[Mimedefang] [Patch] relay_is_* not ipv6 friendly
apex at xepa.nl
Tue Feb 2 14:44:48 EST 2010
On 2-2-2010 19:01, David F. Skoll wrote:
> In other words, what is the difference between an SMTP client coming
> from "::ffff:192.168.10.1" or "192.168.10.1" ?
or ::ffff:c0a8:a01. Well not a lot I would guess except that one is ipv6
the other ipv4. Guess it all depends on semantics .. probably nothing
functional but I thought I would bring it up.
> I made the C code recognize mapped IPv4 addresses and convert them to
> plain IPv4 addresses to simplify the filter code. If you get an IPv4
> address, fine... you can handle it. Similarly, if you get an IPv6
> address, you don't need to worry about the (IMO hackish and ugly)
> IPv4-mapped special case.
No questions remarks there :)
>> Say you are on a ipv4 only network you would never receive those
>> addresses while if you are on a ipv6 only network all of a sudden you
>> might get data from an ipv4 address (but you are ipv6 only), that might
>> throw a spanner in the works.
> How so?
Well database and code could only assume that they get ipv6 addresses.
But then I guess there is no one stopping you encoding all ipv4 as 6 :)
and I guess we can revisit when more of the world is using ipv6 .. like
in 100 years :)
> I doubt any RBL would list the IPv6-variant without also listing the
> IPv4 variant.
I have yet to use RBL's that even deal with ipv6 let alone ipv4 mapped
I will see when I can get the patch altered not to take into account the
ipv6 mapped ipv4, as the c code handles that part.
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