kh
union kh kh;
#define KLH_PRIVSET(kh) ((priv_set_t *)(((kh)->klh_privoff == 0 ? NULL : \
(char *)(kh) + (kh)->klh_privoff)))
#define KLH_ARG(kh) ((void *)((kh)->klh_argoff != 0 ? \
(char *)(kh) + (kh)->klh_argoff : NULL))