cfg80211: fix extension channel checks to initiate communication

[net-next-2.6.git] / net / wireless / chan.c

diff --git a/net/wireless/chan.c b/net/wireless/chan.c
index d0c92dddb26bddb5b3d55a82ebf39fa8917e446c..c8d190d911e46984b5eb43ebf3f625e035a32bed 100644 (file)
--- a/net/wireless/chan.c
+++ b/net/wireless/chan.c
@@ -44,6 +44,36 @@ rdev_freq_to_chan(struct cfg80211_registered_device *rdev,
        return chan;
 }
 
+static bool can_beacon_sec_chan(struct wiphy *wiphy,
+                               struct ieee80211_channel *chan,
+                               enum nl80211_channel_type channel_type)
+{
+       struct ieee80211_channel *sec_chan;
+       int diff;
+
+       switch (channel_type) {
+       case NL80211_CHAN_HT40PLUS:
+               diff = 20;
+       case NL80211_CHAN_HT40MINUS:
+               diff = -20;
+       default:
+               return false;
+       }
+
+       sec_chan = ieee80211_get_channel(wiphy, chan->center_freq + diff);
+       if (!sec_chan)
+               return false;
+
+       /* we'll need a DFS capability later */
+       if (sec_chan->flags & (IEEE80211_CHAN_DISABLED |
+                              IEEE80211_CHAN_PASSIVE_SCAN |
+                              IEEE80211_CHAN_NO_IBSS |
+                              IEEE80211_CHAN_RADAR))
+               return false;
+
+       return true;
+}
+
 int cfg80211_set_freq(struct cfg80211_registered_device *rdev,
                      struct wireless_dev *wdev, int freq,
                      enum nl80211_channel_type channel_type)
@@ -68,6 +98,28 @@ int cfg80211_set_freq(struct cfg80211_registered_device *rdev,
        if (!chan)
                return -EINVAL;
 
+       /* Both channels should be able to initiate communication */
+       if (wdev && (wdev->iftype == NL80211_IFTYPE_ADHOC ||
+                    wdev->iftype == NL80211_IFTYPE_AP ||
+                    wdev->iftype == NL80211_IFTYPE_AP_VLAN ||
+                    wdev->iftype == NL80211_IFTYPE_MESH_POINT ||
+                    wdev->iftype == NL80211_IFTYPE_P2P_GO)) {
+               switch (channel_type) {
+               case NL80211_CHAN_HT40PLUS:
+               case NL80211_CHAN_HT40MINUS:
+                       if (!can_beacon_sec_chan(&rdev->wiphy, chan,
+                                                channel_type)) {
+                               printk(KERN_DEBUG
+                                      "cfg80211: Secondary channel not "
+                                      "allowed to initiate communication\n");
+                               return -EINVAL;
+                       }
+                       break;
+               default:
+                       break;
+               }
+       }
+
        result = rdev->ops->set_channel(&rdev->wiphy,
                                        wdev ? wdev->netdev : NULL,
                                        chan, channel_type);