ipv6: add ip6_route_lookup

like rt6_lookup, but allows caller to pass in flowi6 structure.
Will be used by the upcoming ipv6 netfilter reverse path filter
match.

Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

include/net/ip6_route.h

@@ -70,6 +70,8 @@ extern void			ip6_route_input(struct sk_buff *skb);
 extern struct dst_entry *	ip6_route_output(struct net *net,
 						 const struct sock *sk,
 						 struct flowi6 *fl6);
+extern struct dst_entry *	ip6_route_lookup(struct net *net,
+						 struct flowi6 *fl6, int flags);
 
 extern int			ip6_route_init(void);
 extern void			ip6_route_cleanup(void);

net/ipv6/route.c

@@ -658,6 +658,13 @@ out:
 
 }
 
+struct dst_entry * ip6_route_lookup(struct net *net, struct flowi6 *fl6,
+				    int flags)
+{
+	return fib6_rule_lookup(net, fl6, flags, ip6_pol_route_lookup);
+}
+EXPORT_SYMBOL_GPL(ip6_route_lookup);
+
 struct rt6_info *rt6_lookup(struct net *net, const struct in6_addr *daddr,
 			    const struct in6_addr *saddr, int oif, int strict)
 {