static int packet_direct_xmit(struct sk_buff *skb)
{
	struct net_device *dev = skb->dev;
	struct sk_buff *orig_skb = skb;
	struct netdev_queue *txq;
	int ret = NETDEV_TX_BUSY;

	if (unlikely(!netif_running(dev) ||
		     !netif_carrier_ok(dev)))
		goto drop;

	skb = validate_xmit_skb_list(skb, dev);
	if (skb != orig_skb)
		goto drop;

	txq = skb_get_tx_queue(dev, skb);

	local_bh_disable();

	HARD_TX_LOCK(dev, txq, smp_processor_id());
	if (!netif_xmit_frozen_or_drv_stopped(txq))
		ret = netdev_start_xmit(skb, dev, txq, false);
	HARD_TX_UNLOCK(dev, txq);

	local_bh_enable();

	if (!dev_xmit_complete(ret))
		kfree_skb(skb);

	return ret;
drop:
	atomic_long_inc(&dev->tx_dropped);
	kfree_skb_list(skb);
	return NET_XMIT_DROP;
}
Unknown