Introduce bpf_xdp_metadata_rx_checksum() kfunc in order to load the HW RX cheksum results in the eBPF program binded to the NIC. Implement xmo_rx_checksum callback for veth and ice drivers.
If the hardware detects a wrong/failed checksum, it will report CHECKSUM_NONE in the packet metadata. Moreover, CHECKSUM_NONE will be returned even if the NIC can't parse the packet (e.g. if it does not support a specific protocol). A possible use case for bpf_xdp_metadata_rx_checksum() would be to implement a XDP DDoS application [1] combining the info from bpf_xdp_metadata_rx_checksum() and bpf_xdp_metadata_rx_hash() kfuncs in order to filter packets with a wrong/failed checksum. [1] https://blog.cloudflare.com/unimog-cloudflares-edge-load-balancer/ --- Changes in v1: - Rebase on top of bpf-next - Test ice driver using xdp_hw_metadata tool available in the bpf kernel selftest - Improve cover letter with an use-case for bpf_xdp_metadata_rx_checksum() - Link to RFC v2: https://lore.kernel.org/r/[email protected] Changes in RFC v2: - Squash patch 1/6 and 2/6 - Introduce enum xdp_checksum definitions - Rework ice support to reuse ice_rx_csum codebase --- Lorenzo Bianconi (5): netlink: specs: Add XDP RX checksum capability to XDP metadata specs net: veth: Add xmo_rx_checksum callback to veth driver net: ice: Add xmo_rx_checksum callback selftests/bpf: Add selftest support for bpf_xdp_metadata_rx_checksum selftests/bpf: Add bpf_xdp_metadata_rx_checksum support to xdp_hw_metadat prog Documentation/netlink/specs/netdev.yaml | 5 + drivers/net/ethernet/intel/ice/ice_txrx_lib.c | 114 +++++++++++++-------- drivers/net/veth.c | 20 ++++ include/net/xdp.h | 14 +++ include/uapi/linux/netdev.h | 3 + net/core/xdp.c | 29 ++++++ tools/include/uapi/linux/netdev.h | 3 + .../selftests/bpf/prog_tests/xdp_metadata.c | 7 ++ .../testing/selftests/bpf/progs/xdp_hw_metadata.c | 7 ++ tools/testing/selftests/bpf/progs/xdp_metadata.c | 1 + tools/testing/selftests/bpf/xdp_hw_metadata.c | 28 +++++ tools/testing/selftests/bpf/xdp_metadata.h | 13 +++ 12 files changed, 204 insertions(+), 40 deletions(-) --- base-commit: db975debcb8c4cd367a78811bc1ba84c83f854bd change-id: 20250925-bpf-xdp-meta-rxcksum-900685e2909d Best regards, -- Lorenzo Bianconi <[email protected]>
