cfg80211: introduce cfg80211_get_chan_state

Helper function for finding out which channel is
used by a given interface.

An exclusive channel can be used only by a single
interface. This is mainly for non-fixed channel
IBSS handling.

Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

2 files changed, 63 insertions, 0 deletions

diff --git a/net/wireless/chan.c b/net/wireless/chan.c
index c1999e45a07c..167e7cb60089 100644
--- a/net/wireless/chan.c
+++ b/net/wireless/chan.c
@@ -92,3 +92,54 @@ int cfg80211_set_monitor_channel(struct cfg80211_registered_device *rdev,
 
         return rdev->ops->set_monitor_channel(&rdev->wiphy, chan, chantype);
 }
+
+void
+cfg80211_get_chan_state(struct cfg80211_registered_device *rdev,
+                        struct wireless_dev *wdev,
+                        struct ieee80211_channel **chan,
+                        enum cfg80211_chan_mode *chanmode)
+{
+        *chan = NULL;
+        *chanmode = CHAN_MODE_UNDEFINED;
+
+        ASSERT_RDEV_LOCK(rdev);
+        ASSERT_WDEV_LOCK(wdev);
+
+        if (!netif_running(wdev->netdev))
+                return;
+
+        switch (wdev->iftype) {
+        case NL80211_IFTYPE_ADHOC:
+                if (wdev->current_bss) {
+                        *chan = wdev->current_bss->pub.channel;
+                        *chanmode = wdev->ibss_fixed
+                                  ? CHAN_MODE_SHARED
+                                  : CHAN_MODE_EXCLUSIVE;
+                        return;
+                }
+        case NL80211_IFTYPE_STATION:
+        case NL80211_IFTYPE_P2P_CLIENT:
+                if (wdev->current_bss) {
+                        *chan = wdev->current_bss->pub.channel;
+                        *chanmode = CHAN_MODE_SHARED;
+                        return;
+                }
+                break;
+        case NL80211_IFTYPE_AP:
+        case NL80211_IFTYPE_P2P_GO:
+        case NL80211_IFTYPE_MESH_POINT:
+                *chan = wdev->channel;
+                *chanmode = CHAN_MODE_SHARED;
+                return;
+        case NL80211_IFTYPE_MONITOR:
+        case NL80211_IFTYPE_AP_VLAN:
+        case NL80211_IFTYPE_WDS:
+                /* these interface types don't really have a channel */
+                return;
+        case NL80211_IFTYPE_UNSPECIFIED:
+        case NUM_NL80211_IFTYPES:
+                WARN_ON(1);
+        }
+
+        return;
+}
diff --git a/net/wireless/core.h b/net/wireless/core.h
index fef476d2117e..56f18c2eb919 100644
--- a/net/wireless/core.h
+++ b/net/wireless/core.h
@@ -241,6 +241,12 @@ struct cfg80211_cached_keys {
         int def, defmgmt;
 };
 
+enum cfg80211_chan_mode {
+        CHAN_MODE_UNDEFINED,
+        CHAN_MODE_SHARED,
+        CHAN_MODE_EXCLUSIVE,
+};
+
 
 /* free object */
 extern void cfg80211_dev_free(struct cfg80211_registered_device *rdev);
@@ -419,6 +425,12 @@ cfg80211_can_add_interface(struct cfg80211_registered_device *rdev,
         return cfg80211_can_change_interface(rdev, NULL, iftype);
 }
 
+void
+cfg80211_get_chan_state(struct cfg80211_registered_device *rdev,
+                        struct wireless_dev *wdev,
+                        struct ieee80211_channel **chan,
+                        enum cfg80211_chan_mode *chanmode);
+
 struct ieee80211_channel *
 rdev_freq_to_chan(struct cfg80211_registered_device *rdev,
                   int freq, enum nl80211_channel_type channel_type);