kern/45615: qemu's tap and bridge networking does not work on recent NetBSD kernel

[ryoon%NetBSD.org@localhost]

>Number:         45615
>Category:       kern
>Synopsis:       qemu's tap and bridge networking does not work on recent 
>NetBSD current
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Nov 14 19:05:00 +0000 2011
>Originator:     Ryo ONODERA
>Release:        NetBSD 5.99.56
>Organization:
        
>Environment:
        
        
System: NetBSD hydrogen.elements.tetera.org 5.99.56 NetBSD 5.99.56 (LEAFGIRL9) 
#13: Tue Nov 15 03:25:23 JST 2011 
root%hydrogen.elements.tetera.org@localhost:/usr/obj/sys/arch/i386/compile/LEAFGIRL9
 i386
Architecture: i386
Machine: i386
>Description:
On recent NetBSD/i386 5.99.56 kernel, qemu-system-*
from pkgsrc/emulators/qemu (qemu-0.15.1) with tap and bridge device
cannot connect to other hosts.
For example, ping to defaultroute fails.
http://cvsweb.netbsd.org/bsdweb.cgi/src/sys/net/if.c.diff?r1=1.253&r2=1.254&f=h
or other recent src/sys/net changes are rollbacked, qemu works fine.
        
>How-To-Repeat:
For example, on recent kernel, run
$ qemu-system-sparc -M SS-10 -m 128M -hda /home/ryo_on/emul/sparc/3GB.img 
-nographic -boot c -net nic -net tap,fd=3 3<>/dev/tap0
        
>Fix:
        


>Unformatted: