Non-working TX IP checksum offload

Non-working TX IP checksum offload

[Angela Czubak]

Hi,

I have some difficulties using ip checksum tx offload capabilities - I 
think I set everything as advised by the API documentation, but 
unfortunately the packet leaves the interface with its ip checksum still 
being zero (it reaches its destination).

What I do is:
buffer->ol_flags |= PKT_TX_IP_CKSUM|PKT_TX_IPV4;
ip_header->hdr_checksum = 0;
buffer->l3_len = sizeof(struct ipv4_hdr);
buffer->l2_len = sizeof(struct ether_hdr);

In L4 there's UDP, which checksum is zeroed if that matters.

Is there something I am missing? The NIC is Intel Corporation Ethernet 
Controller X710 for 10GbE SFP+ (rev 01).

What is more, is there any particular reason for assuming in 
i40e_xmit_pkts that offloading checksums is unlikely (I mean the line no 
1307 "if (unlikely(ol_flags & I40E_TX_CKSUM_OFFLOAD_MASK))" at 
dpdk-2.0.0/lib/librte_pmd_i40e/i40e_rxtx.c)?

Regards,
Angela

Re: Non-working TX IP checksum offload

[Andriy Berestovskyy]

Cześć Angela,
Make sure your NIC is configured properly as described in this thread:
http://dpdk.org/ml/archives/dev/2015-May/018096.html

Andriy

On Fri, Jul 17, 2015 at 4:23 PM, Angela Czubak <ACzubak@pl.ibm.com> wrote:
> Hi,
>
> I have some difficulties using ip checksum tx offload capabilities - I
> think I set everything as advised by the API documentation, but
> unfortunately the packet leaves the interface with its ip checksum still
> being zero (it reaches its destination).
>
> What I do is:
> buffer->ol_flags |= PKT_TX_IP_CKSUM|PKT_TX_IPV4;
> ip_header->hdr_checksum = 0;
> buffer->l3_len = sizeof(struct ipv4_hdr);
> buffer->l2_len = sizeof(struct ether_hdr);
>
> In L4 there's UDP, which checksum is zeroed if that matters.
>
> Is there something I am missing? The NIC is Intel Corporation Ethernet
> Controller X710 for 10GbE SFP+ (rev 01).
>
> What is more, is there any particular reason for assuming in
> i40e_xmit_pkts that offloading checksums is unlikely (I mean the line no
> 1307 "if (unlikely(ol_flags & I40E_TX_CKSUM_OFFLOAD_MASK))" at
> dpdk-2.0.0/lib/librte_pmd_i40e/i40e_rxtx.c)?
>
> Regards,
> Angela



-- 
Andriy Berestovskyy

Re: Non-working TX IP checksum offload

[Angela Czubak]

Hi Andriy,

thank you, that solved it.

Regards,
Angela

Andriy Berestovskyy <aber@semihalf.com> wrote on 07/17/2015 04:37:45 PM:

> From: Andriy Berestovskyy <aber@semihalf.com>
> To: Angela Czubak/Poland/Contr/IBM@IBMPL, 
> Cc: dev@dpdk.org
> Date: 07/17/2015 04:38 PM
> Subject: Re: [dpdk-dev] Non-working TX IP checksum offload
> 
> Cześć Angela,
> Make sure your NIC is configured properly as described in this thread:
> http://dpdk.org/ml/archives/dev/2015-May/018096.html
> 
> Andriy
> 
> On Fri, Jul 17, 2015 at 4:23 PM, Angela Czubak <ACzubak@pl.ibm.com> 
wrote:
> > Hi,
> >
> > I have some difficulties using ip checksum tx offload capabilities - I
> > think I set everything as advised by the API documentation, but
> > unfortunately the packet leaves the interface with its ip checksum 
still
> > being zero (it reaches its destination).
> >
> > What I do is:
> > buffer->ol_flags |= PKT_TX_IP_CKSUM|PKT_TX_IPV4;
> > ip_header->hdr_checksum = 0;
> > buffer->l3_len = sizeof(struct ipv4_hdr);
> > buffer->l2_len = sizeof(struct ether_hdr);
> >
> > In L4 there's UDP, which checksum is zeroed if that matters.
> >
> > Is there something I am missing? The NIC is Intel Corporation Ethernet
> > Controller X710 for 10GbE SFP+ (rev 01).
> >
> > What is more, is there any particular reason for assuming in
> > i40e_xmit_pkts that offloading checksums is unlikely (I mean the line 
no
> > 1307 "if (unlikely(ol_flags & I40E_TX_CKSUM_OFFLOAD_MASK))" at
> > dpdk-2.0.0/lib/librte_pmd_i40e/i40e_rxtx.c)?
> >
> > Regards,
> > Angela
> 
> 
> 
> -- 
> Andriy Berestovskyy
>