[Bug libgcj/27066] New: libgcj native socket code does not support IPv6

[Bug libgcj/27066] New: libgcj native socket code does not support IPv6

[cjw at daneel dot dyndns dot org]

Java Sockets do not know on creation if they will be used for IPv6 or IPv4, so
the gnu::java::net::PlainSocketImpl::create method should use PF_INET6 instead
of AF_INET. The other methods - bind and connect - must then translate IPv4
addresses to IPv4-in-IPv6. Behavior with HAVE_INET6 not defined should probably
not be changed. The code is in libjava/gnu/java/net/natPlainSocketImplPosix.cc
.


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           Summary: libgcj native socket code does not support IPv6
           Product: gcc
           Version: 4.1.1
            Status: UNCONFIRMED
          Severity: enhancement
          Priority: P3
         Component: libgcj
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: cjw at daneel dot dyndns dot org
  GCC host triplet: powerpc-mandriva-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27066

[Bug libgcj/27066] libgcj native socket code does not support IPv6

[cjw at daneel dot dyndns dot org]

------- Comment #1 from cjw at daneel dot dyndns dot org  2006-04-06 19:43 -------
Created an attachment (id=11219)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=11219&action=view)
Example patch to fix IPv6 support


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27066

[Bug libgcj/27066] libgcj native socket code does not support IPv6

[mckinlay at redhat dot com]

------- Comment #2 from mckinlay at redhat dot com  2006-04-06 20:08 -------
I'm not sure I follow this. create() does not get called until the socket is
bound. Don't we know at that point whether we're binding to an IPV4 or IPV6
address?


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27066

[Bug libgcj/27066] libgcj native socket code does not support IPv6

[cjw at daneel dot dyndns dot org]

------- Comment #3 from cjw at daneel dot dyndns dot org  2006-04-06 22:38 -------
AFAICT create() is called in Socket's getImpl() method, which in turn is called
from e.g. setTcpNoDelay() and calling that after a plain "new Socket()" means
no bind was done yet... Anyway, the address is not passed to create() so this
information is currently not available even when create() is called from
bind().


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27066

[Bug libgcj/27066] libgcj native socket code does not support IPv6

[mckinlay at redhat dot com]

------- Comment #4 from mckinlay at redhat dot com  2006-04-11 18:08 -------
You are correct - I didn't notice that setTcpNoDelay, etc, call getImpl() -
however, this could be fixed if neccessary.

The question is whether this fix is the best one. Is there any disadvantage
(performance or otherwise) to always using PF_INET6 sockets, even for IPv4
addresses?


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mckinlay at redhat dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2006-04-11 18:08:20
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27066

[Bug libgcj/27066] libgcj native socket code does not support IPv6

[cjw at daneel dot dyndns dot org]

------- Comment #5 from cjw at daneel dot dyndns dot org  2006-04-12 19:08 -------
There are probably disadvantages: it doesn't seem possible to bind to 127.0.0.1
this way. So choosing the socket domain that matches the address to
bind/connect to is probably a good idea. I thought other java implementations
use the IPv4-in-IPv6 system but now I'm not so sure about that.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27066