+# OK. We're good
+# Only, slices are allowed only 1 port reservation/session
+
+if ( -f "/dev/shm/$slicename-port" ) {
+ print "You have already reserved the following port:\n";
+ system("cat /dev/shm/$slicename-port");
+ exit(1);
+}
+
+open FIL,">/dev/shm/$slicename-port";
+print FIL "$portnumber";
+close FIL;
+
+system("iptables -t mangle -A INPUT -m tcp -p tcp --dport $portnumber -j MARK --set-mark $xid");