UDP Lite support

[Kevin Lo]

On 2014/03/26 23:22, John Baldwin wrote:
> On Friday, March 21, 2014 3:38:19 am Kevin Lo wrote:
>> On 2014/03/03 04:08, Xin Li wrote:
>>> -----BEGIN PGP SIGNED MESSAGE-----
>>> Hash: SHA512
>>>
>>> On 3/2/14, 10:42 AM, Joe Nosay wrote:
>>>> On Thu, Feb 27, 2014 at 3:22 AM, Joe Nosay <superbisquit at gmail.com>
>>>> wrote:
>>>>
>>>>>
>>>>> On Wed, Feb 26, 2014 at 11:19 PM, Xin Li <delphij at delphij.net>
>>>>> wrote:
>>>>>
>>>> On 02/26/14 18:52, Joe Nosay wrote:
>>>>>>>> On Wed, Feb 26, 2014 at 9:19 PM, Brooks Davis
>>>>>>>> <brooks at freebsd.org> wrote:
>>>>>>>>
>>>>>>>>> On Wed, Feb 26, 2014 at 07:36:29PM -0500, Joe Nosay
>>>>>>>>> wrote:
>>>>>>>>>> The last thread on this was in 2006. Has it ever been
>>>>>>>>>> reconsidered or is the likelihood of too many damaged
>>>>>>>>>> packets the reason for not supporting? I'm not sure
>>>>>>>>>> where to put this question. Apologies for the noise.
>>>>>>>>> You've provided next to no context.  What is the
>>>>>>>>> question?  What thread are you referring to?  If this is
>>>>>>>>> the usual UDP then freebsd-net would be vastly more
>>>>>>>>> appropriate than -current.
>>>>>>>>>
>>>>>>>>> -- Brooks
>>>>>>>>>
>>>>>>>> Thanks. I will ask kevlo and maybe bring it up on
>>>>>>>> freebsd-net. It has to do with an implementation of the
>>>>>>>> JACK server using UDP Lite for transferring data.
>>>>>>>>
>>>>>>>>
>>>> http://freebsd.1045724.n5.nabble.com/UDP-lite-for-FreeBSD-td4010236.html
>>>>
>>>>    Looks
>>>> like nobody proposed a patch?
>>>>
>>>> I think the concern was that this is not very useful in real-world
>>>> scenarios due to link layer error detection mechanism but that
>>>> doesn't raise a red flag to me assuming this is sufficiently self
>>>> contained feature as it would improve compatibility with other
>>>> operating systems.
>>>>
>>>> Cheers,
>>>>> https://github.com/torelizer/jack_trauma
>>>>>
>>>>> Not my project;  but, I want to port it to FreeBSD. First is to
>>>>> get it to build from source. Use  your raspberry pi with FreeBSD
>>>>> to broadcast your tunes and all.
>>>>>
>>>> Thanks for all of the input. The project is being reworked to
>>>> improve the code.
>>> Kevin Lo have a patchset but needs someone to do performance testing
>>> (its impact on non-UDPLite applications), test with vimage, etc:
>>>
>>> 	http://people.freebsd.org/~kevlo/udplite.diff
>>> 	http://people.freebsd.org/~kevlo/udp-v.diff
>>>
>>> Are you interested in working on these and report back?
>> The revised patch is available at:
>> http://people.freebsd.org/~kevlo/udplite.diff

Thank you for your suggestions.

> A few suggestions:
>
> - I would just drop the INP lock and return EOPNOTSUPP directly rather
>    than using goto's to 'bad_setoptname' and 'bad_getoptname' so the
>    UDP-lite options are self-contained.

Fixed.

> - I'm not a super big fan of all the udp_common_* macros only because
>    I think it obfuscates things.  At the very least, please move these
>    things out of the header and into udp_usrreq.c so they are closer
>    to the implementation.  I would even suggest making them inline
>    functions instead of macros.

Okay, I removed two udp_common_* macros.  I also renamed udp_common_init()
to udp_udplite_init() and moved it into udp_usrreq.c.  Using a macro here
to follow the style used in SCTP (sctp_os_bsd.h).

Here's a third version of the udp-lite patch:
http://people.freebsd.org/~kevlo/udplite.diff

>
> However, I think the patch generally looks ok.

Cool!  Thanks again for your review of udp-lite's patch :-)

     Kevin