From: Anton Ivanov <anton.ivanov@cambridgegreys.com>
To: Jason Wang <jasowang@redhat.com>, netdev@vger.kernel.org
Cc: linux-um@lists.infradead.org, mst@redhat.com,
virtualization@lists.linux-foundation.org
Subject: Re: [PATCH] virtio: Work around frames incorrectly marked as gso
Date: Tue, 11 Feb 2020 07:42:37 +0000 [thread overview]
Message-ID: <918222d9-816a-be70-f8af-b8dfcb586240@cambridgegreys.com> (raw)
In-Reply-To: <f78bfe6e-2ffc-3734-9618-470f1afea0c6@redhat.com>
On 11/02/2020 02:51, Jason Wang wrote:
>
> On 2020/2/11 上午12:55, Anton Ivanov wrote:
>>
>>
>> On 09/12/2019 10:48, anton.ivanov@cambridgegreys.com wrote:
>>> From: Anton Ivanov <anton.ivanov@cambridgegreys.com>
>>>
>>> Some of the frames marked as GSO which arrive at
>>> virtio_net_hdr_from_skb() have no GSO_TYPE, no
>>> fragments (data_len = 0) and length significantly shorter
>>> than the MTU (752 in my experiments).
>>>
>>> This is observed on raw sockets reading off vEth interfaces
>>> in all 4.x and 5.x kernels I tested.
>>>
>>> These frames are reported as invalid while they are in fact
>>> gso-less frames.
>>>
>>> This patch marks the vnet header as no-GSO for them instead
>>> of reporting it as invalid.
>>>
>>> Signed-off-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>
>>> ---
>>> include/linux/virtio_net.h | 8 ++++++--
>>> 1 file changed, 6 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/include/linux/virtio_net.h b/include/linux/virtio_net.h
>>> index 0d1fe9297ac6..d90d5cff1b9a 100644
>>> --- a/include/linux/virtio_net.h
>>> +++ b/include/linux/virtio_net.h
>>> @@ -112,8 +112,12 @@ static inline int virtio_net_hdr_from_skb(const
>>> struct sk_buff *skb,
>>> hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
>>> else if (sinfo->gso_type & SKB_GSO_TCPV6)
>>> hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
>>> - else
>>> - return -EINVAL;
>>> + else {
>>> + if (skb->data_len == 0)
>>> + hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE;
>>> + else
>>> + return -EINVAL;
>>> + }
>>> if (sinfo->gso_type & SKB_GSO_TCP_ECN)
>>> hdr->gso_type |= VIRTIO_NET_HDR_GSO_ECN;
>>> } else
>>>
>>
>> ping.
>>
>
> Do you mean gso_size is set but gso_type is not? Looks like a bug
> elsewhere.
>
> Thanks
>
>
Yes.
I could not trace it where it is coming from.
I see it when doing recvmmsg on raw sockets in the UML vector network
drivers.
--
Anton R. Ivanov
Cambridgegreys Limited. Registered in England. Company Number 10273661
https://www.cambridgegreys.com/
next prev parent reply other threads:[~2020-02-11 7:42 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-09 10:48 [PATCH] virtio: Work around frames incorrectly marked as gso anton.ivanov
2019-12-09 10:54 ` Johannes Berg
2020-02-10 16:55 ` Anton Ivanov
2020-02-11 2:51 ` Jason Wang
2020-02-11 7:42 ` Anton Ivanov [this message]
2020-02-11 10:37 ` Michael S. Tsirkin
2020-02-12 10:03 ` Anton Ivanov
2020-02-12 10:19 ` Michael S. Tsirkin
2020-02-12 11:17 ` Anton Ivanov
2020-02-12 17:38 ` Anton Ivanov
2020-02-13 3:31 ` Jason Wang
2020-02-13 11:07 ` Anton Ivanov
2020-02-13 10:00 ` Michael S. Tsirkin
2020-02-13 11:12 ` Anton Ivanov
2020-02-13 13:12 ` Michael S. Tsirkin
2020-02-13 15:44 ` Eric Dumazet
2020-02-13 15:53 ` Michael S. Tsirkin
2020-02-13 16:23 ` Anton Ivanov
2020-02-13 16:37 ` Michael S. Tsirkin
2020-02-20 7:58 ` Michael S. Tsirkin
2020-02-20 19:33 ` Anton Ivanov
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