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/*******************************************************************************
* Copyright (c) 2017 Politecnico di Torino and others.
*
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Apache License, Version 2.0
* which accompanies this distribution, and is available at
* http://www.apache.org/licenses/LICENSE-2.0
*******************************************************************************/
package mcnet.components;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import com.microsoft.z3.BoolExpr;
import com.microsoft.z3.Context;
import com.microsoft.z3.DatatypeExpr;
import com.microsoft.z3.Expr;
import com.microsoft.z3.IntExpr;
import com.microsoft.z3.Solver;
import com.microsoft.z3.Z3Exception;
/**Model for a network, encompasses routing and wiring
*
*/
public class Network extends Core{
Context ctx;
NetContext nctx;
List<BoolExpr> constraints;
List<NetworkObject> elements;
public Network(Context ctx,Object[]... args) {
super(ctx, args);
}
@Override
protected void init(Context ctx, Object[]... args) {
this.ctx = ctx;
this.nctx = (NetContext) args[0][0];
constraints = new ArrayList<BoolExpr>();
elements = new ArrayList<NetworkObject>();
}
/**Composes the network linking the configured network objects
*
* @param elements
*/
public void attach (NetworkObject ... elements){
for(NetworkObject el : elements)
this.elements.add(el);
}
@Override
protected void addConstraints(Solver solver) {
try {
BoolExpr[] constr = new BoolExpr[constraints.size()];
solver.add(constraints.toArray(constr));
} catch (Z3Exception e) {
e.printStackTrace();
}
}
/**
* Specify host to address mapping.
* Handles the case in which we have more than one address for a node
* @param addrmap
*/
public void setAddressMappings(ArrayList<Tuple<NetworkObject,ArrayList<DatatypeExpr>>> addrmap){
// Set address mapping for nodes.
for (Tuple<NetworkObject,ArrayList<DatatypeExpr>> entry : addrmap) {
NetworkObject node=entry._1;
List<DatatypeExpr> addr=entry._2;
Expr a_0 = ctx.mkConst(node+"_address_mapping_a_0",nctx.address);
ArrayList<BoolExpr> or_clause = new ArrayList<BoolExpr>();
// Constraint 1 addrToNode(foreach ad in addr) = node
for (DatatypeExpr ad : addr){
constraints.add(ctx.mkEq(nctx.addrToNode.apply(ad), node.getZ3Node()));
or_clause.add(ctx.mkEq(a_0,ad));
}
BoolExpr[] orClause = new BoolExpr[or_clause.size()];
// Constraint 2 nodeHasAddr(node, a_0) == Or(foreach ad in addr (a_0 == ad))
// Note we need the iff here to make sure that we set nodeHasAddr to false
// for other addresses.
constraints.add(ctx.mkForall(new Expr[]{a_0},
ctx.mkEq(ctx.mkOr(or_clause.toArray(orClause)), nctx.nodeHasAddr.apply(node.getZ3Node(), a_0)),1,null,null,null,null));
}
}
/**
* Don't forward packets addressed to node
* @param node
*/
public void saneSend(NetworkObject node){
Expr n_0 = ctx.mkConst(node+"_saneSend_n_0", nctx.node);
Expr p_0 = ctx.mkConst(node+"_saneSend_p_0", nctx.packet);
IntExpr t_0 = ctx.mkIntConst(node+"_saneSend_t_0");
// Constant: node
//Constraint send(node, n_0, p, t_0) -> !nodeHasAddr(node, p.dest)
constraints.add(
ctx.mkForall(new Expr[]{n_0, p_0, t_0},
ctx.mkImplies((BoolExpr)nctx.send.apply(node.getZ3Node(),n_0, p_0, t_0),
ctx.mkNot((BoolExpr)nctx.nodeHasAddr.apply( node.getZ3Node(),
nctx.pf.get("dest").apply(p_0)))),1,null,null,null,null));
}
/**
* Node sends all traffic through gateway
* @param node
* @param gateway
*/
public void setGateway (NetworkObject node, NetworkObject gateway){
// SetGateway(self, node, gateway): All packets from node are sent through gateway
Expr n_0 = ctx.mkConst(node+"_gateway_n_0", nctx.node);
Expr p_0 = ctx.mkConst(node+"_gateway_p_0", nctx.packet);
IntExpr t_0 = ctx.mkIntConst(node+"_gateway_t_0");
//Constraint send(node, n_0, p_0, t_0) -> n_0 = gateway
constraints.add(
ctx.mkForall(new Expr[]{n_0, p_0, t_0},
ctx.mkImplies(
(BoolExpr)nctx.send.apply(node.getZ3Node(), n_0, p_0, t_0),
ctx.mkEq(n_0,gateway.getZ3Node())),1,null,null,null,null));
// constraints.add(ctx.mkForall(new Expr[]{n_0, p_0, t_0},
// ctx.mkImplies((BoolExpr)nctx.recv.apply(n_0, node.getZ3Node(), p_0, t_0),
// ctx.mkEq(n_0,gateway.getZ3Node())),1,null,null,null,null));
}
/**
* Assigns a specific routing table to a network object. Routing entries in the form: address -> node
* @param node
* @param routing_table
*/
public void routingTable (NetworkObject node,ArrayList<Tuple<DatatypeExpr,NetworkObject>> routing_table){
compositionPolicy(node,routing_table);
}
/**
* Composition policies steer packets between middleboxes.
* @param node
* @param policy
*/
public void compositionPolicy (NetworkObject node,ArrayList<Tuple<DatatypeExpr,NetworkObject>> policy){
//Policy is of the form predicate -> node
Expr p_0 = ctx.mkConst(node+"_composition_p_0", nctx.packet);
Expr n_0 = ctx.mkConst(node+"_composition_n_0", nctx.node);
Expr t_0 = ctx.mkIntConst(node+"_composition_t_0");
HashMap<String,ArrayList<BoolExpr>> collected = new HashMap<String,ArrayList<BoolExpr>>();
HashMap<String,NetworkObject> node_dict = new HashMap<String,NetworkObject>();
BoolExpr predicates;
for(int y=0;y<policy.size();y++){
Tuple<DatatypeExpr,NetworkObject> tp = policy.get(y);
if(collected.containsKey(""+tp._2)) collected.get(""+tp._2).add(nctx.destAddrPredicate(p_0,tp._1));
else{
ArrayList<BoolExpr> alb = new ArrayList<BoolExpr>();
alb.add(nctx.destAddrPredicate(p_0,tp._1));
collected.put(""+tp._2,alb);
}
node_dict.put(""+tp._2, tp._2);
}
//Constraint foreach rtAddr,rtNode in rt( send(node, n_0, p_0, t_0) &&
// Or(foreach rtAddr in rt destAddrPredicate(p_0,rtAddr)) -> n_0 == rtNode )
for (Map.Entry<String,ArrayList<BoolExpr>> entry : collected.entrySet()) {
BoolExpr[] pred = new BoolExpr[entry.getValue().size()];
predicates = ctx.mkOr(entry.getValue().toArray(pred));
constraints.add(ctx.mkForall(new Expr[]{n_0, p_0, t_0},
ctx.mkImplies(ctx.mkAnd((BoolExpr)nctx.send.apply(node.getZ3Node(), n_0, p_0, t_0), predicates),
ctx.mkEq(n_0, node_dict.get(entry.getKey()).getZ3Node())),1,null,null,null,null));
}
}
/**
* Routing entries are in the form: address -> node. Also allows packet to be sent to another box for further processing
* @param node
* @param routing_table
* @param shunt_node
*/
public void routingTableShunt (NetworkObject node,ArrayList<Tuple<DatatypeExpr,NetworkObject>> routing_table,NetworkObject shunt_node){
compositionPolicyShunt(node,routing_table,shunt_node);
}
/**
* Composition policies steer packets between middleboxes.Policy is in the form: predicate -> node
* @param node
* @param routing_table
* @param shunt_node
*/
public void compositionPolicyShunt (NetworkObject node,ArrayList<Tuple<DatatypeExpr,NetworkObject>> routing_table,NetworkObject shunt_node){
Expr p_0 = ctx.mkConst(node+"_composition_p_0", nctx.packet);
Expr n_0 = ctx.mkConst(node+"_composition_n_0", nctx.node);
Expr t_0 = ctx.mkIntConst(node+"_composition_t_0");
HashMap<String,ArrayList<BoolExpr>> collected = new HashMap<String,ArrayList<BoolExpr>>();
HashMap<String,NetworkObject> node_dict = new HashMap<String,NetworkObject>();
BoolExpr predicates;
for(int y=0;y<routing_table.size();y++){
Tuple<DatatypeExpr,NetworkObject> tp = routing_table.get(y);
if(collected.containsKey(""+tp._2)) collected.get(""+tp._2).add(nctx.destAddrPredicate(p_0,tp._1));
else{
ArrayList<BoolExpr> alb = new ArrayList<BoolExpr>();
alb.add(nctx.destAddrPredicate(p_0,tp._1));
collected.put(""+tp._2,alb);
}
node_dict.put(""+tp._2, tp._2);
}
//Constraint foreach rtAddr,rtNode in rt( send(node, n_0, p_0, t_0) &&
// Or(foreach rtAddr in rt destAddrPredicate(p_0,rtAddr)) -> n_0 == rtNode )
for (Map.Entry<String,ArrayList<BoolExpr>> entry : collected.entrySet()) {
BoolExpr[] pred = new BoolExpr[entry.getValue().size()];
predicates = ctx.mkOr(entry.getValue().toArray(pred));
constraints.add(ctx.mkForall(new Expr[]{n_0, p_0, t_0},
ctx.mkImplies(ctx.mkAnd((BoolExpr)nctx.send.apply(node.getZ3Node(), n_0, p_0, t_0), predicates),
ctx.mkOr(ctx.mkEq(n_0, node_dict.get(entry.getKey()).getZ3Node()),ctx.mkEq(n_0, shunt_node.getZ3Node()))),1,null,null,null,null));
}
}
// public void SimpleIsolation (NetworkObject node, ArrayList<DatatypeExpr> addresses){
// Expr p = ctx.mkConst(node+"_s_p", nctx.packet);
// Expr n = ctx.mkConst(node+"_s_n", nctx.node);
// IntExpr t = ctx.mkInt(node+"_s_t");
//
// BoolExpr[] a_pred= new BoolExpr[addresses.size()];
// for(int y=0;y<addresses.size();y++){
// DatatypeExpr de = addresses.get(y);
// a_pred[y] = ctx.mkOr(ctx.mkEq(nctx.pf.get("src").apply(p), de),ctx.mkEq(nctx.pf.get("dest").apply(p), de));
// }
//
// constraints.add(
// ctx.mkForall(new Expr[]{p, n, t},
// ctx.mkImplies((BoolExpr)nctx.recv.apply(n, node.getZ3Node(), p, t),
// ctx.mkOr(a_pred)),1,null,null,null,null));
// constraints.add(
// ctx.mkForall(new Expr[]{p, n, t},
// ctx.mkImplies((BoolExpr)nctx.send.apply(node.getZ3Node(), n, p, t),
// ctx.mkOr(a_pred)),1,null,null,null,null));
// }
/**
* Set isolation constraints on a node.
* Doesn't need to be set but useful when interfering policies are in play.
* @param node
* @param adjacencies
*
*/
public void SetIsolationConstraint ( NetworkObject node, ArrayList<NetworkObject> adjacencies){
Expr n_0 = ctx.mkConst(node+"_isolation_n_0", nctx.node);
Expr p_0 = ctx.mkConst(node+"_isolation_p_0", nctx.packet);
IntExpr t_0 = ctx.mkInt(node+"_isolation_t_0");
BoolExpr[] adj = new BoolExpr[adjacencies.size()];
for(int y=0;y<adjacencies.size();y++){
NetworkObject no = adjacencies.get(y);
adj[y] = ctx.mkEq(n_0,no.getZ3Node());
}
BoolExpr clause = ctx.mkOr(adj);
constraints.add(ctx.mkForall(new Expr[]{n_0, p_0, t_0},
ctx.mkImplies((BoolExpr)nctx.send.apply(node.getZ3Node(), n_0, p_0, t_0),
clause),1,null,null,null,null));
constraints.add(ctx.mkForall(new Expr[]{n_0, p_0, t_0},
ctx.mkImplies((BoolExpr)nctx.recv.apply(n_0, node.getZ3Node(), p_0, t_0),
clause),1,null,null,null,null));
}
/**
* Return all currently attached endhosts
* @return NetworkObject
*/
public List<String> EndHosts(){
List<String> att_nos = new ArrayList<String>();
for(NetworkObject el :elements){
if(el.isEndHost){
System.out.println("el: "+el);
att_nos.add(el.getZ3Node().toString());
}
}
return att_nos;
}
}
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