bridge: eliminate call by reference

Change the bridging hook to be simple function with return value
rather than modifying the skb argument. This could generate better
code and is cleaner.

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>

4 files changed, 32 insertions, 25 deletions

diff --git a/include/linux/if_bridge.h b/include/linux/if_bridge.h
index fd1b6eb94a5f..4ff211d98769 100644
--- a/include/linux/if_bridge.h
+++ b/include/linux/if_bridge.h
@@ -105,7 +105,8 @@ struct __fdb_entry
 #include <linux/netdevice.h>
 
 extern void brioctl_set(int (*ioctl_hook)(unsigned int, void __user *));
-extern int (*br_handle_frame_hook)(struct net_bridge_port *p, struct sk_buff **pskb);
+extern struct sk_buff *(*br_handle_frame_hook)(struct net_bridge_port *p,
+                                               struct sk_buff *skb);
 extern int (*br_should_route_hook)(struct sk_buff **pskb);
 
 #endif
diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c
index a260679afad8..2f5c379d9ffa 100644
--- a/net/bridge/br_input.c
+++ b/net/bridge/br_input.c
@@ -121,13 +121,11 @@ static inline int is_link_local(const unsigned char *dest)
 
 /*
  * Called via br_handle_frame_hook.
- * Return 0 if *pskb should be processed furthur
- *        1 if *pskb is handled
+ * Return NULL if skb is handled
  * note: already called with rcu_read_lock (preempt_disabled)
  */
-int br_handle_frame(struct net_bridge_port *p, struct sk_buff **pskb)
+struct sk_buff *br_handle_frame(struct net_bridge_port *p, struct sk_buff *skb)
 {
-        struct sk_buff *skb = *pskb;
         const unsigned char *dest = eth_hdr(skb)->h_dest;
 
         if (!is_valid_ether_addr(eth_hdr(skb)->h_source))
@@ -135,15 +133,15 @@ int br_handle_frame(struct net_bridge_port *p, struct sk_buff **pskb)
 
         if (unlikely(is_link_local(dest))) {
                 skb->pkt_type = PACKET_HOST;
-                return NF_HOOK(PF_BRIDGE, NF_BR_LOCAL_IN, skb, skb->dev,
-                               NULL, br_handle_local_finish) != 0;
+
+                return (NF_HOOK(PF_BRIDGE, NF_BR_LOCAL_IN, skb, skb->dev,
+                                NULL, br_handle_local_finish) == 0) ? skb : NULL;
         }
 
         if (p->state == BR_STATE_FORWARDING || p->state == BR_STATE_LEARNING) {
                 if (br_should_route_hook) {
-                        if (br_should_route_hook(pskb))
-                                return 0;
-                        skb = *pskb;
+                        if (br_should_route_hook(&skb))
+                                return skb;
                         dest = eth_hdr(skb)->h_dest;
                 }
 
@@ -152,10 +150,10 @@ int br_handle_frame(struct net_bridge_port *p, struct sk_buff **pskb)
 
                 NF_HOOK(PF_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL,
                         br_handle_frame_finish);
-                return 1;
+                return NULL;
         }
 
 err:
         kfree_skb(skb);
-        return 1;
+        return NULL;
 }
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 2b73de6c0b47..fab8ce0ce88d 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -182,7 +182,8 @@ extern void br_features_recompute(struct net_bridge *br);
 
 /* br_input.c */
 extern int br_handle_frame_finish(struct sk_buff *skb);
-extern int br_handle_frame(struct net_bridge_port *p, struct sk_buff **pskb);
+extern struct sk_buff *br_handle_frame(struct net_bridge_port *p,
+                                       struct sk_buff *skb);
 
 /* br_ioctl.c */
 extern int br_dev_ioctl(struct net_device *dev, struct ifreq *rq, int cmd);
diff --git a/net/core/dev.c b/net/core/dev.c
index d23972f56fc7..7f31d0f88424 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1687,31 +1687,37 @@ static inline int deliver_skb(struct sk_buff *skb,
 }
 
 #if defined(CONFIG_BRIDGE) || defined (CONFIG_BRIDGE_MODULE)
-int (*br_handle_frame_hook)(struct net_bridge_port *p, struct sk_buff **pskb);
+/* These hooks defined here for ATM */
 struct net_bridge;
 struct net_bridge_fdb_entry *(*br_fdb_get_hook)(struct net_bridge *br,
                                                 unsigned char *addr);
-void (*br_fdb_put_hook)(struct net_bridge_fdb_entry *ent);
+void (*br_fdb_put_hook)(struct net_bridge_fdb_entry *ent) __read_mostly;
 
-static __inline__ int handle_bridge(struct sk_buff **pskb,
-                                    struct packet_type **pt_prev, int *ret,
-                                    struct net_device *orig_dev)
+/*
+ * 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;
+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 ((*pskb)->pkt_type == PACKET_LOOPBACK ||
-            (port = rcu_dereference((*pskb)->dev->br_port)) == NULL)
-                return 0;
+        if (skb->pkt_type == PACKET_LOOPBACK ||
+            (port = rcu_dereference(skb->dev->br_port)) == NULL)
+                return skb;
 
         if (*pt_prev) {
-                *ret = deliver_skb(*pskb, *pt_prev, orig_dev);
+                *ret = deliver_skb(skb, *pt_prev, orig_dev);
                 *pt_prev = NULL;
         }
 
-        return br_handle_frame_hook(port, pskb);
+        return br_handle_frame_hook(port, skb);
 }
 #else
-#define handle_bridge(skb, pt_prev, ret, orig_dev)      (0)
+#define handle_bridge(skb, pt_prev, ret, orig_dev)      (skb)
 #endif
 
 #ifdef CONFIG_NET_CLS_ACT
@@ -1818,7 +1824,8 @@ int netif_receive_skb(struct sk_buff *skb)
 ncls:
 #endif
 
-        if (handle_bridge(&skb, &pt_prev, &ret, orig_dev))
+        skb = handle_bridge(skb, &pt_prev, &ret, orig_dev);
+        if (!skb)
                 goto out;
 
         type = skb->protocol;