1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
|
/*
* 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;
import static java.util.concurrent.TimeUnit.NANOSECONDS;
import static jdk.test.lib.Utils.adjustTimeout;
/*
* @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
* @run main TcpTimeout -Dcom.sun.jndi.dns.timeout.initial=5000
*/
public class TcpTimeout extends DNSTestBase {
private TcpDnsServer tcpDnsServer;
/* The acceptable variation in timeout measurement. */
private static final long TOLERANCE = adjustTimeout(5_000);
/* The acceptable variation of early returns from timed socket operations. */
private static final long PREMATURE_RETURN = adjustTimeout(100);
public static void main(String[] args) throws Exception {
new TcpTimeout().run(args);
}
@Override
public void runTest() throws Exception {
/* The default timeout value is 1 second, as stated in the
jdk.naming.dns module docs. */
long timeout = 1_000;
var envTimeout = env().get("com.sun.jndi.dns.timeout.initial");
if (envTimeout != null)
timeout = Long.parseLong(String.valueOf(envTimeout));
setContext(new InitialDirContext(env()));
long startNanos = System.nanoTime();
/* perform query */
var attrs = context().getAttributes("host1");
long elapsed = NANOSECONDS.toMillis(System.nanoTime() - startNanos);
if (elapsed < timeout - PREMATURE_RETURN || elapsed > timeout + TOLERANCE) {
throw new RuntimeException(String.format(
"elapsed=%s, timeout=%s, TOLERANCE=%s, PREMATURE_RETURN=%s",
elapsed, timeout, TOLERANCE, PREMATURE_RETURN));
}
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 ignored) { }
}
}
}
|
