From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.netfilter.org (mail.netfilter.org [217.70.190.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D8DF33A961A; Tue, 15 Sep 2026 08:15:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.70.190.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789460134; cv=none; b=h5NsRtGAtIVAAQd0Udbi3XwozPu4MNfTuR2S2IbVziiaht/kn1lYSmiEwhzycICmEjJca+oK1tcg0RoaIxDz+0f3o+qVHH402TOqeIpNXsDV74cZBhUacrZSzTmKiV8uDqYMIfyY4k9F25wfD4VGOOyU3sJ+M27bqmJRdV4u4Xw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789460134; c=relaxed/simple; bh=cPRbZPEs8ojOrPWPVXYqdY5vmFNELiY+U1btNbqjbqo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=OL9/LKzmbqXxjil7oOM/m0qZlrh78YjV2NSkobuaHSRe+cfUrD/DNEfIHvKjfz6fKv+ibQxxeELlXhIZmULa4unfryB3kfAr7+zjmQmp4FOmOE+UczvX6uzFp1ma1D9W2oN1Awo3WhkMkrkJC3uFX1IGe6AODIpybSBUb0Bs3rw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=netfilter.org; spf=pass smtp.mailfrom=netfilter.org; dkim=pass (2048-bit key) header.d=netfilter.org header.i=@netfilter.org header.b=OA4GbUeH; arc=none smtp.client-ip=217.70.190.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=netfilter.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=netfilter.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=netfilter.org header.i=@netfilter.org header.b="OA4GbUeH" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=netfilter.org; s=2025; t=1789460123; bh=+mLf7YJol3PGpt7VzxE3z1ex1n/DMEGBgz1mEFBBuqQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=OA4GbUeHsWCMBylKJv5e4/ybLArn0rDP3Hiyj7oUY1xdS56Y+NRjZ9OOd/ggGguNY AIJEcP3UFMFkymnwKuPaTW5gDAZVLKBwThHwei8lDdkvOpUBOvobvGYmbJKTEJu+/4 7esN1I9zbRhsMVLGJuHCKOmau1+7hJfeMu6Cfl71TOKswGQgNyvof6Y4XuRc4dvZM/ HoO0wSUPF3wkmqrNcdMceCaTXNR8qNfRz5PfYAQWuo6y+heHlOG0Ynzm5Qeqc3eQkJ yoH+AfsanB7Ds0Vja2uvi+w+FwIfuR3ASboQ0HMjIiFCz4OSLhvlA/KNStW2ngXGyv 6PiaeSMmVURpg== Received: from netfilter.org (mail-agni [217.70.190.124]) by mail.netfilter.org (Postfix) with UTF8SMTPSA id D28EF60054; Tue, 15 Sep 2026 10:15:22 +0200 (CEST) Date: Tue, 15 Sep 2026 10:15:20 +0200 From: Pablo Neira Ayuso To: Hauke Mehrtens Cc: stable@vger.kernel.org, "netdev@vger.kernel.org" , netfilter-devel@vger.kernel.org Subject: Re: network flow offloading broken in 6.18.45+ Message-ID: References: <7dfa42f6-64c1-4084-bfea-d57500c245cf@hauke-m.de> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: On Tue, Sep 15, 2026 at 02:20:25AM +0200, Hauke Mehrtens wrote: > On 9/14/26 14:36, Pablo Neira Ayuso wrote: > > On Mon, Sep 14, 2026 at 02:28:49PM +0200, Pablo Neira Ayuso wrote: > > > Hi, > > > > > > On Mon, Sep 14, 2026 at 12:13:50AM +0200, Pablo Neira Ayuso wrote: > > > > On Mon, Sep 14, 2026 at 12:12:16AM +0200, Pablo Neira Ayuso wrote: > > > > > Hi Hauke, > > > > > > > > > > On Wed, Sep 09, 2026 at 06:29:50PM +0200, Hauke Mehrtens wrote: > > > > > > Hi, > > > > > > > > > > > > flow offloading is currently broken in Linux 6.18.45. > > > > > > > > > > > > Since the backport of commit b5964aac51e0 ("netfilter: flowtable: > > > > > > consolidate xmit path") to Linux 6.18.45. This is happening in a router with > > > > > > traffic from wifi to the Ethernet device when mac80211 returns -EOPNOTSUPP. > > > > > > > > > > > > Upstream fixed it in 871df5007eda ("netfilter: flowtable: bail out if > > > > > > forward path cannot be discovered") by not offloading the flow at all. > > > > > > backporting this change looks more complicated. > > > > > > > > > > > > This cam up in a discussion in an OpenWrt PR: > > > > > > https://github.com/openwrt/openwrt/pull/24800 > > > > > > > > > > > > An LLM suggested this change: https://github.com/openwrt/openwrt/pull/24800/changes/394d741e6e76ecd172dbbf1d9ba171e378211734 > > > > > > > > > > Patch went away. > > > > > > > > > > > It seams to work, but I do not understand this part of the code god enough > > > > > > to judge if this is correct. > > > > > > > > > > Could you attach the patch to this email for review? > > > > > > > > I've found it :) > > > > > > > > https://github.com/openwrt/openwrt/commit/d2b53b8043e17087b877bfc2335cbba87dffb4e0 > > > > > > I've proposed the following fix: > > > > > > https://lore.kernel.org/netfilter-devel/20260914122456.1963453-1-pablo@netfilter.org/ > > > > Actually, this v2 should work: > > > > https://lore.kernel.org/netfilter-devel/20260914123334.1964397-1-pablo@netfilter.org/ > > Hi Pablo, > > Thank you for looking into this. > > I think we have to handle DEV_PATH_MTK_WDMA like we do it with DEV_PATH_DSA > in nft_dev_path_info() too. I don't think you can find DEV_PATH_MTK_WDMA from nft_dev_path_info(). There is a story about this: Felix needed a way to expose the MTK SoC capabilities in some way to drivers, he decided to use the .fill_forward_path interface for this purpose. See mtk_flow_get_wdma_info(), it makes a direct call to dev_fill_forward_path() to get the DEV_PATH_MTK_WDMA. Therefore, it is not possible to see DEV_PATH_MTK_WDMA from nft_dev_path_info() because it does not belong there. I suggested a new interface for this but SoC requirements were not clear at the time IIRC. My patch is a workaround, so dev_fill_forward_path() does not fail for this case. > mt7915_net_fill_forward_path() from > drivers/net/wireless/mediatek/mt76/mt7915/main.c could also return > -ENODEV like mac80211 does. > Should we backport 871df5007eda to 6.18 instead? Does 871df5007eda fix the issue for you? If I understood correctly, this simply results in not setting up the flowtable bypass? ie. ethernet to wifi will just fall back to classic forwarding path.