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, 13 insertions, 1 deletions

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index f64837788681..d529bd5eab47 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -472,6 +472,16 @@ enum ieee80211_sub_if_data_flags {
         IEEE80211_SDATA_DONT_BRIDGE_PACKETS     = BIT(3),
 };
 
+/**
+ * enum ieee80211_sdata_state_bits - virtual interface state bits
+ * @SDATA_STATE_RUNNING: virtual interface is up & running; this
+ *      mirrors netif_running() but is separate for interface type
+ *      change handling while the interface is up
+ */
+enum ieee80211_sdata_state_bits {
+        SDATA_STATE_RUNNING,
+};
+
 struct ieee80211_sub_if_data {
         struct list_head list;
 
@@ -485,6 +495,8 @@ struct ieee80211_sub_if_data {
 
         unsigned int flags;
 
+        unsigned long state;
+
         int drop_unencrypted;
 
         char name[IFNAMSIZ];
@@ -1087,7 +1099,7 @@ void ieee80211_recalc_idle(struct ieee80211_local *local);
 
 static inline bool ieee80211_sdata_running(struct ieee80211_sub_if_data *sdata)
 {
-        return netif_running(sdata->dev);
+        return test_bit(SDATA_STATE_RUNNING, &sdata->state);
 }
 
 /* tx handling */