RTNL_FAMILY_MAX
static struct rtnl_link __rcu *__rcu *rtnl_msg_handlers[RTNL_FAMILY_MAX + 1];
BUG_ON(protocol < 0 || protocol > RTNL_FAMILY_MAX);
for (idx = 1; idx <= RTNL_FAMILY_MAX; idx++) {
BUG_ON(protocol < 0 || protocol > RTNL_FAMILY_MAX);
BUG_ON(protocol < 0 || protocol > RTNL_FAMILY_MAX);