Re: Linux.conf.au 2003 Report

On Thu, Jan 30, 2003 at 08:21:09PM -0600, Greg Copeland wrote:
>
> IPv6 has some provisions to help people migrate toward it (from IPv4),
> however, IPv6 is a distinctly different protocol.

The ipv4 mapped ipv6 addresses are to help migrate, but it
actually makes things worse. If this wouldn't be the case, some
software wouldn't look as ugly as it does now.

Then there is the "problem" that BSD no longer really supports
the ipv4 mapped ipv6 addresses. It will refuse to use such an
address on an AF_INET6 socket, while that (still) works on other
OSs. The badly ported software will not work on them.

> It doesn't help the
> confusion that many OS's try to confuse programmers by exposing a single
> socket interface, etc. Simple fact remains, IPv6 is not IPv4.

It's a good things that the socket interface can actually work
with all protocol! It doesn't only work with AF_INET, but also
AF_UNIX, and probably others. It's a good things that things
like socket(), bind(), connect() don't need to be replaced by
other things.

The new protocol independed API for translation between
host name and address, in both text and binary representation is
also a good thing.

The struct addrinfo is really useful, since you can store all
info you need in it for all calls to the socket API. The ipv6
patch really should make better use of it, both if you have and
don't have ipv6 support, and get rid of most of those #ifdefs.

Kurt