RFR - 8159410: InetAddress.isReachable returns true for non existing IP addresses

[Rob McKenna]

I've updated the webrev here with the copyright year (thanks Christoph) and extra error codes. I overlooked the codes from the old implementation of tcp_ping4 above this code. These are winsock error codes which I would expect IcmpSendEcho to use, but in our testing it actually returned the system error codes in at least one situation:

https://msdn.microsoft.com/en-gb/library/windows/desktop/ms740668%28v=vs.85%29.aspx
https://msdn.microsoft.com/en-us/library/windows/desktop/ms681383%28v=vs.85%29.aspx

	-Rob

On 21/09/16 06:32, Seán Coffey wrote:
> spotted an interesting blog on the MSDN timeout issue here :
> https://www.frameflow.com/ping-utility-flaw-in-windows-api-creating-false-timeouts/
> 
> Regards,
> Sean.
> 
> On 21/09/16 17:42, Mark Sheppard wrote:
> >
> >the IcmpSendEcho series of calls come with some idiosyncrasies in that
> >there is a minimum timeout that they can handle
> >think it is about 1000msecs. isReachable can specify a finer grained
> >timeout hence the need for timeout check
> >
> >regards
> >Mark
> >
> >On 21/09/2016 17:18, Vyom Tewari wrote:
> >>
> >>Hi Rob,
> >>
> >>Do you really think this extra check is required ?
> >>
> >>if (pEchoReply->Status == IP_SUCCESS
> >>+ && (int)pEchoReply->RoundTripTime <= timeout) I did not found any
> >>doc(MSDN) which explains this. I think in case of IP_SUCCESS
> >>"RoundTripTime" is always less than timeout. I think similar changes is
> >>required in Inet6Address.c as well ? Thanks, Vyom
> >>
> >>On Wednesday 21 September 2016 08:46 PM, Rob McKenna wrote:
> >>>Hi folks,
> >>>
> >>>I'd like to fix a bug caused by an incorrect assumption. The IcmpSendEcho* calls can actually return a similar set of errors regardless of whether the call itself failed or succeeded. This change checks that both the call and the ping were successful. In addition to that it takes a number of common failure causes into account before deciding to throw an exception.
> >>>
> >>>http://cr.openjdk.java.net/~robm/8159410/webrev.01/
> >>>
> >>>	-Rob
> >>
> >
>