[ovs-discuss] match/push/pop more than 3 MPLS labels

Stefano Salsano stefano.salsano at uniroma2.it
Wed Mar 11 12:01:16 UTC 2015


Il 27/02/2015 00:52, Pravin Shelar ha scritto:
> On Thu, Feb 26, 2015 at 5:17 AM, Stefano Salsano wrote:
>>
>> there is a limit of 3 MPLS labels that are supported by Open vSwitch
>> we need to raise it at 5 labels, to implement a segment routing scenario
>>
> You can start with changing FLOW_MAX_MPLS_LABELS to 5.

Dear Pravin,

thanks for your hint, we have tried and we realized that we also need to 
change an assert in lib/flow.h

current code is
BUILD_ASSERT_DECL(offsetof(struct flow, igmp_group_ip4) + 
sizeof(uint32_t) == sizeof(struct flow_tnl) + 192 && FLOW_WC_SEQ == 31);

we need to change it into:
BUILD_ASSERT_DECL(offsetof(struct flow, igmp_group_ip4) + 
sizeof(uint32_t) == sizeof(struct flow_tnl) + 176 + (4 * 
ROUND_UP(FLOW_MAX_MPLS_LABELS, 2)) && FLOW_WC_SEQ == 31);

basically, we need to split the 192 bytes in a fixed part of 176 bytes 
and in a part that depends on the number of supported MPLS labels

we tried it, and it compiles and runs well :-)

do you think it is OK ? do you want us to provide a patch ?

thank you

ciao
Stefano & Pier Luigi

>
>
>> any help or suggestion is welcome!
>>
>> I am trying on ovs-discuss list... may be the ovs-dev list is more
>> appropriate for this type of questions?
>>
>> thank you
>>
>> ciao
>> Stefano
>> --
>> *******************************************************************
>> Stefano Salsano
>> Professore Associato
>> Dipartimento Ingegneria Elettronica
>> Universita' di Roma Tor Vergata
>> Via del Politecnico, 1 - 00133 Roma - ITALY
>>
>> http://netgroup.uniroma2.it/Stefano_Salsano/
>>
>> E-mail  : stefano.salsano at uniroma2.it
>> Cell.   : +39 320 4307310
>> Office  : (Tel.) +39 06 72597770  (Fax.) +39 06 72597435
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>


-- 
*******************************************************************
Stefano Salsano
Professore Associato
Dipartimento Ingegneria Elettronica
Universita' di Roma Tor Vergata
Via del Politecnico, 1 - 00133 Roma - ITALY

http://netgroup.uniroma2.it/Stefano_Salsano/

E-mail  : stefano.salsano at uniroma2.it
Cell.   : +39 320 4307310
Office  : (Tel.) +39 06 72597770  (Fax.) +39 06 72597435
*******************************************************************



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