Re: [PATCH net-next 1/2] ebpf: add sched_act_type and map it to sk_filter's verifier ops

[Alexei Starovoitov <ast@plumgrid.com>]

On 3/20/15 7:11 AM, Daniel Borkmann wrote:
> In order to prepare eBPF support for tc action, we need to add
> sched_act_type, so that the eBPF verifier is aware of what helper
> function act_bpf may use, that it can load skb data and read out
> currently available skb fields.
>
> This is bascially analogous to 96be4325f443 ("ebpf: add sched_cls_type
> and map it to sk_filter's verifier ops").
>
> BPF_PROG_TYPE_SCHED_CLS and BPF_PROG_TYPE_SCHED_ACT need to be
> separate since both will have a different set of functionality in
> future (classifier vs action), thus we won't run into ABI troubles
> when the point in time comes to diverge functionality from the
> classifier.
>
> The future plan for act_bpf would be that it will be able to write
> into skb->data and alter selected fields mirrored in struct __sk_buff.
>
> For an initial support, it's sufficient to map it to sk_filter_ops.
>
> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
> Cc: Jiri Pirko <jiri@resnulli.us>

Acked-by: Alexei Starovoitov <ast@plumgrid.com>