1 /*
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3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4  *
5  * This code is free software; you can redistribute it and/or modify it
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7  * published by the Free Software Foundation.
8  *
9  * This code is distributed in the hope that it will be useful, but WITHOUT
10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12  * version 2 for more details (a copy is included in the LICENSE file that
13  * accompanied this code).
14  *
15  * You should have received a copy of the GNU General Public License version
16  * 2 along with this work; if not, write to the Free Software Foundation,
17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18  *
19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20  * or visit www.oracle.com if you need additional information or have any
21  * questions.
22  */
23 
24 /*
25  * @test
26  * @bug 4686717
27  * @summary Test MulticastSocket.setLoopbackMode
28  * @library /test/lib
29  * @build jdk.test.lib.NetworkConfiguration
30  *        jdk.test.lib.Platform
31  * @run main/othervm SetLoopbackMode
32  */
33 
34 import java.net.*;
35 import java.io.IOException;
36 import java.util.Enumeration;
37 import jdk.test.lib.NetworkConfiguration;
38 
39 public class SetLoopbackMode {
40 
41     static final boolean FAILED = true;
42     static final boolean PASSED = false;
43 
test(MulticastSocket mc, InetAddress grp)44     static boolean test(MulticastSocket mc, InetAddress grp) throws IOException {
45 
46         boolean disabled = mc.getLoopbackMode();
47 
48         if (disabled) {
49             System.out.println("Loopback mode is disabled.");
50         } else {
51             System.out.println("Loopback mode is enabled.");
52         }
53 
54         byte b[] = "hello".getBytes();
55         DatagramPacket p = new DatagramPacket(b, b.length, grp,
56                                 mc.getLocalPort());
57         mc.send(p);
58 
59         boolean gotPacket = false;
60 
61         mc.setSoTimeout(1000);
62         try {
63             b = new byte[16];
64             p = new DatagramPacket(b, b.length);
65             mc.receive(p);
66             gotPacket = true;
67 
68             /* purge any additional copies of the packet */
69             for (;;) {
70                 mc.receive(p);
71             }
72 
73         } catch (SocketTimeoutException x) {
74         }
75 
76         if (gotPacket && disabled) {
77             System.out.println("Packet received (unexpected as loopback is disabled)");
78             return FAILED;
79         }
80         if (!gotPacket && !disabled) {
81             System.out.println
82                 ("Packet not received (packet excepted as loopback is enabled)");
83             return FAILED;
84         }
85 
86         if (gotPacket && !disabled) {
87             System.out.println("Packet received - correct.");
88         } else {
89             System.out.println("Packet not received - correct.");
90         }
91 
92         return PASSED;
93     }
94 
canUseIPv6(NetworkConfiguration nc)95     private static boolean canUseIPv6(NetworkConfiguration nc) {
96         return nc.ip6MulticastInterfaces().toArray().length > 0;
97     }
98 
main(String args[])99     public static void main (String args[]) throws Exception {
100         int failures = 0;
101         NetworkConfiguration nc = NetworkConfiguration.probe();
102 
103         MulticastSocket mc = new MulticastSocket();
104         InetAddress grp = InetAddress.getByName("224.80.80.80");
105 
106 
107         /*
108          * If IPv6 is available then use IPv6 multicast group - needed
109          * to workaround Linux IPv6 bug whereby !IPV6_MULTICAST_LOOP
110          * doesn't prevent loopback of IPv4 multicast packets.
111          */
112 
113         if (canUseIPv6(nc)) {
114             grp = InetAddress.getByName("ff01::1");
115         }
116 
117         //mc.setNetworkInterface(NetworkInterface.getByInetAddress(lb));
118         System.out.println("\nTest will use multicast group: " + grp);
119         mc.joinGroup(grp);
120 
121         System.out.println("\n******************\n");
122 
123         mc.setLoopbackMode(true);
124         if (test(mc, grp) == FAILED) failures++;
125 
126         System.out.println("\n******************\n");
127 
128         mc.setLoopbackMode(false);
129         if (test(mc, grp) == FAILED) failures++;
130 
131         System.out.println("\n******************\n");
132 
133         if (failures > 0) {
134             throw new RuntimeException("Test failed");
135         }
136     }
137 }
138