From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ian Campbell Subject: Re: [PATCH 2/4] xen-netfront: drop skb when skb->len > 65535 Date: Mon, 18 Mar 2013 14:54:19 +0000 Message-ID: <1363618459.2963.10.camel@zakaz.uk.xensource.com> References: <1363602955-24790-1-git-send-email-wei.liu2@citrix.com> <1363602955-24790-3-git-send-email-wei.liu2@citrix.com> <1363606970.30193.22.camel@zakaz.uk.xensource.com> <1363617642.29093.203.camel@zion.uk.xensource.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: "netdev@vger.kernel.org" , "xen-devel@lists.xen.org" , "konrad.wilk@oracle.com" , "annie.li@oracle.com" To: Wei Liu Return-path: Received: from smtp.eu.citrix.com ([46.33.159.39]:29984 "EHLO SMTP.EU.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750899Ab3CROyW (ORCPT ); Mon, 18 Mar 2013 10:54:22 -0400 In-Reply-To: <1363617642.29093.203.camel@zion.uk.xensource.com> Sender: netdev-owner@vger.kernel.org List-ID: On Mon, 2013-03-18 at 14:40 +0000, Wei Liu wrote: > On Mon, 2013-03-18 at 11:42 +0000, Ian Campbell wrote: > > On Mon, 2013-03-18 at 10:35 +0000, Wei Liu wrote: > > > The `size' field of Xen network wire format is uint16_t, anything bigger than > > > 65535 will cause overflow. > > > > > > Signed-off-by: Wei Liu > > > --- > > > drivers/net/xen-netfront.c | 12 ++++++++++++ > > > 1 file changed, 12 insertions(+) > > > > > > diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c > > > index 5527663..8c3d065 100644 > > > --- a/drivers/net/xen-netfront.c > > > +++ b/drivers/net/xen-netfront.c > > > @@ -547,6 +547,18 @@ static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev) > > > unsigned int len = skb_headlen(skb); > > > unsigned long flags; > > > > > > + /* > > > + * wire format of xen_netif_tx_request only supports skb->len > > > + * < 64K, because size field in xen_netif_tx_request is > > > + * uint16_t. > > > > Is there some field we can set e.g. in struct ethernet_device which > > would stop this from happening? > > > > struct ethernet_device? I could not find it. > > And for struct net_device, I meant struct net_device. > there is no field for this AFAICT. Interesting. Are hardware devices expected to cope with arbitrary sized GSO skbs then I wonder. Ian.