This is purely a forwarding plane cleanup; no control plane
code is involved.
Summary:
* Split IPv4 and IPv6 MROUTING support. The static compile-time
kernel option remains the same, however, the modules may now
be built for IPv4 and IPv6 separately as ip_mroute_mod and
ip6_mroute_mod.
* Clean up the IPv4 multicast forwarding code to use BSD queue
and hash table constructs. Don't build our own timer abstractions
when ratecheck() and timevalclear() etc will do.
* Expose the multicast forwarding cache (MFC) and virtual interface
table (VIF) as sysctls, to reduce netstat's dependence on libkvm
for this information for running kernels.
* bandwidth meters however still require libkvm.
* Make the MFC hash table size a boot/load-time tunable ULONG,
net.inet.ip.mfchashsize (defaults to 256).
* Remove unused members from struct vif and struct mfc.
* Kill RSVP support, as no current RSVP implementation uses it.
These stubs could be moved to raw_ip.c.
* Don't share locks or initialization between IPv4 and IPv6.
* Don't use a static struct route_in6 in ip6_mroute.c.
The v6 code is still using a cached struct route_in6, this is
moved to mif6 for the time being.
* More cleanup remains to be merged from ip_mroute.c to ip6_mroute.c.
v4 path tested using ports/net/mcast-tools.
v6 changes are mostly mechanical locking and *have not* been tested.
As these changes partially break some kernel ABIs, they will not
be MFCed. There is a lot more work to be done here.
Reviewed by: Pavlin Radoslavov
