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From: Johannes Berg <johannes-cdvu00un1VgdHxzADdlk8Q@public.gmane.org>
To: Eric Dumazet <eric.dumazet-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Cc: netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	linux-wireless
	<linux-wireless-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
Subject: Re: IPv6-UDP 0x0000 checksum
Date: Thu, 26 Jan 2017 15:49:24 +0100	[thread overview]
Message-ID: <1485442164.14760.11.camel@sipsolutions.net> (raw)
In-Reply-To: <1485441942.5145.131.camel-XN9IlZ5yJG9HTL0Zs8A6p+yfmBU6pStAUsxypvmhUTTZJqsBc5GL+g@public.gmane.org> (sfid-20170126_154545_190303_B1FB80BF)

On Thu, 2017-01-26 at 06:45 -0800, Eric Dumazet wrote:
> On Thu, 2017-01-26 at 14:49 +0100, Johannes Berg wrote:
> 
> > Oops, sorry - receive. We can only indicate "CHECKSUM_UNNECESSARY",
> > nothing more advanced right now, but right now we'd indicate that
> > if
> > the packet had 0x0000 in the checksum field, but should've had
> > 0xffff.
> > 
> > On TX I believe we actually do in HW exactly what your patch just
> > did.
> 
> Can you describe the visible effects of this problem ?
> 
> Is that because of a conversion we might do later to
> CHECKSUM_COMPLETE ?

Unfortunately, I haven't been able to actually test this yet. I also
didn't find the code that would drop frames with CSUM 0 either, so I'm
thinking - for now - that if all the csum handling is skipped, dropping
0 csum frames would also be, and then we'd accept a frame we should
actually have dropped.

I'll go test this I guess :)

Any pointers to where 0 csum frames are dropped?

johannes

  parent reply	other threads:[~2017-01-26 14:49 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-01-26 13:27 IPv6-UDP 0x0000 checksum Johannes Berg
2017-01-26 13:44 ` Eric Dumazet
2017-01-26 13:49   ` Johannes Berg
     [not found]     ` <1485438546.14760.7.camel-cdvu00un1VgdHxzADdlk8Q@public.gmane.org>
2017-01-26 14:45       ` Eric Dumazet
     [not found]         ` <1485441942.5145.131.camel-XN9IlZ5yJG9HTL0Zs8A6p+yfmBU6pStAUsxypvmhUTTZJqsBc5GL+g@public.gmane.org>
2017-01-26 14:49           ` Johannes Berg [this message]
     [not found]             ` <1485442164.14760.11.camel-cdvu00un1VgdHxzADdlk8Q@public.gmane.org>
2017-01-26 15:24               ` Eric Dumazet
     [not found]                 ` <1485444276.5145.133.camel-XN9IlZ5yJG9HTL0Zs8A6p+yfmBU6pStAUsxypvmhUTTZJqsBc5GL+g@public.gmane.org>
2017-01-26 15:27                   ` Eric Dumazet
     [not found]                     ` <1485444476.5145.136.camel-XN9IlZ5yJG9HTL0Zs8A6p+yfmBU6pStAUsxypvmhUTTZJqsBc5GL+g@public.gmane.org>
2017-01-26 15:36                       ` Johannes Berg
2017-01-26 15:32                 ` Johannes Berg

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