kern/185023: Closing tun<n> interface deconfigures IP address

[John P Hartmann]

>Number:         185023
>Category:       kern
>Synopsis:       Closing tun<n> interface deconfigures IP address
>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:   Fri Dec 20 11:20:01 UTC 2013
>Closed-Date:
>Last-Modified:
>Originator:     John P Hartmann
>Release:        9.1
>Organization:
Self
>Environment:
[root at fb91 ~]# uname -a
FreeBSD fb91.jphartmann.net 9.1-RELEASE-p7 FreeBSD 9.1-RELEASE-p7 #0: Mon Sep  9 21:34:37 UTC 2013     root at amd64-builder.daemonology.net:/usr/obj/usr/src/sys/GENERIC  amd64

>Description:
When a /dev/tun special file is closed, it loses its assigned IP address.  

Looks like it happens near line 467 of if_tun.c (the close routine), but I am not sure exactly where.

>How-To-Repeat:
[root at fb91 ~]# ifconfig tun0 up 10.0.0.103  10.0.0.104
[root at fb91 ~]# ifconfig tun0
tun0: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> metric 0 mtu 1500
        options=80000<LINKSTATE>
        inet6 fe80::7254:d2ff:fe45:e0a0%tun0 prefixlen 64 scopeid 0x5 
        inet 10.0.0.103 --> 10.0.0.104 netmask 0xff000000 
        nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>
[root at fb91 ~]# cat /dev/tun0
^C
[root at fb91 ~]# ifconfig tun0
tun0: flags=8010<POINTOPOINT,MULTICAST> metric 0 mtu 1500
        options=80000<LINKSTATE>
        nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>

>Fix:


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