libbpf: Add link-based API for netkit

This adds bpf_program__attach_netkit() API to libbpf. Overall it is very
similar to tcx. The API looks as following:

  LIBBPF_API struct bpf_link *
  bpf_program__attach_netkit(const struct bpf_program *prog, int ifindex,
                             const struct bpf_netkit_opts *opts);

The struct bpf_netkit_opts is done in similar way as struct bpf_tcx_opts
for supporting bpf_mprog control parameters. The attach location for the
primary and peer device is derived from the program section "netkit/primary"
and "netkit/peer", respectively.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20231024214904.29825-4-daniel@iogearbox.net
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>

1 files changed, 15 insertions, 0 deletions

diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index 475378438545..6cd9c501624f 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -800,6 +800,21 @@ LIBBPF_API struct bpf_link *
 bpf_program__attach_tcx(const struct bpf_program *prog, int ifindex,
 			const struct bpf_tcx_opts *opts);
 
+struct bpf_netkit_opts {
+	/* size of this struct, for forward/backward compatibility */
+	size_t sz;
+	__u32 flags;
+	__u32 relative_fd;
+	__u32 relative_id;
+	__u64 expected_revision;
+	size_t :0;
+};
+#define bpf_netkit_opts__last_field expected_revision
+
+LIBBPF_API struct bpf_link *
+bpf_program__attach_netkit(const struct bpf_program *prog, int ifindex,
+			   const struct bpf_netkit_opts *opts);
+
 struct bpf_map;
 
 LIBBPF_API struct bpf_link *bpf_map__attach_struct_ops(const struct bpf_map *map);