Correct argument to slurm_ping() in scontrol.

Don't authenticate most RPCs processed by backup controller (only
check SHUTDOWN, etc.).

src/slurmctld/controller.c

@@ -2327,27 +2327,28 @@ static int _background_process_msg(slurm_msg_t * msg)
 {
 	int error_code = SLURM_SUCCESS;
 	uid_t uid;
+	bool super_user = false;
 
 	uid = g_slurm_auth_get_uid(msg->cred);
-	if ((uid != 0) && (uid != getuid())) {
-		error("Security violation, SHUTDOWN RPC from uid %u",
-		      (unsigned int) uid);
-		error_code = ESLURM_USER_ID_MISSING;
-	}
+	if ((uid == 0) || (uid == getuid()))
+		super_user = true;
 
 	if (error_code == SLURM_SUCCESS) {
 		if (msg->msg_type == REQUEST_PING) {
 			;
-		} else if (msg->msg_type == REQUEST_SHUTDOWN_IMMEDIATE) {
-			debug3
-			    ("Performing RPC: REQUEST_SHUTDOWN_IMMEDIATE");
-		} else if (msg->msg_type == REQUEST_SHUTDOWN) {
+		} else if (super_user && 
+			   (msg->msg_type == REQUEST_SHUTDOWN_IMMEDIATE)) {
+			debug3("Performing RPC: REQUEST_SHUTDOWN_IMMEDIATE");
+		} else if (super_user && 
+			   (msg->msg_type == REQUEST_SHUTDOWN)) {
 			debug("Performing RPC: REQUEST_SHUTDOWN");
 			pthread_kill(thread_id_sig, SIGTERM);
-		} else if (msg->msg_type == REQUEST_CONTROL) {
+		} else if (super_user && 
+			   (msg->msg_type == REQUEST_CONTROL)) {
 			debug3("Ignoring RPC: REQUEST_CONTROL");
 		} else {
-			error("Invalid RPC received %d", msg->msg_type);
+			error("Invalid RPC received %d from uid %u", 
+			      msg->msg_type, uid);
 			error_code = SLURM_COMMUNICATIONS_RECEIVE_ERROR;
 		}
 	}