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, 12 insertions, 6 deletions

diff --git a/net/netfilter/nft_byteorder.c b/net/netfilter/nft_byteorder.c
index 8b0657a..c39ed8d 100644
--- a/net/netfilter/nft_byteorder.c
+++ b/net/netfilter/nft_byteorder.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
@@ -145,23 +145,29 @@ nla_put_failure:
 	return -1;
 }
 
-static struct nft_expr_ops nft_byteorder_ops __read_mostly = {
-	.name		= "byteorder",
+static struct nft_expr_type nft_byteorder_type;
+static const struct nft_expr_ops nft_byteorder_ops = {
+	.type		= &nft_byteorder_type,
 	.size		= NFT_EXPR_SIZE(sizeof(struct nft_byteorder)),
-	.owner		= THIS_MODULE,
 	.eval		= nft_byteorder_eval,
 	.init		= nft_byteorder_init,
 	.dump		= nft_byteorder_dump,
+};
+
+static struct nft_expr_type nft_byteorder_type __read_mostly = {
+	.name		= "byteorder",
+	.ops		= &nft_byteorder_ops,
 	.policy		= nft_byteorder_policy,
 	.maxattr	= NFTA_BYTEORDER_MAX,
+	.owner		= THIS_MODULE,
 };
 
 int __init nft_byteorder_module_init(void)
 {
-	return nft_register_expr(&nft_byteorder_ops);
+	return nft_register_expr(&nft_byteorder_type);
 }
 
 void nft_byteorder_module_exit(void)
 {
-	nft_unregister_expr(&nft_byteorder_ops);
+	nft_unregister_expr(&nft_byteorder_type);
 }