netfilter: nf_conntrack: Add a struct net parameter to l4_pkt_to_tuple

As gre does not have the srckey in the packet gre_pkt_to_tuple
needs to perform a lookup in it's per network namespace tables.

Pass in the proper network namespace to all pkt_to_tuple
implementations to ensure gre (and any similar protocols) can get this
right.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
diff --git a/include/net/netfilter/nf_conntrack.h b/include/net/netfilter/nf_conntrack.h
index e8ad468..d642f68 100644
--- a/include/net/netfilter/nf_conntrack.h
+++ b/include/net/netfilter/nf_conntrack.h
@@ -191,7 +191,8 @@
 bool nf_ct_delete(struct nf_conn *ct, u32 pid, int report);
 
 bool nf_ct_get_tuplepr(const struct sk_buff *skb, unsigned int nhoff,
-		       u_int16_t l3num, struct nf_conntrack_tuple *tuple);
+		       u_int16_t l3num, struct net *net,
+		       struct nf_conntrack_tuple *tuple);
 bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
 			  const struct nf_conntrack_tuple *orig);