8373704: Improve "SocketException: Protocol family unavailable" message

[MBaesken]

In JDK-8373676
we noticed a "SocketException: Protocol family unavailable" because of missing ipv6 support. We could improve this exception and tell that the ipv6 support is not available or something related.

---

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Issue

• JDK-8373704: Improve "SocketException: Protocol family unavailable" message (Enhancement - P4)

Reviewers

• Lutz Schmidt (@RealLucy - Reviewer)
• Jaikiran Pai (@jaikiran - Reviewer)

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[openjdk]

@MBaesken This change now passes all automated pre-integration checks.

ℹ️ This project also has non-automated pre-integration requirements. Please see the file CONTRIBUTING.md for details.

After integration, the commit message for the final commit will be:

8373704: Improve "SocketException: Protocol family unavailable" message

Reviewed-by: lucy, jpai

You can use pull request commands such as /summary, /contributor and /issue to adjust it as needed.

At the time when this comment was updated there had been 132 new commits pushed to the master branch:

• 53824cf: 8343809: Add requires tag to mark tests that are incompatible with exploded image
• 2daf12e: 8374465: Spurious dot in documentation for JVMTI ClassLoad
• 3439512: 8374317: Change GCM IV size to 12 bytes when encrypting/decrypting TLS session ticket
• ... and 129 more: https://git.openjdk.org/jdk/compare/89e77512fd44b6a0299ab36db15142e7544899f3...master

As there are no conflicts, your changes will automatically be rebased on top of these commits when integrating. If you prefer to avoid this automatic rebasing, please check the documentation for the /integrate command for further details.

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[mlbridge]

Webrevs

• 01: Full - Incremental (efaa1512)
• 00: Full (ca4952cd)

[RealLucy]

Changes look good.

[AlanBateman]

we noticed a "SocketException: Protocol family unavailable" because of missing ipv6 support. We could improve this exception and tell that the ipv6 support is not available or something related.

Would it be possible to say which method or test failure lead to this? I'm wondering how we end up calling it with an IPv6 address when not supported.

[MBaesken]

Hi Alan, it was the test javax/net/ssl/HttpsURLConnection/SubjectAltNameIP.java .
See https://bugs.openjdk.org/browse/JDK-8373676 .

Error :
command: main SubjectAltNameIP [::1]
reason: User specified action: run main/othervm SubjectAltNameIP [::1]
started: Sun Dec 14 21:22:53.422 CET 2025
Mode: othervm [/othervm specified]
Additional options from @modules: --add-modules java.base --add-exports java.base/sun.net.util=ALL-UNNAMED
Process id: 14723
finished: Sun Dec 14 21:22:59.728 CET 2025
elapsed time (seconds): 6.306
----------configuration:(4/101)----------
Boot Layer
  add modules: java.base
  add exports: java.base/sun.net.util ALL-UNNAMED

----------System.out:(0/0)----------
----------System.err:(26/1574)----------
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$MainTask.run(MainWrapper.java:138)
at java.base/java.lang.Thread.run(Thread.java:1516)
**Caused by: java.net.SocketException: Protocol family unavailable**
at java.base/sun.nio.ch.Net.bind0(Native Method)
at java.base/sun.nio.ch.Net.bind(Net.java:525)
at java.base/sun.nio.ch.Net.bind(Net.java:514)
at java.base/sun.nio.ch.NioSocketImpl.bind(NioSocketImpl.java:641)
at java.base/java.net.ServerSocket.bind(ServerSocket.java:326)
at java.base/java.net.ServerSocket.<init>(ServerSocket.java:222)
at java.base/javax.net.ssl.SSLServerSocket.<init>(SSLServerSocket.java:155)
at java.base/sun.security.ssl.SSLServerSocketImpl.<init>(SSLServerSocketImpl.java:80)
at java.base/sun.security.ssl.SSLServerSocketFactoryImpl.createServerSocket(SSLServerSocketFactoryImpl.java:87)
at SubjectAltNameIP.doServerSide(SubjectAltNameIP.java:106)
at SubjectAltNameIP.lambda$startServer$0(SubjectAltNameIP.java:203)
... 1 more

[MBaesken]

Changes look good.

Thanks for the review !

[AlanBateman]

Hi Alan, it was the test javax/net/ssl/HttpsURLConnection/SubjectAltNameIP.java .
See https://bugs.openjdk.org/browse/JDK-8373676 .

Thanks, just checking that there was an issue to track fixing the test.

[jaikiran]

Hello Matthias, this looks OK to me. Please run tier2 tests before integrating.

[MBaesken]

Thanks for the reviews ! I observed no issues in the tier2 tests .

/integrate

[openjdk]

Going to push as commit 1630382.
Since your change was applied there have been 133 commits pushed to the master branch:

• 6eaabed: 8373722: [TESTBUG] compiler/vectorapi/TestVectorOperationsWithPartialSize.java fails intermittently
• 53824cf: 8343809: Add requires tag to mark tests that are incompatible with exploded image
• 2daf12e: 8374465: Spurious dot in documentation for JVMTI ClassLoad
• ... and 130 more: https://git.openjdk.org/jdk/compare/89e77512fd44b6a0299ab36db15142e7544899f3...master

Your commit was automatically rebased without conflicts.

[openjdk]

@MBaesken Pushed as commit 1630382.

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