net: replace hooks in __netif_receive_skb V5

What this patch does is it removes two receive frame hooks (for bridge and for
macvlan) from __netif_receive_skb. These are replaced them with a single
hook for both. It only supports one hook per device because it makes no
sense to do bridging and macvlan on the same device.

Then a network driver (of virtual netdev like macvlan or bridge) can register
an rx_handler for needed net device.

Signed-off-by: Jiri Pirko <jpirko@redhat.com>
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c
index d36e700..99647d8 100644
--- a/net/bridge/br_input.c
+++ b/net/bridge/br_input.c
@@ -131,15 +131,19 @@
 }
 
 /*
- * Called via br_handle_frame_hook.
  * Return NULL if skb is handled
- * note: already called with rcu_read_lock (preempt_disabled)
+ * note: already called with rcu_read_lock (preempt_disabled) from
+ * netif_receive_skb
  */
-struct sk_buff *br_handle_frame(struct net_bridge_port *p, struct sk_buff *skb)
+struct sk_buff *br_handle_frame(struct sk_buff *skb)
 {
+	struct net_bridge_port *p;
 	const unsigned char *dest = eth_hdr(skb)->h_dest;
 	int (*rhook)(struct sk_buff *skb);
 
+	if (skb->pkt_type == PACKET_LOOPBACK)
+		return skb;
+
 	if (!is_valid_ether_addr(eth_hdr(skb)->h_source))
 		goto drop;
 
@@ -147,6 +151,8 @@
 	if (!skb)
 		return NULL;
 
+	p = rcu_dereference(skb->dev->br_port);
+
 	if (unlikely(is_link_local(dest))) {
 		/* Pause frames shouldn't be passed up by driver anyway */
 		if (skb->protocol == htons(ETH_P_PAUSE))