nl80211: allow multiple active scheduled scan requests

This patch implements the idea to have multiple scheduled scan requests
running concurrently. It mainly illustrates how to deal with the incoming
request from user-space in terms of backward compatibility. In order to
use multiple scheduled scans user-space needs to provide a flag attribute
NL80211_ATTR_SCHED_SCAN_MULTI to indicate support. If not the request is
treated as a legacy scan.

Drivers currently supporting scheduled scan are now indicating they support
a single scheduled scan request. This obsoletes WIPHY_FLAG_SUPPORTS_SCHED_SCAN.

Reviewed-by: Hante Meuleman <hante.meuleman@broadcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieter-paul.giesberts@broadcom.com>
Reviewed-by: Franky Lin <franky.lin@broadcom.com>
Signed-off-by: Arend van Spriel <arend.vanspriel@broadcom.com>
[clean up netlink destroy path to avoid allocations, code cleanups]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 17 insertions, 12 deletions

diff --git a/net/wireless/core.c b/net/wireless/core.c
index 4ea28de3a636..a3c0c48afb85 100644
--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -330,14 +330,16 @@ static void cfg80211_destroy_iface_wk(struct work_struct *work)
 static void cfg80211_sched_scan_stop_wk(struct work_struct *work)
 {
 	struct cfg80211_registered_device *rdev;
+	struct cfg80211_sched_scan_request *req, *tmp;
 
 	rdev = container_of(work, struct cfg80211_registered_device,
 			   sched_scan_stop_wk);
 
 	rtnl_lock();
-
-	__cfg80211_stop_sched_scan(rdev, false);
-
+	list_for_each_entry_safe(req, tmp, &rdev->sched_scan_req_list, list) {
+		if (req->nl_owner_dead)
+			cfg80211_stop_sched_scan_req(rdev, req, false);
+	}
 	rtnl_unlock();
 }
 
@@ -452,6 +454,7 @@ use_default_name:
 	spin_lock_init(&rdev->beacon_registrations_lock);
 	spin_lock_init(&rdev->bss_lock);
 	INIT_LIST_HEAD(&rdev->bss_list);
+	INIT_LIST_HEAD(&rdev->sched_scan_req_list);
 	INIT_WORK(&rdev->scan_done_wk, __cfg80211_scan_done);
 	INIT_WORK(&rdev->sched_scan_results_wk, __cfg80211_sched_scan_results);
 	INIT_LIST_HEAD(&rdev->mlme_unreg);
@@ -1028,7 +1031,7 @@ void __cfg80211_leave(struct cfg80211_registered_device *rdev,
 		      struct wireless_dev *wdev)
 {
 	struct net_device *dev = wdev->netdev;
-	struct cfg80211_sched_scan_request *sched_scan_req;
+	struct cfg80211_sched_scan_request *pos, *tmp;
 
 	ASSERT_RTNL();
 	ASSERT_WDEV_LOCK(wdev);
@@ -1039,9 +1042,11 @@ void __cfg80211_leave(struct cfg80211_registered_device *rdev,
 		break;
 	case NL80211_IFTYPE_P2P_CLIENT:
 	case NL80211_IFTYPE_STATION:
-		sched_scan_req = rtnl_dereference(rdev->sched_scan_req);
-		if (sched_scan_req && dev == sched_scan_req->dev)
-			__cfg80211_stop_sched_scan(rdev, false);
+		list_for_each_entry_safe(pos, tmp, &rdev->sched_scan_req_list,
+					 list) {
+			if (dev == pos->dev)
+				cfg80211_stop_sched_scan_req(rdev, pos, false);
+		}
 
 #ifdef CONFIG_CFG80211_WEXT
 		kfree(wdev->wext.ie);
@@ -1116,7 +1121,7 @@ static int cfg80211_netdev_notifier_call(struct notifier_block *nb,
 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 	struct wireless_dev *wdev = dev->ieee80211_ptr;
 	struct cfg80211_registered_device *rdev;
-	struct cfg80211_sched_scan_request *sched_scan_req;
+	struct cfg80211_sched_scan_request *pos, *tmp;
 
 	if (!wdev)
 		return NOTIFY_DONE;
@@ -1193,10 +1198,10 @@ static int cfg80211_netdev_notifier_call(struct notifier_block *nb,
 			___cfg80211_scan_done(rdev, false);
 		}
 
-		sched_scan_req = rtnl_dereference(rdev->sched_scan_req);
-		if (WARN_ON(sched_scan_req &&
-			    sched_scan_req->dev == wdev->netdev)) {
-			__cfg80211_stop_sched_scan(rdev, false);
+		list_for_each_entry_safe(pos, tmp,
+					 &rdev->sched_scan_req_list, list) {
+			if (WARN_ON(pos && pos->dev == wdev->netdev))
+				cfg80211_stop_sched_scan_req(rdev, pos, false);
 		}
 
 		rdev->opencount--;