cfg80211: export interface stopping function

This exports a new cfg80211_stop_iface() function.

This is intended for driver internal interface
combination management and channel switching.

Due to locking issues (it re-enters driver) the
call is asynchronous and uses cfg80211 event
list/worker.

Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

7 files changed, 80 insertions, 11 deletions

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 7eae46ccec01..0631230b01eb 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -4756,6 +4756,21 @@ int cfg80211_iter_combinations(struct wiphy *wiphy,
                                             void *data),
                                void *data);
 
+/*
+ * cfg80211_stop_iface - trigger interface disconnection
+ *
+ * @wiphy: the wiphy
+ * @wdev: wireless device
+ * @gfp: context flags
+ *
+ * Trigger interface to be stopped as if AP was stopped, IBSS/mesh left, STA
+ * disconnected.
+ *
+ * Note: This doesn't need any locks and is asynchronous.
+ */
+void cfg80211_stop_iface(struct wiphy *wiphy, struct wireless_dev *wdev,
+                         gfp_t gfp);
+
 /* Logging, debugging and troubleshooting/diagnostic helpers. */
 
 /* wiphy_printk helpers, similar to dev_printk */
diff --git a/net/wireless/ap.c b/net/wireless/ap.c
index 3e02ade508d8..bdad1f951561 100644
--- a/net/wireless/ap.c
+++ b/net/wireless/ap.c
@@ -6,8 +6,8 @@
 #include "rdev-ops.h"
 
 
-static int __cfg80211_stop_ap(struct cfg80211_registered_device *rdev,
-                              struct net_device *dev, bool notify)
+int __cfg80211_stop_ap(struct cfg80211_registered_device *rdev,
+                       struct net_device *dev, bool notify)
 {
         struct wireless_dev *wdev = dev->ieee80211_ptr;
         int err;
diff --git a/net/wireless/core.c b/net/wireless/core.c
index f509da4d9be9..7e023b74f009 100644
--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -792,23 +792,23 @@ void cfg80211_update_iface_num(struct cfg80211_registered_device *rdev,
                 rdev->num_running_monitor_ifaces += num;
 }
 
-void cfg80211_leave(struct cfg80211_registered_device *rdev,
-                    struct wireless_dev *wdev)
+void __cfg80211_leave(struct cfg80211_registered_device *rdev,
+                      struct wireless_dev *wdev)
 {
         struct net_device *dev = wdev->netdev;
 
         ASSERT_RTNL();
+        ASSERT_WDEV_LOCK(wdev);
 
         switch (wdev->iftype) {
         case NL80211_IFTYPE_ADHOC:
-                cfg80211_leave_ibss(rdev, dev, true);
+                __cfg80211_leave_ibss(rdev, dev, true);
                 break;
         case NL80211_IFTYPE_P2P_CLIENT:
         case NL80211_IFTYPE_STATION:
                 if (rdev->sched_scan_req && dev == rdev->sched_scan_req->dev)
                         __cfg80211_stop_sched_scan(rdev, false);
 
-                wdev_lock(wdev);
 #ifdef CONFIG_CFG80211_WEXT
                 kfree(wdev->wext.ie);
                 wdev->wext.ie = NULL;
@@ -817,20 +817,49 @@ void cfg80211_leave(struct cfg80211_registered_device *rdev,
 #endif
                 cfg80211_disconnect(rdev, dev,
                                     WLAN_REASON_DEAUTH_LEAVING, true);
-                wdev_unlock(wdev);
                 break;
         case NL80211_IFTYPE_MESH_POINT:
-                cfg80211_leave_mesh(rdev, dev);
+                __cfg80211_leave_mesh(rdev, dev);
                 break;
         case NL80211_IFTYPE_AP:
         case NL80211_IFTYPE_P2P_GO:
-                cfg80211_stop_ap(rdev, dev, true);
+                __cfg80211_stop_ap(rdev, dev, true);
                 break;
         default:
                 break;
         }
 }
 
+void cfg80211_leave(struct cfg80211_registered_device *rdev,
+                    struct wireless_dev *wdev)
+{
+        wdev_lock(wdev);
+        __cfg80211_leave(rdev, wdev);
+        wdev_unlock(wdev);
+}
+
+void cfg80211_stop_iface(struct wiphy *wiphy, struct wireless_dev *wdev,
+                         gfp_t gfp)
+{
+        struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
+        struct cfg80211_event *ev;
+        unsigned long flags;
+
+        trace_cfg80211_stop_iface(wiphy, wdev);
+
+        ev = kzalloc(sizeof(*ev), gfp);
+        if (!ev)
+                return;
+
+        ev->type = EVENT_STOPPED;
+
+        spin_lock_irqsave(&wdev->event_lock, flags);
+        list_add_tail(&ev->list, &wdev->event_list);
+        spin_unlock_irqrestore(&wdev->event_lock, flags);
+        queue_work(cfg80211_wq, &rdev->event_work);
+}
+EXPORT_SYMBOL(cfg80211_stop_iface);
+
 static int cfg80211_netdev_notifier_call(struct notifier_block *nb,
                                          unsigned long state, void *ptr)
 {
diff --git a/net/wireless/core.h b/net/wireless/core.h
index 681b8fa4355b..e9afbf10e756 100644
--- a/net/wireless/core.h
+++ b/net/wireless/core.h
@@ -185,6 +185,7 @@ enum cfg80211_event_type {
         EVENT_ROAMED,
         EVENT_DISCONNECTED,
         EVENT_IBSS_JOINED,
+        EVENT_STOPPED,
 };
 
 struct cfg80211_event {
@@ -281,6 +282,8 @@ int cfg80211_join_mesh(struct cfg80211_registered_device *rdev,
                        struct net_device *dev,
                        struct mesh_setup *setup,
                        const struct mesh_config *conf);
+int __cfg80211_leave_mesh(struct cfg80211_registered_device *rdev,
+                          struct net_device *dev);
 int cfg80211_leave_mesh(struct cfg80211_registered_device *rdev,
                         struct net_device *dev);
 int cfg80211_set_mesh_channel(struct cfg80211_registered_device *rdev,
@@ -288,6 +291,8 @@ int cfg80211_set_mesh_channel(struct cfg80211_registered_device *rdev,
                               struct cfg80211_chan_def *chandef);
 
 /* AP */
+int __cfg80211_stop_ap(struct cfg80211_registered_device *rdev,
+                       struct net_device *dev, bool notify);
 int cfg80211_stop_ap(struct cfg80211_registered_device *rdev,
                      struct net_device *dev, bool notify);
 
@@ -441,6 +446,8 @@ int cfg80211_validate_beacon_int(struct cfg80211_registered_device *rdev,
 void cfg80211_update_iface_num(struct cfg80211_registered_device *rdev,
                                enum nl80211_iftype iftype, int num);
 
+void __cfg80211_leave(struct cfg80211_registered_device *rdev,
+                      struct wireless_dev *wdev);
 void cfg80211_leave(struct cfg80211_registered_device *rdev,
                     struct wireless_dev *wdev);
 
diff --git a/net/wireless/mesh.c b/net/wireless/mesh.c
index 3ddfb7cd335e..092300b30c37 100644
--- a/net/wireless/mesh.c
+++ b/net/wireless/mesh.c
@@ -238,8 +238,8 @@ int cfg80211_set_mesh_channel(struct cfg80211_registered_device *rdev,
         return 0;
 }
 
-static int __cfg80211_leave_mesh(struct cfg80211_registered_device *rdev,
-                                 struct net_device *dev)
+int __cfg80211_leave_mesh(struct cfg80211_registered_device *rdev,
+                          struct net_device *dev)
 {
         struct wireless_dev *wdev = dev->ieee80211_ptr;
         int err;
diff --git a/net/wireless/trace.h b/net/wireless/trace.h
index f3c13ff4d04c..cdfbb00e1b37 100644
--- a/net/wireless/trace.h
+++ b/net/wireless/trace.h
@@ -2636,6 +2636,21 @@ TRACE_EVENT(cfg80211_ft_event,
                   WIPHY_PR_ARG, NETDEV_PR_ARG, MAC_PR_ARG(target_ap))
 );
 
+TRACE_EVENT(cfg80211_stop_iface,
+        TP_PROTO(struct wiphy *wiphy, struct wireless_dev *wdev),
+        TP_ARGS(wiphy, wdev),
+        TP_STRUCT__entry(
+                WIPHY_ENTRY
+                WDEV_ENTRY
+        ),
+        TP_fast_assign(
+                WIPHY_ASSIGN;
+                WDEV_ASSIGN;
+        ),
+        TP_printk(WIPHY_PR_FMT ", " WDEV_PR_FMT,
+                  WIPHY_PR_ARG, WDEV_PR_ARG)
+);
+
 #endif /* !__RDEV_OPS_TRACE || TRACE_HEADER_MULTI_READ */
 
 #undef TRACE_INCLUDE_PATH
diff --git a/net/wireless/util.c b/net/wireless/util.c
index 7c47fa07b276..a756429b3a0a 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -839,6 +839,9 @@ void cfg80211_process_wdev_events(struct wireless_dev *wdev)
                         __cfg80211_ibss_joined(wdev->netdev, ev->ij.bssid,
                                                ev->ij.channel);
                         break;
+                case EVENT_STOPPED:
+                        __cfg80211_leave(wiphy_to_rdev(wdev->wiphy), wdev);
+                        break;
                 }
                 wdev_unlock(wdev);