On Tue, Sep 22, 2020 at 10:03:29PM +0200, Klemens Nanni wrote:
> We have never been able to remove an rtable; until claudio moved them
> explicitly with rtable_l2set() in if_loop.c:loop_clone_destroy(), i.e.
>
> revision 1.90
> date: 2020/01/08 09:09:10; author: claudio; state: Exp; lines: +6 -2;
> In loop_clone_destroy() reset the rdomain with rtable_l2set() after
> the if_detach() call. In if_detach() various route messages are
> generated
> and during that time the rtable_l2() mapping needs to stay.
> OK kn@
>
> it would still exist but not be assigned to any valid rdomain. Back then this
> could be obvserved with `route -T1 ...' still "working" after having
> destroyed lo1.
>
> Reverting claudio's commit on -CURRENT, that is with `netstat -R' now
> available, confirms this:
>
> # sysctl kern.version
> kern.version=OpenBSD 6.8-beta (GENERIC) #0: Tue Sep 22 21:24:48 CEST
> 2020
> kn@eru:/sys/arch/amd64/compile/GENERIC
> # ifconfig lo1 rdomain 1
> # netstat -R
> Rdomain 0
> Interfaces: lo0 vio0
> Routing table: 0
>
> Rdomain 1
> Interface: lo1
> Routing table: 1
>
> # ifconfig lo1 destroy
> # netstat -R
> Rdomain 0
> Interfaces: lo0 vio0
> Routing table: 0
>
> # route -T1 show
> Routing tables
> # echo $?
> 0
>
>
> This is not documented anywhere and I'd certainly not expect it after
> reading rtable(4). The manual says we can delete rdomains and is quiet
> about deleting rtables, which can imply that rtables cannot be deleted
> but might also imply that rtables are deleted automatically when
> rdomains are deleted.
>
> Either way, explicit is better here, I think.
>
> Feedback? OK?
The comment at the beginning of src/sys/net/rtable.c is the only
place I'm aware of that documents that routing tables can not be
deleted.
I think it makes sense to document this in rtable(4).
ok remi@
>
>
> Index: rdomain.4
> ===
> RCS file: /cvs/src/share/man/man4/rdomain.4,v
> retrieving revision 1.14
> diff -u -p -r1.14 rdomain.4
> --- rdomain.4 30 Jul 2020 21:44:34 - 1.14
> +++ rdomain.4 22 Sep 2020 19:58:57 -
> @@ -146,3 +146,5 @@ and IPv6 support first appeared in
> .Sh CAVEATS
> No tool is available to assign more than one rtable to an rdomain
> other than to the default one (0).
> +An rtable cannot be deleted.
> +Deleting an rdomain will move its rtable into the default rdomain.
>
