__in6_dev_get_safely
idev = __in6_dev_get_safely(dev);
__in6_dev_get_safely(dev), IPSTATS_MIB_INMCAST,
idev = __in6_dev_get_safely(dev_get_by_index_rcu(net, IP6CB(skb)->iif));
idev = __in6_dev_get_safely(dev_get_by_index_rcu(net, IP6CB(skb)->iif));
struct inet6_dev *idev = __in6_dev_get_safely(skb->dev);