743 lines
26 KiB
Java
743 lines
26 KiB
Java
/*
|
|
* Copyright (c) 2000, 2015, Oracle and/or its affiliates. All rights reserved.
|
|
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
|
|
*
|
|
* This code is free software; you can redistribute it and/or modify it
|
|
* under the terms of the GNU General Public License version 2 only, as
|
|
* published by the Free Software Foundation. Oracle designates this
|
|
* particular file as subject to the "Classpath" exception as provided
|
|
* by Oracle in the LICENSE file that accompanied this code.
|
|
*
|
|
* This code is distributed in the hope that it will be useful, but WITHOUT
|
|
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
|
|
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
|
|
* version 2 for more details (a copy is included in the LICENSE file that
|
|
* accompanied this code).
|
|
*
|
|
* You should have received a copy of the GNU General Public License version
|
|
* 2 along with this work; if not, write to the Free Software Foundation,
|
|
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
|
|
*
|
|
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
|
|
* or visit www.oracle.com if you need additional information or have any
|
|
* questions.
|
|
*/
|
|
|
|
package com.sun.jndi.dns;
|
|
|
|
import java.io.IOException;
|
|
import java.net.DatagramSocket;
|
|
import java.net.DatagramPacket;
|
|
import java.net.InetAddress;
|
|
import java.net.Socket;
|
|
import java.security.SecureRandom;
|
|
import javax.naming.*;
|
|
|
|
import java.util.Collections;
|
|
import java.util.Map;
|
|
import java.util.HashMap;
|
|
|
|
import sun.security.jca.JCAUtil;
|
|
|
|
// Some of this code began life as part of sun.javaos.net.DnsClient
|
|
// originally by sritchie@eng 1/96. It was first hacked up for JNDI
|
|
// use by caveh@eng 6/97.
|
|
|
|
|
|
/**
|
|
* The DnsClient class performs DNS client operations in support of DnsContext.
|
|
*
|
|
*/
|
|
|
|
public class DnsClient {
|
|
|
|
// DNS packet header field offsets
|
|
private static final int IDENT_OFFSET = 0;
|
|
private static final int FLAGS_OFFSET = 2;
|
|
private static final int NUMQ_OFFSET = 4;
|
|
private static final int NUMANS_OFFSET = 6;
|
|
private static final int NUMAUTH_OFFSET = 8;
|
|
private static final int NUMADD_OFFSET = 10;
|
|
private static final int DNS_HDR_SIZE = 12;
|
|
|
|
// DNS response codes
|
|
private static final int NO_ERROR = 0;
|
|
private static final int FORMAT_ERROR = 1;
|
|
private static final int SERVER_FAILURE = 2;
|
|
private static final int NAME_ERROR = 3;
|
|
private static final int NOT_IMPL = 4;
|
|
private static final int REFUSED = 5;
|
|
|
|
private static final String[] rcodeDescription = {
|
|
"No error",
|
|
"DNS format error",
|
|
"DNS server failure",
|
|
"DNS name not found",
|
|
"DNS operation not supported",
|
|
"DNS service refused"
|
|
};
|
|
|
|
private static final int DEFAULT_PORT = 53;
|
|
private static final int TRANSACTION_ID_BOUND = 0x10000;
|
|
private static final SecureRandom random = JCAUtil.getSecureRandom();
|
|
private InetAddress[] servers;
|
|
private int[] serverPorts;
|
|
private int timeout; // initial timeout on UDP queries in ms
|
|
private int retries; // number of UDP retries
|
|
|
|
private final Object udpSocketLock = new Object();
|
|
private static final DNSDatagramSocketFactory factory =
|
|
new DNSDatagramSocketFactory(random);
|
|
|
|
// Requests sent
|
|
private Map<Integer, ResourceRecord> reqs;
|
|
|
|
// Responses received
|
|
private Map<Integer, byte[]> resps;
|
|
|
|
//-------------------------------------------------------------------------
|
|
|
|
/*
|
|
* Each server is of the form "server[:port]". IPv6 literal host names
|
|
* include delimiting brackets.
|
|
* "timeout" is the initial timeout interval (in ms) for UDP queries,
|
|
* and "retries" gives the number of retries per server.
|
|
*/
|
|
public DnsClient(String[] servers, int timeout, int retries)
|
|
throws NamingException {
|
|
this.timeout = timeout;
|
|
this.retries = retries;
|
|
this.servers = new InetAddress[servers.length];
|
|
serverPorts = new int[servers.length];
|
|
|
|
for (int i = 0; i < servers.length; i++) {
|
|
|
|
// Is optional port given?
|
|
int colon = servers[i].indexOf(':',
|
|
servers[i].indexOf(']') + 1);
|
|
|
|
serverPorts[i] = (colon < 0)
|
|
? DEFAULT_PORT
|
|
: Integer.parseInt(servers[i].substring(colon + 1));
|
|
String server = (colon < 0)
|
|
? servers[i]
|
|
: servers[i].substring(0, colon);
|
|
try {
|
|
this.servers[i] = InetAddress.getByName(server);
|
|
} catch (java.net.UnknownHostException e) {
|
|
NamingException ne = new ConfigurationException(
|
|
"Unknown DNS server: " + server);
|
|
ne.setRootCause(e);
|
|
throw ne;
|
|
}
|
|
}
|
|
reqs = Collections.synchronizedMap(
|
|
new HashMap<Integer, ResourceRecord>());
|
|
resps = Collections.synchronizedMap(new HashMap<Integer, byte[]>());
|
|
}
|
|
|
|
DatagramSocket getDatagramSocket() throws NamingException {
|
|
try {
|
|
return factory.open();
|
|
} catch (java.net.SocketException e) {
|
|
NamingException ne = new ConfigurationException();
|
|
ne.setRootCause(e);
|
|
throw ne;
|
|
}
|
|
}
|
|
|
|
protected void finalize() {
|
|
close();
|
|
}
|
|
|
|
// A lock to access the request and response queues in tandem.
|
|
private Object queuesLock = new Object();
|
|
|
|
public void close() {
|
|
synchronized (queuesLock) {
|
|
reqs.clear();
|
|
resps.clear();
|
|
}
|
|
}
|
|
|
|
/*
|
|
* If recursion is true, recursion is requested on the query.
|
|
* If auth is true, only authoritative responses are accepted; other
|
|
* responses throw NameNotFoundException.
|
|
*/
|
|
ResourceRecords query(DnsName fqdn, int qclass, int qtype,
|
|
boolean recursion, boolean auth)
|
|
throws NamingException {
|
|
|
|
int xid;
|
|
Packet pkt;
|
|
ResourceRecord collision;
|
|
|
|
do {
|
|
// Generate a random transaction ID
|
|
xid = random.nextInt(TRANSACTION_ID_BOUND);
|
|
pkt = makeQueryPacket(fqdn, xid, qclass, qtype, recursion);
|
|
|
|
// enqueue the outstanding request
|
|
collision = reqs.putIfAbsent(xid, new ResourceRecord(pkt.getData(),
|
|
pkt.length(), Header.HEADER_SIZE, true, false));
|
|
|
|
} while (collision != null);
|
|
|
|
Exception caughtException = null;
|
|
boolean[] doNotRetry = new boolean[servers.length];
|
|
|
|
try {
|
|
//
|
|
// The UDP retry strategy is to try the 1st server, and then
|
|
// each server in order. If no answer, double the timeout
|
|
// and try each server again.
|
|
//
|
|
for (int retry = 0; retry < retries; retry++) {
|
|
|
|
// Try each name server.
|
|
for (int i = 0; i < servers.length; i++) {
|
|
if (doNotRetry[i]) {
|
|
continue;
|
|
}
|
|
|
|
// send the request packet and wait for a response.
|
|
try {
|
|
if (debug) {
|
|
dprint("SEND ID (" + (retry + 1) + "): " + xid);
|
|
}
|
|
|
|
byte[] msg = null;
|
|
msg = doUdpQuery(pkt, servers[i], serverPorts[i],
|
|
retry, xid);
|
|
//
|
|
// If the matching response is not got within the
|
|
// given timeout, check if the response was enqueued
|
|
// by some other thread, if not proceed with the next
|
|
// server or retry.
|
|
//
|
|
if (msg == null) {
|
|
if (resps.size() > 0) {
|
|
msg = lookupResponse(xid);
|
|
}
|
|
if (msg == null) { // try next server or retry
|
|
continue;
|
|
}
|
|
}
|
|
Header hdr = new Header(msg, msg.length);
|
|
|
|
if (auth && !hdr.authoritative) {
|
|
caughtException = new NameNotFoundException(
|
|
"DNS response not authoritative");
|
|
doNotRetry[i] = true;
|
|
continue;
|
|
}
|
|
if (hdr.truncated) { // message is truncated -- try TCP
|
|
|
|
// Try each server, starting with the one that just
|
|
// provided the truncated message.
|
|
for (int j = 0; j < servers.length; j++) {
|
|
int ij = (i + j) % servers.length;
|
|
if (doNotRetry[ij]) {
|
|
continue;
|
|
}
|
|
try {
|
|
Tcp tcp =
|
|
new Tcp(servers[ij], serverPorts[ij]);
|
|
byte[] msg2;
|
|
try {
|
|
msg2 = doTcpQuery(tcp, pkt);
|
|
} finally {
|
|
tcp.close();
|
|
}
|
|
Header hdr2 = new Header(msg2, msg2.length);
|
|
if (hdr2.query) {
|
|
throw new CommunicationException(
|
|
"DNS error: expecting response");
|
|
}
|
|
checkResponseCode(hdr2);
|
|
|
|
if (!auth || hdr2.authoritative) {
|
|
// Got a valid response
|
|
hdr = hdr2;
|
|
msg = msg2;
|
|
break;
|
|
} else {
|
|
doNotRetry[ij] = true;
|
|
}
|
|
} catch (Exception e) {
|
|
// Try next server, or use UDP response
|
|
}
|
|
} // servers
|
|
}
|
|
return new ResourceRecords(msg, msg.length, hdr, false);
|
|
|
|
} catch (IOException e) {
|
|
if (debug) {
|
|
dprint("Caught IOException:" + e);
|
|
}
|
|
if (caughtException == null) {
|
|
caughtException = e;
|
|
}
|
|
// Use reflection to allow pre-1.4 compilation.
|
|
// This won't be needed much longer.
|
|
if (e.getClass().getName().equals(
|
|
"java.net.PortUnreachableException")) {
|
|
doNotRetry[i] = true;
|
|
}
|
|
} catch (NameNotFoundException e) {
|
|
// This is authoritative, so return immediately
|
|
throw e;
|
|
} catch (CommunicationException e) {
|
|
if (caughtException == null) {
|
|
caughtException = e;
|
|
}
|
|
} catch (NamingException e) {
|
|
if (caughtException == null) {
|
|
caughtException = e;
|
|
}
|
|
doNotRetry[i] = true;
|
|
}
|
|
} // servers
|
|
} // retries
|
|
|
|
} finally {
|
|
reqs.remove(xid); // cleanup
|
|
}
|
|
|
|
if (caughtException instanceof NamingException) {
|
|
throw (NamingException) caughtException;
|
|
}
|
|
// A network timeout or other error occurred.
|
|
NamingException ne = new CommunicationException("DNS error");
|
|
ne.setRootCause(caughtException);
|
|
throw ne;
|
|
}
|
|
|
|
ResourceRecords queryZone(DnsName zone, int qclass, boolean recursion)
|
|
throws NamingException {
|
|
|
|
int xid = random.nextInt(TRANSACTION_ID_BOUND);
|
|
|
|
Packet pkt = makeQueryPacket(zone, xid, qclass,
|
|
ResourceRecord.QTYPE_AXFR, recursion);
|
|
Exception caughtException = null;
|
|
|
|
// Try each name server.
|
|
for (int i = 0; i < servers.length; i++) {
|
|
try {
|
|
Tcp tcp = new Tcp(servers[i], serverPorts[i]);
|
|
byte[] msg;
|
|
try {
|
|
msg = doTcpQuery(tcp, pkt);
|
|
Header hdr = new Header(msg, msg.length);
|
|
// Check only rcode as per
|
|
// draft-ietf-dnsext-axfr-clarify-04
|
|
checkResponseCode(hdr);
|
|
ResourceRecords rrs =
|
|
new ResourceRecords(msg, msg.length, hdr, true);
|
|
if (rrs.getFirstAnsType() != ResourceRecord.TYPE_SOA) {
|
|
throw new CommunicationException(
|
|
"DNS error: zone xfer doesn't begin with SOA");
|
|
}
|
|
|
|
if (rrs.answer.size() == 1 ||
|
|
rrs.getLastAnsType() != ResourceRecord.TYPE_SOA) {
|
|
// The response is split into multiple DNS messages.
|
|
do {
|
|
msg = continueTcpQuery(tcp);
|
|
if (msg == null) {
|
|
throw new CommunicationException(
|
|
"DNS error: incomplete zone transfer");
|
|
}
|
|
hdr = new Header(msg, msg.length);
|
|
checkResponseCode(hdr);
|
|
rrs.add(msg, msg.length, hdr);
|
|
} while (rrs.getLastAnsType() !=
|
|
ResourceRecord.TYPE_SOA);
|
|
}
|
|
|
|
// Delete the duplicate SOA record.
|
|
rrs.answer.removeElementAt(rrs.answer.size() - 1);
|
|
return rrs;
|
|
|
|
} finally {
|
|
tcp.close();
|
|
}
|
|
|
|
} catch (IOException e) {
|
|
caughtException = e;
|
|
} catch (NameNotFoundException e) {
|
|
throw e;
|
|
} catch (NamingException e) {
|
|
caughtException = e;
|
|
}
|
|
}
|
|
if (caughtException instanceof NamingException) {
|
|
throw (NamingException) caughtException;
|
|
}
|
|
NamingException ne = new CommunicationException(
|
|
"DNS error during zone transfer");
|
|
ne.setRootCause(caughtException);
|
|
throw ne;
|
|
}
|
|
|
|
|
|
/**
|
|
* Tries to retreive an UDP packet matching the given xid
|
|
* received within the timeout.
|
|
* If a packet with different xid is received, the received packet
|
|
* is enqueued with the corresponding xid in 'resps'.
|
|
*/
|
|
private byte[] doUdpQuery(Packet pkt, InetAddress server,
|
|
int port, int retry, int xid)
|
|
throws IOException, NamingException {
|
|
|
|
int minTimeout = 50; // msec after which there are no retries.
|
|
|
|
synchronized (udpSocketLock) {
|
|
try (DatagramSocket udpSocket = getDatagramSocket()) {
|
|
DatagramPacket opkt = new DatagramPacket(
|
|
pkt.getData(), pkt.length(), server, port);
|
|
DatagramPacket ipkt = new DatagramPacket(new byte[8000], 8000);
|
|
// Packets may only be sent to or received from this server address
|
|
udpSocket.connect(server, port);
|
|
int pktTimeout = (timeout * (1 << retry));
|
|
try {
|
|
udpSocket.send(opkt);
|
|
|
|
// timeout remaining after successive 'receive()'
|
|
int timeoutLeft = pktTimeout;
|
|
int cnt = 0;
|
|
do {
|
|
if (debug) {
|
|
cnt++;
|
|
dprint("Trying RECEIVE(" +
|
|
cnt + ") retry(" + (retry + 1) +
|
|
") for:" + xid + " sock-timeout:" +
|
|
timeoutLeft + " ms.");
|
|
}
|
|
udpSocket.setSoTimeout(timeoutLeft);
|
|
long start = System.currentTimeMillis();
|
|
udpSocket.receive(ipkt);
|
|
long end = System.currentTimeMillis();
|
|
|
|
byte[] data = ipkt.getData();
|
|
if (isMatchResponse(data, xid)) {
|
|
return data;
|
|
}
|
|
timeoutLeft = pktTimeout - ((int) (end - start));
|
|
} while (timeoutLeft > minTimeout);
|
|
|
|
} finally {
|
|
udpSocket.disconnect();
|
|
}
|
|
return null; // no matching packet received within the timeout
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Sends a TCP query, and returns the first DNS message in the response.
|
|
*/
|
|
private byte[] doTcpQuery(Tcp tcp, Packet pkt) throws IOException {
|
|
|
|
int len = pkt.length();
|
|
// Send 2-byte message length, then send message.
|
|
tcp.out.write(len >> 8);
|
|
tcp.out.write(len);
|
|
tcp.out.write(pkt.getData(), 0, len);
|
|
tcp.out.flush();
|
|
|
|
byte[] msg = continueTcpQuery(tcp);
|
|
if (msg == null) {
|
|
throw new IOException("DNS error: no response");
|
|
}
|
|
return msg;
|
|
}
|
|
|
|
/*
|
|
* Returns the next DNS message from the TCP socket, or null on EOF.
|
|
*/
|
|
private byte[] continueTcpQuery(Tcp tcp) throws IOException {
|
|
|
|
int lenHi = tcp.in.read(); // high-order byte of response length
|
|
if (lenHi == -1) {
|
|
return null; // EOF
|
|
}
|
|
int lenLo = tcp.in.read(); // low-order byte of response length
|
|
if (lenLo == -1) {
|
|
throw new IOException("Corrupted DNS response: bad length");
|
|
}
|
|
int len = (lenHi << 8) | lenLo;
|
|
byte[] msg = new byte[len];
|
|
int pos = 0; // next unfilled position in msg
|
|
while (len > 0) {
|
|
int n = tcp.in.read(msg, pos, len);
|
|
if (n == -1) {
|
|
throw new IOException(
|
|
"Corrupted DNS response: too little data");
|
|
}
|
|
len -= n;
|
|
pos += n;
|
|
}
|
|
return msg;
|
|
}
|
|
|
|
private Packet makeQueryPacket(DnsName fqdn, int xid,
|
|
int qclass, int qtype, boolean recursion) {
|
|
int qnameLen = fqdn.getOctets();
|
|
int pktLen = DNS_HDR_SIZE + qnameLen + 4;
|
|
Packet pkt = new Packet(pktLen);
|
|
|
|
short flags = recursion ? Header.RD_BIT : 0;
|
|
|
|
pkt.putShort(xid, IDENT_OFFSET);
|
|
pkt.putShort(flags, FLAGS_OFFSET);
|
|
pkt.putShort(1, NUMQ_OFFSET);
|
|
pkt.putShort(0, NUMANS_OFFSET);
|
|
pkt.putInt(0, NUMAUTH_OFFSET);
|
|
|
|
makeQueryName(fqdn, pkt, DNS_HDR_SIZE);
|
|
pkt.putShort(qtype, DNS_HDR_SIZE + qnameLen);
|
|
pkt.putShort(qclass, DNS_HDR_SIZE + qnameLen + 2);
|
|
|
|
return pkt;
|
|
}
|
|
|
|
// Builds a query name in pkt according to the RFC spec.
|
|
private void makeQueryName(DnsName fqdn, Packet pkt, int off) {
|
|
|
|
// Loop through labels, least-significant first.
|
|
for (int i = fqdn.size() - 1; i >= 0; i--) {
|
|
String label = fqdn.get(i);
|
|
int len = label.length();
|
|
|
|
pkt.putByte(len, off++);
|
|
for (int j = 0; j < len; j++) {
|
|
pkt.putByte(label.charAt(j), off++);
|
|
}
|
|
}
|
|
if (!fqdn.hasRootLabel()) {
|
|
pkt.putByte(0, off);
|
|
}
|
|
}
|
|
|
|
//-------------------------------------------------------------------------
|
|
|
|
private byte[] lookupResponse(Integer xid) throws NamingException {
|
|
//
|
|
// Check the queued responses: some other thread in between
|
|
// received the response for this request.
|
|
//
|
|
if (debug) {
|
|
dprint("LOOKUP for: " + xid +
|
|
"\tResponse Q:" + resps);
|
|
}
|
|
byte[] pkt;
|
|
if ((pkt = resps.get(xid)) != null) {
|
|
checkResponseCode(new Header(pkt, pkt.length));
|
|
synchronized (queuesLock) {
|
|
resps.remove(xid);
|
|
reqs.remove(xid);
|
|
}
|
|
|
|
if (debug) {
|
|
dprint("FOUND (" + Thread.currentThread() +
|
|
") for:" + xid);
|
|
}
|
|
}
|
|
return pkt;
|
|
}
|
|
|
|
/*
|
|
* Checks the header of an incoming DNS response.
|
|
* Returns true if it matches the given xid and throws a naming
|
|
* exception, if appropriate, based on the response code.
|
|
*
|
|
* Also checks that the domain name, type and class in the response
|
|
* match those in the original query.
|
|
*/
|
|
private boolean isMatchResponse(byte[] pkt, int xid)
|
|
throws NamingException {
|
|
|
|
Header hdr = new Header(pkt, pkt.length);
|
|
if (hdr.query) {
|
|
throw new CommunicationException("DNS error: expecting response");
|
|
}
|
|
|
|
if (!reqs.containsKey(xid)) { // already received, ignore the response
|
|
return false;
|
|
}
|
|
|
|
// common case- the request sent matches the subsequent response read
|
|
if (hdr.xid == xid) {
|
|
if (debug) {
|
|
dprint("XID MATCH:" + xid);
|
|
}
|
|
checkResponseCode(hdr);
|
|
if (!hdr.query && hdr.numQuestions == 1) {
|
|
|
|
ResourceRecord rr = new ResourceRecord(pkt, pkt.length,
|
|
Header.HEADER_SIZE, true, false);
|
|
|
|
// Retrieve the original query
|
|
ResourceRecord query = reqs.get(xid);
|
|
int qtype = query.getType();
|
|
int qclass = query.getRrclass();
|
|
DnsName qname = query.getName();
|
|
|
|
// Check that the type/class/name in the query section of the
|
|
// response match those in the original query
|
|
if ((qtype == ResourceRecord.QTYPE_STAR ||
|
|
qtype == rr.getType()) &&
|
|
(qclass == ResourceRecord.QCLASS_STAR ||
|
|
qclass == rr.getRrclass()) &&
|
|
qname.equals(rr.getName())) {
|
|
|
|
if (debug) {
|
|
dprint("MATCH NAME:" + qname + " QTYPE:" + qtype +
|
|
" QCLASS:" + qclass);
|
|
}
|
|
|
|
// Remove the response for the xid if received by some other
|
|
// thread.
|
|
synchronized (queuesLock) {
|
|
resps.remove(xid);
|
|
reqs.remove(xid);
|
|
}
|
|
return true;
|
|
|
|
} else {
|
|
if (debug) {
|
|
dprint("NO-MATCH NAME:" + qname + " QTYPE:" + qtype +
|
|
" QCLASS:" + qclass);
|
|
}
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
//
|
|
// xid mis-match: enqueue the response, it may belong to some other
|
|
// thread that has not yet had a chance to read its response.
|
|
// enqueue only the first response, responses for retries are ignored.
|
|
//
|
|
synchronized (queuesLock) {
|
|
if (reqs.containsKey(hdr.xid)) { // enqueue only the first response
|
|
resps.put(hdr.xid, pkt);
|
|
}
|
|
}
|
|
|
|
if (debug) {
|
|
dprint("NO-MATCH SEND ID:" +
|
|
xid + " RECVD ID:" + hdr.xid +
|
|
" Response Q:" + resps +
|
|
" Reqs size:" + reqs.size());
|
|
}
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* Throws an exception if appropriate for the response code of a
|
|
* given header.
|
|
*/
|
|
private void checkResponseCode(Header hdr) throws NamingException {
|
|
|
|
int rcode = hdr.rcode;
|
|
if (rcode == NO_ERROR) {
|
|
return;
|
|
}
|
|
String msg = (rcode < rcodeDescription.length)
|
|
? rcodeDescription[rcode]
|
|
: "DNS error";
|
|
msg += " [response code " + rcode + "]";
|
|
|
|
switch (rcode) {
|
|
case SERVER_FAILURE:
|
|
throw new ServiceUnavailableException(msg);
|
|
case NAME_ERROR:
|
|
throw new NameNotFoundException(msg);
|
|
case NOT_IMPL:
|
|
case REFUSED:
|
|
throw new OperationNotSupportedException(msg);
|
|
case FORMAT_ERROR:
|
|
default:
|
|
throw new NamingException(msg);
|
|
}
|
|
}
|
|
|
|
//-------------------------------------------------------------------------
|
|
|
|
private static final boolean debug = false;
|
|
|
|
private static void dprint(String mess) {
|
|
if (debug) {
|
|
System.err.println("DNS: " + mess);
|
|
}
|
|
}
|
|
|
|
}
|
|
|
|
class Tcp {
|
|
|
|
private Socket sock;
|
|
java.io.InputStream in;
|
|
java.io.OutputStream out;
|
|
|
|
Tcp(InetAddress server, int port) throws IOException {
|
|
sock = new Socket(server, port);
|
|
sock.setTcpNoDelay(true);
|
|
out = new java.io.BufferedOutputStream(sock.getOutputStream());
|
|
in = new java.io.BufferedInputStream(sock.getInputStream());
|
|
}
|
|
|
|
void close() throws IOException {
|
|
sock.close();
|
|
}
|
|
}
|
|
|
|
/*
|
|
* javaos emulation -cj
|
|
*/
|
|
class Packet {
|
|
byte buf[];
|
|
|
|
Packet(int len) {
|
|
buf = new byte[len];
|
|
}
|
|
|
|
Packet(byte data[], int len) {
|
|
buf = new byte[len];
|
|
System.arraycopy(data, 0, buf, 0, len);
|
|
}
|
|
|
|
void putInt(int x, int off) {
|
|
buf[off + 0] = (byte)(x >> 24);
|
|
buf[off + 1] = (byte)(x >> 16);
|
|
buf[off + 2] = (byte)(x >> 8);
|
|
buf[off + 3] = (byte)x;
|
|
}
|
|
|
|
void putShort(int x, int off) {
|
|
buf[off + 0] = (byte)(x >> 8);
|
|
buf[off + 1] = (byte)x;
|
|
}
|
|
|
|
void putByte(int x, int off) {
|
|
buf[off] = (byte)x;
|
|
}
|
|
|
|
void putBytes(byte src[], int src_offset, int dst_offset, int len) {
|
|
System.arraycopy(src, src_offset, buf, dst_offset, len);
|
|
}
|
|
|
|
int length() {
|
|
return buf.length;
|
|
}
|
|
|
|
byte[] getData() {
|
|
return buf;
|
|
}
|
|
}
|