8158519: Incorrect network mask and broadcast address on Linux when there are multiple IPv4 addresses on an interface

[Langer, Christoph]

Hi Chris,

I had already created a bug report for this: https://bugs.openjdk.java.net/browse/JDK-8158170 in the meanwhile but unfortunately, by mistake, I had just sent this information to Doychin and not to the mailing list. So, feel free to close and mark my bug as duplicate.

I also started work on testing Doychin's approach but did not yet find time to finish it - so you overtook me on that one also.

As for AIX, there is no getifaddrs available. So there we have to stick to the ioctl approach.

I'll take a deeper look next week.

Best regards
Christoph

> -----Original Message-----
> From: net-dev [mailto:net-dev-bounces at openjdk.java.net] On Behalf Of Chris
> Hegarty
> Sent: Donnerstag, 2. Juni 2016 14:06
> To: Doychin Bondzhev <doychin at dsoft-bg.com>; OpenJDK Network Dev list
> <net-dev at openjdk.java.net>
> Subject: 8158519: Incorrect network mask and broadcast address on Linux
> when there are multiple IPv4 addresses on an interface
> 
> Doychin, et al,
> 
> I finally got time to look at the issue you reported and your suggested patch. I
> filed
> 8158519 [1] to track the issue. I think your suggested patch may be ok, but I just
> wanted to push on the ioctl approach. I found an alternative, and verified that it
> works as expected. Please take a look, and verify in your environment.  Then
> we
> need to weigh up the two separate approaches.
> 
> http://cr.openjdk.java.net/~chegar/8158519.00/
> 
> For the record, I don’t have any specific issue with using getifaddrs, I just
> wanted to
> see if there was a less invasive change. That said, using getifaddrs could lead to
> cleaner code, but we would need to check the situation on AIX ( which I don’t
> have
> access to ).
> 
> -Chris.
> 
> [1] https://bugs.openjdk.java.net/browse/JDK-8158519