mac80211: support runtime interface type changes

Add support to mac80211 for changing the interface
type even when the interface is UP, if the driver
supports it.

To achieve this
 * add a new driver callback for switching,
 * split some of the interface up/down code out
   into new functions (do_open/do_stop), and
 * maintain an own __SDATA_RUNNING bit that will
   not be set during interface type, so that any
   other code doesn't use the interface.

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

1 files changed, 9 insertions, 0 deletions

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 8f97548b6d80..f91fc331369b 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -1537,6 +1537,12 @@ enum ieee80211_ampdu_mlme_action {
  *      negative error code (which will be seen in userspace.)
  *      Must be implemented and can sleep.
  *
+ * @change_interface: Called when a netdevice changes type. This callback
+ *      is optional, but only if it is supported can interface types be
+ *      switched while the interface is UP. The callback may sleep.
+ *      Note that while an interface is being switched, it will not be
+ *      found by the interface iteration callbacks.
+ *
  * @remove_interface: Notifies a driver that an interface is going down.
  *      The @stop callback is called after this if it is the last interface
  *      and no monitor interfaces are present.
@@ -1693,6 +1699,9 @@ struct ieee80211_ops {
         void (*stop)(struct ieee80211_hw *hw);
         int (*add_interface)(struct ieee80211_hw *hw,
                              struct ieee80211_vif *vif);
+        int (*change_interface)(struct ieee80211_hw *hw,
+                                struct ieee80211_vif *vif,
+                                enum nl80211_iftype new_type);
         void (*remove_interface)(struct ieee80211_hw *hw,
                                  struct ieee80211_vif *vif);
         int (*config)(struct ieee80211_hw *hw, u32 changed);