mac80211: add beacon configuration via cfg80211
This patch implements the cfg80211 hooks for configuring beaconing
on an access point interface in mac80211. While doing so, it fixes
a number of races that could badly crash the machine when the
beacon is changed while being requested by the driver.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/ieee80211.c b/net/mac80211/ieee80211.c
index c998170..859682e 100644
--- a/net/mac80211/ieee80211.c
+++ b/net/mac80211/ieee80211.c
@@ -321,10 +321,17 @@
dev_mc_unsync(local->mdev, dev);
- /* down all dependent devices, that is VLANs */
+ /* APs need special treatment */
if (sdata->vif.type == IEEE80211_IF_TYPE_AP) {
struct ieee80211_sub_if_data *vlan, *tmp;
+ struct beacon_data *old_beacon = sdata->u.ap.beacon;
+ /* remove beacon */
+ rcu_assign_pointer(sdata->u.ap.beacon, NULL);
+ synchronize_rcu();
+ kfree(old_beacon);
+
+ /* down all dependent devices, that is VLANs */
list_for_each_entry_safe(vlan, tmp, &sdata->u.ap.vlans,
u.vlan.list)
dev_close(vlan->dev);