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, 12 insertions, 26 deletions

diff --git a/net/netfilter/xt_CLASSIFY.c b/net/netfilter/xt_CLASSIFY.c
index 9d68da1748b..8cffa295dd3 100644
--- a/net/netfilter/xt_CLASSIFY.c
+++ b/net/netfilter/xt_CLASSIFY.c
@@ -37,40 +37,26 @@ classify_tg(struct sk_buff *skb, const struct net_device *in,
         return XT_CONTINUE;
 }
 
-static struct xt_target classify_tg_reg[] __read_mostly = {
-        {
-                .family         = NFPROTO_IPV4,
-                .name           = "CLASSIFY",
-                .target         = classify_tg,
-                .targetsize     = sizeof(struct xt_classify_target_info),
-                .table          = "mangle",
-                .hooks          = (1 << NF_INET_LOCAL_OUT) |
-                                  (1 << NF_INET_FORWARD) |
-                                  (1 << NF_INET_POST_ROUTING),
-                .me             = THIS_MODULE,
-        },
-        {
-                .name           = "CLASSIFY",
-                .family         = NFPROTO_IPV6,
-                .target         = classify_tg,
-                .targetsize     = sizeof(struct xt_classify_target_info),
-                .table          = "mangle",
-                .hooks          = (1 << NF_INET_LOCAL_OUT) |
-                                  (1 << NF_INET_FORWARD) |
-                                  (1 << NF_INET_POST_ROUTING),
-                .me             = THIS_MODULE,
-        },
+static struct xt_target classify_tg_reg __read_mostly = {
+        .name       = "CLASSIFY",
+        .revision   = 0,
+        .family     = NFPROTO_UNSPEC,
+        .table      = "mangle",
+        .hooks      = (1 << NF_INET_LOCAL_OUT) | (1 << NF_INET_FORWARD) |
+                      (1 << NF_INET_POST_ROUTING),
+        .target     = classify_tg,
+        .targetsize = sizeof(struct xt_classify_target_info),
+        .me         = THIS_MODULE,
 };
 
 static int __init classify_tg_init(void)
 {
-        return xt_register_targets(classify_tg_reg,
-               ARRAY_SIZE(classify_tg_reg));
+        return xt_register_target(&classify_tg_reg);
 }
 
 static void __exit classify_tg_exit(void)
 {
-        xt_unregister_targets(classify_tg_reg, ARRAY_SIZE(classify_tg_reg));
+        xt_unregister_target(&classify_tg_reg);
 }
 
 module_init(classify_tg_init);