Re: [PATCH bpf-next v3 3/3] libbpf: add selftests for TC-BPF API

From: Yonghong Song <yhs@fb.com>
To: Kumar Kartikeya Dwivedi <memxor@gmail.com>, <bpf@vger.kernel.org>
Cc: "Toke Høiland-Jørgensen" <toke@redhat.com>,
	"Alexei Starovoitov" <ast@kernel.org>,
	"Daniel Borkmann" <daniel@iogearbox.net>,
	"Andrii Nakryiko" <andrii@kernel.org>,
	"Martin KaFai Lau" <kafai@fb.com>,
	"Song Liu" <songliubraving@fb.com>,
	"John Fastabend" <john.fastabend@gmail.com>,
	"KP Singh" <kpsingh@kernel.org>,
	"David S. Miller" <davem@davemloft.net>,
	"Jakub Kicinski" <kuba@kernel.org>,
	"Jesper Dangaard Brouer" <brouer@redhat.com>,
	netdev@vger.kernel.org
Subject: Re: [PATCH bpf-next v3 3/3] libbpf: add selftests for TC-BPF API
Date: Wed, 21 Apr 2021 00:01:39 -0700	[thread overview]
Message-ID: <2656c9ec-3d33-4646-8653-5b8069ec38bb@fb.com> (raw)
In-Reply-To: <20210420193740.124285-4-memxor@gmail.com>

On 4/20/21 12:37 PM, Kumar Kartikeya Dwivedi wrote:
> This adds some basic tests for the low level bpf_tc_* API.
> 
> Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
> Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
> ---
>   .../selftests/bpf/prog_tests/test_tc_bpf.c    | 169 ++++++++++++++++++
>   .../selftests/bpf/progs/test_tc_bpf_kern.c    |  12 ++
>   2 files changed, 181 insertions(+)
>   create mode 100644 tools/testing/selftests/bpf/prog_tests/test_tc_bpf.c
>   create mode 100644 tools/testing/selftests/bpf/progs/test_tc_bpf_kern.c
> 
> diff --git a/tools/testing/selftests/bpf/prog_tests/test_tc_bpf.c b/tools/testing/selftests/bpf/prog_tests/test_tc_bpf.c
> new file mode 100644
> index 000000000000..563a3944553c
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/prog_tests/test_tc_bpf.c
> @@ -0,0 +1,169 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +#include <linux/bpf.h>
> +#include <linux/err.h>
> +#include <linux/limits.h>
> +#include <bpf/libbpf.h>
> +#include <errno.h>
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <test_progs.h>
> +#include <linux/if_ether.h>
> +
> +#define LO_IFINDEX 1
> +
[...]
> +
> +void test_test_tc_bpf(void)
> +{
> +	const char *file = "./test_tc_bpf_kern.o";
> +	struct bpf_program *clsp;
> +	struct bpf_object *obj;
> +	int cls_fd, ret;
> +
> +	obj = bpf_object__open(file);
> +	if (!ASSERT_OK_PTR(obj, "bpf_object__open"))
> +		return;
> +
> +	clsp = bpf_object__find_program_by_title(obj, "classifier");
> +	if (!ASSERT_OK_PTR(clsp, "bpf_object__find_program_by_title"))
> +		goto end;

Please use bpf_object__find_program_by_name() API.

> +
> +	ret = bpf_object__load(obj);
> +	if (!ASSERT_EQ(ret, 0, "bpf_object__load"))
> +		goto end;
> +
> +	cls_fd = bpf_program__fd(clsp);
> +
> +	system("tc qdisc del dev lo clsact");
> +
> +	ret = test_tc_internal(cls_fd, BPF_TC_CLSACT_INGRESS);
> +	if (!ASSERT_EQ(ret, 0, "test_tc_internal INGRESS"))
> +		goto end;
> +
> +	if (!ASSERT_EQ(system("tc qdisc del dev lo clsact"), 0,
> +		       "clsact qdisc delete failed"))
> +		goto end;
> +
> +	ret = test_tc_info(cls_fd);
> +	if (!ASSERT_EQ(ret, 0, "test_tc_info"))
> +		goto end;
> +
> +	if (!ASSERT_EQ(system("tc qdisc del dev lo clsact"), 0,
> +		       "clsact qdisc delete failed"))
> +		goto end;
> +
> +	ret = test_tc_internal(cls_fd, BPF_TC_CLSACT_EGRESS);
> +	if (!ASSERT_EQ(ret, 0, "test_tc_internal EGRESS"))
> +		goto end;
> +
> +	ASSERT_EQ(system("tc qdisc del dev lo clsact"), 0,
> +		  "clsact qdisc delete failed");
> +
> +end:
> +	bpf_object__close(obj);
> +}
> diff --git a/tools/testing/selftests/bpf/progs/test_tc_bpf_kern.c b/tools/testing/selftests/bpf/progs/test_tc_bpf_kern.c
> new file mode 100644
> index 000000000000..18a3a7ed924a
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/progs/test_tc_bpf_kern.c
> @@ -0,0 +1,12 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +#include <linux/bpf.h>
> +#include <bpf/bpf_helpers.h>
> +
> +/* Dummy prog to test TC-BPF API */
> +
> +SEC("classifier")
> +int cls(struct __sk_buff *skb)
> +{
> +	return 0;
> +}
> 