Re: comments on CML 1.1.0

[Harald Welte <laforge@gnumonks.org>]

On Sat, Apr 14, 2001 at 03:51:53PM -0400, Eric S. Raymond wrote:
> jeff millar <jeff@wa1hco.mv.com>:
> > Selecting IP_NF_COMPAT_IPCHAINS turns off IP_NF_CONNTRACK and friends.  But,
> > I think CML1, allowed both support to the new iptables and compatibility
> > modes to allow old ipchains scripts to work with the new kernel.
> 
> Would somebody who knows what these dependencies are please send me a rule
> patch?

Ok, as I am one of the netfilter people, and I've already cleaned up this 
issue after Linus' switch to the 'new-style' Makefiles somewhen in 2.4.0-textXX
I might be suitable for this job. 

Unfortunately I don't know too much about CML2, so I cannot provide you with
a straightforward ruleset, only with a description:

Basically there are the following dependencies:

1. you compile connection tracking as module
	a) iptables compiled as module
		- you can compile ANY or BOTH of ipchains, ipfwadm as 
		  module ONLY (not static)
	b) iptables compiled static
		- NO possibility of compiling ipchains or ipfwadm at all,
		  either as module or static
	c) iptables NOT compiled at all
		- you can compile ONE OF ipchains, ipfwadm statically
		- you can compile BOTH of them as modules

2. you compile connection tracking statically into the kernel
	- NO possibility of compiling ipchains or ipfwadm at all,
	  either module or static
	- iptables can be compiled modular or static


there's another interesting dependency, I'll describe the problem first:

Netfilter has modules called connection tracking and nat helpers. For
most protocols, they will appear in pairs (as opposed to only one module
called ip_masq_XXX in 2.2.x). They are performing independent functionality,
and you will never need the NAT helper on a non-nat box.

1. connection tracking (CONFIG_IP_NF_CONNTRACK) is on (M or Y)
   Full NAT (CONFIG_IP_NF_NAT) off
	- if CONFIG_IP_NF_FTP is OFF, none of ip_conntrack_ftp.c/ip_nat_ftp.c
	  are compiled
	- if CONFIG_IP_NF_FTP is ON (M or Y), ip_conntrcak_ftp.c is compiled
	  (as module or statically, as apropriate)
2. connection tracking is on (M or Y), Full NAT is on (M or Y)
	- if CONFIG_IP_NF_FTP is OFF, none of ip_conntrack_ftp.c/ip_nat_ftp.c
	  are compiled
	- if CONFIG_IP_NF_FTP is ON (M or Y), both ip_conntrack_ftp.c AND
	  ip_nat_ftp.c are compiled (module or static, as user wishes)


I'm asking myself if we now should be proud of having the most complicated
dependencies of the whole kernel ;)

-- 
Live long and prosper
- Harald Welte / laforge@gnumonks.org                http://www.gnumonks.org
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