cfg80211: add wdev to testmode cmd

To allow drivers to implement per-interface testmode operations
more easily, pass a wdev pointer if any identification for one
was given from userspace. Clean up the code a bit while at it.

Signed-off-by: David Spinadel <david.spinadel@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index c2a40a2..334697d 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -6591,19 +6591,30 @@
 static int nl80211_testmode_do(struct sk_buff *skb, struct genl_info *info)
 {
 	struct cfg80211_registered_device *rdev = info->user_ptr[0];
+	struct wireless_dev *wdev =
+		__cfg80211_wdev_from_attrs(genl_info_net(info), info->attrs);
 	int err;
 
+	if (!rdev->ops->testmode_cmd)
+		return -EOPNOTSUPP;
+
+	if (IS_ERR(wdev)) {
+		err = PTR_ERR(wdev);
+		if (err != -EINVAL)
+			return err;
+		wdev = NULL;
+	} else if (wdev->wiphy != &rdev->wiphy) {
+		return -EINVAL;
+	}
+
 	if (!info->attrs[NL80211_ATTR_TESTDATA])
 		return -EINVAL;
 
-	err = -EOPNOTSUPP;
-	if (rdev->ops->testmode_cmd) {
-		rdev->testmode_info = info;
-		err = rdev_testmode_cmd(rdev,
+	rdev->testmode_info = info;
+	err = rdev_testmode_cmd(rdev, wdev,
 				nla_data(info->attrs[NL80211_ATTR_TESTDATA]),
 				nla_len(info->attrs[NL80211_ATTR_TESTDATA]));
-		rdev->testmode_info = NULL;
-	}
+	rdev->testmode_info = NULL;
 
 	return err;
 }