Mike Belopuhov(m...@belopuhov.com) on 2017.01.13 13:28:01 +0100:
> On Fri, Jan 13, 2017 at 13:15 +0100, Mike Belopuhov wrote:
> > On 13 January 2017 at 13:11, Sebastian Benoit <be...@openbsd.org> wrote:
> > > On current, there seem to be two problems with lo(4) interfaces:
> > >
> > > 1. "ifconfig lo6 up" fails
> > >
> > > # ifconfig lo6 create
> > > # ifconfig lo6 up
> > > ifconfig: SIOCSIFFLAGS: Inappropriate ioctl for device
> > > # ifconfig lo6 destroy
> > > #
> > >
> > > The sys/net/rdomains regress test fails because of this, and i think
> > > sys/net/if.c rev 1.473 might be the cause.
> > >
> > > It still works on a kernel from early December.
> > >
> > > 2. "ifconfig lo6 destroy" fails on an interface in an rdomain
> > >
> > > # ifconfig lo6 create
> > > # ifconfig lo6 rdomain 6
> > > # ifconfig lo6
> > > lo6: flags=8008<LOOPBACK,MULTICAST> rdomain 6 mtu 32768
> > > index 12 priority 0 llprio 3
> > > groups: lo
> > > # ifconfig lo6 destroy
> > > ifconfig: SIOCIFDESTROY: Operation not permitted
> > >
> > > This has been broken a bit longer, it still works in 6.0.
> > >
> >
> > it's not broken, we have introduced automagic loopback interface
> > creation when you create an rdomain. this means you have to do
> > "ifconfig lo6 create rdomain 6".
>
> However, I've just found a subtle bug here: destroying a loopback
> interface corresponding to a newly created rdomain will fail, while
> destroying loopback interfaces created in the same rdomain afterwards
> will work. Observe:
>
> kemushi:~% sudo ifconfig lo9 create rdomain 9
> kemushi:~% sudo ifconfig lo9
> lo9: flags=8008<LOOPBACK,MULTICAST> rdomain 9 mtu 32768
> index 13 priority 0 llprio 3
> groups: lo
> kemushi:~% sudo ifconfig lo9 destroy
> ifconfig: SIOCIFDESTROY: Operation not permitted
> kemushi:~% sudo ifconfig lo9 rdomain 0
> kemushi:~% sudo ifconfig lo9 destroy
>
> Now we create lo9 again in the same rdomain:
>
> kemushi:~% sudo ifconfig lo9
> lo9: no such interface
> kemushi:~% sudo ifconfig lo9 create rdomain 9
> kemushi:~% sudo ifconfig lo9
> lo9: flags=8008<LOOPBACK,MULTICAST> rdomain 9 mtu 32768
> index 14 priority 0 llprio 3
> groups: lo
> kemushi:~% sudo ifconfig lo9 destroy
> kemushi:~%
Here is another "thing":
# ifconfig lo15 rdomain 15 up
# ifconfig lo15
lo15: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> rdomain 15 mtu 32768
index 18 priority 0 llprio 3
groups: lo
inet6 ::1 prefixlen 128
inet6 fe80::1%lo15 prefixlen 64 scopeid 0x12
-> the interface gets the ::1 address
# ifconfig lo15 rdomain 0
# ifconfig lo15 destroy
# ifconfig lo15 rdomain 15 up
# ifconfig lo15
lo15: flags=8009<UP,LOOPBACK,MULTICAST> rdomain 15 mtu 32768
index 19 priority 0 llprio 3
groups: lo
-> the interface does not get the ::1 address
The difference is, that in the second case, the (empty) rtable 15 still
exists, as it is not deleted when the interface is moved to rdomain 0.
# ifconfig lo15 destroy
# route -T 15 show
Routing tables
#
