Merge branch 'libbpf: add netfilter link attach helper'

Florian Westphal says:

====================
v4: address comment from Daniel Xu:
  - use human-readable test names in 2/2

v3: address comments from Andrii:
  - prune verbose error message in 1/2
  - use bpf_link_create internally in 1/2
  - use subtests in patch 2/2

When initial netfilter bpf program type support got added one
suggestion was to extend libbpf with a helper to ease attachment
of nf programs to the hook locations.

Add such a helper and a demo test case that attaches a dummy
program to various combinations.

I tested that the selftest fails when changing the expected
outcome (i.e., set 'success' when it should fail and v.v.).
====================

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>

1 files changed, 15 insertions, 0 deletions

diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index 754da73c643b..10642ad69d76 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -718,6 +718,21 @@ LIBBPF_API struct bpf_link *
 bpf_program__attach_freplace(const struct bpf_program *prog,
 			     int target_fd, const char *attach_func_name);
 
+struct bpf_netfilter_opts {
+	/* size of this struct, for forward/backward compatibility */
+	size_t sz;
+
+	__u32 pf;
+	__u32 hooknum;
+	__s32 priority;
+	__u32 flags;
+};
+#define bpf_netfilter_opts__last_field flags
+
+LIBBPF_API struct bpf_link *
+bpf_program__attach_netfilter(const struct bpf_program *prog,
+			      const struct bpf_netfilter_opts *opts);
+
 struct bpf_map;
 
 LIBBPF_API struct bpf_link *bpf_map__attach_struct_ops(const struct bpf_map *map);