The following JNDI environment properties may be used when creating + * the initial context. + * + *
These properties are used to alter the timeout-related defaults that the + * DNS provider uses when submitting queries. The DNS provider submits queries + * using the following exponential backoff algorithm. The provider submits a + * query to a DNS server and waits for a response to arrive within a timeout + * period (1 second by default). If it receives no response within the timeout + * period, it queries the next server, and so on. If the provider receives no + * response from any server, it doubles the timeout period and repeats the + * process of submitting the query to each server, up to a maximum number of + * retries (4 by default). + * + *
The {@code com.sun.jndi.dns.timeout.initial} property, if set, specifies + * the number of milliseconds to use as the initial timeout period (i.e., before + * any doubling). If this property has not been set, the default initial timeout + * is 1000 milliseconds. + * + *
The {@code com.sun.jndi.dns.timeout.retries} property, if set, specifies + * the number of times to retry each server using the exponential backoff + * algorithm described previously. If this property has not been set, the + * default number of retries is 4. + * * @provides javax.naming.spi.InitialContextFactory + * * @moduleGraph * @since 9 */ --- /dev/null 2019-09-13 11:17:07.000000000 +0100 +++ new/test/jdk/com/sun/jndi/dns/ConfigTests/TcpTimeout.dns 2019-09-13 11:17:07.000000000 +0100 @@ -0,0 +1,45 @@ +# +# Copyright (c) 2019, 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. +# +# 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. +# + +################################################################################ +# Capture file for TcpTimeout.java +# +# NOTE: This hexadecimal dump of DNS protocol messages was generated by +# running the GetEnv application program against a real DNS +# server along with DNSTracer +# +################################################################################ + +# DNS Request + +0000: 32 72 01 00 00 01 00 00 00 00 00 00 05 68 6F 73 2r...........hos +0010: 74 31 07 64 6F 6D 61 69 6E 31 03 63 6F 6D 00 00 t1.domain1.com.. +0020: FF 00 FF ... + + +# DNS Response + +0000: 32 72 82 00 00 01 00 06 00 01 00 01 05 68 6F 73 2r...........hos +0010: 74 31 07 64 6F 6D 61 69 6E 31 03 63 6F 6D 00 00 t1.domain1.com.. +0020: FF 00 01 C0 0C 00 10 00 01 00 00 8C A0 00 15 14 ................ +0030: 41 20 76 65 72 79 20 70 6F 70 75 6C 61 72 20 68 A very popular h --- /dev/null 2019-09-13 11:17:08.000000000 +0100 +++ new/test/jdk/com/sun/jndi/dns/ConfigTests/TcpTimeout.java 2019-09-13 11:17:08.000000000 +0100 @@ -0,0 +1,128 @@ +/* + * Copyright (c) 2019, 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. + * + * 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. + */ + +import jtreg.SkippedException; + +import javax.naming.directory.InitialDirContext; + +import java.io.IOException; +import java.net.BindException; +import java.net.InetAddress; +import java.net.ServerSocket; + +/* + * @test + * @bug 8228580 + * @summary Tests that we get a DNS response when the UDP DNS server returns a + * truncated response and the TCP DNS server does not respond at all + * after connect. + * @library ../lib/ + * @library /test/lib + * @modules java.base/sun.security.util + * @run main TcpTimeout + */ + +public class TcpTimeout extends DNSTestBase { + private TcpDnsServer tcpDnsServer; + + public static void main(String[] args) throws Exception { + new TcpTimeout().run(args); + } + + @Override + public void runTest() throws Exception { + /* Using the default context because we rely on the default DNS client + timeout setting, com.sun.jndi.dns.timeout.initial (which is currently 1000) */ + setContext(new InitialDirContext(env())); + + /* perform query */ + var attrs = context().getAttributes("host1"); + DNSTestUtils.debug(attrs); + + /* Note that the returned attributes are truncated and the response + is not valid. */ + var txtAttr = attrs.get("TXT"); + if (txtAttr == null) + throw new RuntimeException("TXT attribute missing."); + } + + @Override + public void initTest(String[] args) { + /* We need to bind the TCP server on the same port the UDP server is + listening to. This may not be possible if that port is in use. Retry + MAX_RETRIES times relying on UDP port randomness. */ + final int MAX_RETRIES = 5; + for (int i = 0; i < MAX_RETRIES; i++) { + super.initTest(args); + var udpServer = (Server) env().get(DNSTestUtils.TEST_DNS_SERVER_THREAD); + int port = udpServer.getPort(); + try { + tcpDnsServer = new TcpDnsServer(port); + break; // success + } catch (BindException be) { + DNSTestUtils.debug("Failed to bind server socket on port " + port + + ", retry no. " + (i + 1) + ", " + be.getMessage()); + } catch (Exception ex) { + throw new RuntimeException("Unexpected exception during initTest", ex); + } finally { + if (tcpDnsServer == null) { // cleanup behind exceptions + super.cleanupTest(); + } + } + } + + if (tcpDnsServer == null) { + throw new SkippedException("Cannot start TCP server after " + + MAX_RETRIES + + " tries, skip the test"); + } + } + + @Override + public void cleanupTest() { + super.cleanupTest(); + if (tcpDnsServer != null) + tcpDnsServer.stopServer(); + } + + /** + * A TCP server that accepts a connection and does nothing else: causes read + * timeout on client side. + */ + private static class TcpDnsServer { + final ServerSocket serverSocket; + + TcpDnsServer(int port) throws IOException { + serverSocket = new ServerSocket(port, 0, InetAddress.getLoopbackAddress()); + System.out.println("TcpDnsServer: listening on port " + port); + } + + void stopServer() { + try { + if (serverSocket != null) + serverSocket.close(); + } + catch (Exception e) {} + } + } +}