netdev - Re: [PATCH bpf-next V1 7/7] net: xdp: update documentation for xdp-rx-metadata.rst

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <75b370cb-222c-411a-a961-d99a6c9dabe0@iogearbox.net>
Date: Fri, 13 Jun 2025 13:18:25 +0200
From: Daniel Borkmann <daniel@...earbox.net>
To: Toke Høiland-Jørgensen <toke@...hat.com>,
 Stanislav Fomichev <stfomichev@...il.com>,
 Jesper Dangaard Brouer <hawk@...nel.org>
Cc: bpf@...r.kernel.org, netdev@...r.kernel.org,
 Jakub Kicinski <kuba@...nel.org>, lorenzo@...nel.org,
 Alexei Starovoitov <ast@...nel.org>, Daniel Borkmann
 <borkmann@...earbox.net>, Eric Dumazet <eric.dumazet@...il.com>,
 "David S. Miller" <davem@...emloft.net>, Paolo Abeni <pabeni@...hat.com>,
 sdf@...ichev.me, kernel-team@...udflare.com, arthur@...hurfabre.com,
 jakub@...udflare.com, Magnus Karlsson <magnus.karlsson@...el.com>,
 Maciej Fijalkowski <maciej.fijalkowski@...el.com>
Subject: Re: [PATCH bpf-next V1 7/7] net: xdp: update documentation for
 xdp-rx-metadata.rst

On 6/10/25 10:12 PM, Toke Høiland-Jørgensen wrote:
> Daniel Borkmann <daniel@...earbox.net> writes:
[...]
>> Also, have you thought about taking the opportunity to generalize the existing
>> struct xsk_tx_metadata? It would be nice to actually use the same/similar struct
>> for RX and TX, similarly as done in struct virtio_net_hdr. Such that we have
>> XDP_{RX,TX}_METADATA and XDP_{RX,TX}MD_FLAGS_* to describe what meta data we
>> have and from a developer PoV this will be a nicely consistent API in XDP. Then
>> you could store at the right location in the meta data region just with
>> bpf_xdp_metadata_* kfuncs (and/or plain BPF code) and finally set XDP_RX_METADATA
>> indicator bit.
> 
> Wouldn't this make the whole thing (effectively) UAPI?

I'm not sure I follow, we already have this in place for the meta data region
in AF_XDP, this would extend the scope to RX as well, so there would be a similar
'look and feel' in that sense it is already a developer API which is used.

Cheers,
Daniel