Re: iptc_* implementation queries

[Michael Kearey <mutk@iprimus.com.au>]

Jambunathan Jambunathan wrote:
> I am interested in knowing the netfilter infrastructure and I would
> like to know how iptables communicates with netfilter ( user to
> kernel space communication ) I understand that it happens through
> raw sockets through setsockot and getsockopt. Also there are a
> good number of iptc_* calls that are declared in libiptc.h which
> are used by the iptables user space tool. I would like to know 
> where I can see the implementations for these iptc_* calls. 
> I am unable to see this either in the kernel code nor in the
> iptables bz2 package. I am looking at 2.4.18 code of linux
> kernel fyi.
> 
> I will appreciate a mini code walk through or example.
> 

(Jambunathan sorry about replying directly to you..here is message to 
list)

Here is a reasonably good 'walk through'. It's ever so slightly 
inaccurate in some of the example code with redundant #includes, but 
is pretty good as a starting point. It really should 'This is how *I* 
did it', as there are several ways to acheive same thing...


http://www.tldp.org/HOWTO/Querying-libiptc-HOWTO/index.html


BTW, the libiptc isn't meant to be used as an 'API' to manipulate 
tables etc. Several reasons are given see 
http://netfilter.org/documentation/FAQ/netfilter-faq-4.html#ss4.5

Cheers,
Michael