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 6A9C13382E5; Thu, 30 Apr 2026 15:57:55 +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=1777564676; cv=none; b=Gy3U1qWtEKLwtRAa8BDlob0q82dgMhyJB46bQQZdaFrGWoIrr9mypE6o+ekt8LZ9GQrU/jX83nWj4qyhObXkTQmaOUKzdFTjJ4e/AvyHUBvu1vpOxfz7+Yvtu7iSEUWoKYH7bctjaICMAbn8M0Ms6syjm1pBmCwXnjD7uSG96P4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777564676; c=relaxed/simple; bh=NBbW+I5HblCuhQGuDtTWvOWuXyeopGFsbAAGTugsplE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=sprz7xuuvRLlpqOElVcLSXWOXGL42w9uyDWljJeCOVtOrwp8Obs6NbdE64coUZrubSEUnT6BFqJIGbDWExOYrZ7IEEOta3hx8pxGc8LxY6B7o6wIqhrVs0GkUsA0QE22nLHb5mN5yqRtlJ1LKyFNBX+2PwptZUOE4L1LlALMs9k= 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=DDwGkzxI; 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="DDwGkzxI" Received: from netfilter.org (mail-agni [217.70.190.124]) by mail.netfilter.org (Postfix) with UTF8SMTPSA id 2294F60263; Thu, 30 Apr 2026 17:57:53 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=netfilter.org; s=2025; t=1777564673; bh=x8RLS4IOBlLKzzcEugB33op1GEA4JAgsxvw3AAn9dd4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=DDwGkzxIgHG8UjM/zW6YYAp+v/nB8UFgFJAEXQMHudNeizLwQ4b8LOT9gU1p+vhNP huy/AvrirTwKOZ+C3PSzhsccETYGbNrqXB/dfGzOawIDZu0o3X0loIMGR+U6Ad6k/+ 5YyzFaljafsuRgYHrUj+j2W7+N6t8F3KgumfePcJMa0e+fmcLf/8JtlVU5Bd1E07/G jZKt0PipirBeUlyzYtAPgWJ4EHRkvW2cPtMlNimIDBikzLMaAwl4Xn97KzjL32s30e dyYNQ7bnst6Bw6CfU0JJNANHNaZ6XCPQKcu0XM0hTyO2D1YIB8TpYqheeg9tU6VLTH KPFUXFX5SjZBA== Date: Thu, 30 Apr 2026 17:57:50 +0200 From: Pablo Neira Ayuso To: Qingfang Deng Cc: Paolo Abeni , Felix Fietkau , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , David Ahern , Simon Horman , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-ppp@vger.kernel.org Subject: Re: [RFC PATCH net-next v6 1/2] net: pppoe: implement GRO/GSO support Message-ID: References: <20260326081127.61229-1-dqfext@gmail.com> <9d7f1bbc-155d-4c18-bcf7-732ebe4cbf67@redhat.com> 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 Content-Transfer-Encoding: 8bit In-Reply-To: Hi Paolo, On Thu, Apr 30, 2026 at 11:47:57PM +0800, Qingfang Deng wrote: > On Thu, Apr 30, 2026 at 5:34 PM Paolo Abeni wrote: > > > > AFAICS, when the computed len is >= 64K, and the above min() will > > truncate it, later pppoe_rcv() will drop the packet. > > pppoe_rcv() does _not_ drop such packets. > The drop condition is "skb->len < ntohs(ph->length)", not the other way around. > > > > + skb = segs; > > > + do { > > > + phdr = (struct pppoe_hdr *)(skb_mac_header(skb) + nhoff); > > > + len = skb->len - (nhoff + sizeof(*phdr)); > > > + phdr->length = cpu_to_be16(len); > > > + skb->network_header = (u8 *)phdr - skb->head; > > > > I understand is quite late for the following question, but... > > The network headers points to the pppoe hdr. Should it point to the > > actual IP hdr? This is the same with double-tagged-vlan, the network header also points to the inner vlan in the skb payload. Changing this would require to revisit all users in the tree that are already assuming this. > > Why not? A comment in the code or in the commit message would be > > appreciated. > > I'm not sure about the GSO stuff. This code is carried over from > Felix's v3 patch unmodified and I haven't noticed any issues. Maybe he > has the answer. > > FYI, Pablo Neira Ayuso is adding the "inline PPPoE GSO" to Netfilter > flowtable: https://lore.kernel.org/netfilter-devel/20260430055836.223494-2-pablo@netfilter.org/ > to work around missing GSO support in PPPoE driver, prior to this > patch.