Subject: Re: [xdp-hints] [PATCH bpf-next 06/11] xdp: Carry over xdp metadata into skb context

From: Toke Høiland-Jørgensen <[email-masked]>
Date: Wed, 16 Nov 2022 00:20:26 +0100

> diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
> index b444b1118c4f..71e3bc7ad839 100644
> --- a/include/uapi/linux/bpf.h
> +++ b/include/uapi/linux/bpf.h
> @@ -6116,6 +6116,12 @@ enum xdp_action {
>  	XDP_REDIRECT,
>  };
>  
> +/* Subset of XDP metadata exported to skb context.
> + */
> +struct xdp_skb_metadata {
> +	__u64 rx_timestamp;
> +};

Okay, so given Alexei's comment about __randomize_struct not actually
working, I think we need to come up with something else for this. Just
sticking this in a regular UAPI header seems like a bad idea; we'd just
be inviting people to use it as-is.

Do we actually need the full definition here? It's just a pointer
declaration below, so is an opaque forward-definition enough? Then we
could have the full definition in an internal header, moving the full
definition back to being in vmlinux.h only?

-Toke