* Re: [Bugme-new] [Bug 15720] New: IPv6's ipv4-compatibility addresses don't bind
[not found] <bug-15720-10286@https.bugzilla.kernel.org/>
@ 2010-04-13 1:22 ` Andrew Morton
2010-04-13 15:06 ` Brian Haley
0 siblings, 1 reply; 2+ messages in thread
From: Andrew Morton @ 2010-04-13 1:22 UTC (permalink / raw)
To: netdev; +Cc: bugzilla-daemon, bugme-daemon, charles
(switched to email. Please respond via emailed reply-to-all, not via the
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On Wed, 7 Apr 2010 23:17:32 GMT bugzilla-daemon@bugzilla.kernel.org wrote:
> https://bugzilla.kernel.org/show_bug.cgi?id=15720
>
> Summary: IPv6's ipv4-compatibility addresses don't bind
A 2.6.9 -> 2.6.32 regression ;)
> Product: Networking
> Version: 2.5
> Kernel Version: 2.6.32-2-686-bigmem
> Platform: All
> OS/Version: Linux
> Tree: Mainline
> Status: NEW
> Severity: normal
> Priority: P1
> Component: IPV6
> AssignedTo: yoshfuji@linux-ipv6.org
> ReportedBy: charles@kde.org
> Regression: Yes
>
>
> When attempting to bind to an address using ipv4-compatibility, for example,
> "::ffff:127.0.0.1", Linux refuses to bind to that address when
> /proc/sys/net/ipv6/bindv6only is set.
>
> Yes, you could say "but you specifically told ipv6 to not bind to ipv4
> addresses!" However, ::ffff:127.0.0.1 is *clearly* an ipv4 address, it's not an
> alternate representation of an ipv6 address, it's an ipv4 address and only
> ipv4.
>
> This seems to not have been the case as of linux 2.6.9, although I'm not sure
> at what version this changed.
>
> It seems to me that the intent of "bindv6only" was to not bind to the ipv4
> address when you bind to all addresses (specifically ipv6 address "::"). So
> when you bind to ::, an ipv4 client connects to you, and it appears to be
> connecting from ::ffff:192.168.5.5. I don't think its intent was to effectively
> disable binding to ::ffff:x.x.x.x addresses - just breaking that feature makes
> no sense.
>
> The Linux 2.6.9 approach seems to match MacOS's (and I'm pretty sure Solaris's,
> too).
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [Bugme-new] [Bug 15720] New: IPv6's ipv4-compatibility addresses don't bind
2010-04-13 1:22 ` [Bugme-new] [Bug 15720] New: IPv6's ipv4-compatibility addresses don't bind Andrew Morton
@ 2010-04-13 15:06 ` Brian Haley
0 siblings, 0 replies; 2+ messages in thread
From: Brian Haley @ 2010-04-13 15:06 UTC (permalink / raw)
To: charles; +Cc: Andrew Morton, netdev, bugzilla-daemon, bugme-daemon
Andrew Morton wrote:
>> When attempting to bind to an address using ipv4-compatibility, for example,
>> "::ffff:127.0.0.1", Linux refuses to bind to that address when
>> /proc/sys/net/ipv6/bindv6only is set.
This is actually not a (deprecated) IPv4-compatible IPv6 address (::127.0.0.1),
but an IPv4-mapped IPv6 address.
>> It seems to me that the intent of "bindv6only" was to not bind to the ipv4
>> address when you bind to all addresses (specifically ipv6 address "::"). So
>> when you bind to ::, an ipv4 client connects to you, and it appears to be
>> connecting from ::ffff:192.168.5.5. I don't think its intent was to effectively
>> disable binding to ::ffff:x.x.x.x addresses - just breaking that feature makes
>> no sense.
It is documented in ip-sysctl.txt:
bindv6only - BOOLEAN
Default value for IPV6_V6ONLY socket option,
which restricts use of the IPv6 socket to IPv6 communication
only.
TRUE: disable IPv4-mapped address feature
FALSE: enable IPv4-mapped address feature
Default: FALSE (as specified in RFC2553bis)
-Brian
^ permalink raw reply [flat|nested] 2+ messages in thread
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[not found] <bug-15720-10286@https.bugzilla.kernel.org/>
2010-04-13 1:22 ` [Bugme-new] [Bug 15720] New: IPv6's ipv4-compatibility addresses don't bind Andrew Morton
2010-04-13 15:06 ` Brian Haley
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