+
+ // must vet call_id here, all others vetted by workhorse mt_call() function
+ if( call_id > MAX_CALL_ID || call_id < 2 ) { // 0 and 1 are reserved; user app cannot supply them
+ mbuf->state = RMR_ERR_BADARG;
+ mbuf->tp_state = EINVAL;
+ return mbuf;
+ }
+