOKUP_DIRECT = (1U << 0), BPF_FIB_LOOKUP_OUTPUT = (1U << 1), + BPF_FIB_LOOKUP_SKIP_NEIGH = (1U << 2), }; enum { -- cgit v1.2.3