From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Greear Subject: Re: veth regression with =?UTF-8?B?ImRvbuKAmXQgbW9kaWZ5IGlwX3N1bQ==?= =?UTF-8?B?bWVkOyBkb2luZyBzbyB0cmVhdHMgcGFja2V0cyB3aXRoIGJhZCBjaGVja3N1bXM=?= =?UTF-8?B?IGFzIGdvb2QuIg==?= Date: Thu, 24 Mar 2016 22:07:10 -0700 Message-ID: <56F4C77E.1010608@candelatech.com> References: <56F463D6.7080406@candelatech.com> <56F4810A.9060904@candelatech.com> <56F49036.8050902@candelatech.com> <56F490B2.3090603@candelatech.com> <56F4BFF1.8010806@candelatech.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: Cong Wang , netdev , Evan Jones , Cong Wang To: Vijay Pandurangan Return-path: Received: from mail2.candelatech.com ([208.74.158.173]:58583 "EHLO mail2.candelatech.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751362AbcCYFHN (ORCPT ); Fri, 25 Mar 2016 01:07:13 -0400 In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: On 03/24/2016 09:45 PM, Vijay Pandurangan wrote: > Actually, maybe they should be set to CHECKSUM_PARTIAL if we want veth > to drop the packets if they have bad checksums before they hit the > application level. VETH is pretty special in that when you transmit a frame on one device, it's pair receives it, and unless there is RAM corruption or bugs in the kernel, then it cannot be corrupted. But, if you are routing frames from the network to veth devices, then the original packet could be corrupted, as described in your patch. Probably the right behaviour is to keep the old logic for packets originating from sockets, at least. I am not sure of a good way to implement that. As for testing, I am not sure. Probably you have to make a good effort and then just deal with fallout like what I found. I would guess that any of us who have ever written an interesting patch have also written an interesting bug! Thanks, Ben -- Ben Greear Candela Technologies Inc http://www.candelatech.com