/* Returns true if the message could be rendered. */
private boolean toWire(DNSOutput out, int maxLength) {
if (maxLength < Header.LENGTH) return false;
Header newheader = null;
int tempMaxLength = maxLength;
if (tsigkey != null) tempMaxLength -= tsigkey.recordLength();
OPTRecord opt = getOPT();
byte[] optBytes = null;
if (opt != null) {
optBytes = opt.toWire(Section.ADDITIONAL);
tempMaxLength -= optBytes.length;
}
int startpos = out.current();
header.toWire(out);
Compression c = new Compression();
int flags = header.getFlagsByte();
int additionalCount = 0;
for (int i = 0; i < 4; i++) {
int skipped;
if (sections[i] == null) continue;
skipped = sectionToWire(out, i, c, tempMaxLength);
if (skipped != 0 && i != Section.ADDITIONAL) {
flags = Header.setFlag(flags, Flags.TC, true);
out.writeU16At(header.getCount(i) - skipped, startpos + 4 + 2 * i);
for (int j = i + 1; j < Section.ADDITIONAL; j++) out.writeU16At(0, startpos + 4 + 2 * j);
break;
}
if (i == Section.ADDITIONAL) additionalCount = header.getCount(i) - skipped;
}
if (optBytes != null) {
out.writeByteArray(optBytes);
additionalCount++;
}
if (flags != header.getFlagsByte()) out.writeU16At(flags, startpos + 2);
if (additionalCount != header.getCount(Section.ADDITIONAL))
out.writeU16At(additionalCount, startpos + 10);
if (tsigkey != null) {
TSIGRecord tsigrec = tsigkey.generate(this, out.toByteArray(), tsigerror, querytsig);
tsigrec.toWire(out, Section.ADDITIONAL, c);
out.writeU16At(additionalCount + 1, startpos + 10);
}
return true;
}
/* Returns true if the message could be rendered. */
private boolean toWire(DNSOutput out, int maxLength) {
if (maxLength < Header.LENGTH) return false;
Header newheader = null;
int tempMaxLength = maxLength;
if (tsigkey != null) tempMaxLength -= tsigkey.recordLength();
int startpos = out.current();
header.toWire(out);
Compression c = new Compression();
for (int i = 0; i < 4; i++) {
int skipped;
if (sections[i] == null) continue;
skipped = sectionToWire(out, i, c, tempMaxLength);
if (skipped != 0) {
if (i != Section.ADDITIONAL) {
if (newheader == null) newheader = (Header) header.clone();
newheader.setFlag(Flags.TC);
int count = newheader.getCount(i);
newheader.setCount(i, count - skipped);
for (int j = i + 1; j < 4; j++) newheader.setCount(j, 0);
out.save();
out.jump(startpos);
newheader.toWire(out);
out.restore();
}
break;
}
}
if (tsigkey != null) {
TSIGRecord tsigrec = tsigkey.generate(this, out.toByteArray(), tsigerror, querytsig);
if (newheader == null) newheader = (Header) header.clone();
tsigrec.toWire(out, Section.ADDITIONAL, c);
newheader.incCount(Section.ADDITIONAL);
out.save();
out.jump(startpos);
newheader.toWire(out);
out.restore();
}
return true;
}
/**
* 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);
}
private void verifyTSIG(Message query, Message response, byte[] b, TSIG tsig) {
if (tsig == null) return;
int error = tsig.verify(response, b, query.getTSIG());
if (Options.check("verbose")) System.err.println("TSIG verify: " + Rcode.TSIGstring(error));
}