I have the problem when using 2.6.29 and judging by the code the situation
stays the same with wireless-testing, even after the fix "mac80211: deauth when
interface is marked down" (the fix doesn't work with kernel 2.6.28 or later, as
I'll explain).
The problem is, with latest kernels wpa_supplicant isn't still notified when
interface goes down, even after commit "mac80211: deauth when interface is
marked down" (e327b847 on Linus tree). There isn't a problem with this commit,
but because of other code changes it doesn't work on latest kernels (but works
if I apply same/similar change on 2.6.27 for example).
The issue is as follows: after commit "mac80211: restructure disassoc/deauth
flows" in 2.6.28, the call to ieee80211_sta_deauthenticate added by commit
e327b847 will not work: because we do sta_info_flush(local, sdata); inside
ieee80211_stop (iface.c), all stations in interface are cleared, so when calling
ieee80211_sta_deauthenticate->ieee80211_set_disassoc (mlme.c), inside
ieee80211_set_disassoc we have this in the beginning:
sta = sta_info_get(local, ifsta->bssid);
if (!sta) {
the !sta check triggers, so the function returns early and
ieee80211_sta_send_apinfo(sdata, ifsta); later isn't called, so wpa_supplicant
isn't notified with SIOCGIWAP
One possible fix is moving sta_info_flush, to avoid !sta, and seems good, like
the following:
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index 2acc416..0929581 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -370,25 +370,6 @@ static int ieee80211_stop(struct net_device *dev)
rcu_read_unlock();
/*
- * Remove all stations associated with this interface.
- *
- * This must be done before calling ops->remove_interface()
- * because otherwise we can later invoke ops->sta_notify()
- * whenever the STAs are removed, and that invalidates driver
- * assumptions about always getting a vif pointer that is valid
- * (because if we remove a STA after ops->remove_interface()
- * the driver will have removed the vif info already!)
- *
- * We could relax this and only unlink the stations from the
- * hash table and list but keep them on a per-sdata list that
- * will be inserted back again when the interface is brought
- * up again, but I don't currently see a use case for that,
- * except with WDS which gets a STA entry created when it is
- * brought up.
- */
- sta_info_flush(local, sdata);
-
- /*
* Don't count this interface for promisc/allmulti while it
* is down. dev_mc_unsync() will invoke set_multicast_list
* on the master interface which will sync these down to the
@@ -539,6 +520,26 @@ static int ieee80211_stop(struct net_device *dev)
conf.mac_addr = dev->dev_addr;
/* disable all keys for as long as this netdev is down */
ieee80211_disable_keys(sdata);
+
+ /*
+ * Remove all stations associated with this interface.
+ *
+ * This must be done before calling ops->remove_interface()
+ * because otherwise we can later invoke ops->sta_notify()
+ * whenever the STAs are removed, and that invalidates driver
+ * assumptions about always getting a vif pointer that is valid
+ * (because if we remove a STA after ops->remove_interface()
+ * the driver will have removed the vif info already!)
+ *
+ * We could relax this and only unlink the stations from the
+ * hash table and list but keep them on a per-sdata list that
+ * will be inserted back again when the interface is brought
+ * up again, but I don't currently see a use case for that,
+ * except with WDS which gets a STA entry created when it is
+ * brought up.
+ */
+ sta_info_flush(local, sdata);
+
local->ops->remove_interface(local_to_hw(local), &conf);
}
My question is, is the patch above safe? that is, do we need to always
call sta_info_flush on interface down like currently, or just for the case we
call remove_interface, like the comment states? if the latter, patch above
is good, and solves the wpa_supplicant/userspace issue.
--
[]'s
Herton.
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