RFR: JDK-8057556: JDP should better handle non-active interfaces

[Yasumasa Suenaga]

Hi Peter,

I fixed it and created new webrev.
http://cr.openjdk.java.net/~ysuenaga/JDK-8057556/webrev.1/

Could you review it again?


Thanks,

Yasumasa


(2014/09/05 17:20), Peter Allwin wrote:
> Looks like only the first Interface will be considered if no srcAddress is provided (succeeded will be false and we will throw to exit the while loop). Is this intended?
>
> Thanks!
> /peter
>
>> On 4 sep 2014, at 17:59, Yasumasa Suenaga <yasuenag at gmail.com> wrote:
>>
>> Hi all,
>>
>> Thank you so much, Dmitry!
>>
>> I've created webrev for it.
>> http://cr.openjdk.java.net/~ysuenaga/JDK-8057556/webrev.0/
>>
>> Please review.
>>
>>
>> Thanks,
>>
>> Yasumasa
>>
>>
>> (2014/09/04 21:26), Dmitry Samersoff wrote:
>>> Yasumasa,
>>>
>>> The CR number is JDK-8057556
>>>
>>> I'll care about it's integration.
>>>
>>> -Dmitry
>>>
>>>> On 2014-09-02 18:52, Yasumasa Suenaga wrote:
>>>> Hi all,
>>>>
>>>> I'm trying to use JDP on my Fedora20 machine.
>>>> My machine has two NICs and only one NIC is up.
>>>>
>>>> I passed system properties as below, however JDP broadcaster
>>>> thread was not started:
>>>>
>>>>    -Dcom.sun.management.jmxremote.port=7091
>>>>    -Dcom.sun.management.jmxremote.authenticate=false
>>>>    -Dcom.sun.management.jmxremote.ssl=false
>>>>    -Dcom.sun.management.jmxremote.autodiscovery=true
>>>>    -Dcom.sun.management.jdp.name=TEST
>>>>
>>>> I checked exceptions with jdb, SocketException was occurred in
>>>> JDPControllerRunner#run(), and it was caused by another NIC
>>>> is down.
>>>>
>>>> Currently, DiagramChannel which is used in JDPBroadcaster
>>>> tries to send JDP packet through all "UP" NICs.
>>>> However, NIC which is controlled by NetworkManager seems to
>>>> be still "UP" when ifdown command is executed.
>>>> (It seems to be removed IP address from NIC only.)
>>>>
>>>>
>>>> This problem may be Fedora, however I think it should be
>>>> improved in JDK.
>>>> I've created a patch as below, and it works fine in my environment.
>>>> (jdk9/dev/jdk)
>>>>
>>>> If this patch may be accepted, I will file this to JBS.
>>>>
>>>> --------------------
>>>> diff -r 68a6bb51cb26 src/java.management/share/classes/sun/management/jdp/JdpBroadcaster.java
>>>> --- a/src/java.management/share/classes/sun/management/jdp/JdpBroadcaster.java    Mon Sep 01 13:33:28 2014 +0200
>>>> +++ b/src/java.management/share/classes/sun/management/jdp/JdpBroadcaster.java    Tue Sep 02 23:25:50 2014 +0900
>>>> @@ -35,6 +35,7 @@
>>>>   import java.nio.ByteBuffer;
>>>>   import java.nio.channels.DatagramChannel;
>>>>   import java.nio.channels.UnsupportedAddressTypeException;
>>>> +import java.util.Enumeration;
>>>>
>>>>   /**
>>>>    * JdpBroadcaster is responsible for sending pre-built JDP packet across a Net
>>>> @@ -79,6 +80,15 @@
>>>>           if (srcAddress != null) {
>>>>               // User requests particular interface to bind to
>>>>               NetworkInterface interf = NetworkInterface.getByInetAddress(srcAddress);
>>>> +
>>>> +            if (interf == null) {
>>>> +                throw new JdpException("Unable to get network interface for " + srcAddress.toString());
>>>> +            }
>>>> +
>>>> +            if (!interf.isUp() || !interf.supportsMulticast()) {
>>>> +                throw new JdpException(interf.getName() + " does not support multicast.");
>>>> +            }
>>>> +
>>>>               try {
>>>>                   channel.bind(new InetSocketAddress(srcAddress, 0));
>>>>               } catch (UnsupportedAddressTypeException ex) {
>>>> @@ -86,6 +96,23 @@
>>>>               }
>>>>               channel.setOption(StandardSocketOptions.IP_MULTICAST_IF, interf);
>>>>           }
>>>> +        else {
>>>> +            Enumeration<NetworkInterface> nics = NetworkInterface.getNetworkInterfaces();
>>>> +            while (nics.hasMoreElements()) {
>>>> +                NetworkInterface nic = nics.nextElement();
>>>> +
>>>> +                if (nic.isUp() && nic.supportsMulticast()) {
>>>> +                    try {
>>>> +                        channel.setOption(StandardSocketOptions.IP_MULTICAST_IF, nic);
>>>> +                    } catch (IOException ex) {
>>>> +                        System.err.println("WARNING: JDP broadcaster cannot use " + nic.getName() + ": " + ex.getMessage());
>>>> +                    }
>>>> +                }
>>>> +
>>>> +            }
>>>> +
>>>> +        }
>>>> +
>>>>       }
>>>>
>>>>       /**
>>>> --------------------
>>>>
>>>>
>>>> Thanks,
>>>>
>>>> Yasumasa
>>>
>>>