smack: use pernet operations for hook registration

It will allow us to remove the old netfilter hook api in the near future.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

security/smack/smack_netfilter.c

@@ -18,6 +18,7 @@
 #include <linux/netfilter_ipv6.h>
 #include <linux/netdevice.h>
 #include <net/inet_sock.h>
+#include <net/net_namespace.h>
 #include "smack.h"
 
 #if IS_ENABLED(CONFIG_IPV6)
@@ -74,20 +75,29 @@ static struct nf_hook_ops smack_nf_ops[] = {
 #endif	/* IPV6 */
 };
 
-static int __init smack_nf_ip_init(void)
+static int __net_init smack_nf_register(struct net *net)
+{
+	return nf_register_net_hooks(net, smack_nf_ops,
+				     ARRAY_SIZE(smack_nf_ops));
+}
+
+static void __net_exit smack_nf_unregister(struct net *net)
 {
-	int err;
+	nf_unregister_net_hooks(net, smack_nf_ops, ARRAY_SIZE(smack_nf_ops));
+}
 
+static struct pernet_operations smack_net_ops = {
+	.init = smack_nf_register,
+	.exit = smack_nf_unregister,
+};
+
+static int __init smack_nf_ip_init(void)
+{
 	if (smack_enabled == 0)
 		return 0;
 
 	printk(KERN_DEBUG "Smack: Registering netfilter hooks\n");
-
-	err = nf_register_hooks(smack_nf_ops, ARRAY_SIZE(smack_nf_ops));
-	if (err)
-		pr_info("Smack: nf_register_hooks: error %d\n", err);
-
-	return 0;
+	return register_pernet_subsys(&smack_net_ops);
 }
 
 __initcall(smack_nf_ip_init);