xtables-addons - problem including nf_nat.h in userspace plugin

xtables-addons - problem including nf_nat.h in userspace plugin

[Marek Kierdelewicz]

Hi,

I'm writing a new netfilter module and I'm using xtables-addons
infrastructure version 1.31 as described in paragraph 2.9.1 of
"Writing Netfilter modules" ebook[1]. 

Iptables userspace plugin for the module needs definition of "struct
nf_nat_multi_range", so I added following line to libxt_xxxx.c:
#include <net/netfilter/nf_nat.h>

Unfortunately I get following message during make: 
warning: net/netfilter/nf_nat.h: No such file or directory
... and compilation fails.

I was able to make it work by copying nf_nat.h and nf_conntrack_tuple.h
to extension directory in xtables-addons tree and by modifying include
in libxt_xxxx.c to "nf_nat.h", but this doesn't seem to be the proper
way of doing things.

How can I make it work without copying header files to xtables-addons
tree?

Please CC me in reply as I'm not subscribed to netfilter-devel. Thx!

[1] http://jengelh.medozas.de/documents/Netfilter_Modules.pdf

Best regards,
Marek

Re: xtables-addons - problem including nf_nat.h in userspace plugin

[Jan Engelhardt]

On Sunday 2010-11-21 22:47, Marek Kierdelewicz wrote:
>
>I'm writing a new netfilter module and I'm using xtables-addons[...]
>Iptables userspace plugin for the module needs definition of "struct
>nf_nat_multi_range", so I added following line to libxt_xxxx.c:
>#include <net/netfilter/nf_nat.h>
>Unfortunately I get following message during make: 
>warning: net/netfilter/nf_nat.h: No such file or directory
>... and compilation fails.
>I was able to make it work by copying nf_nat.h and nf_conntrack_tuple.h
>to extension directory in xtables-addons tree and by modifying include
>in libxt_xxxx.c to "nf_nat.h", but this doesn't seem to be the proper
>way of doing things.

Well, iptables also copies them rather than properly relying on
something from <linux/*>. Yes, it's not proper. Patrick should know
the details about the what and why.

As for xt-a, preferable location is

linux-src/include/net/netfilter/nf_nat.h ->
xtables-addons/include/net/netfilter/nf_nat.h

Then #include <net/...> should work.

Re: xtables-addons - problem including nf_nat.h in userspace plugin

[Patrick McHardy]

On 22.11.2010 14:52, Jan Engelhardt wrote:
> 
> On Sunday 2010-11-21 22:47, Marek Kierdelewicz wrote:
>>
>> I'm writing a new netfilter module and I'm using xtables-addons[...]
>> Iptables userspace plugin for the module needs definition of "struct
>> nf_nat_multi_range", so I added following line to libxt_xxxx.c:
>> #include <net/netfilter/nf_nat.h>
>> Unfortunately I get following message during make: 
>> warning: net/netfilter/nf_nat.h: No such file or directory
>> ... and compilation fails.
>> I was able to make it work by copying nf_nat.h and nf_conntrack_tuple.h
>> to extension directory in xtables-addons tree and by modifying include
>> in libxt_xxxx.c to "nf_nat.h", but this doesn't seem to be the proper
>> way of doing things.
> 
> Well, iptables also copies them rather than properly relying on
> something from <linux/*>. Yes, it's not proper. Patrick should know
> the details about the what and why.

Mainly to allow to compile new extensions before the kernel headers
are updated. Including files from include/net is wrong though, they
should be moved to include/linux instead.

Re: xtables-addons - problem including nf_nat.h in userspace plugin

[Marek Kierdelewicz]

Hi,

>As for xt-a, preferable location is
>linux-src/include/net/netfilter/nf_nat.h ->
>xtables-addons/include/net/netfilter/nf_nat.h
>Then #include <net/...> should work.

Thx! That worked great.

Best regards,
Marek