[VLAN]: Propagate selected feature bits to VLAN devices

Propagate feature bits from the NETDEV_FEAT_CHANGE notifier. For now
only TSO is propagated for devices that announce their ability to
support TSO in combination with VLAN accel by setting the NETIF_F_VLAN_TSO
flag.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 30 insertions, 0 deletions

diff --git a/net/8021q/vlan.c b/net/8021q/vlan.c
index b934159a6f07..51961300b586 100644
--- a/net/8021q/vlan.c
+++ b/net/8021q/vlan.c
@@ -382,6 +382,24 @@ static void vlan_sync_address(struct net_device *dev,
         memcpy(vlan->real_dev_addr, dev->dev_addr, ETH_ALEN);
 }
 
+static void vlan_transfer_features(struct net_device *dev,
+                                   struct net_device *vlandev)
+{
+        unsigned long old_features = vlandev->features;
+
+        if (dev->features & NETIF_F_VLAN_TSO) {
+                vlandev->features &= ~VLAN_TSO_FEATURES;
+                vlandev->features |= dev->features & VLAN_TSO_FEATURES;
+        }
+        if (dev->features & NETIF_F_VLAN_CSUM) {
+                vlandev->features &= ~NETIF_F_ALL_CSUM;
+                vlandev->features |= dev->features & NETIF_F_ALL_CSUM;
+        }
+
+        if (old_features != vlandev->features)
+                netdev_features_change(vlandev);
+}
+
 static void __vlan_device_event(struct net_device *dev, unsigned long event)
 {
         switch (event) {
@@ -448,6 +466,18 @@ static int vlan_device_event(struct notifier_block *unused, unsigned long event,
                 }
                 break;
 
+        case NETDEV_FEAT_CHANGE:
+                /* Propagate device features to underlying device */
+                for (i = 0; i < VLAN_GROUP_ARRAY_LEN; i++) {
+                        vlandev = vlan_group_get_device(grp, i);
+                        if (!vlandev)
+                                continue;
+
+                        vlan_transfer_features(dev, vlandev);
+                }
+
+                break;
+
         case NETDEV_DOWN:
                 /* Put all VLANs for this dev in the down state too.  */
                 for (i = 0; i < VLAN_GROUP_ARRAY_LEN; i++) {