kernel: bypass all netfilter hooks if the sysctls for that functionality have been disabled - eliminates the overhead of enabling CONFIG_BRIDGE_NETFILTER in the kernel config

SVN-Revision: 30917

1 files changed, 76 insertions, 0 deletions

diff --git a/target/linux/generic/patches-3.2/644-bridge_optimize_netfilter_hooks.patch b/target/linux/generic/patches-3.2/644-bridge_optimize_netfilter_hooks.patch
new file mode 100644
index 0000000..835d18d
--- /dev/null
+++ b/target/linux/generic/patches-3.2/644-bridge_optimize_netfilter_hooks.patch
@@ -0,0 +1,76 @@
+--- a/net/bridge/br_netfilter.c
++++ b/net/bridge/br_netfilter.c
+@@ -62,6 +62,11 @@ static int brnf_filter_pppoe_tagged __re
+ #define brnf_filter_pppoe_tagged 0
+ #endif
+ 
++bool br_netfilter_run_hooks(void)
++{
++	return brnf_call_iptables | brnf_call_ip6tables | brnf_call_arptables;
++}
++
+ static inline __be16 vlan_proto(const struct sk_buff *skb)
+ {
+ 	if (vlan_tx_tag_present(skb))
+--- a/net/bridge/br_private.h
++++ b/net/bridge/br_private.h
+@@ -491,10 +491,12 @@ static inline bool br_multicast_is_route
+ extern int br_netfilter_init(void);
+ extern void br_netfilter_fini(void);
+ extern void br_netfilter_rtable_init(struct net_bridge *);
++extern bool br_netfilter_run_hooks(void);
+ #else
+ #define br_netfilter_init()	(0)
+ #define br_netfilter_fini()	do { } while(0)
+ #define br_netfilter_rtable_init(x)
++#define br_netfilter_run_hooks()	false
+ #endif
+ 
+ /* br_stp.c */
+--- a/net/bridge/br_input.c
++++ b/net/bridge/br_input.c
+@@ -26,6 +26,17 @@ const u8 br_group_address[ETH_ALEN] = { 
+ br_should_route_hook_t __rcu *br_should_route_hook __read_mostly;
+ EXPORT_SYMBOL(br_should_route_hook);
+ 
++static inline int
++BR_HOOK(uint8_t pf, unsigned int hook, struct sk_buff *skb,
++	struct net_device *in, struct net_device *out,
++	int (*okfn)(struct sk_buff *))
++{
++	if (!br_netfilter_run_hooks())
++		return okfn(skb);
++
++	return NF_HOOK(pf, hook, skb, in, out, okfn);
++}
++
+ static int br_pass_frame_up(struct sk_buff *skb)
+ {
+ 	struct net_device *indev, *brdev = BR_INPUT_SKB_CB(skb)->brdev;
+@@ -40,7 +51,7 @@ static int br_pass_frame_up(struct sk_bu
+ 	indev = skb->dev;
+ 	skb->dev = brdev;
+ 
+-	return NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, skb, indev, NULL,
++	return BR_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, skb, indev, NULL,
+ 		       netif_receive_skb);
+ }
+ 
+@@ -199,7 +210,7 @@ rx_handler_result_t br_handle_frame(stru
+ 		}
+ 
+ 		/* Deliver packet to local host only */
+-		if (NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, skb, skb->dev,
++		if (BR_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, skb, skb->dev,
+ 			    NULL, br_handle_local_finish)) {
+ 			return RX_HANDLER_CONSUMED; /* consumed by filter */
+ 		} else {
+@@ -224,7 +235,7 @@ forward:
+ 		if (!compare_ether_addr(p->br->dev->dev_addr, dest))
+ 			skb->pkt_type = PACKET_HOST;
+ 
+-		NF_HOOK(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL,
++		BR_HOOK(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL,
+ 			br_handle_frame_finish);
+ 		break;
+ 	default: