netfilter: xtables: restrict several matches to inet family

This is a partial revert of:

  commit ab4f21e ("netfilter: xtables: use NFPROTO_UNSPEC in more extensions")

to allow ipv4 and ipv6 only.

- xt_mac
- xt_owner
- xt_physdev

These extensions are not used by ebtables in userspace.

Moreover, xt_realm is only for ipv4, since dst->tclassid is ipv4
specific.

Fixes: ab4f21e ("netfilter: xtables: use NFPROTO_UNSPEC in more extensions")
Reported-by: "Kito Xu (veritas501)" <hxzene@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Author: ummakynes

net/netfilter/xt_mac.c

@@ -36,25 +36,37 @@ static bool mac_mt(const struct sk_buff *skb, struct xt_action_param *par)
 	return ret;
 }
 
-static struct xt_match mac_mt_reg __read_mostly = {
-	.name      = "mac",
-	.revision  = 0,
-	.family    = NFPROTO_UNSPEC,
-	.match     = mac_mt,
-	.matchsize = sizeof(struct xt_mac_info),
-	.hooks     = (1 << NF_INET_PRE_ROUTING) | (1 << NF_INET_LOCAL_IN) |
-	             (1 << NF_INET_FORWARD),
-	.me        = THIS_MODULE,
+static struct xt_match mac_mt_reg[] __read_mostly = {
+	{
+		.name		= "mac",
+		.family		= NFPROTO_IPV4,
+		.match		= mac_mt,
+		.matchsize	= sizeof(struct xt_mac_info),
+		.hooks		= (1 << NF_INET_PRE_ROUTING) |
+				  (1 << NF_INET_LOCAL_IN) |
+				  (1 << NF_INET_FORWARD),
+		.me		= THIS_MODULE,
+	},
+	{
+		.name		= "mac",
+		.family		= NFPROTO_IPV6,
+		.match		= mac_mt,
+		.matchsize	= sizeof(struct xt_mac_info),
+		.hooks		= (1 << NF_INET_PRE_ROUTING) |
+				  (1 << NF_INET_LOCAL_IN) |
+				  (1 << NF_INET_FORWARD),
+		.me		= THIS_MODULE,
+	},
 };
 
 static int __init mac_mt_init(void)
 {
-	return xt_register_match(&mac_mt_reg);
+	return xt_register_matches(mac_mt_reg, ARRAY_SIZE(mac_mt_reg));
 }
 
 static void __exit mac_mt_exit(void)
 {
-	xt_unregister_match(&mac_mt_reg);
+	xt_unregister_matches(mac_mt_reg, ARRAY_SIZE(mac_mt_reg));
 }
 
 module_init(mac_mt_init);

net/netfilter/xt_owner.c

@@ -127,26 +127,39 @@ owner_mt(const struct sk_buff *skb, struct xt_action_param *par)
 	return true;
 }
 
-static struct xt_match owner_mt_reg __read_mostly = {
-	.name       = "owner",
-	.revision   = 1,
-	.family     = NFPROTO_UNSPEC,
-	.checkentry = owner_check,
-	.match      = owner_mt,
-	.matchsize  = sizeof(struct xt_owner_match_info),
-	.hooks      = (1 << NF_INET_LOCAL_OUT) |
-	              (1 << NF_INET_POST_ROUTING),
-	.me         = THIS_MODULE,
+static struct xt_match owner_mt_reg[] __read_mostly = {
+	{
+		.name       = "owner",
+		.revision   = 1,
+		.family     = NFPROTO_IPV4,
+		.checkentry = owner_check,
+		.match      = owner_mt,
+		.matchsize  = sizeof(struct xt_owner_match_info),
+		.hooks      = (1 << NF_INET_LOCAL_OUT) |
+			      (1 << NF_INET_POST_ROUTING),
+		.me         = THIS_MODULE,
+	},
+	{
+		.name       = "owner",
+		.revision   = 1,
+		.family     = NFPROTO_IPV6,
+		.checkentry = owner_check,
+		.match      = owner_mt,
+		.matchsize  = sizeof(struct xt_owner_match_info),
+		.hooks      = (1 << NF_INET_LOCAL_OUT) |
+			      (1 << NF_INET_POST_ROUTING),
+		.me         = THIS_MODULE,
+	}
 };
 
 static int __init owner_mt_init(void)
 {
-	return xt_register_match(&owner_mt_reg);
+	return xt_register_matches(owner_mt_reg, ARRAY_SIZE(owner_mt_reg));
 }
 
 static void __exit owner_mt_exit(void)
 {
-	xt_unregister_match(&owner_mt_reg);
+	xt_unregister_matches(owner_mt_reg, ARRAY_SIZE(owner_mt_reg));
 }
 
 module_init(owner_mt_init);

net/netfilter/xt_physdev.c

@@ -137,24 +137,33 @@ static int physdev_mt_check(const struct xt_mtchk_param *par)
 	return 0;
 }
 
-static struct xt_match physdev_mt_reg __read_mostly = {
-	.name       = "physdev",
-	.revision   = 0,
-	.family     = NFPROTO_UNSPEC,
-	.checkentry = physdev_mt_check,
-	.match      = physdev_mt,
-	.matchsize  = sizeof(struct xt_physdev_info),
-	.me         = THIS_MODULE,
+static struct xt_match physdev_mt_reg[] __read_mostly = {
+	{
+		.name		= "physdev",
+		.family		= NFPROTO_IPV4,
+		.checkentry	= physdev_mt_check,
+		.match		= physdev_mt,
+		.matchsize	= sizeof(struct xt_physdev_info),
+		.me		= THIS_MODULE,
+	},
+	{
+		.name		= "physdev",
+		.family		= NFPROTO_IPV6,
+		.checkentry	= physdev_mt_check,
+		.match		= physdev_mt,
+		.matchsize	= sizeof(struct xt_physdev_info),
+		.me		= THIS_MODULE,
+	},
 };
 
 static int __init physdev_mt_init(void)
 {
-	return xt_register_match(&physdev_mt_reg);
+	return xt_register_matches(physdev_mt_reg, ARRAY_SIZE(physdev_mt_reg));
 }
 
 static void __exit physdev_mt_exit(void)
 {
-	xt_unregister_match(&physdev_mt_reg);
+	xt_unregister_matches(physdev_mt_reg, ARRAY_SIZE(physdev_mt_reg));
 }
 
 module_init(physdev_mt_init);

net/netfilter/xt_realm.c

@@ -33,7 +33,7 @@ static struct xt_match realm_mt_reg __read_mostly = {
 	.matchsize	= sizeof(struct xt_realm_info),
 	.hooks		= (1 << NF_INET_POST_ROUTING) | (1 << NF_INET_FORWARD) |
 			  (1 << NF_INET_LOCAL_OUT) | (1 << NF_INET_LOCAL_IN),
-	.family		= NFPROTO_UNSPEC,
+	.family		= NFPROTO_IPV4,
 	.me		= THIS_MODULE
 };