mac80211: Account HT Control field in Data frame hdrlen according to 802.11n-2009

ieee80211_hdrlen() should account account new HT Control field in 802.11
data frame header introduced by IEEE 802.11n standard.

According to 802.11n-2009 HT Control field is present in data frames
when both of following are met:

   1. It is QoS data frame.
   2. Order bit is set in Frame Control field.

The change might be totally compatible with legacy non-11n aware frames,
because 802.11-2007 standard states that "all QoS STAs set this subfield
to 0".

Signed-off-by: Andriy V. Tkachuk <andrit@ukr.net>
Acked-by : Benoit Papillault <benoit.papillault@free.fr>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 4 insertions, 1 deletions

diff --git a/net/wireless/util.c b/net/wireless/util.c
index 23557c1d0a9c..be2ab8c59e3a 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -227,8 +227,11 @@ unsigned int ieee80211_hdrlen(__le16 fc)
         if (ieee80211_is_data(fc)) {
                 if (ieee80211_has_a4(fc))
                         hdrlen = 30;
-                if (ieee80211_is_data_qos(fc))
+                if (ieee80211_is_data_qos(fc)) {
                         hdrlen += IEEE80211_QOS_CTL_LEN;
+                        if (ieee80211_has_order(fc))
+                                hdrlen += IEEE80211_HT_CTL_LEN;
+                }
                 goto out;
         }