RFR: 8373676: Test javax/net/ssl/HttpsURLConnection/SubjectAltNameIP.java fails on a machine without IPV6

[Matthias Baesken]

On Mon, 15 Dec 2025 13:32:17 GMT, Daniel Fuchs <dfuchs at openjdk.org> wrote:

>> We have a Linux machine with IPV6 disabled.
>> There the test javax/net/ssl/HttpsURLConnection/SubjectAltNameIP.java fails.
>> Error is
>> 
>> java.lang.RuntimeException: Server failed to start.
>> at SubjectAltNameIP.doClientSide(SubjectAltNameIP.java:139)
>> at SubjectAltNameIP.<init>(SubjectAltNameIP.java:189)
>> at SubjectAltNameIP.main(SubjectAltNameIP.java:176)
>> at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:104)
>> at java.base/java.lang.reflect.Method.invoke(Method.java:565)
>> at com.sun.javatest.regtest.agent.MainWrapper$MainTask.run(MainWrapper.java:138)
>> at java.base/java.lang.Thread.run(Thread.java:1516)
>> Caused by: java.net.SocketException: Protocol family unavailable
>> 
>> 
>> After looking into the test, it turned out the IPV6 address `::1`  was passed in the notion `[::1] `to the isIPv6LiteralAddress, but this method must get the address without '[' and ']' .
>> Additionally I adjusted the exception a bit so that it directly mentions IPV6 and not just some 'protol family' .
>
> src/java.base/unix/native/libnet/net_util_md.c line 288:
> 
>> 286:         if (family != java_net_InetAddress_IPv4) {
>> 287:             if (ipv6av) {
>> 288:                 JNU_ThrowByName(env, JNU_JAVANETPKG "SocketException", "Protocol family ipv6, ipv6 on machine available");
> 
> This exception does not really make sense. Are you really sure it's possible to get here?

Looks like to get into the else case starting at line 284 or before the patch like 282 ,  ipv6_available() / ipv6av can be false ; or also the second part of the if check can be false  

!(family == java_net_InetAddress_IPv4 &&  v4MappedAddress == JNI_FALSE))

so we should distinguish the 2 cases. Not sure if this really happens, on our system showing the error we got the other one `Caused by: java.net.SocketException: Protocol family ipv6, ipv6 on machine unavailable`

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PR Review Comment: https://git.openjdk.org/jdk/pull/28825#discussion_r2619541006