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>

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 1564a30..36e8e2d 100644 (file)
--- 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 (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
        if (is_multicast_ether_addr(hdr->addr1)) {
                /*
                 * XXX: verify the rate is in the basic rateset