RFR (S): JDK-8250630 JdwpListenTest.java fails on Alpine Linux

[Dmitry Samersoff]

Hello Everybody,

http://cr.openjdk.java.net/~dsamersoff/JDK-8250630/webrev.02/

Webrev is updated, all comments accepted and addressed.

Except:
 > The error code from the inet_pton is not checked.

inet_pton performs conversion of the constant value in our case and the 
only possible reason for it to fail is that the system doesn't support 
IPv6 at all.

-Dmitry


On 18.08.2020 3:20, serguei.spitsyn at oracle.com wrote:
> Hi Dmitry,
> 
> I agree with Alex, it is better to rename compareIPv6Addr to 
> isEqualIPv6Addr.
> 
> 705 static int compareIPv6Addr(struct addrinfo *ai, struct in6_addr in6Addr)
> 706 {
> 707
> 708 if (ai->ai_addr->sa_family == AF_INET6) {
> 709 const struct sockaddr_in6 sa = *((struct sockaddr_in6*) ai->ai_addr);
> 710 return (memcmp(&sa.sin6_addr, &in6Addr, sizeof(in6Addr)) == 0);
> 711 }
> 712
> 713 return 0;
> 714 }
> 
> I think, the lines 707 and 712 are not needed.
> 
> 725 struct in6_addr mappedAny; ... 761 inet_pton(AF_INET6, 
> "::ffff:0.0.0.0", &mappedAny);
> 
> The error code from the inet_pton is not checked.
> Also, it can be useful to pre-initialize the mappedAny.
> 
> 737 // Try to find bind address of preferred address familty first A dot 
> at the end of comment is missed.
> 
> 745 if (listenAddr == NULL) {
> 746 // No address of preferred addres family found, grab the first one
> 747 listenAddr = &(addrInfo[0]);
>   748     }
> 
> The indent has to be 4, not 3.
> The () brackets are not actually needed but I do not object if you keep 
> them.
> A dot at the end of comment is missed.
> 
> 755 // Binding to IN6ADDR_ANY allow us to serve both IPv4 and IPv6 
> connections,
> 756 // but binding to mapped INADDR_ANY (::ffff:0.0.0.0) allow us to 
> serve IPv4
> 757 // connections only. So make sure, that IN6ADDR_ANY is preferred over
> 758 // mapped INADDR_ANY if preferredAddressFamily is AF_INET6 or not set
> 
> I'd suggest to replace "allow us" => "allows" in two places:
>    "IN6ADDR_ANY allow us" and "(::ffff:0.0.0.0) allow us".
> Also, it'd better to replace: "So make sure,that" => "Make sure that".
> A dot at the end of comment is missed.
> 
> I don't know the network protocols well enough to comment on
> 
> 
> Thanks,
> Serguei
> 
> 
> On 8/17/20 00:21, Dmitry Samersoff wrote:
>> Hello Everybody,
>>
>> Please review the fix:
>>
>> https://cr.openjdk.java.net/~dsamersoff/JDK-8250630/webrev.01/
>>
>> Binding to IN6ADDR_ANY allow us to serve both IPv4 and IPv6 
>> connections, but binding to mapped INADDR_ANY (::ffff:0.0.0.0) allow 
>> us to serve IPv4 connections only.
>>
>> So make sure, that IN6ADDR_ANY is preferred over mapped INADDR_ANY if 
>> preferredAddressFamily is not AF_INET
>>
>>
>> -Dmitry\S
>>
>