RFR: JDK-6458027 - Disabling IPv6 on a specific network interface causes problems

[Michael McMahon]

One comment so far. The ipv4mode parameter in

getIPv4NetworkInterface()

seems superfluous, with the call using parameter value "0"
could be just elided to using the null return value directly.

I was a bit confused also that the new function is in the TwoStacks... 
module,
but it seems this file contains native code common to both dual 
stack/two stacks
mode. We probably should move this code to a different source file some 
time,
but it might be useful to put a comment in at least to say that it is 
common
to both modes.

Michael



On 15/09/13 12:34, Mark Sheppard wrote:
> Hi
>    please oblige and review the webrev below which addresses the issue
>
> problem:
> https://bugs.openjdk.java.net/browse/JDK-6458027
>
> webrev:
> http://cr.openjdk.java.net/~msheppar/6458027/webrev/
>
> the core of the issue is that a windows platform may be IPv6 enabled, but
> an individual adapter/interface may not be configured with for IPv6.
> This causes a problem with the MulticastSocket.setNetworkInterface()
> and MulticastSocket.getNetworkInterface() methods.
>
> The solution focuses on adding and additional check on the
> individual interface for IPV6 enabling.
>
> The fallback position when an adapter is not configured for IPV6, is to
> handled it as IPV4, only.
>
> It should be noted that setting an Interface which does not have a
> valid IP address bound to it will result in a SocketException. As such, i
> the onus in on the application to supply a validly configured
> NetworkInterface object to the MulticastSocket.setNetworkInterface().
>
> With this in mind, the set of Interfaces constructed for the 
> associated test
> is based on the interface being up, multicast, and valid IP address
> configured.
>
> regards
> Mark