mac80211: don't send empty extended rates IE
The association request includes a list of supported data rates.
802.11b: 4 supported rates.
802.11g: 12 (8 + 4) supported rates.
802.11a: 8 supported rates.
The rates tag of the assoc request has room for only 8 rates. In case of
802.11g an extended rate tag is appended. However in net/wireless/mlme.c
an extended (empty) rate tag is also appended if the number of rates is
exact 8. This empty (length=0) extended rates tag causes some APs to
deny association with code 18 (unsupported rates). These APs include my
ZyXEL G-570U, and according to Tomas Winkler som Cisco APs.
'If count == 8' has been used to check for the need for an extended rates
tag. But count would also be equal to 8 if the for loop exited because of
no more supported rates. Therefore a check for count being less than
rates_len would seem more correct.
Thanks to:
* Dan Williams for newbie guidance
* Tomas Winkler for confirming the problem
Signed-off-by: Jan-Espen Pettersen <sigsegv@radiotube.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 09a56e2..74777ad 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -783,7 +783,7 @@
}
}
- if (count == 8) {
+ if (rates_len > count) {
pos = skb_put(skb, rates_len - count + 2);
*pos++ = WLAN_EID_EXT_SUPP_RATES;
*pos++ = rates_len - count;