mac80211: fix deauth before assoc

From: Johannes Berg <[email protected]>

When we receive a deauthentication frame before having successfully associated, we neither print a message nor abort assocation. The former makes it hard to debug, while the latter later causes a warning in cfg80211 when, as will typically be the case, association timed out.

This warning was reported by many, e.g. in
https://bugzilla.kernel.org/show_bug.cgi?id=15981,
but I couldn't initially pinpoint it. I verified the fix by hacking hostapd to send a deauth frame instead of an association response.

Cc [email protected]

Signed-off-by Johannes Berg <[email protected]>

---
 net/mac80211/mlme.c |   39 ++++++++++++++++++++++++++++++++++++++-

 1 file changed, 38 insertions(+), 1 deletion(-)

net/mac80211/mlme.c        2010-06-07 21:46:00.000000000 +0200 renamed from net/mac80211/mlme.c   2010-06-07 21:35:41.000000000 +0200 +0 -0

@@ -1695,8 +1695,45 @@ void ieee80211_sta_rx_queued_mgmt(struct
        mutex_unlock(&ifmgd->mtx);
 

       if (skb->len >= 24 + 2 /* mgmt + deauth reason */ &&
-           (fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_DEAUTH)
+           (fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_DEAUTH) {
+               struct ieee80211_local *local = sdata->local;
+               struct ieee80211_work *wk;

net/mac80211/mlme.c        2010-06-07 21:46:00.000000000 +0200 renamed from net/mac80211/mlme.c   2010-06-07 21:35:41.000000000 +0200 +34 -0

+
+               mutex_lock(&local->work_mtx);
+               list_for_each_entry(wk, &local->work_list, list) {
+                       if (wk->sdata != sdata)
+                               continue;
+
+                       if (wk->type != IEEE80211_WORK_ASSOC)
+                               continue;
+
+                       if (memcmp(mgmt->bssid, wk->filter_ta, ETH_ALEN))
+                               continue;
+                       if (memcmp(mgmt->sa, wk->filter_ta, ETH_ALEN))
+                               continue;
+
+                       /*
+                        * Printing the message only here means we can't
+                        * spuriously print it, but it also means that it
+                        * won't be printed when the frame comes in before
+                        * we even tried to associate or in similar cases.
+                        *
+                        * Ultimately, I suspect cfg80211 should print the
+                        * messages instead.
+                        */
+                       printk(KERN_DEBUG
+                              "%s: deauthenticated from %pM (Reason: %u)\n",
+                              sdata->name, mgmt->bssid,
+                              le16_to_cpu(mgmt->u.deauth.reason_code));
+
+                       list_del_rcu(&wk->list);
+                       free_work(wk);
+                       break;
+               }
+               mutex_unlock(&local->work_mtx);
+

               cfg80211_send_deauth(sdata->dev, (u8 *)mgmt, skb->len);
+       }
 }

 static void ieee80211_sta_timer(unsigned long data)

From: Johannes Berg <[email protected]>

When we receive a deauthentication frame before
having successfully associated, we neither print
a message nor abort assocation. The former makes
it hard to debug, while the latter later causes
a warning in cfg80211 when, as will typically be
the case, association timed out.

This warning was reported by many, e.g. in
https://bugzilla.kernel.org/show_bug.cgi?id=15981,
but I couldn't initially pinpoint it. I verified
the fix by hacking hostapd to send a deauth frame
instead of an association response.

Cc [email protected]

Signed-off-by Johannes Berg <[email protected]>

---
That previous one didn't even apply to the right tree, how did you ever test it? Or did you just fix up the context?

Quoted 2 lines

That previous one didn't even apply to the right tree, how did you ever test it? Or did you just fix up the context?

patching file net/mac80211/mlme.c
Hunk #1 succeeded at 1722 with fuzz 3 (offset 27 lines).