mac80211: reject aggregation sessions with non-HT peers

If a peer or some local agent (rate control, ...) decides to start
an aggregation session but doesn't support HT (which also implies
QoS), reject it.

This is mostly a corner case as such peers normally won't try to
use block-ack sessions and rate control wouldn't start them, but
technically QoS stations could request it according to the spec.

However, since drivers don't really support such non-HT sessions
it's better to reject them.

Also, while at it, move the tracing for TX sessions earlier so it
captures the error cases as well.

Reviewed-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/net/mac80211/agg-rx.c b/net/mac80211/agg-rx.c
index a48bad468880..2c090c507391 100644
--- a/net/mac80211/agg-rx.c
+++ b/net/mac80211/agg-rx.c
@@ -234,6 +234,14 @@ void __ieee80211_start_rx_ba_session(struct sta_info *sta,
         int i, ret = -EOPNOTSUPP;
         u16 status = WLAN_STATUS_REQUEST_DECLINED;
 
+        if (!sta->sta.ht_cap.ht_supported) {
+                ht_dbg(sta->sdata,
+                       "STA %pM erroneously requests BA session on tid %d w/o QoS\n",
+                       sta->sta.addr, tid);
+                /* send a response anyway, it's an error case if we get here */
+                goto end_no_lock;
+        }
+
         if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) {
                 ht_dbg(sta->sdata,
                        "Suspend in progress - Denying ADDBA request (%pM tid %d)\n",