netfilter: netns nf_conntrack: per-netns event cache

Heh, last minute proof-reading of this patch made me think,
that this is actually unneeded, simply because "ct" pointers will be
different for different conntracks in different netns, just like they
are different in one netns.

Not so sure anymore.

[Patrick: pointers will be different, flushing can only be done while
 inactive though and thus it needs to be per netns]

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
diff --git a/include/net/netns/conntrack.h b/include/net/netns/conntrack.h
index 6ddf58e..9d5c162 100644
--- a/include/net/netns/conntrack.h
+++ b/include/net/netns/conntrack.h
@@ -4,12 +4,17 @@
 #include <linux/list.h>
 #include <asm/atomic.h>
 
+struct nf_conntrack_ecache;
+
 struct netns_ct {
 	atomic_t		count;
 	unsigned int		expect_count;
 	struct hlist_head	*hash;
 	struct hlist_head	*expect_hash;
 	struct hlist_head	unconfirmed;
+#ifdef CONFIG_NF_CONNTRACK_EVENTS
+	struct nf_conntrack_ecache *ecache;
+#endif
 	int			hash_vmalloc;
 	int			expect_vmalloc;
 };