cfg80211: validate scan channels

Currently it is possible to request a scan on only
disabled channels, which could be problematic for
some drivers. Reject such scans, and also ignore
disabled channels that are given. This resuls in
the scan begin/end event only including channels
that are actually used.

This makes the mac80211 check for disabled channels
superfluous. At the same time, remove the no-IBSS
check from mac80211 -- nothing says that we should
not find any networks on channels that cannot be
used for an IBSS, even when operating in IBSS mode.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 2 insertions, 11 deletions

diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c
index 88a9a1be314a..4cf387c944bf 100644
--- a/net/mac80211/scan.c
+++ b/net/mac80211/scan.c
@@ -614,23 +614,14 @@ static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
 {
         int skip;
         struct ieee80211_channel *chan;
-        struct ieee80211_sub_if_data *sdata = local->scan_sdata;
 
         skip = 0;
         chan = local->scan_req->channels[local->scan_channel_idx];
 
-        if (chan->flags & IEEE80211_CHAN_DISABLED ||
-            (sdata->vif.type == NL80211_IFTYPE_ADHOC &&
-             chan->flags & IEEE80211_CHAN_NO_IBSS))
+        local->scan_channel = chan;
+        if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
                 skip = 1;
 
-        if (!skip) {
-                local->scan_channel = chan;
-                if (ieee80211_hw_config(local,
-                                        IEEE80211_CONF_CHANGE_CHANNEL))
-                        skip = 1;
-        }
-
         /* advance state machine to next channel/band */
         local->scan_channel_idx++;