netfilter: implement NFPROTO_UNSPEC as a wildcard for extensions

When a match or target is looked up using xt_find_{match,target},
Xtables will also search the NFPROTO_UNSPEC module list. This allows
for protocol-independent extensions (like xt_time) to be reused from
other components (e.g. arptables, ebtables).

Extensions that take different codepaths depending on match->family
or target->family of course cannot use NFPROTO_UNSPEC within the
registration structure (e.g. xt_pkttype).

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>

1 files changed, 11 insertions, 22 deletions

diff --git a/net/netfilter/xt_rateest.c b/net/netfilter/xt_rateest.c
index ba1cb5760f48..4dcfd7353dba 100644
--- a/net/netfilter/xt_rateest.c
+++ b/net/netfilter/xt_rateest.c
@@ -137,36 +137,25 @@ static void xt_rateest_mt_destroy(const struct xt_match *match,
 		xt_rateest_put(info->est2);
 }
 
-static struct xt_match xt_rateest_match[] __read_mostly = {
-	{
-		.family		= NFPROTO_IPV4,
-		.name		= "rateest",
-		.match		= xt_rateest_mt,
-		.checkentry	= xt_rateest_mt_checkentry,
-		.destroy	= xt_rateest_mt_destroy,
-		.matchsize	= sizeof(struct xt_rateest_match_info),
-		.me		= THIS_MODULE,
-	},
-	{
-		.family		= NFPROTO_IPV6,
-		.name		= "rateest",
-		.match		= xt_rateest_mt,
-		.checkentry	= xt_rateest_mt_checkentry,
-		.destroy	= xt_rateest_mt_destroy,
-		.matchsize	= sizeof(struct xt_rateest_match_info),
-		.me		= THIS_MODULE,
-	},
+static struct xt_match xt_rateest_mt_reg __read_mostly = {
+	.name       = "rateest",
+	.revision   = 0,
+	.family     = NFPROTO_UNSPEC,
+	.match      = xt_rateest_mt,
+	.checkentry = xt_rateest_mt_checkentry,
+	.destroy    = xt_rateest_mt_destroy,
+	.matchsize  = sizeof(struct xt_rateest_match_info),
+	.me         = THIS_MODULE,
 };
 
 static int __init xt_rateest_mt_init(void)
 {
-	return xt_register_matches(xt_rateest_match,
-				   ARRAY_SIZE(xt_rateest_match));
+	return xt_register_match(&xt_rateest_mt_reg);
 }
 
 static void __exit xt_rateest_mt_fini(void)
 {
-	xt_unregister_matches(xt_rateest_match, ARRAY_SIZE(xt_rateest_match));
+	xt_unregister_match(&xt_rateest_mt_reg);
 }
 
 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");