RFR - 8159410: InetAddress.isReachable returns true for non existing IP addresses
rob.mckenna at oracle.com
Wed Sep 21 18:07:00 UTC 2016
Yup. To elabourate:
If we set a small timeout for a faraway host with a high ping, IcmpSendEcho can report success even if the rtt exceeded the timeout, hence the need for this explicit check.
On 21/09/16 11:07, Vyom Tewari wrote:
> So InetAddress.isReachable() will return false if the underline API
> IcmpSendEcho return with Status== IP_SUCESS and RoundTripTime > timeout.
> On Wednesday 21 September 2016 10:39 PM, Rob McKenna wrote:
> >Unfortunately the behaviour described is undocumented and was found the hard way. This part of the code is a necessity though.
> > -Rob
> >On 21/09/16 09:48, 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.
> >>> -Rob
More information about the net-dev