bug in route tables handling triggered by ppp

[David Rhodus]

On 3/13/06, Matthew Dillon <dillon at xxxxxxxxxxxxxxxxxxxx> wrote:
>
> :...
> :#/etc/rc.d/ppp-user start
> :Starting ppp as "root"
> :Warning: Add! route failed: ff02:: errno: Operation not supported
> :Warning: tun0: AIFADDR 213.41.166.51 -> 10.0.0.2 returns 0
> :#panic: rtrequest1_msghandler: rtrequest table error was not on CPU #0:
> :Note: panic took place two seconds after the shell prompted again.
> :db> trace
> :Debugger(c02cc075) at Debugger+0x3d
> :panic(c02d2b07,c9390c5c,0,c5c9fa00,ff808000) at panic+0x162
> :rtrequest1_msghandler(c9390c5c) at rtrequest1_msghandler+0x83
> :rtable_service_loop(0,0,0,0,0) at rtable_service_loop+0x13
> :lwkt_exit() at lkwt_exit
> :
> :At complete random, i had a look at ppp(8) and found my set ifaddr line
> :quite wrong:
> :set ifaddr 213.41.166.51 10.0.0.2 255.255.255.0 0.0.0.0
> :After fixing that to:
> :set ifaddr 213.41.166.51 62.4.16.246 255.255.255.255 213.41.166.51
> :i no longer see panics, even in the 100% reproductible case (single-user
> :mode), and my route tables are ok. ppp properly adds default routes (i
> :have a native ipv6 link, thanks Nerim!), though it still warns about the
> :"ff02::" route entry, which i'll investigate later on.
> :
> :If anyone really want it thoroughly debugged, i can provide informations
> :with kgdb instead of a dump, just let me know.
> :
> :Francis.
>
>     This is going to be hard to find without a dump.  I know there are
>     definitely issues related to the default route and also issues with IPV6.
>
>     That particular panic occurs if a route table request succeeds on cpu #0
>     but then fails on cpu #1's route table, indicating a synchronization
>     issue between the replicated route tables.
>
>                                         -Matt


On my machine I can trigger a panic just like this by doing `sh
/etc/rc` on a machine that is already booted and has ifconfig
information in /etc/rc.conf.

-DR