cfg80211: allow beaconing after DFS CAC

Allow beconing after we pass Channel Availability Check (CAC).
Allow non-DFS and DFS channels mix. All DFS channels have to
be in NL80211_DFS_AVAILABLE state (pass CAC).

Signed-off-by: Janusz Dziedzic <janusz.dziedzic@tieto.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/net/wireless/chan.c b/net/wireless/chan.c
index 3b6daf8b47d92d20043b6146a1b008e8e521c25e..78559b5bbd1fe1d98c533f18dd1cc4fce4087baa 100644 (file)
--- a/net/wireless/chan.c
+++ b/net/wireless/chan.c
@@ -425,9 +425,9 @@ bool cfg80211_chandef_dfs_usable(struct wiphy *wiphy,
 }
 
 
-static bool cfg80211_secondary_chans_ok(struct wiphy *wiphy,
-                                       u32 center_freq, u32 bandwidth,
-                                       u32 prohibited_flags)
+static bool cfg80211_get_chans_dfs_available(struct wiphy *wiphy,
+                                            u32 center_freq,
+                                            u32 bandwidth)
 {
        struct ieee80211_channel *c;
        u32 freq, start_freq, end_freq;
@@ -435,18 +435,75 @@ static bool cfg80211_secondary_chans_ok(struct wiphy *wiphy,
        start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
        end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
 
+       /*
+        * Check entire range of channels for the bandwidth.
+        * If any channel in between is disabled or has not
+        * had gone through CAC return false
+        */
        for (freq = start_freq; freq <= end_freq; freq += 20) {
                c = ieee80211_get_channel(wiphy, freq);
                if (!c)
                        return false;
 
-               /* check for radar flags */
-               if ((prohibited_flags & c->flags & IEEE80211_CHAN_RADAR) &&
+               if (c->flags & IEEE80211_CHAN_DISABLED)
+                       return false;
+
+               if ((c->flags & IEEE80211_CHAN_RADAR)  &&
                    (c->dfs_state != NL80211_DFS_AVAILABLE))
                        return false;
+       }
+
+       return true;
+}
+
+static bool cfg80211_chandef_dfs_available(struct wiphy *wiphy,
+                               const struct cfg80211_chan_def *chandef)
+{
+       int width;
+       int r;
+
+       if (WARN_ON(!cfg80211_chandef_valid(chandef)))
+               return false;
+
+       width = cfg80211_chandef_get_width(chandef);
+       if (width < 0)
+               return false;
+
+       r = cfg80211_get_chans_dfs_available(wiphy, chandef->center_freq1,
+                                            width);
+
+       /* If any of channels unavailable for cf1 just return */
+       if (!r)
+               return r;
+
+       switch (chandef->width) {
+       case NL80211_CHAN_WIDTH_80P80:
+               WARN_ON(!chandef->center_freq2);
+               r = cfg80211_get_chans_dfs_available(wiphy,
+                                                    chandef->center_freq2,
+                                                    width);
+       default:
+               WARN_ON(chandef->center_freq2);
+               break;
+       }
+
+       return r;
+}
+
+
+static bool cfg80211_secondary_chans_ok(struct wiphy *wiphy,
+                                       u32 center_freq, u32 bandwidth,
+                                       u32 prohibited_flags)
+{
+       struct ieee80211_channel *c;
+       u32 freq, start_freq, end_freq;
 
-               /* check for the other flags */
-               if (c->flags & prohibited_flags & ~IEEE80211_CHAN_RADAR)
+       start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
+       end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
+
+       for (freq = start_freq; freq <= end_freq; freq += 20) {
+               c = ieee80211_get_channel(wiphy, freq);
+               if (!c || c->flags & prohibited_flags)
                        return false;
        }
 
@@ -552,13 +609,19 @@ bool cfg80211_reg_can_beacon(struct wiphy *wiphy,
                             struct cfg80211_chan_def *chandef)
 {
        bool res;
+       u32 prohibited_flags = IEEE80211_CHAN_DISABLED |
+                              IEEE80211_CHAN_NO_IR |
+                              IEEE80211_CHAN_RADAR;
 
        trace_cfg80211_reg_can_beacon(wiphy, chandef);
 
-       res = cfg80211_chandef_usable(wiphy, chandef,
-                                     IEEE80211_CHAN_DISABLED |
-                                     IEEE80211_CHAN_NO_IR |
-                                     IEEE80211_CHAN_RADAR);
+       if (cfg80211_chandef_dfs_required(wiphy, chandef) > 0 &&
+           cfg80211_chandef_dfs_available(wiphy, chandef)) {
+               /* We can skip IEEE80211_CHAN_NO_IR if chandef dfs available */
+               prohibited_flags = IEEE80211_CHAN_DISABLED;
+       }
+
+       res = cfg80211_chandef_usable(wiphy, chandef, prohibited_flags);
 
        trace_cfg80211_return_bool(res);
        return res;