Re: refactoring ip_output() and the L2 _output()

[Ryota Ozaki <ozaki-r%netbsd.org@localhost>]

Thanks to kefren@ we have more MPLS tests. I confirmed my patch
passes the tests.

Thanks,
  ozaki-r

On Wed, May 27, 2015 at 1:10 PM, Ryota Ozaki <ozaki-r%netbsd.org@localhost> wrote:
> On Tue, May 26, 2015 at 11:00 PM, Ryota Ozaki <ozaki-r%netbsd.org@localhost> wrote:
>> On Tue, May 26, 2015 at 7:55 PM, Mihai Chelaru <chelaru%gmail.com@localhost> wrote:
>>> On 26/05/15 05:42, Ryota Ozaki wrote:
>>>>
>>>> Hi,
>>>>
>>>> The mail subject may recall someone an old thread:
>>>> https://mail-index.netbsd.org/tech-net/2013/02/01/msg003847.html
>>>>
>>>> Yes, I'm taking over the task :)
>>>>
>>>>
>>>> http://www.netbsd.org/~ozaki-r/refactor_l2_output.diff
>>>>
>>>> The patch is basically the same as dyoung's patch with some
>>>> tweaks to make it work on -current; it gets rid of route
>>>> lookups from L2 output routines such as ether_output
>>>> and puts them between ip_output and L2 output routines.
>>>>
>>>> One known issue of the change is that it adds an mbuf flag
>>>> to tell ether_output that mbuf is to be set MPLS ether
>>>> type. I don't think it's the best way but I don't have
>>>> another better approach for now.
>>>>
>>>> Any comments or suggestions are welcome.
>>>>
>>>> Thanks,
>>>>    ozaki-r
>>>>
>>>
>>> Hi there,
>>>
>>> I have some questions/observations:
>>>
>>> * This cod is generic enough to be linked apart from ip_output.c Maybe it
>>> can be reused by other protocols as well ? (hint nd6_output)
>>
>> I think so, but not tried yet. I'll try tomorrow.
>>
>>> * did this patch passed the current net tests ?
>>
>> Yes!
>>
>>>
>>> Now about MPLS:
>>>
>>> * I'm kinda reluctant in using flags to describe protocol specifics, maybe
>>> should use a tag for now instead of flags even if this interface is slower ?
>>
>> Sure. So we can postpone to add something. We would have a better solution then.
>
> http://www.netbsd.org/~ozaki-r/use-mtag.diff
>
> Hm, we still need to add a mtag type (it's still better than adding
> a flag though). We have an option to reuse PACKET_TAG_NONE, but
> it's not good, I think :-/
>
>   ozaki-r
>
>>
>>> * I think flagging/tagging should also be used in mpls LSE - probably in
>>> send_frame.
>>
>> I'm not sure. Without flagging/tagging for LSE, all tests of MPLS pass.
>>
>>> * and also in ip6 output path. I'll try to find time this week to write some
>>> tests for ip6/mpls - but you can test using route.
>>> * mpls/gre needs also to be hacked because it uses the same test (have to
>>> write a test for mpls+gre, too)
>>
>> Such tests are welcome! We need much more tests for networking.
>>
>> Thanks,
>>   ozaki-r