Re: [dpdk-stable] [PATCH] vhost: fix IPv4 csum calculation

Re: [dpdk-stable] [PATCH] vhost: fix IPv4 csum calculation

[Maxime Coquelin]

Hi Flavio,

On 10/24/19 4:28 PM, Flavio Leitner wrote:
> Currently the IPv4 header checksum is calculated including its
> current value, which can be a valid checksum or just garbage.
> In any case, if the original value is not zero, then the result
> is always wrong.
> 
> The IPv4 checksum is defined in RFC791, page 14 says:
>   Header Checksum:  16 bits
> 
>   The checksum algorithm is:
>   The checksum field is the 16 bit one's complement of the one's
>   complement sum of all 16 bit words in the header.  For purposes of
>   computing the checksum, the value of the checksum field is zero.
> 
> Thus force the csum field to always be zero.

I think we need Fixes tag:

Fixes: b08b8cfeb2ae ("vhost: fix IP checksum")
Cc: stable@dpdk.org

Also adding stable in Cc.


> Signed-off-by: Flavio Leitner <fbl@sysclose.org>
> ---
>  lib/librte_vhost/virtio_net.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/lib/librte_vhost/virtio_net.c b/lib/librte_vhost/virtio_net.c
> index eae7825f04..cde7498c76 100644
> --- a/lib/librte_vhost/virtio_net.c
> +++ b/lib/librte_vhost/virtio_net.c
> @@ -445,6 +445,7 @@ virtio_enqueue_offload(struct rte_mbuf *m_buf, struct virtio_net_hdr *net_hdr)
>  
>  		ipv4_hdr = rte_pktmbuf_mtod_offset(m_buf, struct rte_ipv4_hdr *,
>  						   m_buf->l2_len);
> +		ipv4_hdr->hdr_checksum = 0;
>  		ipv4_hdr->hdr_checksum = rte_ipv4_cksum(ipv4_hdr);
>  	}
>  
> 

Other than that:

Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>

I'll add the Fixes tag while applying.

Thanks!
Maxime

[dpdk-stable] [PATCH v2] vhost: fix IPv4 csum calculation

[Flavio Leitner]

Currently the IPv4 header checksum is calculated including its
current value, which can be a valid checksum or just garbage.
In any case, if the original value is not zero, then the result
is always wrong.

The IPv4 checksum is defined in RFC791, page 14 says:
  Header Checksum:  16 bits

  The checksum algorithm is:
  The checksum field is the 16 bit one's complement of the one's
  complement sum of all 16 bit words in the header.  For purposes of
  computing the checksum, the value of the checksum field is zero.

Thus force the csum field to always be zero.

Fixes: b08b8cfeb2ae ("vhost: fix IP checksum")
Cc: stable@dpdk.org

Signed-off-by: Flavio Leitner <fbl@sysclose.org>
---
 lib/librte_vhost/virtio_net.c | 1 +
 1 file changed, 1 insertion(+)

v2:
  CC stable
  Added 'Fixes:' line.

diff --git a/lib/librte_vhost/virtio_net.c b/lib/librte_vhost/virtio_net.c
index eae7825f04..cde7498c76 100644
--- a/lib/librte_vhost/virtio_net.c
+++ b/lib/librte_vhost/virtio_net.c
@@ -445,6 +445,7 @@ virtio_enqueue_offload(struct rte_mbuf *m_buf, struct virtio_net_hdr *net_hdr)
 
 		ipv4_hdr = rte_pktmbuf_mtod_offset(m_buf, struct rte_ipv4_hdr *,
 						   m_buf->l2_len);
+		ipv4_hdr->hdr_checksum = 0;
 		ipv4_hdr->hdr_checksum = rte_ipv4_cksum(ipv4_hdr);
 	}
 
-- 
2.20.1

Re: [dpdk-stable] [PATCH] vhost: fix IPv4 csum calculation

[Flavio Leitner]

On Thu, 24 Oct 2019 16:32:43 +0200
Maxime Coquelin <maxime.coquelin@redhat.com> wrote:

> Hi Flavio,
> 
> On 10/24/19 4:28 PM, Flavio Leitner wrote:
> > Currently the IPv4 header checksum is calculated including its
> > current value, which can be a valid checksum or just garbage.
> > In any case, if the original value is not zero, then the result
> > is always wrong.
> > 
> > The IPv4 checksum is defined in RFC791, page 14 says:
> >   Header Checksum:  16 bits
> > 
> >   The checksum algorithm is:
> >   The checksum field is the 16 bit one's complement of the one's
> >   complement sum of all 16 bit words in the header.  For purposes of
> >   computing the checksum, the value of the checksum field is zero.
> > 
> > Thus force the csum field to always be zero.  
> 
> I think we need Fixes tag:
> 
> Fixes: b08b8cfeb2ae ("vhost: fix IP checksum")
> Cc: stable@dpdk.org
> 
> Also adding stable in Cc.
> 
> 
> > Signed-off-by: Flavio Leitner <fbl@sysclose.org>
> > ---
> >  lib/librte_vhost/virtio_net.c | 1 +
> >  1 file changed, 1 insertion(+)
> > 
> > diff --git a/lib/librte_vhost/virtio_net.c
> > b/lib/librte_vhost/virtio_net.c index eae7825f04..cde7498c76 100644
> > --- a/lib/librte_vhost/virtio_net.c
> > +++ b/lib/librte_vhost/virtio_net.c
> > @@ -445,6 +445,7 @@ virtio_enqueue_offload(struct rte_mbuf *m_buf,
> > struct virtio_net_hdr *net_hdr) 
> >  		ipv4_hdr = rte_pktmbuf_mtod_offset(m_buf, struct
> > rte_ipv4_hdr *, m_buf->l2_len);
> > +		ipv4_hdr->hdr_checksum = 0;
> >  		ipv4_hdr->hdr_checksum = rte_ipv4_cksum(ipv4_hdr);
> >  	}
> >  
> >   
> 
> Other than that:
> 
> Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
> 
> I'll add the Fixes tag while applying.

Not sure if you will send to stable, so I did v2 just in case.
Feel free to drop either one if you took care of those items already.
Thanks!
fbl

Re: [dpdk-stable] [PATCH] vhost: fix IPv4 csum calculation

[Maxime Coquelin]

On 10/24/19 6:31 PM, Flavio Leitner wrote:
> On Thu, 24 Oct 2019 16:32:43 +0200
> Maxime Coquelin <maxime.coquelin@redhat.com> wrote:
> 
>> Hi Flavio,
>>
>> On 10/24/19 4:28 PM, Flavio Leitner wrote:
>>> Currently the IPv4 header checksum is calculated including its
>>> current value, which can be a valid checksum or just garbage.
>>> In any case, if the original value is not zero, then the result
>>> is always wrong.
>>>
>>> The IPv4 checksum is defined in RFC791, page 14 says:
>>>   Header Checksum:  16 bits
>>>
>>>   The checksum algorithm is:
>>>   The checksum field is the 16 bit one's complement of the one's
>>>   complement sum of all 16 bit words in the header.  For purposes of
>>>   computing the checksum, the value of the checksum field is zero.
>>>
>>> Thus force the csum field to always be zero.  
>>
>> I think we need Fixes tag:
>>
>> Fixes: b08b8cfeb2ae ("vhost: fix IP checksum")
>> Cc: stable@dpdk.org
>>
>> Also adding stable in Cc.
>>
>>
>>> Signed-off-by: Flavio Leitner <fbl@sysclose.org>
>>> ---
>>>  lib/librte_vhost/virtio_net.c | 1 +
>>>  1 file changed, 1 insertion(+)
>>>
>>> diff --git a/lib/librte_vhost/virtio_net.c
>>> b/lib/librte_vhost/virtio_net.c index eae7825f04..cde7498c76 100644
>>> --- a/lib/librte_vhost/virtio_net.c
>>> +++ b/lib/librte_vhost/virtio_net.c
>>> @@ -445,6 +445,7 @@ virtio_enqueue_offload(struct rte_mbuf *m_buf,
>>> struct virtio_net_hdr *net_hdr) 
>>>  		ipv4_hdr = rte_pktmbuf_mtod_offset(m_buf, struct
>>> rte_ipv4_hdr *, m_buf->l2_len);
>>> +		ipv4_hdr->hdr_checksum = 0;
>>>  		ipv4_hdr->hdr_checksum = rte_ipv4_cksum(ipv4_hdr);
>>>  	}
>>>  
>>>   
>>
>> Other than that:
>>
>> Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
>>
>> I'll add the Fixes tag while applying.
> 
> Not sure if you will send to stable, so I did v2 just in case.
> Feel free to drop either one if you took care of those items already.
> Thanks!
> fbl
> 
> 

I synced with Ferruh, and he proposed to pick it directly for -rc1.

Thanks!
Maxime

Re: [dpdk-stable] [PATCH v2] vhost: fix IPv4 csum calculation

[Ferruh Yigit]

On 10/24/2019 5:29 PM, Flavio Leitner wrote:
> Currently the IPv4 header checksum is calculated including its
> current value, which can be a valid checksum or just garbage.
> In any case, if the original value is not zero, then the result
> is always wrong.
> 
> The IPv4 checksum is defined in RFC791, page 14 says:
>   Header Checksum:  16 bits
> 
>   The checksum algorithm is:
>   The checksum field is the 16 bit one's complement of the one's
>   complement sum of all 16 bit words in the header.  For purposes of
>   computing the checksum, the value of the checksum field is zero.
> 
> Thus force the csum field to always be zero.
> 
> Fixes: b08b8cfeb2ae ("vhost: fix IP checksum")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Flavio Leitner <fbl@sysclose.org>

Applied to dpdk-next-net/master, thanks.