Re: [PATCH bpf-next] selftests/bpf: move netcnt test under test_progs

[Yonghong Song <yhs@fb.com>]

On 7/28/21 8:14 AM, Stanislav Fomichev wrote:
> Rewrite to skel and ASSERT macros as well while we are at it.
> 
> Signed-off-by: Stanislav Fomichev <sdf@google.com>

Thanks for converting test_netcnt to test_progs.
The patch looks good to me except a couple of minor issues.

Acked-by: Yonghong Song <yhs@fb.com>

> ---
>   tools/testing/selftests/bpf/Makefile          |   3 +-
>   .../testing/selftests/bpf/prog_tests/netcnt.c |  93 +++++++++++
>   tools/testing/selftests/bpf/test_netcnt.c     | 148 ------------------
>   3 files changed, 94 insertions(+), 150 deletions(-)
>   create mode 100644 tools/testing/selftests/bpf/prog_tests/netcnt.c
>   delete mode 100644 tools/testing/selftests/bpf/test_netcnt.c
> 
> diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
> index f405b20c1e6c..2a58b7b5aea4 100644
> --- a/tools/testing/selftests/bpf/Makefile
> +++ b/tools/testing/selftests/bpf/Makefile
> @@ -38,7 +38,7 @@ TEST_GEN_PROGS = test_verifier test_tag test_maps test_lru_map test_lpm_map test
>   	test_verifier_log test_dev_cgroup \
>   	test_sock test_sockmap get_cgroup_id_user \
>   	test_cgroup_storage \
> -	test_netcnt test_tcpnotify_user test_sysctl \
> +	test_tcpnotify_user test_sysctl \
>   	test_progs-no_alu32
>   
>   # Also test bpf-gcc, if present
> @@ -197,7 +197,6 @@ $(OUTPUT)/test_sockmap: cgroup_helpers.c
>   $(OUTPUT)/test_tcpnotify_user: cgroup_helpers.c trace_helpers.c
>   $(OUTPUT)/get_cgroup_id_user: cgroup_helpers.c
>   $(OUTPUT)/test_cgroup_storage: cgroup_helpers.c
> -$(OUTPUT)/test_netcnt: cgroup_helpers.c
>   $(OUTPUT)/test_sock_fields: cgroup_helpers.c
>   $(OUTPUT)/test_sysctl: cgroup_helpers.c
>   
> diff --git a/tools/testing/selftests/bpf/prog_tests/netcnt.c b/tools/testing/selftests/bpf/prog_tests/netcnt.c
> new file mode 100644
> index 000000000000..063a40d228b6
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/prog_tests/netcnt.c
> @@ -0,0 +1,93 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +#include <sys/sysinfo.h>
> +#include <test_progs.h>
> +#include "netcnt_prog.skel.h"
> +#include "netcnt_common.h"
> +
> +#define CG_NAME "/netcnt"
> +
> +void test_netcnt(void)
> +{
> +	union percpu_net_cnt *percpu_netcnt = NULL;
> +	struct bpf_cgroup_storage_key key;
> +	int map_fd, percpu_map_fd;
> +	struct netcnt_prog *skel;
> +	unsigned long packets;
> +	union net_cnt netcnt;
> +	unsigned long bytes;
> +	int cpu, nproc;
> +	int cg_fd = -1;
> +
> +	skel = netcnt_prog__open_and_load();
> +	if (!ASSERT_OK_PTR(skel, "netcnt_prog__open_and_load"))
> +		return;
> +
> +	nproc = get_nprocs_conf();
> +	percpu_netcnt = malloc(sizeof(*percpu_netcnt) * nproc);
> +	if (!ASSERT_OK_PTR(percpu_netcnt, "malloc(percpu_netcnt)"))
> +		goto err;
> +
> +	cg_fd = test__join_cgroup(CG_NAME);
> +	if (!ASSERT_GE(cg_fd, 0, "test__join_cgroup"))
> +		goto err;
> +
> +	skel->links.bpf_nextcnt =
> +		bpf_program__attach_cgroup(skel->progs.bpf_nextcnt, cg_fd);
> +	if (!ASSERT_OK_PTR(skel->links.bpf_nextcnt,
> +			   "attach_cgroup(bpf_nextcnt)"))
> +		goto err;
> +
> +	if (system("which ping6 &>/dev/null") == 0)
> +		assert(!system("ping6 ::1 -c 10000 -f -q > /dev/null"));
> +	else
> +		assert(!system("ping -6 ::1 -c 10000 -f -q > /dev/null"));
> +
> +	map_fd = bpf_map__fd(skel->maps.netcnt);
> +	if (!ASSERT_GE(map_fd, 0, "bpf_map__fd(netcnt)"))
> +		goto err;

For skeleton, map_fd is always valid and you do not need to check it.

> +
> +	percpu_map_fd = bpf_map__fd(skel->maps.percpu_netcnt);
> +	if (!ASSERT_GE(percpu_map_fd, 0, "bpf_map__fd(percpu_netcnt)"))
> +		goto err;

The same for percpu_map_fd, it is always valid and no need to check it.

> +
> +	if (!ASSERT_OK(bpf_map_get_next_key(map_fd, NULL, &key),
> +		       "bpf_map_get_next_key"))
> +		goto err;
> +
> +	if (!ASSERT_OK(bpf_map_lookup_elem(map_fd, &key, &netcnt),
> +		       "bpf_map_lookup_elem(netcnt)"))
> +		goto err;
> +
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