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>

diff --git a/include/linux/if_bridge.h b/include/linux/if_bridge.h
index fd1b6eb..4ff211d 100644 (file)
--- 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 a260679..2f5c379 100644 (file)
--- 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 2b73de6..fab8ce0 100644 (file)
--- 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 d23972f..7f31d0f 100644 (file)
--- 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;