+#define MPLS_PERDEV_SYSCTL_OFFSET(field) \
+ (&((struct mpls_dev *)0)->field)
+
+static const struct ctl_table mpls_dev_table[] = {
+ {
+ .procname = "input",
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec,
+ .data = MPLS_PERDEV_SYSCTL_OFFSET(input_enabled),
+ },
+ { }
+};
+
+static int mpls_dev_sysctl_register(struct net_device *dev,
+ struct mpls_dev *mdev)
+{
+ char path[sizeof("net/mpls/conf/") + IFNAMSIZ];
+ struct ctl_table *table;
+ int i;
+
+ table = kmemdup(&mpls_dev_table, sizeof(mpls_dev_table), GFP_KERNEL);
+ if (!table)
+ goto out;
+
+ /* Table data contains only offsets relative to the base of
+ * the mdev at this point, so make them absolute.
+ */
+ for (i = 0; i < ARRAY_SIZE(mpls_dev_table); i++)
+ table[i].data = (char *)mdev + (uintptr_t)table[i].data;
+
+ snprintf(path, sizeof(path), "net/mpls/conf/%s", dev->name);
+
+ mdev->sysctl = register_net_sysctl(dev_net(dev), path, table);
+ if (!mdev->sysctl)
+ goto free;
+
+ return 0;
+
+free:
+ kfree(table);
+out:
+ return -ENOBUFS;
+}
+
+static void mpls_dev_sysctl_unregister(struct mpls_dev *mdev)
+{
+ struct ctl_table *table;
+
+ table = mdev->sysctl->ctl_table_arg;
+ unregister_net_sysctl_table(mdev->sysctl);
+ kfree(table);
+}
+