nl80211: Stop scheduled scan if netlink client disappears

An attribute NL80211_ATTR_SOCKET_OWNER can be set by the scan initiator.
If present, the attribute will cause the scan to be stopped if the client
dies.

Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

3 files changed, 34 insertions, 0 deletions

diff --git a/net/wireless/core.c b/net/wireless/core.c
index 0743449405ca..456e4c38c279 100644
--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -321,6 +321,20 @@ static void cfg80211_destroy_iface_wk(struct work_struct *work)
         rtnl_unlock();
 }
 
+static void cfg80211_sched_scan_stop_wk(struct work_struct *work)
+{
+        struct cfg80211_registered_device *rdev;
+
+        rdev = container_of(work, struct cfg80211_registered_device,
+                           sched_scan_stop_wk);
+
+        rtnl_lock();
+
+        __cfg80211_stop_sched_scan(rdev, false);
+
+        rtnl_unlock();
+}
+
 /* exported functions */
 
 struct wiphy *wiphy_new_nm(const struct cfg80211_ops *ops, int sizeof_priv,
@@ -407,6 +421,7 @@ use_default_name:
         INIT_LIST_HEAD(&rdev->destroy_list);
         spin_lock_init(&rdev->destroy_list_lock);
         INIT_WORK(&rdev->destroy_work, cfg80211_destroy_iface_wk);
+        INIT_WORK(&rdev->sched_scan_stop_wk, cfg80211_sched_scan_stop_wk);
 
 #ifdef CONFIG_CFG80211_DEFAULT_PS
         rdev->wiphy.flags |= WIPHY_FLAG_PS_ON_BY_DEFAULT;
@@ -787,6 +802,7 @@ void wiphy_unregister(struct wiphy *wiphy)
         flush_work(&rdev->event_work);
         cancel_delayed_work_sync(&rdev->dfs_update_channels_wk);
         flush_work(&rdev->destroy_work);
+        flush_work(&rdev->sched_scan_stop_wk);
 
 #ifdef CONFIG_PM
         if (rdev->wiphy.wowlan_config && rdev->ops->set_wakeup)
diff --git a/net/wireless/core.h b/net/wireless/core.h
index e82030c32311..801cd49c5a0c 100644
--- a/net/wireless/core.h
+++ b/net/wireless/core.h
@@ -91,6 +91,8 @@ struct cfg80211_registered_device {
         struct list_head destroy_list;
         struct work_struct destroy_work;
 
+        struct work_struct sched_scan_stop_wk;
+
         /* must be last because of the way we do wiphy_priv(),
          * and it should at least be aligned to NETDEV_ALIGN */
         struct wiphy wiphy __aligned(NETDEV_ALIGN);
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index bacdf22fa472..702920134b34 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -6214,6 +6214,9 @@ static int nl80211_start_sched_scan(struct sk_buff *skb,
         sched_scan_req->dev = dev;
         sched_scan_req->wiphy = &rdev->wiphy;
 
+        if (info->attrs[NL80211_ATTR_SOCKET_OWNER])
+                sched_scan_req->owner_nlportid = info->snd_portid;
+
         rcu_assign_pointer(rdev->sched_scan_req, sched_scan_req);
 
         nl80211_send_sched_scan(rdev, dev,
@@ -12618,6 +12621,13 @@ static int nl80211_netlink_notify(struct notifier_block * nb,
 
         list_for_each_entry_rcu(rdev, &cfg80211_rdev_list, list) {
                 bool schedule_destroy_work = false;
+                bool schedule_scan_stop = false;
+                struct cfg80211_sched_scan_request *sched_scan_req =
+                        rcu_dereference(rdev->sched_scan_req);
+
+                if (sched_scan_req && notify->portid &&
+                    sched_scan_req->owner_nlportid == notify->portid)
+                        schedule_scan_stop = true;
 
                 list_for_each_entry_rcu(wdev, &rdev->wdev_list, list) {
                         cfg80211_mlme_unregister_socket(wdev, notify->portid);
@@ -12648,6 +12658,12 @@ static int nl80211_netlink_notify(struct notifier_block * nb,
                                 spin_unlock(&rdev->destroy_list_lock);
                                 schedule_work(&rdev->destroy_work);
                         }
+                } else if (schedule_scan_stop) {
+                        sched_scan_req->owner_nlportid = 0;
+
+                        if (rdev->ops->sched_scan_stop &&
+                            rdev->wiphy.flags & WIPHY_FLAG_SUPPORTS_SCHED_SCAN)
+                                schedule_work(&rdev->sched_scan_stop_wk);
                 }
         }