mac80211: allow driver to prevent two stations w/ same address
Some devices or drivers cannot deal with having the same station
address for different virtual interfaces, say as a client to two
virtual AP interfaces. Rather than requiring each driver with a
limitation like that to enforce it, add a hardware flag for it.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index f91d187..8f630f5 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -435,6 +435,19 @@
is_multicast_ether_addr(sta->sta.addr)))
return -EINVAL;
+ /* Strictly speaking this isn't necessary as we hold the mutex, but
+ * the rhashtable code can't really deal with that distinction. We
+ * do require the mutex for correctness though.
+ */
+ rcu_read_lock();
+ lockdep_assert_held(&sdata->local->sta_mtx);
+ if (ieee80211_hw_check(&sdata->local->hw, NEEDS_UNIQUE_STA_ADDR) &&
+ ieee80211_find_sta_by_ifaddr(&sdata->local->hw, sta->addr, NULL)) {
+ rcu_read_unlock();
+ return -ENOTUNIQ;
+ }
+ rcu_read_unlock();
+
return 0;
}
@@ -554,14 +567,15 @@
might_sleep();
+ mutex_lock(&local->sta_mtx);
+
err = sta_info_insert_check(sta);
if (err) {
+ mutex_unlock(&local->sta_mtx);
rcu_read_lock();
goto out_free;
}
- mutex_lock(&local->sta_mtx);
-
err = sta_info_insert_finish(sta);
if (err)
goto out_free;