Based on previous discussion[0], we determined that it would be beneficial to rework bpf_redirect_neigh() so the caller can supply the nexthop information (e.g., from a previous call to bpf_fib_lookup()). This way, the two helpers can be combined without incurring a second FIB lookup to find the nexthop, and bpf_fib_lookup() becomes usable even if no nexthop entry currently exists. This patch (and accompanying selftest update) accomplishes this by way of an optional paramter to bpf_redirect_neigh(). This is an API change, and so should really be merged into the bpf tree to be part of the 5.10 cycle; however, since bpf-next has not yet been merged into bpf, I'm sending this as an RFC against bpf-next for discussion, and will repost against bpf once that merge happens (Daniel, unless you have a better way of doing this, of course). -Toke [0] https://lore.kernel.org/bpf/393e17fc-d187-3a8d-2f0d-a627c7c63fca@xxxxxxxxxxxxx/ --- Toke Høiland-Jørgensen (2): bpf_redirect_neigh: Support supplying the nexthop as a helper parameter selftests: Update test_tc_neigh to use the modified bpf_redirect_neigh() .../selftests/bpf/progs/test_tc_neigh.c | 83 ++++++++++++++++--- .../testing/selftests/bpf/test_tc_redirect.sh | 8 +- 2 files changed, 78 insertions(+), 13 deletions(-)
