Introduce a number of changes to the MROUTING code.

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

1 files changed, 7 insertions, 0 deletions

diff --git a/UPDATING b/UPDATING
index 6b490fc..3864a0d 100644
--- a/UPDATING
+++ b/UPDATING
@@ -22,6 +22,13 @@ NOTE TO PEOPLE WHO THINK THAT FreeBSD 8.x IS SLOW:
 	to maximize performance.  (To disable malloc debugging, run
 	ln -s aj /etc/malloc.conf.)
 
+20090319:
+	The multicast forwarding code has been cleaned up. netstat(1)
+	only relies on KVM now for printing bandwidth upcall meters.
+	The IPv4 and IPv6 modules are split into ip_mroute_mod and
+	ip6_mroute_mod respectively. The config(5) options for statically
+	compiling this code remain the same, i.e. 'options MROUTING'.
+
 20090315:
 	Support for the IFF_NEEDSGIANT network interface flag has been
 	removed, which means that non-MPSAFE network device drivers are no