Re: [PATCH RESEND bpf-next 13/15] selftests/bpf: Allow VLAN packets in xdp_hw_metadata

From: Stanislav Fomichev <sdf@google.com>
To: Larysa Zaremba <larysa.zaremba@intel.com>
Cc: bpf@vger.kernel.org, Alexei Starovoitov <ast@kernel.org>,
	 Daniel Borkmann <daniel@iogearbox.net>,
	Andrii Nakryiko <andrii@kernel.org>,
	 Jakub Kicinski <kuba@kernel.org>,
	Martin KaFai Lau <martin.lau@linux.dev>,
	Song Liu <song@kernel.org>,  Yonghong Song <yhs@fb.com>,
	John Fastabend <john.fastabend@gmail.com>,
	KP Singh <kpsingh@kernel.org>,  Jiri Olsa <jolsa@kernel.org>,
	Jesse Brandeburg <jesse.brandeburg@intel.com>,
	 Tony Nguyen <anthony.l.nguyen@intel.com>,
	Anatoly Burakov <anatoly.burakov@intel.com>,
	 Jesper Dangaard Brouer <brouer@redhat.com>,
	Alexander Lobakin <alexandr.lobakin@intel.com>,
	 Magnus Karlsson <magnus.karlsson@gmail.com>,
	Maryam Tahhan <mtahhan@redhat.com>,
	 xdp-hints@xdp-project.net, netdev@vger.kernel.org,
	 intel-wired-lan@lists.osuosl.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH RESEND bpf-next 13/15] selftests/bpf: Allow VLAN packets in xdp_hw_metadata
Date: Fri, 12 May 2023 11:33:34 -0700	[thread overview]
Message-ID: <ZF6GfoZVgKX78bpq@google.com> (raw)
In-Reply-To: <20230512152607.992209-14-larysa.zaremba@intel.com>

On 05/12, Larysa Zaremba wrote:
> Make VLAN c-tag and s-tag XDP hint testing more convenient
> by not skipping VLAN-ed packets.
> 
> Allow both 802.1ad and 802.1Q headers.

Can we also extend non-hw test? That should require adding metadata
handlers to veth to extract relevant parts from skb + update ip link
commands to add vlan id. Should be relatively easy to do?

> 
> Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com>
> ---
>  tools/testing/selftests/bpf/progs/xdp_hw_metadata.c | 9 ++++++++-
>  tools/testing/selftests/bpf/xdp_metadata.h          | 8 ++++++++
>  2 files changed, 16 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/testing/selftests/bpf/progs/xdp_hw_metadata.c b/tools/testing/selftests/bpf/progs/xdp_hw_metadata.c
> index b2dfd7066c6e..f95f82a8b449 100644
> --- a/tools/testing/selftests/bpf/progs/xdp_hw_metadata.c
> +++ b/tools/testing/selftests/bpf/progs/xdp_hw_metadata.c
> @@ -26,15 +26,22 @@ int rx(struct xdp_md *ctx)
>  {
>  	void *data, *data_meta, *data_end;
>  	struct ipv6hdr *ip6h = NULL;
> -	struct ethhdr *eth = NULL;
>  	struct udphdr *udp = NULL;
>  	struct iphdr *iph = NULL;
>  	struct xdp_meta *meta;
> +	struct ethhdr *eth;
>  	int err;
>  
>  	data = (void *)(long)ctx->data;
>  	data_end = (void *)(long)ctx->data_end;
>  	eth = data;
> +
> +	if (eth + 1 < data_end && eth->h_proto == bpf_htons(ETH_P_8021AD))
> +		eth = (void *)eth + sizeof(struct vlan_hdr);
> +
> +	if (eth + 1 < data_end && eth->h_proto == bpf_htons(ETH_P_8021Q))
> +		eth = (void *)eth + sizeof(struct vlan_hdr);
> +
>  	if (eth + 1 < data_end) {
>  		if (eth->h_proto == bpf_htons(ETH_P_IP)) {
>  			iph = (void *)(eth + 1);
> diff --git a/tools/testing/selftests/bpf/xdp_metadata.h b/tools/testing/selftests/bpf/xdp_metadata.h
> index 938a729bd307..6664893c2c77 100644
> --- a/tools/testing/selftests/bpf/xdp_metadata.h
> +++ b/tools/testing/selftests/bpf/xdp_metadata.h
> @@ -9,6 +9,14 @@
>  #define ETH_P_IPV6 0x86DD
>  #endif
>  
> +#ifndef ETH_P_8021Q
> +#define ETH_P_8021Q 0x8100
> +#endif
> +
> +#ifndef ETH_P_8021AD
> +#define ETH_P_8021AD 0x88A8
> +#endif
> +
>  struct xdp_meta {
>  	__u64 rx_timestamp;
>  	__u64 xdp_timestamp;
> -- 
> 2.35.3
> 