From: Johannes Berg <johannes@sipsolutions.net>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: netdev@vger.kernel.org, linux-wireless <linux-wireless@vger.kernel.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@edumazet-glaptop3.roam.corp.google.com> (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
WARNING: multiple messages have this Message-ID (diff)
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
next prev parent reply other threads:[~2017-01-26 14:49 UTC|newest]
Thread overview: 14+ 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
2017-01-26 14:45 ` Eric Dumazet
2017-01-26 14:45 ` Eric Dumazet
2017-01-26 14:49 ` Johannes Berg [this message]
2017-01-26 14:49 ` Johannes Berg
2017-01-26 15:24 ` Eric Dumazet
2017-01-26 15:24 ` Eric Dumazet
2017-01-26 15:27 ` Eric Dumazet
2017-01-26 15:27 ` Eric Dumazet
2017-01-26 15:36 ` Johannes Berg
2017-01-26 15:36 ` Johannes Berg
2017-01-26 15:32 ` Johannes Berg
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