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

[Sergey Kandaurov]

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.

-- 
wbr,
pluknet