[dpdk-dev] ip_chksum not updated in ipsec-secgw application

Sergio Gonzalez Monroy sergio.gonzalez.monroy at intel.com
Mon Jul 18 16:00:34 CEST 2016


On 18/07/2016 14:49, Akhil Goyal wrote:
> On 7/18/2016 6:27 PM, Sergio Gonzalez Monroy wrote:
>> Hi,
>>
>> On 18/07/2016 13:41, Akhil Goyal wrote:
>>> Hi,
>>>
>>> In Ipsec-secgw application, while adding the outer IP header, it seems
>>> that the application does not update the checksum value for outbound
>>> packets. This result in incorrect ip->checksum in the encrypted packet.
>>>
>>> Please let me know if the checksum value is updated somewhere else or
>>> not.
>>>
>>> Also In case of inner ip header also the TTL value is decremented by
>>> one but the checksum value is not updated. Is it intentional or it is
>>> done somewhere else?
>>
>> It is intentional. The application is using IP checksum offload but just
>> looking now at the code there is a bug for IPv6 packets where the flag
>> does not get setup.
>> Is it only for IPv6 traffic that you are having this issue?
>>

Duh! moment here.
No checksum for IPv6, that's why the flag is not setup so the code is 
correct
as it is, it just needs IPv4 checksum offload support.

Sergio

>> For IPv4 traffic the PKT_TX_IP_CKSUM flag is setup in 'prepare_tx_pkt'
>> function in ipsec-secgw.c
>>
>> Sergio
>>
>
> Thanks Sergio, got your point. I missed the flag. I was using it for 
> IPv4.
>
> Akhil
>
>



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