cfg80211: add rfkill support

To be easier on drivers and users, have cfg80211 register an
rfkill structure that drivers can access. When soft-killed,
simply take down all interfaces; when hard-killed the driver
needs to notify us and we will take down the interfaces
after the fact. While rfkilled, interfaces cannot be set UP.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

net/wireless/Kconfig

@@ -1,5 +1,6 @@
 config CFG80211
-        tristate "Improved wireless configuration API"
+	tristate "Improved wireless configuration API"
+	depends on RFKILL || !RFKILL
 
 config CFG80211_REG_DEBUG
 	bool "cfg80211 regulatory debugging"

net/wireless/core.c

@@ -12,6 +12,7 @@
 #include <linux/debugfs.h>
 #include <linux/notifier.h>
 #include <linux/device.h>
+#include <linux/rtnetlink.h>
 #include <net/genetlink.h>
 #include <net/cfg80211.h>
 #include "nl80211.h"
@@ -227,6 +228,41 @@ int cfg80211_dev_rename(struct cfg80211_registered_device *rdev,
 	return 0;
 }
 
+static void cfg80211_rfkill_poll(struct rfkill *rfkill, void *data)
+{
+	struct cfg80211_registered_device *drv = data;
+
+	drv->ops->rfkill_poll(&drv->wiphy);
+}
+
+static int cfg80211_rfkill_set_block(void *data, bool blocked)
+{
+	struct cfg80211_registered_device *drv = data;
+	struct wireless_dev *wdev;
+
+	if (!blocked)
+		return 0;
+
+	rtnl_lock();
+	mutex_lock(&drv->devlist_mtx);
+
+	list_for_each_entry(wdev, &drv->netdev_list, list)
+		dev_close(wdev->netdev);
+
+	mutex_unlock(&drv->devlist_mtx);
+	rtnl_unlock();
+
+	return 0;
+}
+
+static void cfg80211_rfkill_sync_work(struct work_struct *work)
+{
+	struct cfg80211_registered_device *drv;
+
+	drv = container_of(work, struct cfg80211_registered_device, rfkill_sync);
+	cfg80211_rfkill_set_block(drv, rfkill_blocked(drv->rfkill));
+}
+
 /* exported functions */
 
 struct wiphy *wiphy_new(const struct cfg80211_ops *ops, int sizeof_priv)
@@ -274,6 +310,18 @@ struct wiphy *wiphy_new(const struct cfg80211_ops *ops, int sizeof_priv)
 	drv->wiphy.dev.class = &ieee80211_class;
 	drv->wiphy.dev.platform_data = drv;
 
+	drv->rfkill_ops.set_block = cfg80211_rfkill_set_block;
+	drv->rfkill = rfkill_alloc(dev_name(&drv->wiphy.dev),
+				   &drv->wiphy.dev, RFKILL_TYPE_WLAN,
+				   &drv->rfkill_ops, drv);
+
+	if (!drv->rfkill) {
+		kfree(drv);
+		return NULL;
+	}
+
+	INIT_WORK(&drv->rfkill_sync, cfg80211_rfkill_sync_work);
+
 	/*
 	 * Initialize wiphy parameters to IEEE 802.11 MIB default values.
 	 * Fragmentation and RTS threshold are disabled by default with the
@@ -356,6 +404,10 @@ int wiphy_register(struct wiphy *wiphy)
 	if (res)
 		goto out_unlock;
 
+	res = rfkill_register(drv->rfkill);
+	if (res)
+		goto out_rm_dev;
+
 	list_add(&drv->list, &cfg80211_drv_list);
 
 	/* add to debugfs */
@@ -379,16 +431,41 @@ int wiphy_register(struct wiphy *wiphy)
 	cfg80211_debugfs_drv_add(drv);
 
 	res = 0;
-out_unlock:
+	goto out_unlock;
+
+ out_rm_dev:
+	device_del(&drv->wiphy.dev);
+ out_unlock:
 	mutex_unlock(&cfg80211_mutex);
 	return res;
 }
 EXPORT_SYMBOL(wiphy_register);
 
+void wiphy_rfkill_start_polling(struct wiphy *wiphy)
+{
+	struct cfg80211_registered_device *drv = wiphy_to_dev(wiphy);
+
+	if (!drv->ops->rfkill_poll)
+		return;
+	drv->rfkill_ops.poll = cfg80211_rfkill_poll;
+	rfkill_resume_polling(drv->rfkill);
+}
+EXPORT_SYMBOL(wiphy_rfkill_start_polling);
+
+void wiphy_rfkill_stop_polling(struct wiphy *wiphy)
+{
+	struct cfg80211_registered_device *drv = wiphy_to_dev(wiphy);
+
+	rfkill_pause_polling(drv->rfkill);
+}
+EXPORT_SYMBOL(wiphy_rfkill_stop_polling);
+
 void wiphy_unregister(struct wiphy *wiphy)
 {
 	struct cfg80211_registered_device *drv = wiphy_to_dev(wiphy);
 
+	rfkill_unregister(drv->rfkill);
+
 	/* protect the device list */
 	mutex_lock(&cfg80211_mutex);
 
@@ -425,6 +502,7 @@ EXPORT_SYMBOL(wiphy_unregister);
 void cfg80211_dev_free(struct cfg80211_registered_device *drv)
 {
 	struct cfg80211_internal_bss *scan, *tmp;
+	rfkill_destroy(drv->rfkill);
 	mutex_destroy(&drv->mtx);
 	mutex_destroy(&drv->devlist_mtx);
 	list_for_each_entry_safe(scan, tmp, &drv->bss_list, list)
@@ -438,6 +516,15 @@ void wiphy_free(struct wiphy *wiphy)
 }
 EXPORT_SYMBOL(wiphy_free);
 
+void wiphy_rfkill_set_hw_state(struct wiphy *wiphy, bool blocked)
+{
+	struct cfg80211_registered_device *drv = wiphy_to_dev(wiphy);
+
+	if (rfkill_set_hw_state(drv->rfkill, blocked))
+		schedule_work(&drv->rfkill_sync);
+}
+EXPORT_SYMBOL(wiphy_rfkill_set_hw_state);
+
 static int cfg80211_netdev_notifier_call(struct notifier_block * nb,
 					 unsigned long state,
 					 void *ndev)
@@ -446,7 +533,7 @@ static int cfg80211_netdev_notifier_call(struct notifier_block * nb,
 	struct cfg80211_registered_device *rdev;
 
 	if (!dev->ieee80211_ptr)
-		return 0;
+		return NOTIFY_DONE;
 
 	rdev = wiphy_to_dev(dev->ieee80211_ptr->wiphy);
 
@@ -492,9 +579,13 @@ static int cfg80211_netdev_notifier_call(struct notifier_block * nb,
 		}
 		mutex_unlock(&rdev->devlist_mtx);
 		break;
+	case NETDEV_PRE_UP:
+		if (rfkill_blocked(rdev->rfkill))
+			return notifier_from_errno(-ERFKILL);
+		break;
 	}
 
-	return 0;
+	return NOTIFY_DONE;
 }
 
 static struct notifier_block cfg80211_netdev_notifier = {

net/wireless/core.h

@@ -11,6 +11,8 @@
 #include <linux/kref.h>
 #include <linux/rbtree.h>
 #include <linux/debugfs.h>
+#include <linux/rfkill.h>
+#include <linux/workqueue.h>
 #include <net/genetlink.h>
 #include <net/cfg80211.h>
 #include "reg.h"
@@ -24,6 +26,11 @@ struct cfg80211_registered_device {
 	 * any call is in progress */
 	struct mutex mtx;
 
+	/* rfkill support */
+	struct rfkill_ops rfkill_ops;
+	struct rfkill *rfkill;
+	struct work_struct rfkill_sync;
+
 	/* ISO / IEC 3166 alpha2 for which this device is receiving
 	 * country IEs on, this can help disregard country IEs from APs
 	 * on the same alpha2 quickly. The alpha2 may differ from

net/wireless/wext-compat.c

@@ -764,6 +764,8 @@ int cfg80211_wext_siwtxpower(struct net_device *dev,
 
 	/* only change when not disabling */
 	if (!data->txpower.disabled) {
+		rfkill_set_sw_state(rdev->rfkill, false);
+
 		if (data->txpower.fixed) {
 			/*
 			 * wext doesn't support negative values, see
@@ -787,7 +789,9 @@ int cfg80211_wext_siwtxpower(struct net_device *dev,
 			}
 		}
 	} else {
-		type = TX_POWER_OFF;
+		rfkill_set_sw_state(rdev->rfkill, true);
+		schedule_work(&rdev->rfkill_sync);
+		return 0;
 	}
 
 	return rdev->ops->set_tx_power(wdev->wiphy, type, dbm);;
@@ -811,13 +815,12 @@ int cfg80211_wext_giwtxpower(struct net_device *dev,
 		return -EOPNOTSUPP;
 
 	err = rdev->ops->get_tx_power(wdev->wiphy, &val);
-	/* HACK!!! */
-	if (err && err != -ENETDOWN)
+	if (err)
 		return err;
 
 	/* well... oh well */
 	data->txpower.fixed = 1;
-	data->txpower.disabled = err == -ENETDOWN;
+	data->txpower.disabled = rfkill_blocked(rdev->rfkill);
 	data->txpower.value = val;
 	data->txpower.flags = IW_TXPOW_DBM;