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, 9 insertions, 17 deletions

diff --git a/net/netfilter/xt_TRACE.c b/net/netfilter/xt_TRACE.c
index e1bcad57914e..da35f9f1cd7b 100644
--- a/net/netfilter/xt_TRACE.c
+++ b/net/netfilter/xt_TRACE.c
@@ -19,31 +19,23 @@ trace_tg(struct sk_buff *skb, const struct net_device *in,
 	return XT_CONTINUE;
 }
 
-static struct xt_target trace_tg_reg[] __read_mostly = {
-	{
-		.name		= "TRACE",
-		.family		= NFPROTO_IPV4,
-		.target		= trace_tg,
-		.table		= "raw",
-		.me		= THIS_MODULE,
-	},
-	{
-		.name		= "TRACE",
-		.family		= NFPROTO_IPV6,
-		.target		= trace_tg,
-		.table		= "raw",
-		.me		= THIS_MODULE,
-	},
+static struct xt_target trace_tg_reg __read_mostly = {
+	.name       = "TRACE",
+	.revision   = 0,
+	.family     = NFPROTO_UNSPEC,
+	.table      = "raw",
+	.target     = trace_tg,
+	.me         = THIS_MODULE,
 };
 
 static int __init trace_tg_init(void)
 {
-	return xt_register_targets(trace_tg_reg, ARRAY_SIZE(trace_tg_reg));
+	return xt_register_target(&trace_tg_reg);
 }
 
 static void __exit trace_tg_exit(void)
 {
-	xt_unregister_targets(trace_tg_reg, ARRAY_SIZE(trace_tg_reg));
+	xt_unregister_target(&trace_tg_reg);
 }
 
 module_init(trace_tg_init);