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Commit 02dd3291 authored by Jesper Dangaard Brouer's avatar Jesper Dangaard Brouer Committed by Alexei Starovoitov
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bpf: finally expose xdp_rxq_info to XDP bpf-programs 



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: default avatarJesper Dangaard Brouer <brouer@redhat.com>
Acked-by: default avatarAlexei Starovoitov <ast@kernel.org>
Acked-by: default avatarJohn Fastabend <john.fastabend@gmail.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent e817f856

include/uapi/linux/bpf.h

+3 −0
Original line number Diff line number Diff line
@@ -899,6 +899,9 @@ 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 {

net/core/filter.c

+19 −0
Original line number Diff line number Diff line
@@ -4304,6 +4304,25 @@ 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;