macvlan: forbid L2 fowarding offload for macvtap

L2 fowarding offload will bypass the rx handler of real device. This will make
the packet could not be forwarded to macvtap device. Another problem is the
dev_hard_start_xmit() called for macvtap does not have any synchronization.

Fix this by forbidding L2 forwarding for macvtap.

Cc: John Fastabend <john.r.fastabend@intel.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Acked-by: John Fastabend <john.r.fastabend@intel.com.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
index 60406b01f9eb37b6a5728d18a72164b0a2598eb3..5360f73c9817f25b8b702c37da3e46111d6095ac 100644 (file)
--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -338,6 +338,8 @@ static const struct header_ops macvlan_hard_header_ops = {
        .cache_update   = eth_header_cache_update,
 };
 
+static struct rtnl_link_ops macvlan_link_ops;
+
 static int macvlan_open(struct net_device *dev)
 {
        struct macvlan_dev *vlan = netdev_priv(dev);
@@ -353,7 +355,8 @@ static int macvlan_open(struct net_device *dev)
                goto hash_add;
        }
 
-       if (lowerdev->features & NETIF_F_HW_L2FW_DOFFLOAD) {
+       if (lowerdev->features & NETIF_F_HW_L2FW_DOFFLOAD &&
+           dev->rtnl_link_ops == &macvlan_link_ops) {
                vlan->fwd_priv =
                      lowerdev->netdev_ops->ndo_dfwd_add_station(lowerdev, dev);