nl80211: check channel switch validity better

Before allowing userspace to initiate a channel switch, check
that it's actually connected in some sense. Also use a more
appropriate error code for the not connected case.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index a3515eb..d0f69f5 100644 (file)
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -5771,10 +5771,15 @@ static int nl80211_channel_switch(struct sk_buff *skb, struct genl_info *info)
 
                /* useless if AP is not running */
                if (!wdev->beacon_interval)
-                       return -EINVAL;
+                       return -ENOTCONN;
                break;
        case NL80211_IFTYPE_ADHOC:
+               if (!wdev->ssid_len)
+                       return -ENOTCONN;
+               break;
        case NL80211_IFTYPE_MESH_POINT:
+               if (!wdev->mesh_id_len)
+                       return -ENOTCONN;
                break;
        default:
                return -EOPNOTSUPP;