Routing enhancement - reduce routing table locking

[Ingo Flaschberger]

>> Can you say something more about :
>>    "implement some multipath changes to use a direct attached
>>      interface route and a real route, used some OpenBSD code"
>> 
>> I've looked at the patch but it's not obvious to me.
>> 
>> P.S.: I've just saw your reply to kern/155772 and was wondering if this 
>> patch can help.
>
> regarding kern/155772:
> at stock 8.2 FreeBSD the system panics after ifconfig down / ifconfig up / 
> ifconfig down with 1 route and 1 interface route (multipath).
>
> Also there are problems with arp, due wrong multipath route selection
> (if the decision is already made that the route should go the direct way, the 
> route and not the interface route is choosen, depends on which route was 
> first in the tree).

see "in_lltable_rtcheck"

> And finally, there are problems when adding / deleteing routes.
>
> example that does not work:
> ifconfig em0 192.168.0.1/24
> ifconfig em1 10.0.0.1/24
> route add 10.0.0.0/24 192.168.0.2
>
> example that currently works with 8.2:
> ifconfig em0 192.168.0.1/24
> ifconfig em1 10.0.0.1/24
> route add 172.16.0.0/24 192.168.0.2
> route add 172.16.0.0/24 10.0.0.2
>
> Kind regards,
> 	Ingo Flaschberger