Hi Arthur,
On 17/04/2019 07:54, Alan Bateman wrote:
On 16/04/2019 22:34, Arthur Eubanks wrote:
Hi,
Copied from the bug https://bugs.openjdk.java.net/browse/JDK-8222562:
Some of the networking code tries to support dual socket support.
However, it doesn't work with IPv6 only systems.
setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, 0) returns a failure with
errno EAFNOSUPPORT, and then the networking code bails. It should not
bail when it sees that trying to set IPV6_V6ONLY fails.
webrev:
http://cr.openjdk.java.net/~aeubanks/ipv6setsockopt/webrev.00/index.html
One thing to note is that similar code exists in the Windows part of
the networking code (e.g.
java.base/windows/native/libnet/PlainSocketImpl.c), but I don't know
how to test Windows code so I'm only touching the Unix-specific part.
This code is compiled on other Unix-like ports too so I think we should
at least try to see if they also return EAFNOSUPPORT when configured for
IPv6-only.
Also should we have an ipv4_available() utility similar
to ipv6_available() and check that before making the decision not
to bail on EAFNOSUPPORT? Or would that be a chicken and egg problem?
best regards,
-- daniel
-Alan
