To properly match iif in ip rules we have to provide
LOOPBACK_IFINDEX in flowi6_iif, not 0. Some ip6mr_fib_lookup
and fib6_rule_lookup callers need such fix.
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>
 {
        struct mr6_table *mrt;
        struct flowi6 fl6 = {
-               .flowi6_iif     = skb->skb_iif,
+               .flowi6_iif     = skb->skb_iif ? : LOOPBACK_IFINDEX,
                .flowi6_oif     = skb->dev->ifindex,
                .flowi6_mark    = skb->mark,
        };
 
        struct ipv6hdr *iph = ipv6_hdr(skb);
        bool ret = false;
        struct flowi6 fl6 = {
+               .flowi6_iif = LOOPBACK_IFINDEX,
                .flowlabel = (* (__be32 *) iph) & IPV6_FLOWINFO_MASK,
                .flowi6_proto = iph->nexthdr,
                .daddr = iph->saddr,
 
        struct flowi6 fl6;
 
        memset(&fl6, 0, sizeof(fl6));
+       fl6.flowi6_iif = LOOPBACK_IFINDEX;
        fl6.flowi6_oif = oif;
        fl6.flowi6_mark = mark;
        fl6.daddr = iph->daddr;
        struct flowi6 fl6;
 
        memset(&fl6, 0, sizeof(fl6));
+       fl6.flowi6_iif = LOOPBACK_IFINDEX;
        fl6.flowi6_oif = oif;
        fl6.flowi6_mark = mark;
        fl6.daddr = msg->dest;