Re: [liblo] IPv6

Hi Stephen,


On 21 nov. 2011, at 20:09, Stephen Sinclair wrote:

> After a month of working on an unrelated project I finally have time
> to get back to this :)
> Sorry for the delay.

Thank you!
I appreciate you spend time on this.


> I've just been testing this IPV6 patch on Linux (Ubuntu 10.10) and
> iMac (10.6.8), and can report the following.  With PF_UNSPEC  and
> V6ONLY enabled on the server, if the client specifies the hostname as:
> 
> Ubuntu10.10      msg received     lo_send returned
> "localhost"      yes                     number of bytes
> "::1"                 yes                     number of bytes
> "127.0.0.1"      no                       number of bytes
> "::FFFF:127.0.0.1"  no               number of bytes
> 
> OSX 10.6.8
> "localhost"      no                       number of bytes
> "::1"                 yes                     number of bytes
> "127.0.0.1"      no                       number of bytes
> "::FFFF:127.0.0.1"  no               number of bytes
> 
> With IPV6ONLY disabled,
> 
> Ubuntu 10.10:
> "localhost"      yes                     number of bytes
> "::1"                 yes                     number of bytes
> "127.0.0.1"      yes                     number of bytes
> "::FFFF:127.0.0.1"  yes             number of bytes
> 
> OSX 10.6.8:
> "localhost"      yes                     number of bytes
> "::1"                 yes                     number of bytes
> "127.0.0.1"      yes                     number of bytes
> "::FFFF:127.0.0.1"  yes             number of bytes
> 
> So, I never observed lo_send() returning error 22, contrary to your
> results, which is strange.  It could simply be a difference between
> the order of the NICs in the two machines, the wifi vs. wired
> configuration, etc.  (I was testing on a wired ethernet connection.)

Right, I was testing using the wifi adapter.


> The only difference with Ubuntu seems to be that the result of looking
> up "localhost" results in IPv4 on Mac OS X but in IPv6 on Linux.

I prefer the results of Ubuntu.  But if you have a look at /etc/hosts on Mac OS X it does indeed have the IPv6 addresses for localhost.  Oh well ...


> However, it's clear that V6ONLY is working on both operating systems,
> and using PF_UNSPEC is correct when "::FFFF" is prepended.  Moreover I
> never observed a case where the loop over addrinfo actually ran more
> than once.  But I see no problem in iterating and saving the results,
> if that potentially solves a problem.  It's easy to simply save the
> result in lo_address if the loop discovers a successful addrinfo later
> in the list, so it should only execute the loop once.

Sounds good to me!


> I think I can safely commit this patch (done) but some independent
> testing would be appreciated.

Thank you Steve.
I'll be back in a short while with some questions about liblo and TCP.

I think having IPv6 and TCP support in liblo is a real plus.


Best,
Cam