Examples with DnsResponse io.netty.handler.codec.dns.DnsResponse used on opensource projects

Example 1 with DnsResponse

use of io.netty.handler.codec.dns.DnsResponse in project netty by netty.

the class DnsNameResolverTest method testQueryMx.

@Test
public void testQueryMx() throws Exception {
    DnsNameResolver resolver = newResolver().build();
    try {
        assertThat(resolver.isRecursionDesired(), is(true));
        Map<String, Future<AddressedEnvelope<DnsResponse, InetSocketAddress>>> futures = new LinkedHashMap<String, Future<AddressedEnvelope<DnsResponse, InetSocketAddress>>>();
        for (String name : DOMAINS) {
            if (EXCLUSIONS_QUERY_MX.contains(name)) {
                continue;
            }
            queryMx(resolver, futures, name);
        }
        for (Entry<String, Future<AddressedEnvelope<DnsResponse, InetSocketAddress>>> e : futures.entrySet()) {
            String hostname = e.getKey();
            Future<AddressedEnvelope<DnsResponse, InetSocketAddress>> f = e.getValue().awaitUninterruptibly();
            DnsResponse response = f.getNow().content();
            assertThat(response.code(), is(DnsResponseCode.NOERROR));
            final int answerCount = response.count(DnsSection.ANSWER);
            final List<DnsRecord> mxList = new ArrayList<DnsRecord>(answerCount);
            for (int i = 0; i < answerCount; i++) {
                final DnsRecord r = response.recordAt(DnsSection.ANSWER, i);
                if (r.type() == DnsRecordType.MX) {
                    mxList.add(r);
                }
            }
            assertThat(mxList.size(), is(greaterThan(0)));
            StringBuilder buf = new StringBuilder();
            for (DnsRecord r : mxList) {
                ByteBuf recordContent = ((ByteBufHolder) r).content();
                buf.append(StringUtil.NEWLINE);
                buf.append('\t');
                buf.append(r.name());
                buf.append(' ');
                buf.append(r.type().name());
                buf.append(' ');
                buf.append(recordContent.readUnsignedShort());
                buf.append(' ');
                buf.append(DnsNameResolverContext.decodeDomainName(recordContent));
            }
            logger.info("{} has the following MX records:{}", hostname, buf);
            response.release();
        }
    } finally {
        resolver.close();
    }
}

Example 2 with DnsResponse

use of io.netty.handler.codec.dns.DnsResponse in project netty by netty.

the class DnsNameResolverContext method onResponseAorAAAA.

private void onResponseAorAAAA(DnsRecordType qType, DnsQuestion question, AddressedEnvelope<DnsResponse, InetSocketAddress> envelope, Promise<T> promise) {
    // We often get a bunch of CNAMES as well when we asked for A/AAAA.
    final DnsResponse response = envelope.content();
    final Map<String, String> cnames = buildAliasMap(response);
    final int answerCount = response.count(DnsSection.ANSWER);
    boolean found = false;
    for (int i = 0; i < answerCount; i++) {
        final DnsRecord r = response.recordAt(DnsSection.ANSWER, i);
        final DnsRecordType type = r.type();
        if (type != DnsRecordType.A && type != DnsRecordType.AAAA) {
            continue;
        }
        final String questionName = question.name().toLowerCase(Locale.US);
        final String recordName = r.name().toLowerCase(Locale.US);
        // Make sure the record is for the questioned domain.
        if (!recordName.equals(questionName)) {
            // Even if the record's name is not exactly same, it might be an alias defined in the CNAME records.
            String resolved = questionName;
            do {
                resolved = cnames.get(resolved);
                if (recordName.equals(resolved)) {
                    break;
                }
            } while (resolved != null);
            if (resolved == null) {
                continue;
            }
        }
        InetAddress resolved = parseAddress(r, hostname);
        if (resolved == null) {
            continue;
        }
        if (resolvedEntries == null) {
            resolvedEntries = new ArrayList<DnsCacheEntry>(8);
        }
        final DnsCacheEntry e = new DnsCacheEntry(hostname, resolved);
        resolveCache.cache(hostname, additionals, resolved, r.timeToLive(), parent.ch.eventLoop());
        resolvedEntries.add(e);
        found = true;
    // Note that we do not break from the loop here, so we decode/cache all A/AAAA records.
    }
    if (found) {
        return;
    }
    if (traceEnabled) {
        addTrace(envelope.sender(), "no matching " + qType + " record found");
    }
    // We aked for A/AAAA but we got only CNAME.
    if (!cnames.isEmpty()) {
        onResponseCNAME(question, envelope, cnames, false, promise);
    }
}

Example 3 with DnsResponse

use of io.netty.handler.codec.dns.DnsResponse in project netty by netty.

the class DnsNameResolverContext method handleRedirect.

/**
     * Handle redirects if needed and returns {@code true} if there was a redirect handled. If {@code true} is returned
     * this method took ownership of the {@code promise} otherwise {@code false} is returned.
     */
private boolean handleRedirect(DnsQuestion question, AddressedEnvelope<DnsResponse, InetSocketAddress> envelope, Promise<T> promise) {
    final DnsResponse res = envelope.content();
    // Check if we have answers, if not this may be an non authority NS and so redirects must be handled.
    if (res.count(DnsSection.ANSWER) == 0) {
        AuthoritativeNameServerList serverNames = extractAuthoritativeNameServers(question.name(), res);
        if (serverNames != null) {
            List<InetSocketAddress> nameServers = new ArrayList<InetSocketAddress>(serverNames.size());
            int additionalCount = res.count(DnsSection.ADDITIONAL);
            for (int i = 0; i < additionalCount; i++) {
                final DnsRecord r = res.recordAt(DnsSection.ADDITIONAL, i);
                if ((r.type() == DnsRecordType.A && !parent.supportsARecords()) || r.type() == DnsRecordType.AAAA && !parent.supportsAAAARecords()) {
                    continue;
                }
                final String recordName = r.name();
                AuthoritativeNameServer authoritativeNameServer = serverNames.remove(recordName);
                if (authoritativeNameServer == null) {
                    // Not a server we are interested in.
                    continue;
                }
                InetAddress resolved = parseAddress(r, recordName);
                if (resolved == null) {
                    // Could not parse it, move to the next.
                    continue;
                }
                nameServers.add(new InetSocketAddress(resolved, parent.dnsRedirectPort(resolved)));
                addNameServerToCache(authoritativeNameServer, resolved, r.timeToLive());
            }
            if (nameServers.isEmpty()) {
                promise.tryFailure(new UnknownHostException("Unable to find correct name server for " + hostname));
            } else {
                // Shuffle as we want to re-distribute the load across name servers.
                query(DnsServerAddresses.shuffled(nameServers).stream(), question, promise);
            }
            return true;
        }
    }
    return false;
}

Example 4 with DnsResponse

use of io.netty.handler.codec.dns.DnsResponse in project netty by netty.

the class DnsNameResolverContext method onResponse.

void onResponse(final DnsServerAddressStream nameServerAddrStream, final DnsQuestion question, AddressedEnvelope<DnsResponse, InetSocketAddress> envelope, Promise<T> promise) {
    try {
        final DnsResponse res = envelope.content();
        final DnsResponseCode code = res.code();
        if (code == DnsResponseCode.NOERROR) {
            if (handleRedirect(question, envelope, promise)) {
                // Was a redirect so return here as everything else is handled in handleRedirect(...)
                return;
            }
            final DnsRecordType type = question.type();
            if (type == DnsRecordType.A || type == DnsRecordType.AAAA) {
                onResponseAorAAAA(type, question, envelope, promise);
            } else if (type == DnsRecordType.CNAME) {
                onResponseCNAME(question, envelope, promise);
            }
            return;
        }
        if (traceEnabled) {
            addTrace(envelope.sender(), "response code: " + code + " with " + res.count(DnsSection.ANSWER) + " answer(s) and " + res.count(DnsSection.AUTHORITY) + " authority resource(s)");
        }
        // Retry with the next server if the server did not tell us that the domain does not exist.
        if (code != DnsResponseCode.NXDOMAIN) {
            query(nameServerAddrStream, question, promise);
        }
    } finally {
        ReferenceCountUtil.safeRelease(envelope);
    }
}

Example 5 with DnsResponse

use of io.netty.handler.codec.dns.DnsResponse in project netty by netty.

the class DnsQueryContext method finish.

void finish(AddressedEnvelope<? extends DnsResponse, InetSocketAddress> envelope) {
    final DnsResponse res = envelope.content();
    if (res.count(DnsSection.QUESTION) != 1) {
        logger.warn("Received a DNS response with invalid number of questions: {}", envelope);
        return;
    }
    if (!question().equals(res.recordAt(DnsSection.QUESTION))) {
        logger.warn("Received a mismatching DNS response: {}", envelope);
        return;
    }
    setSuccess(envelope);
}