Add check to make sure that pcvm nodes are used as edge nodes only

(only 1 lan/link connection). An interim solution until we solve the
routing problem for "virtual" router nodes completely. Also added a
new global "enforce_user_restrictions" that you can set in your .ns
file to turn of this check, and some others.

tbsetup/ns2ir/node.tcl

@@ -127,6 +127,7 @@ Node instproc updatedb {DB} {
     var_import ::GLOBALS::pid
     var_import ::GLOBALS::eid
     var_import ::GLOBALS::default_ip_routing_type
+    var_import ::GLOBALS::enforce_user_restrictions
     
     # If we haven't specified a osid so far then we should fill it
     # with the id from the node_types table now.
@@ -140,16 +141,25 @@ Node instproc updatedb {DB} {
 	}
     } else {
 	# Do not allow user to set os for virt nodes at this time.
-	if {$isvirt} {
+	if {$enforce_user_restrictions && $isvirt} {
 	    perror "You may not specify an OS for virtual nodes ($self)!"
 	    return
 	}
 	# Do not allow user to set os for host running virt nodes.
-	if {$virthost} {
+	if {$enforce_user_restrictions && $virthost} {
 	    perror "You may not specify an OS for hosting virtnodes ($self)!"
 	    return
 	}
     }
+    #
+    # For now, restrict local virtnodes to edge nodes, not routers.
+    #
+    if {$type == "pcvm" && $enforce_user_restrictions} {
+	if {[llength $portlist] > 1} {
+	    perror "Virtual node $self must be an edge node (lans/links = 1)"
+	    return
+	}
+    }
 
     # We need to generate the IP column from our iplist.
     set ipraw {}

tbsetup/ns2ir/parse.tcl.in

@@ -217,6 +217,8 @@ namespace eval GLOBALS {
     # is being parsed should go into a NSE simulation or not
     variable simulated 0
 
+    # Hidden variable to relax some restrictions for debugging.
+    variable enforce_user_restrictions 1
 }
 
 # Connect to the DB