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

[Steffen Klassert <steffen.klassert@secunet.com>]

On Tue, Aug 20, 2024 at 05:33:58PM +0200, Sabrina Dubroca wrote:
> Hi Hangbin,
> 
> (adding Steffen since we're getting a bit into details of IPsec)
> 
> 2024-08-20, 08:48:39 +0800, Hangbin Liu wrote:
> > Currently, users can see that bonding supports IPSec HW offload via ethtool.
> > However, this functionality does not work with NICs like Mellanox cards when
> > ESN (Extended Sequence Numbers) is enabled, as ESN functions are not yet
> > supported. This patch adds ESN support to the bonding IPSec device offload,
> > ensuring proper functionality with NICs that support ESN.
> > 
> > Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
> > Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
> > ---
> >  drivers/net/bonding/bond_main.c | 25 +++++++++++++++++++++++++
> >  1 file changed, 25 insertions(+)
> > 
> > diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
> > index 560e3416f6f5..24747fceef66 100644
> > --- a/drivers/net/bonding/bond_main.c
> > +++ b/drivers/net/bonding/bond_main.c
> > @@ -651,10 +651,35 @@ static bool bond_ipsec_offload_ok(struct sk_buff *skb, struct xfrm_state *xs)
> >  	return err;
> >  }
> >  
> > +/**
> > + * 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?