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, 8 insertions, 0 deletions

diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index ed86b37d8024..3b0da19715e1 100644
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -741,6 +741,14 @@ int bpf_link_create(int prog_fd, int target_fd,
 		if (!OPTS_ZEROED(opts, tracing))
 			return libbpf_err(-EINVAL);
 		break;
+	case BPF_NETFILTER:
+		attr.link_create.netfilter.pf = OPTS_GET(opts, netfilter.pf, 0);
+		attr.link_create.netfilter.hooknum = OPTS_GET(opts, netfilter.hooknum, 0);
+		attr.link_create.netfilter.priority = OPTS_GET(opts, netfilter.priority, 0);
+		attr.link_create.netfilter.flags = OPTS_GET(opts, netfilter.flags, 0);
+		if (!OPTS_ZEROED(opts, netfilter))
+			return libbpf_err(-EINVAL);
+		break;
 	default:
 		if (!OPTS_ZEROED(opts, flags))
 			return libbpf_err(-EINVAL);