core.c

		INIT_LIST_HEAD(&wdev->event_list);
		spin_lock_init(&wdev->event_lock);
		INIT_LIST_HEAD(&wdev->mgmt_registrations);
		spin_lock_init(&wdev->mgmt_registrations_lock);

		wdev->identifier = ++rdev->wdev_id;
		list_add_rcu(&wdev->list, &rdev->wdev_list);
		rdev->devlist_generation++;
		/* can only change netns with wiphy */
		dev->features |= NETIF_F_NETNS_LOCAL;

		if (sysfs_create_link(&dev->dev.kobj, &rdev->wiphy.dev.kobj,
				      "phy80211")) {
			pr_err("failed to add phy80211 symlink to netdev!\n");
		}
		wdev->netdev = dev;
#ifdef CONFIG_CFG80211_WEXT
		wdev->wext.default_key = -1;
		wdev->wext.default_mgmt_key = -1;
		wdev->wext.connect.auth_type = NL80211_AUTHTYPE_AUTOMATIC;
#endif

		if (wdev->wiphy->flags & WIPHY_FLAG_PS_ON_BY_DEFAULT)
			wdev->ps = true;
		else
			wdev->ps = false;
		/* allow mac80211 to determine the timeout */
		wdev->ps_timeout = -1;

		if ((wdev->iftype == NL80211_IFTYPE_STATION ||
		     wdev->iftype == NL80211_IFTYPE_P2P_CLIENT ||
		     wdev->iftype == NL80211_IFTYPE_ADHOC) && !wdev->use_4addr)
			dev->priv_flags |= IFF_DONT_BRIDGE;
		break;
	case NETDEV_GOING_DOWN:
		cfg80211_leave(rdev, wdev);
		break;
	case NETDEV_DOWN:
		cfg80211_update_iface_num(rdev, wdev->iftype, -1);
		if (rdev->scan_req && rdev->scan_req->wdev == wdev) {
			if (WARN_ON(!rdev->scan_req->notified))
				rdev->scan_req->aborted = true;
			___cfg80211_scan_done(rdev, false);
		}

		sched_scan_req = rtnl_dereference(rdev->sched_scan_req);
		if (WARN_ON(sched_scan_req &&
			    sched_scan_req->dev == wdev->netdev)) {
			__cfg80211_stop_sched_scan(rdev, false);
		}

		rdev->opencount--;
		wake_up(&rdev->dev_wait);
		break;
	case NETDEV_UP:
		cfg80211_update_iface_num(rdev, wdev->iftype, 1);
		wdev_lock(wdev);
		switch (wdev->iftype) {
#ifdef CONFIG_CFG80211_WEXT
		case NL80211_IFTYPE_ADHOC:
			cfg80211_ibss_wext_join(rdev, wdev);
			break;
		case NL80211_IFTYPE_STATION:
			cfg80211_mgd_wext_connect(rdev, wdev);
			break;
#endif
#ifdef CONFIG_MAC80211_MESH
		case NL80211_IFTYPE_MESH_POINT:
			{
				/* backward compat code... */
				struct mesh_setup setup;
				memcpy(&setup, &default_mesh_setup,
						sizeof(setup));
				 /* back compat only needed for mesh_id */
				setup.mesh_id = wdev->ssid;
				setup.mesh_id_len = wdev->mesh_id_up_len;
				if (wdev->mesh_id_up_len)
					__cfg80211_join_mesh(rdev, dev,
							&setup,
							&default_mesh_config);
				break;
			}
#endif
		default:
			break;
		}
		wdev_unlock(wdev);
		rdev->opencount++;

		/*
		 * Configure power management to the driver here so that its
		 * correctly set also after interface type changes etc.
		 */
		if ((wdev->iftype == NL80211_IFTYPE_STATION ||
		     wdev->iftype == NL80211_IFTYPE_P2P_CLIENT) &&
		    rdev->ops->set_power_mgmt)
			if (rdev_set_power_mgmt(rdev, dev, wdev->ps,
						wdev->ps_timeout)) {
				/* assume this means it's off */
				wdev->ps = false;
			}
		break;
	case NETDEV_UNREGISTER:
		/*
		 * It is possible to get NETDEV_UNREGISTER
		 * multiple times. To detect that, check
		 * that the interface is still on the list
		 * of registered interfaces, and only then
		 * remove and clean it up.
		 */
		if (!list_empty(&wdev->list)) {
			sysfs_remove_link(&dev->dev.kobj, "phy80211");
			list_del_rcu(&wdev->list);
			rdev->devlist_generation++;
			cfg80211_mlme_purge_registrations(wdev);
#ifdef CONFIG_CFG80211_WEXT
			kzfree(wdev->wext.keys);
#endif
		}
		/*
		 * synchronise (so that we won't find this netdev
		 * from other code any more) and then clear the list
		 * head so that the above code can safely check for
		 * !list_empty() to avoid double-cleanup.
		 */
		synchronize_rcu();
		INIT_LIST_HEAD(&wdev->list);
		/*
		 * Ensure that all events have been processed and
		 * freed.
		 */
		cfg80211_process_wdev_events(wdev);

		if (WARN_ON(wdev->current_bss)) {
			cfg80211_unhold_bss(wdev->current_bss);
			cfg80211_put_bss(wdev->wiphy, &wdev->current_bss->pub);
			wdev->current_bss = NULL;
		}
		break;
	case NETDEV_PRE_UP:
		if (!(wdev->wiphy->interface_modes & BIT(wdev->iftype)))
			return notifier_from_errno(-EOPNOTSUPP);
		if (rfkill_blocked(rdev->rfkill))
			return notifier_from_errno(-ERFKILL);
		break;
	default:
		return NOTIFY_DONE;
	}

	return NOTIFY_OK;
}

static struct notifier_block cfg80211_netdev_notifier = {
	.notifier_call = cfg80211_netdev_notifier_call,
};

static void __net_exit cfg80211_pernet_exit(struct net *net)
{
	struct cfg80211_registered_device *rdev;

	rtnl_lock();
	list_for_each_entry(rdev, &cfg80211_rdev_list, list) {
		if (net_eq(wiphy_net(&rdev->wiphy), net))
			WARN_ON(cfg80211_switch_netns(rdev, &init_net));
	}
	rtnl_unlock();
}

static struct pernet_operations cfg80211_pernet_ops = {
	.exit = cfg80211_pernet_exit,
};

static int __init cfg80211_init(void)
{
	int err;

	err = register_pernet_device(&cfg80211_pernet_ops);
	if (err)
		goto out_fail_pernet;

	err = wiphy_sysfs_init();
	if (err)
		goto out_fail_sysfs;

	err = register_netdevice_notifier(&cfg80211_netdev_notifier);
	if (err)
		goto out_fail_notifier;

	err = nl80211_init();
	if (err)
		goto out_fail_nl80211;

	ieee80211_debugfs_dir = debugfs_create_dir("ieee80211", NULL);

	err = regulatory_init();
	if (err)
		goto out_fail_reg;

	cfg80211_wq = create_singlethread_workqueue("cfg80211");
	if (!cfg80211_wq) {
		err = -ENOMEM;
		goto out_fail_wq;
	}

	return 0;

out_fail_wq:
	regulatory_exit();
out_fail_reg:
	debugfs_remove(ieee80211_debugfs_dir);
	nl80211_exit();
out_fail_nl80211:
	unregister_netdevice_notifier(&cfg80211_netdev_notifier);
out_fail_notifier:
	wiphy_sysfs_exit();
out_fail_sysfs:
	unregister_pernet_device(&cfg80211_pernet_ops);
out_fail_pernet:
	return err;
}
subsys_initcall(cfg80211_init);

static void __exit cfg80211_exit(void)
{
	debugfs_remove(ieee80211_debugfs_dir);
	nl80211_exit();
	unregister_netdevice_notifier(&cfg80211_netdev_notifier);
	wiphy_sysfs_exit();
	regulatory_exit();
	unregister_pernet_device(&cfg80211_pernet_ops);
	destroy_workqueue(cfg80211_wq);
}
module_exit(cfg80211_exit);