IN_CLASSB 256 include/uapi/linux/in.h #define IN_CLASSB(a) ((((long int) (a)) & 0xc0000000) == 0x80000000) IN_CLASSB 256 tools/include/uapi/linux/in.h #define IN_CLASSB(a) ((((long int) (a)) & 0xc0000000) == 0x80000000)