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

Jesper Dangaard Brouer committed 8 years ago

Commit 02dd3291 parent e817f852 files · +22 −0Browse files

Unified · Split

2 files

include/uapi/linux/bpf.h +3 −0
net/core/filter.c +19 −0

include/uapi/linux/bpf.h+3−0

@@ -899,6 +899,9 @@ struct xdp_md { · 898 unmodified lines
899	899	__u32 data;
900	900	__u32 data_end;
901	901	__u32 data_meta;
	902	+ /* Below access go though struct xdp_rxq_info */
	903	+ __u32 ingress_ifindex; /* rxq->dev->ifindex */
	904	+ __u32 rx_queue_index; /* rxq->queue_index */
902	905	};
903	906
904	907	enum sk_action {

net/core/filter.c+19−0

@@ -4304,6 +4304,25 @@ static u32 xdp_convert_ctx_access(enum bpf_access_type type, · 4303 unmodified lines
4304	4304	si->dst_reg, si->src_reg,
4305	4305	offsetof(struct xdp_buff, data_end));
4306	4306	break;
	4307	+ case offsetof(struct xdp_md, ingress_ifindex):
	4308	+ *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct xdp_buff, rxq),
	4309	+ si->dst_reg, si->src_reg,
	4310	+ offsetof(struct xdp_buff, rxq));
	4311	+ *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct xdp_rxq_info, dev),
	4312	+ si->dst_reg, si->dst_reg,
	4313	+ offsetof(struct xdp_rxq_info, dev));
	4314	+ *insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->dst_reg,
	4315	+ bpf_target_off(struct net_device,
	4316	+ ifindex, 4, target_size));
	4317	+ break;
	4318	+ case offsetof(struct xdp_md, rx_queue_index):
	4319	+ *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct xdp_buff, rxq),
	4320	+ si->dst_reg, si->src_reg,
	4321	+ offsetof(struct xdp_buff, rxq));
	4322	+ *insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->dst_reg,
	4323	+ bpf_target_off(struct xdp_rxq_info,
	4324	+ queue_index, 4, target_size));
	4325	+ break;
4307	4326	}
4308	4327
4309	4328	return insn - insn_buf;