[ipv6] RFR: 8223737: HostsFileNameService doesn't handle IPv6 literal addresses correctly

[mark sheppard]

Hi Arthur, Chris,
   just a note in passing, as you are well set on the changes, which is all  good -- needs must, as they say.

The current implementation is an emulation of the gethostbyname and gethostbyaddr lookup on /etc/hosts.
The reverse lookup  issue is also solved by adding an additional entry in the hosts file
0:0:0:0:0:0:0:1 ip6-localhost ip6-loopback. Your reverse lookup will pass.

$ /cygdrive/c/Development/jdk-installs/jdk-12/bin/java InternalNameServiceWithHostsFileTest
############################  InetAddress == ip6-localhost/0:0:0:0:0:0:0:1​
retrieved address == [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1] equal to expected address == [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1]​
testReverseLookup: host addr ::1 : expected host name ip6-localhost​
testReverseLookup: host addr 0:0:0:0:0:0:0:1 : expected host name ip6-localhost​
testReverseLookup: host addr 0000:0000:0000:0000:0000:0000:0000:0001 : expected host name ip6-localhost​

That was the design -- the hosts file would contain whatever set of mapping are required for a particular context.
So the string comparison was sufficient.

IF your reverse lookup tests are run against the PlatformFormNameService,
which is the fall through to the native OS calls gethostbyname, getaddrinfo etc.
then you get the same set of failure afaik.

on windows using jdk12 test output shown below
so you could say there is some degree of consistent behaviour between the two services!!

regards
Mark



msheppard at MARKS-LAPTOP /cygdrive/c/Users/msheppard/eclipse-workspace/JDK-Tests
$ /cygdrive/c/Development/jdk-installs/jdk-12/bin/java  -Djava.net.preferIPv6Addresses=true PlatformNameServiceTest​
############################  InetAddress == localhost/0:0:0:0:0:0:0:1​
retrieved address == [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1] equal to expected address == [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1]​
testReverseLookup: host addr ::1 : expected host name localhost​
Exception in thread "main" java.lang.RuntimeException: reverse lookup of "::1" is "0:0:0:0:0:0:0:1", should be "localhost"​
​
        at PlatformNameServiceTest.testReverseLookup(PlatformNameServiceTest.java:64)​
        at PlatformNameServiceTest.main(PlatformNameServiceTest.java:25)​
​
msheppard at MARKS-LAPTOP /cygdrive/c/Users/msheppard/eclipse-workspace/JDK-Tests​
$ /cygdrive/c/Development/jdk-installs/jdk-12/bin/java  -Djava.net.preferIPv6Addresses=true PlatformNameServiceTest​
############################  InetAddress == localhost/0:0:0:0:0:0:0:1​
retrieved address == [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1] equal to expected address == [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1]​
testReverseLookup: host addr 0:0:0:0:0:0:0:1 : expected host name localhost​
Exception in thread "main" java.lang.RuntimeException: reverse lookup of "0:0:0:0:0:0:0:1" is "0:0:0:0:0:0:0:1", should be "localhost"​
​
        at PlatformNameServiceTest.testReverseLookup(PlatformNameServiceTest.java:64)​
        at PlatformNameServiceTest.main(PlatformNameServiceTest.java:26)​
​
msheppard at MARKS-LAPTOP /cygdrive/c/Users/msheppard/eclipse-workspace/JDK-Tests​
$ /cygdrive/c/Development/jdk-installs/jdk-12/bin/java  -Djava.net.preferIPv6Addresses=true PlatformNameServiceTest​
############################  InetAddress == localhost/0:0:0:0:0:0:0:1​
retrieved address == [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1] equal to expected address == [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1]​
testReverseLookup: host addr 0000:0000:0000:0000:0000:0000:0000:0001 : expected host name localhost​
Exception in thread "main" java.lang.RuntimeException: reverse lookup of "0000:0000:0000:0000:0000:0000:0000:0001" is "0:0:0:0:0:0:0:1", should be "localhost"​
​
        at PlatformNameServiceTest.testReverseLookup(PlatformNameServiceTest.java:64)​
        at PlatformNameServiceTest.main(PlatformNameServiceTest.java:27)​


________________________________
From: net-dev <net-dev-bounces at openjdk.java.net> on behalf of Arthur Eubanks <aeubanks at google.com>
Sent: Monday 13 May 2019 17:59
To: Chris Hegarty
Cc: OpenJDK Network Dev list
Subject: Re: [ipv6] RFR: 8223737: HostsFileNameService doesn't handle IPv6 literal addresses correctly



From: Chris Hegarty <chris.hegarty at oracle.com<mailto:chris.hegarty at oracle.com>>
Date: Mon, May 13, 2019 at 9:33 AM
To: Arthur Eubanks, OpenJDK Network Dev list

Arthur,

On 11/05/2019 01:17, Arthur Eubanks wrote:
> Bug: https://bugs.openjdk.java.net/browse/JDK-8223737
> Webrev: http://cr.openjdk.java.net/~aeubanks/8223737/webrev.00/index.html
>
> HostsFileNameService doesn't handle IPv6 literal addresses correctly.
> For example, ::1 and 0:0:0:0:0:0:0:1 should yield the same output.
>
> Rather than comparing address strings, compare the address byte arrays.

Comparison of byte arrays is much better. The changes look good.

Trivially, can I ask you to please include a number of other reverse
lookup's to fill out the test a little. Here's what I came up with:

     testReverseLookup("10.2.3.4", "testHost.testDomain");

     // ::1 and 0:0:0:0:0:0:0:1 should map to ip6-localhost
     testReverseLookup("::1", "ip6-localhost");
     testReverseLookup("0:0:0:0:0:0:0:1", "ip6-localhost");

testReverseLookup("0000:0000:0000:0000:0000:0000:0000:0001","ip6-localhost");

     testReverseLookup("fe00::0", "ip6-localnet");
     testReverseLookup("fe00:0:0:0:0:0:0:0", "ip6-localnet");
     testReverseLookup("fe00:0000:0000:0000:0000:0000:0000:0000",
"ip6-localnet");

     testReverseLookup("fe80::1", "link-local-host");
     testReverseLookup("fe80:000:0:00:0:000:00:1", "link-local-host");
     testReverseLookup("fe80:0000:0000:0000:0000:0000:0000:0001",
"link-local-host");

Thanks,
-Chris.
Added the extra reverse lookups.

I also noticed that the test is catching UnknownHostException and not rethrowing it, so I removed the try/catch.

Updated webrev: http://cr.openjdk.java.net/~aeubanks/8223737/webrev.01/index.html
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://mail.openjdk.java.net/pipermail/net-dev/attachments/20190513/a35f9ee4/attachment.html>