bonding: add xdp_features support

Introduce xdp_features support for bonding driver according to the slave
devices attached to the master one. xdp_features is required whenever we
want to xdp_redirect traffic into a bond device and then into selected
slaves attached to it.
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Acked-by: Jay Vosburgh <jay.vosburgh@canonical.com>
Fixes: 66c0e13a ("drivers: net: turn on XDP features")
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Reviewed-by: Jussi Maki <joamaki@gmail.com>
Tested-by: Jussi Maki <joamaki@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/bonding/bond_main.c

@@ -1789,6 +1789,26 @@ static void bond_ether_setup(struct net_device *bond_dev)
 	bond_dev->priv_flags &= ~IFF_TX_SKB_SHARING;
 }
 
+void bond_xdp_set_features(struct net_device *bond_dev)
+{
+	struct bonding *bond = netdev_priv(bond_dev);
+	xdp_features_t val = NETDEV_XDP_ACT_MASK;
+	struct list_head *iter;
+	struct slave *slave;
+
+	ASSERT_RTNL();
+
+	if (!bond_xdp_check(bond)) {
+		xdp_clear_features_flag(bond_dev);
+		return;
+	}
+
+	bond_for_each_slave(bond, slave, iter)
+		val &= slave->dev->xdp_features;
+
+	xdp_set_features_flag(bond_dev, val);
+}
+
 /* enslave device <slave> to bond device <master> */
 int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev,
 		 struct netlink_ext_ack *extack)
@@ -2236,6 +2256,8 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev,
 			bpf_prog_inc(bond->xdp_prog);
 	}
 
+	bond_xdp_set_features(bond_dev);
+
 	slave_info(bond_dev, slave_dev, "Enslaving as %s interface with %s link\n",
 		   bond_is_active_slave(new_slave) ? "an active" : "a backup",
 		   new_slave->link != BOND_LINK_DOWN ? "an up" : "a down");
@@ -2483,6 +2505,7 @@ static int __bond_release_one(struct net_device *bond_dev,
 	if (!netif_is_bond_master(slave_dev))
 		slave_dev->priv_flags &= ~IFF_BONDING;
 
+	bond_xdp_set_features(bond_dev);
 	kobject_put(&slave->kobj);
 
 	return 0;
@@ -3930,6 +3953,9 @@ static int bond_slave_netdev_event(unsigned long event,
 		/* Propagate to master device */
 		call_netdevice_notifiers(event, slave->bond->dev);
 		break;
+	case NETDEV_XDP_FEAT_CHANGE:
+		bond_xdp_set_features(bond_dev);
+		break;
 	default:
 		break;
 	}
@@ -5874,6 +5900,9 @@ void bond_setup(struct net_device *bond_dev)
 	if (BOND_MODE(bond) == BOND_MODE_ACTIVEBACKUP)
 		bond_dev->features |= BOND_XFRM_FEATURES;
 #endif /* CONFIG_XFRM_OFFLOAD */
+
+	if (bond_xdp_check(bond))
+		bond_dev->xdp_features = NETDEV_XDP_ACT_MASK;
 }
 
 /* Destroy a bonding device.

drivers/net/bonding/bond_options.c

@@ -877,6 +877,8 @@ static int bond_option_mode_set(struct bonding *bond,
 			netdev_update_features(bond->dev);
 	}
 
+	bond_xdp_set_features(bond->dev);
+
 	return 0;
 }
 

include/net/bonding.h

@@ -659,6 +659,7 @@ void bond_destroy_sysfs(struct bond_net *net);
 void bond_prepare_sysfs_group(struct bonding *bond);
 int bond_sysfs_slave_add(struct slave *slave);
 void bond_sysfs_slave_del(struct slave *slave);
+void bond_xdp_set_features(struct net_device *bond_dev);
 int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev,
 		 struct netlink_ext_ack *extack);
 int bond_release(struct net_device *bond_dev, struct net_device *slave_dev);