Re: [RFC] Allowing non-root to get iptables info?

[Patrick McHardy <kaber@trash.net>]

[Adding Stephen back to CC list]

Jozsef Kadlecsik wrote:
> On Wed, 27 Feb 2008, Patrick McHardy wrote:
> 
>> Micha? Miros?aw wrote:
>>> On Wed, Feb 27, 2008 at 12:52:52PM +0100, Patrick McHardy wrote:
>>>> Stephen Hemminger wrote:
>>>>> Is there any strong reason why checking the status of iptables is
>>>>> restricted?
>>>>>
>>>>> Vyatta makes a distribution for routers. In our case, we use a non-root
>>>>> account
>>>>> for operator commands, and some of the commands are about querying
>>>>> iptables status.
>>>>> It seems to be less risky to just fix the kernel to allow non-root user
>>>>> to query rules
>>>>> than the current script that uses sudo. Another alternative would be
>>>>> building a special
>>>>> restricted command that could be setuid root, but just changing the
>>>>> kernel seems easiest.
>>>> I always thought of it as a privacy thing, similar to restricting
>>>> /proc/net/nf_conntrack. But since iptables rules usually don't
>>>> allow you to determine active connections just from the packet
>>>> counters that might be overkill. So I don't see any real harm
>>>> in allowing users to list the ruleset.
>>> At least for iptables, reading of iptables status can be done by making
>>> iptables-save setuid-root. So I think no kernel patching is necessary.
>> Thats true, but I wouldn't do that since iptables is not the
>> most trustworthy code.
> 
> I'd be more happy with a module parameter and/or proc switch by which this 
> new feature could be enabled. So backward compatibility could be kept and 
> the users could list the rules only if the system is explicitly configured 
> to allow it.


I don't think compatibility is a problem here, lifting this
restriction can't possibly break anything in userspace.

The question is more whether this causes privacy or other issues,
if yes, we shouldn't do it, otherwise there's no harm in doing
in unconditionally. I personally don't see any problems with
this change.