Re: [PATCH net-next] af_mpls: fix undefined reference to ip6_route_output

[Thomas Graf <tgraf@suug.ch>]

On 07/22/15 at 01:04pm, David Miller wrote:
> From: Thomas Graf <tgraf@suug.ch>
> Date: Wed, 22 Jul 2015 21:57:06 +0200
> 
> > On 07/22/15 at 12:30pm, roopa wrote:
> >> diff --git a/net/mpls/Kconfig b/net/mpls/Kconfig
> >> index 5c467ef..2b28615 100644
> >> --- a/net/mpls/Kconfig
> >> +++ b/net/mpls/Kconfig
> >> @@ -24,6 +24,8 @@ config NET_MPLS_GSO
> >> 
> >>  config MPLS_ROUTING
> >>         tristate "MPLS: routing support"
> >> +       depends on INET
> >> +       depends on IPV6
> >>         ---help---
> >>          Add support for forwarding of mpls packets.
> > 
> > This looks like a much better fix to me and resolves the
> > module/built-in dependency mess.
> 
> It's only OK if we don't create a new hard dependency on IPV6,
> which this patch does.
> 
> Consitently across the tree we give the user the option of
> using a bi-AF facility with or without IPV6.

OK. I guess there is an MPLS routing use case which does not
depend on INET or IPV6 if all routes specify an RTA_OIF. Not
enough of an expert to know if that is the common case or not.

Otherwise I would have argued to start dropping the special status
for IPv6 and start treating IP dependency as a combination of both
to promote it further/faster. It can still be explicitly disabled.
Then again, I might be too optimistic in assuming that this will
be the year of IPv6 ;-)