From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 46F601DCB09; Fri, 6 Jun 2025 17:09:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749229747; cv=none; b=D8s9pqluqKyZ0NIMvBNAa7I2vqCqaWSkqtIfIg+7sp7YaJgTkOnwY/JdZw5Qr4YmTh9fm1MnEDDI6cEejXzRr+XyL2RxDvVekgkQJ/gwzq3bC1XVxPYJK28AkdcO5E26k+LySiCY8B4SEa4aFhu8wxucjV34VIiHjZ3QXRshgFA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749229747; c=relaxed/simple; bh=4wz8BRL+n/MQpnQHEz1U+NXu/OCcRQ/pOsQCQAPqlAI=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=kgiDMMgD5QpP5MSExPltXYoFn1dWsuUa8LtemEvcfDsxmY/JQ1GJJBicyKhGVXunOA2lQcJh5yIENPMtE+I1ZVm4MHwDKSzwbB3cnLvJWnwmiaNX7Dc7aAas8CwhrOp2MKAx/XardEaJubaC4BWw3zp/NyEbC9NQmU0eVNwy9G4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=FkVQGYSR; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="FkVQGYSR" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DCB8CC4CEEB; Fri, 6 Jun 2025 17:09:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1749229746; bh=4wz8BRL+n/MQpnQHEz1U+NXu/OCcRQ/pOsQCQAPqlAI=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=FkVQGYSRuXJbgU/ZvU4cjb0hsP0JhjabswEuhsC0WVB27AEO4SbD2LLhSpxGpB1sj o5J7oUop+Z6BSwmhxLcg7pZezRREWJ79lAu6QF3XAaMfyh9N6VfC1dLdQF5sc4JjgR LQIXK1maq6eNJ8WdHO+jZ0mH2Gg9fIFLEoCtqvgzCey4dfLKiKLGUeWMXTkF2qKC8B Y7bTraeCcD7HIYnYSrrhletVerTY00xeygExH48KkubEcjbOXn/GINyUyuTG1w2ojP IV+9uG9KZbxCr6YnPisKEAfMUyCPVJmqDMxMr8GF66d8QVetCKWJsAsQ+cZerv8ZrW CD6HLTh03QWNA== Date: Fri, 6 Jun 2025 10:09:04 -0700 From: Jakub Kicinski To: Willem de Bruijn Cc: Maciej =?UTF-8?B?xbtlbmN6eWtvd3NraQ==?= , davem@davemloft.net, netdev@vger.kernel.org, edumazet@google.com, pabeni@redhat.com, andrew+netdev@lunn.ch, horms@kernel.org, martin.lau@linux.dev, daniel@iogearbox.net, john.fastabend@gmail.com, eddyz87@gmail.com, sdf@fomichev.me, haoluo@google.com, willemb@google.com, william.xuanziyang@huawei.com, alan.maguire@oracle.com, bpf@vger.kernel.org Subject: Re: [PATCH net] net: clear the dst when changing skb protocol Message-ID: <20250606100904.668aa3f4@kernel.org> In-Reply-To: <68430f86f651_266eaf294ab@willemb.c.googlers.com.notmuch> References: <20250604210604.257036-1-kuba@kernel.org> <20250605062234.1df7e74a@kernel.org> <20250605070131.53d870f6@kernel.org> <684231d3bb907_208a5f2945f@willemb.c.googlers.com.notmuch> <20250605173142.1c370506@kernel.org> <68430f86f651_266eaf294ab@willemb.c.googlers.com.notmuch> Precedence: bulk X-Mailing-List: netdev@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 Fri, 06 Jun 2025 11:55:50 -0400 Willem de Bruijn wrote: > I would drop on every program that calls bpf_skb_adjust_room() or > bpf_skb_change_proto(). I think @maze covered it well, not all adjust_room calls matter to L3, they may be adjusting L2. I don't feel like blanket dst discard is either always correct or necessarily sufficient (when rerouting the packet without adjusting length). Let me respond to him with the draft patch..