netdev - Re: suspicius csum initialization in vmxnet3_rx

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Message-ID: <20180531233227.GA6985@neilslaptop.think-freely.org>
Date:   Thu, 31 May 2018 19:32:27 -0400
From:   Neil Horman <nhorman@...driver.com>
To:     Ronak Doshi <doshir@...are.com>
Cc:     Paolo Abeni <pabeni@...hat.com>, Guolin Yang <gyang@...are.com>,
        Boon Ang <bang@...are.com>, Louis Luo <llouis@...are.com>,
        netdev@...r.kernel.org
Subject: Re: suspicius csum initialization in vmxnet3_rx_csum

On Thu, May 31, 2018 at 11:02:34AM -0700, Ronak Doshi wrote:
> 
> On Wed, 30 May 2018, Paolo Abeni wrote:
> 
> > Hi,
> > 
> > On Thu, 2018-05-24 at 21:48 +0000, Guolin Yang wrote:
> > > Yes, that code  is not correct, we should fix that code
> > 
> > Did you have any chance to address the issue and/or to give a more in-
> > deepth look to the change proposed in my initial email?
> >  
> Hi Paolo,
> 
> Can you provide the esx build you are using? It can be found using 
> "vmware -vl" on ESX host.
> 
> Did you try your proposed fix and did it work? Are you sure the packet
> hits the below if block and not the else block? I still don't think the
> ICMP packet will go through the below if block.
> 
>    if (gdesc->rcd.csum) {
> 	skb->csum = htons(gdesc->rcd.csum);
> 	skb->ip_summed = CHECKSUM_PARTIAL;
>    } else {
> 	skb_checksum_none_assert(skb);
>    }
> 
> The vmxnet3 emulation does not calculate rcd.csum for ICMP packet and
> hence should go through the else block i.e. checksum none.
> 
What packet types will rcd.csum be set for?
Neil

> Thanks,
> Ronak
>