__NEIGH_VAR
#define NEIGH_VAR_PTR(p, attr) (&(__NEIGH_VAR(p, attr)))
#define NEIGH_VAR_INIT(p, attr, val) (__NEIGH_VAR(p, attr) = val)
#define NEIGH_VAR(p, attr) READ_ONCE(__NEIGH_VAR(p, attr))