mac80211: dont call cfg80211 from ieee80211_send_deauth_disassoc

Instead of calling cfg80211 in ieee80211_send_deauth_disassoc()
pass out the frame and call it from the caller. That saves the
SKB allocation if we don't actually want to send the frame and
enables us to make the ordering smarter in the future.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

net/mac80211/mlme.c

@@ -88,6 +88,8 @@ MODULE_PARM_DESC(probe_wait_ms,
 #define TMR_RUNNING_TIMER	0
 #define TMR_RUNNING_CHANSW	1
 
+#define DEAUTH_DISASSOC_LEN	(24 /* hdr */ + 2 /* reason */)
+
 /*
  * All cfg80211 functions have to be called outside a locked
  * section so that they can acquire a lock themselves... This
@@ -613,47 +615,41 @@ static void ieee80211_send_assoc(struct ieee80211_sub_if_data *sdata)
 
 static void ieee80211_send_deauth_disassoc(struct ieee80211_sub_if_data *sdata,
 					   const u8 *bssid, u16 stype,
-					   u16 reason, bool cfg80211_locked,
-					   bool send_frame)
+					   u16 reason, bool send_frame,
+					   u8 *frame_buf)
 {
 	struct ieee80211_local *local = sdata->local;
 	struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
 	struct sk_buff *skb;
-	struct ieee80211_mgmt *mgmt;
-
-	skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*mgmt));
-	if (!skb)
-		return;
+	struct ieee80211_mgmt *mgmt = (void *)frame_buf;
 
-	skb_reserve(skb, local->hw.extra_tx_headroom);
-
-	mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
-	memset(mgmt, 0, 24);
+	/* build frame */
+	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | stype);
+	mgmt->duration = 0; /* initialize only */
+	mgmt->seq_ctrl = 0; /* initialize only */
 	memcpy(mgmt->da, bssid, ETH_ALEN);
 	memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
 	memcpy(mgmt->bssid, bssid, ETH_ALEN);
-	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | stype);
-	skb_put(skb, 2);
 	/* u.deauth.reason_code == u.disassoc.reason_code */
 	mgmt->u.deauth.reason_code = cpu_to_le16(reason);
 
-	if (stype == IEEE80211_STYPE_DEAUTH)
-		if (cfg80211_locked)
-			__cfg80211_send_deauth(sdata->dev, (u8 *)mgmt, skb->len);
-		else
-			cfg80211_send_deauth(sdata->dev, (u8 *)mgmt, skb->len);
-	else
-		if (cfg80211_locked)
-			__cfg80211_send_disassoc(sdata->dev, (u8 *)mgmt, skb->len);
-		else
-			cfg80211_send_disassoc(sdata->dev, (u8 *)mgmt, skb->len);
-	if (!(ifmgd->flags & IEEE80211_STA_MFP_ENABLED))
-		IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
+	if (send_frame) {
+		skb = dev_alloc_skb(local->hw.extra_tx_headroom +
+				    DEAUTH_DISASSOC_LEN);
+		if (!skb)
+			return;
 
-	if (send_frame)
+		skb_reserve(skb, local->hw.extra_tx_headroom);
+
+		/* copy in frame */
+		memcpy(skb_put(skb, DEAUTH_DISASSOC_LEN),
+		       mgmt, DEAUTH_DISASSOC_LEN);
+
+		if (!(ifmgd->flags & IEEE80211_STA_MFP_ENABLED))
+			IEEE80211_SKB_CB(skb)->flags |=
+				IEEE80211_TX_INTFL_DONT_ENCRYPT;
 		ieee80211_tx_skb(sdata, skb);
-	else
-		kfree_skb(skb);
+	}
 }
 
 void ieee80211_send_pspoll(struct ieee80211_local *local,
@@ -1675,6 +1671,7 @@ static void __ieee80211_connection_loss(struct ieee80211_sub_if_data *sdata)
 	struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
 	struct ieee80211_local *local = sdata->local;
 	u8 bssid[ETH_ALEN];
+	u8 frame_buf[DEAUTH_DISASSOC_LEN];
 
 	mutex_lock(&ifmgd->mtx);
 	if (!ifmgd->associated) {
@@ -1697,7 +1694,8 @@ static void __ieee80211_connection_loss(struct ieee80211_sub_if_data *sdata)
 	ieee80211_send_deauth_disassoc(sdata, bssid,
 				       IEEE80211_STYPE_DEAUTH,
 				       WLAN_REASON_DISASSOC_DUE_TO_INACTIVITY,
-				       false, true);
+				       false, frame_buf);
+	cfg80211_send_deauth(sdata->dev, frame_buf, DEAUTH_DISASSOC_LEN);
 
 	mutex_lock(&local->mtx);
 	ieee80211_recalc_idle(local);
@@ -2696,6 +2694,7 @@ static void ieee80211_sta_connection_lost(struct ieee80211_sub_if_data *sdata,
 {
 	struct ieee80211_local *local = sdata->local;
 	struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
+	u8 frame_buf[DEAUTH_DISASSOC_LEN];
 
 	ifmgd->flags &= ~(IEEE80211_STA_CONNECTION_POLL |
 			  IEEE80211_STA_BEACON_POLL);
@@ -2708,7 +2707,8 @@ static void ieee80211_sta_connection_lost(struct ieee80211_sub_if_data *sdata,
 	 */
 	ieee80211_send_deauth_disassoc(sdata, bssid,
 				       IEEE80211_STYPE_DEAUTH,
-				       reason, false, true);
+				       reason, false, frame_buf);
+	cfg80211_send_deauth(sdata->dev, frame_buf, DEAUTH_DISASSOC_LEN);
 
 	mutex_lock(&local->mtx);
 	ieee80211_recalc_idle(local);
@@ -3444,6 +3444,7 @@ int ieee80211_mgd_deauth(struct ieee80211_sub_if_data *sdata,
 {
 	struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
 	bool assoc_bss = false;
+	u8 frame_buf[DEAUTH_DISASSOC_LEN];
 
 	mutex_lock(&ifmgd->mtx);
 
@@ -3463,7 +3464,8 @@ int ieee80211_mgd_deauth(struct ieee80211_sub_if_data *sdata,
 
 	ieee80211_send_deauth_disassoc(sdata, req->bssid,
 				       IEEE80211_STYPE_DEAUTH,
-				       req->reason_code, true, true);
+				       req->reason_code, true, frame_buf);
+	__cfg80211_send_deauth(sdata->dev, frame_buf, DEAUTH_DISASSOC_LEN);
 	if (assoc_bss)
 		sta_info_flush(sdata->local, sdata);
 
@@ -3479,6 +3481,7 @@ int ieee80211_mgd_disassoc(struct ieee80211_sub_if_data *sdata,
 {
 	struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
 	u8 bssid[ETH_ALEN];
+	u8 frame_buf[DEAUTH_DISASSOC_LEN];
 
 	mutex_lock(&ifmgd->mtx);
 
@@ -3502,8 +3505,10 @@ int ieee80211_mgd_disassoc(struct ieee80211_sub_if_data *sdata,
 	mutex_unlock(&ifmgd->mtx);
 
 	ieee80211_send_deauth_disassoc(sdata, req->bss->bssid,
-			IEEE80211_STYPE_DISASSOC, req->reason_code,
-			true, !req->local_state_change);
+				       IEEE80211_STYPE_DISASSOC,
+				       req->reason_code,
+				       !req->local_state_change, frame_buf);
+	__cfg80211_send_disassoc(sdata->dev, frame_buf, DEAUTH_DISASSOC_LEN);
 	sta_info_flush(sdata->local, sdata);
 
 	mutex_lock(&sdata->local->mtx);