Subject: Re: [RFC PATCH 14/17] libbpf: Add support for querying dequeue programs

From: Toke Høiland-Jørgensen <[email-masked]>
Date: Thu, 14 Jul 2022 12:13:43 +0200

Andrii Nakryiko <[email-masked]> writes:

> On Wed, Jul 13, 2022 at 4:15 AM Toke Høiland-Jørgensen <[email-masked]> wrote:
>>
>> Add support to libbpf for reading the dequeue program ID from netlink when
>> querying for installed XDP programs. No additional support is needed to
>> install dequeue programs, as they are just using a new mode flag for the
>> regular XDP program installation mechanism.
>>
>> Signed-off-by: Toke Høiland-Jørgensen <[email-masked]>
>> ---
>>  tools/lib/bpf/libbpf.h  | 1 +
>>  tools/lib/bpf/netlink.c | 8 ++++++++
>>  2 files changed, 9 insertions(+)
>>
>> diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
>> index e4d5353f757b..b15ff90279cb 100644
>> --- a/tools/lib/bpf/libbpf.h
>> +++ b/tools/lib/bpf/libbpf.h
>> @@ -906,6 +906,7 @@ struct bpf_xdp_query_opts {
>>         __u32 drv_prog_id;      /* output */
>>         __u32 hw_prog_id;       /* output */
>>         __u32 skb_prog_id;      /* output */
>> +       __u32 dequeue_prog_id;  /* output */
>
> can't do that, you have to put it after attach_mode to preserve
> backwards/forward compat

Argh, yes, of course, total brainfart - thanks for pointing that out! :)

-Toke