net: refactor ->ndo_bpf calls into dev_xdp_propagate

When net devices propagate xdp configurations to slave devices,
we will need to perform a memory provider check to ensure we're
not binding xdp to a device using unreadable netmem.

Currently the ->ndo_bpf calls in a few places. Adding checks to all
these places would not be ideal.

Refactor all the ->ndo_bpf calls into one place where we can add this
check in the future.
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Mina Almasry <almasrymina@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/bonding/bond_main.c

@@ -2253,7 +2253,7 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev,
 			goto err_sysfs_del;
 		}
 
-		res = slave_dev->netdev_ops->ndo_bpf(slave_dev, &xdp);
+		res = dev_xdp_propagate(slave_dev, &xdp);
 		if (res < 0) {
 			/* ndo_bpf() sets extack error message */
 			slave_dbg(bond_dev, slave_dev, "Error %d calling ndo_bpf\n", res);
@@ -2389,7 +2389,7 @@ static int __bond_release_one(struct net_device *bond_dev,
 			.prog	 = NULL,
 			.extack  = NULL,
 		};
-		if (slave_dev->netdev_ops->ndo_bpf(slave_dev, &xdp))
+		if (dev_xdp_propagate(slave_dev, &xdp))
 			slave_warn(bond_dev, slave_dev, "failed to unload XDP program\n");
 	}
 
@@ -5579,7 +5579,7 @@ static int bond_xdp_set(struct net_device *dev, struct bpf_prog *prog,
 			goto err;
 		}
 
-		err = slave_dev->netdev_ops->ndo_bpf(slave_dev, &xdp);
+		err = dev_xdp_propagate(slave_dev, &xdp);
 		if (err < 0) {
 			/* ndo_bpf() sets extack error message */
 			slave_err(dev, slave_dev, "Error %d calling ndo_bpf\n", err);
@@ -5611,7 +5611,7 @@ static int bond_xdp_set(struct net_device *dev, struct bpf_prog *prog,
 		if (slave == rollback_slave)
 			break;
 
-		err_unwind = slave_dev->netdev_ops->ndo_bpf(slave_dev, &xdp);
+		err_unwind = dev_xdp_propagate(slave_dev, &xdp);
 		if (err_unwind < 0)
 			slave_err(dev, slave_dev,
 				  "Error %d when unwinding XDP program change\n", err_unwind);

drivers/net/hyperv/netvsc_bpf.c

@@ -183,7 +183,7 @@ int netvsc_vf_setxdp(struct net_device *vf_netdev, struct bpf_prog *prog)
 	xdp.command = XDP_SETUP_PROG;
 	xdp.prog = prog;
 
-	ret = vf_netdev->netdev_ops->ndo_bpf(vf_netdev, &xdp);
+	ret = dev_xdp_propagate(vf_netdev, &xdp);
 
 	if (ret && prog)
 		bpf_prog_put(prog);

include/linux/netdevice.h

@@ -3925,6 +3925,7 @@ struct sk_buff *dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev,
 
 int bpf_xdp_link_attach(const union bpf_attr *attr, struct bpf_prog *prog);
 u8 dev_xdp_prog_count(struct net_device *dev);
+int dev_xdp_propagate(struct net_device *dev, struct netdev_bpf *bpf);
 u32 dev_xdp_prog_id(struct net_device *dev, enum bpf_xdp_mode mode);
 
 int __dev_forward_skb(struct net_device *dev, struct sk_buff *skb);

net/core/dev.c

@@ -9370,6 +9370,15 @@ u8 dev_xdp_prog_count(struct net_device *dev)
 }
 EXPORT_SYMBOL_GPL(dev_xdp_prog_count);
 
+int dev_xdp_propagate(struct net_device *dev, struct netdev_bpf *bpf)
+{
+	if (!dev->netdev_ops->ndo_bpf)
+		return -EOPNOTSUPP;
+
+	return dev->netdev_ops->ndo_bpf(dev, bpf);
+}
+EXPORT_SYMBOL_GPL(dev_xdp_propagate);
+
 u32 dev_xdp_prog_id(struct net_device *dev, enum bpf_xdp_mode mode)
 {
 	struct bpf_prog *prog = dev_xdp_prog(dev, mode);