Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6

1 files changed, 54 insertions, 0 deletions

diff --git a/net/wireless/chan.c b/net/wireless/chan.c
index d0c92dddb26b..17cd0c04d139 100644
--- a/net/wireless/chan.c
+++ b/net/wireless/chan.c
@@ -44,6 +44,38 @@ 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;
+		break;
+	case NL80211_CHAN_HT40MINUS:
+		diff = -20;
+		break;
+	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 +100,28 @@ 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);