Subject: Re: [Patch net-next] net_sched: act: fix a bug in tcf_register_action()

From: Jamal Hadi Salim <[email-masked]>
Date: Wed, 15 Jan 2014 07:34:49 -0500

On 01/14/14 17:48, Cong Wang wrote:
> In tcf_register_action() we check ->type and ->kind to see if there
> is an existing action registered, but ipt action registers two
> actions with same type but different kinds. This should be a valid
> case, otherwise only xt can be registered.
>

We cant allow for conflicts by name or id - we want to catch them.
So just introduce TCA_ACT_XT instead (ID 7)

[
Note: iptables used to be a constant moving API target
and this is supposed to be the latest "backward compat mode".
New kernel/iproute ==> We want to love "xt" more than "ipt".
We infact want to eventually kill "ipt".
but this preference is hard to achieve as you may have run into.
I would be curious how you tested and run into this..
].

cheers,
jamal

> Cc: Jamal Hadi Salim <[email-masked]>
> Cc: David S. Miller <[email-masked]>
> Signed-off-by: Cong Wang <[email-masked]>
>
> ---
> diff --git a/net/sched/act_api.c b/net/sched/act_api.c
> index 35f89e9..2070ee3 100644
> --- a/net/sched/act_api.c
> +++ b/net/sched/act_api.c
> @@ -273,7 +273,7 @@ int tcf_register_action(struct tc_action_ops *act)
>
>   	write_lock(&act_mod_lock);
>   	list_for_each_entry(a, &act_base, head) {
> -		if (act->type == a->type || (strcmp(act->kind, a->kind) == 0)) {
> +		if (act->type == a->type && (strcmp(act->kind, a->kind) == 0)) {
>   			write_unlock(&act_mod_lock);
>   			return -EEXIST;
>   		}
>