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, 9 insertions, 0 deletions

diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index f2aef2a7a570..f752e9821e71 100644
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -1501,6 +1501,13 @@ enum nl80211_commands {
  * @NL80211_ATTR_STA_SUPPORTED_OPER_CLASSES: array of supported
  *      supported operating classes.
  *
+ * @NL80211_ATTR_HANDLE_DFS: A flag indicating whether user space
+ *      controls DFS operation in IBSS mode. If the flag is included in
+ *      %NL80211_CMD_JOIN_IBSS request, the driver will allow use of DFS
+ *      channels and reports radar events to userspace. Userspace is required
+ *      to react to radar events, e.g. initiate a channel switch or leave the
+ *      IBSS network.
+ *
  * @NL80211_ATTR_MAX: highest attribute number currently defined
  * @__NL80211_ATTR_AFTER_LAST: internal use
  */
@@ -1815,6 +1822,8 @@ enum nl80211_attrs {
 
         NL80211_ATTR_STA_SUPPORTED_OPER_CLASSES,
 
+        NL80211_ATTR_HANDLE_DFS,
+
         /* add attributes here, update the policy in nl80211.c */
 
         __NL80211_ATTR_AFTER_LAST,