xfrm: Add oif to dst lookups

Rules can be installed that direct route lookups to specific tables based
on oif. Plumb the oif through the xfrm lookups so it gets set in the flow
struct and passed to the resolver routines.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
diff --git a/net/ipv6/xfrm6_policy.c b/net/ipv6/xfrm6_policy.c
index ed0583c..a74013d 100644
--- a/net/ipv6/xfrm6_policy.c
+++ b/net/ipv6/xfrm6_policy.c
@@ -26,7 +26,7 @@
 
 static struct xfrm_policy_afinfo xfrm6_policy_afinfo;
 
-static struct dst_entry *xfrm6_dst_lookup(struct net *net, int tos,
+static struct dst_entry *xfrm6_dst_lookup(struct net *net, int tos, int oif,
 					  const xfrm_address_t *saddr,
 					  const xfrm_address_t *daddr)
 {
@@ -35,6 +35,7 @@
 	int err;
 
 	memset(&fl6, 0, sizeof(fl6));
+	fl6.flowi6_oif = oif;
 	memcpy(&fl6.daddr, daddr, sizeof(fl6.daddr));
 	if (saddr)
 		memcpy(&fl6.saddr, saddr, sizeof(fl6.saddr));
@@ -50,13 +51,13 @@
 	return dst;
 }
 
-static int xfrm6_get_saddr(struct net *net,
+static int xfrm6_get_saddr(struct net *net, int oif,
 			   xfrm_address_t *saddr, xfrm_address_t *daddr)
 {
 	struct dst_entry *dst;
 	struct net_device *dev;
 
-	dst = xfrm6_dst_lookup(net, 0, NULL, daddr);
+	dst = xfrm6_dst_lookup(net, 0, oif, NULL, daddr);
 	if (IS_ERR(dst))
 		return -EHOSTUNREACH;