diff mbox

mac80211: fix DTIM setting

Message ID 1253207963.9450.20.camel@johannes.local (mailing list archive)
State Not Applicable, archived
Headers show

Commit Message

Johannes Berg Sept. 17, 2009, 5:19 p.m. UTC
When the DTIM setting is read from beacons, mac80211 will
assume it is 1 if the TIM IE is not present or the value
is 0. This sounds fine, but the same function processes
probe responses as well, which don't have a TIM IE. This
leads to overwriting any values previously parsed out of
beacon frames.

Thus, instead of checking for the presence of the TIM IE
when setting the default, simply check whether the DTIM
period value is valid already. If the TIM IE is not there
then the value cannot be valid (it is initialised to 0)
and probe responses received after beacons will not lead
to overwriting an already valid value.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
---
It's a bug, but probably not severe enough to warrant looking into
putting it into -stable.

 net/mac80211/scan.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)



--
To unsubscribe from this list: send the line "unsubscribe linux-wireless" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
diff mbox

Patch

--- wireless-testing.orig/net/mac80211/scan.c	2009-09-17 10:14:59.000000000 -0700
+++ wireless-testing/net/mac80211/scan.c	2009-09-17 10:15:18.000000000 -0700
@@ -90,8 +90,8 @@  ieee80211_bss_info_update(struct ieee802
 		bss->dtim_period = tim_ie->dtim_period;
 	}
 
-	/* set default value for buggy APs */
-	if (!elems->tim || bss->dtim_period == 0)
+	/* set default value for buggy AP/no TIM element */
+	if (bss->dtim_period == 0)
 		bss->dtim_period = 1;
 
 	bss->supp_rates_len = 0;