netfilter: xt_CT: recover NOTRACK target support

Florian Westphal reported that the removal of the NOTRACK target
(9655050 netfilter: remove xt_NOTRACK) is breaking some existing
setups.

That removal was scheduled for removal since long time ago as
described in Documentation/feature-removal-schedule.txt

What:  xt_NOTRACK
Files: net/netfilter/xt_NOTRACK.c
When:  April 2011
Why:   Superseded by xt_CT

Still, people may have not notice / may have decided to stick to an
old iptables version. I agree with him in that some more conservative
approach by spotting some printk to warn users for some time is less
agressive.

Current iptables 1.4.16.3 already contains the aliasing support
that makes it point to the CT target, so upgrading would fix it.
Still, the policy so far has been to avoid pushing our users to
upgrade.

As a solution, this patch recovers the NOTRACK target inside the CT
target and it now spots a warning.

Reported-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/net/netns/x_tables.h b/include/net/netns/x_tables.h
index 591db7d657a3..c24060ee411e 100644
--- a/include/net/netns/x_tables.h
+++ b/include/net/netns/x_tables.h
@@ -8,6 +8,7 @@ struct ebt_table;
 
 struct netns_xt {
         struct list_head tables[NFPROTO_NUMPROTO];
+        bool notrack_deprecated_warning;
 #if defined(CONFIG_BRIDGE_NF_EBTABLES) || \
     defined(CONFIG_BRIDGE_NF_EBTABLES_MODULE)
         struct ebt_table *broute_table;