Re: [PATCH v2 2/2] selftests/bpf: integrate test_xdp_veth into test_progs

Simon Horman
2024-07-15T12:27:44Z

On Mon, Jul 15, 2024 at 11:53:45AM +0200, Alexis Lothoré (eBPF Foundation) wrote:
> test_xdp_veth.sh tests that XDP return codes work as expected, by bringing
> up multiple veth pairs isolated in different namespaces, attaching specific
> xdp programs to each interface, and ensuring that the whole chain allows to
> ping one end interface from the first one. The test runs well but is
> currently not integrated in test_progs, which prevents it from being run
> automatically in the CI infrastructure.
>
> Rewrite it as a C test relying on libbpf to allow running it in the CI
> infrastructure. The new code brings up the same network infrastructure and
> reuses the same eBPF programs as test_xdp_veth.sh, for which skeletons are
> already generated by the bpf tests makefile.
>
> Signed-off-by: Alexis Lothoré (eBPF Foundation) <alexis.lothore@bootlin.com>
> ---
> The new code has been tested in an aarch64 qemu instance:
> Summary: 1/0 PASSED, 0 SKIPPED, 0 FAILED
>
> I have also checked that some minor alterations in the network
> configuration (altering the redirect map, or not loading one of the xdp
> programs) make the test fail.
>
> On my testing setup, the test takes a bit more than 3 seconds to run on
> average.
>
> Changes in v2:
> - fix many formatting issues raised by checkpatch
> - use static namespaces instead of random ones
> - use SYS_NOFAIL instead of snprintf() + system ()
> - squashed the new test addition patch and the old test removal patch
> ---
> tools/testing/selftests/bpf/Makefile | 1 -
> .../selftests/bpf/prog_tests/test_xdp_veth.c | 211 +++++++++++++++++++++
> tools/testing/selftests/bpf/test_xdp_veth.sh | 121 ------------
> 3 files changed, 211 insertions(+), 122 deletions(-)
>
> diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
> index a7932bead77d..2864a0dc04d5 100644
> --- a/tools/testing/selftests/bpf/Makefile
> +++ b/tools/testing/selftests/bpf/Makefile
> @@ -117,7 +117,6 @@ TEST_PROGS := test_kmod.sh \
> test_xdp_redirect.sh \
> test_xdp_redirect_multi.sh \
> test_xdp_meta.sh \
> - test_xdp_veth.sh \
> test_tunnel.sh \
> test_lwt_seg6local.sh \
> test_lirc_mode2.sh \
> diff --git a/tools/testing/selftests/bpf/prog_tests/test_xdp_veth.c b/tools/testing/selftests/bpf/prog_tests/test_xdp_veth.c
> new file mode 100644
> index 000000000000..3ffeb411c131
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/prog_tests/test_xdp_veth.c
> @@ -0,0 +1,211 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/**
> + * Create 3 namespaces with 3 veth peers, and
> + * forward packets in-between using native XDP
> + *
> + * XDP_TX
> + * NS1(veth11) NS2(veth22) NS3(veth33)
> + * | | |
> + * | | |
> + * (veth1, (veth2, (veth3,
> + * id:111) id:122) id:133)
> + * ^ | ^ | ^ |
> + * | | XDP_REDIRECT | | XDP_REDIRECT | |
> + * | ------------------ ------------------ |
> + * -----------------------------------------
> + * XDP_REDIRECT
> + */

Hi Alexis,

A minor nit from my side.

The comment above starts with '/**' but otherwise it is not a Kernel doc.
It's probably best if it's a networking-style multi-line comment instead.

/* Create 3 namespaces with 3 veth peers, and
* ...
*/

...