selftests/bpf: Add mprog API tests for BPF tcx opts

Add a big batch of test coverage to assert all aspects of the tcx opts
attach, detach and query API:

  # ./vmtest.sh -- ./test_progs -t tc_opts
  [...]
  #238     tc_opts_after:OK
  #239     tc_opts_append:OK
  #240     tc_opts_basic:OK
  #241     tc_opts_before:OK
  #242     tc_opts_chain_classic:OK
  #243     tc_opts_demixed:OK
  #244     tc_opts_detach:OK
  #245     tc_opts_detach_after:OK
  #246     tc_opts_detach_before:OK
  #247     tc_opts_dev_cleanup:OK
  #248     tc_opts_invalid:OK
  #249     tc_opts_mixed:OK
  #250     tc_opts_prepend:OK
  #251     tc_opts_replace:OK
  #252     tc_opts_revision:OK
  Summary: 15/0 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/20230719140858.13224-8-daniel@iogearbox.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 40 insertions, 0 deletions

diff --git a/tools/testing/selftests/bpf/progs/test_tc_link.c b/tools/testing/selftests/bpf/progs/test_tc_link.c
new file mode 100644
index 000000000000..ed1fd0e9cee9
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_tc_link.c
@@ -0,0 +1,40 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2023 Isovalent */
+#include <stdbool.h>
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+
+char LICENSE[] SEC("license") = "GPL";
+
+bool seen_tc1;
+bool seen_tc2;
+bool seen_tc3;
+bool seen_tc4;
+
+SEC("tc/ingress")
+int tc1(struct __sk_buff *skb)
+{
+	seen_tc1 = true;
+	return TCX_NEXT;
+}
+
+SEC("tc/egress")
+int tc2(struct __sk_buff *skb)
+{
+	seen_tc2 = true;
+	return TCX_NEXT;
+}
+
+SEC("tc/egress")
+int tc3(struct __sk_buff *skb)
+{
+	seen_tc3 = true;
+	return TCX_NEXT;
+}
+
+SEC("tc/egress")
+int tc4(struct __sk_buff *skb)
+{
+	seen_tc4 = true;
+	return TCX_NEXT;
+}