IP6SKB_FORWARDED
likely(!(IP6CB(skb)->flags & IP6SKB_FORWARDED))) {
!(IP6CB(skb)->flags & IP6SKB_FORWARDED)) ||
IP6CB(skb)->flags |= IP6SKB_FORWARDED;
if (IP6CB(skb)->flags & IP6SKB_FORWARDED)
IP6CB(skb)->flags = IP6SKB_FORWARDED;