Example usage for io.netty.handler.codec.dns DnsRecord timeToLive

Introduction

In this page you can find the example usage for io.netty.handler.codec.dns DnsRecord timeToLive.

Prototype

long timeToLive();

Source Link

Document

Returns the time to live after reading for this resource record.

Usage

From source file:io.vertx.core.dns.impl.fix.DnsNameResolverContext.java

License:Apache License

private void onResponseAorAAAA(DnsRecordType qType, DnsQuestion question,
        AddressedEnvelope<DnsResponse, InetSocketAddress> envelope) {

    // 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;
        }/*from w ww. j  a  v  a2 s  .c o  m*/

        final String qName = question.name().toLowerCase(Locale.US);
        final String rName = r.name().toLowerCase(Locale.US);

        // Make sure the record is for the questioned domain.
        if (!rName.equals(qName)) {
            // Even if the record's name is not exactly same, it might be an alias defined in the CNAME records.
            String resolved = qName;
            do {
                resolved = cnames.get(resolved);
                if (rName.equals(resolved)) {
                    break;
                }
            } while (resolved != null);

            if (resolved == null) {
                continue;
            }
        }

        if (!(r instanceof DnsRawRecord)) {
            continue;
        }

        final ByteBuf content = ((ByteBufHolder) r).content();
        final int contentLen = content.readableBytes();
        if (contentLen != INADDRSZ4 && contentLen != INADDRSZ6) {
            continue;
        }

        final byte[] addrBytes = new byte[contentLen];
        content.getBytes(content.readerIndex(), addrBytes);

        final InetAddress resolved;
        try {
            resolved = InetAddress.getByAddress(hostname, addrBytes);
        } catch (UnknownHostException e) {
            // Should never reach here.
            throw new Error(e);
        }

        if (resolvedEntries == null) {
            resolvedEntries = new ArrayList<DnsCacheEntry>(8);
        }

        final DnsCacheEntry e = new DnsCacheEntry(hostname, resolved);
        resolveCache.cache(hostname, 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);
    }
}

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