From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 9132B3769E0; Fri, 14 Aug 2026 21:09:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786741796; cv=none; b=gwUktn7WWlXbVhAGDrXQyBk2CUTF2B8TbJX6H3uKqC1RNq6vUIHAGUJrLwxdU63MEp+UdpSkVtMpowguYDZINUsMfw+JtTi8TC/aUq0S7veygfj867OzWqkUHitwG1hm+25zMON7g4MpuNGPab8kzF4G2mZ0KxAFl/OPI83zniA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786741796; c=relaxed/simple; bh=3JsTsQTVswbODlI5hArocHEAzLiWEulnRNOtAK6WZxk=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=uDVJXbO3amucTtfyFv47GzD+gZ2zFBBxArpDbGyGl8nfpO3FDy+kQKMv3U08YCDpGTHGZE/b2Fm2+hmhr5bcy4xgPFNihkPnP4axkXLDfmmhamvjzP6yc53JiMsIOG0ggieBY9xkpx5wXQpqdudLnaoSOoiGnmGmnLa3q3BFhDA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=PkHN2VsN; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="PkHN2VsN" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 217421F000E9; Fri, 14 Aug 2026 21:09:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1786741793; bh=jszSB1aALdMUq+st4+V+S0JozFvNf+7milePihRupnQ=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=PkHN2VsN3pdSWGQKScS2rxJR2VrzjKf8zG1MmZr/1FPXqEDAcRyR+BBa447HhF26V dkFNlrSOclL3sUoA2QJS8LYocgxezPOxuu0U/eL6mu6/3k05j935NoTlRzQLNvl/NF GedW68zI75btWCHd9e0Yu/e81P3aqT3cRsFVohGLM4y2syd/M9aro5phf48C09NwXC gN/TDBtTpK4PEDk59riB3mhCNquUQLm4bLBS4ILbE5NoQXR1+9vnPoGVo0j63XKpAo mBeJj10woH1rxHRM4qZ4BG50Zt5O+LVh93S1vKCyZujzg+EsC9N2xWI7g/fpUFhDLm LV4u0tvq28ceA== Date: Fri, 14 Aug 2026 14:09:52 -0700 From: Jakub Kicinski To: Jiayuan Chen Cc: netdev@vger.kernel.org, Kenneth Lee , "David S. Miller" , Eric Dumazet , Paolo Abeni , Simon Horman , Alexei Starovoitov , Daniel Borkmann , Jesper Dangaard Brouer , John Fastabend , Stanislav Fomichev , Kuniyuki Iwashima , Hangbin Liu , Krishna Kumar , Martin Karsten , Toke =?UTF-8?B?SMO4aWxhbmQtSsO4cmdlbnNlbg==?= , Martin Willi , linux-kernel@vger.kernel.org, bpf@vger.kernel.org Subject: Re: [PATCH net-next] net: xdp: don't assume an Ethernet header in generic XDP Message-ID: <20260814140952.12d3f43f@kernel.org> In-Reply-To: <20260813113229.381136-1-jiayuan.chen@linux.dev> References: <20260813113229.381136-1-jiayuan.chen@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Thu, 13 Aug 2026 19:32:24 +0800 Jiayuan Chen wrote: > Refusing to attach XDP to L3 devices instead would not help: mac_len is a > property of the skb, not of the netdev, so an ARPHRD_ETHER device can see > mac_len == 0 too. Let's try. There is no native XDP on any non-ether device, making generic xdp work on those is silly. Just attach the BPF in TC. AI says that one example for mac_len=0 packet on ether device is IP mcast loopback, which should not go via generic XDP in the first place. > Fixes: 22b6034323fd ("net, xdp: Update pkt_type if generic XDP changes unicast MAC") Please don't send fixes to net-next :| -- pw-bot: cr