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>

1 files changed, 55 insertions, 64 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index ffca5c1066fa..ec01a5998d70 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2604,70 +2604,14 @@ static inline int deliver_skb(struct sk_buff *skb,
         return pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
 }
 
-#if defined(CONFIG_BRIDGE) || defined (CONFIG_BRIDGE_MODULE)
-
-#if defined(CONFIG_ATM_LANE) || defined(CONFIG_ATM_LANE_MODULE)
+#if (defined(CONFIG_BRIDGE) || defined(CONFIG_BRIDGE_MODULE)) && \
+    (defined(CONFIG_ATM_LANE) || defined(CONFIG_ATM_LANE_MODULE))
 /* This hook is defined here for ATM LANE */
 int (*br_fdb_test_addr_hook)(struct net_device *dev,
                              unsigned char *addr) __read_mostly;
 EXPORT_SYMBOL_GPL(br_fdb_test_addr_hook);
 #endif
 
-/*
- * If bridge module is loaded call bridging hook.
- *  returns NULL if packet was consumed.
- */
-struct sk_buff *(*br_handle_frame_hook)(struct net_bridge_port *p,
-                                        struct sk_buff *skb) __read_mostly;
-EXPORT_SYMBOL_GPL(br_handle_frame_hook);
-
-static inline struct sk_buff *handle_bridge(struct sk_buff *skb,
-                                            struct packet_type **pt_prev, int *ret,
-                                            struct net_device *orig_dev)
-{
-        struct net_bridge_port *port;
-
-        if (skb->pkt_type == PACKET_LOOPBACK ||
-            (port = rcu_dereference(skb->dev->br_port)) == NULL)
-                return skb;
-
-        if (*pt_prev) {
-                *ret = deliver_skb(skb, *pt_prev, orig_dev);
-                *pt_prev = NULL;
-        }
-
-        return br_handle_frame_hook(port, skb);
-}
-#else
-#define handle_bridge(skb, pt_prev, ret, orig_dev)      (skb)
-#endif
-
-#if defined(CONFIG_MACVLAN) || defined(CONFIG_MACVLAN_MODULE)
-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,
-                                             struct packet_type **pt_prev,
-                                             int *ret,
-                                             struct net_device *orig_dev)
-{
-        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(port, skb);
-}
-#else
-#define handle_macvlan(skb, pt_prev, ret, orig_dev)     (skb)
-#endif
-
 #ifdef CONFIG_NET_CLS_ACT
 /* TODO: Maybe we should just force sch_ingress to be compiled in
  * when CONFIG_NET_CLS_ACT is? otherwise some useless instructions
@@ -2763,6 +2707,47 @@ void netif_nit_deliver(struct sk_buff *skb)
         rcu_read_unlock();
 }
 
+/**
+ *      netdev_rx_handler_register - register receive handler
+ *      @dev: device to register a handler for
+ *      @rx_handler: receive handler to register
+ *
+ *      Register a receive hander for a device. This handler will then be
+ *      called from __netif_receive_skb. A negative errno code is returned
+ *      on a failure.
+ *
+ *      The caller must hold the rtnl_mutex.
+ */
+int netdev_rx_handler_register(struct net_device *dev,
+                               rx_handler_func_t *rx_handler)
+{
+        ASSERT_RTNL();
+
+        if (dev->rx_handler)
+                return -EBUSY;
+
+        rcu_assign_pointer(dev->rx_handler, rx_handler);
+
+        return 0;
+}
+EXPORT_SYMBOL_GPL(netdev_rx_handler_register);
+
+/**
+ *      netdev_rx_handler_unregister - unregister receive handler
+ *      @dev: device to unregister a handler from
+ *
+ *      Unregister a receive hander from a device.
+ *
+ *      The caller must hold the rtnl_mutex.
+ */
+void netdev_rx_handler_unregister(struct net_device *dev)
+{
+
+        ASSERT_RTNL();
+        rcu_assign_pointer(dev->rx_handler, NULL);
+}
+EXPORT_SYMBOL_GPL(netdev_rx_handler_unregister);
+
 static inline void skb_bond_set_mac_by_master(struct sk_buff *skb,
                                               struct net_device *master)
 {
@@ -2815,6 +2800,7 @@ EXPORT_SYMBOL(__skb_bond_should_drop);
 static int __netif_receive_skb(struct sk_buff *skb)
 {
         struct packet_type *ptype, *pt_prev;
+        rx_handler_func_t *rx_handler;
         struct net_device *orig_dev;
         struct net_device *master;
         struct net_device *null_or_orig;
@@ -2877,12 +2863,17 @@ static int __netif_receive_skb(struct sk_buff *skb)
 ncls:
 #endif
 
-        skb = handle_bridge(skb, &pt_prev, &ret, orig_dev);
-        if (!skb)
-                goto out;
-        skb = handle_macvlan(skb, &pt_prev, &ret, orig_dev);
-        if (!skb)
-                goto out;
+        /* Handle special case of bridge or macvlan */
+        rx_handler = rcu_dereference(skb->dev->rx_handler);
+        if (rx_handler) {
+                if (pt_prev) {
+                        ret = deliver_skb(skb, pt_prev, orig_dev);
+                        pt_prev = NULL;
+                }
+                skb = rx_handler(skb);
+                if (!skb)
+                        goto out;
+        }
 
         /*
          * Make sure frames received on VLAN interfaces stacked on