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

[Hangbin Liu <liuhangbin@gmail.com>]

On Wed, Aug 21, 2024 at 02:30:41PM +0200, Steffen Klassert wrote:
> > > +/**
> > > + * bond_advance_esn_state - ESN support for IPSec HW offload
> > > + * @xs: pointer to transformer state struct
> > > + **/
> > > +static void bond_advance_esn_state(struct xfrm_state *xs)
> > > +{
> > > +	struct net_device *real_dev;
> > > +
> > > +	rcu_read_lock();
> > > +	real_dev = bond_ipsec_dev(xs);
> > > +	if (!real_dev)
> > > +		goto out;
> > > +
> > > +	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.
> 
> How does xfrm_state offload work on bonding?
> Does every slave have its own negotiated SA?

Yes and no. Bonding only supports xfrm offload with active-backup mode. So only
current active slave keep the SA. When active slave changes, the sa on
previous slave is deleted and re-added on new active slave.

Thanks
Hangbin