Re: [PATCH bpf-next 2/3] bpf: Add support for writing to nf_conn:mark

[Daniel Xu]

Hi Toke,

On Mon, Aug 15, 2022, at 4:25 PM, Toke Høiland-Jørgensen wrote:
> Daniel Xu <dxu@xxxxxxxxx> writes:
>
>> Support direct writes to nf_conn:mark from TC and XDP prog types. This
>> is useful when applications want to store per-connection metadata. This
>> is also particularly useful for applications that run both bpf and
>> iptables/nftables because the latter can trivially access this metadata.
>>
>> One example use case would be if a bpf prog is responsible for advanced
>> packet classification and iptables/nftables is later used for routing
>> due to pre-existing/legacy code.
>>
>> Signed-off-by: Daniel Xu <dxu@xxxxxxxxx>
>
> Didn't we agree the last time around that all field access should be
> using helper kfuncs instead of allowing direct writes to struct nf_conn?

Sorry, I was not aware of those discussions. Do you have a link handy?

I received the suggestion to enable direct writes here:
https://lore.kernel.org/bpf/CAP01T74aWUW-iyPCV_VfASO6YqfAZmnkYQMN2B4L8ngMMgnAcw@xxxxxxxxxxxxxx/ .

Thanks,
Daniel