1 files changed, 320 insertions, 125 deletions

diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 132938b073dc..3610c11286bc 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -17,6 +17,8 @@
 #include <linux/if_arp.h>
 #include <linux/etherdevice.h>
 #include <linux/rtnetlink.h>
+#include <linux/pm_qos_params.h>
+#include <linux/crc32.h>
 #include <net/mac80211.h>
 #include <asm/unaligned.h>
 
@@ -80,6 +82,89 @@ static int ieee80211_compatible_rates(struct ieee80211_bss *bss,
 	return count;
 }
 
+/*
+ * ieee80211_enable_ht should be called only after the operating band
+ * has been determined as ht configuration depends on the hw's
+ * HT abilities for a specific band.
+ */
+static u32 ieee80211_enable_ht(struct ieee80211_sub_if_data *sdata,
+			       struct ieee80211_ht_info *hti,
+			       u16 ap_ht_cap_flags)
+{
+	struct ieee80211_local *local = sdata->local;
+	struct ieee80211_supported_band *sband;
+	struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
+	struct ieee80211_bss_ht_conf ht;
+	struct sta_info *sta;
+	u32 changed = 0;
+	bool enable_ht = true, ht_changed;
+	enum nl80211_channel_type channel_type = NL80211_CHAN_NO_HT;
+
+	sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
+
+	memset(&ht, 0, sizeof(ht));
+
+	/* HT is not supported */
+	if (!sband->ht_cap.ht_supported)
+		enable_ht = false;
+
+	/* check that channel matches the right operating channel */
+	if (local->hw.conf.channel->center_freq !=
+	    ieee80211_channel_to_frequency(hti->control_chan))
+		enable_ht = false;
+
+	if (enable_ht) {
+		channel_type = NL80211_CHAN_HT20;
+
+		if (!(ap_ht_cap_flags & IEEE80211_HT_CAP_40MHZ_INTOLERANT) &&
+		    (sband->ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) &&
+		    (hti->ht_param & IEEE80211_HT_PARAM_CHAN_WIDTH_ANY)) {
+			switch(hti->ht_param & IEEE80211_HT_PARAM_CHA_SEC_OFFSET) {
+			case IEEE80211_HT_PARAM_CHA_SEC_ABOVE:
+				channel_type = NL80211_CHAN_HT40PLUS;
+				break;
+			case IEEE80211_HT_PARAM_CHA_SEC_BELOW:
+				channel_type = NL80211_CHAN_HT40MINUS;
+				break;
+			}
+		}
+	}
+
+	ht_changed = conf_is_ht(&local->hw.conf) != enable_ht ||
+		     channel_type != local->hw.conf.channel_type;
+
+	local->oper_channel_type = channel_type;
+
+	if (ht_changed) {
+                /* channel_type change automatically detected */
+		ieee80211_hw_config(local, 0);
+
+		rcu_read_lock();
+
+		sta = sta_info_get(local, ifmgd->bssid);
+		if (sta)
+			rate_control_rate_update(local, sband, sta,
+						 IEEE80211_RC_HT_CHANGED);
+
+		rcu_read_unlock();
+
+        }
+
+	/* disable HT */
+	if (!enable_ht)
+		return 0;
+
+	ht.operation_mode = le16_to_cpu(hti->operation_mode);
+
+	/* if bss configuration changed store the new one */
+	if (memcmp(&sdata->vif.bss_conf.ht, &ht, sizeof(ht))) {
+		changed |= BSS_CHANGED_HT;
+		sdata->vif.bss_conf.ht = ht;
+	}
+
+	return changed;
+}
+
 /* frame sending functions */
 
 static void ieee80211_send_assoc(struct ieee80211_sub_if_data *sdata)
@@ -325,6 +410,10 @@ static void ieee80211_send_deauth_disassoc(struct ieee80211_sub_if_data *sdata,
 	/* u.deauth.reason_code == u.disassoc.reason_code */
 	mgmt->u.deauth.reason_code = cpu_to_le16(reason);
 
+	if (stype == IEEE80211_STYPE_DEAUTH)
+		cfg80211_send_deauth(sdata->dev, (u8 *) mgmt, skb->len);
+	else
+		cfg80211_send_disassoc(sdata->dev, (u8 *) mgmt, skb->len);
 	ieee80211_tx_skb(sdata, skb, ifmgd->flags & IEEE80211_STA_MFP_ENABLED);
 }
 
@@ -359,6 +448,166 @@ void ieee80211_send_pspoll(struct ieee80211_local *local,
 	ieee80211_tx_skb(sdata, skb, 0);
 }
 
+void ieee80211_send_nullfunc(struct ieee80211_local *local,
+			     struct ieee80211_sub_if_data *sdata,
+			     int powersave)
+{
+	struct sk_buff *skb;
+	struct ieee80211_hdr *nullfunc;
+	__le16 fc;
+
+	if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_STATION))
+		return;
+
+	skb = dev_alloc_skb(local->hw.extra_tx_headroom + 24);
+	if (!skb) {
+		printk(KERN_DEBUG "%s: failed to allocate buffer for nullfunc "
+		       "frame\n", sdata->dev->name);
+		return;
+	}
+	skb_reserve(skb, local->hw.extra_tx_headroom);
+
+	nullfunc = (struct ieee80211_hdr *) skb_put(skb, 24);
+	memset(nullfunc, 0, 24);
+	fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_NULLFUNC |
+			 IEEE80211_FCTL_TODS);
+	if (powersave)
+		fc |= cpu_to_le16(IEEE80211_FCTL_PM);
+	nullfunc->frame_control = fc;
+	memcpy(nullfunc->addr1, sdata->u.mgd.bssid, ETH_ALEN);
+	memcpy(nullfunc->addr2, sdata->dev->dev_addr, ETH_ALEN);
+	memcpy(nullfunc->addr3, sdata->u.mgd.bssid, ETH_ALEN);
+
+	ieee80211_tx_skb(sdata, skb, 0);
+}
+
+/* powersave */
+static void ieee80211_enable_ps(struct ieee80211_local *local,
+				struct ieee80211_sub_if_data *sdata)
+{
+	struct ieee80211_conf *conf = &local->hw.conf;
+
+	if (conf->dynamic_ps_timeout > 0 &&
+	    !(local->hw.flags & IEEE80211_HW_SUPPORTS_DYNAMIC_PS)) {
+		mod_timer(&local->dynamic_ps_timer, jiffies +
+			  msecs_to_jiffies(conf->dynamic_ps_timeout));
+	} else {
+		if (local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK)
+			ieee80211_send_nullfunc(local, sdata, 1);
+		conf->flags |= IEEE80211_CONF_PS;
+		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
+	}
+}
+
+static void ieee80211_change_ps(struct ieee80211_local *local)
+{
+	struct ieee80211_conf *conf = &local->hw.conf;
+
+	if (local->ps_sdata) {
+		if (!(local->ps_sdata->u.mgd.flags & IEEE80211_STA_ASSOCIATED))
+			return;
+
+		ieee80211_enable_ps(local, local->ps_sdata);
+	} else if (conf->flags & IEEE80211_CONF_PS) {
+		conf->flags &= ~IEEE80211_CONF_PS;
+		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
+		del_timer_sync(&local->dynamic_ps_timer);
+		cancel_work_sync(&local->dynamic_ps_enable_work);
+	}
+}
+
+/* need to hold RTNL or interface lock */
+void ieee80211_recalc_ps(struct ieee80211_local *local, s32 latency)
+{
+	struct ieee80211_sub_if_data *sdata, *found = NULL;
+	int count = 0;
+
+	if (!(local->hw.flags & IEEE80211_HW_SUPPORTS_PS)) {
+		local->ps_sdata = NULL;
+		return;
+	}
+
+	list_for_each_entry(sdata, &local->interfaces, list) {
+		if (!netif_running(sdata->dev))
+			continue;
+		if (sdata->vif.type != NL80211_IFTYPE_STATION)
+			continue;
+		found = sdata;
+		count++;
+	}
+
+	if (count == 1 && found->u.mgd.powersave) {
+		s32 beaconint_us;
+
+		if (latency < 0)
+			latency = pm_qos_requirement(PM_QOS_NETWORK_LATENCY);
+
+		beaconint_us = ieee80211_tu_to_usec(
+					found->vif.bss_conf.beacon_int);
+
+		if (beaconint_us > latency) {
+			local->ps_sdata = NULL;
+		} else {
+			u8 dtimper = found->vif.bss_conf.dtim_period;
+			int maxslp = 1;
+
+			if (dtimper > 1)
+				maxslp = min_t(int, dtimper,
+						    latency / beaconint_us);
+
+			local->hw.conf.max_sleep_interval = maxslp;
+			local->ps_sdata = found;
+		}
+	} else {
+		local->ps_sdata = NULL;
+	}
+
+	ieee80211_change_ps(local);
+}
+
+void ieee80211_dynamic_ps_disable_work(struct work_struct *work)
+{
+	struct ieee80211_local *local =
+		container_of(work, struct ieee80211_local,
+			     dynamic_ps_disable_work);
+
+	if (local->hw.conf.flags & IEEE80211_CONF_PS) {
+		local->hw.conf.flags &= ~IEEE80211_CONF_PS;
+		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
+	}
+
+	ieee80211_wake_queues_by_reason(&local->hw,
+					IEEE80211_QUEUE_STOP_REASON_PS);
+}
+
+void ieee80211_dynamic_ps_enable_work(struct work_struct *work)
+{
+	struct ieee80211_local *local =
+		container_of(work, struct ieee80211_local,
+			     dynamic_ps_enable_work);
+	struct ieee80211_sub_if_data *sdata = local->ps_sdata;
+
+	/* can only happen when PS was just disabled anyway */
+	if (!sdata)
+		return;
+
+	if (local->hw.conf.flags & IEEE80211_CONF_PS)
+		return;
+
+	if (local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK)
+		ieee80211_send_nullfunc(local, sdata, 1);
+
+	local->hw.conf.flags |= IEEE80211_CONF_PS;
+	ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
+}
+
+void ieee80211_dynamic_ps_timer(unsigned long data)
+{
+	struct ieee80211_local *local = (void *) data;
+
+	queue_work(local->hw.workqueue, &local->dynamic_ps_enable_work);
+}
+
 /* MLME */
 static void ieee80211_sta_wmm_params(struct ieee80211_local *local,
 				     struct ieee80211_if_managed *ifmgd,
@@ -435,30 +684,6 @@ static void ieee80211_sta_wmm_params(struct ieee80211_local *local,
 	}
 }
 
-static bool ieee80211_check_tim(struct ieee802_11_elems *elems, u16 aid)
-{
-	u8 mask;
-	u8 index, indexn1, indexn2;
-	struct ieee80211_tim_ie *tim = (struct ieee80211_tim_ie *) elems->tim;
-
-	if (unlikely(!tim || elems->tim_len < 4))
-		return false;
-
-	aid &= 0x3fff;
-	index = aid / 8;
-	mask  = 1 << (aid & 7);
-
-	indexn1 = tim->bitmap_ctrl & 0xfe;
-	indexn2 = elems->tim_len + indexn1 - 4;
-
-	if (index < indexn1 || index > indexn2)
-		return false;
-
-	index -= indexn1;
-
-	return !!(tim->virtual_map[index] & mask);
-}
-
 static u32 ieee80211_handle_bss_capability(struct ieee80211_sub_if_data *sdata,
 					   u16 capab, bool erp_valid, u8 erp)
 {
@@ -634,18 +859,11 @@ static void ieee80211_set_associated(struct ieee80211_sub_if_data *sdata,
 	bss_info_changed |= BSS_CHANGED_BASIC_RATES;
 	ieee80211_bss_info_change_notify(sdata, bss_info_changed);
 
-	if (local->powersave) {
-		if (!(local->hw.flags & IEEE80211_HW_SUPPORTS_DYNAMIC_PS) &&
-		    local->hw.conf.dynamic_ps_timeout > 0) {
-			mod_timer(&local->dynamic_ps_timer, jiffies +
-				  msecs_to_jiffies(
-					local->hw.conf.dynamic_ps_timeout));
-		} else {
-			if (local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK)
-				ieee80211_send_nullfunc(local, sdata, 1);
-			conf->flags |= IEEE80211_CONF_PS;
-			ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
-		}
+	/* will be same as sdata */
+	if (local->ps_sdata) {
+		mutex_lock(&local->iflist_mtx);
+		ieee80211_recalc_ps(local, -1);
+		mutex_unlock(&local->iflist_mtx);
 	}
 
 	netif_tx_start_all_queues(sdata->dev);
@@ -714,7 +932,7 @@ static void ieee80211_authenticate(struct ieee80211_sub_if_data *sdata)
 		       " timed out\n",
 		       sdata->dev->name, ifmgd->bssid);
 		ifmgd->state = IEEE80211_STA_MLME_DISABLED;
-		ieee80211_sta_send_apinfo(sdata);
+		cfg80211_send_auth_timeout(sdata->dev, ifmgd->bssid);
 		ieee80211_rx_bss_remove(sdata, ifmgd->bssid,
 				sdata->local->hw.conf.channel->center_freq,
 				ifmgd->ssid, ifmgd->ssid_len);
@@ -897,7 +1115,7 @@ static void ieee80211_associate(struct ieee80211_sub_if_data *sdata)
 		       " timed out\n",
 		       sdata->dev->name, ifmgd->bssid);
 		ifmgd->state = IEEE80211_STA_MLME_DISABLED;
-		ieee80211_sta_send_apinfo(sdata);
+		cfg80211_send_assoc_timeout(sdata->dev, ifmgd->bssid);
 		ieee80211_rx_bss_remove(sdata, ifmgd->bssid,
 				sdata->local->hw.conf.channel->center_freq,
 				ifmgd->ssid, ifmgd->ssid_len);
@@ -1187,7 +1405,7 @@ static void ieee80211_rx_mgmt_deauth(struct ieee80211_sub_if_data *sdata,
 
 	ieee80211_set_disassoc(sdata, true, false, 0);
 	ifmgd->flags &= ~IEEE80211_STA_AUTHENTICATED;
-	cfg80211_send_rx_deauth(sdata->dev, (u8 *) mgmt, len);
+	cfg80211_send_deauth(sdata->dev, (u8 *) mgmt, len);
 }
 
 
@@ -1218,7 +1436,7 @@ static void ieee80211_rx_mgmt_disassoc(struct ieee80211_sub_if_data *sdata,
 	}
 
 	ieee80211_set_disassoc(sdata, false, false, reason_code);
-	cfg80211_send_rx_disassoc(sdata->dev, (u8 *) mgmt, len);
+	cfg80211_send_disassoc(sdata->dev, (u8 *) mgmt, len);
 }
 
 
@@ -1287,6 +1505,11 @@ static void ieee80211_rx_mgmt_assoc_resp(struct ieee80211_sub_if_data *sdata,
 		 * association next time. This works around some broken APs
 		 * which do not correctly reject reassociation requests. */
 		ifmgd->flags &= ~IEEE80211_STA_PREV_BSSID_SET;
+		cfg80211_send_rx_assoc(sdata->dev, (u8 *) mgmt, len);
+		if (ifmgd->flags & IEEE80211_STA_EXT_SME) {
+			/* Wait for SME to decide what to do next */
+			ifmgd->state = IEEE80211_STA_MLME_DISABLED;
+		}
 		return;
 	}
 
@@ -1518,46 +1741,74 @@ static void ieee80211_rx_mgmt_probe_resp(struct ieee80211_sub_if_data *sdata,
 		ifmgd->flags &= ~IEEE80211_STA_PROBEREQ_POLL;
 }
 
+/*
+ * This is the canonical list of information elements we care about,
+ * the filter code also gives us all changes to the Microsoft OUI
+ * (00:50:F2) vendor IE which is used for WMM which we need to track.
+ *
+ * We implement beacon filtering in software since that means we can
+ * avoid processing the frame here and in cfg80211, and userspace
+ * will not be able to tell whether the hardware supports it or not.
+ *
+ * XXX: This list needs to be dynamic -- userspace needs to be able to
+ *	add items it requires. It also needs to be able to tell us to
+ *	look out for other vendor IEs.
+ */
+static const u64 care_about_ies =
+	(1ULL << WLAN_EID_COUNTRY) |
+	(1ULL << WLAN_EID_ERP_INFO) |
+	(1ULL << WLAN_EID_CHANNEL_SWITCH) |
+	(1ULL << WLAN_EID_PWR_CONSTRAINT) |
+	(1ULL << WLAN_EID_HT_CAPABILITY) |
+	(1ULL << WLAN_EID_HT_INFORMATION);
+
 static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
 				     struct ieee80211_mgmt *mgmt,
 				     size_t len,
 				     struct ieee80211_rx_status *rx_status)
 {
-	struct ieee80211_if_managed *ifmgd;
+	struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
 	size_t baselen;
 	struct ieee802_11_elems elems;
 	struct ieee80211_local *local = sdata->local;
 	u32 changed = 0;
-	bool erp_valid, directed_tim;
+	bool erp_valid, directed_tim = false;
 	u8 erp_value = 0;
+	u32 ncrc;
 
 	/* Process beacon from the current BSS */
 	baselen = (u8 *) mgmt->u.beacon.variable - (u8 *) mgmt;
 	if (baselen > len)
 		return;
 
-	ieee802_11_parse_elems(mgmt->u.beacon.variable, len - baselen, &elems);
-
-	ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, true);
-
-	if (sdata->vif.type != NL80211_IFTYPE_STATION)
+	if (rx_status->freq != local->hw.conf.channel->center_freq)
 		return;
 
-	ifmgd = &sdata->u.mgd;
-
 	if (!(ifmgd->flags & IEEE80211_STA_ASSOCIATED) ||
 	    memcmp(ifmgd->bssid, mgmt->bssid, ETH_ALEN) != 0)
 		return;
 
-	if (rx_status->freq != local->hw.conf.channel->center_freq)
+	ncrc = crc32_be(0, (void *)&mgmt->u.beacon.beacon_int, 4);
+	ncrc = ieee802_11_parse_elems_crc(mgmt->u.beacon.variable,
+					  len - baselen, &elems,
+					  care_about_ies, ncrc);
+
+	if (local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK)
+		directed_tim = ieee80211_check_tim(elems.tim, elems.tim_len,
+						   ifmgd->aid);
+
+	ncrc = crc32_be(ncrc, (void *)&directed_tim, sizeof(directed_tim));
+
+	if (ncrc == ifmgd->beacon_crc)
 		return;
+	ifmgd->beacon_crc = ncrc;
+
+	ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, true);
 
 	ieee80211_sta_wmm_params(local, ifmgd, elems.wmm_param,
 				 elems.wmm_param_len);
 
 	if (local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK) {
-		directed_tim = ieee80211_check_tim(&elems, ifmgd->aid);
-
 		if (directed_tim) {
 			if (local->hw.conf.dynamic_ps_timeout > 0) {
 				local->hw.conf.flags &= ~IEEE80211_CONF_PS;
@@ -1930,6 +2181,7 @@ static void ieee80211_restart_sta_timer(struct ieee80211_sub_if_data *sdata)
 void ieee80211_sta_setup_sdata(struct ieee80211_sub_if_data *sdata)
 {
 	struct ieee80211_if_managed *ifmgd;
+	u32 hw_flags;
 
 	ifmgd = &sdata->u.mgd;
 	INIT_WORK(&ifmgd->work, ieee80211_sta_work);
@@ -1949,6 +2201,13 @@ void ieee80211_sta_setup_sdata(struct ieee80211_sub_if_data *sdata)
 		IEEE80211_STA_AUTO_CHANNEL_SEL;
 	if (sdata->local->hw.queues >= 4)
 		ifmgd->flags |= IEEE80211_STA_WMM_ENABLED;
+
+	hw_flags = sdata->local->hw.flags;
+
+	if (hw_flags & IEEE80211_HW_SUPPORTS_PS) {
+		ifmgd->powersave = CONFIG_MAC80211_DEFAULT_PS_VALUE;
+		sdata->local->hw.conf.dynamic_ps_timeout = 500;
+	}
 }
 
 /* configuration hooks */
@@ -2068,9 +2327,6 @@ int ieee80211_sta_deauthenticate(struct ieee80211_sub_if_data *sdata, u16 reason
 	printk(KERN_DEBUG "%s: deauthenticating by local choice (reason=%d)\n",
 	       sdata->dev->name, reason);
 
-	if (sdata->vif.type != NL80211_IFTYPE_STATION)
-		return -EINVAL;
-
 	ieee80211_set_disassoc(sdata, true, true, reason);
 	return 0;
 }
@@ -2082,9 +2338,6 @@ int ieee80211_sta_disassociate(struct ieee80211_sub_if_data *sdata, u16 reason)
 	printk(KERN_DEBUG "%s: disassociating by local choice (reason=%d)\n",
 	       sdata->dev->name, reason);
 
-	if (sdata->vif.type != NL80211_IFTYPE_STATION)
-		return -EINVAL;
-
 	if (!(ifmgd->flags & IEEE80211_STA_ASSOCIATED))
 		return -ENOLINK;
 
@@ -2104,75 +2357,17 @@ void ieee80211_mlme_notify_scan_completed(struct ieee80211_local *local)
 	rcu_read_unlock();
 }
 
-void ieee80211_dynamic_ps_disable_work(struct work_struct *work)
+int ieee80211_max_network_latency(struct notifier_block *nb,
+				  unsigned long data, void *dummy)
 {
+	s32 latency_usec = (s32) data;
 	struct ieee80211_local *local =
-		container_of(work, struct ieee80211_local,
-			     dynamic_ps_disable_work);
+		container_of(nb, struct ieee80211_local,
+			     network_latency_notifier);
 
-	if (local->hw.conf.flags & IEEE80211_CONF_PS) {
-		local->hw.conf.flags &= ~IEEE80211_CONF_PS;
-		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
-	}
-
-	ieee80211_wake_queues_by_reason(&local->hw,
-					IEEE80211_QUEUE_STOP_REASON_PS);
-}
-
-void ieee80211_dynamic_ps_enable_work(struct work_struct *work)
-{
-	struct ieee80211_local *local =
-		container_of(work, struct ieee80211_local,
-			     dynamic_ps_enable_work);
-	/* XXX: using scan_sdata is completely broken! */
-	struct ieee80211_sub_if_data *sdata = local->scan_sdata;
-
-	if (local->hw.conf.flags & IEEE80211_CONF_PS)
-		return;
-
-	if (local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK && sdata)
-		ieee80211_send_nullfunc(local, sdata, 1);
-
-	local->hw.conf.flags |= IEEE80211_CONF_PS;
-	ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
-}
+	mutex_lock(&local->iflist_mtx);
+	ieee80211_recalc_ps(local, latency_usec);
+	mutex_unlock(&local->iflist_mtx);
 
-void ieee80211_dynamic_ps_timer(unsigned long data)
-{
-	struct ieee80211_local *local = (void *) data;
-
-	queue_work(local->hw.workqueue, &local->dynamic_ps_enable_work);
-}
-
-void ieee80211_send_nullfunc(struct ieee80211_local *local,
-			     struct ieee80211_sub_if_data *sdata,
-			     int powersave)
-{
-	struct sk_buff *skb;
-	struct ieee80211_hdr *nullfunc;
-	__le16 fc;
-
-	if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_STATION))
-		return;
-
-	skb = dev_alloc_skb(local->hw.extra_tx_headroom + 24);
-	if (!skb) {
-		printk(KERN_DEBUG "%s: failed to allocate buffer for nullfunc "
-		       "frame\n", sdata->dev->name);
-		return;
-	}
-	skb_reserve(skb, local->hw.extra_tx_headroom);
-
-	nullfunc = (struct ieee80211_hdr *) skb_put(skb, 24);
-	memset(nullfunc, 0, 24);
-	fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_NULLFUNC |
-			 IEEE80211_FCTL_TODS);
-	if (powersave)
-		fc |= cpu_to_le16(IEEE80211_FCTL_PM);
-	nullfunc->frame_control = fc;
-	memcpy(nullfunc->addr1, sdata->u.mgd.bssid, ETH_ALEN);
-	memcpy(nullfunc->addr2, sdata->dev->dev_addr, ETH_ALEN);
-	memcpy(nullfunc->addr3, sdata->u.mgd.bssid, ETH_ALEN);
-
-	ieee80211_tx_skb(sdata, skb, 0);
+	return 0;
 }