From: Ben Greear <greearb@candelatech.com>
To: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Vijay Pandurangan <vijayp@vijayp.ca>,
netdev <netdev@vger.kernel.org>, Evan Jones <ej@evanjones.ca>,
Cong Wang <cwang@twopensource.com>
Subject: Re: veth regression with "don’t modify ip_summed; doing so treats packets with bad checksums as good."
Date: Thu, 24 Mar 2016 22:13:33 -0700 [thread overview]
Message-ID: <56F4C8FD.7030907@candelatech.com> (raw)
In-Reply-To: <CAM_iQpUaBD-HmHVAcEBCRw38PbecjYk2to+DO9TNkLY93u2_NA@mail.gmail.com>
On 03/24/2016 10:06 PM, Cong Wang wrote:
> On Thu, Mar 24, 2016 at 9:34 PM, Ben Greear <greearb@candelatech.com> wrote:
>>
>>
>> On 03/24/2016 06:44 PM, Vijay Pandurangan wrote:
>>>
>>> Oops, I think my last email didn't go through due to an inadvertent
>>> html attachment from my phone mail client.
>>>
>>> Can you send us a copy of a packet you're sending and/or confirm that
>>> the IP and UDP4 checksums are set correctly in the packet?
>>>
>>> If those are set right, I think we need to read through the networking
>>> code again to see why this is broken...
>>
>>
>> Wireshark decodes the packet as having no checksum errors.
>>
>> I think the contents of the packet is correct, but the 'ip_summed'
>> field is set incorrectly to 'NONE' when transmitting on a raw packet
>> socket.
>
> Yeah, these bugs are all due to the different interpretations of
> ip_summed on TX path and RX path. I think the following patch
> should work, if the comments don't mislead me. Could you give
> it a try?
>
> For the long term, we need to unify the meaning of ip_summed
> on TX path and RX path, or at least translate it in skb_scrub_packet().
I can test this tomorrow, but I think it will not work. I'm not sending raw
IP frames, I'm sending full ethernet frames. Socket is PF_PACKET, SOCK_RAW.
Your patch may still be useful for others though?
Thanks,
Ben
--
Ben Greear <greearb@candelatech.com>
Candela Technologies Inc http://www.candelatech.com
next prev parent reply other threads:[~2016-03-25 5:13 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-24 22:01 veth regression with "don’t modify ip_summed; doing so treats packets with bad checksums as good." Ben Greear
[not found] ` <CAKUBDd91rR7QTwCO6L6ZfRe4fuHw0L5+Zi7qm0uF018dwVGCLg@mail.gmail.com>
2016-03-24 22:57 ` Ben Greear
2016-03-24 23:56 ` Cong Wang
2016-03-25 0:06 ` Ben Greear
2016-03-25 1:11 ` Ben Greear
2016-03-25 1:13 ` Ben Greear
2016-03-25 1:44 ` Vijay Pandurangan
2016-03-25 4:34 ` Ben Greear
2016-03-25 4:41 ` Vijay Pandurangan
2016-03-25 4:45 ` Vijay Pandurangan
2016-03-25 5:07 ` Ben Greear
2016-03-25 5:24 ` Vijay Pandurangan
2016-03-25 14:35 ` Ben Greear
2016-03-25 21:51 ` Vijay Pandurangan
2016-03-25 5:06 ` Cong Wang
2016-03-25 5:13 ` Ben Greear [this message]
2016-03-25 5:33 ` Cong Wang
2016-03-25 16:10 ` Ben Greear
2016-03-25 16:32 ` Cong Wang
2016-03-25 16:45 ` David Miller
2016-03-25 16:44 ` David Miller
2016-03-25 17:14 ` Ben Greear
2016-03-25 19:00 ` David Miller
2016-03-25 20:56 ` Ben Greear
2016-03-25 21:59 ` Vijay Pandurangan
2016-03-25 22:23 ` Ben Greear
2016-03-25 23:03 ` Vijay Pandurangan
2016-03-25 23:46 ` Ben Greear
2016-04-07 15:11 ` Vijay Pandurangan
2016-04-07 18:32 ` Ben Greear
2016-03-25 22:23 ` Cong Wang
2016-03-25 22:16 ` Cong Wang
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