Cannot use iptable extensions

Samuel Jean sj-netfilter at
Mon Sep 20 22:21:27 CEST 2004

On Mon, September 20, 2004 11:28 am, Samuel Jean said:
> On Mon, September 20, 2004 4:20 am, d l said:
>> Hi,
>> I am using vanilla Fedora Core 2, without configuring
>> firewall in anaconda during initial install.
> Custom compiled kernel ?
>> Simple rules seems to works with built in modules. e.g.
>> iptables -A INPUT -p ICMP -j DROP
>> However when I tried to use extension modules like
>> <connlimit> and <owner>, iptables always gives me error.
>> For <owner>:
>> iptables -m owner --help
>> .......
>> OWNER match v1.2.9 options:
>> [!] --uid-owner userid     Match local uid
>> [!] --gid-owner groupid    Match local gid
>> [!] --pid-owner processid  Match local pid
>> [!] --sid-owner sessionid  Match local sid
>> [!] --cmd-owner name       Match local command name
> When you get the help displayed, the dynamic library is properly
> installed.
>> # iptables -A INPUT -m owner --cmd-owner mlnet -j test
>> iptables: Invalid argument
> That means the dynamic library is using a structure different from the one
> used by the module.
> If no module was present, you would get the
> "No match/chain/target by that name" error.
> So your module is there but at the time of loading the rule, it compares
> the size of structure it uses against the one your dynamic library uses.
> When there`s something wrong in the checkentry function, iptables simply
> says "iptables: Invalid arguments"
> Most of the time, you have a newer library than your module is.
> Patch applied with pom-ng should take care of fixing your problem
> if you do recompile the iptables userspace as well as the kernel
> netfilter's module.

In addition, most of the netfilter's modules are logging via syslog
whenever there`s something wrong while doing their 'checkentry'.

Take a look at /var/log/syslog just in case.

Personally, I've never used/tried that match.  So, could it be that you
are loading it in the wrong chain (not supported by the module) ?

Good luck,

Samuel Jean

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