From patchwork Sat May 7 08:37:06 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Wetzel X-Patchwork-Id: 12841901 X-Patchwork-Delegate: johannes@sipsolutions.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D63DCC433EF for ; Sat, 7 May 2022 08:37:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1379079AbiEGIli (ORCPT ); Sat, 7 May 2022 04:41:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57414 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346493AbiEGIlh (ORCPT ); Sat, 7 May 2022 04:41:37 -0400 Received: from ns2.wdyn.eu (ns2.wdyn.eu [5.252.227.236]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 043A8396B6 for ; Sat, 7 May 2022 01:37:50 -0700 (PDT) From: Alexander Wetzel DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=wetzel-home.de; s=wetzel-home; t=1651912666; bh=dT+iblPp+xRuQZDcFiqTIbaNZ+jQOJ9N38bC6ynCXR8=; h=From:To:Cc:Subject:Date; b=BjNZk896zgap26LajhsrIyV3tQE09flenRDK9JAjd9O/Q2fSSvchhllTWsjquXPe6 Lfbm0i//g4Ro5QcUuqU5Y4tItEdX1SNpQxtQsM0v4KntFpL5lPEmN0qAYwh8nV93l8 5pMotN1iPDUiLuYBG8ZEW1JbygWbTNbgUMbnnPaE= To: Johannes Berg Cc: linux-wireless@vger.kernel.org, Alexander Wetzel , Pierre Asselin Subject: [PATCH] mac80211: Use full queue selection code for control port tx Date: Sat, 7 May 2022 10:37:06 +0200 Message-Id: <20220507083706.384513-1-alexander@wetzel-home.de> X-Mailer: git-send-email 2.35.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org Calling only __ieee80211_select_queue() for control port TX exposes drivers which do not support QoS to non-zero values in skb->queue_mapping and even can assign not available queues to info->hw_queue. This can cause issues for drivers like we did e.g. see in '746285cf81dc ("rtl818x: Prevent using not initialized queues")'. This also prevents a redundant call to __ieee80211_select_queue() when using control port TX with iTXQ (pull path). And it starts to prioritize 802.11 preauthentication frames (ETH_P_PREAUTH) on all TX paths. Pierre Asselin confirmed that this patch indeed prevents crashing his system without '746285cf81dc ("rtl818x: Prevent using not initialized queues")'. Tested-by: Pierre Asselin Signed-off-by: Alexander Wetzel --- Starting to prioritize ETH_P_PREAUTH was just added since I noticed that contradictory to at least my expectations control port does accept ETH_P_PREAUTH but handles these like a normal frame for the priority. That can be broken out or even drop, when needed. While looking at the code I also tripped over multiple other questions and I'll probably propose a much more invasive change how to handle the queue assignment. (End2end we seem to do some quite stupid things.) Additionally I really don't get why we call skb_get_hash() on queue assignment: I found the commit '180ac48ee62f ("mac80211: calculate skb hash early when using itxq")' but don't see why calculating the hash early is useful. Any hints here are appreciated. fq_flow_idx() seems to do that when needed and I can't find any other usage of the hash... net/mac80211/tx.c | 18 +++--------------- net/mac80211/wme.c | 3 ++- 2 files changed, 5 insertions(+), 16 deletions(-) diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c index 0e4efc08c762..2fabf6c4547c 100644 --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -5727,7 +5727,6 @@ int ieee80211_tx_control_port(struct wiphy *wiphy, struct net_device *dev, { struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev); struct ieee80211_local *local = sdata->local; - struct sta_info *sta; struct sk_buff *skb; struct ethhdr *ehdr; u32 ctrl_flags = 0; @@ -5771,20 +5770,9 @@ int ieee80211_tx_control_port(struct wiphy *wiphy, struct net_device *dev, skb_reset_network_header(skb); skb_reset_mac_header(skb); - /* update QoS header to prioritize control port frames if possible, - * priorization also happens for control port frames send over - * AF_PACKET - */ - rcu_read_lock(); - - if (ieee80211_lookup_ra_sta(sdata, skb, &sta) == 0 && !IS_ERR(sta)) { - u16 queue = __ieee80211_select_queue(sdata, sta, skb); - - skb_set_queue_mapping(skb, queue); - skb_get_hash(skb); - } - - rcu_read_unlock(); + /* skb bypassed queue selection in net/core/dev.c, do it now */ + skb_set_queue_mapping(skb, ieee80211_select_queue(sdata, skb)); + skb_get_hash(skb); /* mutex lock is only needed for incrementing the cookie counter */ mutex_lock(&local->mtx); diff --git a/net/mac80211/wme.c b/net/mac80211/wme.c index 62c6733e0792..774afefbe0b0 100644 --- a/net/mac80211/wme.c +++ b/net/mac80211/wme.c @@ -160,7 +160,8 @@ u16 __ieee80211_select_queue(struct ieee80211_sub_if_data *sdata, return IEEE80211_AC_BE; } - if (skb->protocol == sdata->control_port_protocol) { + if (skb->protocol == sdata->control_port_protocol || + skb->protocol == cpu_to_be16(ETH_P_PREAUTH)) { skb->priority = 7; goto downgrade; }