net: introduce IFF_NO_RX_HANDLER

Some network devices - notably ipvlan slave - are not compatible with
any kind of rx_handler. Currently the hook can be installed but any
configuration (bridge, bond, macsec, ...) is nonfunctional.

This change allocates a priv_flag bit to mark such devices and explicitly
forbid installing a rx_handler if such bit is set. The new bit is used
by ipvlan slave device.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ipvlan/ipvlan_main.c b/drivers/net/ipvlan/ipvlan_main.c
index 23fd5ab..743d37f 100644 (file)
--- a/drivers/net/ipvlan/ipvlan_main.c
+++ b/drivers/net/ipvlan/ipvlan_main.c
@@ -604,6 +604,8 @@ int ipvlan_link_new(struct net *src_net, struct net_device *dev,
         */
        memcpy(dev->dev_addr, phy_dev->dev_addr, ETH_ALEN);
 
+       dev->priv_flags |= IFF_NO_RX_HANDLER;
+
        err = register_netdevice(dev);
        if (err < 0)
                return err;

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 9711108..5fbb9f1 100644 (file)
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1397,6 +1397,7 @@ struct net_device_ops {
  * @IFF_PHONY_HEADROOM: the headroom value is controlled by an external
  *     entity (i.e. the master device for bridged veth)
  * @IFF_MACSEC: device is a MACsec device
+ * @IFF_NO_RX_HANDLER: device doesn't support the rx_handler hook
  */
 enum netdev_priv_flags {
        IFF_802_1Q_VLAN                 = 1<<0,
@@ -1425,6 +1426,7 @@ enum netdev_priv_flags {
        IFF_RXFH_CONFIGURED             = 1<<23,
        IFF_PHONY_HEADROOM              = 1<<24,
        IFF_MACSEC                      = 1<<25,
+       IFF_NO_RX_HANDLER               = 1<<26,
 };
 
 #define IFF_802_1Q_VLAN                        IFF_802_1Q_VLAN
@@ -1452,6 +1454,7 @@ enum netdev_priv_flags {
 #define IFF_TEAM                       IFF_TEAM
 #define IFF_RXFH_CONFIGURED            IFF_RXFH_CONFIGURED
 #define IFF_MACSEC                     IFF_MACSEC
+#define IFF_NO_RX_HANDLER              IFF_NO_RX_HANDLER
 
 /**
  *     struct net_device - The DEVICE structure.

diff --git a/net/core/dev.c b/net/core/dev.c
index e5b8d42..259abb1 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4351,6 +4351,9 @@ int netdev_rx_handler_register(struct net_device *dev,
        if (netdev_is_rx_handler_busy(dev))
                return -EBUSY;
 
+       if (dev->priv_flags & IFF_NO_RX_HANDLER)
+               return -EINVAL;
+
        /* Note: rx_handler_data must be set before rx_handler */
        rcu_assign_pointer(dev->rx_handler_data, rx_handler_data);
        rcu_assign_pointer(dev->rx_handler, rx_handler);