Re: [PATCH nf-next 1/4] netfilter: nf_conntrack_tuple_common.h: fix #include

[Davide Caratti <dcaratti@redhat.com>]

On Fri, 2016-11-11 at 12:07 +0200, Mikko Rapeli wrote:
> I assume also with this change it is ok to include both
> <linux/netfilter.h>
> and <linux/netfilter/nf_conntrack_tuple_common.h> userspace but what was
> the
> kernel compile error with include/net/netns/conntrack.h and
> ip_conntrack_dir?

hi Mikko, thank you for looking at this!

The problem is in patch 3/4 as I added #include
<linux/netfilter/nf_conntrack_sctp.h>  in include/net/netns/conntrack.h,
but I saw similar things also with DCCP.

<...>
  CC      kernel/sysctl_binary.o
In file included from ./include/linux/netfilter.h:14:0,
                 from ./include/uapi/linux/netfilter/nf_conntrack_tuple_common.h:5,
                 from ./include/uapi/linux/netfilter/nf_conntrack_sctp.h:5,
                 from ./include/linux/netfilter/nf_conntrack_sctp.h:5,
                 from ./include/net/netns/conntrack.h:13,
                 from ./include/net/net_namespace.h:25,
                 from ./include/linux/init_task.h:15,
                 from init/init_task.c:1:
./include/linux/netdevice.h:1859:2: error: unknown type name ‘possible_net_t’
  possible_net_t   nd_net;
  ^	
(possile_net_t is in net_namespace.h).

> Is there a kernel side conflict between uapi and net/netns headers?

Looks like a circular dependency is here, or nf_conntrack_tuple_common.h
is including the wrong netfilter.h. From within net/netns/conntrack.h I
can include only those UAPI files that don't include <linux/netfilter.h>
(for example, nf_conntrack_tcp.h that uses '2' instead of IP_CT_DIR_MAX).

Do you have any suggestion?
thank you in advance,
--
davide