net: convert bridge_nf to use skb extension infrastructure

This converts the bridge netfilter (calling iptables hooks from bridge)
facility to use the extension infrastructure.

The bridge_nf specific hooks in skb clone and free paths are removed, they
have been replaced by the skb_ext hooks that do the same as the bridge nf
allocations hooks did.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 8 insertions, 32 deletions

diff --git a/include/linux/netfilter_bridge.h b/include/linux/netfilter_bridge.h
index 0a65a422587c..5f2614d02e03 100644
--- a/include/linux/netfilter_bridge.h
+++ b/include/linux/netfilter_bridge.h
@@ -20,12 +20,12 @@ static inline void br_drop_fake_rtable(struct sk_buff *skb)
 static inline struct nf_bridge_info *
 nf_bridge_info_get(const struct sk_buff *skb)
 {
-	return skb->nf_bridge;
+	return skb_ext_find(skb, SKB_EXT_BRIDGE_NF);
 }
 
 static inline bool nf_bridge_info_exists(const struct sk_buff *skb)
 {
-	return skb->nf_bridge != NULL;
+	return skb_ext_exist(skb, SKB_EXT_BRIDGE_NF);
 }
 
 static inline int nf_bridge_get_physinif(const struct sk_buff *skb)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 88f7541837e3..2f42d2e99f17 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -255,7 +255,6 @@ struct nf_conntrack {
 
 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
 struct nf_bridge_info {
-	refcount_t		use;
 	enum {
 		BRNF_PROTO_UNCHANGED,
 		BRNF_PROTO_8021Q,
@@ -721,9 +720,6 @@ struct sk_buff {
 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
 	unsigned long		 _nfct;
 #endif
-#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
-	struct nf_bridge_info	*nf_bridge;
-#endif
 	unsigned int		len,
 				data_len;
 	__u16			mac_len,
@@ -4005,18 +4001,6 @@ static inline void __skb_ext_copy(struct sk_buff *d, const struct sk_buff *s) {}
 static inline void skb_ext_copy(struct sk_buff *dst, const struct sk_buff *s) {}
 #endif /* CONFIG_SKB_EXTENSIONS */
 
-#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
-static inline void nf_bridge_put(struct nf_bridge_info *nf_bridge)
-{
-	if (nf_bridge && refcount_dec_and_test(&nf_bridge->use))
-		kfree(nf_bridge);
-}
-static inline void nf_bridge_get(struct nf_bridge_info *nf_bridge)
-{
-	if (nf_bridge)
-		refcount_inc(&nf_bridge->use);
-}
-#endif /* CONFIG_BRIDGE_NETFILTER */
 static inline void nf_reset(struct sk_buff *skb)
 {
 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
@@ -4024,8 +4008,7 @@ static inline void nf_reset(struct sk_buff *skb)
 	skb->_nfct = 0;
 #endif
 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
-	nf_bridge_put(skb->nf_bridge);
-	skb->nf_bridge = NULL;
+	skb_ext_del(skb, SKB_EXT_BRIDGE_NF);
 #endif
 }
 
@@ -4043,7 +4026,7 @@ static inline void ipvs_reset(struct sk_buff *skb)
 #endif
 }
 
-/* Note: This doesn't put any conntrack and bridge info in dst. */
+/* Note: This doesn't put any conntrack info in dst. */
 static inline void __nf_copy(struct sk_buff *dst, const struct sk_buff *src,
 			     bool copy)
 {
@@ -4051,10 +4034,6 @@ static inline void __nf_copy(struct sk_buff *dst, const struct sk_buff *src,
 	dst->_nfct = src->_nfct;
 	nf_conntrack_get(skb_nfct(src));
 #endif
-#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
-	dst->nf_bridge  = src->nf_bridge;
-	nf_bridge_get(src->nf_bridge);
-#endif
 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || defined(CONFIG_NF_TABLES)
 	if (copy)
 		dst->nf_trace = src->nf_trace;
@@ -4066,9 +4045,6 @@ static inline void nf_copy(struct sk_buff *dst, const struct sk_buff *src)
 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
 	nf_conntrack_put(skb_nfct(dst));
 #endif
-#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
-	nf_bridge_put(dst->nf_bridge);
-#endif
 	__nf_copy(dst, src, true);
 }
 
diff --git a/include/net/netfilter/br_netfilter.h b/include/net/netfilter/br_netfilter.h
index 6efc0153987b..4cd56808ac4e 100644
--- a/include/net/netfilter/br_netfilter.h
+++ b/include/net/netfilter/br_netfilter.h
@@ -6,12 +6,12 @@
 
 static inline struct nf_bridge_info *nf_bridge_alloc(struct sk_buff *skb)
 {
-	skb->nf_bridge = kzalloc(sizeof(struct nf_bridge_info), GFP_ATOMIC);
+	struct nf_bridge_info *b = skb_ext_add(skb, SKB_EXT_BRIDGE_NF);
 
-	if (likely(skb->nf_bridge))
-		refcount_set(&(skb->nf_bridge->use), 1);
+	if (b)
+		memset(b, 0, sizeof(*b));
 
-	return skb->nf_bridge;
+	return b;
 }
 
 void nf_bridge_update_protocol(struct sk_buff *skb);