[PATCH nf-next 3/7] netfilter: nft_objref: add nft_obj_ref structure and use it

[Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>]

This allows to extend this private expression area with new fields.

Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
 include/net/netfilter/nf_tables.h |  4 ++++
 net/netfilter/nft_objref.c        | 22 ++++++++++++----------
 2 files changed, 16 insertions(+), 10 deletions(-)

diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h
index 87b758407868..04c3b2e7eb99 100644
--- a/include/net/netfilter/nf_tables.h
+++ b/include/net/netfilter/nf_tables.h
@@ -1122,6 +1122,10 @@ struct nft_object_type {
 	const struct nla_policy		*policy;
 };
 
+struct nft_object_ref {
+	struct nft_object		*obj;
+};
+
 /**
  *	struct nft_object_ops - stateful object operations
  *
diff --git a/net/netfilter/nft_objref.c b/net/netfilter/nft_objref.c
index 006c2ebd898a..c9d8543fc97c 100644
--- a/net/netfilter/nft_objref.c
+++ b/net/netfilter/nft_objref.c
@@ -11,23 +11,22 @@
 #include <linux/netfilter/nf_tables.h>
 #include <net/netfilter/nf_tables.h>
 
-#define nft_objref_priv(expr)	*((struct nft_object **)nft_expr_priv(expr))
-
 static void nft_objref_eval(const struct nft_expr *expr,
 			    struct nft_regs *regs,
 			    const struct nft_pktinfo *pkt)
 {
-	struct nft_object *obj = nft_objref_priv(expr);
+	struct nft_object_ref *priv = nft_expr_priv(expr);
 
-	obj->ops->eval(obj, regs, pkt);
+	priv->obj->ops->eval(priv->obj, regs, pkt);
 }
 
 static int nft_objref_init(const struct nft_ctx *ctx,
 			   const struct nft_expr *expr,
 			   const struct nlattr * const tb[])
 {
-	struct nft_object *obj = nft_objref_priv(expr);
+	struct nft_object_ref *priv = nft_expr_priv(expr);
 	u8 genmask = nft_genmask_next(ctx->net);
+	struct nft_object *obj;
 	u32 objtype;
 
 	if (!tb[NFTA_OBJREF_IMM_NAME] ||
@@ -41,15 +40,16 @@ static int nft_objref_init(const struct nft_ctx *ctx,
 	if (IS_ERR(obj))
 		return -ENOENT;
 
-	nft_objref_priv(expr) = obj;
 	obj->use++;
+	priv->obj = obj;
 
 	return 0;
 }
 
 static int nft_objref_dump(struct sk_buff *skb, const struct nft_expr *expr)
 {
-	const struct nft_object *obj = nft_objref_priv(expr);
+	const struct nft_object_ref *priv = nft_expr_priv(expr);
+	const struct nft_object *obj = priv->obj;
 
 	if (nla_put_string(skb, NFTA_OBJREF_IMM_NAME, obj->key.name) ||
 	    nla_put_be32(skb, NFTA_OBJREF_TYPE,
@@ -66,7 +66,8 @@ static void nft_objref_deactivate(const struct nft_ctx *ctx,
 				  const struct nft_expr *expr,
 				  enum nft_trans_phase phase)
 {
-	struct nft_object *obj = nft_objref_priv(expr);
+	struct nft_object_ref *priv = nft_expr_priv(expr);
+	struct nft_object *obj = priv->obj;
 
 	if (phase == NFT_TRANS_COMMIT)
 		return;
@@ -77,7 +78,8 @@ static void nft_objref_deactivate(const struct nft_ctx *ctx,
 static void nft_objref_activate(const struct nft_ctx *ctx,
 				const struct nft_expr *expr)
 {
-	struct nft_object *obj = nft_objref_priv(expr);
+	struct nft_object_ref *priv = nft_expr_priv(expr);
+	struct nft_object *obj = priv->obj;
 
 	obj->use++;
 }
@@ -85,7 +87,7 @@ static void nft_objref_activate(const struct nft_ctx *ctx,
 static struct nft_expr_type nft_objref_type;
 static const struct nft_expr_ops nft_objref_ops = {
 	.type		= &nft_objref_type,
-	.size		= NFT_EXPR_SIZE(sizeof(struct nft_object *)),
+	.size		= NFT_EXPR_SIZE(sizeof(struct nft_object_ref)),
 	.eval		= nft_objref_eval,
 	.init		= nft_objref_init,
 	.activate	= nft_objref_activate,
-- 
2.11.0