nl/cfg80211: force scan using an AP vif if requested

If the user wants to scan using a vif configured as AP,
cfg80211 must give him a chance to do it, even if this
will disrupt the stations performance due to off-channel
scanning. To do so, this patch adds a 'force' flag to the
SCAN_TRIGGER command which tells cfg80211 to perform the
scanning operation even if the vif is an AP and the
beaconing has already started.

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index 0e6277a06c29..617d0fbfc96f 100644
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -3050,6 +3050,7 @@ enum nl80211_ap_sme_features {
  *      mode
  * @NL80211_FEATURE_LOW_PRIORITY_SCAN: This driver supports low priority scan
  * @NL80211_FEATURE_SCAN_FLUSH: Scan flush is supported
+ * @NL80211_FEATURE_AP_SCAN: Support scanning using an AP vif
  */
 enum nl80211_feature_flags {
         NL80211_FEATURE_SK_TX_STATUS                    = 1 << 0,
@@ -3060,6 +3061,7 @@ enum nl80211_feature_flags {
         NL80211_FEATURE_SAE                             = 1 << 5,
         NL80211_FEATURE_LOW_PRIORITY_SCAN               = 1 << 6,
         NL80211_FEATURE_SCAN_FLUSH                      = 1 << 7,
+        NL80211_FEATURE_AP_SCAN                         = 1 << 8,
 };
 
 /**
@@ -3103,10 +3105,16 @@ enum nl80211_connect_failed_reason {
  *
  * @NL80211_SCAN_FLAG_LOW_PRIORITY: scan request has low priority
  * @NL80211_SCAN_FLAG_FLUSH: flush cache before scanning
+ * @NL80211_SCAN_FLAG_AP: force a scan even if the interface is configured
+ *      as AP and the beaconing has already been configured. This attribute is
+ *      dangerous because will destroy stations performance as a lot of frames
+ *      will be lost while scanning off-channel, therefore it must be used only
+ *      when really needed
  */
 enum nl80211_scan_flags {
         NL80211_SCAN_FLAG_LOW_PRIORITY                  = 1<<0,
         NL80211_SCAN_FLAG_FLUSH                         = 1<<1,
+        NL80211_SCAN_FLAG_AP                            = 1<<2,
 };
 
 #endif /* __LINUX_NL80211_H */