mac80211: Fix n-band association problem

There are two structures named wmm_info and wmm_param, they are used while
parsing the beacon frame. (Check the function ieee802_11_parse_elems).
Certain APs like D-link does not set the fifth bit in WMM IE.
While sending the association request to n-only ap it checks for wmm_ie.
If it is set then only ieee80211_ht_cap is sent during association request.
So n-only association fails.
And this patch fixes this problem by copying the wmm_info to wmm_ie,
which enables the "wmm" flag in iee80211_send_assoc.

Signed-off-by: Abhijeet Kolekar <abhijeet.kolekar@intel.com>
Acked-by: Ron Rindjunsky <ron.rindjunsky@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 6b75cb6c63008370a081dfc68e1a892cdd02d0dd..c0a5345c8a6165175da3a92aa25da3b972425f86 100644 (file)
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -2709,7 +2709,26 @@ static void ieee80211_rx_bss_info(struct net_device *dev,
                        bss->wmm_ie_len = elems.wmm_param_len + 2;
                } else
                        bss->wmm_ie_len = 0;
-       } else if (!elems.wmm_param && bss->wmm_ie) {
+       } else if (elems.wmm_info &&
+                   (!bss->wmm_ie || bss->wmm_ie_len != elems.wmm_info_len ||
+                    memcmp(bss->wmm_ie, elems.wmm_info, elems.wmm_info_len))) {
+                /* As for certain AP's Fifth bit is not set in WMM IE in
+                 * beacon frames.So while parsing the beacon frame the
+                 * wmm_info structure is used instead of wmm_param.
+                 * wmm_info structure was never used to set bss->wmm_ie.
+                 * This code fixes this problem by copying the WME
+                 * information from wmm_info to bss->wmm_ie and enabling
+                 * n-band association.
+                 */
+               kfree(bss->wmm_ie);
+               bss->wmm_ie = kmalloc(elems.wmm_info_len + 2, GFP_ATOMIC);
+               if (bss->wmm_ie) {
+                       memcpy(bss->wmm_ie, elems.wmm_info - 2,
+                              elems.wmm_info_len + 2);
+                       bss->wmm_ie_len = elems.wmm_info_len + 2;
+               } else
+                       bss->wmm_ie_len = 0;
+       } else if (!elems.wmm_param && !elems.wmm_info && bss->wmm_ie) {
                kfree(bss->wmm_ie);
                bss->wmm_ie = NULL;
                bss->wmm_ie_len = 0;