NIFBITS 56 include/uapi/linux/mroute6.h if_mask ifs_bits[DIV_ROUND_UP(IF_SETSIZE, NIFBITS)]; NIFBITS 59 include/uapi/linux/mroute6.h #define IF_SET(n, p) ((p)->ifs_bits[(n)/NIFBITS] |= (1 << ((n) % NIFBITS))) NIFBITS 60 include/uapi/linux/mroute6.h #define IF_CLR(n, p) ((p)->ifs_bits[(n)/NIFBITS] &= ~(1 << ((n) % NIFBITS))) NIFBITS 61 include/uapi/linux/mroute6.h #define IF_ISSET(n, p) ((p)->ifs_bits[(n)/NIFBITS] & (1 << ((n) % NIFBITS)))