Interface auto-cloning bug or feature?

[Maxim Sobolev]

Alexey Shuvaev wrote:
> On Fri, Sep 19, 2008 at 04:33:19AM -0700, Maxim Sobolev wrote:
>> Alexey Shuvaev wrote:
>>>> [root at sp1 /usr/home/sobomax]# ifconfig -a
>>>> tun0: flags=8010<POINTOPOINT,MULTICAST> mtu 1500
>>>> tun1: flags=8010<POINTOPOINT,MULTICAST> mtu 1500
>>>> tun2: flags=8010<POINTOPOINT,MULTICAST> mtu 1500
>>>> tun3: flags=8010<POINTOPOINT,MULTICAST> mtu 1500
>>>>
>>> Me too.
>>> I have seen that using ppp(8) and security/vpnc.
>> That what has caused me to look into this issue. You can find patch for  
>> security/vpnc to prevent unbounded interface cloning here:
>>
>> http://sobomax.sippysoft.com/~sobomax/vpnc.diff
>>
> Ok, the patch prevents interface cloning, but I think it doesn't solve
> the actual problem.

Well, in any case checking kernel modules list to detect if_tun presence 
is more correct way than doing stat on /dev/tun.

-Maxim