linux-kernel - RE: [PATCH net-next 1/1] hyperv: Properly handle checksum offload

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Sat, 26 Apr 2014 02:24:14 +0000
From:	KY Srinivasan <kys@...rosoft.com>
To:	Eric Dumazet <eric.dumazet@...il.com>,
	Stephen Hemminger <stephen@...workplumber.org>
CC:	"davem@...emloft.net" <davem@...emloft.net>,
	"netdev@...r.kernel.org" <netdev@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"devel@...uxdriverproject.org" <devel@...uxdriverproject.org>,
	"olaf@...fle.de" <olaf@...fle.de>,
	"apw@...onical.com" <apw@...onical.com>,
	"jasowang@...hat.com" <jasowang@...hat.com>,
	"stable@...nel.org" <stable@...nel.org>
Subject: RE: [PATCH net-next 1/1]  hyperv: Properly handle checksum offload



> -----Original Message-----
> From: Eric Dumazet [mailto:eric.dumazet@...il.com]
> Sent: Friday, April 25, 2014 6:15 PM
> To: Stephen Hemminger
> Cc: KY Srinivasan; davem@...emloft.net; netdev@...r.kernel.org; linux-
> kernel@...r.kernel.org; devel@...uxdriverproject.org; olaf@...fle.de;
> apw@...onical.com; jasowang@...hat.com; stable@...nel.org
> Subject: Re: [PATCH net-next 1/1] hyperv: Properly handle checksum offload
> 
> On Fri, 2014-04-25 at 17:43 -0700, Stephen Hemminger wrote:
> > On Fri, 25 Apr 2014 11:45:14 -0700
> > "K. Y. Srinivasan" <kys@...rosoft.com> wrote:
> >
> > > @@ -474,6 +477,9 @@ static int netvsc_start_xmit(struct sk_buff *skb,
> struct net_device *net)
> > >  	csum_info = (struct ndis_tcp_ip_checksum_info *)((void *)ppi +
> > >  			ppi->ppi_offset);
> > >
> > > +	ip_hdr(skb)->check = 0;
> > > +	csum_info->transmit.ip_header_checksum = 1;
> > > +
> > >  	if (net_trans_info & (INFO_IPV4 << 16))
> > >  		csum_info->transmit.is_ipv4 = 1;
> > >  	else
> >
> > Linux doesn't need or want IP checksum offload.
> > It will not have any performance gain.
> 
> 
> BTW, was this patch even tested with IPv6 packets ???

No; I only tested this on ipv4.

K. Y
>