Ping: RFR: JDK-8249550: jdb should use loopback address when not using remote agent

[serguei.spitsyn at oracle.com]

Hi Alex,

Thank you, for explanation.
Serguei


On 8/5/20 14:08, Alex Menkov wrote:
> Hi Serguei,
>
> Original issue is about jdb with CommandLineLaunch connector on 
> non-Windows systems tries to resolve hostname and start to listening 
> on it.
> This behavior can cause error (this is what the bug about) and does 
> not makes sense and CommandLineLaunch connector launches local 
> process, so there is no sense to listen for connections from other hosts.
>
> SocketTransportService is also used for jdb "listen" and "listenany" 
> commands, but this commands require address to be specified, so 
> startListening(String) is called, not startListening().
>
> So the only behavior change is a debuggee started by CommandLineLaunch 
> connector accepts debuggers only from local machine, but this is how 
> jdb works (it starts local process and connects to it).
> I don't think this requires CSR.
>
> --alex
>
> On 08/04/2020 17:22, serguei.spitsyn at oracle.com wrote:
>> Hi Alex,
>>
>> This looks good to me.
>> But do we need a CSR for this?
>> I understand that the intention is to comply with the 
>> TransportService spec but the behavior is being changed.
>> How long did we have this behavior?
>>
>> Thanks,
>> Serguei
>>
>>
>> On 8/4/20 16:32, Alex Menkov wrote:
>>> Needs one more reviewer.
>>>
>>> One more details to simplify review.
>>> SocketTransportService extends TransportService and spec for 
>>> TransportService.startListening() is:
>>>
>>>     /**
>>>      * Listens on an address chosen by the transport service.
>>>      *
>>>      * <p> This convenience method works as if by invoking
>>>      * {@link #startListening(String) startListening(null)}.
>>>      *
>>>      * @return  a listen key to be used in subsequent calls to be
>>>      *          {@link #accept accept} or {@link #stopListening
>>>      *          stopListening} methods.
>>>      *
>>>      * @throws  IOException
>>>      *          If an I/O error occurs.
>>>      */
>>>     public abstract ListenKey startListening() throws IOException;
>>>
>>> I.e. the fix updates SocketTransportService  to comply the spec.
>>>
>>> --alex
>>>
>>> On 07/23/2020 13:05, Chris Plummer wrote:
>>>> Hi Alex,
>>>>
>>>> I'm no expert in this area, but the changes appear to do what you 
>>>> describe (use the loopback address), so thumbs up.
>>>>
>>>> thanks,
>>>>
>>>> Chris
>>>>
>>>> On 7/21/20 3:04 PM, Alex Menkov wrote:
>>>>> Hi all,
>>>>>
>>>>> please review the fix for
>>>>> https://bugs.openjdk.java.net/browse/JDK-8249550
>>>>>
>>>>> webrev:
>>>>> http://cr.openjdk.java.net/~amenkov/jdk16/jdb_loopback/webrev/
>>>>>
>>>>> some background:
>>>>> https://bugs.openjdk.java.net/browse/JDK-8041435 made default 
>>>>> listening on loopback address.
>>>>> Later https://bugs.openjdk.java.net/browse/JDK-8184770 added 
>>>>> handling of "*" address to listen on all addresses, but it didn't 
>>>>> fixed "default" startListening() method (used by jdb through 
>>>>> SunCommandLineLauncher).
>>>>>
>>>>> The method called startListening(String localaddress, int port) 
>>>>> with localaddress == null, but this method for null localladdress 
>>>>> starts listening on all addresses (i.e. handle null value as "*").
>>>>> The fix changes it to startListening(String address) which handles 
>>>>> null address the same way as JDI socket connector does (i.e. 
>>>>> listens on loopback address only)
>>>>>
>>>>> --alex
>>>>
>>