Examples with Pair org.batfish.common.Pair used on opensource projects

Example 6 with Pair

use of org.batfish.common.Pair in project batfish by batfish.

the class Batfish method reducedReachability.

@Override
public AnswerElement reducedReachability(ReachabilitySettings reachabilitySettings) {
    Settings settings = getSettings();
    checkDifferentialDataPlaneQuestionDependencies();
    String tag = getDifferentialFlowTag();
    // load base configurations and generate base data plane
    pushBaseEnvironment();
    Map<String, Configuration> baseConfigurations = loadConfigurations();
    Synthesizer baseDataPlaneSynthesizer = synthesizeDataPlane();
    popEnvironment();
    // load diff configurations and generate diff data plane
    pushDeltaEnvironment();
    Map<String, Configuration> diffConfigurations = loadConfigurations();
    Synthesizer diffDataPlaneSynthesizer = synthesizeDataPlane();
    popEnvironment();
    Set<String> ingressNodes;
    try {
        ingressNodes = ImmutableSet.copyOf(Sets.intersection(reachabilitySettings.computeActiveIngressNodes(baseConfigurations), reachabilitySettings.computeActiveIngressNodes(diffConfigurations)));
    } catch (InvalidReachabilitySettingsException e) {
        return e.getInvalidSettingsAnswer();
    }
    pushDeltaEnvironment();
    SortedSet<String> blacklistNodes = getNodeBlacklist();
    Set<NodeInterfacePair> blacklistInterfaces = getInterfaceBlacklist();
    SortedSet<Edge> blacklistEdges = getEdgeBlacklist();
    popEnvironment();
    BlacklistDstIpQuerySynthesizer blacklistQuery = new BlacklistDstIpQuerySynthesizer(null, blacklistNodes, blacklistInterfaces, blacklistEdges, baseConfigurations);
    // compute composite program and flows
    List<Synthesizer> synthesizers = ImmutableList.of(baseDataPlaneSynthesizer, diffDataPlaneSynthesizer, baseDataPlaneSynthesizer);
    // generate base reachability and diff blackhole and blacklist queries
    List<CompositeNodJob> jobs = ingressNodes.stream().flatMap(node -> baseConfigurations.get(node).getVrfs().keySet().stream().map(vrf -> {
        Map<String, Set<String>> ingressNodeVrfs = ImmutableMap.of(node, ImmutableSet.of(vrf));
        StandardReachabilityQuerySynthesizer acceptQuery = StandardReachabilityQuerySynthesizer.builder().setActions(ImmutableSet.of(ForwardingAction.ACCEPT, ForwardingAction.NEIGHBOR_UNREACHABLE_OR_EXITS_NETWORK)).setHeaderSpace(reachabilitySettings.getHeaderSpace()).setIngressNodeVrfs(ingressNodeVrfs).setFinalNodes(ImmutableSet.of()).setTransitNodes(ImmutableSet.of()).setNonTransitNodes(ImmutableSet.of()).setSrcNatted(reachabilitySettings.getSrcNatted()).build();
        StandardReachabilityQuerySynthesizer notAcceptQuery = StandardReachabilityQuerySynthesizer.builder().setActions(ImmutableSet.of(ForwardingAction.ACCEPT, ForwardingAction.NEIGHBOR_UNREACHABLE_OR_EXITS_NETWORK)).setHeaderSpace(new HeaderSpace()).setIngressNodeVrfs(ingressNodeVrfs).setFinalNodes(ImmutableSet.of()).setTransitNodes(ImmutableSet.of()).setNonTransitNodes(ImmutableSet.of()).build();
        notAcceptQuery.setNegate(true);
        SortedSet<Pair<String, String>> nodes = ImmutableSortedSet.of(new Pair<>(node, vrf));
        List<QuerySynthesizer> queries = ImmutableList.of(acceptQuery, notAcceptQuery, blacklistQuery);
        return new CompositeNodJob(settings, synthesizers, queries, nodes, tag);
    })).collect(Collectors.toList());
    // TODO: maybe do something with nod answer element
    Set<Flow> flows = computeCompositeNodOutput(jobs, new NodAnswerElement());
    pushBaseEnvironment();
    getDataPlanePlugin().processFlows(flows, loadDataPlane());
    popEnvironment();
    pushDeltaEnvironment();
    getDataPlanePlugin().processFlows(flows, loadDataPlane());
    popEnvironment();
    AnswerElement answerElement = getHistory();
    return answerElement;
}

Example 7 with Pair

use of org.batfish.common.Pair in project batfish by batfish.

the class Batfish method singleReachability.

private AnswerElement singleReachability(ReachabilitySettings reachabilitySettings, ReachabilityQuerySynthesizer.Builder<?, ?> builder) {
    Settings settings = getSettings();
    String tag = getFlowTag(_testrigSettings);
    Set<ForwardingAction> actions = reachabilitySettings.getActions();
    boolean useCompression = reachabilitySettings.getUseCompression();
    // specialized compression
    /*
    CompressDataPlaneResult compressionResult =
        useCompression ? computeCompressedDataPlane(headerSpace) : null;
    Map<String, Configuration> configurations =
        useCompression ? compressionResult._compressedConfigs : loadConfigurations();
    DataPlane dataPlane = useCompression ? compressionResult._compressedDataPlane : loadDataPlane();
    */
    // general compression
    Snapshot snapshot = getSnapshot();
    Map<String, Configuration> configurations = useCompression ? loadCompressedConfigurations(snapshot) : loadConfigurations(snapshot);
    DataPlane dataPlane = loadDataPlane(useCompression);
    if (configurations == null) {
        throw new BatfishException("error loading configurations");
    }
    if (dataPlane == null) {
        throw new BatfishException("error loading data plane");
    }
    Set<String> activeIngressNodes;
    Set<String> activeFinalNodes;
    HeaderSpace headerSpace;
    Set<String> transitNodes;
    Set<String> nonTransitNodes;
    int maxChunkSize;
    try {
        activeIngressNodes = reachabilitySettings.computeActiveIngressNodes(configurations);
        activeFinalNodes = reachabilitySettings.computeActiveFinalNodes(configurations);
        headerSpace = reachabilitySettings.getHeaderSpace();
        transitNodes = reachabilitySettings.computeActiveTransitNodes(configurations);
        nonTransitNodes = reachabilitySettings.computeActiveNonTransitNodes(configurations);
        maxChunkSize = reachabilitySettings.getMaxChunkSize();
        reachabilitySettings.validateTransitNodes(configurations);
    } catch (InvalidReachabilitySettingsException e) {
        return e.getInvalidSettingsAnswer();
    }
    List<Pair<String, String>> originateNodeVrfs = activeIngressNodes.stream().flatMap(ingressNode -> configurations.get(ingressNode).getVrfs().keySet().stream().map(ingressVrf -> new Pair<>(ingressNode, ingressVrf))).collect(Collectors.toList());
    int chunkSize = Math.max(1, Math.min(maxChunkSize, originateNodeVrfs.size() / _settings.getAvailableThreads()));
    // partition originateNodeVrfs into chunks
    List<List<Pair<String, String>>> originateNodeVrfChunks = Lists.partition(originateNodeVrfs, chunkSize);
    Synthesizer dataPlaneSynthesizer = synthesizeDataPlane(configurations, dataPlane, loadForwardingAnalysis(configurations, dataPlane), headerSpace, reachabilitySettings.getSpecialize());
    // build query jobs
    List<NodJob> jobs = originateNodeVrfChunks.stream().map(ImmutableSortedSet::copyOf).map(nodeVrfs -> {
        SortedMap<String, Set<String>> vrfsByNode = new TreeMap<>();
        nodeVrfs.forEach(nodeVrf -> {
            String node = nodeVrf.getFirst();
            String vrf = nodeVrf.getSecond();
            vrfsByNode.computeIfAbsent(node, key -> new TreeSet<>());
            vrfsByNode.get(node).add(vrf);
        });
        ReachabilityQuerySynthesizer query = builder.setActions(actions).setHeaderSpace(headerSpace).setFinalNodes(activeFinalNodes).setIngressNodeVrfs(vrfsByNode).setTransitNodes(transitNodes).setNonTransitNodes(nonTransitNodes).setSrcNatted(reachabilitySettings.getSrcNatted()).build();
        return new NodJob(settings, dataPlaneSynthesizer, query, nodeVrfs, tag, reachabilitySettings.getSpecialize());
    }).collect(Collectors.toList());
    // run jobs and get resulting flows
    Set<Flow> flows = computeNodOutput(jobs);
    getDataPlanePlugin().processFlows(flows, loadDataPlane());
    AnswerElement answerElement = getHistory();
    return answerElement;
}

Example 8 with Pair

use of org.batfish.common.Pair in project batfish by batfish.

the class Batfish method initRemoteRipNeighbors.

@Override
public void initRemoteRipNeighbors(Map<String, Configuration> configurations, Map<Ip, Set<String>> ipOwners, Topology topology) {
    for (Entry<String, Configuration> e : configurations.entrySet()) {
        String hostname = e.getKey();
        Configuration c = e.getValue();
        for (Entry<String, Vrf> e2 : c.getVrfs().entrySet()) {
            Vrf vrf = e2.getValue();
            RipProcess proc = vrf.getRipProcess();
            if (proc != null) {
                proc.setRipNeighbors(new TreeMap<>());
                String vrfName = e2.getKey();
                for (String ifaceName : proc.getInterfaces()) {
                    Interface iface = vrf.getInterfaces().get("ifaceName");
                    SortedSet<Edge> ifaceEdges = topology.getInterfaceEdges().get(new NodeInterfacePair(hostname, ifaceName));
                    boolean hasNeighbor = false;
                    Ip localIp = iface.getAddress().getIp();
                    if (ifaceEdges != null) {
                        for (Edge edge : ifaceEdges) {
                            if (edge.getNode1().equals(hostname)) {
                                String remoteHostname = edge.getNode2();
                                String remoteIfaceName = edge.getInt2();
                                Configuration remoteNode = configurations.get(remoteHostname);
                                Interface remoteIface = remoteNode.getInterfaces().get(remoteIfaceName);
                                Vrf remoteVrf = remoteIface.getVrf();
                                String remoteVrfName = remoteVrf.getName();
                                RipProcess remoteProc = remoteVrf.getRipProcess();
                                if (remoteProc != null) {
                                    if (remoteProc.getRipNeighbors() == null) {
                                        remoteProc.setRipNeighbors(new TreeMap<>());
                                    }
                                    if (remoteProc.getInterfaces().contains(remoteIfaceName)) {
                                        Ip remoteIp = remoteIface.getAddress().getIp();
                                        Pair<Ip, Ip> localKey = new Pair<>(localIp, remoteIp);
                                        RipNeighbor neighbor = proc.getRipNeighbors().get(localKey);
                                        if (neighbor == null) {
                                            hasNeighbor = true;
                                            // initialize local neighbor
                                            neighbor = new RipNeighbor(localKey);
                                            neighbor.setVrf(vrfName);
                                            neighbor.setOwner(c);
                                            neighbor.setInterface(iface);
                                            proc.getRipNeighbors().put(localKey, neighbor);
                                            // initialize remote neighbor
                                            Pair<Ip, Ip> remoteKey = new Pair<>(remoteIp, localIp);
                                            RipNeighbor remoteNeighbor = new RipNeighbor(remoteKey);
                                            remoteNeighbor.setVrf(remoteVrfName);
                                            remoteNeighbor.setOwner(remoteNode);
                                            remoteNeighbor.setInterface(remoteIface);
                                            remoteProc.getRipNeighbors().put(remoteKey, remoteNeighbor);
                                            // link neighbors
                                            neighbor.setRemoteRipNeighbor(remoteNeighbor);
                                            remoteNeighbor.setRemoteRipNeighbor(neighbor);
                                        }
                                    }
                                }
                            }
                        }
                    }
                    if (!hasNeighbor) {
                        Pair<Ip, Ip> key = new Pair<>(localIp, Ip.ZERO);
                        RipNeighbor neighbor = new RipNeighbor(key);
                        neighbor.setVrf(vrfName);
                        neighbor.setOwner(c);
                        neighbor.setInterface(iface);
                        proc.getRipNeighbors().put(key, neighbor);
                    }
                }
            }
        }
    }
}

Example 9 with Pair

use of org.batfish.common.Pair in project batfish by batfish.

the class Encoder method initSlices.

/*
   * Initialize each encoding slice.
   * For iBGP, we also add reachability information for each pair of neighbors,
   * to determine if messages sent to/from a neighbor will arrive.
   */
private void initSlices(HeaderSpace h, Graph g) {
    if (g.getIbgpNeighbors().isEmpty() || !_modelIgp) {
        _slices.put(MAIN_SLICE_NAME, new EncoderSlice(this, h, g, ""));
    } else {
        _slices.put(MAIN_SLICE_NAME, new EncoderSlice(this, h, g, MAIN_SLICE_NAME));
    }
    if (_modelIgp) {
        SortedSet<Pair<String, Ip>> ibgpRouters = new TreeSet<>();
        for (Entry<GraphEdge, BgpNeighbor> entry : g.getIbgpNeighbors().entrySet()) {
            GraphEdge ge = entry.getKey();
            BgpNeighbor n = entry.getValue();
            String router = ge.getRouter();
            Ip ip = n.getLocalIp();
            Pair<String, Ip> pair = new Pair<>(router, ip);
            // Add one slice per (router, source ip) pair
            if (!ibgpRouters.contains(pair)) {
                ibgpRouters.add(pair);
                // Create a control plane slice only for this ip
                HeaderSpace hs = new HeaderSpace();
                // Make sure messages are sent to this destination IP
                SortedSet<IpWildcard> ips = new TreeSet<>();
                ips.add(new IpWildcard(n.getLocalIp()));
                hs.setDstIps(ips);
                // Make sure messages use TCP port 179
                SortedSet<SubRange> dstPorts = new TreeSet<>();
                dstPorts.add(new SubRange(179, 179));
                hs.setDstPorts(dstPorts);
                // Make sure messages use the TCP protocol
                SortedSet<IpProtocol> protocols = new TreeSet<>();
                protocols.add(IpProtocol.TCP);
                hs.setIpProtocols(protocols);
                // TODO: create domains once
                Graph gNew = new Graph(g.getBatfish(), null, g.getDomain(router));
                String sliceName = "SLICE-" + router + "_";
                EncoderSlice slice = new EncoderSlice(this, hs, gNew, sliceName);
                _slices.put(sliceName, slice);
                PropertyAdder pa = new PropertyAdder(slice);
                Map<String, BoolExpr> reachVars = pa.instrumentReachability(router);
                _sliceReachability.put(router, reachVars);
            }
        }
    }
}

Example 10 with Pair

use of org.batfish.common.Pair in project batfish by batfish.

the class TransferSSA method compute.

/*
   * Convert a list of statements into a Z3 boolean expression for the transfer function.
   */
private TransferResult<BoolExpr, BoolExpr> compute(List<Statement> statements, TransferParam<SymbolicRoute> p, TransferResult<BoolExpr, BoolExpr> result) {
    boolean doesReturn = false;
    for (Statement stmt : statements) {
        if (stmt instanceof StaticStatement) {
            StaticStatement ss = (StaticStatement) stmt;
            switch(ss.getType()) {
                case ExitAccept:
                    doesReturn = true;
                    p.debug("ExitAccept");
                    result = returnValue(p, result, true);
                    break;
                case ReturnTrue:
                    doesReturn = true;
                    p.debug("ReturnTrue");
                    result = returnValue(p, result, true);
                    break;
                case ExitReject:
                    doesReturn = true;
                    p.debug("ExitReject");
                    result = returnValue(p, result, false);
                    break;
                case ReturnFalse:
                    doesReturn = true;
                    p.debug("ReturnFalse");
                    result = returnValue(p, result, false);
                    break;
                case SetDefaultActionAccept:
                    p.debug("SetDefaulActionAccept");
                    p = p.setDefaultAccept(true);
                    break;
                case SetDefaultActionReject:
                    p.debug("SetDefaultActionReject");
                    p = p.setDefaultAccept(false);
                    break;
                case SetLocalDefaultActionAccept:
                    p.debug("SetLocalDefaultActionAccept");
                    p = p.setDefaultAcceptLocal(true);
                    break;
                case SetLocalDefaultActionReject:
                    p.debug("SetLocalDefaultActionReject");
                    p = p.setDefaultAcceptLocal(false);
                    break;
                case ReturnLocalDefaultAction:
                    p.debug("ReturnLocalDefaultAction");
                    // TODO: need to set local default action in an environment
                    if (p.getDefaultAcceptLocal()) {
                        result = returnValue(p, result, true);
                    } else {
                        result = returnValue(p, result, false);
                    }
                    break;
                case FallThrough:
                    p.debug("Fallthrough");
                    result = fallthrough(p, result);
                    break;
                case Return:
                    // TODO: assumming this happens at the end of the function, so it is ignored for now.
                    p.debug("Return");
                    break;
                case RemovePrivateAs:
                    p.debug("RemovePrivateAs");
                    System.out.println("Warning: use of unimplemented feature RemovePrivateAs");
                    break;
                default:
                    throw new BatfishException("TODO: computeTransferFunction: " + ss.getType());
            }
        } else if (stmt instanceof If) {
            p.debug("If");
            If i = (If) stmt;
            TransferResult<BoolExpr, BoolExpr> r = compute(i.getGuard(), p);
            result = result.addChangedVariables(r);
            BoolExpr guard = (BoolExpr) r.getReturnValue().simplify();
            String str = guard.toString();
            // If there are updates in the guard, add them to the parameter p before entering branches
            for (Pair<String, Expr> changed : r.getChangedVariables()) {
                p.debug("CHANGED: " + changed.getFirst());
                updateSingleValue(p, changed.getFirst(), changed.getSecond());
            }
            p.debug("guard: " + str);
            // If we know the branch ahead of time, then specialize
            switch(str) {
                case "true":
                    p.debug("True Branch");
                    result = compute(i.getTrueStatements(), p.indent(), result);
                    break;
                case "false":
                    p.debug("False Branch");
                    compute(i.getFalseStatements(), p.indent(), result);
                    break;
                default:
                    p.debug("True Branch");
                    // clear changed variables before proceeding
                    TransferParam<SymbolicRoute> p1 = p.indent().setData(p.getData().copy());
                    TransferParam<SymbolicRoute> p2 = p.indent().setData(p.getData().copy());
                    TransferResult<BoolExpr, BoolExpr> trueBranch = compute(i.getTrueStatements(), p1, initialResult());
                    p.debug("False Branch");
                    TransferResult<BoolExpr, BoolExpr> falseBranch = compute(i.getFalseStatements(), p2, initialResult());
                    p.debug("JOIN");
                    PList<Pair<String, Pair<Expr, Expr>>> pairs = trueBranch.mergeChangedVariables(falseBranch);
                    // Extract and deal with the return value first so that other
                    // variables have this reflected in their value
                    int idx = pairs.find(pair -> pair.getFirst().equals("RETURN"));
                    if (idx >= 0) {
                        Pair<String, Pair<Expr, Expr>> ret = pairs.get(idx);
                        pairs = pairs.minus(idx);
                        pairs = pairs.plus(pairs.size(), ret);
                    }
                    for (Pair<String, Pair<Expr, Expr>> pair : pairs) {
                        String s = pair.getFirst();
                        p.debug("CHANGED: " + s);
                        Pair<Expr, Expr> x = joinPoint(p, result, guard, pair);
                        result = result.addChangedVariable(s, x.getFirst());
                        if (s.equals("RETURN")) {
                            result = result.setReturnValue((BoolExpr) x.getFirst()).setReturnAssignedValue((BoolExpr) x.getSecond());
                        }
                        if (s.equals("FALLTHROUGH")) {
                            result = result.setFallthroughValue((BoolExpr) x.getFirst()).setReturnAssignedValue((BoolExpr) x.getSecond());
                        }
                    }
                    break;
            }
        } else if (stmt instanceof SetDefaultPolicy) {
            p.debug("SetDefaultPolicy");
            p = p.setDefaultPolicy((SetDefaultPolicy) stmt);
        } else if (stmt instanceof SetMetric) {
            p.debug("SetMetric");
            // TODO: what is the semantics for BGP? Is this MED?
            if (!_current.getProto().isBgp()) {
                SetMetric sm = (SetMetric) stmt;
                LongExpr ie = sm.getMetric();
                ArithExpr newValue = applyLongExprModification(p.getData().getMetric(), ie);
                newValue = _enc.mkIf(result.getReturnAssignedValue(), p.getData().getMetric(), newValue);
                ArithExpr x = createArithVariableWith(p, "METRIC", newValue);
                p.getData().setMetric(x);
                result = result.addChangedVariable("METRIC", x);
            }
        } else if (stmt instanceof SetOspfMetricType) {
            p.debug("SetOspfMetricType");
            SetOspfMetricType somt = (SetOspfMetricType) stmt;
            OspfMetricType mt = somt.getMetricType();
            SymbolicOspfType t;
            if (mt == OspfMetricType.E1) {
                t = new SymbolicOspfType(_enc, OspfType.E1);
            } else {
                t = new SymbolicOspfType(_enc, OspfType.E2);
            }
            BitVecExpr newValue = t.getBitVec();
            newValue = _enc.mkIf(result.getReturnAssignedValue(), p.getData().getOspfType().getBitVec(), newValue);
            BitVecExpr x = createBitVecVariableWith(p, "OSPF-TYPE", 2, newValue);
            p.getData().getOspfType().setBitVec(x);
            result = result.addChangedVariable("OSPF-TYPE", x);
        } else if (stmt instanceof SetLocalPreference) {
            p.debug("SetLocalPreference");
            SetLocalPreference slp = (SetLocalPreference) stmt;
            IntExpr ie = slp.getLocalPreference();
            ArithExpr newValue = applyIntExprModification(p.getData().getLocalPref(), ie);
            newValue = _enc.mkIf(result.getReturnAssignedValue(), p.getData().getLocalPref(), newValue);
            ArithExpr x = createArithVariableWith(p, "LOCAL-PREF", newValue);
            p.getData().setLocalPref(x);
            result = result.addChangedVariable("LOCAL-PREF", x);
        } else if (stmt instanceof AddCommunity) {
            p.debug("AddCommunity");
            AddCommunity ac = (AddCommunity) stmt;
            Set<CommunityVar> comms = _enc.getGraph().findAllCommunities(_conf, ac.getExpr());
            for (CommunityVar cvar : comms) {
                BoolExpr newValue = _enc.mkIf(result.getReturnAssignedValue(), p.getData().getCommunities().get(cvar), _enc.mkTrue());
                BoolExpr x = createBoolVariableWith(p, cvar.getValue(), newValue);
                p.getData().getCommunities().put(cvar, x);
                result = result.addChangedVariable(cvar.getValue(), x);
            }
        } else if (stmt instanceof SetCommunity) {
            p.debug("SetCommunity");
            SetCommunity sc = (SetCommunity) stmt;
            Set<CommunityVar> comms = _enc.getGraph().findAllCommunities(_conf, sc.getExpr());
            for (CommunityVar cvar : comms) {
                BoolExpr newValue = _enc.mkIf(result.getReturnAssignedValue(), p.getData().getCommunities().get(cvar), _enc.mkTrue());
                BoolExpr x = createBoolVariableWith(p, cvar.getValue(), newValue);
                p.getData().getCommunities().put(cvar, x);
                result = result.addChangedVariable(cvar.getValue(), x);
            }
        } else if (stmt instanceof DeleteCommunity) {
            p.debug("DeleteCommunity");
            DeleteCommunity ac = (DeleteCommunity) stmt;
            Set<CommunityVar> comms = _enc.getGraph().findAllCommunities(_conf, ac.getExpr());
            Set<CommunityVar> toDelete = new HashSet<>();
            // Find comms to delete
            for (CommunityVar cvar : comms) {
                if (cvar.getType() == Type.REGEX) {
                    toDelete.addAll(_enc.getCommunityDependencies().get(cvar));
                } else {
                    toDelete.add(cvar);
                }
            }
            // Delete each community
            for (CommunityVar cvar : toDelete) {
                BoolExpr newValue = _enc.mkIf(result.getReturnAssignedValue(), p.getData().getCommunities().get(cvar), _enc.mkFalse());
                BoolExpr x = createBoolVariableWith(p, cvar.getValue(), newValue);
                p.getData().getCommunities().put(cvar, x);
                result = result.addChangedVariable(cvar.getValue(), x);
            }
        } else if (stmt instanceof RetainCommunity) {
            p.debug("RetainCommunity");
        // no op
        } else if (stmt instanceof PrependAsPath) {
            p.debug("PrependAsPath");
            PrependAsPath pap = (PrependAsPath) stmt;
            Integer prependCost = prependLength(pap.getExpr());
            ArithExpr newValue = _enc.mkSum(p.getData().getMetric(), _enc.mkInt(prependCost));
            newValue = _enc.mkIf(result.getReturnAssignedValue(), p.getData().getMetric(), newValue);
            ArithExpr x = createArithVariableWith(p, "METRIC", newValue);
            p.getData().setMetric(x);
            result = result.addChangedVariable("METRIC", x);
        } else if (stmt instanceof SetOrigin) {
            p.debug("SetOrigin");
            System.out.println("Warning: use of unimplemented feature SetOrigin");
        } else if (stmt instanceof SetNextHop) {
            p.debug("SetNextHop");
            System.out.println("Warning: use of unimplemented feature SetNextHop");
        } else {
            String s = (_isExport ? "export" : "import");
            String msg = String.format("Unimplemented feature %s for %s transfer function on interface %s", stmt.toString(), s, _graphEdge.toString());
            throw new BatfishException(msg);
        }
    }
    // If this is the outermost call, then we relate the variables
    if (p.getInitialCall()) {
        p.debug("InitialCall finalizing");
        // Apply the default action
        if (!doesReturn) {
            p.debug("Applying default action: " + p.getDefaultAccept());
            if (p.getDefaultAccept()) {
                result = returnValue(p, result, true);
            } else {
                result = returnValue(p, result, false);
            }
        }
        BoolExpr related = relateVariables(p, result);
        BoolExpr retValue = _enc.mkIf(result.getReturnValue(), related, _enc.mkNot(_current.getPermitted()));
        result = result.setReturnValue(retValue);
    }
    return result;
}