mac80211: refactor SKB queue processing a bit

This is a very long loop body, move it into its own function
instead, keeping only the kcov and free outside in the loop
body.

Link: https://lore.kernel.org/r/20210517230754.6bc6cdd68570.I28a86ebdb19601ca1965c4dc654cc49fc1064efa@changeidSigned-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/iface.c

@@ -1318,13 +1318,130 @@ static void ieee80211_if_setup_no_queue(struct net_device *dev)
 	dev->priv_flags |= IFF_NO_QUEUE;
 }
 
+static void ieee80211_iface_process_skb(struct ieee80211_local *local,
+					struct ieee80211_sub_if_data *sdata,
+					struct sk_buff *skb)
+{
+	struct ieee80211_mgmt *mgmt = (void *)skb->data;
+
+	if (ieee80211_is_action(mgmt->frame_control) &&
+	    mgmt->u.action.category == WLAN_CATEGORY_BACK) {
+		struct sta_info *sta;
+		int len = skb->len;
+
+		mutex_lock(&local->sta_mtx);
+		sta = sta_info_get_bss(sdata, mgmt->sa);
+		if (sta) {
+			switch (mgmt->u.action.u.addba_req.action_code) {
+			case WLAN_ACTION_ADDBA_REQ:
+				ieee80211_process_addba_request(local, sta,
+								mgmt, len);
+				break;
+			case WLAN_ACTION_ADDBA_RESP:
+				ieee80211_process_addba_resp(local, sta,
+							     mgmt, len);
+				break;
+			case WLAN_ACTION_DELBA:
+				ieee80211_process_delba(sdata, sta,
+							mgmt, len);
+				break;
+			default:
+				WARN_ON(1);
+				break;
+			}
+		}
+		mutex_unlock(&local->sta_mtx);
+	} else if (ieee80211_is_action(mgmt->frame_control) &&
+		   mgmt->u.action.category == WLAN_CATEGORY_VHT) {
+		switch (mgmt->u.action.u.vht_group_notif.action_code) {
+		case WLAN_VHT_ACTION_OPMODE_NOTIF: {
+			struct ieee80211_rx_status *status;
+			enum nl80211_band band;
+			struct sta_info *sta;
+			u8 opmode;
+
+			status = IEEE80211_SKB_RXCB(skb);
+			band = status->band;
+			opmode = mgmt->u.action.u.vht_opmode_notif.operating_mode;
+
+			mutex_lock(&local->sta_mtx);
+			sta = sta_info_get_bss(sdata, mgmt->sa);
+
+			if (sta)
+				ieee80211_vht_handle_opmode(sdata, sta, opmode,
+							    band);
+
+			mutex_unlock(&local->sta_mtx);
+			break;
+		}
+		case WLAN_VHT_ACTION_GROUPID_MGMT:
+			ieee80211_process_mu_groups(sdata, mgmt);
+			break;
+		default:
+			WARN_ON(1);
+			break;
+		}
+	} else if (ieee80211_is_ext(mgmt->frame_control)) {
+		if (sdata->vif.type == NL80211_IFTYPE_STATION)
+			ieee80211_sta_rx_queued_ext(sdata, skb);
+		else
+			WARN_ON(1);
+	} else if (ieee80211_is_data_qos(mgmt->frame_control)) {
+		struct ieee80211_hdr *hdr = (void *)mgmt;
+		struct sta_info *sta;
+
+		/*
+		 * So the frame isn't mgmt, but frame_control
+		 * is at the right place anyway, of course, so
+		 * the if statement is correct.
+		 *
+		 * Warn if we have other data frame types here,
+		 * they must not get here.
+		 */
+		WARN_ON(hdr->frame_control &
+				cpu_to_le16(IEEE80211_STYPE_NULLFUNC));
+		WARN_ON(!(hdr->seq_ctrl &
+				cpu_to_le16(IEEE80211_SCTL_FRAG)));
+		/*
+		 * This was a fragment of a frame, received while
+		 * a block-ack session was active. That cannot be
+		 * right, so terminate the session.
+		 */
+		mutex_lock(&local->sta_mtx);
+		sta = sta_info_get_bss(sdata, mgmt->sa);
+		if (sta) {
+			u16 tid = ieee80211_get_tid(hdr);
+
+			__ieee80211_stop_rx_ba_session(
+				sta, tid, WLAN_BACK_RECIPIENT,
+				WLAN_REASON_QSTA_REQUIRE_SETUP,
+				true);
+		}
+		mutex_unlock(&local->sta_mtx);
+	} else switch (sdata->vif.type) {
+	case NL80211_IFTYPE_STATION:
+		ieee80211_sta_rx_queued_mgmt(sdata, skb);
+		break;
+	case NL80211_IFTYPE_ADHOC:
+		ieee80211_ibss_rx_queued_mgmt(sdata, skb);
+		break;
+	case NL80211_IFTYPE_MESH_POINT:
+		if (!ieee80211_vif_is_mesh(&sdata->vif))
+			break;
+		ieee80211_mesh_rx_queued_mgmt(sdata, skb);
+		break;
+	default:
+		WARN(1, "frame for unexpected interface type");
+		break;
+	}
+}
+
 static void ieee80211_iface_work(struct work_struct *work)
 {
 	struct ieee80211_sub_if_data *sdata =
 		container_of(work, struct ieee80211_sub_if_data, work);
 	struct ieee80211_local *local = sdata->local;
 	struct sk_buff *skb;
-	struct sta_info *sta;
 
 	if (!ieee80211_sdata_running(sdata))
 		return;
@@ -1337,116 +1454,9 @@ static void ieee80211_iface_work(struct work_struct *work)
 
 	/* first process frames */
 	while ((skb = skb_dequeue(&sdata->skb_queue))) {
-		struct ieee80211_mgmt *mgmt = (void *)skb->data;
-
 		kcov_remote_start_common(skb_get_kcov_handle(skb));
-		if (ieee80211_is_action(mgmt->frame_control) &&
-		    mgmt->u.action.category == WLAN_CATEGORY_BACK) {
-			int len = skb->len;
-
-			mutex_lock(&local->sta_mtx);
-			sta = sta_info_get_bss(sdata, mgmt->sa);
-			if (sta) {
-				switch (mgmt->u.action.u.addba_req.action_code) {
-				case WLAN_ACTION_ADDBA_REQ:
-					ieee80211_process_addba_request(
-							local, sta, mgmt, len);
-					break;
-				case WLAN_ACTION_ADDBA_RESP:
-					ieee80211_process_addba_resp(local, sta,
-								     mgmt, len);
-					break;
-				case WLAN_ACTION_DELBA:
-					ieee80211_process_delba(sdata, sta,
-								mgmt, len);
-					break;
-				default:
-					WARN_ON(1);
-					break;
-				}
-			}
-			mutex_unlock(&local->sta_mtx);
-		} else if (ieee80211_is_action(mgmt->frame_control) &&
-			   mgmt->u.action.category == WLAN_CATEGORY_VHT) {
-			switch (mgmt->u.action.u.vht_group_notif.action_code) {
-			case WLAN_VHT_ACTION_OPMODE_NOTIF: {
-				struct ieee80211_rx_status *status;
-				enum nl80211_band band;
-				u8 opmode;
-
-				status = IEEE80211_SKB_RXCB(skb);
-				band = status->band;
-				opmode = mgmt->u.action.u.vht_opmode_notif.operating_mode;
-
-				mutex_lock(&local->sta_mtx);
-				sta = sta_info_get_bss(sdata, mgmt->sa);
-
-				if (sta)
-					ieee80211_vht_handle_opmode(sdata, sta,
-								    opmode,
-								    band);
-
-				mutex_unlock(&local->sta_mtx);
-				break;
-			}
-			case WLAN_VHT_ACTION_GROUPID_MGMT:
-				ieee80211_process_mu_groups(sdata, mgmt);
-				break;
-			default:
-				WARN_ON(1);
-				break;
-			}
-		} else if (ieee80211_is_ext(mgmt->frame_control)) {
-			if (sdata->vif.type == NL80211_IFTYPE_STATION)
-				ieee80211_sta_rx_queued_ext(sdata, skb);
-			else
-				WARN_ON(1);
-		} else if (ieee80211_is_data_qos(mgmt->frame_control)) {
-			struct ieee80211_hdr *hdr = (void *)mgmt;
-			/*
-			 * So the frame isn't mgmt, but frame_control
-			 * is at the right place anyway, of course, so
-			 * the if statement is correct.
-			 *
-			 * Warn if we have other data frame types here,
-			 * they must not get here.
-			 */
-			WARN_ON(hdr->frame_control &
-					cpu_to_le16(IEEE80211_STYPE_NULLFUNC));
-			WARN_ON(!(hdr->seq_ctrl &
-					cpu_to_le16(IEEE80211_SCTL_FRAG)));
-			/*
-			 * This was a fragment of a frame, received while
-			 * a block-ack session was active. That cannot be
-			 * right, so terminate the session.
-			 */
-			mutex_lock(&local->sta_mtx);
-			sta = sta_info_get_bss(sdata, mgmt->sa);
-			if (sta) {
-				u16 tid = ieee80211_get_tid(hdr);
 
-				__ieee80211_stop_rx_ba_session(
-					sta, tid, WLAN_BACK_RECIPIENT,
-					WLAN_REASON_QSTA_REQUIRE_SETUP,
-					true);
-			}
-			mutex_unlock(&local->sta_mtx);
-		} else switch (sdata->vif.type) {
-		case NL80211_IFTYPE_STATION:
-			ieee80211_sta_rx_queued_mgmt(sdata, skb);
-			break;
-		case NL80211_IFTYPE_ADHOC:
-			ieee80211_ibss_rx_queued_mgmt(sdata, skb);
-			break;
-		case NL80211_IFTYPE_MESH_POINT:
-			if (!ieee80211_vif_is_mesh(&sdata->vif))
-				break;
-			ieee80211_mesh_rx_queued_mgmt(sdata, skb);
-			break;
-		default:
-			WARN(1, "frame for unexpected interface type");
-			break;
-		}
+		ieee80211_iface_process_skb(local, sdata, skb);
 
 		kfree_skb(skb);
 		kcov_remote_stop();