IFCAP_B_SIZE
#ifdef IFCAP_B_SIZE
_Static_assert(sizeof(ifcap_bit_names) >= IFCAP_B_SIZE * sizeof(char *),
uint32_t active_caps[roundup2(IFCAP_B_SIZE, 32) / 32] = {};
uint32_t all_caps[roundup2(IFCAP_B_SIZE, 32) / 32] = {};
nlattr_add_u32(nw, NLA_BITSET_SIZE, IFCAP_B_SIZE);