netfilter: nf_tables: expression ops overloading

Split the expression ops into two parts and support overloading of
the runtime expression ops based on the requested function through
a ->select_ops() callback.

This can be used to provide optimized implementations, for instance
for loading small aligned amounts of data from the packet or inlining
frequently used operations into the main evaluation loop.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 13 insertions, 7 deletions

diff --git a/net/netfilter/nft_expr_template.c b/net/netfilter/nft_expr_template.c
index 9fc8eb308193..b6eed4d5a096 100644
--- a/net/netfilter/nft_expr_template.c
+++ b/net/netfilter/nft_expr_template.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008 Patrick McHardy <kaber@trash.net>
+ * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
@@ -33,7 +33,7 @@ static const struct nla_policy nft_template_policy[NFTA_TEMPLATE_MAX + 1] = {
 
 static int nft_template_init(const struct nft_ctx *ctx,
 			   const struct nft_expr *expr,
-			   const struct nlattr *tb[])
+			   const struct nlattr * const tb[])
 {
 	struct nft_template *priv = nft_expr_priv(expr);
 
@@ -58,26 +58,32 @@ nla_put_failure:
 	return -1;
 }
 
-static struct nft_expr_ops template_ops __read_mostly = {
-	.name		= "template",
+static struct nft_expr_type nft_template_type;
+static const struct nft_expr_ops nft_template_ops = {
+	.type		= &nft_template_type,
 	.size		= NFT_EXPR_SIZE(sizeof(struct nft_template)),
-	.owner		= THIS_MODULE,
 	.eval		= nft_template_eval,
 	.init		= nft_template_init,
 	.destroy	= nft_template_destroy,
 	.dump		= nft_template_dump,
+};
+
+static struct nft_expr_type nft_template_type __read_mostly = {
+	.name		= "template",
+	.ops		= &nft_template_ops,
 	.policy		= nft_template_policy,
 	.maxattr	= NFTA_TEMPLATE_MAX,
+	.owner		= THIS_MODULE,
 };
 
 static int __init nft_template_module_init(void)
 {
-	return nft_register_expr(&template_ops);
+	return nft_register_expr(&nft_template_type);
 }
 
 static void __exit nft_template_module_exit(void)
 {
-	nft_unregister_expr(&template_ops);
+	nft_unregister_expr(&nft_template_type);
 }
 
 module_init(nft_template_module_init);