[Click] Question: Script "cat" handler considered dangerous?

[Eddie Kohler]

Hi Bart,

Bart Braem wrote:
> Hi Eddie,
> 
> Could you give an example of where this might be useful? I think there  
> is a large coupling between your system and your router if you need  
> this, but perhaps I'm mistaken.

It's been useful for me in tests.  See the 
test/ethernet/ARPQuerier-03.testie test, for example.

> I personally think it's dangerous, as a ControlSocket has no  
> authentication at all. For now that's not really a problem because of  
> the limited capabilities of a router,

Ouch ouch ouch!  I would NOT think that way!  ControlSocket is meant for 
debugging, and if you have access to ControlSocket you can, for example, 
stop the router, which is a DoS attack at the least.  You can make 
ControlSocket safe in a couple ways; provide a PROXY, make it READONLY, 
make it a Unix socket, use something I just checked in, the LOCALHOST 
option.

Nevertheless, I've gone ahead and made the "cat" handler private.

Eddie


> but it would become more  
> dangerous. We would have to be very careful not to write any code that  
> might result in that script being called. Also in new elements...
> 
> On the other hand, if one already runs Click as root, you should know  
> the implied dangers.
> 
> Regards,
> Bart