host_realm
krb5_hostrealm_host_realm_fn host_realm;
if (h->vt.host_realm == NULL)
return h->vt.host_realm(context, h->data, host, realms_out);
ret = host_realm(context, *hp, cleanname, &realms);
vt->host_realm = profile_host_realm;
vt->host_realm = split_comps;
vt->host_realm = maybe_realm;