kern/168245: [regression] Permanent ARP entry not deleted on interface configuration failure

[Arnaud Lacombe]

>Number:         168245
>Category:       kern
>Synopsis:       [regression] Permanent ARP entry not deleted on interface configuration failure
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Wed May 23 02:10:15 UTC 2012
>Closed-Date:
>Last-Modified:
>Originator:     Arnaud Lacombe
>Release:        9.0-RELEASE
>Organization:
n/a
>Environment:
>Description:
Permanent ARP entry not deleted on interface configuration failure. Older FreeBSD (ie. 7.1) does not show this bug.
>How-To-Repeat:
# ifconfig vr0 172.31.0.1
# route delete 172.31.0.1
delete host 172.31.0.1
# route delete 172.31.0.0/16
delete net 172.31.0.0
# route add 172.31.0.1 -iface vr1
add host 172.31.0.1: gateway vr1
# ifconfig vr0 delete 172.31.0.1

At this point, only the route to 172.31.0.1 exist, ARP for 172.31.0.1 has been cleared.

# ifconfig vr0 172.31.0.1
ifconfig: ioctl (SIOCAIFADDR): File exists

The stale route entry cause the configuration to fail, leading to:

# ifconfig vr0
vr0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
        options=8280b<RXCSUM,TXCSUM,VLAN_MTU,WOL_UCAST,WOL_MAGIC,LINKSTATE>
        ether 00:00:24:cb:f4:90
        nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
        media: Ethernet autoselect (100baseTX <full-duplex>)
        status: active

this is expected, however:

# arp -a
[...]
? (172.31.0.1) at 00:00:24:cb:f4:90 on vr0 permanent [ethernet]

This should have been cleared while returning from the configuration path.
>Fix:


>Release-Note:
>Audit-Trail:
>Unformatted: