svc_getcred
if (!svc_getcred(rqst, &nd.nd_cred, &credflavor)) {
if (!svc_getcred(rqst, &nd.nd_cred, &credflavor)) {
if (!svc_getcred(rqstp, &cred, NULL)) {
extern int svc_getcred(struct svc_req *, struct ucred **, int *);