From mboxrd@z Thu Jan 1 00:00:00 1970 From: Russell King Subject: Re: 2.6.25: Weird IPv4 stack behaviour, IPv6 is fine Date: Mon, 28 Apr 2008 13:00:22 +0100 Message-ID: <20080428120022.GB1011@flint.arm.linux.org.uk> References: <48157685.1040709@openvz.org> <20080428093130.GA1011@flint.arm.linux.org.uk> <20080428101835.GA13522@flint.arm.linux.org.uk> <20080428.033022.166259760.davem@davemloft.net> Mime-Version: 1.0 Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=arm.linux.org.uk; s=caramon; h=Date:From:To:Cc:Subject: Message-ID:References:Mime-Version:Content-Type:In-Reply-To: Sender; bh=7M/xzutNPg908crxOxAIc/6QQGFVw0BiyZtjEWdKWHU=; b=IorFw U5cLkO353zN7/8/8VmFWkmDNPvuiPAyyQbv/gJJSzZLgy/kOC9eMUvhOK79kzoEd 6Lh4onhY2gH08D6np044vB90V1NcsxhDQctehljZvLqS6Qk62e21k798CU/qY3CT eeNtuDLXvh+rh1AeWNf/lRv4h4i/VgHb0vVVj0= Content-Disposition: inline In-Reply-To: <20080428.033022.166259760.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: David Miller Cc: xemul@openvz.org, netdev@vger.kernel.org, netfilter@vger.kernel.org On Mon, Apr 28, 2008 at 03:30:22AM -0700, David Miller wrote: > From: Russell King > Date: Mon, 28 Apr 2008 11:18:35 +0100 > > > Further to this, it's looking like there's a nf_conntrack issue. Having > > placed similar printks in the netfilter code, I see the ipv4_confirm() > > hook normally returning 1 (NF_ACCEPT), but then decides to return 0 > > (NF_DROP) and no ping replies. > > There's already been a report about specific hashing problems with > conntrack on ARM. It has something to do with how structures are > padding on ARM combined with the following patch made by Patrick: > > commit 0794935e21a18e7c171b604c31219b60ad9749a9 > Author: Patrick McHardy > Date: Thu Jan 31 04:40:52 2008 -0800 Yup, reverting that appears to fix the problem. Looking at the structure, it will contain two bytes of padding in the 'u' union and another two bytes in the 'dst' structure. I suspect there'll be objections to packing the structure, in which case what's the permanent fix? -- Russell King