private Message sendAXFR(Message query) throws IOException {
Name qname = query.getQuestion().getName();
ZoneTransferIn xfrin = ZoneTransferIn.newAXFR(qname, address, tsig);
xfrin.setTimeout((int) (getTimeout() / 1000));
xfrin.setLocalAddress(localAddress);
try {
xfrin.run();
} catch (ZoneTransferException e) {
throw new WireParseException(e.getMessage());
}
List records = xfrin.getAXFR();
Message response = new Message(query.getHeader().getID());
response.getHeader().setFlag(Flags.AA);
response.getHeader().setFlag(Flags.QR);
response.addRecord(query.getQuestion(), Section.QUESTION);
Iterator it = records.iterator();
while (it.hasNext()) response.addRecord((Record) it.next(), Section.ANSWER);
return response;
}
/**
* Asynchronously sends a message to a single server, registering a listener to receive a callback
* on success or exception. Multiple asynchronous lookups can be performed in parallel. Since the
* callback may be invoked before the function returns, external synchronization is necessary.
*
* @param query The query to send
* @param listener The object containing the callbacks.
* @return An identifier, which is also a parameter in the callback
*/
public Object sendAsync(final Message query, final ResolverListener listener) {
final Object id;
synchronized (this) {
id = new Integer(uniqueID++);
}
Record question = query.getQuestion();
String qname;
if (question != null) qname = question.getName().toString();
else qname = "(none)";
String name = this.getClass() + ": " + qname;
Thread thread = new ResolveThread(this, query, id, listener);
thread.setName(name);
thread.setDaemon(true);
thread.start();
return id;
}
private int uniqueID(Message m) {
Record r = m.getQuestion();
return (((r.getName().hashCode() & 0xFFFF) << 16)
+ (r.getType() + hashCode() << 8)
+ (hashCode() & 0xFF));
}
/**
* Adds all data from a Message into the Cache. Each record is added with the appropriate
* credibility, and negative answers are cached as such.
*
* @param in The Message to be added
* @see Message
*/
public void addMessage(Message in) {
boolean isAuth = in.getHeader().getFlag(Flags.AA);
Name qname = in.getQuestion().getName();
Name curname = qname;
short qtype = in.getQuestion().getType();
short qclass = in.getQuestion().getDClass();
byte cred;
short rcode = in.getHeader().getRcode();
boolean haveAnswer = false;
boolean completed = false;
boolean restart = false;
RRset[] answers, auth, addl;
if (rcode != Rcode.NOERROR && rcode != Rcode.NXDOMAIN) return;
if (secure) {
Cache c = new Cache(dclass);
c.addMessage(in);
verifyRecords(c);
return;
}
answers = in.getSectionRRsets(Section.ANSWER);
for (int i = 0; i < answers.length; i++) {
if (answers[i].getDClass() != qclass) continue;
short type = answers[i].getType();
Name name = answers[i].getName();
cred = getCred(Section.ANSWER, isAuth);
if (type == Type.CNAME && name.equals(curname)) {
CNAMERecord cname;
addRRset(answers[i], cred);
cname = (CNAMERecord) answers[i].first();
curname = cname.getTarget();
restart = true;
haveAnswer = true;
} else if (type == Type.DNAME && curname.subdomain(name)) {
DNAMERecord dname;
addRRset(answers[i], cred);
dname = (DNAMERecord) answers[i].first();
try {
curname = curname.fromDNAME(dname);
} catch (NameTooLongException e) {
break;
}
restart = true;
haveAnswer = true;
} else if ((type == qtype || qtype == Type.ANY) && name.equals(curname)) {
addRRset(answers[i], cred);
completed = true;
haveAnswer = true;
}
if (restart) {
restart = false;
i = 0;
}
}
auth = in.getSectionRRsets(Section.AUTHORITY);
if (!completed) {
/* This is a negative response or a referral. */
RRset soa = null, ns = null;
for (int i = 0; i < auth.length; i++) {
if (auth[i].getType() == Type.SOA && curname.subdomain(auth[i].getName())) soa = auth[i];
else if (auth[i].getType() == Type.NS && curname.subdomain(auth[i].getName())) ns = auth[i];
}
short cachetype = (rcode == Rcode.NXDOMAIN) ? (short) 0 : qtype;
if (soa != null || ns == null) {
/* Negative response */
cred = getCred(Section.AUTHORITY, isAuth);
SOARecord soarec = null;
if (soa != null) soarec = (SOARecord) soa.first();
addNegative(curname, cachetype, soarec, cred);
/* NXT records are not cached yet. */
} else {
/* Referral response */
cred = getCred(Section.AUTHORITY, isAuth);
addRRset(ns, cred);
}
}
addl = in.getSectionRRsets(Section.ADDITIONAL);
for (int i = 0; i < addl.length; i++) {
short type = addl[i].getType();
if (type != Type.A && type != Type.AAAA && type != Type.A6) continue;
/* XXX check the name */
Name name = addl[i].getName();
cred = getCred(Section.ADDITIONAL, isAuth);
addRRset(addl[i], cred);
}
}
/**
* Sends a message to a single server and waits for a response. No checking is done to ensure that
* the response is associated with the query.
*
* @param query The query to send.
* @return The response.
* @throws IOException An error occurred while sending or receiving.
*/
public Message send(Message query) throws IOException {
if (Options.check("verbose"))
System.err.println(
"Sending to " + address.getAddress().getHostAddress() + ":" + address.getPort());
if (query.getHeader().getOpcode() == Opcode.QUERY) {
Record question = query.getQuestion();
if (question != null && question.getType() == Type.AXFR) return sendAXFR(query);
}
query = (Message) query.clone();
applyEDNS(query);
if (tsig != null) {
tsig.apply(query, null);
}
byte[] out = query.toWire(Message.MAXLENGTH);
int udpSize = maxUDPSize(query);
boolean tcp = false;
long endTime = System.currentTimeMillis() + timeoutValue;
do {
byte[] b_in;
if (useTCP || out.length > udpSize) {
tcp = true;
}
if (tcp) {
b_in = TCPClient.sendrecv(localAddress, address, out, endTime);
} else {
b_in = UDPClient.sendrecv(localAddress, address, out, udpSize, endTime);
}
/*
* Check that the response is long enough.
*/
if (b_in.length < Header.LENGTH) {
throw new WireParseException("invalid DNS header - " + "too short");
}
/*
* Check that the response ID matches the query ID. We want
* to check this before actually parsing the message, so that
* if there's a malformed response that's not ours, it
* doesn't confuse us.
*/
int id = ((b_in[0] & 0xFF) << 8) + (b_in[1] & 0xFF);
int qid = query.getHeader().getID();
if (id != qid) {
String error = "invalid message id: expected " + qid + "; got id " + id;
if (tcp) {
throw new WireParseException(error);
} else {
if (Options.check("verbose")) {
System.err.println(error);
}
continue;
}
}
Message response = parseMessage(b_in);
verifyTSIG(query, response, b_in, tsig);
if (!tcp && !ignoreTruncation && response.getHeader().getFlag(Flags.TC)) {
tcp = true;
continue;
}
return response;
} while (true);
}
