netdev - [PATCH net-next 09/14] netfilter: nft_compat: suppress comment match

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Message-Id: <20220209133616.165104-10-pablo@netfilter.org>
Date:   Wed,  9 Feb 2022 14:36:11 +0100
From:   Pablo Neira Ayuso <pablo@...filter.org>
To:     netfilter-devel@...r.kernel.org
Cc:     davem@...emloft.net, netdev@...r.kernel.org, kuba@...nel.org
Subject: [PATCH net-next 09/14] netfilter: nft_compat: suppress comment match

From: Florian Westphal <fw@...len.de>

No need to have the datapath call the always-true comment match stub.

Signed-off-by: Florian Westphal <fw@...len.de>
Signed-off-by: Pablo Neira Ayuso <pablo@...filter.org>
---
 net/netfilter/nft_compat.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/net/netfilter/nft_compat.c b/net/netfilter/nft_compat.c
index f69cc73c5813..5a46d8289d1d 100644
--- a/net/netfilter/nft_compat.c
+++ b/net/netfilter/nft_compat.c
@@ -731,6 +731,14 @@ static const struct nfnetlink_subsystem nfnl_compat_subsys = {
 
 static struct nft_expr_type nft_match_type;
 
+static bool nft_match_reduce(struct nft_regs_track *track,
+			     const struct nft_expr *expr)
+{
+	const struct xt_match *match = expr->ops->data;
+
+	return strcmp(match->name, "comment") == 0;
+}
+
 static const struct nft_expr_ops *
 nft_match_select_ops(const struct nft_ctx *ctx,
 		     const struct nlattr * const tb[])
@@ -773,6 +781,7 @@ nft_match_select_ops(const struct nft_ctx *ctx,
 	ops->dump = nft_match_dump;
 	ops->validate = nft_match_validate;
 	ops->data = match;
+	ops->reduce = nft_match_reduce;
 
 	matchsize = NFT_EXPR_SIZE(XT_ALIGN(match->matchsize));
 	if (matchsize > NFT_MATCH_LARGE_THRESH) {
-- 
2.30.2