net: adjust handle_macvlan to pass port struct to hook

Now there's null check here and also again in the hook. Looking at bridge bits
which are simmilar, port structure is rcu_dereferenced right away in
handle_bridge and passed to hook. Looks nicer.

Signed-off-by: Jiri Pirko <jpirko@redhat.com>
Acked-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/macvlan.c

@@ -145,19 +145,15 @@ static void macvlan_broadcast(struct sk_buff *skb,
 }
 
 /* called under rcu_read_lock() from netif_receive_skb */
-static struct sk_buff *macvlan_handle_frame(struct sk_buff *skb)
+static struct sk_buff *macvlan_handle_frame(struct macvlan_port *port,
+					    struct sk_buff *skb)
 {
 	const struct ethhdr *eth = eth_hdr(skb);
-	const struct macvlan_port *port;
 	const struct macvlan_dev *vlan;
 	const struct macvlan_dev *src;
 	struct net_device *dev;
 	unsigned int len;
 
-	port = rcu_dereference(skb->dev->macvlan_port);
-	if (port == NULL)
-		return skb;
-
 	if (is_multicast_ether_addr(eth->h_dest)) {
 		src = macvlan_hash_lookup(port, eth->h_source);
 		if (!src)

include/linux/if_macvlan.h

@@ -85,6 +85,7 @@ extern netdev_tx_t macvlan_start_xmit(struct sk_buff *skb,
 				      struct net_device *dev);
 
 
-extern struct sk_buff *(*macvlan_handle_frame_hook)(struct sk_buff *);
+extern struct sk_buff *(*macvlan_handle_frame_hook)(struct macvlan_port *,
+						    struct sk_buff *);
 
 #endif /* _LINUX_IF_MACVLAN_H */

net/core/dev.c

@@ -2612,7 +2612,8 @@ static inline struct sk_buff *handle_bridge(struct sk_buff *skb,
 #endif
 
 #if defined(CONFIG_MACVLAN) || defined(CONFIG_MACVLAN_MODULE)
-struct sk_buff *(*macvlan_handle_frame_hook)(struct sk_buff *skb) __read_mostly;
+struct sk_buff *(*macvlan_handle_frame_hook)(struct macvlan_port *p,
+					     struct sk_buff *skb) __read_mostly;
 EXPORT_SYMBOL_GPL(macvlan_handle_frame_hook);
 
 static inline struct sk_buff *handle_macvlan(struct sk_buff *skb,
@@ -2620,14 +2621,17 @@ static inline struct sk_buff *handle_macvlan(struct sk_buff *skb,
 					     int *ret,
 					     struct net_device *orig_dev)
 {
-	if (skb->dev->macvlan_port == NULL)
+	struct macvlan_port *port;
+
+	port = rcu_dereference(skb->dev->macvlan_port);
+	if (!port)
 		return skb;
 
 	if (*pt_prev) {
 		*ret = deliver_skb(skb, *pt_prev, orig_dev);
 		*pt_prev = NULL;
 	}
-	return macvlan_handle_frame_hook(skb);
+	return macvlan_handle_frame_hook(port, skb);
 }
 #else
 #define handle_macvlan(skb, pt_prev, ret, orig_dev)	(skb)