Commit c1931c97 authored by Andrii Nakryiko's avatar Andrii Nakryiko Committed by Alexei Starovoitov
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bpf: Implement BPF XDP link-specific introspection APIs 



Implement XDP link-specific show_fdinfo and link_info to emit ifindex.

Signed-off-by: default avatarAndrii Nakryiko <andriin@fb.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200722064603.3350758-7-andriin@fb.com
parent 026a4c28

include/uapi/linux/bpf.h

+3 −0
Original line number Diff line number Diff line
@@ -4069,6 +4069,9 @@ struct bpf_link_info { 
			__u32 netns_ino;

			__u32 attach_type;

		} netns;

		struct {

			__u32 ifindex;

		} xdp;

	};

} __attribute__((aligned(8)));

net/core/dev.c

+31 −0
Original line number Diff line number Diff line
@@ -8996,6 +8996,35 @@ static void bpf_xdp_link_dealloc(struct bpf_link *link) 
	kfree(xdp_link);

}



static void bpf_xdp_link_show_fdinfo(const struct bpf_link *link,

				     struct seq_file *seq)

{

	struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);

	u32 ifindex = 0;



	rtnl_lock();

	if (xdp_link->dev)

		ifindex = xdp_link->dev->ifindex;

	rtnl_unlock();



	seq_printf(seq, "ifindex:\t%u\n", ifindex);

}



static int bpf_xdp_link_fill_link_info(const struct bpf_link *link,

				       struct bpf_link_info *info)

{

	struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);

	u32 ifindex = 0;



	rtnl_lock();

	if (xdp_link->dev)

		ifindex = xdp_link->dev->ifindex;

	rtnl_unlock();



	info->xdp.ifindex = ifindex;

	return 0;

}



static int bpf_xdp_link_update(struct bpf_link *link, struct bpf_prog *new_prog,

			       struct bpf_prog *old_prog)

{
@@ -9041,6 +9070,8 @@ out_unlock: 
static const struct bpf_link_ops bpf_xdp_link_lops = {

	.release = bpf_xdp_link_release,

	.dealloc = bpf_xdp_link_dealloc,

	.show_fdinfo = bpf_xdp_link_show_fdinfo,

	.fill_link_info = bpf_xdp_link_fill_link_info,

	.update_prog = bpf_xdp_link_update,

};

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