[xdp-hints] Re: [PATCH bpf-next v2 16/20] selftests/bpf: Add flags and new hints to xdp_hw_metadata

[Jesper Dangaard Brouer <jbrouer@redhat.com>]

On 03/07/2023 20.12, Larysa Zaremba wrote:
> diff --git a/tools/testing/selftests/bpf/xdp_hw_metadata.c b/tools/testing/selftests/bpf/xdp_hw_metadata.c
> index 613321eb84c1..d234cbcc9103 100644
> --- a/tools/testing/selftests/bpf/xdp_hw_metadata.c
> +++ b/tools/testing/selftests/bpf/xdp_hw_metadata.c
> @@ -19,6 +19,9 @@
>   #include "xsk.h"
>   
>   #include <error.h>
> +#include <linux/kernel.h>
> +#include <linux/bits.h>
> +#include <linux/bitfield.h>
>   #include <linux/errqueue.h>
>   #include <linux/if_link.h>
>   #include <linux/net_tstamp.h>
> @@ -150,21 +153,34 @@ static __u64 gettime(clockid_t clock_id)
>   	return (__u64) t.tv_sec * NANOSEC_PER_SEC + t.tv_nsec;
>   }
>   
> +#define VLAN_PRIO_MASK		GENMASK(15, 13) /* Priority Code Point */
> +#define VLAN_CFI_MASK		GENMASK(12, 12) /* Canonical Format / Drop Eligible Indicator */
> +#define VLAN_VID_MASK		GENMASK(11, 0)	/* VLAN Identifier */
> +static void print_vlan_tag(__u16 tag)
> +{
> +	__u16 vlan_id = FIELD_GET(VLAN_VID_MASK, tag);
> +	__u8 pcp = FIELD_GET(VLAN_PRIO_MASK, tag);
> +	bool cfi = FIELD_GET(VLAN_CFI_MASK, tag);
> +
> +	printf("PCP=%u, CFI=%d, VID=0x%X\n", pcp, cfi, vlan_id);
> +}
> +

Shouldn't we use DEI instead of CFI ?

This is new code, and CFI have been deprecated (it was only relevant for
IEEE 802.5 Token Ring LAN).

--Jesper