Re: [PATCH net] Bonding: update bond device XFRM features based on current active slave

[Nikolay Aleksandrov <razor@blackwall.org>]

On 18/09/2024 11:35, Hangbin Liu wrote:
> XFRM offload is supported in active-backup mode. However, if the current
> active slave does not support it, we should disable it on bond device.
> Otherwise, ESP traffic may fail due to the downlink not supporting the
> feature.
> 
> Reproducer:
>   # ip link add bond0 type bond
>   # ip link add type veth
>   # ip link set bond0 type bond mode 1 miimon 100
>   # ip link set veth0 master bond0
>   # ethtool -k veth0 | grep esp
>   tx-esp-segmentation: off [fixed]
>   esp-hw-offload: off [fixed]
>   esp-tx-csum-hw-offload: off [fixed]
>   # ethtool -k bond0 | grep esp
>   tx-esp-segmentation: on
>   esp-hw-offload: on
>   esp-tx-csum-hw-offload: on
> 
> After fix:
>   # ethtool -k bond0 | grep esp
>   tx-esp-segmentation: off [requested on]
>   esp-hw-offload: off [requested on]
>   esp-tx-csum-hw-offload: off [requested on]
> 
> Fixes: a3b658cfb664 ("bonding: allow xfrm offload setup post-module-load")
> Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
> ---
>  drivers/net/bonding/bond_main.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
> index b560644ee1b1..33f7fde15c65 100644
> --- a/drivers/net/bonding/bond_main.c
> +++ b/drivers/net/bonding/bond_main.c
> @@ -1353,6 +1353,10 @@ void bond_change_active_slave(struct bonding *bond, struct slave *new_active)
>  				call_netdevice_notifiers(NETDEV_NOTIFY_PEERS,
>  							 bond->dev);
>  			}
> +
> +#ifdef CONFIG_XFRM_OFFLOAD
> +			netdev_update_features(bond->dev);
> +#endif /* CONFIG_XFRM_OFFLOAD */
>  		}
>  	}
>  
> @@ -1524,6 +1528,11 @@ static netdev_features_t bond_fix_features(struct net_device *dev,
>  		features = netdev_increment_features(features,
>  						     slave->dev->features,
>  						     mask);
> +#ifdef CONFIG_XFRM_OFFLOAD
> +		if (BOND_MODE(bond) == BOND_MODE_ACTIVEBACKUP &&
> +		    slave == rtnl_dereference(bond->curr_active_slave))
> +			features &= slave->dev->features & BOND_XFRM_FEATURES;
> +#endif /* CONFIG_XFRM_OFFLOAD */
>  	}
>  	features = netdev_add_tso_features(features, mask);
>  

Nice catch,
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>