kern/48945: CARP preempt is not working

[netbsd%seirios.org@localhost]

>Number:         48945
>Category:       kern
>Synopsis:       CARP preempt is not working
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Jun 24 09:05:00 +0000 2014
>Originator:     HEO SeonMeyong
>Release:        NetBSD 6.1 stable
>Organization:
>Environment:
NetBSD slb001 6.1_STABLE NetBSD 6.1_STABLE (XEN3_DOMU) #0: Tue Jun 24 15:16:34 
JST 2014  
seirios@dev001:/export/NetBSD/src-rel/sys/arch/amd64/compile/XEN3_DOMU amd64
>Description:
- CARP preempt is not working.

1. Environment
There are two NetBSD router (on XenServer)
- Kernel is XEN3_DOMU + with followings.
        pseudo-device   carp                    # Common Address Redundancy 
Protocol
        options         BRIDGE_IPF              # bridge uses IP/IPv6 pfil 
hooks too
        pseudo-device   pf                      # PF packet filter
        pseudo-device   pflog                   # PF log if
The Router has two Interfaces connect to Net-A and Net-B
Router-A(rt-A)'s xennet0 and Router-B(rt-B)'s xennet0 is connect to Net-A
Router-A(rt-A)'s xennet1 and Router-B(rt-B)'s xennet1 is connect to Net-B

2. Configuration
Both Router is configured followings.
        sysctl net.inet.ip.forwarding=1
        sysctl net.inet.carp.allow=1
        sysctl net.inet.carp.preempt=1
        sysctl net.inet.carp.log=1

rt-A
        ifconfig xennet0 inet 192.0.2.2/24
        ifconfig carp0 vhid 200 advbase 1 advskew 100 pass testTEST 192.0.2.1/24
        ifconfig xennet1 inet 198.51.100.2/24
        ifconfig carp1 vhid 201 advbase 1 advskew 100 pass TESTtest 
198.51.100.1/24

rt-B
        ifconfig xennet0 inet 192.0.2.3/24
        ifconfig carp0 vhid 200 advbase 1 advskew 100 pass testTEST 192.0.2.1/24
        ifconfig xennet1 inet 198.51.100.3/24
        ifconfig carp1 vhid 201 advbase 1 advskew 100 pass TESTtest 
198.51.100.1/24

3. How NOT works
  - Initial rt-A's carp0 and carp1 is MASTER / rt-B's carp0 and carp1 is BACKUP
  - run "ifconfig carp0 down" on rt-A
  - rt-A's carp0's state change to INIT but carp1's state is still MASTER
  - rt-B's carp0's state change to MASTER but carp1's state is still MASTER

I think this behavior is bug. rt-A's carp1's state is change to BACKUP when 
CARP preempt=1
>How-To-Repeat:
See Full description.
>Fix: