ng_pptpgre + netmask_change results to lock

[Nikos Vassiliadis]

On Tuesday 22 May 2007 10:06, I wrote:
> Hello everybody,
>
>  I just managed to lock my box and I want to report it
> in case it's known(or it helps in some way). It is a
> 6.2-STABLE from March 13. 

I did update to RELENG_6.

> The procedure that triggers 
> the lock is simple:
>
> 1) Create a pptp tunnel.
> 2) Set is as your default gateway.
> 3) Play a bit with the netmask of the physical inteface.
> In my case doing a few times:
> ifconfig fxp0 192.168.1.71/16
> ifconfig fxp0 192.168.1.71/24
> locks the box.

I also have to mention that the PPTP
server is not on 192.168.1.0/24.

My kernel cf contains:
options         KDB
options         DDB
options         INVARIANTS
options         INVARIANT_SUPPORT
options         WITNESS
options         WITNESS_KDB
options         DEBUG_LOCKS
options         DIAGNOSTIC
options         SOCKBUF_DEBUG
options         BREAK_TO_DEBUGGER

options         NETGRAPH
options         NETGRAPH_DEBUG
and several netgraph nodes.

I still cannot break to the debugger, is there anything
else I should add to my kernel cf?

root:0:~# ngctl list
There are 19 total nodes:
  Name: ngctl18236      Type: socket          ID: 0000003c   Num hooks: 0
  Name: <unnamed>       Type: pppoe           ID: 00000037   Num hooks: 2
  Name: <unnamed>       Type: socket          ID: 00000036   Num hooks: 1
  Name: mpd1899-sam-bpf Type: bpf             ID: 00000035   Num hooks: 5
  Name: mpd1899-sam-vjc Type: vjc             ID: 00000034   Num hooks: 4
  Name: mpd1899-sam     Type: ppp             ID: 00000033   Num hooks: 7
  Name: ng1             Type: iface           ID: 00000032   Num hooks: 2
  Name: mpd1899-sam-so  Type: socket          ID: 00000031   Num hooks: 2
  Name: <unnamed>       Type: socket          ID: 00000030   Num hooks: 0
  Name: <unnamed>       Type: ksocket         ID: 0000002f   Num hooks: 1
  Name: <unnamed>       Type: pptpgre         ID: 0000002e   Num hooks: 2
  Name: mpd1899-mss     Type: tcpmss          ID: 0000002d   Num hooks: 4
  Name: mpd1899-vpn-bpf Type: bpf             ID: 0000002c   Num hooks: 5
  Name: mpd1899-vpn-vjc Type: vjc             ID: 0000002b   Num hooks: 4
  Name: mpd1899-vpn     Type: ppp             ID: 0000002a   Num hooks: 8
  Name: ng0             Type: iface           ID: 00000029   Num hooks: 2
  Name: mpd1899-vpn-so  Type: socket          ID: 00000028   Num hooks: 2
  Name: fxp0            Type: ether           ID: 00000002   Num hooks: 0
  Name: rl0             Type: ether           ID: 00000001   Num hooks: 1

Any ideas what to do next?

Thanks in advance, Nikos