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From:   Lorenz Bauer <lmb@cloudflare.com>
Date:   Thu, 20 Aug 2020 17:12:18 +0100
Message-ID: <CACAyw98oAK2Ds1DShkNHq6AYKNF0sL_LOAji3rriuxRa35brAA@mail.gmail.com>
Subject: Re: [PATCH bpf-next 6/6] selftests: bpf: test sockmap update from BPF
To:     Yonghong Song <yhs@fb.com>
Cc:     Jakub Sitnicki <jakub@cloudflare.com>,
        John Fastabend <john.fastabend@gmail.com>,
        Shuah Khan <shuah@kernel.org>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        kernel-team <kernel-team@cloudflare.com>,
        LKML <linux-kernel@vger.kernel.org>,
        linux-kselftest@vger.kernel.org,
        Networking <netdev@vger.kernel.org>, bpf <bpf@vger.kernel.org>
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On Thu, 20 Aug 2020 at 15:49, Yonghong Song <yhs@fb.com> wrote:
>
>
>
> On 8/20/20 4:58 AM, Lorenz Bauer wrote:
> > On Wed, 19 Aug 2020 at 21:46, Yonghong Song <yhs@fb.com> wrote:
> >>
> >>
> >>
> >> On 8/19/20 2:24 AM, Lorenz Bauer wrote:
> >>> Add a test which copies a socket from a sockmap into another sockmap
> >>> or sockhash. This excercises bpf_map_update_elem support from BPF
> >>> context. Compare the socket cookies from source and destination to
> >>> ensure that the copy succeeded.
> >>>
> >>> Signed-off-by: Lorenz Bauer <lmb@cloudflare.com>
> >>> ---
> >>>    .../selftests/bpf/prog_tests/sockmap_basic.c  | 76 +++++++++++++++++++
> >>>    .../selftests/bpf/progs/test_sockmap_copy.c   | 48 ++++++++++++
> >>>    2 files changed, 124 insertions(+)
> >>>    create mode 100644 tools/testing/selftests/bpf/progs/test_sockmap_copy.c
> >>>
> >>> diff --git a/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c b/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c
> >>> index 96e7b7f84c65..d30cabc00e9e 100644
> >>> --- a/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c
> >>> +++ b/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c
> >>> @@ -4,6 +4,7 @@
> >>>
> >>>    #include "test_progs.h"
> >>>    #include "test_skmsg_load_helpers.skel.h"
> >>> +#include "test_sockmap_copy.skel.h"
> >>>
> >>>    #define TCP_REPAIR          19      /* TCP sock is under repair right now */
> >>>
> >>> @@ -101,6 +102,77 @@ static void test_skmsg_helpers(enum bpf_map_type map_type)
> >>>        test_skmsg_load_helpers__destroy(skel);
> >>>    }
> >>>
> >>> +static void test_sockmap_copy(enum bpf_map_type map_type)
> >>> +{
> >>> +     struct bpf_prog_test_run_attr attr;
> >>> +     struct test_sockmap_copy *skel;
> >>> +     __u64 src_cookie, dst_cookie;
> >>> +     int err, prog, s, src, dst;
> >>> +     const __u32 zero = 0;
> >>> +     char dummy[14] = {0};
> >>> +
> >>> +     s = connected_socket_v4();
> >>
> >> Maybe change variable name to "sk" for better clarity?
> >
> > Yup!
> >
> >>
> >>> +     if (CHECK_FAIL(s == -1))
> >>> +             return;
> >>> +
> >>> +     skel = test_sockmap_copy__open_and_load();
> >>> +     if (CHECK_FAIL(!skel)) {
> >>> +             close(s);
> >>> +             perror("test_sockmap_copy__open_and_load");
> >>> +             return;
> >>> +     }
> >>
> >> Could you use CHECK instead of CHECK_FAIL?
> >> With CHECK, you can print additional information without perror.
> >
> > I avoid CHECK because it requires `duration`, which doesn't make sense
> > for most things that I call CHECK_FAIL on here. So either it outputs 0
> > nsec (which is bogus) or it outputs the value from the last
> > bpf_prog_test_run call (which is also bogus). How do other tests
> > handle this? Just ignore it?
>
> Just ignore it. You can define a static variable duration in the
> beginning of file and then use CHECK in the rest of file.

Ok, will do in v3!

>
> >
> >>
> >>
> >>> +
> >>> +     prog = bpf_program__fd(skel->progs.copy_sock_map);
> >>> +     src = bpf_map__fd(skel->maps.src);
> >>> +     if (map_type == BPF_MAP_TYPE_SOCKMAP)
> >>> +             dst = bpf_map__fd(skel->maps.dst_sock_map);
> >>> +     else
> >>> +             dst = bpf_map__fd(skel->maps.dst_sock_hash);
> >>> +
> [...]


-- 
Lorenz Bauer  |  Systems Engineer
6th Floor, County Hall/The Riverside Building, SE1 7PB, UK

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