Return-path: Received: from smtp-out04.msg.oleane.net ([62.161.7.2]:57142 "EHLO smtp-out04.msg.oleane.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754135AbcLNSgy (ORCPT ); Wed, 14 Dec 2016 13:36:54 -0500 From: "Jean-Pierre Tosoni" To: "'Ben Greear'" , , References: <004a01d24fe2$94da8dc0$be8fa940$@acksys.fr> <63c731f2-ee21-6450-2ae4-2808e7130eb5@candelatech.com> In-Reply-To: <63c731f2-ee21-6450-2ae4-2808e7130eb5@candelatech.com> Subject: RE: ath10k firmware sends probes on DFS channels without radar detection Date: Wed, 14 Dec 2016 19:14:13 +0100 Message-ID: <00e701d25635$e0108480$a0318d80$@acksys.fr> (sfid-20161214_193658_272638_54C4E795) MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Sender: linux-wireless-owner@vger.kernel.org List-ID: On 12/06/15 08:36 PM, Ben Greear wrote: > On 12/06/2016 09:02 AM, Jean-Pierre Tosoni wrote: > > This follows on the previous discussion > > "Client station sends probes on DFS channels" > > > > Problem: > > The combination of QCA988X firmware v10.2.4.70-2 + ath10k + > > wpa_supplicant do not comply with the norm ETSI/EN 301-893 section > > 4.7; because they can send probes for 600s when no AP is around. > > > > Analysis: > > The problem seems to lie in the firmware, which regards the presence > > of *any* beacon as a proof that the channel is radar-clean for 600s. > > > > This is a wrong hypothesis, since a rogue AP sending fraudulent > > beacons should not induce a scrupulous STA in sending illegal probes. > > > > Moreover, the norm (table D.1) sets a time limit of 10s to shutdown > > when no AP positively allows the STA to transmit on the DFS channel. > > > > Status: > > - there is no known plan at QCA to fix the issue. > > - ath10k firmware is not publicly available for fixes. > > - there is no obvious fix working in ath10k. > > - the issue does not show up with other mac80211 devices like ath9k. > > - wpa_supplicant considers this is a kernel issue [2] > > Have you confirmed that there are no probe requests being sent by ath10k > driver? I have put a printk in the ath10k_tx function (in the path for management frames) and it does not show up. On another hand I cannot find any other function preparing / sending probes. There is only the wmi command that starts scans. > > You could also try disabling the station keep-alive and roaming logic in > the firmware by tweaking the wmi initial setup logic. I disable that in > my firmware, for instance, because mac80211 can do a better job and then I > can save resources in the firmware. Do you mean the values set in wmi.c:: ath10k_wmi_start_scan_init() ? Should I replace all the scan offload by a mac80211-controlled scan like in ath9k? The problem then is to switch channels; channel switching seems very different from ath9k. Thanks, JP > Finally, if that doesn't work, then I could probably fix that in CT > firmware in case that is of interest. > > Thanks, > Ben > > > > > Jean-Pierre Tosoni > > > > > > > >> -----Message d'origine----- > >> De : ath10k [mailto:ath10k-bounces@lists.infradead.org] De la part de > >> Jean-Pierre Tosoni Envoy? : mercredi 30 novembre 2016 19:04 ? : > >> ath10k@lists.infradead.org Objet : Client station sends probes on DFS > >> channels > >> > >> Hello list, > >> > >> There is a case where I can see probes on a DFS channel, from a non- > >> associated station using ath10k. (note that the problem does not > >> arise when using ath9k). > >> > >> *The setup* > >> > >> I am using Openwrt, wpa_supplicant and compat-wireless 2016-10-08, > >> Card firmware is ath10k_pci: qca988x hw2.0 (0x4100016c, 0x043202ff) > >> fw 10.2.4.70-2 api 5 htt-ver 2.1 wmi-op 5 htt-op 2 > >> cal otp max-sta 128 features no-p2p > >> ath10k_pci: debug 0 debugfs 1 tracing 0 dfs 1 testmode 1 > >> > >> I am using channel 116, regdom US or FR, where I see no traffic at > >> all using wireshark+Airpcap. > >> I set wpa_supplicant to scan this channel only for a specific SSID > >> "ssid1". > >> > >> At initial startup of the client device, no probes are going out, > >> which is OK. > >> > >> Then, on another device, I start a hostapd set to channel 116, with a > >> different SSID "otherssid" so that the supplicant will not associate. > >> > >> Shortly (1-2s) after the beacons appear in the air, the client begins > >> to Send probe request in the air, which is unexpected, but acceptable > >> since the client can infer absence of radars from the presence of > beacons. > >> > >> *The problem* > >> > >> If I power down the AP, the client continues to send probes for > >> around > >> 10 minutes, which is unacceptable since it cannot handle radar > >> detection, as it is a slave device in the meaning of ETSI/EN 301- > 893[1]. > >> > >> > >> Some tests I made: > >> - I tried to investigate the "beacon hint" mechanism but it appears > >> that it is not used on DFS channels. > >> > >> - I tried to force the IEEE80211_NO_IR flag when IEEE80211_CHAN_DFS > >> is set. > >> > >> - When I reload the reg. domain using "iw reg set", the probes cease, > >> but will reappear if I cycle my AP again On then Off. > >> > >> - When I let the client associate, then disassociate and stop the AP, > >> the same problem arises. It disappears if I add a call to > >> ath10k_regd_update() in mac.c after a disconnection (This is not a > >> fix, since in my case the client never associates). > >> > >> - Since at startup, the client does not send probes, I infer that the > >> problem is *not* caused by a hidden AP that the card could see but > >> not airpcap. > >> > >> - I tried with channels 52 and 100, with regdom FR or US: same problem. > >> > >> Any ideas? > >> > >> > >> [1] http://www.etsi.org/deliver/etsi_en/301800_301899/301893/ > >> 01.08.01_60/en_301893v010801p.pdf > > [2] http://lists.shmoo.com/pipermail/hostap/2015-January/031906.html > >> > >> J.P. Tosoni - ACKSYS > >> > >> > >> > >> > >> _______________________________________________ > >> ath10k mailing list > >> ath10k@lists.infradead.org > >> http://lists.infradead.org/mailman/listinfo/ath10k > > > > > -- > Ben Greear > Candela Technologies Inc http://www.candelatech.com > > > _______________________________________________ > ath10k mailing list > ath10k@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/ath10k