Re: [PATCH net-next V4 4/4] net/sched: Introduce act_tunnel_key

[Eric Dumazet]

On Wed, Aug 31, 2016 at 5:46 AM, Hadar Hen Zion <had...@mellanox.com> wrote:
>
> From: Amir Vadai <a...@vadai.me>
>
> This action could be used before redirecting packets to a shared tunnel
> device, or when redirecting packets arriving from a such a device.
>
>
> +
> +struct tcf_tunnel_key_params {
> +       struct rcu_head         rcu;
> +       int                     tcft_action;

Also add " int action;"

(see why later)

> +       struct metadata_dst     *tcft_enc_metadata;
> +};
> +



> +
> +static int tunnel_key_act(struct sk_buff *skb, const struct tc_action *a,
> +                         struct tcf_result *res)
> +{
> +       struct tcf_tunnel_key *t = to_tunnel_key(a);
> +       struct tcf_tunnel_key_params *params;
> +       int action;
> +
> +       rcu_read_lock();
> +
> +       params = rcu_dereference(t->params);
> +
> +       tcf_lastuse_update(&t->tcf_tm);
> +       bstats_cpu_update(this_cpu_ptr(t->common.cpu_bstats), skb);
> +       action = t->tcf_action;

Ideally, you should read param->action instead of t->tcf_action to be
completely clean.

> +
> +       switch (params->tcft_action) {
> +       case TCA_TUNNEL_KEY_ACT_RELEASE:
> +               skb_dst_drop(skb);
> +               break;
> +       case TCA_TUNNEL_KEY_ACT_SET:
> +               skb_dst_drop(skb);
> +               skb_dst_set(skb, dst_clone(&params->tcft_enc_metadata->dst));
> +               break;
> +       default:
> +               WARN_ONCE(1, "Bad tunnel_key action.\n");
> +               break;
> +       }
> +
> +       rcu_read_unlock();
> +
> +       return action;
> +}
>