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>

4 files changed, 110 insertions, 8 deletions

diff --git a/net/wireless/Kconfig b/net/wireless/Kconfig
index 45005497c634..4428dd5e911d 100644
--- a/net/wireless/Kconfig
+++ b/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"
diff --git a/net/wireless/core.c b/net/wireless/core.c
index a5dbea1da476..3b74b88e10a3 100644
--- a/net/wireless/core.c
+++ b/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 = {
diff --git a/net/wireless/core.h b/net/wireless/core.h
index ab512bcd8153..bfa340c7abb5 100644
--- a/net/wireless/core.h
+++ b/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
diff --git a/net/wireless/wext-compat.c b/net/wireless/wext-compat.c
index 9fbfb8536e75..d030c5315672 100644
--- a/net/wireless/wext-compat.c
+++ b/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;