Re: [PATCHv3 net-next 2/3] bonding: Add ESN support to IPSec HW offload

[Hangbin Liu <liuhangbin@gmail.com>]

On Tue, Aug 20, 2024 at 05:33:58PM +0200, Sabrina Dubroca wrote:
> > +	if (!real_dev->xfrmdev_ops ||
> > +	    !real_dev->xfrmdev_ops->xdo_dev_state_advance_esn) {
> > +		pr_warn("%s: %s doesn't support xdo_dev_state_advance_esn\n", __func__, real_dev->name);
> 
> xdo_dev_state_advance_esn is called on the receive path for every
> packet when ESN is enabled (xfrm_input -> xfrm_replay_advance ->
> xfrm_replay_advance_esn -> xfrm_dev_state_advance_esn), this needs to
> be ratelimited.

You are right. Warn on adding/deleting is OK. But during packets receiving
we need to limit it.

> 
> 
> But this CB is required to make offload with ESN work. If it's not
> implemented on a lower device, I expect things will break. I wonder
> what the best behavior would be:
> 
>  - just warn (this patch) -- but things will break for users

I would prefer this way, which is what we do currently. The warn could
let user know the ESN is not supported. They should use ESN supported device
or disable it.

Thanks
Hangbin