net: disallow drivers with buggy VLAN accel to register_netdevice()

Instead of jumping aroung bugs that are easily fixed just don't let them in:
affected drivers should be either fixed or have NETIF_F_HW_VLAN_FILTER
removed from advertised features.

Quick grep in drivers/net shows two drivers that have NETIF_F_HW_VLAN_FILTER
but not ndo_vlan_rx_add/kill_vid(), but those are false-positives (features
are commented out).

OTOH two drivers have ndo_vlan_rx_add/kill_vid() implemented but don't
advertise NETIF_F_HW_VLAN_FILTER. Those are:

+ethernet/cisco/enic/enic_main.c
+ethernet/qlogic/qlcnic/qlcnic_main.c

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 10 insertions, 11 deletions

diff --git a/net/8021q/vlan.c b/net/8021q/vlan.c
index babfde9f734c..addc578d5443 100644
--- a/net/8021q/vlan.c
+++ b/net/8021q/vlan.c
@@ -117,19 +117,12 @@ void unregister_vlan_dev(struct net_device *dev, struct list_head *head)
 int vlan_check_real_dev(struct net_device *real_dev, u16 vlan_id)
 {
         const char *name = real_dev->name;
-        const struct net_device_ops *ops = real_dev->netdev_ops;
 
         if (real_dev->features & NETIF_F_VLAN_CHALLENGED) {
                 pr_info("VLANs not supported on %s\n", name);
                 return -EOPNOTSUPP;
         }
 
-        if ((real_dev->features & NETIF_F_HW_VLAN_FILTER) &&
-            (!ops->ndo_vlan_rx_add_vid || !ops->ndo_vlan_rx_kill_vid)) {
-                pr_info("Device %s has buggy VLAN hw accel\n", name);
-                return -EOPNOTSUPP;
-        }
-
         if (vlan_find_dev(real_dev, vlan_id) != NULL)
                 return -EEXIST;
 
diff --git a/net/8021q/vlan_core.c b/net/8021q/vlan_core.c
index 380440b8ea89..71b64fde8dc9 100644
--- a/net/8021q/vlan_core.c
+++ b/net/8021q/vlan_core.c
@@ -224,8 +224,7 @@ static int __vlan_vid_add(struct vlan_info *vlan_info, unsigned short vid,
         if (!vid_info)
                 return -ENOMEM;
 
-        if ((dev->features & NETIF_F_HW_VLAN_FILTER) &&
-            ops->ndo_vlan_rx_add_vid) {
+        if (dev->features & NETIF_F_HW_VLAN_FILTER) {
                 err =  ops->ndo_vlan_rx_add_vid(dev, vid);
                 if (err) {
                         kfree(vid_info);
@@ -282,8 +281,7 @@ static void __vlan_vid_del(struct vlan_info *vlan_info,
         unsigned short vid = vid_info->vid;
         int err;
 
-        if ((dev->features & NETIF_F_HW_VLAN_FILTER) &&
-             ops->ndo_vlan_rx_kill_vid) {
+        if (dev->features & NETIF_F_HW_VLAN_FILTER) {
                 err = ops->ndo_vlan_rx_kill_vid(dev, vid);
                 if (err) {
                         pr_warn("failed to kill vid %d for device %s\n",
diff --git a/net/core/dev.c b/net/core/dev.c
index a83375d3af72..a87bc74e9fd0 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -6054,6 +6054,14 @@ int register_netdevice(struct net_device *dev)
                 }
         }
 
+        if (((dev->hw_features | dev->features) & NETIF_F_HW_VLAN_FILTER) &&
+            (!dev->netdev_ops->ndo_vlan_rx_add_vid ||
+             !dev->netdev_ops->ndo_vlan_rx_kill_vid)) {
+                netdev_WARN(dev, "Buggy VLAN acceleration in driver!\n");
+                ret = -EINVAL;
+                goto err_uninit;
+        }
+
         ret = -EBUSY;
         if (!dev->ifindex)
                 dev->ifindex = dev_new_index(net);