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

Example 11 with Message

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

the class NameResolution method forwardToDnsServer.

/**
   * Sends the query to the DNS server.
   *
   * @param dnsServer
   * @param query
   * @return A message with either a good response or an error.
   */
public static Message forwardToDnsServer(SimpleResolver dnsServer, Message query) {
    try {
        Message dnsResponse = dnsServer.send(query);
        NameResolution.getLogger().log(Level.FINE, "DNS response {0} with {1} answer, {2} authoritative and {3} additional records", new Object[] { Rcode.string(dnsResponse.getHeader().getRcode()), dnsResponse.getSectionArray(Section.ANSWER).length, dnsResponse.getSectionArray(Section.AUTHORITY).length, dnsResponse.getSectionArray(Section.ADDITIONAL).length });
        if (isReasonableResponse(dnsResponse)) {
            NameResolution.getLogger().log(Level.FINE, "Outgoing response from DNS: {0}", dnsResponse.toString());
            return dnsResponse;
        }
    } catch (IOException e) {
        NameResolution.getLogger().log(Level.WARNING, "DNS resolution failed for {0}: {1}", new Object[] { query, e });
    }
    return errorMessage(query, Rcode.NXDOMAIN);
}

Example 12 with Message

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

the class NameResolution method lookupGnsServer.

/**
   * Lookup the query in the GNS server.
   * @param addr 
   * @param query
   * @param handler
   * @return A message with either a good response or an error.
   */
public static Message lookupGnsServer(InetAddress addr, Message query, ClientRequestHandlerInterface handler) {
    // 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 int fieldName = query.getQuestion().getType();
    final Name requestedName = query.getQuestion().getName();
    final byte[] rawName = requestedName.toWire();
    final String domainName = querytoStringForGNS(rawName);
    // The domain name must be an absolute name, i.e., ended with a dot
    assert (domainName.endsWith(".")) : "The domain name " + domainName + "to resolve is not an absolute name!";
    /**
     *  The query type or domain name can't be null, otherwise return an error message
     */
    if (Type.string(fieldName) == null || domainName == null) {
        return errorMessage(query, Rcode.NXDOMAIN);
    }
    NameResolution.getLogger().log(Level.FINE, "Trying GNS lookup for domain {0}, type {1}", new Object[] { domainName, Type.string(fieldName) });
    /**
     *  Create a response message, build the header first.
     *  The response is constructed later after GNS query.
     */
    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);
    /**
     * Request DNS fields of an alias and prepare a DNS response message 
     */
    ArrayList<String> fields = new ArrayList<>(Arrays.asList("A", "NS", "CNAME", "SOA", "PTR", "MX"));
    /**
     * <p>
     * RFC 1034: the additional section "carries RRs(Resource Records) which may be helpful in
     * 			using the RRs in the other section"
     * RFC 2181: data you put in the additional section can never be promoted into real answers.
     * 
     * <p>When a DNS client needs to look up a name used in a program, it queries DNS servers to resolve the name. 
     * Each query message the client sends contains three pieces of information, specifying a question for the server to answer:
     * 1. A specified DNS domain name, stated as a fully qualified domain name (FQDN).
     * 2. A specified query type, which can either specify a resource record (RR) by type or a specialized type of query operation.
     * 3. A specified class for the DNS domain name. For DNS servers running the Windows operating system, this should always be specified as the Internet (IN) class.
     * 
     * <p>The information is retrieved from GNS based on the queried domain.
     * <p>The response is constructed based on the query type,
     * 1. A: return A records in ANSWER section, NS records in AUTHORITY section, A records of name servers in ADDITIONAL section
     * 2. NS: return NS records in ANSWER section, A records of name servers in ADDITIONAL section
     * 3. MX: return MX records in ANSWER section, NS records in AUTHORITY section, A record of name servers in ADDITIONAL section
     * 4. CNAME: return CNAME records in in ANSWER section, NS records in AUTHORITY section, A record of name servers in ADDITIONAL section
     * 
     * Records in ADDITIONAL section is not required, we do a best-effort resolution for the names in ADDITIONAL section.
     */
    long resolveStart = System.currentTimeMillis();
    JSONObject fieldResponseJson = lookupGuidField(addr.getHostAddress().toString(), query.getHeader().getID(), domainName, null, fields, handler);
    if (fieldResponseJson == null) {
        NameResolution.getLogger().log(Level.FINE, "GNS lookup for domain {0} failed.", domainName);
        return errorMessage(query, Rcode.NXDOMAIN);
    }
    NameResolution.getLogger().log(Level.FINE, "fieldResponse all fields (NS, MX, CNAME, A): {0}", fieldResponseJson.toString());
    switch(fieldName) {
        case Type.NS:
            {
                JSONObject obj = getNSRecordsFromNSField(fieldResponseJson, domainName);
                if (obj != null) {
                    try {
                        JSONArray nsList = obj.getJSONArray("NS");
                        JSONArray aList = obj.getJSONArray("A");
                        for (int i = 0; i < nsList.length(); i++) {
                            response.addRecord((Record) nsList.get(i), Section.ANSWER);
                        }
                        for (int i = 0; i < aList.length(); i++) {
                            response.addRecord((Record) aList.get(i), Section.ADDITIONAL);
                        }
                    } catch (JSONException e) {
                    // do nothing, this happens only because some record is corrupted
                    }
                } else {
                    // I don't have the requested A record, you must ask a wrong guy
                    return errorMessage(query, Rcode.NXDOMAIN);
                }
            }
            break;
        case Type.A:
            {
                // Get A records from retrieved GNS record
                JSONArray aList = getARecordsFromAField(fieldResponseJson, domainName);
                if (aList != null) {
                    for (int i = 0; i < aList.length(); i++) {
                        try {
                            response.addRecord((Record) aList.get(i), Section.ANSWER);
                        } catch (JSONException e) {
                        // trash the record
                        }
                    }
                } else {
                    // I don't have the requested A record, you must ask a wrong guy
                    return errorMessage(query, Rcode.NXDOMAIN);
                }
                //Get NS record if we can
                JSONObject obj = getNSRecordsFromNSField(fieldResponseJson, domainName);
                if (obj != null) {
                    try {
                        JSONArray nsList = obj.getJSONArray("NS");
                        JSONArray aNSList = obj.getJSONArray("A");
                        for (int i = 0; i < nsList.length(); i++) {
                            response.addRecord((Record) nsList.get(i), Section.AUTHORITY);
                        }
                        for (int i = 0; i < aNSList.length(); i++) {
                            response.addRecord((Record) aNSList.get(i), Section.ADDITIONAL);
                        }
                    } catch (JSONException e) {
                    // do nothing, this happens only because some record is corrupted
                    }
                }
            }
            break;
        case Type.MX:
            {
                JSONObject obj = getMXRecordsFromMXField(fieldResponseJson, domainName);
                NameResolution.getLogger().log(Level.FINE, "MX record for domain {0} is {1}", new Object[] { domainName, obj });
                if (obj != null) {
                    try {
                        JSONArray mxList = obj.getJSONArray("MX");
                        JSONArray aList = obj.getJSONArray("A");
                        for (int i = 0; i < mxList.length(); i++) {
                            response.addRecord((Record) mxList.get(i), Section.ANSWER);
                        }
                        for (int i = 0; i < aList.length(); i++) {
                            response.addRecord((Record) aList.get(i), Section.ADDITIONAL);
                        }
                    } catch (JSONException e) {
                    // do nothing, this happens only because some record is corrupted
                    }
                } else {
                    // I don't have the requested MX record, you must ask a wrong guy
                    return errorMessage(query, Rcode.NXDOMAIN);
                }
                //Get NS record if we can
                obj = getNSRecordsFromNSField(fieldResponseJson, domainName);
                if (obj != null) {
                    try {
                        JSONArray nsList = obj.getJSONArray("NS");
                        JSONArray aNSList = obj.getJSONArray("A");
                        for (int i = 0; i < nsList.length(); i++) {
                            response.addRecord((Record) nsList.get(i), Section.AUTHORITY);
                        }
                        for (int i = 0; i < aNSList.length(); i++) {
                            response.addRecord((Record) aNSList.get(i), Section.ADDITIONAL);
                        }
                    } catch (JSONException e) {
                    // do nothing, this happens only because some record is corrupted
                    }
                }
            }
            break;
        case Type.CNAME:
            {
                if (fieldResponseJson.has("CNAME")) {
                    // get CNAME alias, no need to resolve it to an IP address
                    try {
                        String cname = fieldResponseJson.getString("CNAME");
                        // The cname must be an absolute name, i.e., ended with a dot
                        if (!cname.endsWith(".")) {
                            cname = cname + ".";
                        }
                        CNAMERecord cnameRecord = new CNAMERecord(new Name(domainName), DClass.IN, 60, new Name(cname));
                        response.addRecord(cnameRecord, Section.ANSWER);
                    } catch (JSONException | TextParseException e) {
                    }
                } else {
                    // I don't have the requested CNAME record, you must ask a wrong guy
                    return errorMessage(query, Rcode.NXDOMAIN);
                }
            }
            break;
        default:
            // we haven't implemented yet
            return errorMessage(query, Rcode.NOTIMPL);
    }
    DelayProfiler.updateDelay("ResolveName", resolveStart);
    NameResolution.getLogger().log(Level.FINER, "Outgoing response from GNS: {0}", response.toString());
    return response;
}

Example 13 with Message

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

the class NameResolution method buildErrorMessage.

/**
   * Creates an error message from a header, response code and a record.
   *
   * @param header
   * @param rcode
   * @param question
   * @return the error message
   */
private static Message buildErrorMessage(Header header, int rcode, Record question) {
    Message response = new Message();
    response.setHeader(header);
    for (int i = 0; i < 4; i++) {
        response.removeAllRecords(i);
    }
    if (question != null) {
        response.addRecord(question, Section.QUESTION);
    }
    response.getHeader().setRcode(rcode);
    return response;
}

Example 14 with Message

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

the class DNSServer method doAXFR.

byte[] doAXFR(final Name name, final Message query, final TSIG tsig, TSIGRecord qtsig, final Socket s) {
    final Zone zone = m_znames.get(name);
    boolean first = true;
    if (zone == null)
        return errorMessage(query, Rcode.REFUSED);
    @SuppressWarnings("unchecked") final Iterator<RRset> it = zone.AXFR();
    try {
        final DataOutputStream dataOut = new DataOutputStream(s.getOutputStream());
        int id = query.getHeader().getID();
        while (it.hasNext()) {
            final RRset rrset = it.next();
            final Message response = new Message(id);
            final Header header = response.getHeader();
            header.setFlag(Flags.QR);
            header.setFlag(Flags.AA);
            addRRset(rrset.getName(), response, rrset, Section.ANSWER, FLAG_DNSSECOK);
            if (tsig != null) {
                tsig.applyStream(response, qtsig, first);
                qtsig = response.getTSIG();
            }
            first = false;
            final byte[] out = response.toWire();
            dataOut.writeShort(out.length);
            dataOut.write(out);
        }
    } catch (final IOException ex) {
        LOG.warn("AXFR failed", ex);
    }
    try {
        s.close();
    } catch (final IOException ex) {
        LOG.warn("error closing socket", ex);
    }
    return null;
}

Example 15 with Message

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

the class DNSServer method generateReply.

/*
     * 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.
     */
byte[] generateReply(final Message query, final byte[] in, final int length, final Socket s) throws IOException {
    final Header header = query.getHeader();
    int maxLength;
    int flags = 0;
    if (header.getFlag(Flags.QR))
        return null;
    if (header.getRcode() != Rcode.NOERROR)
        return errorMessage(query, Rcode.FORMERR);
    if (header.getOpcode() != Opcode.QUERY)
        return errorMessage(query, Rcode.NOTIMP);
    final Record queryRecord = query.getQuestion();
    final TSIGRecord queryTSIG = query.getTSIG();
    TSIG tsig = null;
    if (queryTSIG != null) {
        tsig = m_TSIGs.get(queryTSIG.getName());
        if (tsig == null || tsig.verify(query, in, length, null) != Rcode.NOERROR)
            return formerrMessage(in);
    }
    final OPTRecord queryOPT = query.getOPT();
    if (s != null)
        maxLength = 65535;
    else if (queryOPT != null)
        maxLength = Math.max(queryOPT.getPayloadSize(), 512);
    else
        maxLength = 512;
    if (queryOPT != null && (queryOPT.getFlags() & ExtendedFlags.DO) != 0)
        flags = FLAG_DNSSECOK;
    final Message response = new Message(query.getHeader().getID());
    response.getHeader().setFlag(Flags.QR);
    if (query.getHeader().getFlag(Flags.RD)) {
        response.getHeader().setFlag(Flags.RD);
    }
    response.addRecord(queryRecord, Section.QUESTION);
    final Name name = queryRecord.getName();
    final int type = queryRecord.getType();
    final int dclass = queryRecord.getDClass();
    if ((type == Type.AXFR || type == Type.IXFR) && s != null)
        return doAXFR(name, query, tsig, queryTSIG, s);
    if (!Type.isRR(type) && type != Type.ANY)
        return errorMessage(query, Rcode.NOTIMP);
    final byte rcode = addAnswer(response, name, type, dclass, 0, flags);
    if (rcode != Rcode.NOERROR && rcode != Rcode.NXDOMAIN)
        return errorMessage(query, rcode);
    addAdditional(response, flags);
    if (queryOPT != null) {
        final int optflags = (flags == FLAG_DNSSECOK) ? ExtendedFlags.DO : 0;
        final OPTRecord opt = new OPTRecord((short) 4096, rcode, (byte) 0, optflags);
        response.addRecord(opt, Section.ADDITIONAL);
    }
    response.setTSIG(tsig, Rcode.NOERROR, queryTSIG);
    return response.toWire(maxLength);
}