mac80211: add TDLS supported channels correctly

The function adding the supported channels IE during a TDLS connection had
several issues:
1. If the entire subband is usable, the function exitted the loop without
   adding it
2. The function only checked chandef_usable, ignoring flags like RADAR
   which would prevent TDLS off-channel communcation.
3. HT20 was explicitly required in the chandef, while not a requirement
   for TDLS off-channel.

Signed-off-by: Arik Nemtsov <arikx.nemtsov@intel.com>
Reviewed-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 21 insertions, 5 deletions

diff --git a/net/mac80211/tdls.c b/net/mac80211/tdls.c
index 159ebf1304b2..917088dfd696 100644
--- a/net/mac80211/tdls.c
+++ b/net/mac80211/tdls.c
@@ -68,17 +68,24 @@ ieee80211_tdls_add_subband(struct ieee80211_sub_if_data *sdata,
                 ch = ieee80211_get_channel(sdata->local->hw.wiphy, i);
                 if (ch) {
                         /* we will be active on the channel */
-                        u32 flags = IEEE80211_CHAN_DISABLED |
-                                    IEEE80211_CHAN_NO_IR;
                         cfg80211_chandef_create(&chandef, ch,
-                                                NL80211_CHAN_HT20);
-                        if (cfg80211_chandef_usable(sdata->local->hw.wiphy,
-                                                    &chandef, flags)) {
+                                                NL80211_CHAN_NO_HT);
+                        if (cfg80211_reg_can_beacon(sdata->local->hw.wiphy,
+                                                    &chandef,
+                                                    sdata->wdev.iftype)) {
                                 ch_cnt++;
+                                /*
+                                 * check if the next channel is also part of
+                                 * this allowed range
+                                 */
                                 continue;
                         }
                 }
 
+                /*
+                 * we've reached the end of a range, with allowed channels
+                 * found
+                 */
                 if (ch_cnt) {
                         u8 *pos = skb_put(skb, 2);
                         *pos++ = ieee80211_frequency_to_channel(subband_start);
@@ -89,6 +96,15 @@ ieee80211_tdls_add_subband(struct ieee80211_sub_if_data *sdata,
                 }
         }
 
+        /* all channels in the requested range are allowed - add them here */
+        if (ch_cnt) {
+                u8 *pos = skb_put(skb, 2);
+                *pos++ = ieee80211_frequency_to_channel(subband_start);
+                *pos++ = ch_cnt;
+
+                subband_cnt++;
+        }
+
         return subband_cnt;
 }