cfg80211: disallow configuring unsupported interfaces

In order to force drivers to advertise their interface
types, don't just disallow creating new interfaces with
unadvertised types but also disallow setting them UP.
Additionally, add some validation on the operations the
drivers support.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

net/wireless/core.c

@@ -331,8 +331,13 @@ struct wiphy *wiphy_new(const struct cfg80211_ops *ops, int sizeof_priv)
 	struct cfg80211_registered_device *rdev;
 	int alloc_size;
 
-	WARN_ON(!ops->add_key && ops->del_key);
-	WARN_ON(ops->add_key && !ops->del_key);
+	WARN_ON(ops->add_key && (!ops->del_key || !ops->set_default_key));
+	WARN_ON(ops->auth && (!ops->assoc || !ops->deauth || !ops->disassoc));
+	WARN_ON(ops->connect && !ops->disconnect);
+	WARN_ON(ops->join_ibss && !ops->leave_ibss);
+	WARN_ON(ops->add_virtual_intf && !ops->del_virtual_intf);
+	WARN_ON(ops->add_station && !ops->del_station);
+	WARN_ON(ops->add_mpath && !ops->del_mpath);
 
 	alloc_size = sizeof(*rdev) + sizeof_priv;
 
@@ -687,6 +692,8 @@ static int cfg80211_netdev_notifier_call(struct notifier_block * nb,
 		mutex_destroy(&wdev->mtx);
 		break;
 	case NETDEV_PRE_UP:
+		if (!(wdev->wiphy->interface_modes & BIT(wdev->iftype)))
+			return notifier_from_errno(-EOPNOTSUPP);
 		if (rfkill_blocked(rdev->rfkill))
 			return notifier_from_errno(-ERFKILL);
 		break;