Re: Create new NetFilter table

From: Victor Porton
Date: Fri Jan 10 2014 - 14:52:50 EST




10.01.2014, 21:39, "Joshua Brindle" <brindle@xxxxxxxxxxxxxxxxx>:
> Victor Porton wrote:
>
>>  I propose to create a new NetFilter table dedicated to rules created programmatically (not by explicit admin's iptables command).
>>
>>  Otherwise an admin could be tempted to say `iptables -F security` which would probably break rules created for example by sandboxing software (which may follow same-origin policy to restrict one particular program to certain domain and port only). Note that in this case `iptables -F security` is a security risk (sandbox breaking)?
>>
>>  New table could be possibly be called:
>>
>>  - temp
>>  - temporary
>>  - auto
>>  - automatic
>>  - volatile
>>  - daemon
>>  - system
>>  - sys
>>
>>  In iptables docs it should be said that this table should not be manipulated manually.
>
> Is it possible that the solution to your sandboxing problem is seccomp
> filter?
>
> http://outflux.net/teach-seccomp/
>
> You'd filter out any syscall that can make outbound connections and then
> only pass already opened sockets to the sandboxed threads?
>
> seccomp filter was actually created for sandboxing, so that user
> applications could voluntarily shed the ability to call certain syscalls
> before handling untrusted data.

seccomp would not work for me, because I need network enabled sandboxes. Moreover we should be able to filter out certain subnets such as 127.0.0.0/255.0.0.0 (and others), This cleanly can't be done with seccomp.

--
Victor Porton - http://portonvictor.org
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