Re: [PATCH v3 bpf 2/2] selftests/bpf: test lwt redirect error handling

[Jakub Sitnicki <jakub@cloudflare.com>]

On Mon, Jul 24, 2023 at 09:14 PM -07, Yan Zhai wrote:
> Tests BPF redirect at the lwt xmit hook to ensure error handling are
> safe, i.e. won't panic the kernel.
>
> Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
> Signed-off-by: Yan Zhai <yan@cloudflare.com>
> ---
>  tools/testing/selftests/bpf/Makefile          |   1 +
>  .../selftests/bpf/progs/test_lwt_redirect.c   |  67 +++++++
>  .../selftests/bpf/test_lwt_redirect.sh        | 165 ++++++++++++++++++
>  3 files changed, 233 insertions(+)
>  create mode 100644 tools/testing/selftests/bpf/progs/test_lwt_redirect.c
>  create mode 100755 tools/testing/selftests/bpf/test_lwt_redirect.sh
>
> diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
> index 538df8fb8c42..e3a24d053793 100644
> --- a/tools/testing/selftests/bpf/Makefile
> +++ b/tools/testing/selftests/bpf/Makefile
> @@ -66,6 +66,7 @@ TEST_PROGS := test_kmod.sh \
>  	test_xdp_vlan_mode_generic.sh \
>  	test_xdp_vlan_mode_native.sh \
>  	test_lwt_ip_encap.sh \
> +	test_lwt_redirect.sh \
>  	test_tcp_check_syncookie.sh \
>  	test_tc_tunnel.sh \
>  	test_tc_edt.sh \
> diff --git a/tools/testing/selftests/bpf/progs/test_lwt_redirect.c b/tools/testing/selftests/bpf/progs/test_lwt_redirect.c
> new file mode 100644
> index 000000000000..622c6b1e7128
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/progs/test_lwt_redirect.c
> @@ -0,0 +1,67 @@
> +// SPDX-License-Identifier: GPL-2.0
> +#include <linux/bpf.h>
> +#include <bpf/bpf_helpers.h>
> +
> +#define ETH_LEN 14

Nit: We have ETH_HLEN in bpf_tracing_net.h defined.

[...]