inet6_opt_append
extern int inet6_opt_append(void *, socklen_t, int, uint8_t, socklen_t,
if (inet6_opt_append(buf, sizeof (buf), 120, IP6OPT_NSAP_ADDR, 10, 1,
int rval = inet6_opt_append(NULL, 0, t->i6a_off, t->i6a_type,
extern int inet6_opt_append(void *extbuf, socklen_t extlen, int offset,