netfilter: nf_nat_masquerade: unify ipv4/6 notifier registration

Only reason for having two different register functions was because of
ipt_MASQUERADE and ip6t_MASQUERADE being two different modules.

Previous patch merged those into xt_MASQUERADE, so we can merge this too.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 37 insertions, 64 deletions

diff --git a/net/netfilter/nf_nat_masquerade.c b/net/netfilter/nf_nat_masquerade.c
index 10053e70f69d..8e8a65d46345 100644
--- a/net/netfilter/nf_nat_masquerade.c
+++ b/net/netfilter/nf_nat_masquerade.c
@@ -10,8 +10,7 @@
 #include <net/netfilter/nf_nat_masquerade.h>
 
 static DEFINE_MUTEX(masq_mutex);
-static unsigned int masq_refcnt4 __read_mostly;
-static unsigned int masq_refcnt6 __read_mostly;
+static unsigned int masq_refcnt __read_mostly;
 
 unsigned int
 nf_nat_masquerade_ipv4(struct sk_buff *skb, unsigned int hooknum,
@@ -136,56 +135,6 @@ static struct notifier_block masq_inet_notifier = {
 	.notifier_call	= masq_inet_event,
 };
 
-int nf_nat_masquerade_ipv4_register_notifier(void)
-{
-	int ret = 0;
-
-	mutex_lock(&masq_mutex);
-	if (WARN_ON_ONCE(masq_refcnt4 == UINT_MAX)) {
-		ret = -EOVERFLOW;
-		goto out_unlock;
-	}
-
-	/* check if the notifier was already set */
-	if (++masq_refcnt4 > 1)
-		goto out_unlock;
-
-	/* Register for device down reports */
-	ret = register_netdevice_notifier(&masq_dev_notifier);
-	if (ret)
-		goto err_dec;
-	/* Register IP address change reports */
-	ret = register_inetaddr_notifier(&masq_inet_notifier);
-	if (ret)
-		goto err_unregister;
-
-	mutex_unlock(&masq_mutex);
-	return ret;
-
-err_unregister:
-	unregister_netdevice_notifier(&masq_dev_notifier);
-err_dec:
-	masq_refcnt4--;
-out_unlock:
-	mutex_unlock(&masq_mutex);
-	return ret;
-}
-EXPORT_SYMBOL_GPL(nf_nat_masquerade_ipv4_register_notifier);
-
-void nf_nat_masquerade_ipv4_unregister_notifier(void)
-{
-	mutex_lock(&masq_mutex);
-	/* check if the notifier still has clients */
-	if (--masq_refcnt4 > 0)
-		goto out_unlock;
-
-	unregister_netdevice_notifier(&masq_dev_notifier);
-	unregister_inetaddr_notifier(&masq_inet_notifier);
-out_unlock:
-	mutex_unlock(&masq_mutex);
-}
-EXPORT_SYMBOL_GPL(nf_nat_masquerade_ipv4_unregister_notifier);
-
 #if IS_ENABLED(CONFIG_IPV6)
 static atomic_t v6_worker_count __read_mostly;
 
@@ -321,44 +270,68 @@ static struct notifier_block masq_inet6_notifier = {
 	.notifier_call	= masq_inet6_event,
 };
 
-int nf_nat_masquerade_ipv6_register_notifier(void)
+static int nf_nat_masquerade_ipv6_register_notifier(void)
+{
+	return register_inet6addr_notifier(&masq_inet6_notifier);
+}
+#else
+static inline int nf_nat_masquerade_ipv6_register_notifier(void) { return 0; }
+#endif
+
+int nf_nat_masquerade_inet_register_notifiers(void)
 {
 	int ret = 0;
 
 	mutex_lock(&masq_mutex);
-	if (WARN_ON_ONCE(masq_refcnt6 == UINT_MAX)) {
+	if (WARN_ON_ONCE(masq_refcnt == UINT_MAX)) {
 		ret = -EOVERFLOW;
 		goto out_unlock;
 	}
 
-	/* check if the notifier is already set */
-	if (++masq_refcnt6 > 1)
+	/* check if the notifier was already set */
+	if (++masq_refcnt > 1)
 		goto out_unlock;
 
-	ret = register_inet6addr_notifier(&masq_inet6_notifier);
+	/* Register for device down reports */
+	ret = register_netdevice_notifier(&masq_dev_notifier);
 	if (ret)
 		goto err_dec;
+	/* Register IP address change reports */
+	ret = register_inetaddr_notifier(&masq_inet_notifier);
+	if (ret)
+		goto err_unregister;
+
+	ret = nf_nat_masquerade_ipv6_register_notifier();
+	if (ret)
+		goto err_unreg_inet;
 
 	mutex_unlock(&masq_mutex);
 	return ret;
+err_unreg_inet:
+	unregister_inetaddr_notifier(&masq_inet_notifier);
+err_unregister:
+	unregister_netdevice_notifier(&masq_dev_notifier);
 err_dec:
-	masq_refcnt6--;
+	masq_refcnt--;
 out_unlock:
 	mutex_unlock(&masq_mutex);
 	return ret;
 }
-EXPORT_SYMBOL_GPL(nf_nat_masquerade_ipv6_register_notifier);
+EXPORT_SYMBOL_GPL(nf_nat_masquerade_inet_register_notifiers);
 
-void nf_nat_masquerade_ipv6_unregister_notifier(void)
+void nf_nat_masquerade_inet_unregister_notifiers(void)
 {
 	mutex_lock(&masq_mutex);
-	/* check if the notifier still has clients */
-	if (--masq_refcnt6 > 0)
+	/* check if the notifiers still have clients */
+	if (--masq_refcnt > 0)
 		goto out_unlock;
 
+	unregister_netdevice_notifier(&masq_dev_notifier);
+	unregister_inetaddr_notifier(&masq_inet_notifier);
+#if IS_ENABLED(CONFIG_IPV6)
 	unregister_inet6addr_notifier(&masq_inet6_notifier);
+#endif
 out_unlock:
 	mutex_unlock(&masq_mutex);
 }
-EXPORT_SYMBOL_GPL(nf_nat_masquerade_ipv6_unregister_notifier);
-#endif
+EXPORT_SYMBOL_GPL(nf_nat_masquerade_inet_unregister_notifiers);