mac80211: Warn if the rate controller requests retries for a NO_ACK frame

To deter future rate scaling algorithm writers from requesting NO_ACK
packets to be retried, throw a WARN_ON_ONCE if the algorithm hands us
a try count over 1 for NO_ACK packet.

Signed-off-by: Gábor Stefanik <netrolller.3d@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 1564a3018cf5..36e8e2de980c 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -558,6 +558,10 @@ ieee80211_tx_h_rate_ctrl(struct ieee80211_tx_data *tx)
         if (unlikely(!info->control.rates[0].count))
                 info->control.rates[0].count = 1;
 
+        if (WARN_ON_ONCE((info->control.rates[0].count > 1) &&
+                         (info->flags & IEEE80211_TX_CTL_NO_ACK)))
+                info->control.rates[0].count = 1;
+
         if (is_multicast_ether_addr(hdr->addr1)) {
                 /*
                  * XXX: verify the rate is in the basic rateset