1 files changed, 18 insertions, 12 deletions

diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
index a98fb0e..ea53abb 100644
--- a/drivers/net/macvtap.c
+++ b/drivers/net/macvtap.c
@@ -68,6 +68,8 @@ static const struct proto_ops macvtap_socket_ops;
 #define TUN_OFFLOADS (NETIF_F_HW_CSUM | NETIF_F_TSO_ECN | NETIF_F_TSO | \
 		      NETIF_F_TSO6 | NETIF_F_UFO)
 #define RX_OFFLOADS (NETIF_F_GRO | NETIF_F_LRO)
+#define TAP_FEATURES (NETIF_F_GSO | NETIF_F_SG)
+
 /*
  * RCU usage:
  * The macvtap_queue and the macvlan_dev are loosely coupled, the
@@ -278,7 +280,8 @@ static int macvtap_forward(struct net_device *dev, struct sk_buff *skb)
 {
 	struct macvlan_dev *vlan = netdev_priv(dev);
 	struct macvtap_queue *q = macvtap_get_queue(dev, skb);
-	netdev_features_t features;
+	netdev_features_t features = TAP_FEATURES;
+
 	if (!q)
 		goto drop;
 
@@ -287,9 +290,11 @@ static int macvtap_forward(struct net_device *dev, struct sk_buff *skb)
 
 	skb->dev = dev;
 	/* Apply the forward feature mask so that we perform segmentation
-	 * according to users wishes.
+	 * according to users wishes.  This only works if VNET_HDR is
+	 * enabled.
 	 */
-	features = netif_skb_features(skb) & vlan->tap_features;
+	if (q->flags & IFF_VNET_HDR)
+		features |= vlan->tap_features;
 	if (netif_needs_gso(skb, features)) {
 		struct sk_buff *segs = __skb_gso_segment(skb, features, false);
 
@@ -818,10 +823,13 @@ static ssize_t macvtap_get_user(struct macvtap_queue *q, struct msghdr *m,
 		skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
 		skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
 	}
-	if (vlan)
+	if (vlan) {
+		local_bh_disable();
 		macvlan_start_xmit(skb, vlan->dev);
-	else
+		local_bh_enable();
+	} else {
 		kfree_skb(skb);
+	}
 	rcu_read_unlock();
 
 	return total_len;
@@ -912,8 +920,11 @@ static ssize_t macvtap_put_user(struct macvtap_queue *q,
 done:
 	rcu_read_lock();
 	vlan = rcu_dereference(q->vlan);
-	if (vlan)
+	if (vlan) {
+		preempt_disable();
 		macvlan_count_rx(vlan, copied - vnet_hdr_len, ret == 0, 0);
+		preempt_enable();
+	}
 	rcu_read_unlock();
 
 	return ret ? ret : copied;
@@ -1058,8 +1069,7 @@ static int set_offload(struct macvtap_queue *q, unsigned long arg)
 	/* tap_features are the same as features on tun/tap and
 	 * reflect user expectations.
 	 */
-	vlan->tap_features = vlan->dev->features &
-			    (feature_mask | ~TUN_OFFLOADS);
+	vlan->tap_features = feature_mask;
 	vlan->set_features = features;
 	netdev_update_features(vlan->dev);
 
@@ -1155,10 +1165,6 @@ static long macvtap_ioctl(struct file *file, unsigned int cmd,
 			    TUN_F_TSO_ECN | TUN_F_UFO))
 			return -EINVAL;
 
-		/* TODO: only accept frames with the features that
-			 got enabled for forwarded frames */
-		if (!(q->flags & IFF_VNET_HDR))
-			return  -EINVAL;
 		rtnl_lock();
 		ret = set_offload(q, arg);
 		rtnl_unlock();