IN_LOOPBACK 292 include/uapi/linux/in.h #define IN_LOOPBACK(a) ((((long int) (a)) & 0xff000000) == 0x7f000000) IN_LOOPBACK 292 tools/include/uapi/linux/in.h #define IN_LOOPBACK(a) ((((long int) (a)) & 0xff000000) == 0x7f000000)