cfg80211: allow users to request removing a BSS

This patch introduces cfg80211_unlink_bss, a function to
allow a driver to remove a BSS from the internal list and
make it not show up in scan results any more -- this is
to be used when the driver detects that the BSS is no
longer available.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

2 files changed, 32 insertions, 0 deletions

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index b514abcc2b93..f1d21570e6cb 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -791,5 +791,16 @@ struct cfg80211_bss *cfg80211_get_mesh(struct wiphy *wiphy,
                                        const u8 *meshid, size_t meshidlen,
                                        const u8 *meshcfg);
 void cfg80211_put_bss(struct cfg80211_bss *bss);
+/**
+ * cfg80211_unlink_bss - unlink BSS from internal data structures
+ * @wiphy: the wiphy
+ * @bss: the bss to remove
+ *
+ * This function removes the given BSS from the internal data structures
+ * thereby making it no longer show up in scan results etc. Use this
+ * function when you detect a BSS is gone. Normally BSSes will also time
+ * out, so it is not necessary to use this function at all.
+ */
+void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *bss);
 
 #endif /* __NET_CFG80211_H */
diff --git a/net/wireless/scan.c b/net/wireless/scan.c
index ec148f68a62b..aacccc9ab6ca 100644
--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -432,6 +432,27 @@ void cfg80211_put_bss(struct cfg80211_bss *pub)
 }
 EXPORT_SYMBOL(cfg80211_put_bss);
 
+void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
+{
+        struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
+        struct cfg80211_internal_bss *bss;
+
+        if (WARN_ON(!pub))
+                return;
+
+        bss = container_of(pub, struct cfg80211_internal_bss, pub);
+
+        spin_lock_bh(&dev->bss_lock);
+
+        list_del(&bss->list);
+        rb_erase(&bss->rbn, &dev->bss_tree);
+
+        spin_unlock_bh(&dev->bss_lock);
+
+        kref_put(&bss->ref, bss_release);
+}
+EXPORT_SYMBOL(cfg80211_unlink_bss);
+
 #ifdef CONFIG_WIRELESS_EXT
 int cfg80211_wext_siwscan(struct net_device *dev,
                           struct iw_request_info *info,