mac80211: add beacon filtering support

Add IEEE80211_HW_BEACON_FILTERING flag so that driver inform that it supports beacon filtering. Drivers need to call the new function ieee80211_beacon_loss() to notify about beacon loss. Signed-off-by: Kalle Valo <kalle.valo@nokia.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: add beacon filtering support
Add IEEE80211_HW_BEACON_FILTERING flag so that driver inform that it supports beacon filtering. Drivers need to call the new function ieee80211_beacon_loss() to notify about beacon loss. Signed-off-by: Kalle Valo <kalle.valo@nokia.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
Kalle Valo · John W. Linville
1 parent a08c1c1ac0
Showing 5 changed files with 92 additions and 1 deletions Side-by-side Diff
Documentation/DocBook/mac80211.tmpl
include/net/mac80211.h
net/mac80211/ieee80211_i.h
net/mac80211/iface.c
net/mac80211/mlme.c
@@ -227,6 +227,12 @@
 !Pinclude/net/mac80211.h Powersave support
     </chapter>
  
+    <chapter id="beacon-filter">
+      <title>Beacon filter support</title>
+!Pinclude/net/mac80211.h Beacon filter support
+!Finclude/net/mac80211.h ieee80211_beacon_loss
+    </chapter>
+
     <chapter id="qos">
       <title>Multiple queues and QoS support</title>
       <para>TBD</para>
@@ -882,6 +882,10 @@
  *
  * @IEEE80211_HW_MFP_CAPABLE:
  *	Hardware supports management frame protection (MFP, IEEE 802.11w).
+ *
+ * @IEEE80211_HW_BEACON_FILTER:
+ *	Hardware supports dropping of irrelevant beacon frames to
+ *	avoid waking up cpu.
  */
 enum ieee80211_hw_flags {
 	IEEE80211_HW_RX_INCLUDES_FCS			= 1<<1,
@@ -897,6 +901,7 @@
 	IEEE80211_HW_PS_NULLFUNC_STACK			= 1<<11,
 	IEEE80211_HW_SUPPORTS_DYNAMIC_PS		= 1<<12,
 	IEEE80211_HW_MFP_CAPABLE			= 1<<13,
+	IEEE80211_HW_BEACON_FILTER			= 1<<14,
 };
  
 /**
@@ -1121,6 +1126,24 @@
  */
  
 /**
+ * DOC: Beacon filter support
+ *
+ * Some hardware have beacon filter support to reduce host cpu wakeups
+ * which will reduce system power consumption. It usuallly works so that
+ * the firmware creates a checksum of the beacon but omits all constantly
+ * changing elements (TSF, TIM etc). Whenever the checksum changes the
+ * beacon is forwarded to the host, otherwise it will be just dropped. That
+ * way the host will only receive beacons where some relevant information
+ * (for example ERP protection or WMM settings) have changed.
+ *
+ * Beacon filter support is informed with %IEEE80211_HW_BEACON_FILTER flag.
+ * The driver needs to enable beacon filter support whenever power save is
+ * enabled, that is %IEEE80211_CONF_PS is set. When power save is enabled,
+ * the stack will not check for beacon miss at all and the driver needs to
+ * notify about complete loss of beacons with ieee80211_beacon_loss().
+ */
+
+/**
  * DOC: Frame filtering
  *
  * mac80211 requires to see many management frames for proper
@@ -1970,6 +1993,16 @@
 struct ieee80211_sta *ieee80211_find_sta(struct ieee80211_hw *hw,
 					 const u8 *addr);
  
+/**
+ * ieee80211_beacon_loss - inform hardware does not receive beacons
+ *
+ * @vif: &struct ieee80211_vif pointer from &struct ieee80211_if_init_conf.
+ *
+ * When beacon filtering is enabled with IEEE80211_HW_BEACON_FILTERING and
+ * IEEE80211_CONF_PS is set, the driver needs to inform whenever the
+ * hardware is not receiving beacons with this function.
+ */
+void ieee80211_beacon_loss(struct ieee80211_vif *vif);
  
 /* Rate control API */
  
@@ -275,6 +275,7 @@
 	struct timer_list chswitch_timer;
 	struct work_struct work;
 	struct work_struct chswitch_work;
+	struct work_struct beacon_loss_work;
  
 	u8 bssid[ETH_ALEN], prev_bssid[ETH_ALEN];
  
@@ -1086,6 +1087,7 @@
 			     int powersave);
 void ieee80211_sta_rx_notify(struct ieee80211_sub_if_data *sdata,
 			     struct ieee80211_hdr *hdr);
+void ieee80211_beacon_loss_work(struct work_struct *work);
  
 void ieee80211_wake_queues_by_reason(struct ieee80211_hw *hw,
 				     enum queue_stop_reason reason);
@@ -477,6 +477,9 @@
 		 */
 		cancel_work_sync(&sdata->u.mgd.work);
 		cancel_work_sync(&sdata->u.mgd.chswitch_work);
+
+		cancel_work_sync(&sdata->u.mgd.beacon_loss_work);
+
 		/*
 		 * When we get here, the interface is marked down.
 		 * Call synchronize_rcu() to wait for the RX path
@@ -610,6 +610,8 @@
 		bss_info_changed |= ieee80211_handle_bss_capability(sdata,
 			bss->cbss.capability, bss->has_erp_value, bss->erp_value);
  
+		cfg80211_hold_bss(&bss->cbss);
+
 		ieee80211_rx_bss_put(local, bss);
 	}
  
@@ -751,6 +753,8 @@
 {
 	struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
 	struct ieee80211_local *local = sdata->local;
+	struct ieee80211_conf *conf = &local_to_hw(local)->conf;
+	struct ieee80211_bss *bss;
 	struct sta_info *sta;
 	u32 changed = 0, config_changed = 0;
  
@@ -774,6 +778,15 @@
  
 	ieee80211_sta_tear_down_BA_sessions(sta);
  
+	bss = ieee80211_rx_bss_get(local, ifmgd->bssid,
+				   conf->channel->center_freq,
+				   ifmgd->ssid, ifmgd->ssid_len);
+
+	if (bss) {
+		cfg80211_unhold_bss(&bss->cbss);
+		ieee80211_rx_bss_put(local, bss);
+	}
+
 	if (self_disconnected) {
 		if (deauth)
 			ieee80211_send_deauth_disassoc(sdata,
@@ -925,6 +938,33 @@
 			  jiffies + IEEE80211_MONITORING_INTERVAL);
 }
  
+void ieee80211_beacon_loss_work(struct work_struct *work)
+{
+	struct ieee80211_sub_if_data *sdata =
+		container_of(work, struct ieee80211_sub_if_data,
+			     u.mgd.beacon_loss_work);
+	struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
+
+	printk(KERN_DEBUG "%s: driver reports beacon loss from AP %pM "
+	       "- sending probe request\n", sdata->dev->name,
+	       sdata->u.mgd.bssid);
+
+	ifmgd->flags |= IEEE80211_STA_PROBEREQ_POLL;
+	ieee80211_send_probe_req(sdata, ifmgd->bssid, ifmgd->ssid,
+				 ifmgd->ssid_len, NULL, 0);
+
+	mod_timer(&ifmgd->timer, jiffies + IEEE80211_MONITORING_INTERVAL);
+}
+
+void ieee80211_beacon_loss(struct ieee80211_vif *vif)
+{
+	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
+
+	queue_work(sdata->local->hw.workqueue,
+		   &sdata->u.mgd.beacon_loss_work);
+}
+EXPORT_SYMBOL(ieee80211_beacon_loss);
+
 static void ieee80211_associated(struct ieee80211_sub_if_data *sdata)
 {
 	struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
@@ -959,7 +999,13 @@
 		goto unlock;
 	}
  
-	if (time_after(jiffies,
+	/*
+	 * Beacon filtering is only enabled with power save and then the
+	 * stack should not check for beacon loss.
+	 */
+	if (!((local->hw.flags & IEEE80211_HW_BEACON_FILTER) &&
+	      (local->hw.conf.flags & IEEE80211_CONF_PS)) &&
+	    time_after(jiffies,
 		       ifmgd->last_beacon + IEEE80211_MONITORING_INTERVAL)) {
 		printk(KERN_DEBUG "%s: beacon loss from AP %pM "
 		       "- sending probe request\n",
@@ -1869,6 +1915,7 @@
 	ifmgd = &sdata->u.mgd;
 	INIT_WORK(&ifmgd->work, ieee80211_sta_work);
 	INIT_WORK(&ifmgd->chswitch_work, ieee80211_chswitch_work);
+	INIT_WORK(&ifmgd->beacon_loss_work, ieee80211_beacon_loss_work);
 	setup_timer(&ifmgd->timer, ieee80211_sta_timer,
 		    (unsigned long) sdata);
 	setup_timer(&ifmgd->chswitch_timer, ieee80211_chswitch_timer,
...	...	@@ -227,6 +227,12 @@
227	227	!Pinclude/net/mac80211.h Powersave support
228	228	</chapter>
229	229
	230	+ <chapter id="beacon-filter">
	231	+ <title>Beacon filter support</title>
	232	+!Pinclude/net/mac80211.h Beacon filter support
	233	+!Finclude/net/mac80211.h ieee80211_beacon_loss
	234	+ </chapter>
	235	+
230	236	<chapter id="qos">
231	237	<title>Multiple queues and QoS support</title>
232	238	<para>TBD</para>
...	...	@@ -882,6 +882,10 @@
882	882	*
883	883	* @IEEE80211_HW_MFP_CAPABLE:
884	884	* Hardware supports management frame protection (MFP, IEEE 802.11w).
	885	+ *
	886	+ * @IEEE80211_HW_BEACON_FILTER:
	887	+ * Hardware supports dropping of irrelevant beacon frames to
	888	+ * avoid waking up cpu.
885	889	*/
886	890	enum ieee80211_hw_flags {
887	891	IEEE80211_HW_RX_INCLUDES_FCS = 1<<1,
...	...	@@ -897,6 +901,7 @@
897	901	IEEE80211_HW_PS_NULLFUNC_STACK = 1<<11,
898	902	IEEE80211_HW_SUPPORTS_DYNAMIC_PS = 1<<12,
899	903	IEEE80211_HW_MFP_CAPABLE = 1<<13,
	904	+ IEEE80211_HW_BEACON_FILTER = 1<<14,
900	905	};
901	906
902	907	/**
...	...	@@ -1121,6 +1126,24 @@
1121	1126	*/
1122	1127
1123	1128	/**
	1129	+ * DOC: Beacon filter support
	1130	+ *
	1131	+ * Some hardware have beacon filter support to reduce host cpu wakeups
	1132	+ * which will reduce system power consumption. It usuallly works so that
	1133	+ * the firmware creates a checksum of the beacon but omits all constantly
	1134	+ * changing elements (TSF, TIM etc). Whenever the checksum changes the
	1135	+ * beacon is forwarded to the host, otherwise it will be just dropped. That
	1136	+ * way the host will only receive beacons where some relevant information
	1137	+ * (for example ERP protection or WMM settings) have changed.
	1138	+ *
	1139	+ * Beacon filter support is informed with %IEEE80211_HW_BEACON_FILTER flag.
	1140	+ * The driver needs to enable beacon filter support whenever power save is
	1141	+ * enabled, that is %IEEE80211_CONF_PS is set. When power save is enabled,
	1142	+ * the stack will not check for beacon miss at all and the driver needs to
	1143	+ * notify about complete loss of beacons with ieee80211_beacon_loss().
	1144	+ */
	1145	+
	1146	+/**
1124	1147	* DOC: Frame filtering
1125	1148	*
1126	1149	* mac80211 requires to see many management frames for proper
...	...	@@ -1970,6 +1993,16 @@
1970	1993	struct ieee80211_sta ieee80211_find_sta(struct ieee80211_hw hw,
1971	1994	const u8 *addr);
1972	1995
	1996	+/**
	1997	+ * ieee80211_beacon_loss - inform hardware does not receive beacons
	1998	+ *
	1999	+ * @vif: &struct ieee80211_vif pointer from &struct ieee80211_if_init_conf.
	2000	+ *
	2001	+ * When beacon filtering is enabled with IEEE80211_HW_BEACON_FILTERING and
	2002	+ * IEEE80211_CONF_PS is set, the driver needs to inform whenever the
	2003	+ * hardware is not receiving beacons with this function.
	2004	+ */
	2005	+void ieee80211_beacon_loss(struct ieee80211_vif *vif);
1973	2006
1974	2007	/* Rate control API */
1975	2008
...	...	@@ -275,6 +275,7 @@
275	275	struct timer_list chswitch_timer;
276	276	struct work_struct work;
277	277	struct work_struct chswitch_work;
	278	+ struct work_struct beacon_loss_work;
278	279
279	280	u8 bssid[ETH_ALEN], prev_bssid[ETH_ALEN];
280	281
...	...	@@ -1086,6 +1087,7 @@
1086	1087	int powersave);
1087	1088	void ieee80211_sta_rx_notify(struct ieee80211_sub_if_data *sdata,
1088	1089	struct ieee80211_hdr *hdr);
	1090	+void ieee80211_beacon_loss_work(struct work_struct *work);
1089	1091
1090	1092	void ieee80211_wake_queues_by_reason(struct ieee80211_hw *hw,
1091	1093	enum queue_stop_reason reason);
...	...	@@ -477,6 +477,9 @@
477	477	*/
478	478	cancel_work_sync(&sdata->u.mgd.work);
479	479	cancel_work_sync(&sdata->u.mgd.chswitch_work);
	480	+
	481	+ cancel_work_sync(&sdata->u.mgd.beacon_loss_work);
	482	+
480	483	/*
481	484	* When we get here, the interface is marked down.
482	485	* Call synchronize_rcu() to wait for the RX path
...	...	@@ -610,6 +610,8 @@
610	610	bss_info_changed \|= ieee80211_handle_bss_capability(sdata,
611	611	bss->cbss.capability, bss->has_erp_value, bss->erp_value);
612	612
	613	+ cfg80211_hold_bss(&bss->cbss);
	614	+
613	615	ieee80211_rx_bss_put(local, bss);
614	616	}
615	617
...	...	@@ -751,6 +753,8 @@
751	753	{
752	754	struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
753	755	struct ieee80211_local *local = sdata->local;
	756	+ struct ieee80211_conf *conf = &local_to_hw(local)->conf;
	757	+ struct ieee80211_bss *bss;
754	758	struct sta_info *sta;
755	759	u32 changed = 0, config_changed = 0;
756	760
...	...	@@ -774,6 +778,15 @@
774	778
775	779	ieee80211_sta_tear_down_BA_sessions(sta);
776	780
	781	+ bss = ieee80211_rx_bss_get(local, ifmgd->bssid,
	782	+ conf->channel->center_freq,
	783	+ ifmgd->ssid, ifmgd->ssid_len);
	784	+
	785	+ if (bss) {
	786	+ cfg80211_unhold_bss(&bss->cbss);
	787	+ ieee80211_rx_bss_put(local, bss);
	788	+ }
	789	+
777	790	if (self_disconnected) {
778	791	if (deauth)
779	792	ieee80211_send_deauth_disassoc(sdata,
...	...	@@ -925,6 +938,33 @@
925	938	jiffies + IEEE80211_MONITORING_INTERVAL);
926	939	}
927	940
	941	+void ieee80211_beacon_loss_work(struct work_struct *work)
	942	+{
	943	+ struct ieee80211_sub_if_data *sdata =
	944	+ container_of(work, struct ieee80211_sub_if_data,
	945	+ u.mgd.beacon_loss_work);
	946	+ struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
	947	+
	948	+ printk(KERN_DEBUG "%s: driver reports beacon loss from AP %pM "
	949	+ "- sending probe request\n", sdata->dev->name,
	950	+ sdata->u.mgd.bssid);
	951	+
	952	+ ifmgd->flags \|= IEEE80211_STA_PROBEREQ_POLL;
	953	+ ieee80211_send_probe_req(sdata, ifmgd->bssid, ifmgd->ssid,
	954	+ ifmgd->ssid_len, NULL, 0);
	955	+
	956	+ mod_timer(&ifmgd->timer, jiffies + IEEE80211_MONITORING_INTERVAL);
	957	+}
	958	+
	959	+void ieee80211_beacon_loss(struct ieee80211_vif *vif)
	960	+{
	961	+ struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
	962	+
	963	+ queue_work(sdata->local->hw.workqueue,
	964	+ &sdata->u.mgd.beacon_loss_work);
	965	+}
	966	+EXPORT_SYMBOL(ieee80211_beacon_loss);
	967	+
928	968	static void ieee80211_associated(struct ieee80211_sub_if_data *sdata)
929	969	{
930	970	struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
...	...	@@ -959,7 +999,13 @@
959	999	goto unlock;
960	1000	}
961	1001
962		- if (time_after(jiffies,
	1002	+ /*
	1003	+ * Beacon filtering is only enabled with power save and then the
	1004	+ * stack should not check for beacon loss.
	1005	+ */
	1006	+ if (!((local->hw.flags & IEEE80211_HW_BEACON_FILTER) &&
	1007	+ (local->hw.conf.flags & IEEE80211_CONF_PS)) &&
	1008	+ time_after(jiffies,
963	1009	ifmgd->last_beacon + IEEE80211_MONITORING_INTERVAL)) {
964	1010	printk(KERN_DEBUG "%s: beacon loss from AP %pM "
965	1011	"- sending probe request\n",
...	...	@@ -1869,6 +1915,7 @@
1869	1915	ifmgd = &sdata->u.mgd;
1870	1916	INIT_WORK(&ifmgd->work, ieee80211_sta_work);
1871	1917	INIT_WORK(&ifmgd->chswitch_work, ieee80211_chswitch_work);
	1918	+ INIT_WORK(&ifmgd->beacon_loss_work, ieee80211_beacon_loss_work);
1872	1919	setup_timer(&ifmgd->timer, ieee80211_sta_timer,
1873	1920	(unsigned long) sdata);
1874	1921	setup_timer(&ifmgd->chswitch_timer, ieee80211_chswitch_timer,