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

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

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.

> * 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