openvswitch: Use dev_queue_xmit for vport send.

With use of lwtunnel, we can directly call dev_queue_xmit()
rather than calling netdev vport send operation.
Following change make tunnel vport code bit cleaner.

Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Acked-by: Thomas Graf <tgraf@suug.ch>
Acked-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/openvswitch/vport.c b/net/openvswitch/vport.c
index 12a36ac2..ef19d0b 100644
--- a/net/openvswitch/vport.c
+++ b/net/openvswitch/vport.c
@@ -537,3 +537,33 @@
 
 	return vport->ops->get_egress_tun_info(vport, skb, upcall);
 }
+
+static unsigned int packet_length(const struct sk_buff *skb)
+{
+	unsigned int length = skb->len - ETH_HLEN;
+
+	if (skb->protocol == htons(ETH_P_8021Q))
+		length -= VLAN_HLEN;
+
+	return length;
+}
+
+void ovs_vport_send(struct vport *vport, struct sk_buff *skb)
+{
+	int mtu = vport->dev->mtu;
+
+	if (unlikely(packet_length(skb) > mtu && !skb_is_gso(skb))) {
+		net_warn_ratelimited("%s: dropped over-mtu packet: %d > %d\n",
+				     vport->dev->name,
+				     packet_length(skb), mtu);
+		vport->dev->stats.tx_errors++;
+		goto drop;
+	}
+
+	skb->dev = vport->dev;
+	vport->ops->send(skb);
+	return;
+
+drop:
+	kfree_skb(skb);
+}