selftests: add dummy xdp test helper

This trivial XDP program does nothing, but will be used by the
next patch to test the GRO path in a net namespace, leveraging
the veth XDP implementation.

It's added here, despite its 'net' usage, to avoid the duplication
of the llc-related makefile boilerplate.

rfc v3 -> v1:
 - move the helper implementation into the bpf directory, don't
   touch udpgso_bench_rx

rfc v2 -> rfc v3:
 - move 'x' option handling here

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 13 insertions, 0 deletions

diff --git a/tools/testing/selftests/bpf/xdp_dummy.c b/tools/testing/selftests/bpf/xdp_dummy.c
new file mode 100644
index 000000000000..43b0ef1001ed
--- /dev/null
+++ b/tools/testing/selftests/bpf/xdp_dummy.c
@@ -0,0 +1,13 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#define KBUILD_MODNAME "xdp_dummy"
+#include <linux/bpf.h>
+#include "bpf_helpers.h"
+
+SEC("xdp_dummy")
+int xdp_dummy_prog(struct xdp_md *ctx)
+{
+	return XDP_PASS;
+}
+
+char _license[] SEC("license") = "GPL";