[libvirt] [PATCH v3 3/5] conf: Add 'family' attribute to <graphics> 'listen' element

Ján Tomko jtomko at redhat.com
Wed Mar 11 07:39:01 UTC 2015


On Tue, Mar 10, 2015 at 07:43:16PM -0400, John Ferlan wrote:
> 
> 
> On 03/10/2015 12:58 PM, Ján Tomko wrote:
> > On Mon, Mar 09, 2015 at 08:04:59PM -0400, John Ferlan wrote:
> >> From: Luyao Huang <lhuang at redhat.com>
> >>
> >> If an interface or network has both ipv6 and ipv4 addresses which can
> >> be used, we do not know which to use as a listen address. This patch
> >> introduces the 'family' attribute to allow the XML to determine whether
> >> the desire is to use IPv6 instead of IPv4 as the listen family to use.
> >> The default will remain IPv4.
> >>
> > 
> > As Laine mentioned in his reply to v1:
> > https://www.redhat.com/archives/libvir-list/2015-February/msg01080.html
> > This is intended to be run only on networks with one address. With more
> > addresses, you cannot control which one to use.
> 
> It's been a while since I've had to "think" whether getifaddrs() would
> return the same IPv4 address in the "first" entry as would be return
> from the ioctl(SIOCGIFADDR)...  IIRC, IPv4 addresses can be aliased to
> the same device, but how getifaddrs handles returning addresses I just
> don't have recent exposure to..
> 
> > 
> > If you want to listen on IPv6, don't configure an IPv4 address on the
> > network and vice versa. This attribute does not seem that useful to me.
> > 
> > The original bug
> > https://bugzilla.redhat.com/show_bug.cgi?id=1192318
> > complained about 'no usable address'
> > 
> > I think the bug here is not treating an ipv6 address as an IP address,
> > not that we cannot choose the attribute by family.
> > 
> > Jan
> > 
> 
> hmmm... true we're really just looking to get "an" address and shouldn't
> care what style it is. However, what if someone has both configured and
> wants to force usage of one over the other?  Maybe they've separate
> their IPv4 and IPv6 addresses to connect to different places. Perhaps
> forcing certain protocols over IPv6 rather than IPv4? Since both can be
> defined in one <network> object - it's possible - how or why it would be
> done I haven't given too much thought to.
> 

They can configure another separate network, or create a hook that fills
in the proper <listen type='address'>.

If we allow filtering by family, should we also introduce filtering by a
netmask?

Jan
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 819 bytes
Desc: Digital signature
URL: <http://listman.redhat.com/archives/libvir-list/attachments/20150311/bab0ab60/attachment-0001.sig>


More information about the libvir-list mailing list