+static int packet_direct_xmit(struct sk_buff *skb)
+{
+ struct net_device *dev = skb->dev;
+ const struct net_device_ops *ops = dev->netdev_ops;
+ netdev_features_t features;
+ struct netdev_queue *txq;
+ u16 queue_map;
+ int ret;
+
+ if (unlikely(!netif_running(dev) ||
+ !netif_carrier_ok(dev))) {
+ kfree_skb(skb);
+ return NET_XMIT_DROP;
+ }
+
+ features = netif_skb_features(skb);
+ if (skb_needs_linearize(skb, features) &&
+ __skb_linearize(skb)) {
+ kfree_skb(skb);
+ return NET_XMIT_DROP;
+ }
+
+ queue_map = skb_get_queue_mapping(skb);
+ txq = netdev_get_tx_queue(dev, queue_map);
+
+ __netif_tx_lock_bh(txq);
+ if (unlikely(netif_xmit_frozen_or_stopped(txq))) {
+ ret = NETDEV_TX_BUSY;
+ kfree_skb(skb);
+ goto out;
+ }
+
+ ret = ops->ndo_start_xmit(skb, dev);
+ if (likely(dev_xmit_complete(ret)))
+ txq_trans_update(txq);
+ else
+ kfree_skb(skb);
+out:
+ __netif_tx_unlock_bh(txq);
+ return ret;
+}
+
+static struct net_device *packet_cached_dev_get(struct packet_sock *po)
+{
+ struct net_device *dev;
+
+ rcu_read_lock();
+ dev = rcu_dereference(po->cached_dev);
+ if (likely(dev))
+ dev_hold(dev);
+ rcu_read_unlock();
+
+ return dev;
+}
+
+static void packet_cached_dev_assign(struct packet_sock *po,
+ struct net_device *dev)
+{
+ rcu_assign_pointer(po->cached_dev, dev);
+}
+
+static void packet_cached_dev_reset(struct packet_sock *po)
+{
+ RCU_INIT_POINTER(po->cached_dev, NULL);
+}
+
+static bool packet_use_direct_xmit(const struct packet_sock *po)
+{
+ return po->xmit == packet_direct_xmit;
+}
+
+static u16 packet_pick_tx_queue(struct net_device *dev)
+{
+ return (u16) smp_processor_id() % dev->real_num_tx_queues;
+}
+