diff --git a/include/net/rtnetlink.h b/include/net/rtnetlink.h
index dce7072..086fa9e8 100644
--- a/include/net/rtnetlink.h
+++ b/include/net/rtnetlink.h
@@ -15,4 +15,12 @@
 extern void	rtnl_unregister_all(int protocol);
 extern int	rtnl_dump_all(struct sk_buff *skb, struct netlink_callback *cb);
 
+static inline int rtnl_msg_family(struct nlmsghdr *nlh)
+{
+	if (nlmsg_len(nlh) >= sizeof(struct rtgenmsg))
+		return ((struct rtgenmsg *) nlmsg_data(nlh))->rtgen_family;
+	else
+		return AF_UNSPEC;
+}
+
 #endif