selftests/bpf: Avoid pinning prog when attaching to tc ingress in btf_skc_cls_ingress

This patch removes the need to pin prog when attaching to tc ingress
in the btf_skc_cls_ingress test. Instead, directly use the
bpf_tc_hook_create() and bpf_tc_attach(). The qdisc clsact
will go away together with the netns, so no need to
bpf_tc_hook_destroy().

Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/bpf/20221129070900.3142427-8-martin.lau@linux.dev

selftests/bpf: Deduplicate write_sysctl() to test_progs.c

This helper is needed in multiple tests. Instead of copying it over
and over, better to deduplicate this helper to test_progs.c.

test_progs.c is chosen over testing_helpers.c because of this helper's
use of CHECK / ASSERT_*, and the CHECK was modified to use ASSERT_*
so it does not rely on a duration variable.

Suggested-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: YiFei Zhu <zhuyifei@google.com>
Link: https://lore.kernel.org/r/9b4fc9a27bd52f771b657b4c4090fc8d61f3a6b5.1662682323.git.zhuyifei@google.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>

bpf, selftests: Fix racing issue in btf_skc_cls_ingress test

The libbpf CI reported occasional failure in btf_skc_cls_ingress:

test_syncookie:FAIL:Unexpected syncookie states gen_cookie:80326634 recv_cookie:0
bpf prog error at line 97

"error at line 97" means the bpf prog cannot find the listening socket
when the final ack is received. It then skipped processing
the syncookie in the final ack which then led to "recv_cookie:0".

The problem is the userspace program did not do accept() and went
ahead to close(listen_fd) before the kernel (and the bpf prog) had
a chance to process the final ack.

The fix is to add accept() call so that the userspace will wait for
the kernel to finish processing the final ack first before close()-ing
everything.

Fixes: 9a856cae2217 ("bpf: selftest: Add test_btf_skc_cls_ingress")
Reported-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20211216191630.466151-1-kafai@fb.com

bpf: selftest: Use static globals in tcp_hdr_options and btf_skc_cls_ingress

Some globals in the tcp_hdr_options test and btf_skc_cls_ingress test
are not using static scope. This patch fixes it.

Targeting bpf-next branch as an improvement since it currently does not
break the build.

Fixes: ad2f8eb0095e ("bpf: selftests: Tcp header options")
Fixes: 9a856cae2217 ("bpf: selftest: Add test_btf_skc_cls_ingress")
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20201106225402.4135741-1-kafai@fb.com

selftests: Make sure all 'skel' variables are declared static

If programs in prog_tests using skeletons declare the 'skel' variable as
global but not static, that will lead to linker errors on the final link of
the prog_tests binary due to duplicate symbols. Fix a few instances of this.

Fixes: b18c1f0aa477 ("bpf: selftest: Adapt sock_fields test to use skel and global variables")
Fixes: 9a856cae2217 ("bpf: selftest: Add test_btf_skc_cls_ingress")
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200929123026.46751-1-toke@redhat.com

bpf: selftest: Add test_btf_skc_cls_ingress

This patch attaches a classifier prog to the ingress filter.
It exercises the following helpers with different socket pointer
types in different logical branches:
1. bpf_sk_release()
2. bpf_sk_assign()
3. bpf_skc_to_tcp_request_sock(), bpf_skc_to_tcp_sock()
4. bpf_tcp_gen_syncookie, bpf_tcp_check_syncookie

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200925000458.3859627-1-kafai@fb.com