getcredhostname
getcredhostname(td->td_ucred, utsname.nodename, LINUX_MAX_UTSNAME);
getcredhostname(curthread->td_ucred, hostbuf,
getcredhostname(curthread->td_ucred, hostbuf, sizeof(hostbuf));
getcredhostname(td->td_ucred, hostname,
getcredhostname(NULL, oh_space + oh_len, 32 - oh_len);
getcredhostname(NULL, hostbuf, sizeof(hostbuf));
void getcredhostname(struct ucred *, char *, size_t);