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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.netobjs;
import java.util.ArrayList;
import java.util.List;
import com.microsoft.z3.BoolExpr;
import com.microsoft.z3.Context;
import com.microsoft.z3.DatatypeExpr;
import com.microsoft.z3.Expr;
import com.microsoft.z3.FuncDecl;
import com.microsoft.z3.IntExpr;
import com.microsoft.z3.Solver;
import com.microsoft.z3.Sort;
import mcnet.components.NetContext;
import mcnet.components.Network;
import mcnet.components.NetworkObject;
/**Cache Model
*
*/
public class PolitoCache extends NetworkObject{
List<BoolExpr> constraints;
Context ctx;
DatatypeExpr politoCache;
Network net;
NetContext nctx;
FuncDecl isInBlacklist;
public PolitoCache(Context ctx, Object[]... args) {
super(ctx, args);
}
@Override
protected void init(Context ctx, Object[]... args) {
this.ctx = ctx;
isEndHost=false;
constraints = new ArrayList<BoolExpr>();
z3Node = ((NetworkObject)args[0][0]).getZ3Node();
politoCache = z3Node;
net = (Network)args[0][1];
nctx = (NetContext)args[0][2];
//net.saneSend(this);
}
@Override
public DatatypeExpr getZ3Node() {
return politoCache;
}
@Override
protected void addConstraints(Solver solver) {
BoolExpr[] constr = new BoolExpr[constraints.size()];
solver.add(constraints.toArray(constr));
}
public void installCache (NetworkObject[] internalNodes){
Expr n_0 = ctx.mkConst("politoCache_"+politoCache+"_n_0", nctx.node);
Expr n_1 = ctx.mkConst("politoCache_"+politoCache+"_n_1", nctx.node);
Expr n_2 = ctx.mkConst("politoCache_"+politoCache+"_n_2", nctx.node);
Expr p_0 = ctx.mkConst("politoCache_"+politoCache+"_p_0", nctx.packet);
Expr p_1 = ctx.mkConst("politoCache_"+politoCache+"_p_1", nctx.packet);
Expr p_2 = ctx.mkConst("politoCache_"+politoCache+"_p_2", nctx.packet);
IntExpr t_0 = ctx.mkIntConst("politoCache_"+politoCache+"_t_0");
IntExpr t_1 = ctx.mkIntConst("politoCache_"+politoCache+"_t_1");
IntExpr t_2 = ctx.mkIntConst("politoCache_"+politoCache+"_t_2");
Expr a_0 = ctx.mkConst(politoCache+"politoCache_a_0", nctx.node);
IntExpr u_0 = ctx.mkIntConst("politoCache_"+politoCache+"_u_0");
FuncDecl isInternalNode = ctx.mkFuncDecl(politoCache+"_isInternalNode", nctx.node, ctx.mkBoolSort());
FuncDecl isInCache = ctx.mkFuncDecl(politoCache+"_isInCache", new Sort[]{ctx.mkIntSort(),ctx.mkIntSort()}, ctx.mkBoolSort());
assert(internalNodes.length!=0); //No internal nodes => Should never happen
//Modeling the behavior of the isInternalNode() and isInCache() functions
BoolExpr[] internalNodesConstraint = new BoolExpr[internalNodes.length];
for(int w=0;w<internalNodesConstraint.length;w++)
internalNodesConstraint[w]= (ctx.mkEq(a_0,internalNodes[w].getZ3Node()));
//Constraint1 if(isInternalNode(a_0) == or(listadeinodiinterni) ? True : false
constraints.add(
ctx.mkForall(new Expr[]{a_0},
ctx.mkIff((BoolExpr)isInternalNode.apply(a_0), ctx.mkOr(internalNodesConstraint)),1,null,null,null,null));
// constraints.add(ctx.mkForall(new Expr[]{a_0}, ctx.mkEq(isInternalNode.apply(a_0),ctx.mkOr(internalNodesConstraint)),1,null,null,null,null));
// constraints.add(ctx.mkForall(new Expr[]{u_0, t_0},
// ctx.mkITE(ctx.mkExists(new Expr[]{t_1, t_2, p_1, p_2, n_1, n_2},
// ctx.mkAnd(ctx.mkLt(t_1, t_2),
// ctx.mkLt(t_1, t_0),
// ctx.mkLt(t_2, t_0),
// (BoolExpr)nctx.recv.apply(n_1, politoCache, p_1, t_1),
// (BoolExpr)nctx.recv.apply(n_2, politoCache, p_2, t_2),
// ctx.mkEq(nctx.pf.get("proto").apply(p_1),ctx.mkInt(nctx.HTTP_REQUEST)),
// ctx.mkEq(nctx.pf.get("proto").apply(p_2),ctx.mkInt(nctx.HTTP_RESPONSE)),
// (BoolExpr)isInternalNode.apply(n_1),
// ctx.mkNot((BoolExpr)isInternalNode.apply(n_2)),
// ctx.mkEq(nctx.pf.get("url").apply(p_1),u_0),
// ctx.mkEq(nctx.pf.get("url").apply(p_2),u_0)),1,null,null,null,null),
// ctx.mkEq(isInCache.apply(u_0,t_0),ctx.mkBool(true)),ctx.mkEq(isInCache.apply(u_0,t_0),ctx.mkBool(false))),1,null,null,null,null));
//
//Constraint2 isInCache(u_0,t_0), exist t_1, t_2, p_1, p_2, n_1, n_2 :
// ( t_1< t_2 < t_0 && recv(n_1, politoCache, p_1, t_1) && recv(n_2, politoCache, p_2, t_2))) &&
// p_1.proto == HTTP_REQ && p_2.proto == HTTP_RESP &&
// isInternalNode(n_1) && !isInternalNode(n_2) &&
// p_1.url == u_0 && p_2.url == u_0 )
constraints.add(
ctx.mkForall(new Expr[]{u_0, t_0},
ctx.mkImplies((BoolExpr)isInCache.apply(u_0, t_0),
ctx.mkExists(new Expr[]{t_1,t_2,p_1,p_2,n_1, n_2},
ctx.mkAnd(
ctx.mkLt(t_1, t_2),
ctx.mkLt(t_1, t_0),
ctx.mkLt(t_2, t_0),
(BoolExpr)nctx.recv.apply(n_1, politoCache, p_1, t_1),
(BoolExpr)nctx.recv.apply(n_2, politoCache, p_2, t_2),
ctx.mkEq(nctx.pf.get("proto").apply(p_1), ctx.mkInt(nctx.HTTP_REQUEST)),
ctx.mkEq(nctx.pf.get("proto").apply(p_2), ctx.mkInt(nctx.HTTP_RESPONSE)),
(BoolExpr)isInternalNode.apply(n_1),
ctx.mkNot((BoolExpr)isInternalNode.apply(n_2)),
ctx.mkEq(nctx.pf.get("url").apply(p_1), u_0),
ctx.mkEq(nctx.pf.get("url").apply(p_2), u_0)),1,null,null,null,null)),1,null,null,null,null));
// //Always in cache
// constraints.add(ctx.mkForall(new Expr[]{u_0, t_0},ctx.mkEq(isInCache.apply(u_0,t_0),ctx.mkBool(true)),1,null,null,null,null));
//Constraint3 Modeling the behavior of the cache
// send(politoCache, n_0, p, t_0) && !isInternalNode(n_0) ->
// (exist t_1,n_1 :
// (t_1 < t_0 && recv(n_1, politoCache, p, t_1) &&
// p.proto == HTTP_REQ && !isInCache(p.url,t_0))
constraints.add(
ctx.mkForall(new Expr[]{n_0,p_0, t_0},
ctx.mkImplies(
ctx.mkAnd((BoolExpr)nctx.send.apply(politoCache,n_0,p_0,t_0),ctx.mkNot((BoolExpr)isInternalNode.apply(n_0))),
ctx.mkAnd(ctx.mkExists(new Expr[]{t_1, n_1},
ctx.mkAnd(
ctx.mkLt(t_1, t_0),
(BoolExpr)isInternalNode.apply(n_1),
(BoolExpr)nctx.recv.apply(n_1, politoCache, p_0, t_1)),1,null,null,null,null),
ctx.mkEq(nctx.pf.get("proto").apply(p_0), ctx.mkInt(nctx.HTTP_REQUEST)),
ctx.mkNot((BoolExpr)isInCache.apply(nctx.pf.get("url").apply(p_0), t_0)))),1,null,null,null,null));
//Constraint4 send(politoCache, n_0, p, t_0) && isInternalNode(n_0) ->
// (exist p_1,t_1 :
// (t_1 < t_0 && recv(n_0, politoCache, p_1, t_1) &&
// p_1.proto == HTTP_REQ && p.proto == HTTP_RESP &&
// p_1.url == p.url && p.src == p_1.dest && p.dest==p_1.src
// && isInCache(p.url,t_0))
constraints.add(
ctx.mkForall(new Expr[]{n_0,p_0, t_0},
ctx.mkImplies(
ctx.mkAnd((BoolExpr)nctx.send.apply(politoCache,n_0,p_0,t_0),(BoolExpr)isInternalNode.apply(n_0)),
ctx.mkAnd(ctx.mkExists(new Expr[]{p_1, t_1},
ctx.mkAnd(
ctx.mkLt(t_1, t_0),
(BoolExpr)nctx.recv.apply(n_0, politoCache, p_1, t_1),
ctx.mkEq(nctx.pf.get("proto").apply(p_1), ctx.mkInt(nctx.HTTP_REQUEST)),
ctx.mkEq(nctx.pf.get("url").apply(p_1), nctx.pf.get("url").apply(p_0))),1,null,null,null,null),
ctx.mkEq(nctx.pf.get("proto").apply(p_0), ctx.mkInt(nctx.HTTP_RESPONSE)),
ctx.mkEq(nctx.pf.get("src").apply(p_0), nctx.pf.get("dest").apply(p_1)),
ctx.mkEq(nctx.pf.get("dest").apply(p_0), nctx.pf.get("src").apply(p_1)),
(BoolExpr)isInCache.apply(nctx.pf.get("url").apply(p_0), t_0))),1,null,null,null,null));
}
}
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