Return-path: Received: from s3.sipsolutions.net ([5.9.151.49]:50872 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751154AbbI3PRI (ORCPT ); Wed, 30 Sep 2015 11:17:08 -0400 Message-ID: <1443626224.1859.9.camel@sipsolutions.net> (sfid-20150930_171712_220189_861D907C) Subject: Re: Can we ignore frames with invalid BSSID in IBSS mode? From: Johannes Berg To: Ben Greear , "linux-wireless@vger.kernel.org" , ath10k Date: Wed, 30 Sep 2015 17:17:04 +0200 In-Reply-To: <560BFABC.8090504@candelatech.com> References: <5605D228.7050609@candelatech.com> (sfid-20150926_010105_789618_F93D668E) <1443595615.1859.2.camel@sipsolutions.net> <560BFABC.8090504@candelatech.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Wed, 2015-09-30 at 08:07 -0700, Ben Greear wrote: > > On 09/29/2015 11:46 PM, Johannes Berg wrote: > > On Fri, 2015-09-25 at 16:00 -0700, Ben Greear wrote: > > > It seems that ath10k ar988X hardware has a bug where the BSSID > > > for IBSS AMSDU frames is all zeros. The 'main' 636 ath10k firmware > > > does not seem to use AMSDUs for IBSS, and when I enable it in my CT > > > firmware, then I see the breakage. So, I suspect it is not > > > just a simple software/firmware bug. > > > > > > If I simply ignore the bssid_match check in ieee80211_accept_frame, > > > then it seems everything runs fine. > > > > > > So, I'm curious if anyone knows what sorts of bad things could happen > > > if the bssid_match check is ignored? Maybe bcast/mcast frames could > > > be accepted when they shouldn't be in certain cases? > > > > > > > You could end up accepting multicast frames from a different, > > overlapping, BSS? Seems like a bad idea. > > It's definitely not a great idea. > > In my testing, I always see the first frame of the AMPDU have > a proper IBSS BSSID. Any idea if it would be OK (and even possible) > for the driver or stack to detect this and save the BSSID aside > for the subsequent frames? That seems reasonable. > Its not clear to me whether the rest of the AMPDU frames could > somehow be interleaved with frames from a different BSSID? > They can't be, at least not without some very strange hacks on the transmitter. johannes