#define TR_NAME 17 /* 1 + max ioctl message size */ struct trc { char tr_name[TR_NAME]; /* user supplied name for trace messages */ short tr_state; /* internal state */ int tr_mask; /* block type trace mask */ }; /* * values for tr_state field: */ #define TR_USE 1 /* trc structure in use */ /* * Ioctl message format. */ struct trcioc { int command; union { int mask; char name[16]; } arg; };