Examples with SetResponse org.xbill.DNS.SetResponse used on opensource projects

Example 1 with SetResponse

use of org.xbill.DNS.SetResponse in project GNS by MobilityFirst.

the class NameResolution method lookupDnsCache.

/**
   * Look up the local dns server cache.
   * Returns a {@link Message}.
   *
   * @param query
   * @param dnsCache
   * @return a Message
   */
public static Message lookupDnsCache(Message query, Cache dnsCache) {
    // check for queries we can't handle
    int type = query.getQuestion().getType();
    // Was the query legitimate or implemented?
    if (!Type.isRR(type) && type != Type.ANY) {
        return errorMessage(query, Rcode.NOTIMP);
    }
    // extract the domain (guid) and field from the query
    final Name requestedName = query.getQuestion().getName();
    final byte[] rawName = requestedName.toWire();
    final String lookupName = querytoStringForGNS(rawName);
    NameResolution.getLogger().log(Level.FINER, "Looking up name in cache: {0}", lookupName);
    SetResponse lookupresult = dnsCache.lookupRecords(requestedName, Type.ANY, Credibility.NORMAL);
    if (lookupresult.isSuccessful()) {
        Message response = new Message(query.getHeader().getID());
        response.getHeader().setFlag(Flags.QR);
        if (query.getHeader().getFlag(Flags.RD)) {
            response.getHeader().setFlag(Flags.RA);
        }
        response.addRecord(query.getQuestion(), Section.QUESTION);
        response.getHeader().setFlag(Flags.AA);
        ArrayList<Name> cnameNames = new ArrayList<>();
        // Write the response
        for (RRset rrset : lookupresult.answers()) {
            NameResolution.getLogger().log(Level.FINE, "{0}\n", rrset.toString());
            Iterator<?> rrItr = rrset.rrs();
            while (rrItr.hasNext()) {
                Record curRecord = (Record) rrItr.next();
                response.addRecord(curRecord, Section.ANSWER);
                if (curRecord.getType() == Type.CNAME) {
                    cnameNames.add(((CNAMERecord) curRecord).getAlias());
                }
            }
        }
        if (cnameNames.isEmpty()) {
            return response;
        }
        // For all CNAMES in the response, add their A records
        for (Name cname : cnameNames) {
            NameResolution.getLogger().log(Level.FINE, "Looking up CNAME in cache: {0}", cname.toString());
            SetResponse lookUpResult = dnsCache.lookupRecords(cname, Type.ANY, Credibility.NORMAL);
            if (lookUpResult.isSuccessful()) {
                for (RRset rrset : lookUpResult.answers()) {
                    NameResolution.getLogger().log(Level.FINE, "{0}\n", rrset.toString());
                    Iterator<?> rrItr = rrset.rrs();
                    while (rrItr.hasNext()) {
                        Record curRecord = (Record) rrItr.next();
                        response.addRecord(curRecord, Section.ANSWER);
                    }
                }
            }
        }
        return response;
    } else {
        return errorMessage(query, Rcode.NOTIMP);
    }
}

Example 2 with SetResponse

use of org.xbill.DNS.SetResponse in project GNS by MobilityFirst.

the class LookupWorker method generateReply.

/**
   * Queries DNS and/or GNS servers for DNS records.
   *
   * Note: a null return value means that the caller doesn't need to do
   * anything. Currently this only happens if this is an AXFR request over TCP.
   */
private Message generateReply(Message query) {
    long startTime = System.currentTimeMillis();
    NameResolution.getLogger().log(Level.FINE, "Incoming request:\n {0}", query.toString());
    // If it's not a query we just ignore it.
    if (query.getHeader().getFlag(Flags.QR)) {
        return null;
    }
    long checkStart = System.currentTimeMillis();
    // Check for wierd queries we can't handle.
    Message errorMessage;
    if ((errorMessage = NameResolution.checkForErroneousQueries(query)) != null) {
        return errorMessage;
    }
    DelayProfiler.updateDelay("checkForErroneousQueries", checkStart);
    // If we're not consulting the DNS server as well just send the query to GNS.
    if (dnsServer == null) {
        Message result = NameResolution.lookupGnsServer(incomingPacket.getAddress(), query, handler);
        DelayProfiler.updateDelay("generateReply", startTime);
        return result;
    }
    // Otherwise as a first step before performing GNS/DNS lookup we check our own local cache.
    if (dnsCache != null) {
        Message tempQuery = (Message) query.clone();
        Message result = NameResolution.lookupDnsCache(tempQuery, dnsCache);
        if (result.getHeader().getRcode() == Rcode.NOERROR) {
            NameResolution.getLogger().log(Level.FINE, "Responding the request from cache {0}", NameResolution.queryAndResponseToString(query, result));
            return result;
        }
    }
    // Create a clone of the query for duplicating the request to GNS and DNS
    Message dnsQuery = (Message) query.clone();
    List<LookupTask> tasks;
    if (gnsServer == null) {
        // We make two tasks to check the DNS and GNS in parallel
        tasks = Arrays.asList(// Create GNS lookup task
        new LookupTask(query, handler), // Create DNS lookup task
        new LookupTask(dnsQuery, dnsServer, handler));
    } else {
        tasks = Arrays.asList(// Create GNS lookup task
        new LookupTask(query, gnsServer, true, /* isGNS */
        handler), // Create DNS lookup task
        new LookupTask(dnsQuery, dnsServer, false, /* isGNS */
        handler));
    }
    // A little bit of overkill for two tasks, but it's really not that much longer (if any) than
    // the altenative. Plus it's cool and trendy to use futures.
    ExecutorService executor = Executors.newFixedThreadPool(2);
    ExecutorCompletionService<Message> completionService = new ExecutorCompletionService<>(executor);
    List<Future<Message>> futures = new ArrayList<>(2);
    for (Callable<Message> task : tasks) {
        futures.add(completionService.submit(task));
    }
    Message successResponse = null;
    Message errorResponse = null;
    // loop throught the tasks getting results as they complete
    for (LookupTask task : tasks) {
        // this is just doing things twice btw
        try {
            Message result = completionService.take().get();
            if (result.getHeader().getRcode() == Rcode.NOERROR) {
                successResponse = result;
                break;
            } else {
                // squirrel this away for later in case we get no successes
                errorResponse = result;
            }
        } catch (ExecutionException e) {
            NameResolution.getLogger().log(Level.WARNING, "Problem handling lookup task: {0}", e);
        } catch (InterruptedException e) {
            NameResolution.getLogger().log(Level.WARNING, "Lookup task interrupted: {0}", e);
        }
    }
    // Shutdown the executor threadpool
    executor.shutdown();
    if (successResponse != null) {
        // Cache the successful response
        try {
            SetResponse addMsgResponse = dnsCache.addMessage(successResponse);
            if (!addMsgResponse.isSuccessful()) {
                RRset[] answers = successResponse.getSectionRRsets(Section.ANSWER);
                boolean isAuth = successResponse.getHeader().getFlag(Flags.AA);
                int qClass = successResponse.getQuestion().getDClass();
                for (int i = 0; i < answers.length; i++) {
                    if (answers[i].getDClass() != qClass) {
                        continue;
                    }
                    int cred = getCred(Section.ANSWER, isAuth);
                    dnsCache.addRRset(answers[i], cred);
                    NameResolution.getLogger().log(Level.FINE, "Records added to cache {0}", answers[i].toString());
                }
            }
        } catch (NullPointerException e) {
            NameResolution.getLogger().log(Level.WARNING, "Failed to add a dns response to cache{0}", e);
        }
        return successResponse;
    } else if (errorResponse != null) {
        // currently this is returning the second error response... do we care?
        return errorResponse;
    } else {
        return NameResolution.errorMessage(query, Rcode.NXDOMAIN);
    }
}

Example 3 with SetResponse

use of org.xbill.DNS.SetResponse in project opennms by OpenNMS.

the class DNSServer method addCacheNS.

private final void addCacheNS(final Message response, final Cache cache, final Name name) {
    final SetResponse sr = cache.lookupRecords(name, Type.NS, Credibility.HINT);
    if (!sr.isDelegation())
        return;
    final RRset nsRecords = sr.getNS();
    @SuppressWarnings("unchecked") final Iterator<Record> it = nsRecords.rrs();
    while (it.hasNext()) {
        final Record r = it.next();
        response.addRecord(r, Section.AUTHORITY);
    }
}

Example 4 with SetResponse

use of org.xbill.DNS.SetResponse in project opennms by OpenNMS.

the class DNSServer method addAnswer.

byte addAnswer(final Message response, final Name name, int type, int dclass, int iterations, int flags) {
    SetResponse sr;
    byte rcode = Rcode.NOERROR;
    if (iterations > 6)
        return Rcode.NOERROR;
    if (type == Type.SIG || type == Type.RRSIG) {
        type = Type.ANY;
        flags |= FLAG_SIGONLY;
    }
    final Zone zone = findBestZone(name);
    if (zone != null)
        sr = zone.findRecords(name, type);
    else {
        sr = getCache(dclass).lookupRecords(name, type, Credibility.NORMAL);
    }
    if (sr.isUnknown()) {
        addCacheNS(response, getCache(dclass), name);
    }
    if (sr.isNXDOMAIN()) {
        response.getHeader().setRcode(Rcode.NXDOMAIN);
        if (zone != null) {
            addSOA(response, zone);
            if (iterations == 0)
                response.getHeader().setFlag(Flags.AA);
        }
        rcode = Rcode.NXDOMAIN;
    } else if (sr.isNXRRSET()) {
        if (zone != null) {
            addSOA(response, zone);
            if (iterations == 0)
                response.getHeader().setFlag(Flags.AA);
        }
    } else if (sr.isDelegation()) {
        final RRset nsRecords = sr.getNS();
        addRRset(nsRecords.getName(), response, nsRecords, Section.AUTHORITY, flags);
    } else if (sr.isCNAME()) {
        final CNAMERecord cname = sr.getCNAME();
        addRRset(name, response, new RRset(cname), Section.ANSWER, flags);
        if (zone != null && iterations == 0)
            response.getHeader().setFlag(Flags.AA);
        rcode = addAnswer(response, cname.getTarget(), type, dclass, iterations + 1, flags);
    } else if (sr.isDNAME()) {
        final DNAMERecord dname = sr.getDNAME();
        RRset rrset = new RRset(dname);
        addRRset(name, response, rrset, Section.ANSWER, flags);
        final Name newname;
        try {
            newname = name.fromDNAME(dname);
        } catch (final NameTooLongException e) {
            return Rcode.YXDOMAIN;
        }
        rrset = new RRset(new CNAMERecord(name, dclass, 0, newname));
        addRRset(name, response, rrset, Section.ANSWER, flags);
        if (zone != null && iterations == 0)
            response.getHeader().setFlag(Flags.AA);
        rcode = addAnswer(response, newname, type, dclass, iterations + 1, flags);
    } else if (sr.isSuccessful()) {
        final RRset[] rrsets = sr.answers();
        for (int i = 0; i < rrsets.length; i++) addRRset(name, response, rrsets[i], Section.ANSWER, flags);
        if (zone != null) {
            addNS(response, zone, flags);
            if (iterations == 0)
                response.getHeader().setFlag(Flags.AA);
        } else
            addCacheNS(response, getCache(dclass), name);
    }
    return rcode;
}