Re: "Permission denied" using socket with IPv6

[Michael McMahon]

Sounds like a native configuration issue all right. The native
connect appears to be getting an EPERM which according to Linux manpage
could be caused b a local firewall rule

Michael

On 01/06/15 21:14, Bobby Bissett wrote:

Hi all,

Can someone tell me how to diagnose this issue? I can't create a connection to another node using IPv6 because of the error below -- a short app demonstrates the problem. Everything I've found online so far is aimed at using IPv4 instead, but that's not my goal. This is on a Centos 6.6 virtual machine.

--- begin ---
[root@TWO test]}> java -version
java version "1.7.0_79"
OpenJDK Runtime Environment (rhel-2.5.5.3.el6_6-x86_64 u79-b14)
OpenJDK 64-Bit Server VM (build 24.79-b02, mixed mode)
[root@TWO test]}>
[root@TWO test]}>
[root@TWO test]}> cat IPv6Test.java
import java.net.InetAddress;
import java.net.Socket;

public class IPv6Test {

    public static void main(String[] args) {
        try {

InetAddress ia = InetAddress.getByName("fe80::20c:29ff:fe98:9210");

            System.err.println("Opening socket for: " + ia);
            Socket socket = new Socket(ia, 7800);
            System.err.println("We have: " + socket);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}
[root@TWO test]}>
[root@TWO test]}> javac IPv6Test.java && java IPv6Test
Opening socket for: /fe80:0:0:0:20c:29ff:fe98:9210
java.net.SocketException: Permission denied
at java.net.PlainSocketImpl.socketConnect(Native Method)

at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:339) at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:200) at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:182)

at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
at java.net.Socket.connect(Socket.java:579)
at java.net.Socket.connect(Socket.java:528)
at java.net.Socket.<init>(Socket.java:425)
at java.net.Socket.<init>(Socket.java:241)
at IPv6Test.main(IPv6Test.java:10)
[root@TWO test]}>
[root@TWO test]}> java -version
java version "1.7.0_79"
OpenJDK Runtime Environment (rhel-2.5.5.3.el6_6-x86_64 u79-b14)
OpenJDK 64-Bit Server VM (build 24.79-b02, mixed mode)
--- end ---

From this node, am able to ping6 the address fine:

[root@TWO test]}> ping6 -I eth3 fe80::20c:29ff:fe98:9210

PING fe80::20c:29ff:fe98:9210(fe80::20c:29ff:fe98:9210) from fe80::20c:29ff:fec6:91a eth3: 56 data bytes

[...]
2 packets transmitted, 2 received, 0% packet loss, time 1023ms

I don't have selinux or a firewall running, not that I think that would matter since Java can't start to connect anyway from the message above.

Thanks,
Bobby