[bpf-next V1-RFC PATCH 13/14] bpf: finally expose xdp_rxq_info to XDP bpf-programs
From: Jesper Dangaard Brouer <hidden>
Date: 2017-12-13 11:20:28
Subsystem:
bpf [general] (safe dynamic programs and tools), bpf [networking] (tcx & tc bpf, sock_addr), networking [general], the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Martin KaFai Lau, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
Now all XDP driver have been updated to setup xdp_rxq_info and assign this to xdp_buff->rxq. Thus, it is now safe to enable access to some of the xdp_rxq_info struct members. This patch extend xdp_md and expose UAPI to userspace for ingress_ifindex and rx_queue_index. Access happens via bpf instruction rewrite, that load data directly from struct xdp_rxq_info. * ingress_ifindex map to xdp_rxq_info->dev->ifindex * rx_queue_index map to xdp_rxq_info->queue_index Signed-off-by: Jesper Dangaard Brouer <redacted> --- include/uapi/linux/bpf.h | 3 +++ net/core/filter.c | 19 +++++++++++++++++++ 2 files changed, 22 insertions(+)
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 595bda120cfb..512d456dc469 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h@@ -893,6 +893,9 @@ struct xdp_md { __u32 data; __u32 data_end; __u32 data_meta; + /* Below access go though struct xdp_rxq_info */ + __u32 ingress_ifindex; /* rxq->dev->ifindex */ + __u32 rx_queue_index; /* rxq->queue_index */ }; enum sk_action {
diff --git a/net/core/filter.c b/net/core/filter.c
index 754abe1041b7..676ee9860019 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c@@ -4303,6 +4303,25 @@ static u32 xdp_convert_ctx_access(enum bpf_access_type type, si->dst_reg, si->src_reg, offsetof(struct xdp_buff, data_end)); break; + case offsetof(struct xdp_md, ingress_ifindex): + *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct xdp_buff, rxq), + si->dst_reg, si->src_reg, + offsetof(struct xdp_buff, rxq)); + *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct xdp_rxq_info, dev), + si->dst_reg, si->dst_reg, + offsetof(struct xdp_rxq_info, dev)); + *insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->dst_reg, + bpf_target_off(struct net_device, + ifindex, 4, target_size)); + break; + case offsetof(struct xdp_md, rx_queue_index): + *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct xdp_buff, rxq), + si->dst_reg, si->src_reg, + offsetof(struct xdp_buff, rxq)); + *insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->dst_reg, + bpf_target_off(struct xdp_rxq_info, + queue_index, 4, target_size)); + break; } return insn - insn_buf;