Re: UDP Lite support

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

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.
- 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.

However, I think the patch generally looks ok.

-- 
John Baldwin