[RFC] Prune net.inet6.ip6.rr_prune?

[Garrett Cooper]

On Wed, Nov 21, 2012 at 3:07 PM, Sergey Kandaurov <pluknet at gmail.com> wrote:
> On 21 November 2012 22:39, Garrett Cooper <yanegomi at gmail.com> wrote:
>>     While going through the tree trying to document all of our
>> net.inet6 sysctls, I noticed that net.inet6.ip6.rr_prune is defined,
>> but not actually used anywhere in the stack:
>>
>> netinet6/ip6_var.h:VNET_DECLARE(int, ip6_rr_prune);  /* router
>> renumbering prefix
>> netinet6/ip6_var.h:#define   V_ip6_rr_prune                  VNET(ip6_rr_prune)
>> netinet6/in6_proto.c:VNET_DEFINE(int, ip6_rr_prune) = 5;     /* router
>> renumbering prefix
>> netinet6/in6_proto.c:SYSCTL_VNET_INT(_net_inet6_ip6, IPV6CTL_RR_PRUNE,
>> rr_prune, CTLFLAG_RW,
>> netinet6/in6_proto.c:        &VNET_NAME(ip6_rr_prune), 0,
>>
>>     The knob was declared in r181803 and shuffled around a few times,
>> but isn't in use anywhere (either then or now).
>>     Should I send out a PR to remove it (or am I missing some context)?
>
> I believe this knob became unused with invalidation of the prefix
> manipulation mechanism (including prefix or router renumbering, rfc2894)
> at KAME about 11 years ago. It was intended to schedule in6_rr_timer()
> callout every ip6_rr_prune seconds to check for expired prefixes and
> delete the associated addresses from interface.
> Last bits of old ipv6 prefix management stuff cleaned up in r231229.

    Interesting. If I don't get any negative feedback, I'll roll it
into the patch I was going to submit better documenting the sysctls
that I was going to submit via a PR.
Thanks!
-Garrett