ip_check_mc_rcu
extern int ip_check_mc_rcu(struct in_device *dev, __be32 mc_addr, __be32 src_addr, u8 proto);
our = ip_check_mc_rcu(in_dev, daddr, saddr,
our = ip_check_mc_rcu(l3_in_dev, daddr, saddr,
if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
ours = ip_check_mc_rcu(in_dev, iph->daddr, iph->saddr,