netfilter: nf_conntrack: add generic function to get len of generic policy

Usefull for all protocols which do not add additional data, such
as GRE or UDPlite.

Signed-off-by: Holger Eitzenberger <holger@eitzenberger.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>

2 files changed, 7 insertions, 0 deletions

diff --git a/include/net/netfilter/nf_conntrack_l4proto.h b/include/net/netfilter/nf_conntrack_l4proto.h
index a120990b3b2b..ba32ed7bdabe 100644
--- a/include/net/netfilter/nf_conntrack_l4proto.h
+++ b/include/net/netfilter/nf_conntrack_l4proto.h
@@ -113,6 +113,7 @@ extern int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb,
                                       const struct nf_conntrack_tuple *tuple);
 extern int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
                                       struct nf_conntrack_tuple *t);
+extern int nf_ct_port_nlattr_tuple_size(void);
 extern const struct nla_policy nf_ct_port_nla_policy[];
 
 #ifdef CONFIG_SYSCTL
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index c55bbdc7d429..b182b30c7d8d 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -921,6 +921,12 @@ int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
         return 0;
 }
 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_to_tuple);
+
+int nf_ct_port_nlattr_tuple_size(void)
+{
+        return nla_policy_len(nf_ct_port_nla_policy, CTA_PROTO_MAX + 1);
+}
+EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_tuple_size);
 #endif
 
 /* Used by ipt_REJECT and ip6t_REJECT. */