From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4B9B6C282DD for ; Tue, 7 Jan 2020 19:45:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 22A1724677 for ; Tue, 7 Jan 2020 19:45:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=lunn.ch header.i=@lunn.ch header.b="ej2rYTh/" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728761AbgAGTpj (ORCPT ); Tue, 7 Jan 2020 14:45:39 -0500 Received: from vps0.lunn.ch ([185.16.172.187]:51266 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728748AbgAGTpj (ORCPT ); Tue, 7 Jan 2020 14:45:39 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lunn.ch; s=20171124; h=In-Reply-To:Content-Type:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Sender:Reply-To:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=fLI3vbFuQeo6MNH7rDpLpEc7V3nP+2LA0KTZKh7sdb0=; b=ej2rYTh/Mm4onKMAJCnljY8y6y yPFbdNCvIAZxLpwpC2uA1BNLJR9pSOcK6m1Fm1mh05w7wjdDK5pgOUO7OYu+VYxLMS1X5YfY7WCu9 ZMTJLnMulzTO/UYS0hlxo4euE/9sCWTJ8PRfVUXtV+C5bkAIi7jKVZPdIdXC0NK+s3io=; Received: from andrew by vps0.lunn.ch with local (Exim 4.93) (envelope-from ) id 1iounI-0004k6-Nk; Tue, 07 Jan 2020 20:45:36 +0100 Date: Tue, 7 Jan 2020 20:45:36 +0100 From: Andrew Lunn To: Shannon Nelson Cc: netdev@vger.kernel.org, davem@davemloft.net Subject: Re: [PATCH v2 net-next 3/4] ionic: restrict received packets to mtu size Message-ID: <20200107194536.GB16895@lunn.ch> References: <20200107034349.59268-1-snelson@pensando.io> <20200107034349.59268-4-snelson@pensando.io> <20200107130949.GA23819@lunn.ch> <112c6fd3-6565-e88a-dde5-520770d9f024@pensando.io> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <112c6fd3-6565-e88a-dde5-520770d9f024@pensando.io> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org > Hi Andrew, > Hi Shannon > In my experience the driver typically tells the NIC about the current > max_frame size (e.g. MTU + ETH_HLEN), the NIC only copies max_frame bytes, > and the NIC returns an error indication on a packets that had more than > max_frame. Having played around with a few different NICs for DSA, it seems more like 75% don't care about the 'MRU' and will happily accept bigger frames. Anyway, it does not hurt to drop received frames bigger than what you can transmit. Reviewed-by: Andrew Lunn Andrew