@SuppressWarnings("unchecked")
private static void addRRset(
Name name, final Message response, Record[] records, final int section) {
Multimap<RequestType, Record> rrsets = ArrayListMultimap.create();
for (Record r : records) {
RequestType type = RequestType.typeOf(r.getType());
rrsets.get(type).addAll(Collections2.filter(Arrays.asList(records), type));
}
Predicate<Record> checkNewRecord =
new Predicate<Record>() {
@Override
public boolean apply(Record input) {
for (int s = 1; s <= section; s++) {
if (response.findRecord(input, s)) {
return false;
}
}
return true;
}
};
if (rrsets.containsKey(RequestType.CNAME)) {
for (Record cnames : Iterables.filter(rrsets.removeAll(RequestType.CNAME), checkNewRecord)) {
response.addRecord(cnames, section);
}
}
for (Record sectionRecord : Iterables.filter(rrsets.values(), checkNewRecord)) {
response.addRecord(sectionRecord, section);
}
}
private static SetResponse lookupRecords(
final Message response, final Record query, final InetAddress source) {
final Name name = query.getName();
final int type = query.getType();
response.getHeader().setFlag(Flags.RA); // always mark the response w/ the recursion available
// bit
LOG.debug("DnsResolver: " + RequestType.typeOf(type) + " " + name);
for (final DnsResolver r : DnsResolvers.resolversFor(query, source)) {
try {
final DnsResponse reply = r.lookupRecords(query);
if (reply == null) {
LOG.debug("DnsResolver: returned null " + name + " using " + r);
continue;
}
if (reply.isAuthoritative()) { // mark
response.getHeader().setFlag(Flags.AA);
}
if (reply.isNxdomain()) {
addRRset(name, response, new Record[] {DomainNameRecords.sourceOfAuthority(name)}, type);
response.getHeader().setRcode(Rcode.NXDOMAIN);
return SetResponse.ofType(SetResponse.NXDOMAIN);
} else if (reply.hasAnswer()) {
for (ResponseSection s : ResponseSection.values()) {
Record[] records = reply.section(s);
if (records != null) {
addRRset(name, response, records, s.section());
}
}
return SetResponse.ofType(SetResponse.SUCCESSFUL);
}
} catch (final Exception ex) {
LOG.debug(
"DnsResolver: failed for " + name + " using " + r + " because of: " + ex.getMessage(),
ex);
}
}
return SetResponse.ofType(SetResponse.UNKNOWN); // no dice, return unknown
}
