qcacld-3.0: Cleanup blocked scan requests

The following memory leak issues of blocked scan requests
need to be addressed:

1. Add list for blocked scan requests

There could be multiple scan requests are blocked before related
callback can be executed. Currently there is only one pointer
for such requests. A list is added accordingly.

2. Cleanup blocked scan request when ifdown

Scheduled work for blocked scan might not be able to be executed
before ifdown. When the work is cancelled, related scan request is
not freed and will caused memory leak.

Call the relate callback when blocked scan work is cancelled to
cleanup the pending scan request.

Change-Id: Ifb5fc1b14a043ad67e4ba1d305ce4133b471188c
CRs-Fixed: 2166111

core/hdd/inc/wlan_hdd_main.h

@@ -1197,8 +1197,6 @@ struct hdd_adapter {
 
 	/* TODO Move this to sta Ctx */
 	struct wireless_dev wdev;
-	struct cfg80211_scan_request *request;
-	struct cfg80211_scan_request *vendor_request;
 
 	/** ops checks if Opportunistic Power Save is Enable or Not
 	 * ctw stores ctWindow value once we receive Opps command from
@@ -1333,6 +1331,8 @@ struct hdd_adapter {
 	struct delayed_work acs_pending_work;
 
 	struct work_struct scan_block_work;
+	qdf_list_t blocked_scan_request_q;
+	qdf_mutex_t blocked_scan_request_q_lock;
 #ifdef MSM_PLATFORM
 	unsigned long prev_rx_packets;
 	unsigned long prev_tx_packets;

core/hdd/src/wlan_hdd_main.c

@@ -618,10 +618,13 @@ static int __hdd_netdev_notifier_call(struct notifier_block *nb,
 				SCAN_NOT_IN_PROGRESS) {
 			wlan_abort_scan(hdd_ctx->hdd_pdev, INVAL_PDEV_ID,
 				adapter->session_id, INVALID_SCAN_ID, true);
-		} else {
-			cds_flush_work(&adapter->scan_block_work);
-			hdd_debug("Scan is not Pending from user");
 		}
+		cds_flush_work(&adapter->scan_block_work);
+		/* Need to clean up blocked scan request */
+		wlan_hdd_cfg80211_scan_block_cb(&adapter->scan_block_work);
+		qdf_list_destroy(&adapter->blocked_scan_request_q);
+		qdf_mutex_destroy(&adapter->blocked_scan_request_q_lock);
+		hdd_debug("Scan is not Pending from user");
 		/*
 		 * After NETDEV_GOING_DOWN, kernel calls hdd_stop.Irrespective
 		 * of return status of hdd_stop call, kernel resets the IFF_UP
@@ -4770,6 +4773,8 @@ struct hdd_adapter *hdd_open_adapter(struct hdd_context *hdd_ctx, uint8_t sessio
 	}
 
 	INIT_WORK(&adapter->scan_block_work, wlan_hdd_cfg80211_scan_block_cb);
+	qdf_list_create(&adapter->blocked_scan_request_q, WLAN_MAX_SCAN_COUNT);
+	qdf_mutex_create(&adapter->blocked_scan_request_q_lock);
 
 	if (QDF_STATUS_SUCCESS == status) {
 		/* Add it to the hdd's session list. */

core/hdd/src/wlan_hdd_scan.c

@@ -283,7 +283,8 @@ static void __wlan_hdd_cfg80211_scan_block_cb(struct work_struct *work)
 {
 	struct hdd_adapter *adapter;
 	struct cfg80211_scan_request *request;
-	struct hdd_context *hdd_ctx;
+	struct scan_req *blocked_scan_req;
+	qdf_list_node_t *node = NULL;
 
 	adapter = container_of(work, struct hdd_adapter, scan_block_work);
 	if (WLAN_HDD_ADAPTER_MAGIC != adapter->magic) {
@@ -291,28 +292,27 @@ static void __wlan_hdd_cfg80211_scan_block_cb(struct work_struct *work)
 		return;
 	}
 
-	hdd_ctx = WLAN_HDD_GET_CTX(adapter);
-	if (0 != wlan_hdd_validate_context(hdd_ctx))
-		return;
+	qdf_mutex_acquire(&adapter->blocked_scan_request_q_lock);
 
-	request = adapter->request;
-	if (request) {
+	while (!qdf_list_empty(&adapter->blocked_scan_request_q)) {
+		qdf_list_remove_front(&adapter->blocked_scan_request_q,
+				      &node);
+		blocked_scan_req = qdf_container_of(node, struct scan_req,
+						    node);
+		request = blocked_scan_req->scan_request;
 		request->n_ssids = 0;
 		request->n_channels = 0;
-
-		hdd_err("##In DFS Master mode. Scan aborted. Null result sent");
-		hdd_cfg80211_scan_done(adapter, request, true);
-		adapter->request = NULL;
+		if (blocked_scan_req->source == NL_SCAN) {
+			hdd_err("Scan aborted. Null result sent");
+			hdd_cfg80211_scan_done(adapter, request, true);
+		} else {
+			hdd_err("Vendor scan aborted. Null result sent");
+			hdd_vendor_scan_callback(adapter, request, true);
+		}
+		qdf_mem_free(blocked_scan_req);
 	}
-	request = adapter->vendor_request;
-	if (request) {
-		request->n_ssids = 0;
-		request->n_channels = 0;
 
-		hdd_err("In DFS Master mode. Scan aborted. Null result sent");
-		hdd_vendor_scan_callback(adapter, request, true);
-		adapter->vendor_request = NULL;
-	}
+	qdf_mutex_release(&adapter->blocked_scan_request_q_lock);
 }
 
 void wlan_hdd_cfg80211_scan_block_cb(struct work_struct *work)
@@ -387,6 +387,43 @@ static int wlan_hdd_update_scan_ies(struct hdd_adapter *adapter,
 	return 0;
 }
 
+static int
+wlan_hdd_enqueue_blocked_scan_request(struct net_device *dev,
+				      struct cfg80211_scan_request *request,
+				      uint8_t source)
+{
+	struct hdd_adapter *adapter = WLAN_HDD_GET_PRIV_PTR(dev);
+	struct scan_req *blocked_scan_req =
+		qdf_mem_malloc(sizeof(*blocked_scan_req));
+	int ret = 0;
+
+	if (!blocked_scan_req) {
+		hdd_err("Failed to allocate scan_req");
+		return -EINVAL;
+	}
+
+	blocked_scan_req->dev = dev;
+	blocked_scan_req->scan_request = request;
+	blocked_scan_req->source = source;
+	blocked_scan_req->scan_id = 0;
+
+	qdf_mutex_acquire(&adapter->blocked_scan_request_q_lock);
+	if (qdf_list_size(&adapter->blocked_scan_request_q) <
+		WLAN_MAX_SCAN_COUNT)
+		qdf_list_insert_back(&adapter->blocked_scan_request_q,
+				     &blocked_scan_req->node);
+	else
+		ret = -EINVAL;
+	qdf_mutex_release(&adapter->blocked_scan_request_q_lock);
+
+	if (ret) {
+		hdd_err("Maximum number of block scan request reached!");
+		qdf_mem_free(blocked_scan_req);
+	}
+
+	return ret;
+}
+
 /* Define short name to use in cds_trigger_recovery */
 #define SCAN_FAILURE QDF_SCAN_ATTEMPT_FAILURES
 
@@ -452,10 +489,8 @@ static int __wlan_hdd_cfg80211_scan(struct wiphy *wiphy,
 						conn_info.connState) &&
 	    (!hdd_ctx->config->enable_connected_scan)) {
 		hdd_info("enable_connected_scan is false, Aborting scan");
-		if (NL_SCAN == source)
-			adapter->request = request;
-		else
-			adapter->vendor_request = request;
+		if (wlan_hdd_enqueue_blocked_scan_request(dev, request, source))
+			return -EAGAIN;
 		schedule_work(&adapter->scan_block_work);
 		return 0;
 	}
@@ -505,11 +540,9 @@ static int __wlan_hdd_cfg80211_scan(struct wiphy *wiphy,
 			 * startup.
 			 */
 			hdd_err("##In DFS Master mode. Scan aborted");
-			if (NL_SCAN == source)
-				adapter->request = request;
-			else
-				adapter->vendor_request = request;
-
+			if (wlan_hdd_enqueue_blocked_scan_request(dev, request,
+								  source))
+				return -EAGAIN;
 			schedule_work(&adapter->scan_block_work);
 			return 0;
 		}
@@ -563,10 +596,8 @@ static int __wlan_hdd_cfg80211_scan(struct wiphy *wiphy,
 	if (adapter->device_mode == QDF_SAP_MODE &&
 	   wlan_hdd_sap_skip_scan_check(hdd_ctx, request)) {
 		hdd_debug("sap scan skipped");
-		if (NL_SCAN == source)
-			adapter->request = request;
-		else
-			adapter->vendor_request = request;
+		if (wlan_hdd_enqueue_blocked_scan_request(dev, request, source))
+			return -EAGAIN;
 		schedule_work(&adapter->scan_block_work);
 		return 0;
 	}