4 files changed, 111 insertions, 1 deletions

diff --git a/net/mac80211/Makefile b/net/mac80211/Makefile
index 04420291e7ad..84b48ba8a77e 100644
--- a/net/mac80211/Makefile
+++ b/net/mac80211/Makefile
@@ -23,7 +23,8 @@ mac80211-y := \
 	key.o \
 	util.o \
 	wme.o \
-	event.o
+	event.o \
+	chan.o
 
 mac80211-$(CONFIG_MAC80211_LEDS) += led.o
 mac80211-$(CONFIG_MAC80211_DEBUGFS) += \
diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index b575a5066219..414b7dd7d7fd 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -1161,11 +1161,24 @@ static int ieee80211_set_txq_params(struct wiphy *wiphy,
 }
 
 static int ieee80211_set_channel(struct wiphy *wiphy,
+				 struct net_device *netdev,
 				 struct ieee80211_channel *chan,
 				 enum nl80211_channel_type channel_type)
 {
 	struct ieee80211_local *local = wiphy_priv(wiphy);
 
+	switch (ieee80211_get_channel_mode(local, NULL)) {
+	case CHAN_MODE_HOPPING:
+		return -EBUSY;
+	case CHAN_MODE_FIXED:
+		if (local->oper_channel == chan &&
+		    local->oper_channel_type == channel_type)
+			return 0;
+		return -EBUSY;
+	case CHAN_MODE_UNDEFINED:
+		break;
+	}
+
 	local->oper_channel = chan;
 	local->oper_channel_type = channel_type;
 
@@ -1213,6 +1226,20 @@ static int ieee80211_auth(struct wiphy *wiphy, struct net_device *dev,
 static int ieee80211_assoc(struct wiphy *wiphy, struct net_device *dev,
 			   struct cfg80211_assoc_request *req)
 {
+	struct ieee80211_local *local = wiphy_priv(wiphy);
+	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+
+	switch (ieee80211_get_channel_mode(local, sdata)) {
+	case CHAN_MODE_HOPPING:
+		return -EBUSY;
+	case CHAN_MODE_FIXED:
+		if (local->oper_channel == req->bss->channel)
+			break;
+		return -EBUSY;
+	case CHAN_MODE_UNDEFINED:
+		break;
+	}
+
 	return ieee80211_mgd_assoc(IEEE80211_DEV_TO_SUB_IF(dev), req);
 }
 
@@ -1235,8 +1262,22 @@ static int ieee80211_disassoc(struct wiphy *wiphy, struct net_device *dev,
 static int ieee80211_join_ibss(struct wiphy *wiphy, struct net_device *dev,
 			       struct cfg80211_ibss_params *params)
 {
+	struct ieee80211_local *local = wiphy_priv(wiphy);
 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 
+	switch (ieee80211_get_channel_mode(local, sdata)) {
+	case CHAN_MODE_HOPPING:
+		return -EBUSY;
+	case CHAN_MODE_FIXED:
+		if (!params->channel_fixed)
+			return -EBUSY;
+		if (local->oper_channel == params->channel)
+			break;
+		return -EBUSY;
+	case CHAN_MODE_UNDEFINED:
+		break;
+	}
+
 	return ieee80211_ibss_join(sdata, params);
 }
 
diff --git a/net/mac80211/chan.c b/net/mac80211/chan.c
new file mode 100644
index 000000000000..08f3832661a5
--- /dev/null
+++ b/net/mac80211/chan.c
@@ -0,0 +1,57 @@
+/*
+ * mac80211 - channel management
+ */
+
+#include "ieee80211_i.h"
+
+enum ieee80211_chan_mode
+__ieee80211_get_channel_mode(struct ieee80211_local *local,
+			     struct ieee80211_sub_if_data *ignore)
+{
+	struct ieee80211_sub_if_data *sdata;
+
+	WARN_ON(!mutex_is_locked(&local->iflist_mtx));
+
+	list_for_each_entry(sdata, &local->interfaces, list) {
+		if (sdata == ignore)
+			continue;
+
+		if (!ieee80211_sdata_running(sdata))
+			continue;
+
+		if (sdata->vif.type == NL80211_IFTYPE_MONITOR)
+			continue;
+
+		if (sdata->vif.type == NL80211_IFTYPE_STATION &&
+		    !sdata->u.mgd.associated)
+			continue;
+
+		if (sdata->vif.type == NL80211_IFTYPE_ADHOC) {
+			if (!sdata->u.ibss.ssid_len)
+				continue;
+			if (!sdata->u.ibss.fixed_channel)
+				return CHAN_MODE_HOPPING;
+		}
+
+		if (sdata->vif.type == NL80211_IFTYPE_AP &&
+		    !sdata->u.ap.beacon)
+			continue;
+
+		return CHAN_MODE_FIXED;
+	}
+
+	return CHAN_MODE_UNDEFINED;
+}
+
+enum ieee80211_chan_mode
+ieee80211_get_channel_mode(struct ieee80211_local *local,
+			   struct ieee80211_sub_if_data *ignore)
+{
+	enum ieee80211_chan_mode mode;
+
+	mutex_lock(&local->iflist_mtx);
+	mode = __ieee80211_get_channel_mode(local, ignore);
+	mutex_unlock(&local->iflist_mtx);
+
+	return mode;
+}
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index c8077a3647c6..359edff31471 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -1229,6 +1229,17 @@ int ieee80211_wk_remain_on_channel(struct ieee80211_sub_if_data *sdata,
 int ieee80211_wk_cancel_remain_on_channel(
 	struct ieee80211_sub_if_data *sdata, u64 cookie);
 
+/* channel management */
+enum ieee80211_chan_mode {
+	CHAN_MODE_UNDEFINED,
+	CHAN_MODE_HOPPING,
+	CHAN_MODE_FIXED,
+};
+
+enum ieee80211_chan_mode
+ieee80211_get_channel_mode(struct ieee80211_local *local,
+			   struct ieee80211_sub_if_data *ignore);
+
 #ifdef CONFIG_MAC80211_NOINLINE
 #define debug_noinline noinline
 #else