From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH v2] net/hyperv: fix the issue that large packets be dropped under bridge Date: Thu, 02 Feb 2012 14:22:08 -0500 (EST) Message-ID: <20120202.142208.1717482462537460304.davem@davemloft.net> References: Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: haiyangz@microsoft.com, kys@microsoft.com, netdev@vger.kernel.org To: weiyj.lk@gmail.com Return-path: Received: from shards.monkeyblade.net ([198.137.202.13]:44740 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932629Ab2BBTWM (ORCPT ); Thu, 2 Feb 2012 14:22:12 -0500 In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: From: Wei Yongjun Date: Thu, 2 Feb 2012 14:17:23 +0800 > From: Wei Yongjun > > The packets with size larger than 1452 will be dropped by bridge > which with two hyperv netdevice ports. This cause by hyperv netvsc > driver always copy the trailer padding to the data packet, and then > the skb received from netdevice may include wrong skb->len (20 bytes > larger than the real size normally). The captured packet may like > this: > > Ethernet II, Src: Microsof_00:00:07 (00:15:5d:00:00:07), > Dst: HewlettP_00:00:4e (00:1f:29:00:00:4e) > Destination: HewlettP_e6:00:4e (00:1f:29:00:00:4e) > Source: Microsof_f6:6d:07 (00:15:5d:f6:6d:07) > Type: IP (0x0800) > Trailer: 1415161718191A1B1C1D1E1F20212223 > Frame check sequence: 0x24252627 [incorrect, should be 0x7c2e5a5e] > > The following command help to reproduction it, and the ping ICMP > packets will be dropped by bridge. > $ ping ip -s 1453 > > This patch fixed it by removing the trailer padding from the data > packet. > > Signed-off-by: Wei Yongjun Applied.