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 8E8A81465BE for ; Thu, 8 Aug 2024 09:23:26 +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=1723109007; cv=none; b=cNLlv99zQ7b3RYUmjIFrRNrFfy9ozIwbvoCUqEZw0YwsRtZjaMWPavODf94bMj18fcRH7sWQ2yxmKgE9hTZoZVBNm3KOgP2bbQfrF8cOLWJqb906N4EPfoB8ZxvQAWOkM09ZZGB36T39cCrhoPKkSlXvnC9iXeEF/zvjaKdnb3Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723109007; c=relaxed/simple; bh=iX1EZO3yB15rqCO9EMHQKda+8yUGAiCcnTG3M9Qyztc=; h=From:To:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=nqUZ1YLHHL9UnvMX/g4YERYFBRDgKU0sBM60JwXE6VjpCXY3I7xMST4F4x+eHjtaFnUeFttRwBFpUS6RQ+oyWoViFsFMzMkwMIR5eehH329di7sKT91kryQePm+CMfNRNQMJKtaVKugaf/6cIXLXz7M5WDzcoAwj8wYVd/K/2HA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=bt17wLI5; 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="bt17wLI5" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DA9CCC32782; Thu, 8 Aug 2024 09:23:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1723109006; bh=iX1EZO3yB15rqCO9EMHQKda+8yUGAiCcnTG3M9Qyztc=; h=From:To:Subject:In-Reply-To:References:Date:From; b=bt17wLI5ZTjvggrJW8j/SRhYSu7B2gtrSvaMInrouW025Wn7XladRSdmxvEob2OvS T4tIJPbE5+0MA4GM2Ayr7/DnCpEgwipV8lpsFo9nQ9ilCHJO5aB0ubR7dC5Zzhr6N0 s4suCXQ2R/LrDBgLxYkGAL/OfZKnklM7iJnxbKDkJQjAyJkg2Owm69qoFm/jztCFwh MZddzNyioWOOPGVRfKhZhGs9fXZOCgsFAb4ApyB0Jr2qlHHntDtt7+GA38IEg2cQZj /V33K+puHZnth0eSXcARZdzDSv+Fiyp8k2KSzqq9xkMHFhBUocAu9z9+U5cwx+bIKc PRRaRc93M/wYQ== Received: by alrua-x1.borgediget.toke.dk (Postfix, from userid 1000) id 863A514AD648; Thu, 08 Aug 2024 11:23:22 +0200 (CEST) From: Toke =?utf-8?Q?H=C3=B8iland-J=C3=B8rgensen?= To: Duan Jiong , netdev@vger.kernel.org Subject: Re: [PATCH v3] veth: Drop MTU check when forwarding packets In-Reply-To: <20240808070428.13643-1-djduanjiong@gmail.com> References: <20240808070428.13643-1-djduanjiong@gmail.com> X-Clacks-Overhead: GNU Terry Pratchett Date: Thu, 08 Aug 2024 11:23:22 +0200 Message-ID: <87v80bpdv9.fsf@toke.dk> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain Duan Jiong writes: > When the mtu of the veth card is not the same at both ends, there > is no need to check the mtu when forwarding packets, and it should > be a permissible behavior to allow receiving packets with larger > mtu than your own. Erm, huh? The MTU check is against the receiving interface, so AFAICT your patch just disables MTU checking entirely for veth devices, which seems ill-advised. What's the issue you are trying to fix, exactly? -Toke