This looks very much like the patch for ipv4's devinet.

This is also intended to help us with the net namespaces
and saves the ipv6.ko size by ~320 bytes.

The difference from the first version is just the patch
offsets, that changed due to changes in the patch #2.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>

---

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index ea1673d..dbff389 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -3848,10 +3848,7 @@ static struct addrconf_sysctl_table
 {
 	struct ctl_table_header *sysctl_header;
 	ctl_table addrconf_vars[__NET_IPV6_MAX];
-	ctl_table addrconf_dev[2];
-	ctl_table addrconf_conf_dir[2];
-	ctl_table addrconf_proto_dir[2];
-	ctl_table addrconf_root_dir[2];
+	char *dev_name;
 } addrconf_sysctl __read_mostly = {
 	.sysctl_header = NULL,
 	.addrconf_vars = {
@@ -4072,50 +4069,6 @@ static struct addrconf_sysctl_table
 			.ctl_name	=	0,	/* sentinel */
 		}
 	},
-	.addrconf_dev = {
-		{
-			.ctl_name	=	NET_PROTO_CONF_ALL,
-			.procname	=	"all",
-			.mode		=	0555,
-			.child		=	addrconf_sysctl.addrconf_vars,
-		},
-		{
-			.ctl_name	=	0,	/* sentinel */
-		}
-	},
-	.addrconf_conf_dir = {
-		{
-			.ctl_name	=	NET_IPV6_CONF,
-			.procname	=	"conf",
-			.mode		=	0555,
-			.child		=	addrconf_sysctl.addrconf_dev,
-		},
-		{
-			.ctl_name	=	0,	/* sentinel */
-		}
-	},
-	.addrconf_proto_dir = {
-		{
-			.ctl_name	=	NET_IPV6,
-			.procname	=	"ipv6",
-			.mode		=	0555,
-			.child		=	addrconf_sysctl.addrconf_conf_dir,
-		},
-		{
-			.ctl_name	=	0,	/* sentinel */
-		}
-	},
-	.addrconf_root_dir = {
-		{
-			.ctl_name	=	CTL_NET,
-			.procname	=	"net",
-			.mode		=	0555,
-			.child		=	addrconf_sysctl.addrconf_proto_dir,
-		},
-		{
-			.ctl_name	=	0,	/* sentinel */
-		}
-	},
 };
 
 static void __addrconf_sysctl_register(char *dev_name, int ctl_name,
@@ -4124,6 +4077,17 @@ static void __addrconf_sysctl_register(char *dev_name, int ctl_name,
 	int i;
 	struct addrconf_sysctl_table *t;
 
+#define ADDRCONF_CTL_PATH_DEV	3
+
+	struct ctl_path addrconf_ctl_path[] = {
+		{ .procname = "net", .ctl_name = CTL_NET, },
+		{ .procname = "ipv6", .ctl_name = NET_IPV6, },
+		{ .procname = "conf", .ctl_name = NET_IPV6_CONF, },
+		{ /* to be set */ },
+		{ },
+	};
+
+
 	t = kmemdup(&addrconf_sysctl, sizeof(*t), GFP_KERNEL);
 	if (t == NULL)
 		goto out;
@@ -4138,19 +4102,15 @@ static void __addrconf_sysctl_register(char *dev_name, int ctl_name,
 	 * by sysctl and we wouldn't want anyone to change it under our feet
 	 * (see SIOCSIFNAME).
 	 */
-	dev_name = kstrdup(dev_name, GFP_KERNEL);
-	if (!dev_name)
+	t->dev_name = kstrdup(dev_name, GFP_KERNEL);
+	if (!t->dev_name)
 		goto free;
 
-	t->addrconf_dev[0].ctl_name = ctl_name;
-	t->addrconf_dev[0].procname = dev_name;
-
-	t->addrconf_dev[0].child = t->addrconf_vars;
-	t->addrconf_conf_dir[0].child = t->addrconf_dev;
-	t->addrconf_proto_dir[0].child = t->addrconf_conf_dir;
-	t->addrconf_root_dir[0].child = t->addrconf_proto_dir;
+	addrconf_ctl_path[ADDRCONF_CTL_PATH_DEV].procname = t->dev_name;
+	addrconf_ctl_path[ADDRCONF_CTL_PATH_DEV].ctl_name = ctl_name;
 
-	t->sysctl_header = register_sysctl_table(t->addrconf_root_dir);
+	t->sysctl_header = register_sysctl_paths(addrconf_ctl_path,
+			t->addrconf_vars);
 	if (t->sysctl_header == NULL)
 		goto free_procname;
 
@@ -4158,7 +4118,7 @@ static void __addrconf_sysctl_register(char *dev_name, int ctl_name,
 	return;
 
 free_procname:
-	kfree(dev_name);
+	kfree(t->dev_name);
 free:
 	kfree(t);
 out:
@@ -4177,7 +4137,7 @@ static void addrconf_sysctl_unregister(struct ipv6_devconf *p)
 		struct addrconf_sysctl_table *t = p->sysctl;
 		p->sysctl = NULL;
 		unregister_sysctl_table(t->sysctl_header);
-		kfree(t->addrconf_dev[0].procname);
+		kfree(t->dev_name);
 		kfree(t);
 	}
 }
-- 
1.5.3.4