mac80211: add api to set CSA counter in mac80211

Sometimes the most updated CSA counter values are known only
to the device. Add an API to pass this data to mac80211.

Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index d2279b2d61aa98ca4bee0f338f00dbca13f6b2cf..52f36c43f35fbc587f02d1f1adf0e0c50567be5d 100644 (file)
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -4449,6 +4449,19 @@ static inline struct sk_buff *ieee80211_beacon_get(struct ieee80211_hw *hw,
  */
 u8 ieee80211_csa_update_counter(struct ieee80211_vif *vif);
 
+/**
+ * ieee80211_csa_set_counter - request mac80211 to set csa counter
+ * @vif: &struct ieee80211_vif pointer from the add_interface callback.
+ * @counter: the new value for the counter
+ *
+ * The csa counter can be changed by the device, this API should be
+ * used by the device driver to update csa counter in mac80211.
+ *
+ * It should never be used together with ieee80211_csa_update_counter(),
+ * as it will cause a race condition around the counter value.
+ */
+void ieee80211_csa_set_counter(struct ieee80211_vif *vif, u8 counter);
+
 /**
  * ieee80211_csa_finish - notify mac80211 about channel switch
  * @vif: &struct ieee80211_vif pointer from the add_interface callback.

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 535de3161a781f90ea9a91e97fdc4aa46db0eac6..062e125a324c2cce3850153a00f19ccf6366f990 100644 (file)
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -4084,6 +4084,31 @@ unlock:
 }
 EXPORT_SYMBOL(ieee80211_csa_update_counter);
 
+void ieee80211_csa_set_counter(struct ieee80211_vif *vif, u8 counter)
+{
+       struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
+       struct beacon_data *beacon = NULL;
+
+       rcu_read_lock();
+
+       if (sdata->vif.type == NL80211_IFTYPE_AP)
+               beacon = rcu_dereference(sdata->u.ap.beacon);
+       else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
+               beacon = rcu_dereference(sdata->u.ibss.presp);
+       else if (ieee80211_vif_is_mesh(&sdata->vif))
+               beacon = rcu_dereference(sdata->u.mesh.beacon);
+
+       if (!beacon)
+               goto unlock;
+
+       if (counter < beacon->csa_current_counter)
+               beacon->csa_current_counter = counter;
+
+unlock:
+       rcu_read_unlock();
+}
+EXPORT_SYMBOL(ieee80211_csa_set_counter);
+
 bool ieee80211_csa_is_complete(struct ieee80211_vif *vif)
 {
        struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);