svn commit: r257696 - in head: libexec/rbootd share/man/man9 sys/compat/svr4 sys/net sys/sys

[John Baldwin]

On Tuesday, November 05, 2013 3:42:17 pm Gleb Smirnoff wrote:
>   John,
> 
> On Tue, Nov 05, 2013 at 02:47:52PM -0500, John Baldwin wrote:
> J> On Tuesday, November 05, 2013 2:29:04 pm Gleb Smirnoff wrote:
> J> > On Tue, Nov 05, 2013 at 11:56:09AM -0500, John Baldwin wrote:
> J> > J> On Tuesday, November 05, 2013 5:29:48 am Gleb Smirnoff wrote:
> J> > J> > Author: glebius
> J> > J> > Date: Tue Nov  5 10:29:47 2013
> J> > J> > New Revision: 257696
> J> > J> > URL: http://svnweb.freebsd.org/changeset/base/257696
> J> > J> > 
> J> > J> > Log:
> J> > J> >   Drop support for historic ioctls and also undefine them, so that code
> J> > J> >   that checks their presence via ifdef, won't use them.
> J> > J> 
> J> > J> Most of these are COMPAT_43, but one appears to be a 9.x ioctl?  If that's the
> J> > J> case it's implementation should probably stick around under appropriate
> J> > J> COMPAT_FREEBSD<x> macros.  It looks like it goes all the way back to 4.4BSD,
> J> > J> so at least COMPAT_FREEBSD4 and later should define the implementation to
> J> > J> preserve ABI compat for old binaries.
> J> > 
> J> > Why should we support such broken configurations as running new kernel and
> J> > ancient core base system utilities? The efforts to keep this are much more
> J> > expensive, then yields.
> J> 
> J> Is this ioctl only ever used by ifconfig and not suitable for public consumption?
> J> If so, then I think removing it is fine.  However, it's not clear that this is
> J> the case from the commit, and it's good to make sure it is really the case.
> J> 
> J> It might be nice to hide ioctls we think are internal under some #ifdef that tools
> J> like ifconfig #define to expose them so we are more explicit about which ioctls
> J> are purely internal, etc.
> 
> Well, it isn't hidden and actually some applications as zebra/quagga can use it.
> 
> On previous hacking session at this area, 2 years ago, I noticed that zebra/quagga
> do use SIOCAIFADDR and it actually does better at filling sockaddrs than our
> ifconfig :)
> 
> I am pretty sure that no closed source, but available to wide public, application
> that configures addresses in FreeBSD kernel exist.
> 
> In case of open source applications, like zebra/quagga, supporting one major
> release behind should be enough.

Mmmm, people run older versions of binaries (even open source ones) on newer OS's
perhaps more often than you think.   The COMPAT_43 stuff can be dropped certainly,
but people will almost certainly do rolling upgrades where they upgrade the OS
on their machines before they upgrade their packages.

-- 
John Baldwin