cfg80211/nl80211: add support for scheduled scans

Implement new functionality for scheduled scan offload.  With this feature we
can scan automatically at certain intervals.

The idea is that the hardware can perform scan automatically and filter on
desired results without waking up the host unnecessarily.

Add NL80211_CMD_START_SCHED_SCAN and NL80211_CMD_STOP_SCHED_SCAN
commands to the nl80211 interface.  When results are available they are
reported by NL80211_CMD_SCHED_SCAN_RESULTS events.  The userspace is
informed when the scheduled scan has stopped with a
NL80211_CMD_SCHED_SCAN_STOPPED event, which can be triggered either by
the driver or by a call to NL80211_CMD_STOP_SCHED_SCAN.

Signed-off-by: Luciano Coelho <coelho@ti.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 70 insertions, 0 deletions

diff --git a/net/wireless/scan.c b/net/wireless/scan.c
index 62e542a2b192..65dfae3b9d41 100644
--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -93,6 +93,76 @@ void cfg80211_scan_done(struct cfg80211_scan_request *request, bool aborted)
 }
 EXPORT_SYMBOL(cfg80211_scan_done);
 
+void __cfg80211_sched_scan_results(struct work_struct *wk)
+{
+        struct cfg80211_registered_device *rdev;
+
+        rdev = container_of(wk, struct cfg80211_registered_device,
+                            sched_scan_results_wk);
+
+        cfg80211_lock_rdev(rdev);
+
+        /* we don't have sched_scan_req anymore if the scan is stopping */
+        if (rdev->sched_scan_req)
+                nl80211_send_sched_scan_results(rdev,
+                                                rdev->sched_scan_req->dev);
+
+        cfg80211_unlock_rdev(rdev);
+}
+
+void cfg80211_sched_scan_results(struct wiphy *wiphy)
+{
+        /* ignore if we're not scanning */
+        if (wiphy_to_dev(wiphy)->sched_scan_req)
+                queue_work(cfg80211_wq,
+                           &wiphy_to_dev(wiphy)->sched_scan_results_wk);
+}
+EXPORT_SYMBOL(cfg80211_sched_scan_results);
+
+void __cfg80211_sched_scan_stopped(struct work_struct *wk)
+{
+        struct cfg80211_registered_device *rdev;
+
+        rdev = container_of(wk, struct cfg80211_registered_device,
+                            sched_scan_stopped_wk);
+
+        cfg80211_lock_rdev(rdev);
+        __cfg80211_stop_sched_scan(rdev, true);
+        cfg80211_unlock_rdev(rdev);
+}
+
+void cfg80211_sched_scan_stopped(struct wiphy *wiphy)
+{
+        queue_work(cfg80211_wq, &wiphy_to_dev(wiphy)->sched_scan_stopped_wk);
+}
+EXPORT_SYMBOL(cfg80211_sched_scan_stopped);
+
+int __cfg80211_stop_sched_scan(struct cfg80211_registered_device *rdev,
+                               bool driver_initiated)
+{
+        int err;
+        struct net_device *dev;
+
+        ASSERT_RDEV_LOCK(rdev);
+
+        if (!rdev->sched_scan_req)
+                return 0;
+
+        dev = rdev->sched_scan_req->dev;
+
+        err = rdev->ops->sched_scan_stop(&rdev->wiphy, dev,
+                                         driver_initiated);
+        if (err)
+                return err;
+
+        nl80211_send_sched_scan(rdev, dev, NL80211_CMD_SCHED_SCAN_STOPPED);
+
+        kfree(rdev->sched_scan_req);
+        rdev->sched_scan_req = NULL;
+
+        return err;
+}
+
 static void bss_release(struct kref *ref)
 {
         struct cfg80211_internal_bss *bss;