mac80211: Add capability to enable/disable beaconing

This patch adds a flag to notify drivers to start and stop
beaconing when needed, for example, during a scan run. Based
on Sujith's first patch to do the same, but now disables
beaconing for all virtual interfaces while scanning, has a
separate change flag and tracks user-space requests.

Signed-off-by: Sujith <Sujith.Manoharan@atheros.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

6 files changed, 66 insertions, 14 deletions

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 634c08de6acb..35643c55827a 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -646,10 +646,12 @@ struct ieee80211_if_init_conf {
  * @IEEE80211_IFCC_BSSID: The BSSID changed.
  * @IEEE80211_IFCC_BEACON: The beacon for this interface changed
  *      (currently AP and MESH only), use ieee80211_beacon_get().
+ * @IEEE80211_IFCC_BEACON_ENABLED: The enable_beacon value changed.
  */
 enum ieee80211_if_conf_change {
-        IEEE80211_IFCC_BSSID    = BIT(0),
-        IEEE80211_IFCC_BEACON   = BIT(1),
+        IEEE80211_IFCC_BSSID            = BIT(0),
+        IEEE80211_IFCC_BEACON           = BIT(1),
+        IEEE80211_IFCC_BEACON_ENABLED   = BIT(2),
 };
 
 /**
@@ -657,6 +659,8 @@ enum ieee80211_if_conf_change {
  *
  * @changed: parameters that have changed, see &enum ieee80211_if_conf_change.
  * @bssid: BSSID of the network we are associated to/creating.
+ * @enable_beacon: Indicates whether beacons can be sent.
+ *      This is valid only for AP/IBSS/MESH modes.
  *
  * This structure is passed to the config_interface() callback of
  * &struct ieee80211_hw.
@@ -664,6 +668,7 @@ enum ieee80211_if_conf_change {
 struct ieee80211_if_conf {
         u32 changed;
         const u8 *bssid;
+        bool enable_beacon;
 };
 
 /**
diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 3527de22cafb..a1a1344c5c4b 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -523,7 +523,8 @@ static int ieee80211_config_beacon(struct ieee80211_sub_if_data *sdata,
 
         kfree(old);
 
-        return ieee80211_if_config(sdata, IEEE80211_IFCC_BEACON);
+        return ieee80211_if_config(sdata, IEEE80211_IFCC_BEACON |
+                                          IEEE80211_IFCC_BEACON_ENABLED);
 }
 
 static int ieee80211_add_beacon(struct wiphy *wiphy, struct net_device *dev,
@@ -583,7 +584,7 @@ static int ieee80211_del_beacon(struct wiphy *wiphy, struct net_device *dev)
         synchronize_rcu();
         kfree(old);
 
-        return ieee80211_if_config(sdata, IEEE80211_IFCC_BEACON);
+        return ieee80211_if_config(sdata, IEEE80211_IFCC_BEACON_ENABLED);
 }
 
 /* Layer 2 Update frame (802.2 Type 1 LLC XID Update response) */
diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index 6f0fe3564ca4..8d5c19e4a1bc 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -168,7 +168,6 @@ int ieee80211_if_config(struct ieee80211_sub_if_data *sdata, u32 changed)
                 return 0;
 
         memset(&conf, 0, sizeof(conf));
-        conf.changed = changed;
 
         if (sdata->vif.type == NL80211_IFTYPE_STATION ||
             sdata->vif.type == NL80211_IFTYPE_ADHOC)
@@ -183,9 +182,50 @@ int ieee80211_if_config(struct ieee80211_sub_if_data *sdata, u32 changed)
                 return -EINVAL;
         }
 
+        switch (sdata->vif.type) {
+        case NL80211_IFTYPE_AP:
+        case NL80211_IFTYPE_ADHOC:
+        case NL80211_IFTYPE_MESH_POINT:
+                break;
+        default:
+                /* do not warn to simplify caller in scan.c */
+                changed &= ~IEEE80211_IFCC_BEACON_ENABLED;
+                if (WARN_ON(changed & IEEE80211_IFCC_BEACON))
+                        return -EINVAL;
+                changed &= ~IEEE80211_IFCC_BEACON;
+                break;
+        }
+
+        if (changed & IEEE80211_IFCC_BEACON_ENABLED) {
+                if (local->sw_scanning) {
+                        conf.enable_beacon = false;
+                } else {
+                        /*
+                         * Beacon should be enabled, but AP mode must
+                         * check whether there is a beacon configured.
+                         */
+                        switch (sdata->vif.type) {
+                        case NL80211_IFTYPE_AP:
+                                conf.enable_beacon =
+                                        !!rcu_dereference(sdata->u.ap.beacon);
+                                break;
+                        case NL80211_IFTYPE_ADHOC:
+                        case NL80211_IFTYPE_MESH_POINT:
+                                conf.enable_beacon = true;
+                                break;
+                        default:
+                                /* not reached */
+                                WARN_ON(1);
+                                break;
+                        }
+                }
+        }
+
         if (WARN_ON(!conf.bssid && (changed & IEEE80211_IFCC_BSSID)))
                 return -EINVAL;
 
+        conf.changed = changed;
+
         return local->ops->config_interface(local_to_hw(local),
                                             &sdata->vif, &conf);
 }
diff --git a/net/mac80211/mesh.c b/net/mac80211/mesh.c
index 2d573f8470d0..8a1fcaeee4f2 100644
--- a/net/mac80211/mesh.c
+++ b/net/mac80211/mesh.c
@@ -442,7 +442,8 @@ void ieee80211_start_mesh(struct ieee80211_sub_if_data *sdata)
 
         ifmsh->housekeeping = true;
         queue_work(local->hw.workqueue, &ifmsh->work);
-        ieee80211_if_config(sdata, IEEE80211_IFCC_BEACON);
+        ieee80211_if_config(sdata, IEEE80211_IFCC_BEACON |
+                                   IEEE80211_IFCC_BEACON_ENABLED);
 }
 
 void ieee80211_stop_mesh(struct ieee80211_sub_if_data *sdata)
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 9852da54f5e7..ec400479c5f6 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -1599,7 +1599,8 @@ static int ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
 
         ifsta->probe_resp = skb;
 
-        ieee80211_if_config(sdata, IEEE80211_IFCC_BEACON);
+        ieee80211_if_config(sdata, IEEE80211_IFCC_BEACON |
+                                   IEEE80211_IFCC_BEACON_ENABLED);
 
 
         rates = 0;
diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c
index a2caeed57f4e..8248d7b6ae82 100644
--- a/net/mac80211/scan.c
+++ b/net/mac80211/scan.c
@@ -20,6 +20,7 @@
 
 #include <linux/wireless.h>
 #include <linux/if_arp.h>
+#include <linux/rtnetlink.h>
 #include <net/mac80211.h>
 #include <net/iw_handler.h>
 
@@ -472,8 +473,8 @@ void ieee80211_scan_completed(struct ieee80211_hw *hw)
         netif_addr_unlock(local->mdev);
         netif_tx_unlock_bh(local->mdev);
 
-        rcu_read_lock();
-        list_for_each_entry_rcu(sdata, &local->interfaces, list) {
+        mutex_lock(&local->iflist_mtx);
+        list_for_each_entry(sdata, &local->interfaces, list) {
                 /* Tell AP we're back */
                 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
                         if (sdata->u.sta.flags & IEEE80211_STA_ASSOCIATED) {
@@ -482,8 +483,10 @@ void ieee80211_scan_completed(struct ieee80211_hw *hw)
                         }
                 } else
                         netif_tx_wake_all_queues(sdata->dev);
+
+                ieee80211_if_config(sdata, IEEE80211_IFCC_BEACON_ENABLED);
         }
-        rcu_read_unlock();
+        mutex_unlock(&local->iflist_mtx);
 
  done:
         ieee80211_mlme_notify_scan_completed(local);
@@ -491,7 +494,6 @@ void ieee80211_scan_completed(struct ieee80211_hw *hw)
 }
 EXPORT_SYMBOL(ieee80211_scan_completed);
 
-
 void ieee80211_scan_work(struct work_struct *work)
 {
         struct ieee80211_local *local =
@@ -633,8 +635,10 @@ int ieee80211_start_scan(struct ieee80211_sub_if_data *scan_sdata,
 
         local->sw_scanning = true;
 
-        rcu_read_lock();
-        list_for_each_entry_rcu(sdata, &local->interfaces, list) {
+        mutex_lock(&local->iflist_mtx);
+        list_for_each_entry(sdata, &local->interfaces, list) {
+                ieee80211_if_config(sdata, IEEE80211_IFCC_BEACON_ENABLED);
+
                 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
                         if (sdata->u.sta.flags & IEEE80211_STA_ASSOCIATED) {
                                 netif_tx_stop_all_queues(sdata->dev);
@@ -643,7 +647,7 @@ int ieee80211_start_scan(struct ieee80211_sub_if_data *scan_sdata,
                 } else
                         netif_tx_stop_all_queues(sdata->dev);
         }
-        rcu_read_unlock();
+        mutex_unlock(&local->iflist_mtx);
 
         if (ssid) {
                 local->scan_ssid_len = ssid_len;