cfg80211: keep track of BSSes

In order to avoid problems with BSS structs going away
while they're in use, I've long wanted to make cfg80211
keep track of them. Without the SME, that wasn't doable
but now that we have the SME we can do this too. It can
keep track of up to four separate authentications and
one association, regardless of whether it's controlled
by the cfg80211 SME or the userspace SME.

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

1 files changed, 5 insertions, 26 deletions

diff --git a/net/wireless/scan.c b/net/wireless/scan.c
index 82b33e708488..925399462a79 100644
--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -70,6 +70,8 @@ static void bss_release(struct kref *ref)
         if (bss->ies_allocated)
                 kfree(bss->pub.information_elements);
 
+        BUG_ON(atomic_read(&bss->hold));
+
         kfree(bss);
 }
 
@@ -92,8 +94,9 @@ void cfg80211_bss_expire(struct cfg80211_registered_device *dev)
         bool expired = false;
 
         list_for_each_entry_safe(bss, tmp, &dev->bss_list, list) {
-                if (bss->hold ||
-                    !time_after(jiffies, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE))
+                if (atomic_read(&bss->hold))
+                        continue;
+                if (!time_after(jiffies, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE))
                         continue;
                 list_del(&bss->list);
                 rb_erase(&bss->rbn, &dev->bss_tree);
@@ -553,30 +556,6 @@ void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
 }
 EXPORT_SYMBOL(cfg80211_unlink_bss);
 
-void cfg80211_hold_bss(struct cfg80211_bss *pub)
-{
-        struct cfg80211_internal_bss *bss;
-
-        if (!pub)
-                return;
-
-        bss = container_of(pub, struct cfg80211_internal_bss, pub);
-        bss->hold = true;
-}
-EXPORT_SYMBOL(cfg80211_hold_bss);
-
-void cfg80211_unhold_bss(struct cfg80211_bss *pub)
-{
-        struct cfg80211_internal_bss *bss;
-
-        if (!pub)
-                return;
-
-        bss = container_of(pub, struct cfg80211_internal_bss, pub);
-        bss->hold = false;
-}
-EXPORT_SYMBOL(cfg80211_unhold_bss);
-
 #ifdef CONFIG_WIRELESS_EXT
 int cfg80211_wext_siwscan(struct net_device *dev,
                           struct iw_request_info *info,