From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id ABBDBC433DF for ; Thu, 25 Jun 2020 09:51:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 865B22076E for ; Thu, 25 Jun 2020 09:51:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390262AbgFYJvy (ORCPT ); Thu, 25 Jun 2020 05:51:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60366 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389744AbgFYJvx (ORCPT ); Thu, 25 Jun 2020 05:51:53 -0400 Received: from sipsolutions.net (s3.sipsolutions.net [IPv6:2a01:4f8:191:4433::2]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 77AECC061573 for ; Thu, 25 Jun 2020 02:51:53 -0700 (PDT) Received: by sipsolutions.net with esmtpsa (TLS1.3:ECDHE_SECP256R1__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.93) (envelope-from ) id 1joOXr-00BnlL-VR; Thu, 25 Jun 2020 11:51:48 +0200 Message-ID: <2a607392179a76f0f6fc3cef2e6e141f25dc0254.camel@sipsolutions.net> Subject: Re: [PATCH] mac80211: Send deauth to STA's upon AP stop From: Johannes Berg To: Shay Bar , Ben Greear Cc: "linux-wireless@vger.kernel.org" Date: Thu, 25 Jun 2020 11:51:47 +0200 In-Reply-To: References: <20200618093609.16514-1-shay.bar@celeno.com> <2a7b33ace030fdeda96e60b2abd6c70a11f426e0.camel@sipsolutions.net> <54236bdd708c53ec2f2a776bb3badcd77c7fecc6.camel@sipsolutions.net> <6da8757ac90a4d34ed1bdc7c84b40aac06c01af9.camel@sipsolutions.net> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.36.3 (3.36.3-1.fc32) MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org On Sun, 2020-06-21 at 10:12 +0000, Shay Bar wrote: > Hi Johannes and Ben, > > To conclude this thread, hostapd doesn’t send any deauth/disassoc > upon AP stop (when hostapd is killed _or_ when "ifconfig down" the > AP interface). Right. I'm sort of suggesting you just shouldn't be doing this, and it doesn't seem like most people actually do, otherwise we'd have seen this issue before? > This is causing a situation where stations keep sending unicast frames > to a down AP interface as it doesn’t know it's gone down. > I tried your suggestion and sent 1 deauth/disassoc as broadcast > (instead of unicast to each STA), but some stations (e.g. Samsung S8) > Ignore this broadcast (while it will not ignore unicast deauth/disassoc). > Although not indicated in the standard, I think it's better to let STA > Know AP gone down by sending this unicast deauth to each STA > (as this patch does). I'm not really sure. That's a _lot_ of frames and potentially quite a long time. In the patch, as written, I'm not even convinced you can be sure that they will all make it out to the air? johannes