use of org.batfish.symbolic.GraphEdge in project batfish by batfish.
the class CounterExample method buildFailedLinks.
SortedSet<Edge> buildFailedLinks(Encoder enc) {
Set<GraphEdge> failed = new HashSet<>();
Graph g = enc.getMainSlice().getGraph();
for (List<GraphEdge> edges : g.getEdgeMap().values()) {
for (GraphEdge ge : edges) {
ArithExpr e = enc.getSymbolicFailures().getFailedVariable(ge);
assert e != null;
if (intVal(e) != 0) {
// Don't add both directions?
GraphEdge other = g.getOtherEnd().get(ge);
if (other == null || !failed.contains(other)) {
failed.add(ge);
}
}
}
}
// Convert to Batfish Edge type
SortedSet<Edge> failedEdges = new TreeSet<>();
for (GraphEdge ge : failed) {
failedEdges.add(fromGraphEdge(ge));
}
return failedEdges;
}
use of org.batfish.symbolic.GraphEdge in project batfish by batfish.
the class CounterExample method buildEnvRoutingTable.
SortedSet<BgpAdvertisement> buildEnvRoutingTable(Encoder enc) {
SortedSet<BgpAdvertisement> routes = new TreeSet<>();
EncoderSlice slice = enc.getMainSlice();
LogicalGraph lg = slice.getLogicalGraph();
for (Entry<LogicalEdge, SymbolicRoute> entry : lg.getEnvironmentVars().entrySet()) {
LogicalEdge lge = entry.getKey();
SymbolicRoute record = entry.getValue();
// If there is an external advertisement
if (boolVal(record.getPermitted())) {
// If we actually use it
GraphEdge ge = lge.getEdge();
String router = ge.getRouter();
SymbolicDecisions decisions = slice.getSymbolicDecisions();
BoolExpr ctrFwd = decisions.getControlForwarding().get(router, ge);
assert ctrFwd != null;
if (boolVal(ctrFwd)) {
SymbolicRoute r = decisions.getBestNeighbor().get(router);
SymbolicPacket pkt = slice.getSymbolicPacket();
Flow f = buildFlow(pkt, router);
Prefix pfx = buildPrefix(r, f);
int pathLength = intVal(r.getMetric());
// Create dummy information
BgpNeighbor n = slice.getGraph().getEbgpNeighbors().get(lge.getEdge());
String srcNode = "as" + n.getRemoteAs();
Ip zeroIp = new Ip(0);
Ip dstIp = n.getLocalIp();
// Recover AS path
List<SortedSet<Integer>> asSets = new ArrayList<>();
for (int i = 0; i < pathLength; i++) {
SortedSet<Integer> asSet = new TreeSet<>();
asSet.add(-1);
asSets.add(asSet);
}
AsPath path = new AsPath(asSets);
// Recover communities
SortedSet<Long> communities = new TreeSet<>();
for (Entry<CommunityVar, BoolExpr> entry2 : r.getCommunities().entrySet()) {
CommunityVar cvar = entry2.getKey();
BoolExpr expr = entry2.getValue();
if (cvar.getType() == Type.EXACT && boolVal(expr)) {
communities.add(cvar.asLong());
}
}
BgpAdvertisement adv = new BgpAdvertisement(BgpAdvertisementType.EBGP_RECEIVED, pfx, zeroIp, srcNode, "default", zeroIp, router, "default", dstIp, RoutingProtocol.BGP, OriginType.EGP, 100, 80, zeroIp, path, communities, new TreeSet<>(), 0);
routes.add(adv);
}
}
}
return routes;
}
use of org.batfish.symbolic.GraphEdge in project batfish by batfish.
the class PropertyChecker method checkDeterminism.
/*
* Check if there exist multiple stable solutions to the network.
* If so, reports the forwarding differences between the two cases.
*/
public AnswerElement checkDeterminism(HeaderQuestion q) {
Graph graph = new Graph(_batfish);
Encoder enc1 = new Encoder(_settings, graph, q);
Encoder enc2 = new Encoder(enc1, graph, q);
enc1.computeEncoding();
enc2.computeEncoding();
addEnvironmentConstraints(enc1, q.getBaseEnvironmentType());
BoolExpr relatedFailures = relateFailures(enc1, enc2);
BoolExpr relatedEnvs = relateEnvironments(enc1, enc2);
BoolExpr relatedPkts = relatePackets(enc1, enc2);
BoolExpr related = enc1.mkAnd(relatedFailures, relatedEnvs, relatedPkts);
BoolExpr required = enc1.mkTrue();
for (GraphEdge ge : graph.getAllRealEdges()) {
SymbolicDecisions d1 = enc1.getMainSlice().getSymbolicDecisions();
SymbolicDecisions d2 = enc2.getMainSlice().getSymbolicDecisions();
BoolExpr dataFwd1 = d1.getDataForwarding().get(ge.getRouter(), ge);
BoolExpr dataFwd2 = d2.getDataForwarding().get(ge.getRouter(), ge);
assert dataFwd1 != null;
assert dataFwd2 != null;
required = enc1.mkAnd(required, enc1.mkEq(dataFwd1, dataFwd2));
}
enc1.add(related);
enc1.add(enc1.mkNot(required));
Tuple<VerificationResult, Model> tup = enc1.verify();
VerificationResult res = tup.getFirst();
Model model = tup.getSecond();
SortedSet<String> case1 = null;
SortedSet<String> case2 = null;
Flow flow = null;
CounterExample ce = new CounterExample(model);
if (!res.isVerified()) {
case1 = new TreeSet<>();
case2 = new TreeSet<>();
flow = ce.buildFlow(enc1.getMainSlice().getSymbolicPacket(), "(none)");
for (GraphEdge ge : graph.getAllRealEdges()) {
SymbolicDecisions d1 = enc1.getMainSlice().getSymbolicDecisions();
SymbolicDecisions d2 = enc2.getMainSlice().getSymbolicDecisions();
BoolExpr dataFwd1 = d1.getDataForwarding().get(ge.getRouter(), ge);
BoolExpr dataFwd2 = d2.getDataForwarding().get(ge.getRouter(), ge);
assert dataFwd1 != null;
assert dataFwd2 != null;
boolean b1 = ce.boolVal(dataFwd1);
boolean b2 = ce.boolVal(dataFwd2);
if (b1 != b2) {
if (b1) {
String route = ce.buildRoute(enc1.getMainSlice(), ge);
String msg = ge + " -- " + route;
case1.add(msg);
}
if (b2) {
String route = ce.buildRoute(enc2.getMainSlice(), ge);
String msg = ge + " -- " + route;
case2.add(msg);
}
}
}
}
// Ensure canonical order
boolean less = (case1 == null || (case1.first().compareTo(case2.first()) < 0));
if (less) {
return new SmtDeterminismAnswerElement(flow, case1, case2);
} else {
return new SmtDeterminismAnswerElement(flow, case2, case1);
}
}
use of org.batfish.symbolic.GraphEdge 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);
}
}
}
}
use of org.batfish.symbolic.GraphEdge in project batfish by batfish.
the class Encoder method initFailedLinkVariables.
/*
* Initialize symbolic variables to represent link failures.
*/
private void initFailedLinkVariables() {
for (List<GraphEdge> edges : _graph.getEdgeMap().values()) {
for (GraphEdge ge : edges) {
if (ge.getPeer() == null) {
Interface i = ge.getStart();
String name = getId() + "_FAILED-EDGE_" + ge.getRouter() + "_" + i.getName();
ArithExpr var = getCtx().mkIntConst(name);
_symbolicFailures.getFailedEdgeLinks().put(ge, var);
_allVariables.put(var.toString(), var);
}
}
}
for (Entry<String, Set<String>> entry : _graph.getNeighbors().entrySet()) {
String router = entry.getKey();
Set<String> peers = entry.getValue();
for (String peer : peers) {
// sort names for unique
String pair = (router.compareTo(peer) < 0 ? router + "_" + peer : peer + "_" + router);
String name = getId() + "_FAILED-EDGE_" + pair;
ArithExpr var = _ctx.mkIntConst(name);
_symbolicFailures.getFailedInternalLinks().put(router, peer, var);
_allVariables.put(var.toString(), var);
}
}
}
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