This patch set introduces new infrastructure for programmatically processing packets in the earliest stages of rx, as part of an effort others are calling Express Data Path (XDP) [1]. Start this effort by introducing a new bpf program type for early packet filtering, before even an skb has been allocated.
With this, hope to enable line rate filtering, with this initial implementation providing drop/allow action only. Patch 1 introduces the new prog type and helpers for validating the bpf program. A new userspace struct is defined containing only len as a field, with others to follow in the future. In patch 2, create a new ndo to pass the fd to support drivers. In patch 3, expose a new rtnl option to userspace. In patch 4, enable support in mlx4 driver. No skb allocation is required, instead a static percpu skb is kept in the driver and minimally initialized for each driver frag. In patch 5, create a sample drop and count program. With single core, achieved ~14.5 Mpps drop rate on a 40G mlx4. This includes packet data access, bpf array lookup, and increment. Interestingly, accessing packet data from the program did not have a noticeable impact on performance. Even so, future enhancements to prefetching / batching / page-allocs should hopefully improve the performance in this path. [1] https://github.com/iovisor/bpf-docs/blob/master/Express_Data_Path.pdf Brenden Blanco (5): bpf: add PHYS_DEV prog type for early driver filter net: add ndo to set bpf prog in adapter rx rtnl: add option for setting link bpf prog mlx4: add support for fast rx drop bpf program Add sample for adding simple drop program to link drivers/net/ethernet/mellanox/mlx4/en_netdev.c | 61 ++++++++++ drivers/net/ethernet/mellanox/mlx4/en_rx.c | 18 +++ drivers/net/ethernet/mellanox/mlx4/mlx4_en.h | 2 + include/linux/netdevice.h | 8 ++ include/uapi/linux/bpf.h | 5 + include/uapi/linux/if_link.h | 1 + kernel/bpf/verifier.c | 1 + net/core/dev.c | 12 ++ net/core/filter.c | 68 +++++++++++ net/core/rtnetlink.c | 10 ++ samples/bpf/Makefile | 4 + samples/bpf/bpf_load.c | 8 ++ samples/bpf/netdrvx1_kern.c | 26 +++++ samples/bpf/netdrvx1_user.c | 155 +++++++++++++++++++++++++ 14 files changed, 379 insertions(+) create mode 100644 samples/bpf/netdrvx1_kern.c create mode 100644 samples/bpf/netdrvx1_user.c -- 2.8.0
