REDIRECT and IPv6

Greetings,

Pardon if this is a dumb question. But I have searched the
web, and the
source code for a solution to this one and have reached a
brick wall.

I'm upgrading a user-space proxy (squid3) which has in the
past done
transparent connections under IPv4-only using
SO_ORIGINAL_DST.

The Firewall/router uses iptables and REDIRECT port 80
outbound to port
81. All is fine and dandy when squid listens on 0.0.0.0:81.

With the new code I have to use an IPv6 socket ( [::]:81 )
as the
receiver. With that getsockopt(..., SO_ORIGINAL_DST, ...)
always returns
err "92 Protocol not supported." regardless of the
IP-level parameters
passed in.

NOTE: All traffic for testing so far has been from IPv4
clients to what
they think is an IPv4 server, but with a dual-enabled
middleman. The
'middleman' Software is iptables 1.3.6 on Debian
2.6.21-2-486 (unstable),
squid3 built with g++ 4.1.3.

Can anyone point me in the right direction for a solution
that will work?
Ideally one that is protocol-independant, but anything is
welcome even an
'upgrade to X'.

Amos Jeffries
Squid3 Development Team

squid3treenet.co.nz wrote:
> Greetings,
> 
> Pardon if this is a dumb question. But I have searched
the web, and the
> source code for a solution to this one and have reached
a brick wall.
> 
> I'm upgrading a user-space proxy (squid3) which has in
the past done
> transparent connections under IPv4-only using
SO_ORIGINAL_DST.
> 
> The Firewall/router uses iptables and REDIRECT port 80
outbound to port
> 81. All is fine and dandy when squid listens on
0.0.0.0:81.
> 
> With the new code I have to use an IPv6 socket (
[::]:81 ) as the
> receiver. With that getsockopt(..., SO_ORIGINAL_DST,
...) always returns
> err "92 Protocol not supported." regardless
of the IP-level parameters
> passed in.
> 
> NOTE: All traffic for testing so far has been from IPv4
clients to what
> they think is an IPv4 server, but with a dual-enabled
middleman. The
> 'middleman' Software is iptables 1.3.6 on Debian
2.6.21-2-486 (unstable),
> squid3 built with g++ 4.1.3.


You're right, nf_conntrack_ipv4 only registeres
SO_ORIGINAL_DST for
AF_INET, changing that should make it work I believe. I feel
like
I'm missing something though ..

From: Patrick McHardy <kabertrash.net>
Date: Thu, 19 Jul 2007 10:59:55 +0200

> squid3treenet.co.nz wrote:
> > Greetings,
> > 
> > Pardon if this is a dumb question. But I have
searched the web, and the
> > source code for a solution to this one and have
reached a brick wall.
> > 
> > I'm upgrading a user-space proxy (squid3) which
has in the past done
> > transparent connections under IPv4-only using
SO_ORIGINAL_DST.
> > 
> > The Firewall/router uses iptables and REDIRECT
port 80 outbound to port
> > 81. All is fine and dandy when squid listens on
0.0.0.0:81.
> > 
> > With the new code I have to use an IPv6 socket (
[::]:81 ) as the
> > receiver. With that getsockopt(...,
SO_ORIGINAL_DST, ...) always returns
> > err "92 Protocol not supported."
regardless of the IP-level parameters
> > passed in.
> > 
> > NOTE: All traffic for testing so far has been from
IPv4 clients to what
> > they think is an IPv4 server, but with a
dual-enabled middleman. The
> > 'middleman' Software is iptables 1.3.6 on Debian
2.6.21-2-486 (unstable),
> > squid3 built with g++ 4.1.3.
> 
> 
> You're right, nf_conntrack_ipv4 only registeres
SO_ORIGINAL_DST for
> AF_INET, changing that should make it work I believe. I
feel like
> I'm missing something though ..

I wrote getorigdst() for IPv6 at once but threw away it
because of no IPv6 NAT  I hope
that new tproxy will support IPv6 in future.

-- Yasuyuki Kozakai

In article <469F280B.3070900trash.net> (at Thu, 19
Jul 2007 10:59:55 +0200), Patrick McHardy <kabertrash.net> says:

> You're right, nf_conntrack_ipv4 only registeres
SO_ORIGINAL_DST for
> AF_INET, changing that should make it work I believe. I
feel like
> I'm missing something though ..

BTW, the name of the socket option is rather bogus.
It should be named IP_xxx, not SO_xxx because
it is in IP level, not in socket level...

--yoshfuji