Re: Fix --with-kernel for libnfnetlink

[Amin Azez <azez@ufomechanic.net>]

Sorry to bring this up again...

* Pablo Neira Ayuso wrote, On 21/04/06 12:09:
> Why do you need this parameter? the netfilter libraries don't require
> kernel headers anymore since they are already bundled in the package
> provided. For example, see include/libnfnetlink/linux_nfnetlink.h. We
> have had several problems with iptables and the kernel headers in the
> past: compilation warnings, breakages... That is the reason why we
> decided to do so.
> 
> On the other hand, autogen.sh automates the copy of these headers,
> so you could choose them via KERNEL_DIR but you need some important
> reason to do that.


Current (svn) autogen.sh is hard wired to use the currently booted kernel.

I'm all for not keeping a copy in the SVN tree, but why presume that the
one in the booted kernel is the one we want? Isn't this just another
reason to have --with-kernel back; as we are not copying old userland
so-called kernel header files?

Since my 2.6.11 work (which is booted) I'm now working towards 2.6.17,
and the differences are:

-#define NFNL_SUBSYS_CTHELPER           5
-#define NFNL_SUBSYS_COUNT              6
+#define NFNL_SUBSYS_COUNT              5

 #ifdef __KERNEL__

@@ -165,6 +164,7 @@
        __res;                                                          \
 })

+extern int nfnetlink_has_listeners(unsigned int group);


Which seem important; it is a mistake for autogen.sh to have copied the
file for the booted kernel.

I did wonder if libnfnetlink should use text labels instead of symbols,
and have the dynamic (or at least unpredicatbale) values fetched from
the kernel and stored as int's instead of constants in libnfnetlink

It would solve this problem.

Sam