nl80211/cfg80211: enable DFS for IBSS mode

To use DFS in IBSS mode, userspace is required to react to radar events.
It can inform nl80211 that it is capable of doing so by adding a
NL80211_ATTR_HANDLE_DFS attribute when joining the IBSS.

This attribute is supplied to let the kernelspace know that the
userspace application can and will handle radar events, e.g. by
intiating channel switches to a valid channel. DFS channels may
only be used if this attribute is supplied and the driver supports
it. Driver support will be checked even if a channel without DFS
will be initially joined, as a DFS channel may be chosen later.

Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Mathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
[fix attribute name in commit message]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 5db5fe24eff6..b1acf36e5f45 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -1664,6 +1664,9 @@ struct cfg80211_disassoc_request {
  *      sets/clears %NL80211_STA_FLAG_AUTHORIZED. If true, the driver is
  *      required to assume that the port is unauthorized until authorized by
  *      user space. Otherwise, port is marked authorized by default.
+ * @userspace_handles_dfs: whether user space controls DFS operation, i.e.
+ *      changes the channel when a radar is detected. This is required
+ *      to operate on DFS channels.
  * @basic_rates: bitmap of basic rates to use when creating the IBSS
  * @mcast_rate: per-band multicast rate index + 1 (0: disabled)
  * @ht_capa:  HT Capabilities over-rides.  Values set in ht_capa_mask
@@ -1681,6 +1684,7 @@ struct cfg80211_ibss_params {
         bool channel_fixed;
         bool privacy;
         bool control_port;
+        bool userspace_handles_dfs;
         int mcast_rate[IEEE80211_NUM_BANDS];
         struct ieee80211_ht_cap ht_capa;
         struct ieee80211_ht_cap ht_capa_mask;
@@ -3061,6 +3065,7 @@ struct cfg80211_cached_keys;
  * @conn: (private) cfg80211 software SME connection state machine data
  * @connect_keys: (private) keys to set after connection is established
  * @ibss_fixed: (private) IBSS is using fixed BSSID
+ * @ibss_dfs_possible: (private) IBSS may change to a DFS channel
  * @event_list: (private) list for internal event processing
  * @event_lock: (private) lock for event list
  */
@@ -3099,6 +3104,7 @@ struct wireless_dev {
         struct ieee80211_channel *channel;
 
         bool ibss_fixed;
+        bool ibss_dfs_possible;
 
         bool ps;
         int ps_timeout;